Sample records for yellow fever outbreak

  1. Yellow Fever Outbreak, Southern Sudan, 2003

    PubMed Central

    Onyango, Clayton O.; Grobbelaar, Antoinette A.; Gibson, Georgina V.F.; Sang, Rosemary C.; Sow, Abdourahmane; Swanepoel, Robert

    2004-01-01

    In May 2003, an outbreak of fatal hemorrhagic fever, caused by yellow fever virus, occurred in southern Sudan. Phylogenetic analysis showed that the virus belonged to the East African genotype, which supports the contention that yellow fever is endemic in East Africa with the potential to cause large outbreaks in humans. PMID:15498174

  2. Yellow Fever outbreaks in unvaccinated populations, Brazil, 2008-2009.

    PubMed

    Romano, Alessandro Pecego Martins; Costa, Zouraide Guerra Antunes; Ramos, Daniel Garkauskas; Andrade, Maria Auxiliadora; Jayme, Valéria de Sá; Almeida, Marco Antônio Barreto de; Vettorello, Kátia Campomar; Mascheretti, Melissa; Flannery, Brendan

    2014-03-01

    Due to the risk of severe vaccine-associated adverse events, yellow fever vaccination in Brazil is only recommended in areas considered at risk for disease. From September 2008 through June 2009, two outbreaks of yellow fever in previously unvaccinated populations resulted in 21 confirmed cases with 9 deaths (case-fatality, 43%) in the southern state of Rio Grande do Sul and 28 cases with 11 deaths (39%) in Sao Paulo state. Epizootic deaths of non-human primates were reported before and during the outbreak. Over 5.5 million doses of yellow fever vaccine were administered in the two most affected states. Vaccine-associated adverse events were associated with six deaths due to acute viscerotropic disease (0.8 deaths per million doses administered) and 45 cases of acute neurotropic disease (5.6 per million doses administered). Yellow fever vaccine recommendations were revised to include areas in Brazil previously not considered at risk for yellow fever.

  3. Yellow Fever Outbreak - Kongo Central Province, Democratic Republic of the Congo, August 2016.

    PubMed

    Otshudiema, John O; Ndakala, Nestor G; Mawanda, Elande-Taty K; Tshapenda, Gaston P; Kimfuta, Jacques M; Nsibu, Loupy-Régence N; Gueye, Abdou S; Dee, Jacob; Philen, Rossanne M; Giese, Coralie; Murrill, Christopher S; Arthur, Ray R; Kebela, Benoit I

    2017-03-31

    On April 23, 2016, the Democratic Republic of the Congo's (DRC's) Ministry of Health declared a yellow fever outbreak. As of May 24, 2016, approximately 90% of suspected yellow fever cases (n = 459) and deaths (45) were reported in a single province, Kongo Central Province, that borders Angola, where a large yellow fever outbreak had begun in December 2015. Two yellow fever mass vaccination campaigns were conducted in Kongo Central Province during May 25-June 7, 2016 and August 17-28, 2016. In June 2016, the DRC Ministry of Health requested assistance from CDC to control the outbreak. As of August 18, 2016, a total of 410 suspected yellow fever cases and 42 deaths were reported in Kongo Central Province. Thirty seven of the 393 specimens tested in the laboratory were confirmed as positive for yellow fever virus (local outbreak threshold is one laboratory-confirmed case of yellow fever). Although not well-documented for this outbreak, malaria, viral hepatitis, and typhoid fever are common differential diagnoses among suspected yellow fever cases in this region. Other possible diagnoses include Zika, West Nile, or dengue viruses; however, no laboratory-confirmed cases of these viruses were reported. Thirty five of the 37 cases of yellow fever were imported from Angola. Two-thirds of confirmed cases occurred in persons who crossed the DRC-Angola border at one market city on the DRC side, where ≤40,000 travelers cross the border each week on market day. Strategies to improve coordination between health surveillance and cross-border trade activities at land borders and to enhance laboratory and case-based surveillance and health border screening capacity are needed to prevent and control future yellow fever outbreaks.

  4. Yellow Fever Outbreaks in Unvaccinated Populations, Brazil, 2008–2009

    PubMed Central

    Romano, Alessandro Pecego Martins; Costa, Zouraide Guerra Antunes; Ramos, Daniel Garkauskas; Andrade, Maria Auxiliadora; Jayme, Valéria de Sá; de Almeida, Marco Antônio Barreto; Vettorello, Kátia Campomar; Mascheretti, Melissa; Flannery, Brendan

    2014-01-01

    Due to the risk of severe vaccine-associated adverse events, yellow fever vaccination in Brazil is only recommended in areas considered at risk for disease. From September 2008 through June 2009, two outbreaks of yellow fever in previously unvaccinated populations resulted in 21 confirmed cases with 9 deaths (case-fatality, 43%) in the southern state of Rio Grande do Sul and 28 cases with 11 deaths (39%) in Sao Paulo state. Epizootic deaths of non-human primates were reported before and during the outbreak. Over 5.5 million doses of yellow fever vaccine were administered in the two most affected states. Vaccine-associated adverse events were associated with six deaths due to acute viscerotropic disease (0.8 deaths per million doses administered) and 45 cases of acute neurotropic disease (5.6 per million doses administered). Yellow fever vaccine recommendations were revised to include areas in Brazil previously not considered at risk for yellow fever. PMID:24625634

  5. Yellow Fever Outbreak, Imatong, Southern Sudan

    PubMed Central

    Ofula, Victor O.; Sang, Rosemary C.; Konongoi, Samson L.; Sow, Abdourahmane; De Cock, Kevin M.; Tukei, Peter M.; Okoth, Fredrick A.; Swanepoel, Robert; Burt, Felicity J.; Waters, Norman C.; Coldren, Rodney L.

    2004-01-01

    In May 2003, the World Health Organization received reports about a possible outbreak of a hemorrhagic disease of unknown cause in the Imatong Mountains of southern Sudan. Laboratory investigations were conducted on 28 serum samples collected from patients in the Imatong region. Serum samples from 13 patients were positive for immunoglobulin M antibody to flavivirus, and serum samples from 5 patients were positive by reverse transcription–polymerase chain reaction with both the genus Flavivirus–reactive primers and yellow fever virus–specific primers. Nucleotide sequencing of the amplicons obtained with the genus Flavivirus oligonucleotide primers confirmed yellow fever virus as the etiologic agent. Isolation attempts in newborn mice and Vero cells from the samples yielded virus isolates from five patients. Rapid and accurate laboratory diagnosis enabled an interagency emergency task force to initiate a targeted vaccination campaign to control the outbreak. PMID:15207058

  6. Lineage-Specific Real-Time RT-PCR for Yellow Fever Virus Outbreak Surveillance, Brazil.

    PubMed

    Fischer, Carlo; Torres, Maria C; Patel, Pranav; Moreira-Soto, Andres; Gould, Ernest A; Charrel, Rémi N; de Lamballerie, Xavier; Nogueira, Rita Maria Ribeiro; Sequeira, Patricia C; Rodrigues, Cintia D S; Kümmerer, Beate M; Drosten, Christian; Landt, Olfert; Bispo de Filippis, Ana Maria; Drexler, Jan Felix

    2017-11-01

    The current yellow fever outbreak in Brazil prompted widespread yellow fever virus (YFV) vaccination campaigns, imposing a responsibility to distinguish between vaccine- and wild-type YFV-associated disease. We developed novel multiplex real-time reverse transcription PCRs that differentiate between vaccine and American wild-type YFV. We validated these highly specific and sensitive assays in an outbreak setting.

  7. Phylogeny of Yellow Fever Virus, Uganda, 2016.

    PubMed

    Hughes, Holly R; Kayiwa, John; Mossel, Eric C; Lutwama, Julius; Staples, J Erin; Lambert, Amy J

    2018-08-17

    In April 2016, a yellow fever outbreak was detected in Uganda. Removal of contaminating ribosomal RNA in a clinical sample improved the sensitivity of next-generation sequencing. Molecular analyses determined the Uganda yellow fever outbreak was distinct from the concurrent yellow fever outbreak in Angola, improving our understanding of yellow fever epidemiology.

  8. Epidemiological, Clinical and Entomological Characteristics of Yellow Fever Outbreak in Darfur 2012.

    PubMed

    Alhakimi, Hamdi Abdulwahab; Mohamed, Omima Gadalla; Khogaly, Hayat Salah Eldin; Arafa, Khalid Ahmad Omar; Ahmed, Waled Amen

    2015-01-01

    The study aims at analyzing the epidemiological, clinical and entomological characteristics of Darfur yellow fever epidemic. It is a descriptive, cross-sectional study. According to operational case definition, suspected yellow fever cases are included in case spread sheet with variables like age, sex, locality, occupation, status of vaccination, onset of symptoms, presenting symptoms, date of blood sampling and confirmation of diagnosis either by laboratory results or epidemiological link. Data about important entomological indices were collected by surveys conducted in 17 localities of 3 Darfur states (Central, West and south Darfur). All Darfur states (especially Central Darfur) have been affected by Yellow Fever outbreak. There is a need to review the non-specific case definition of Yellow Fever which seems to overwhelm the system during outbreaks with cases of other endemic diseases. The significant risk factors of this outbreak included male sex, adult age, outdoor occupation and traditional mining. The fatality rate was significantly associated with vaccination status. The highest fatality rate was recorded by children less than 2 years old (42.9%). Generally, increase in certain entomological indices was followed by increase in number of reported cases 7 days later. Central Darfur state was significantly higher in most studied entomological indices.

  9. Epidemiological, Clinical and Entomological Characteristics of Yellow Fever Outbreak in Darfur 2012

    PubMed Central

    Alhakimi, Hamdi Abdulwahab; Mohamed, Omima Gadalla; Khogaly, Hayat Salah Eldin; Arafa, Khalid Ahmad Omar; Ahmed, Waled Amen

    2015-01-01

    The study aims at analyzing the epidemiological, clinical and entomological characteristics of Darfur yellow fever epidemic. It is a descriptive, cross-sectional study. According to operational case definition, suspected yellow fever cases are included in case spread sheet with variables like age, sex, locality, occupation, status of vaccination, onset of symptoms, presenting symptoms, date of blood sampling and confirmation of diagnosis either by laboratory results or epidemiological link. Data about important entomological indices were collected by surveys conducted in 17 localities of 3 Darfur states (Central, West and south Darfur). All Darfur states (especially Central Darfur) have been affected by Yellow Fever outbreak. There is a need to review the non-specific case definition of Yellow Fever which seems to overwhelm the system during outbreaks with cases of other endemic diseases. The significant risk factors of this outbreak included male sex, adult age, outdoor occupation and traditional mining. The fatality rate was significantly associated with vaccination status. The highest fatality rate was recorded by children less than 2 years old (42.9%). Generally, increase in certain entomological indices was followed by increase in number of reported cases 7 days later. Central Darfur state was significantly higher in most studied entomological indices. PMID:29546100

  10. Yellow Fever outbreak in Darfur, Sudan in October 2012; the initial outbreak investigation report.

    PubMed

    Soghaier, Mohammed A; Hagar, Ahmed; Abbas, Mohammed A; Elmangory, Mutasim M; Eltahir, Khalid M; Sall, Amadou A

    2013-10-01

    Sudan is subject to repeated outbreaks, including Viral Hemorrhagic Fever (VHF), which is considered to be a very serious illness. Yellow Fever (YF) outbreaks in Sudan have been reported from the 1940s through 2005. In 2012, a new outbreak of YF occurred in the Darfur region. To identify the potential for an outbreak, to diagnose the disease and to be able to recognize its cause among the initial reported cases. >This is a descriptive and investigative field study that applies standard communicable disease outbreak investigation steps. The study involved clinical, serological, entomological and environmental surveys. The field investigation confirmed the outbreak and identified its cause to be YF. National surveillance systems should be strong enough to detect VHFs in a timely manner. Local health facilities should be prepared to promptly treat the initial cases because the case fatality ratios (CFRs) are usually very high among the index cases. Copyright © 2013 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  11. First recorded outbreak of yellow fever in Kenya, 1992-1993. II. Entomologic investigations.

    PubMed

    Reiter, P; Cordellier, R; Ouma, J O; Cropp, C B; Savage, H M; Sanders, E J; Marfin, A A; Tukei, P M; Agata, N N; Gitau, L G; Rapuoda, B A; Gubler, D J

    1998-10-01

    The first recorded outbreak of yellow fever in Kenya occurred from mid-1992 through March 1993 in the south Kerio Valley, Rift Valley Province. We conducted entomologic studies in February-March 1993 to identify the likely vectors and determine the potential for transmission in the surrounding rural and urban areas. Mosquitoes were collected by landing capture and processed for virus isolation. Container surveys were conducted around human habitation. Transmission was mainly in woodland of varying density, at altitudes of 1,300-1,800 m. The abundance of Aedes africanus in this biotope, and two isolations of virus from pools of this species, suggest that it was the principal vector in the main period of the outbreak. A third isolate was made from a pool of Ae. keniensis, a little-known species that was collected in the same biotope. Other known yellow fever vectors that were collected in the arid parts of the valley may have been involved at an earlier stage of the epidemic. Vervet monkeys and baboons were present in the outbreak area. Peridomestic mosquito species were absent but abundant at urban sites outside the outbreak area. The entomologic and epidemiologic evidence indicate that this was a sylvatic outbreak in which human cases were directly linked to the epizootic and were independent of other human cases. The region of the Kerio Valley is probably subject to recurrent wandering epizootics of yellow fever, although previous episodes of scattered human infection have gone unrecorded. The risk that the disease could emerge as an urban problem in Kenya should not be ignored.

  12. Immunogenicity of Fractional-Dose Vaccine during a Yellow Fever Outbreak - Preliminary Report.

    PubMed

    Ahuka-Mundeke, Steve; Casey, Rebecca M; Harris, Jennifer B; Dixon, Meredith G; Nsele, Pierre M; Kizito, Gabriel M; Umutesi, Grace; Laven, Janeen; Paluku, Gilson; Gueye, Abdou S; Hyde, Terri B; Sheria, Guylain K M; Muyembe-Tanfum, Jean-Jacques; Staples, J Erin

    2018-02-14

    Background In 2016, the response to a yellow fever outbreak in Angola and the Democratic Republic of Congo led to a global shortage of yellow fever vaccine. As a result, a fractional dose of the 17DD yellow fever vaccine (containing one fifth [0.1 ml] of the standard dose) was offered to 7.6 million children 2 years of age or older and nonpregnant adults in a preemptive campaign in Kinshasa. The goal of this study was to assess the immune response to the fractional dose in a large-scale campaign. Methods We recruited participants in four age strata at six vaccination sites. We assessed neutralizing antibody titers against yellow fever virus in blood samples obtained before vaccination and 28 to 35 days after vaccination, using a plaque reduction neutralization test with a 50% cutoff (PRNT 50 ). Participants with a PRNT 50 titer of 10 or higher at baseline were considered to be seropositive. Those with a baseline titer of less than 10 who became seropositive at follow-up were classified as having undergone seroconversion. Participants who were seropositive at baseline and who had an increase in the titer by a factor of 4 or more at follow-up were classified as having an immune response. Results Among 716 participants who completed follow-up, 705 (98%; 95% confidence interval [CI], 97 to 99) were seropositive after vaccination. Among 493 participants who were seronegative at baseline, 482 (98%; 95% CI, 96 to 99) underwent seroconversion. Among 223 participants who were seropositive at baseline, 148 (66%; 95% CI, 60 to 72) had an immune response. Lower baseline titers were associated with a higher probability of having an immune response (P<0.001). Conclusions A fractional dose of the 17DD yellow fever vaccine was effective at inducing seroconversion in most of the participants who were seronegative at baseline. These findings support the use of fractional-dose vaccination for outbreak control. (Funded by the U.S. Agency for International Development and the Centers

  13. Perinatal Yellow Fever: A Case Report.

    PubMed

    Diniz, Lilian Martins Oliveira; Romanelli, Roberta Maia Castro; de Carvalho, Andréa Lucchesi; Teixeira, Daniela Caldas; de Carvalho, Luis Fernando Andrade; Cury, Verônica Ferreira; Filho, Marcelo Pereira Lima; Perígolo, Graciele; Heringer, Tiago Pires

    2018-04-09

    An outbreak of yellow fever in Brazil made it possible to assess different presentations of disease such as perinatal transmission. A pregnant woman was admitted to hospital with yellow fever symptoms. She was submitted to cesarean section and died due to fulminant hepatitis. On the 6th day the newborn developed liver failure and died 13 days later. Yellow fever PCR was positive for both.

  14. Fatal Yellow Fever in Travelers to Brazil, 2018.

    PubMed

    Hamer, Davidson H; Angelo, Kristina; Caumes, Eric; van Genderen, Perry J J; Florescu, Simin A; Popescu, Corneliu P; Perret, Cecilia; McBride, Angela; Checkley, Anna; Ryan, Jenny; Cetron, Martin; Schlagenhauf, Patricia

    2018-03-23

    Yellow fever virus is a mosquito-borne flavivirus that causes yellow fever, an acute infectious disease that occurs in South America and sub-Saharan Africa. Most patients with yellow fever are asymptomatic, but among the 15% who develop severe illness, the case fatality rate is 20%-60%. Effective live-attenuated virus vaccines are available that protect against yellow fever (1). An outbreak of yellow fever began in Brazil in December 2016; since July 2017, cases in both humans and nonhuman primates have been reported from the states of São Paulo, Minas Gerais, and Rio de Janeiro, including cases occurring near large urban centers in these states (2). On January 16, 2018, the World Health Organization updated yellow fever vaccination recommendations for Brazil to include all persons traveling to or living in Espírito Santo, São Paulo, and Rio de Janeiro states, and certain cities in Bahia state, in addition to areas where vaccination had been recommended before the recent outbreak (3). Since January 2018, 10 travel-related cases of yellow fever, including four deaths, have been reported in international travelers returning from Brazil. None of the 10 travelers had received yellow fever vaccination.

  15. Yellow fever cases in Asia: primed for an epidemic.

    PubMed

    Wasserman, Sean; Tambyah, Paul Anantharajah; Lim, Poh Lian

    2016-07-01

    There is currently an emerging outbreak of yellow fever in Angola. Cases in infected travellers have been reported in a number of other African countries, as well as in China, representing the first ever documented cases of yellow fever in Asia. There is a large Chinese workforce in Angola, many of whom may be unvaccinated, increasing the risk of ongoing importation of yellow fever into Asia via busy commercial airline routes. Large parts of the region are hyperendemic for the related Flavivirus dengue and are widely infested by Aedes aegypti, the primary mosquito vector of urban yellow fever transmission. The combination of sustained introduction of viraemic travellers, an ecology conducive to local transmission, and an unimmunized population raises the possibility of a yellow fever epidemic in Asia. This represents a major global health threat, particularly in the context of a depleted emergency vaccine stockpile and untested surveillance systems in the region. In this review, the potential for a yellow fever outbreak in Asia is discussed with reference to the ecological and historical forces that have shaped global yellow fever epidemiology. The limitations of surveillance and vector control in the region are highlighted, and priorities for outbreak preparedness and response are suggested. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  16. Yellow Fever in Africa: estimating the burden of disease and impact of mass vaccination from outbreak and serological data.

    PubMed

    Garske, Tini; Van Kerkhove, Maria D; Yactayo, Sergio; Ronveaux, Olivier; Lewis, Rosamund F; Staples, J Erin; Perea, William; Ferguson, Neil M

    2014-05-01

    Yellow fever is a vector-borne disease affecting humans and non-human primates in tropical areas of Africa and South America. While eradication is not feasible due to the wildlife reservoir, large scale vaccination activities in Africa during the 1940s to 1960s reduced yellow fever incidence for several decades. However, after a period of low vaccination coverage, yellow fever has resurged in the continent. Since 2006 there has been substantial funding for large preventive mass vaccination campaigns in the most affected countries in Africa to curb the rising burden of disease and control future outbreaks. Contemporary estimates of the yellow fever disease burden are lacking, and the present study aimed to update the previous estimates on the basis of more recent yellow fever occurrence data and improved estimation methods. Generalised linear regression models were fitted to a dataset of the locations of yellow fever outbreaks within the last 25 years to estimate the probability of outbreak reports across the endemic zone. Environmental variables and indicators for the surveillance quality in the affected countries were used as covariates. By comparing probabilities of outbreak reports estimated in the regression with the force of infection estimated for a limited set of locations for which serological surveys were available, the detection probability per case and the force of infection were estimated across the endemic zone. The yellow fever burden in Africa was estimated for the year 2013 as 130,000 (95% CI 51,000-380,000) cases with fever and jaundice or haemorrhage including 78,000 (95% CI 19,000-180,000) deaths, taking into account the current level of vaccination coverage. The impact of the recent mass vaccination campaigns was assessed by evaluating the difference between the estimates obtained for the current vaccination coverage and for a hypothetical scenario excluding these vaccination campaigns. Vaccination campaigns were estimated to have reduced the

  17. Yellow Fever in Africa: Estimating the Burden of Disease and Impact of Mass Vaccination from Outbreak and Serological Data

    PubMed Central

    Garske, Tini; Van Kerkhove, Maria D.; Yactayo, Sergio; Ronveaux, Olivier; Lewis, Rosamund F.; Staples, J. Erin; Perea, William; Ferguson, Neil M.

    2014-01-01

    Background Yellow fever is a vector-borne disease affecting humans and non-human primates in tropical areas of Africa and South America. While eradication is not feasible due to the wildlife reservoir, large scale vaccination activities in Africa during the 1940s to 1960s reduced yellow fever incidence for several decades. However, after a period of low vaccination coverage, yellow fever has resurged in the continent. Since 2006 there has been substantial funding for large preventive mass vaccination campaigns in the most affected countries in Africa to curb the rising burden of disease and control future outbreaks. Contemporary estimates of the yellow fever disease burden are lacking, and the present study aimed to update the previous estimates on the basis of more recent yellow fever occurrence data and improved estimation methods. Methods and Findings Generalised linear regression models were fitted to a dataset of the locations of yellow fever outbreaks within the last 25 years to estimate the probability of outbreak reports across the endemic zone. Environmental variables and indicators for the surveillance quality in the affected countries were used as covariates. By comparing probabilities of outbreak reports estimated in the regression with the force of infection estimated for a limited set of locations for which serological surveys were available, the detection probability per case and the force of infection were estimated across the endemic zone. The yellow fever burden in Africa was estimated for the year 2013 as 130,000 (95% CI 51,000–380,000) cases with fever and jaundice or haemorrhage including 78,000 (95% CI 19,000–180,000) deaths, taking into account the current level of vaccination coverage. The impact of the recent mass vaccination campaigns was assessed by evaluating the difference between the estimates obtained for the current vaccination coverage and for a hypothetical scenario excluding these vaccination campaigns. Vaccination campaigns

  18. [Present status of an arbovirus infection: yellow fever, its natural history of hemorrhagic fever, Rift Valley fever].

    PubMed

    Digoutte, J P

    1999-12-01

    In the early 20th century, when it was discovered that the yellow fever virus was transmitted in its urban cycle by Aedes aegypti, measures of control were introduced leading to its disappearance. Progressive neglect of the disease, however, led to a new outbreak in 1927 during which the etiological agent was isolated; some years later a vaccine was discovered and yellow fever disappeared again. In the 1960s, rare cases of encephalitis were observed in young children after vaccination and the administration of the vaccine was forbidden for children under 10 years. Five years later, a new outbreak of yellow fever in Diourbel, Senegal, was linked to the presence of Aedes aegypti. In the late 1970s, the idea of a selvatic cycle for yellow fever arose. Thanks to new investigative techniques in Senegal and Côte d'Ivoire, the yellow fever virus was isolated from the reservoir of virus and vectors. The isolated virus was identified in monkeys and several vectors: Aedes furcifer, Aedes taylori, Aedes luteocephalus. Most importantly, the virus was isolated in male mosquitoes. Until recently, the only known cycle had been that of Haddow in East Africa. The virus circulate in the canopea between monkeys and Aedes africanus. These monkeys infect Aedes bromeliae when they come to eat in banana plantations. This cycle does not occur in West Africa. Vertical transmission is the main method of maintenance of the virus through the dry season. "Reservoirs of virus" are often mentioned in medical literature, monkeys having a short viremia whereas mosquitoes remain infected throughout their life cycle. In such a selvatic cycle, circulation can reach very high levels and no child would be able to escape an infecting bite and yet no clinical cases of yellow fever have been reported. The virulence--as it affects man--of the yellow fever virus in its wild cycle is very low. In areas where the virus can circulate in epidemic form, two types of circulation can be distinguished

  19. Yellow fever in China is still an imported disease.

    PubMed

    Chen, Jun; Lu, Hongzhou

    2016-05-23

    Yellow fever is a vector-borne disease endemic to tropical regions of Africa and South America. A recent outbreak in Angola caused hundreds of deaths. Six cases of yellow fever imported from Angola were reported recently in China. This raised the question of whether it will spread in China and how it can be prevented. This article discusses the possibility of yellow fever transmission in China and the strategies to counter it.

  20. Concomitant outbreaks of yellow fever and hepatitis E virus in Darfur States, Sudan, 2012.

    PubMed

    Ahmed, Sarah S; Soghaier, Mohammed A; Mohammed, Sozan; Khogali, Hayat S; Osman, Muntasir M; Abdalla, Abdalla M

    2016-01-31

    Yellow fever (YF) is a vector-borne disease transmitted to humans by infected Aedes mosquitoes, while hepatitis E virus (HEV) is a waterborne disease that is transmitted through the fecal-oral route. Both diseases have very close clinical presentation, namely fever, jaundice, malaise, and dark urine; they differ in severity and outcome. In this cross-sectional, laboratory-based study, an attempt was made to measure the correlation of concomitant YF and HEV infection in Darfur States during the previous YF outbreak in 2012. Results found concomitant outbreaks of YF and HEV at the same time with very weak statistical correlation between the two infections during the outbreak period, with Cramer's V correlation 0.05 and insignificant p value of 0.86. This correlation indicates that clinicians and care providers in tropical areas have to deal with clinical case definitions used for disease surveillance very carefully since prevalence of HEV infection is relatively common and this increases the possibility of misclassification and missing YF cases, particularly initial index cases, in a season or outbreak.

  1. Yellow Fever

    MedlinePlus

    ... Testing Vaccine Information Testing for Vaccine Adverse Events Yellow fever Vaccine Continuing Education Course Yellow Fever Home Prevention Vaccine Vaccine Recommendations Reactions to Yellow Fever Vacine Yellow Fever Vaccine, Pregnancy, & ... Transmission Symptoms, Diagnosis, & Treatment Maps Africa ...

  2. [The fourth horseman: The yellow fever].

    PubMed

    Vallejos-Parás, Alfonso; Cabrera-Gaytán, David Alejandro

    2017-01-01

    Dengue virus three, Chikunguya and Zika have entered the national territory through the south of the country. Cases and outbreaks of yellow fever have now been identified in the Americas where it threatens to expand. Although Mexico has a robust epidemiological surveillance system for vector-borne diseases, our country must be alert in case of its possible introduction into the national territory. This paper presents theoretical assumptions based on factual data on the behavior of yellow fever in the Americas, as well as reflections on the epidemiological surveillance of vector-borne diseases.

  3. Increased risk of yellow fever infections among unvaccinated European travellers due to ongoing outbreak in Brazil, July 2017 to March 2018.

    PubMed

    Gossner, Céline M; Haussig, Joana M; de Bellegarde de Saint Lary, Chiara; Kaasik Aaslav, Kaja; Schlagenhauf, Patricia; Sudre, Bertrand

    2018-03-01

    Since December 2016, Brazil has faced a large outbreak of yellow fever with ca 1,500 confirmed human cases. In the first 2 months of 2018, Brazil reported almost as many cases as in 2017 as a whole. In these 2 months, five imported cases were reported among unvaccinated European travellers. Three had travelled to Ilha Grande, a popular destination among European tourists. Physicians and European travellers visiting Brazil should follow yellow fever vaccination recommendations.

  4. Yellow fever control in Cameroon: Where are we now and where are we going?

    PubMed Central

    Wiysonge, Charles Shey; Nomo, Emmanuel; Mawo, Jeanne; Ofal, James; Mimbouga, Julienne; Ticha, Johnson; Ndumbe, Peter M

    2008-01-01

    Background Cameroon is one of 12 African countries that bear most of the global burden of yellow fever. In 2002 the country developed a five-year strategic plan for yellow fever control, which included strategies for prevention as well as rapid detection and response to outbreaks when they occur. We have used data collected by the national Expanded Programme on Immunisation to assess the progress made and challenges faced during the first four years of implementing the plan. Methods In January 2003, case-based surveillance of suspected yellow fever cases was instituted in the whole country. A year later, yellow fever immunisation at nine months of age (the same age as routine measles immunisation) was introduced. Supplementary immunisation activities (SIAs), both preventive and in response to outbreaks, also formed an integral part of the yellow fever control plan. Each level of the national health system makes a synthesis of its activities and sends this to the next higher level at defined regular intervals; monthly for routine data and daily for SIAs. Results From 2004 to 2006 the national routine yellow fever vaccination coverage rose from 58.7% to 72.2%. In addition, the country achieved parity between yellow fever and measles vaccination coverage in 2005 and has since maintained this performance level. The number of suspected yellow fever cases in the country increased from 156 in 2003 to 859 in 2006, and the proportion of districts that reported at least one suspected yellow fever case per year increased from 31.4% to 68.2%, respectively. Blood specimens were collected from all suspected cases (within 14 days of onset of symptoms) and tested at a central laboratory for yellow fever IgM antibodies; leading to confirmation of yellow fever outbreaks in the health districts of Bafia, Méri and Ntui in 2003, Ngaoundéré Rural in 2004, Yoko in 2005 and Messamena in 2006. Owing to constraints in rapidly mobilising the necessary resources, reactive SIAs were only

  5. Yellow fever control in Cameroon: where are we now and where are we going?

    PubMed

    Wiysonge, Charles Shey; Nomo, Emmanuel; Mawo, Jeanne; Ofal, James; Mimbouga, Julienne; Ticha, Johnson; Ndumbe, Peter M

    2008-02-08

    Cameroon is one of 12 African countries that bear most of the global burden of yellow fever. In 2002 the country developed a five-year strategic plan for yellow fever control, which included strategies for prevention as well as rapid detection and response to outbreaks when they occur. We have used data collected by the national Expanded Programme on Immunisation to assess the progress made and challenges faced during the first four years of implementing the plan. In January 2003, case-based surveillance of suspected yellow fever cases was instituted in the whole country. A year later, yellow fever immunisation at nine months of age (the same age as routine measles immunisation) was introduced. Supplementary immunisation activities (SIAs), both preventive and in response to outbreaks, also formed an integral part of the yellow fever control plan. Each level of the national health system makes a synthesis of its activities and sends this to the next higher level at defined regular intervals; monthly for routine data and daily for SIAs. From 2004 to 2006 the national routine yellow fever vaccination coverage rose from 58.7% to 72.2%. In addition, the country achieved parity between yellow fever and measles vaccination coverage in 2005 and has since maintained this performance level. The number of suspected yellow fever cases in the country increased from 156 in 2003 to 859 in 2006, and the proportion of districts that reported at least one suspected yellow fever case per year increased from 31.4% to 68.2%, respectively. Blood specimens were collected from all suspected cases (within 14 days of onset of symptoms) and tested at a central laboratory for yellow fever IgM antibodies; leading to confirmation of yellow fever outbreaks in the health districts of Bafia, Méri and Ntui in 2003, Ngaoundéré Rural in 2004, Yoko in 2005 and Messamena in 2006. Owing to constraints in rapidly mobilising the necessary resources, reactive SIAs were only conducted in Bafia and M

  6. Yellow fever: a reemerging threat.

    PubMed

    Gardner, Christina L; Ryman, Kate D

    2010-03-01

    Yellow fever (YF) is a viral disease, endemic to tropical regions of Africa and the Americas, which principally affects humans and nonhuman primates and is transmitted via the bite of infected mosquitoes. Yellow fever virus (YFV) can cause devastating epidemics of potentially fatal, hemorrhagic disease. Despite mass vaccination campaigns to prevent and control these outbreaks, the risk of major YF epidemics, especially in densely populated, poor urban settings, both in Africa and South America, has greatly increased. Consequently, YF is considered an emerging, or reemerging disease of considerable importance. This article comprehensively reviews the history, microbiology, epidemiology, clinical presentation, diagnosis, and treatment of YFV, as well as the vaccines produced to combat YF. 2010 Elsevier Inc. All rights reserved.

  7. [Yellow fever].

    PubMed

    Sabbatani, Sergio; Fiorino, Sirio

    2007-06-01

    After the discovery of the New World, yellow fever proved to be an important risk factor of morbidity and mortality for Caribbean populations. In the following centuries epidemic risk, expanded by sea trade and travel, progressively reached the settlements in North America and Brazil as well as the Atlantic seaboard of tropical and equatorial Africa. In the eighteenth century and the first half of the nineteenth century epidemics of yellow fever were reported in some coastal towns in the Iberian peninsula, French coast, Great Britain and Italy, where, in 1804 at Leghorn, only one epidemic was documented. Prevention and control programs against yellow fever, developed at the beginning of the twentieth century in Cuba and in Panama, were a major breakthrough in understanding definitively its aetiology and pathogenesis. Subsequently, further advances in knowledge of yellow fever epidemiology were obtained when French scientists, working in West and Central Africa, showed that monkeys were major hosts of the yellow fever virus (the wild yellow fever virus), besides man. In addition, advances in research, contributing to the development of vaccines against the yellow fever virus in the first half of the nineteenth century, are reported in this paper.

  8. Lost trust: a yellow fever patient response.

    PubMed

    Runge, John S

    2013-12-13

    In the 19th century, yellow fever thrived in the tropical, urban trade centers along the American Gulf Coast. Industrializing and populated, New Orleans and Memphis made excellent habitats for the yellow fever-carrying Aedes aegypti mosquitoes and the virulence they imparted on their victims. Known for its jaundice and black, blood-filled vomit, the malady terrorized the region for decades, sometimes claiming tens of thousands of lives during the near annual summertime outbreaks. In response to the failing medical community, a small, pronounced population of sick and healthy laypeople openly criticized the efforts to rid the Gulf region of yellow jack. Utilizing newspapers and cartoons to vocalize their opinions, these critics doubted and mocked the medical community, contributing to the regional and seasonal dilemma yellow fever posed for the American South. These sentient expressions prove to be an early example of patient distrust toward caregivers, a current problem in clinical heath care.

  9. Lost Trust: A Yellow Fever Patient Response

    PubMed Central

    Runge, John S.

    2013-01-01

    In the 19th century, yellow fever thrived in the tropical, urban trade centers along the American Gulf Coast. Industrializing and populated, New Orleans and Memphis made excellent habitats for the yellow fever-carrying Aedes aegypti mosquitoes and the virulence they imparted on their victims. Known for its jaundice and black, blood-filled vomit, the malady terrorized the region for decades, sometimes claiming tens of thousands of lives during the near annual summertime outbreaks. In response to the failing medical community, a small, pronounced population of sick and healthy laypeople openly criticized the efforts to rid the Gulf region of yellow jack. Utilizing newspapers and cartoons to vocalize their opinions, these critics doubted and mocked the medical community, contributing to the regional and seasonal dilemma yellow fever posed for the American South. These sentient expressions prove to be an early example of patient distrust toward caregivers, a current problem in clinical heath care. PMID:24348220

  10. Phylodynamics of Yellow Fever Virus in the Americas: new insights into the origin of the 2017 Brazilian outbreak.

    PubMed

    Mir, Daiana; Delatorre, Edson; Bonaldo, Myrna; Lourenço-de-Oliveira, Ricardo; Vicente, Ana Carolina; Bello, Gonzalo

    2017-08-07

    Yellow fever virus (YFV) strains circulating in the Americas belong to two distinct genotypes (I and II) that have diversified into several concurrent enzootic lineages. Since 1999, YFV genotype I has spread outside endemic regions and its recent (2017) reemergence in non-endemic Southeastern Brazilian states fuels one of the largest epizootic of jungle Yellow Fever registered in the country. To better understand this phenomenon, we reconstructed the phylodynamics of YFV American genotypes using sequences from nine countries sampled along 60 years, including strains from Brazilian 2017 outbreak. Our analyses reveals that YFV genotypes I and II follow roughly similar evolutionary and demographic dynamics until the early 1990s, when a dramatic change in the diversification process of the genotype I occurred associated with the emergence and dissemination of a new lineage (here called modern). Trinidad and Tobago was the most likely source of the YFV modern-lineage that spread to Brazil and Venezuela around the late 1980s, where it replaced all lineages previously circulating. The modern-lineage caused all major YFV outbreaks detected in non-endemic South American regions since 2000, including the 2017 Brazilian outbreak, and its dissemination was coupled to the accumulation of several amino acid substitutions particularly within non-structural viral proteins.

  11. Yellow fever and Hajj: with all eyes on Zika, a familiar flavivirus remains a threat.

    PubMed

    Ahmed, Qanta A; Memish, Ziad A

    2016-12-01

    Hajj is among the world's largest mass gatherings, drawing between 2 and 3.5 million Muslims from 183 nations annually to perform pilgrimage in Mecca, Saudi Arabia. Infectious disease outbreaks can be imported both into the Hajj population and exported internationally by returning pilgrims. The domestic Saudi population can also be at risk of outbreaks traveling amid this mass migration. With yellow fever reported for the first time in China following the infection of expatriate Chinese workers in Angola and a full blown outbreak underway in wider West Africa, the prospect of yellow fever outbreaks in Asia threatens to impact Saudi Arabia, both during and beyond the Hajj season. With global focus trained on Zika, the rising threat of yellow fever cannot be overlooked. Strategies to mitigate risk to Saudi Arabia and the global population are thereby suggested.

  12. Yellow fever.

    PubMed

    Monath, Thomas P; Vasconcelos, Pedro F C

    2015-03-01

    Yellow fever, a mosquito-borne flavivirus disease occurs in tropical areas of South America and Africa. It is a disease of major historical importance, but remains a threat to travelers to and residents of endemic areas despite the availability of an effective vaccine for nearly 70 years. An important aspect is the receptivity of many non-endemic areas to introduction and spread of yellow fever. This paper reviews the clinical aspects, pathogenesis, and epidemiology of yellow fever, with an emphasis on recent changes in the distribution and incidence of the disease. Recent knowledge about yellow fever 17D vaccine mechanism of action and safety are discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Global yellow fever vaccination coverage from 1970 to 2016: an adjusted retrospective analysis.

    PubMed

    Shearer, Freya M; Moyes, Catherine L; Pigott, David M; Brady, Oliver J; Marinho, Fatima; Deshpande, Aniruddha; Longbottom, Joshua; Browne, Annie J; Kraemer, Moritz U G; O'Reilly, Kathleen M; Hombach, Joachim; Yactayo, Sergio; de Araújo, Valdelaine E M; da Nóbrega, Aglaêr A; Mosser, Jonathan F; Stanaway, Jeffrey D; Lim, Stephen S; Hay, Simon I; Golding, Nick; Reiner, Robert C

    2017-11-01

    Substantial outbreaks of yellow fever in Angola and Brazil in the past 2 years, combined with global shortages in vaccine stockpiles, highlight a pressing need to assess present control strategies. The aims of this study were to estimate global yellow fever vaccination coverage from 1970 through to 2016 at high spatial resolution and to calculate the number of individuals still requiring vaccination to reach population coverage thresholds for outbreak prevention. For this adjusted retrospective analysis, we compiled data from a range of sources (eg, WHO reports and health-service-provider registeries) reporting on yellow fever vaccination activities between May 1, 1939, and Oct 29, 2016. To account for uncertainty in how vaccine campaigns were targeted, we calculated three population coverage values to encompass alternative scenarios. We combined these data with demographic information and tracked vaccination coverage through time to estimate the proportion of the population who had ever received a yellow fever vaccine for each second level administrative division across countries at risk of yellow fever virus transmission from 1970 to 2016. Overall, substantial increases in vaccine coverage have occurred since 1970, but notable gaps still exist in contemporary coverage within yellow fever risk zones. We estimate that between 393·7 million and 472·9 million people still require vaccination in areas at risk of yellow fever virus transmission to achieve the 80% population coverage threshold recommended by WHO; this represents between 43% and 52% of the population within yellow fever risk zones, compared with between 66% and 76% of the population who would have required vaccination in 1970. Our results highlight important gaps in yellow fever vaccination coverage, can contribute to improved quantification of outbreak risk, and help to guide planning of future vaccination efforts and emergency stockpiling. The Rhodes Trust, Bill & Melinda Gates Foundation, the

  14. Spread of yellow fever virus outbreak in Angola and the Democratic Republic of the Congo 2015-16: a modelling study.

    PubMed

    Kraemer, Moritz U G; Faria, Nuno R; Reiner, Robert C; Golding, Nick; Nikolay, Birgit; Stasse, Stephanie; Johansson, Michael A; Salje, Henrik; Faye, Ousmane; Wint, G R William; Niedrig, Matthias; Shearer, Freya M; Hill, Sarah C; Thompson, Robin N; Bisanzio, Donal; Taveira, Nuno; Nax, Heinrich H; Pradelski, Bary S R; Nsoesie, Elaine O; Murphy, Nicholas R; Bogoch, Isaac I; Khan, Kamran; Brownstein, John S; Tatem, Andrew J; de Oliveira, Tulio; Smith, David L; Sall, Amadou A; Pybus, Oliver G; Hay, Simon I; Cauchemez, Simon

    2017-03-01

    Since late 2015, an epidemic of yellow fever has caused more than 7334 suspected cases in Angola and the Democratic Republic of the Congo, including 393 deaths. We sought to understand the spatial spread of this outbreak to optimise the use of the limited available vaccine stock. We jointly analysed datasets describing the epidemic of yellow fever, vector suitability, human demography, and mobility in central Africa to understand and predict the spread of yellow fever virus. We used a standard logistic model to infer the district-specific yellow fever virus infection risk during the course of the epidemic in the region. The early spread of yellow fever virus was characterised by fast exponential growth (doubling time of 5-7 days) and fast spatial expansion (49 districts reported cases after only 3 months) from Luanda, the capital of Angola. Early invasion was positively correlated with high population density (Pearson's r 0·52, 95% CI 0·34-0·66). The further away locations were from Luanda, the later the date of invasion (Pearson's r 0·60, 95% CI 0·52-0·66). In a Cox model, we noted that districts with higher population densities also had higher risks of sustained transmission (the hazard ratio for cases ceasing was 0·74, 95% CI 0·13-0·92 per log-unit increase in the population size of a district). A model that captured human mobility and vector suitability successfully discriminated districts with high risk of invasion from others with a lower risk (area under the curve 0·94, 95% CI 0·92-0·97). If at the start of the epidemic, sufficient vaccines had been available to target 50 out of 313 districts in the area, our model would have correctly identified 27 (84%) of the 32 districts that were eventually affected. Our findings show the contributions of ecological and demographic factors to the ongoing spread of the yellow fever outbreak and provide estimates of the areas that could be prioritised for vaccination, although other constraints such as vaccine

  15. Epidemiological and laboratory characterization of a yellow fever outbreak in northern Uganda, October 2010-January 2011.

    PubMed

    Wamala, Joseph F; Malimbo, Mugagga; Okot, Charles L; Atai-Omoruto, Ann D; Tenywa, Emmanuel; Miller, Jeffrey R; Balinandi, Stephen; Shoemaker, Trevor; Oyoo, Charles; Omony, Emmanuel O; Kagirita, Atek; Musenero, Monica M; Makumbi, Issa; Nanyunja, Miriam; Lutwama, Julius J; Downing, Robert; Mbonye, Anthony K

    2012-07-01

    In November 2010, following reports of an outbreak of a fatal, febrile, hemorrhagic illness in northern Uganda, the Uganda Ministry of Health established multisector teams to respond to the outbreak. This was a case-series investigation in which the response teams conducted epidemiological and laboratory investigations on suspect cases. The cases identified were line-listed and a data analysis was undertaken regularly to guide the outbreak response. Overall, 181 cases met the yellow fever (YF) suspected case definition; there were 45 deaths (case fatality rate 24.9%). Only 13 (7.5%) of the suspected YF cases were laboratory confirmed, and molecular sequencing revealed 92% homology to the YF virus strain Couma (Ethiopia), East African genotype. Suspected YF cases had fever (100%) and unexplained bleeding (97.8%), but jaundice was rare (11.6%). The overall attack rate was 13 cases/100000 population, and the attack rate was higher for males than females and increased with age. The index clusters were linked to economic activities undertaken by males around forests. This was the largest YF outbreak ever reported in Uganda. The wide geographical case dispersion as well as the male and older age preponderance suggests transmission during the outbreak was largely sylvatic and related to occupational activities around forests. Copyright © 2012 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  16. Yellow fever.

    PubMed

    Litvoc, Marcelo Nóbrega; Novaes, Christina Terra Gallafrio; Lopes, Max Igor Banks Ferreira

    2018-02-01

    The yellow fever (YF) virus is a Flavivirus, transmitted by Haemagogus, Sabethes or Aedes aegypti mosquitoes. The disease is endemic in forest areas in Africa and Latin America leading to epizootics in monkeys that constitute the reservoir of the disease. There are two forms of YF: sylvatic, transmitted accidentally when approaching the forests, and urban, which can be perpetuated by Aedes aegypti. In Brazil, the last case of urban YF occurred in 1942. Since then, there has been an expansion of transmission areas from the North and Midwest regions to the South and Southeast. In 2017, the country faced an important outbreak of the disease mainly in the states of Minas Gerais, Espírito Santo and Rio de Janeiro. In 2018, its reach extended from Minas Gerais toward São Paulo. Yellow fever has an incubation period of 3 to 6 days and sudden onset of symptoms with high fever, myalgia, headache, nausea/vomiting and increased transaminases. The disease ranges from asymptomatic to severe forms. The most serious forms occur in around 15% of those infected, with high lethality rates. These forms lead to renal, hepatic and neurological impairment, and bleeding episodes. Treatment of mild and moderate forms is symptomatic, while severe and malignant forms depend on intensive care. Prevention is achieved by administering the vaccine, which is an effective (immunogenicity at 90-98%) and safe (0.4 severe events per 100,000 doses) measure. In 2018, the first transplants in the world due to YF were performed. There is also an attempt to evaluate the use of active drugs against the virus in order to reduce disease severity.

  17. Yellow fever: epidemiology and prevention.

    PubMed

    Barnett, Elizabeth D

    2007-03-15

    Yellow fever continues to occur in regions of Africa and South America, despite the availability of effective vaccines. Recently, some cases of severe neurologic disease and multiorgan system disease have been described in individuals who received yellow fever vaccine. These events have focused attention on the need to define criteria for judicious use of yellow fever vaccine and to describe the spectrum of adverse events that may be associated with yellow fever vaccine. Describing host factors that would increase risk of these events and identifying potential treatment modalities for yellow fever and yellow fever vaccine-associated adverse events are subjects of intense investigation.

  18. The enigma of yellow fever in East Africa.

    PubMed

    Ellis, Brett R; Barrett, Alan D T

    2008-01-01

    Despite a safe and effective vaccine, there are approximately 200,000 cases, including 30,000 deaths, due to yellow fever virus (YFV) each year, of which 90% are in Africa. The natural history of YFV has been well described, especially in West Africa, but in East Africa yellow fever (YF) remains characterised by unpredictable focal periodicity and a precarious potential for large epidemics. Recent outbreaks of YF in Kenya (1992-1993) and Sudan (2003 and 2005) are important because each of these outbreaks have involved the re-emergence of a YFV genotype (East Africa) that remained undetected for nearly 40 years and was previously unconfirmed in a clinically apparent outbreak. In addition, unlike West Africa and South America, YF has yet to emerge in urban areas of East Africa and be vectored by Aedes (Stegomyia) aegypti. This is a significant public health concern in a region where the majority of the population remains unvaccinated. This review describes historical findings, highlights a number of disease indicators, and provides clarification regarding the natural history, recent emergence and future risk of YF in East Africa. Copyright (c) 2008 John Wiley & Sons, Ltd.

  19. International risk of yellow fever spread from the ongoing outbreak in Brazil, December 2016 to May 2017

    PubMed Central

    Dorigatti, Ilaria; Hamlet, Arran; Aguas, Ricardo; Cattarino, Lorenzo; Cori, Anne; Donnelly, Christl A; Garske, Tini; Imai, Natsuko; Ferguson, Neil M

    2017-01-01

    States in south-eastern Brazil were recently affected by the largest Yellow Fever (YF) outbreak seen in a decade in Latin America. Here we provide a quantitative assessment of the risk of travel-related international spread of YF indicating that the United States, Argentina, Uruguay, Spain, Italy and Germany may have received at least one travel-related YF case capable of seeding local transmission. Mitigating the risk of imported YF cases seeding local transmission requires heightened surveillance globally. PMID:28749337

  20. Antibody response to 17D yellow fever vaccine in Ghanaian infants.

    PubMed Central

    Osei-Kwasi, M.; Dunyo, S. K.; Koram, K. A.; Afari, E. A.; Odoom, J. K.; Nkrumah, F. K.

    2001-01-01

    OBJECTIVES: To assess the seroresponses to yellow fever vaccination at 6 and 9 months of age; assess any possible adverse effects of immunization with the 17D yellow fever vaccine in infants, particularly at 6 months of age. METHODS: Four hundred and twenty infants who had completed BCG, OPV and DPT immunizations were randomized to receive yellow fever immunization at either 6 or 9 months. A single dose of 0.5 ml of the reconstituted vaccine was administered to each infant by subcutaneous injection. To determine the yellow fever antibody levels of the infants, each donated 1 ml whole blood prior to immunization and 3 months post-immunization. Each serum sample was titred on Vero cells against the vaccine virus. FINDINGS: The most common adverse reactions reported were fever, cough, diarrhoea and mild reactions at the inoculation site. The incidences of adverse reactions were not statistically different in both groups. None of the pre-immunization sera in both age groups had detectable yellow fever antibodies. Infants immunized at 6 months recorded seroconversion of 98.6% and those immunized at 9 months recorded 98% seroconversion. The GMT of their antibodies were 158.5 and 129.8, respectively. CONCLUSIONS: The results indicate that seroresponses to yellow fever immunization at 6 and 9 months as determined by seroconversion and GMTs of antibodies are similar. The findings of good seroresponses at 6 months without significant adverse effects would suggest that the 17D yellow fever vaccine could be recommended for use in children at 6 months in outbreak situations or in high risk endemic areas. PMID:11731813

  1. International risk of yellow fever spread from the ongoing outbreak in Brazil, December 2016 to May 2017.

    PubMed

    Dorigatti, Ilaria; Hamlet, Arran; Aguas, Ricardo; Cattarino, Lorenzo; Cori, Anne; Donnelly, Christl A; Garske, Tini; Imai, Natsuko; Ferguson, Neil M

    2017-07-13

    States in south-eastern Brazil were recently affected by the largest Yellow Fever (YF) outbreak seen in a decade in Latin America. Here we provide a quantitative assessment of the risk of travel-related international spread of YF indicating that the United States, Argentina, Uruguay, Spain, Italy and Germany may have received at least one travel-related YF case capable of seeding local transmission. Mitigating the risk of imported YF cases seeding local transmission requires heightened surveillance globally. This article is copyright of The Authors, 2017.

  2. Epidemic yellow fever in Borno State of Nigeria: characterisation of hospitalised patients.

    PubMed

    Ekenna, O; Chikwem, J O; Mohammed, I; Durojaiye, S O

    2010-01-01

    In 1990, an outbreak of a febrile illness with high mortality was reported in border villages, later spreading to other areas of Borno State of Nigeria. To present a report of the investigation of that outbreak, with emphasis on the characterisation of hospitalised patients. Selected centres reporting cases of acute febrile illness during the months of August to December, 1990 were visited, to establish surveillance. Case investigation forms were used to obtain clinical and demographic data; and blood samples were obtained from patients for analyses. Only hospitalised patients with adequate clinical information from three centres were included in the analysis. The outbreak, which involved five of the six health zones in the state, and spread into adjoining Gongola state and the Cameroun Republic, was caused by the yellow fever virus. Fever, central nervous system (CNS) involvement, jaundice and haemorrhage were the most common clinical manifestations of 102 hospitalised patients. Eighty -three (81%) of hospitalised patients died and most within two days of admission. CNS manifestations were more common in dying patients than in survivors. The reasons for this rare outbreak of yellow fever in the dry Savannah belt of Borno State remain unclear. Improved surveillance and more effective prevention strategies are needed to avert the recurrence of such outbreaks.

  3. Yellow fever risk assessment in the Central African Republic.

    PubMed

    Ramos Junior, Alberto Novaes; Heukelbach, Jorg

    2015-04-01

    Yellow fever still causes high burden in several areas of sub-Saharan Africa and Latin America. There are few well-designed epidemiological studies and limited data about yellow fever in Africa. Staples et al., in a recently published paper in Transactions of the Royal Society of Tropical Medicine & Hygiene, performed a nationwide study in the Central African Republic (CAR) assessing infection risk and the operational impact of preventive measures. The rapid assessment of human, non-human and mosquito data call attention to the potential risk of future yellow fever outbreaks in the CAR and elsewhere. The study reinforces the need for intensified applied and operational research to address problems and human capacity needs in the realm of neglected tropical diseases in the post-2015 agenda. © The Author 2015. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Facing up to re-emergence of urban yellow fever.

    PubMed

    Monath, T P

    1999-05-08

    Transmitted from person to person by Aedes aegypti, urban yellow fever was eliminated in the first half of this century, with the eradication of its mosquito vector from most of South America. However, reinfestation began in the 1970s is now almost complete, and vector control is considerably more difficult now than before. The threat of urban yellow fever is greatest in towns such as Santa Cruz, Bolivia, near the forest, but improved transport links increase the likelihood of spread by viremic people to nonendemic areas. Van der Stuyft et al. have reported the first instance of urban transmission of yellow fever in the Americas in 44 years. Since residents of the densely populated cities and much visited areas in coastal South America have never been vaccinated, an outbreak there would facilitate widespread dissemination of the disease, even to other continents. While urban yellow fever is a significant threat, carrying a case-fatality rate of about 20%, the constrained dynamics of transmission, early recognition of the striking clinical presentation, and efforts to control the infection should limit the impact of the disease. Laboratory-based surveillance, together with the prevention and control strategies outlined by van der Stuyft et al. are the key defensive measures against the future threat of urban epidemics.

  5. Assessing the risk of international spread of yellow fever virus: a mathematical analysis of an urban outbreak in Asuncion, 2008.

    PubMed

    Johansson, Michael A; Arana-Vizcarrondo, Neysarí; Biggerstaff, Brad J; Gallagher, Nancy; Marano, Nina; Staples, J Erin

    2012-02-01

    Yellow fever virus (YFV), a mosquito-borne virus endemic to tropical Africa and South America, is capable of causing large urban outbreaks of human disease. With the ease of international travel, urban outbreaks could lead to the rapid spread and subsequent transmission of YFV in distant locations. We designed a stochastic metapopulation model with spatiotemporally explicit transmissibility scenarios to simulate the global spread of YFV from a single urban outbreak by infected airline travelers. In simulations of a 2008 outbreak in Asunción, Paraguay, local outbreaks occurred in 12.8% of simulations and international spread in 2.0%. Using simple probabilistic models, we found that local incidence, travel rates, and basic transmission parameters are sufficient to assess the probability of introduction and autochthonous transmission events. These models could be used to assess the risk of YFV spread during an urban outbreak and identify locations at risk for YFV introduction and subsequent autochthonous transmission.

  6. Genomic and structural features of the yellow fever virus from the 2016-2017 Brazilian outbreak.

    PubMed

    Gómez, Mariela Martínez; Abreu, Filipe Vieira Santos de; Santos, Alexandre Araujo Cunha Dos; Mello, Iasmim Silva de; Santos, Marta Pereira; Ribeiro, Ieda Pereira; Ferreira-de-Brito, Anielly; Miranda, Rafaella Moraes de; Castro, Marcia Gonçalves de; Ribeiro, Mario Sergio; Laterrière Junior, Roberto da Costa; Aguiar, Shirlei Ferreira; Meira, Guilherme Louzada Silva; Antunes, Deborah; Torres, Pedro Henrique Monteiro; Mir, Daiana; Vicente, Ana Carolina Paulo; Guimarães, Ana Carolina Ramos; Caffarena, Ernesto Raul; Bello, Gonzalo; Lourenço-de-Oliveira, Ricardo; Bonaldo, Myrna Cristina

    2018-04-01

    Southeastern Brazil has been suffering a rapid expansion of a severe sylvatic yellow fever virus (YFV) outbreak since late 2016, which has reached one of the most populated zones in Brazil and South America, heretofore a yellow fever-free zone for more than 70 years. In the current study, we describe the complete genome of 12 YFV samples from mosquitoes, humans and non-human primates from the Brazilian 2017 epidemic. All of the YFV sequences belong to the modern lineage (sub-lineage 1E) of South American genotype I, having been circulating for several months prior to the December 2016 detection. Our data confirm that viral strains associated with the most severe YF epidemic in South America in the last 70 years display unique amino acid substitutions that are mainly located in highly conserved positions in non-structural proteins. Our data also corroborate that YFV has spread southward into Rio de Janeiro state following two main sylvatic dispersion routes that converged at the border of the great metropolitan area comprising nearly 12 million unvaccinated inhabitants. Our original results can help public health authorities to guide the surveillance, prophylaxis and control measures required to face such a severe epidemiological problem. Finally, it will also inspire other workers to further investigate the epidemiological and biological significance of the amino acid polymorphisms detected in the Brazilian 2017 YFV strains.

  7. Live Attenuated Yellow Fever 17D Vaccine: A Legacy Vaccine Still Controlling Outbreaks In Modern Day.

    PubMed

    Collins, Natalie D; Barrett, Alan D T

    2017-03-01

    Live attenuated 17D vaccine is considered one of the safest and efficacious vaccines developed to date. This review highlights what is known and the gaps in knowledge of vaccine-induced protective immunity. Recently, the World Health Organization modifying its guidance from 10-year booster doses to one dose gives lifelong protection in most populations. Nonetheless, there are some data suggesting immunity, though protective, may wane over time in certain populations and more research is needed to address this question. Despite having an effective vaccine to control yellow fever, vaccine shortages were identified during outbreaks in 2016, eventuating the use of a fractional-dosing campaign in the Democratic Republic of the Congo. Limited studies hinder identification of the underlying mechanism(s) of vaccine longevity; however, concurrent outbreaks during 2016 provide an opportunity to evaluate vaccine immunity following fractional dosing and insights into vaccine longevity in populations where there is limited information.

  8. Yellow fever: an update.

    PubMed

    Monath, T P

    2001-08-01

    Yellow fever, the original viral haemorrhagic fever, was one of the most feared lethal diseases before the development of an effective vaccine. Today the disease still affects as many as 200,000 persons annually in tropical regions of Africa and South America, and poses a significant hazard to unvaccinated travellers to these areas. Yellow fever is transmitted in a cycle involving monkeys and mosquitoes, but human beings can also serve as the viraemic host for mosquito infection. Recent increases in the density and distribution of the urban mosquito vector, Aedes aegypti, as well as the rise in air travel increase the risk of introduction and spread of yellow fever to North and Central America, the Caribbean and Asia. Here I review the clinical features of the disease, its pathogenesis and pathophysiology. The disease mechanisms are poorly understood and have not been the subject of modern clinical research. Since there is no specific treatment, and management of patients with the disease is extremely problematic, the emphasis is on preventative vaccination. As a zoonosis, yellow fever cannot be eradicated, but reduction of the human disease burden is achievable through routine childhood vaccination in endemic countries, with a low cost for the benefits obtained. The biological characteristics, safety, and efficacy of live attenuated, yellow fever 17D vaccine are reviewed. New applications of yellow fever 17D virus as a vector for foreign genes hold considerable promise as a means of developing new vaccines against other viruses, and possibly against cancers.

  9. [Yellow fever: reemerging in the state of Sao Paulo, Brazil, 2009].

    PubMed

    Mascheretti, Melissa; Tengan, Ciléa H; Sato, Helena Keiko; Suzuki, Akemi; de Souza, Renato Pereira; Maeda, Marina; Brasil, Roosecelis; Pereira, Mariza; Tubaki, Rosa Maria; Wanderley, Dalva M V; Fortaleza, Carlos Magno Castelo Branco; Ribeiro, Ana Freitas

    2013-10-01

    To describe the investigation of a sylvatic yellow fever outbreak in the state of Sao Paulo and the main control measures undertaken. This is a descriptive study of a sylvatic yellow fever outbreak in the Southwestern region of the state from February to April 2009. Suspected and confirmed cases in humans and in non-human primates were evaluated. Entomological investigation in sylvatic environment involved capture at ground level and in the tree canopy to identify species and detect natural infections. Control measures were performed in urban areas to control Aedes aegypti . Vaccination was directed at residents living in areas with confirmed viral circulation and also at nearby cities according to national recommendation. Twenty-eight human cases were confirmed (39.3% case fatality rate) in rural areas of Sarutaiá, Piraju, Tejupá, Avaré and Buri. The deaths of 56 non-human primates were also reported, 91.4% were Allouatta sp. Epizootics was confirmed in two non-human primates in the cities of Itapetininga and Buri. A total of 1,782 mosquitoes were collected, including Haemagogus leucocelaenus , Hg. janthinomys/capricornii , and Sabethes chloropterus, Sa. purpureus and Sa. undosus . Yellow fever virus was isolated from a group of Hg. Leucocelaenus from Buri. Vaccination was carried out in 49 cities, with a total of 1,018,705 doses. Nine serious post-vaccination adverse events were reported. The cases occurred between February and April 2009 in areas with no recorded yellow fever virus circulation in over 60 years. The outbreak region occurred outside the original recommended vaccination area with a high percentage of susceptible population. The fast adoption of control measures interrupted the human transmission within a month and the confirmation of viral circulation in humans, monkeys and mosquitoes. The results allowed the identification of new areas of viral circulation but further studies are required to clarify the dynamics of the spread of this disease.

  10. Existing and potential infection risk zones of yellow fever worldwide: a modelling analysis.

    PubMed

    Shearer, Freya M; Longbottom, Joshua; Browne, Annie J; Pigott, David M; Brady, Oliver J; Kraemer, Moritz U G; Marinho, Fatima; Yactayo, Sergio; de Araújo, Valdelaine E M; da Nóbrega, Aglaêr A; Fullman, Nancy; Ray, Sarah E; Mosser, Jonathan F; Stanaway, Jeffrey D; Lim, Stephen S; Reiner, Robert C; Moyes, Catherine L; Hay, Simon I; Golding, Nick

    2018-03-01

    Yellow fever cases are under-reported and the exact distribution of the disease is unknown. An effective vaccine is available but more information is needed about which populations within risk zones should be targeted to implement interventions. Substantial outbreaks of yellow fever in Angola, Democratic Republic of the Congo, and Brazil, coupled with the global expansion of the range of its main urban vector, Aedes aegypti, suggest that yellow fever has the propensity to spread further internationally. The aim of this study was to estimate the disease's contemporary distribution and potential for spread into new areas to help inform optimal control and prevention strategies. We assembled 1155 geographical records of yellow fever virus infection in people from 1970 to 2016. We used a Poisson point process boosted regression tree model that explicitly incorporated environmental and biological explanatory covariates, vaccination coverage, and spatial variability in disease reporting rates to predict the relative risk of apparent yellow fever virus infection at a 5 × 5 km resolution across all risk zones (47 countries across the Americas and Africa). We also used the fitted model to predict the receptivity of areas outside at-risk zones to the introduction or reintroduction of yellow fever transmission. By use of previously published estimates of annual national case numbers, we used the model to map subnational variation in incidence of yellow fever across at-risk countries and to estimate the number of cases averted by vaccination worldwide. Substantial international and subnational spatial variation exists in relative risk and incidence of yellow fever as well as varied success of vaccination in reducing incidence in several high-risk regions, including Brazil, Cameroon, and Togo. Areas with the highest predicted average annual case numbers include large parts of Nigeria, the Democratic Republic of the Congo, and South Sudan, where vaccination coverage in 2016

  11. Assessing the Risk of International Spread of Yellow Fever Virus: A Mathematical Analysis of an Urban Outbreak in Asunción, 2008

    PubMed Central

    Johansson, Michael A.; Arana-Vizcarrondo, Neysarí; Biggerstaff, Brad J.; Gallagher, Nancy; Marano, Nina; Staples, J. Erin

    2012-01-01

    Yellow fever virus (YFV), a mosquito-borne virus endemic to tropical Africa and South America, is capable of causing large urban outbreaks of human disease. With the ease of international travel, urban outbreaks could lead to the rapid spread and subsequent transmission of YFV in distant locations. We designed a stochastic metapopulation model with spatiotemporally explicit transmissibility scenarios to simulate the global spread of YFV from a single urban outbreak by infected airline travelers. In simulations of a 2008 outbreak in Asunción, Paraguay, local outbreaks occurred in 12.8% of simulations and international spread in 2.0%. Using simple probabilistic models, we found that local incidence, travel rates, and basic transmission parameters are sufficient to assess the probability of introduction and autochthonous transmission events. These models could be used to assess the risk of YFV spread during an urban outbreak and identify locations at risk for YFV introduction and subsequent autochthonous transmission. PMID:22302873

  12. Geographic patterns and environmental factors associated with human yellow fever presence in the Americas

    PubMed Central

    Aldighieri, Sylvain; Machado, Gustavo; Leonel, Deise Galan; Vilca, Luz Maria; Uriona, Sonia; Schneider, Maria Cristina

    2017-01-01

    Background In the Americas, yellow fever virus transmission is a latent threat due to the proximity between urban and wild environments. Although yellow fever has nearly vanished from North and Central America, there are still 13 countries in the Americas considered endemic by the World Health Organization. Human cases usually occur as a result of the exposure to sylvatic yellow fever in tropical forested environments; but urban outbreaks reported during the last decade demonstrate that the risk in this environment still exists. The objective of this study was to identify spatial patterns and the relationship between key geographic and environmental factors with the distribution of yellow fever human cases in the Americas. Methodology/Principal findings An ecological study was carried out to analyze yellow fever human cases reported to the Pan American Health Organization from 2000 to 2014, aggregated by second administrative level subdivisions (counties). Presence of yellow fever by county was used as the outcome variable and eight geo-environmental factors were used as independent variables. Spatial analysis was performed to identify and examine natural settings per county. Subsequently, a multivariable logistic regression model was built. During the study period, 1,164 cases were reported in eight out of the 13 endemic countries. Nearly 83.8% of these cases were concentrated in three countries: Peru (37.4%), Brazil (28.1%) and Colombia (18.4%); and distributed in 57 states/provinces, specifically in 286 counties (3.4% of total counties). Yellow fever presence was significantly associated with altitude, rain, diversity of non-human primate hosts and temperature. A positive spatial autocorrelation revealed a clustered geographic pattern in 138/286 yellow fever positive counties (48.3%). Conclusions/Significance A clustered geographic pattern of yellow fever was identified mostly along the Andes eastern foothills. This risk map could support health policies in

  13. Geographic patterns and environmental factors associated with human yellow fever presence in the Americas.

    PubMed

    Hamrick, Patricia Najera; Aldighieri, Sylvain; Machado, Gustavo; Leonel, Deise Galan; Vilca, Luz Maria; Uriona, Sonia; Schneider, Maria Cristina

    2017-09-01

    In the Americas, yellow fever virus transmission is a latent threat due to the proximity between urban and wild environments. Although yellow fever has nearly vanished from North and Central America, there are still 13 countries in the Americas considered endemic by the World Health Organization. Human cases usually occur as a result of the exposure to sylvatic yellow fever in tropical forested environments; but urban outbreaks reported during the last decade demonstrate that the risk in this environment still exists. The objective of this study was to identify spatial patterns and the relationship between key geographic and environmental factors with the distribution of yellow fever human cases in the Americas. An ecological study was carried out to analyze yellow fever human cases reported to the Pan American Health Organization from 2000 to 2014, aggregated by second administrative level subdivisions (counties). Presence of yellow fever by county was used as the outcome variable and eight geo-environmental factors were used as independent variables. Spatial analysis was performed to identify and examine natural settings per county. Subsequently, a multivariable logistic regression model was built. During the study period, 1,164 cases were reported in eight out of the 13 endemic countries. Nearly 83.8% of these cases were concentrated in three countries: Peru (37.4%), Brazil (28.1%) and Colombia (18.4%); and distributed in 57 states/provinces, specifically in 286 counties (3.4% of total counties). Yellow fever presence was significantly associated with altitude, rain, diversity of non-human primate hosts and temperature. A positive spatial autocorrelation revealed a clustered geographic pattern in 138/286 yellow fever positive counties (48.3%). A clustered geographic pattern of yellow fever was identified mostly along the Andes eastern foothills. This risk map could support health policies in endemic countries. Geo-environmental factors associated with presence

  14. Vaccinating in disease-free regions: a vaccine model with application to yellow fever.

    PubMed

    Codeço, Claudia T; Luz, Paula M; Coelho, Flavio; Galvani, Alison P; Struchiner, Claudio

    2007-12-22

    Concerns regarding natural or induced emergence of infectious diseases have raised a debate on the pros and cons of pre-emptive vaccination of populations under uncertain risk. In the absence of immediate risk, ethical issues arise because even smaller risks associated with the vaccine are greater than the immediate disease risk (which is zero). The model proposed here seeks to formalize the vaccination decision process looking from the perspective of the susceptible individual, and results are shown in the context of the emergence of urban yellow fever in Brazil. The model decomposes the individual's choice about vaccinating or not into uncertain components. The choice is modelled as a function of (i) the risk of a vaccine adverse event, (ii) the risk of an outbreak and (iii) the probability of receiving the vaccine or escaping serious disease given an outbreak. Additionally, we explore how this decision varies as a function of mass vaccination strategies of varying efficiency. If disease is considered possible but unlikely (risk of outbreak less than 0.1), delay vaccination is a good strategy if a reasonably efficient campaign is expected. The advantage of waiting increases as the rate of transmission is reduced (low R0) suggesting that vector control programmes and emergency vaccination preparedness work together to favour this strategy. The opposing strategy, vaccinating pre-emptively, is favoured if the probability of yellow fever urbanization is high or if expected R0 is high and emergency action is expected to be slow. In summary, our model highlights the nonlinear dependence of an individual's best strategy on the preparedness of a response to a yellow fever outbreak or other emergent infectious disease.

  15. Evidence for multiple sylvatic transmission cycles during the 2016-2017 yellow fever virus outbreak, Brazil.

    PubMed

    Moreira-Soto, A; Torres, M C; Lima de Mendonça, M C; Mares-Guia, M A; Dos Santos Rodrigues, C D; Fabri, A A; Dos Santos, C C; Machado Araújo, E S; Fischer, C; Ribeiro Nogueira, R M; Drosten, C; Sequeira, P Carvalho; Drexler, J F; Bispo de Filippis, A M

    2018-02-07

    Since December 2016, Brazil has experienced an unusually large outbreak of yellow fever (YF). Whether urban transmission may contribute to the extent of the outbreak is unclear. The objective of this study was to characterize YF virus (YFV) genomes and to identify spatial patterns to determine the distribution and origin of YF cases in Minas Gerais, Espírito Santo and Rio de Janeiro, the most affected Brazilian states during the current YFV outbreak. We characterized near-complete YFV genomes from 14 human cases and two nonhuman primates (NHP), sampled from February to April 2017, retrieved epidemiologic data of cases and used a geographic information system to investigate the geospatial spread of YFV. All YFV strains were closely related. On the basis of signature mutations, we identified two cocirculating YFV clusters. One was restricted to the hinterland of Espírito Santo state, and another formed a coastal cluster encompassing several hundred kilometers. Both clusters comprised strains from humans living in rural areas and NHP. Another NHP lineage clustered in a basal relationship. No signs of adaptation of YFV strains to human hosts were detected. Our data suggest sylvatic transmission during the current outbreak. Additionally, cocirculation of two distinct YFV clades occurring in humans and NHP suggests the existence of multiple sylvatic transmission cycles. Increased detection of YFV might be facilitated by raised awareness for arbovirus-mediated disease after Zika and chikungunya virus outbreaks. Further surveillance is required, as reemergence of YFV from NHPs might continue and facilitate the appearance of urban transmission cycles. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. Intrathecal antibody production in two cases of yellow fever vaccine associated neurotropic disease in Argentina.

    PubMed

    Pires-Marczeski, Fanny Clara; Martinez, Valeria Paula; Nemirovsky, Corina; Padula, Paula Julieta

    2011-12-01

    During the period 2007-2008 several epizootics of Yellow fever with dead of monkeys occurred in southeastern Brasil, Paraguay, and northeastern Argentina. In 2008 after a Yellow fever outbreak an exhaustive prevention campaign took place in Argentina using 17D live attenuated Yellow fever vaccine. This vaccine is considered one of the safest live virus vaccines, although serious adverse reactions may occur after vaccination, and vaccine-associated neurotropic disease are reported rarely. The aim of this study was to confirm two serious adverse events associated to Yellow fever vaccine in Argentina, and to describe the analysis performed to assess the origin of specific IgM against Yellow fever virus (YFV) in cerebrospinal fluid (CSF). Both cases coincided with the Yellow fever vaccine-associated neurotropic disease case definition, being clinical diagnosis longitudinal myelitis (case 1) and meningoencephalitis (case 2). Specific YFV antibodies were detected in CSF and serum samples in both cases by IgM antibody-capture ELISA. No other cause of neurological disease was identified. In order to obtain a conclusive diagnosis of central nervous system (CNS) infection the IgM antibody index (AI(IgM) ) was calculated. High AI(IgM) values were found in both cases indicating intrathecal production of antibodies and, therefore, CNS post-vaccinal YFV infection could be definitively associated to YFV vaccination. Copyright © 2011 Wiley Periodicals, Inc.

  17. Yellow fever virus in Haemagogus leucocelaenus and Aedes serratus mosquitoes, southern Brazil, 2008.

    PubMed

    Cardoso, Jader da C; de Almeida, Marco A B; dos Santos, Edmilson; da Fonseca, Daltro F; Sallum, Maria A M; Noll, Carlos A; Monteiro, Hamilton A de O; Cruz, Ana C R; Carvalho, Valeria L; Pinto, Eliana V; Castro, Francisco C; Nunes Neto, Joaquim P; Segura, Maria N O; Vasconcelos, Pedro F C

    2010-12-01

    Yellow fever virus (YFV) was isolated from Haemagogus leucocelaenus mosquitoes during an epizootic in 2001 in the Rio Grande do Sul State in southern Brazil. In October 2008, a yellow fever outbreak was reported there, with nonhuman primate deaths and human cases. This latter outbreak led to intensification of surveillance measures for early detection of YFV and support for vaccination programs. We report entomologic surveillance in 2 municipalities that recorded nonhuman primate deaths. Mosquitoes were collected at ground level, identified, and processed for virus isolation and molecular analyses. Eight YFV strains were isolated (7 from pools of Hg. leucocelaenus mosquitoes and another from Aedes serratus mosquitoes); 6 were sequenced, and they grouped in the YFV South American genotype I. The results confirmed the role of Hg. leucocelaenus mosquitoes as the main YFV vector in southern Brazil and suggest that Ae. serratus mosquitoes may have a potential role as a secondary vector.

  18. 17DD yellow fever vaccine

    PubMed Central

    Martins, Reinaldo M.; Maia, Maria de Lourdes S.; Farias, Roberto Henrique G.; Camacho, Luiz Antonio B.; Freire, Marcos S.; Galler, Ricardo; Yamamura, Anna Maya Yoshida; Almeida, Luiz Fernando C.; Lima, Sheila Maria B.; Nogueira, Rita Maria R.; Sá, Gloria Regina S.; Hokama, Darcy A.; de Carvalho, Ricardo; Freire, Ricardo Aguiar V.; Filho, Edson Pereira; Leal, Maria da Luz Fernandes; Homma, Akira

    2013-01-01

    Objective: To verify if the Bio-Manguinhos 17DD yellow fever vaccine (17DD-YFV) used in lower doses is as immunogenic and safe as the current formulation. Results: Doses from 27,476 IU to 587 IU induced similar seroconversion rates and neutralizing antibodies geometric mean titers (GMTs). Immunity of those who seroconverted to YF was maintained for 10 mo. Reactogenicity was low for all groups. Methods: Young and healthy adult males (n = 900) were recruited and randomized into 6 groups, to receive de-escalating doses of 17DD-YFV, from 27,476 IU to 31 IU. Blood samples were collected before vaccination (for neutralization tests to yellow fever, serology for dengue and clinical chemistry), 3 to 7 d after vaccination (for viremia and clinical chemistry) and 30 d after vaccination (for new yellow fever serology and clinical chemistry). Adverse events diaries were filled out by volunteers during 10 d after vaccination. Volunteers were retested for yellow fever and dengue antibodies 10 mo later. Seropositivity for dengue was found in 87.6% of volunteers before vaccination, but this had no significant influence on conclusions. Conclusion: In young healthy adults Bio-Manguinhos/Fiocruz yellow fever vaccine can be used in much lower doses than usual. International Register ISRCTN 38082350. PMID:23364472

  19. A public health risk assessment for yellow fever vaccination: a model exemplified by an outbreak in the state of São Paulo, Brazil.

    PubMed

    Ribeiro, Ana Freitas; Tengan, Ciléa; Sato, Helena Keico; Spinola, Roberta; Mascheretti, Melissa; França, Ana Cecilia Costa; Port-Carvalho, Marcio; Pereira, Mariza; Souza, Renato Pereira de; Amaku, Marcos; Burattini, Marcelo Nascimento; Coutinho, Francisco Antonio Bezerra; Lopez, Luis Fernandez; Massad, Eduardo

    2015-04-01

    We propose a method to analyse the 2009 outbreak in the region of Botucatu in the state of São Paulo (SP), Brazil, when 28 yellow fever (YF) cases were confirmed, including 11 deaths. At the time of the outbreak, the Secretary of Health of the State of São Paulo vaccinated one million people, causing the death of five individuals, an unprecedented number of YF vaccine-induced fatalities. We apply a mathematical model described previously to optimise the proportion of people who should be vaccinated to minimise the total number of deaths. The model was used to calculate the optimum proportion that should be vaccinated in the remaining, vaccine-free regions of SP, considering the risk of vaccine-induced fatalities and the risk of YF outbreaks in these regions.

  20. Yellow Fever Virus in Haemagogus leucocelaenus and Aedes serratus Mosquitoes, Southern Brazil, 2008

    PubMed Central

    Cardoso, Jáder da C.; de Almeida, Marco A.B.; dos Santos, Edmilson; da Fonseca, Daltro F.; Sallum, Maria A.M.; Noll, Carlos A.; Monteiro, Hamilton A. de O.; Cruz, Ana C.R.; Carvalho, Valéria L.; Pinto, Eliana V.; Castro, Francisco C.; Neto, Joaquim P. Nunes; Segura, Maria N.O.

    2010-01-01

    Yellow fever virus (YFV) was isolated from Haemagogus leucocelaenus mosquitoes during an epizootic in 2001 in the Rio Grande do Sul State in southern Brazil. In October 2008, a yellow fever outbreak was reported there, with nonhuman primate deaths and human cases. This latter outbreak led to intensification of surveillance measures for early detection of YFV and support for vaccination programs. We report entomologic surveillance in 2 municipalities that recorded nonhuman primate deaths. Mosquitoes were collected at ground level, identified, and processed for virus isolation and molecular analyses. Eight YFV strains were isolated (7 from pools of Hg. leucocelaenus mosquitoes and another from Aedes serratus mosquitoes); 6 were sequenced, and they grouped in the YFV South American genotype I. The results confirmed the role of Hg. leucocelaenus mosquitoes as the main YFV vector in southern Brazil and suggest that Ae. serratus mosquitoes may have a potential role as a secondary vector. PMID:21122222

  1. Using Local History To Understand National Themes: The Yellow Fever Epidemic in Philadelphia in 1793.

    ERIC Educational Resources Information Center

    Westbury, Susan

    2003-01-01

    Provides background information for a local history project about the 1793 Philadelphia (Pennsylvania) yellow fever outbreak. Offers potential project topics to help students learn about local history and understand life in the eighteenth century United States. (CMK)

  2. Viscerotropic disease following yellow fever vaccination in Peru.

    PubMed

    Whittembury, Alvaro; Ramirez, Gladys; Hernández, Herminio; Ropero, Alba Maria; Waterman, Steve; Ticona, María; Brinton, Margo; Uchuya, Jorge; Gershman, Mark; Toledo, Washington; Staples, Erin; Campos, Clarense; Martínez, Mario; Chang, Gwong-Jen J; Cabezas, Cesar; Lanciotti, Robert; Zaki, Sherif; Montgomery, Joel M; Monath, Thomas; Hayes, Edward

    2009-10-09

    Five suspected cases of yellow fever vaccine-associated viscerotropic disease (YEL-AVD) clustered in space and time following a vaccination campaign in Ica, Peru in 2007. All five people received the same lot of 17DD live attenuated yellow fever vaccine before their illness; four of the five died of confirmed YEL-AVD. The surviving case was classified as probable YEL-AVD. Intensive investigation yielded no abnormalities of the implicated vaccine lot and no common risk factors. This is the first described space-time cluster of yellow fever viscerotropic disease involving more than two cases. Mass yellow fever vaccination should be avoided in areas that present extremely low risk of yellow fever.

  3. Yellow fever: the recurring plague.

    PubMed

    Tomori, Oyewale

    2004-01-01

    Despite the availability of a safe and efficacious vaccine, yellow fever (YF) remains a disease of significant public health importance, with an estimated 200,000 cases and 30,000 deaths annually. The disease is endemic in tropical regions of Africa and South America; nearly 90% of YF cases and deaths occur in Africa. It is a significant hazard to unvaccinated travelers to these endemic areas. Virus transmission occurs between humans, mosquitoes, and monkeys. The mosquito, the true reservoir of YF, is infected throughout its life, and can transmit the virus transovarially through infected eggs. Man and monkeys, on the other hand, play the role of temporary amplifiers of the virus available for mosquito infection. Recent increases in the density and distribution of the urban mosquito vector, Aedes aegypti, as well as the rise in air travel increase the risk of introduction and spread of yellow fever to North and Central America, the Caribbean, the Middle East, Asia, Australia, and Oceania. It is an acute infectious disease characterized by sudden onset with a two-phase development, separated by a short period of remission. The clinical spectrum of yellow fever varies from very mild, nonspecific, febrile illness to a fulminating, sometimes fatal disease with pathognomic features. In severe cases, jaundice, bleeding diathesis, with hepatorenal involvement are common. The case fatality rate of severe yellow fever is 50% or higher. The pathogenesis and pathophysiology of the disease are poorly understood and have not been the subject of modern clinical research. There is no specific treatment for YF, making the management of YF patients extremely problematic. YF is a zoonotic disease that cannot be eradicated, therefore instituting preventive vaccination through routine childhood vaccination in endemic countries, can significantly reduce the burden of the disease. The distinctive properties of lifelong immunity after a single dose of yellow fever vaccination are the

  4. Yellow fever vaccination coverage following massive emergency immunization campaigns in rural Uganda, May 2011: a community cluster survey.

    PubMed

    Bagonza, James; Rutebemberwa, Elizeus; Mugaga, Malimbo; Tumuhamye, Nathan; Makumbi, Issa

    2013-03-07

    Following an outbreak of yellow fever in northern Uganda in December 2010, Ministry of Health conducted a massive emergency vaccination campaign in January 2011. The reported vaccination coverage in Pader District was 75.9%. Administrative coverage though timely, is affected by incorrect population estimates and over or under reporting of vaccination doses administered. This paper presents the validated yellow fever vaccination coverage following massive emergency immunization campaigns in Pader district. A cross sectional cluster survey was carried out in May 2011 among communities in Pader district and 680 respondents were indentified using the modified World Health Organization (WHO) 40 × 17 cluster survey sampling methodology. Respondents were aged nine months and above. Interviewer administered questionnaires were used to collect data on demographic characteristics, vaccination status and reasons for none vaccination. Vaccination status was assessed using self reports and vaccination card evidence. Our main outcomes were measures of yellow fever vaccination coverage in each age-specific stratum, overall, and disaggregated by age and sex, adjusting for the clustered design and the size of the population in each stratum. Of the 680 survey respondents, 654 (96.1%, 95% CI 94.9 - 97.8) reported being vaccinated during the last campaign but only 353 (51.6%, 95% CI 47.2 - 56.1) had valid yellow fever vaccination cards. Of the 280 children below 5 years, 269 (96.1%, 95% CI 93.7 - 98.7) were vaccinated and nearly all males 299 (96.9%, 95% CI 94.3 - 99.5) were vaccinated. The main reasons for none vaccination were; having travelled out of Pader district during the campaign period (40.0%), lack of transport to immunization posts (28.0%) and, sickness at the time of vaccination (16.0%). Our results show that actual yellow fever vaccination coverage was high and satisfactory in Pader district since it was above the desired minimum threshold coverage of 80% according

  5. Yellow fever vaccination coverage following massive emergency immunization campaigns in rural Uganda, May 2011: a community cluster survey

    PubMed Central

    2013-01-01

    Background Following an outbreak of yellow fever in northern Uganda in December 2010, Ministry of Health conducted a massive emergency vaccination campaign in January 2011. The reported vaccination coverage in Pader District was 75.9%. Administrative coverage though timely, is affected by incorrect population estimates and over or under reporting of vaccination doses administered. This paper presents the validated yellow fever vaccination coverage following massive emergency immunization campaigns in Pader district. Methods A cross sectional cluster survey was carried out in May 2011 among communities in Pader district and 680 respondents were indentified using the modified World Health Organization (WHO) 40 × 17 cluster survey sampling methodology. Respondents were aged nine months and above. Interviewer administered questionnaires were used to collect data on demographic characteristics, vaccination status and reasons for none vaccination. Vaccination status was assessed using self reports and vaccination card evidence. Our main outcomes were measures of yellow fever vaccination coverage in each age-specific stratum, overall, and disaggregated by age and sex, adjusting for the clustered design and the size of the population in each stratum. Results Of the 680 survey respondents, 654 (96.1%, 95% CI 94.9 – 97.8) reported being vaccinated during the last campaign but only 353 (51.6%, 95% CI 47.2 – 56.1) had valid yellow fever vaccination cards. Of the 280 children below 5 years, 269 (96.1%, 95% CI 93.7 – 98.7) were vaccinated and nearly all males 299 (96.9%, 95% CI 94.3 – 99.5) were vaccinated. The main reasons for none vaccination were; having travelled out of Pader district during the campaign period (40.0%), lack of transport to immunization posts (28.0%) and, sickness at the time of vaccination (16.0%). Conclusions Our results show that actual yellow fever vaccination coverage was high and satisfactory in Pader district since it was above the

  6. Rift Valley fever outbreak--Kenya, November 2006-January 2007.

    PubMed

    2007-02-02

    In mid-December 2006, several unexplained fatalities associated with fever and generalized bleeding were reported to the Kenya Ministry of Health (KMOH) from Garissa District in North Eastern Province (NEP). By December 20, a total of 11 deaths had been reported. Of serum samples collected from the first 19 patients, Rift Valley fever (RVF) virus RNA or immunoglobulin M (IgM) antibodies against RVF virus were found in samples from 10 patients; all serum specimens were negative for yellow fever, Ebola, Crimean-Congo hemorrhagic fever, and dengue viruses. The outbreak was confirmed by isolation of RVF virus from six of the specimens. Humans can be infected with RVF virus from bites of mosquitoes or other arthropod vectors that have fed on animals infected with RVF virus, or through contact with viremic animals, particularly livestock. Reports of livestock deaths and unexplained animal abortions in NEP provided further evidence of an RVF outbreak. On December 20, an investigation was launched by KMOH, the Kenya Field Epidemiology and Laboratory Training Program (FELTP), the Kenya Medical Research Institute (KEMRI), the Walter Reed Project of the U.S. Army Medical Research Unit, CDC-Kenya's Global Disease Detection Center, and other partners, including the World Health Organization (WHO) and Médecins Sans Frontières (MSF). This report describes the findings from that initial investigation and the control measures taken in response to the RVF outbreak, which spread to multiple additional provinces and districts, resulting in 404 cases with 118 deaths as of January 25, 2007.

  7. THE TRANSMISSION OF YELLOW FEVER

    PubMed Central

    Davis, Nelson C.

    1930-01-01

    1. Saimiri sciureus has been infected with yellow fever virus, both by the inoculation of infectious blood and by the bites of infective mosquitoes. Some of the monkeys have died, showing lesions, including hepatic necrosis, suggesting yellow fever as seen in human beings and in rhesus monkeys. Virus has been transferred back to M. rhesus from infected Saimiri both by blood inoculation and by mosquito bites. The virus undoubtedly has been maintained through four direct passages in Saimiri. Reinoculations of infectious material into recovered monkeys have not given rise to invasion of the blood stream by virus. Sera from recovered animals have protected M. rhesus against the inoculation of virus. 2. It has been possible to pass the virus to and from Ateleus ater by the injection of blood or liver and by the bites of mosquitoes. The livers from two infected animals have shown no necrosis. The serum from one recovered monkey proved to be protective for M. rhesus. 3. Only three out of twelve Lagothrix lagotricha have reacted to yellow fever virus by a rise in temperature. Probably none have died as a result of the infection. In only one instance has the virus been transferred back to M. rhesus. The sera of recovered animals have had a protective action against yellow fever virus. PMID:19869721

  8. Yellow Fever Vaccine

    MedlinePlus

    ... way to prevent yellow fever is to avoid mosquito bites by:staying in well-screened or air-conditioned areas, wearing clothes that cover most of your body, using an effective insect repellent, such as those containing DEET.

  9. A Possible Connection between the 1878 Yellow Fever Epidemic in the Southern United States and the 1877-78 El Niño Episode.

    NASA Astrophysics Data System (ADS)

    Diaz, Henry F.; McCabe, Gregory J.

    1999-01-01

    One of the most severe outbreaks of yellow fever, a viral disease transmitted by the Aedes aegypti mosquito, affected the southern United States in the summer of 1878. The economic and human toll was enormous, and the city of Memphis, Tennessee, was one of the most affected. The authors suggest that as a consequence of one of the strongest El Niño episodes on record-that which occurred in 1877-78-exceptional climate anomalies occurred in the United States (as well as in many other parts of the world), which may have been partly responsible for the widespread nature and severity of the 1878 yellow fever outbreak.This study documents some of the extreme climate anomalies that were recorded in 1877 and 1878 in parts of the eastern United States, with particular emphasis on highlighting the evolution of these anomalies, as they might have contributed to the epidemic. Other years with major outbreaks of yellow fever in the eighteenth and nineteenth centuries also occurred during the course of El Niño episodes, a fact that appears not to have been noted before in the literature.

  10. International travel between global urban centres vulnerable to yellow fever transmission.

    PubMed

    Brent, Shannon E; Watts, Alexander; Cetron, Martin; German, Matthew; Kraemer, Moritz Ug; Bogoch, Isaac I; Brady, Oliver J; Hay, Simon I; Creatore, Maria I; Khan, Kamran

    2018-05-01

    To examine the potential for international travel to spread yellow fever virus to cities around the world. We obtained data on the international flight itineraries of travellers who departed yellow fever-endemic areas of the world in 2016 for cities either where yellow fever was endemic or which were suitable for viral transmission. Using a global ecological model of dengue virus transmission, we predicted the suitability of cities in non-endemic areas for yellow fever transmission. We obtained information on national entry requirements for yellow fever vaccination at travellers' destination cities. In 2016, 45.2 million international air travellers departed from yellow fever-endemic areas of the world. Of 11.7 million travellers with destinations in 472 cities where yellow fever was not endemic but which were suitable for virus transmission, 7.7 million (65.7%) were not required to provide proof of vaccination upon arrival. Brazil, China, India, Mexico, Peru and the United States of America had the highest volumes of travellers arriving from yellow fever-endemic areas and the largest populations living in cities suitable for yellow fever transmission. Each year millions of travellers depart from yellow fever-endemic areas of the world for cities in non-endemic areas that appear suitable for viral transmission without having to provide proof of vaccination. Rapid global changes in human mobility and urbanization make it vital for countries to re-examine their vaccination policies and practices to prevent urban yellow fever epidemics.

  11. Yellow fever vaccine: an effective vaccine for travelers.

    PubMed

    Verma, Ramesh; Khanna, Pardeep; Chawla, Suraj

    2014-01-01

    Yellow fever (YF) is an acute viral communicable disease transmitted by an arbovirus of the Flavivirus genus. It is primarily a zoonotic disease, especially the monkeys. Worldwide, an estimated 200,000 cases of yellow fever occurred each year, and the case-fatality rate is ~15%. Forty-five endemic countries in Africa and Latin America, with a population of close to 1 billion, are at risk. Up to 50% of severely affected persons from YF die without treatment. During 2009, 55 cases and 18 deaths were reported from Brazil, Colombia, and Peru. Brazil reported the maximum number of cases and death, i.e., 42 cases with 11 deaths. From January 2010 to March 2011, outbreaks of YF were reported to the WHO by Cameroon, Democratic Republic of Congo, Cote d'Ivoire, Guinea, Sierra Leone, Senegal, and Uganda. Cases were also reported in three northern districts of Abim, Agago, and Kitugun near the border with South Sudan. YF usually causes fever, muscle pain with prominent backache, headache, shivers, loss of appetite, and nausea or vomiting. Most patients improve, and their symptoms disappear after 3 to 4 d. Half of the patients who enter the toxic phase die within 10-14 d, while the rest recover without significant organ damage. Vaccination has been the single most important measure for preventing YF. The 17D-204 YF vaccine is a freeze-dried, live attenuated, highly effective vaccine. It is available in single-dose or multi-dose vials and should be stored at 2-8 °C. It is reconstituted with normal saline and should be used within 1 h of reconstitution. The 0.5 mL dose is delivered subcutaneously. Revaccination is recommended every 10 y for people at continued risk of exposure to yellow fever virus (YFV). This vaccine is available worldwide. Travelers, especially to Africa or Latin America from Asia, must have a certificate documenting YF vaccination, which is required by certain countries for entry under the International Health Regulations (IHR) of the WHO.

  12. Late or Lack of Vaccination Linked to Importation of Yellow Fever from Angola to China.

    PubMed

    Song, Rui; Guan, Shengcan; Lee, Shui Shan; Chen, Zhihai; Chen, Chen; Han, Lifen; Xu, Yanli; Li, Ang; Zeng, Hui; Ye, Hanhui; Zhang, Fujie

    2018-07-17

    During March and April 2016, 11 yellow fever cases were identified in China. We report epidemic and viral information for 10 of these patients, 6 of whom had been vaccinated before travel. Phylogenetic analyses suggest these viruses nested within the diversity of strains endemic to Angola, where an outbreak began in 2015.

  13. Yellow fever virus: genetic and phenotypic diversity and implications for detection, prevention and therapy.

    PubMed

    Beasley, David W C; McAuley, Alexander J; Bente, Dennis A

    2015-03-01

    Yellow fever virus (YFV) is the prototypical hemorrhagic fever virus, yet our understanding of its phenotypic diversity and any molecular basis for observed differences in disease severity and epidemiology is lacking, when compared to other arthropod-borne and haemorrhagic fever viruses. This is, in part, due to the availability of safe and effective vaccines resulting in basic YFV research taking a back seat to those viruses for which no effective vaccine occurs. However, regular outbreaks occur in endemic areas, and the spread of the virus to new, previously unaffected, areas is possible. Analysis of isolates from endemic areas reveals a strong geographic association for major genotypes, and recent epidemics have demonstrated the emergence of novel sequence variants. This review aims to outline the current understanding of YFV genetic and phenotypic diversity and its sources, as well as the available animal models for characterizing these differences in vivo. The consequences of genetic diversity for detection and diagnosis of yellow fever and development of new vaccines and therapeutics are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. International travel between global urban centres vulnerable to yellow fever transmission

    PubMed Central

    Brent, Shannon E; Watts, Alexander; Cetron, Martin; German, Matthew; Kraemer, Moritz UG; Bogoch, Isaac I; Brady, Oliver J; Hay, Simon I; Creatore, Maria I

    2018-01-01

    Abstract Objective To examine the potential for international travel to spread yellow fever virus to cities around the world. Methods We obtained data on the international flight itineraries of travellers who departed yellow fever-endemic areas of the world in 2016 for cities either where yellow fever was endemic or which were suitable for viral transmission. Using a global ecological model of dengue virus transmission, we predicted the suitability of cities in non-endemic areas for yellow fever transmission. We obtained information on national entry requirements for yellow fever vaccination at travellers’ destination cities. Findings In 2016, 45.2 million international air travellers departed from yellow fever-endemic areas of the world. Of 11.7 million travellers with destinations in 472 cities where yellow fever was not endemic but which were suitable for virus transmission, 7.7 million (65.7%) were not required to provide proof of vaccination upon arrival. Brazil, China, India, Mexico, Peru and the United States of America had the highest volumes of travellers arriving from yellow fever-endemic areas and the largest populations living in cities suitable for yellow fever transmission. Conclusion Each year millions of travellers depart from yellow fever-endemic areas of the world for cities in non-endemic areas that appear suitable for viral transmission without having to provide proof of vaccination. Rapid global changes in human mobility and urbanization make it vital for countries to re-examine their vaccination policies and practices to prevent urban yellow fever epidemics. PMID:29875519

  15. Identification of Dengue and Chikungunya Cases Among Suspected Cases of Yellow Fever in the Democratic Republic of the Congo.

    PubMed

    Makiala-Mandanda, Sheila; Ahuka-Mundeke, Steve; Abbate, Jessica L; Pukuta-Simbu, Elisabeth; Nsio-Mbeta, Justus; Berthet, Nicolas; Leroy, Eric Maurice; Becquart, Pierre; Muyembe-Tamfum, Jean-Jacques

    2018-05-16

    For more than 95% of acute febrile jaundice cases identified through surveillance for yellow fever, a reemerging arthropod-borne viral disease, no etiological exploration is ever done. The aim of this study was to test for other arthropod-borne viruses that can induce the same symptoms in patients enrolled in the yellow fever surveillance in the Democratic Republic of the Congo (DRC). Of 652 patients included in the surveillance of yellow fever in DRC from January 2003 to January 2012, 453 patients that tested negative for yellow fever virus (YFV) immunoglobulin M (IgM) antibodies were selected for the study. Real-time polymerase chain reaction was performed for the detection of dengue, West Nile, Chikungunya, O'nyong-nyong, Rift Valley fever, Zika, and YFV. The average age of patients was 22.1 years. We reported 16 cases (3.5%; confidence interval [CI]: 0.8-5.2) of dengue (serotypes 1 and 2) and 2 cases (0.4%; CI: 0.0-1.0) of Chikungunya. Three patients were co-infected with the two serotypes of dengue virus. Three cases of dengue were found in early July 2010 from the city of Titule (Oriental province) during a laboratory-confirmed outbreak of yellow fever, suggesting simultaneous circulation of dengue and yellow fever viruses. This study showed that dengue and Chikungunya viruses are potential causes of acute febrile jaundice in the DRC and highlights the need to consider dengue and Chikungunya diagnosis in the integrated disease surveillance and response program in the DRC. A prospective study is necessary to establish the epidemiology of these diseases.

  16. Dengue-yellow fever sera cross-reactivity; challenges for diagnosis.

    PubMed

    Houghton-Triviño, Natalia; Montaña, Diana; Castellanos, Jaime

    2008-01-01

    The Flavivirus genera share epitopes inducing cross-reactive antibodies leading to great difficulty in differentially diagnosing flaviviral infections. This work was aimed at evaluating the complexity of dengue and yellow fever serological differential diagnosis. Dengue antibody capture ELISA and a yellow fever neutralisation test were carried out on 13 serum samples obtained from yellow fever patients, 20 acute serum samples from dengue patients and 19 voluntary serum samples pre- and post-vaccination with YF vaccine. Dengue ELISA revealed IgM reactivity in 46,2 % of yellow fever patients and 42 % of vaccinees. Sixteen out of 20 dengue patients (80 %) had high YF virus neutralisation titres. Such very high cross-reactivity data challenged differential laboratory diagnosis of dengue and yellow fever in areas where both flaviviruses co-circulate. New laboratory strategies are thus needed for improving the tests and providing a specific laboratory diagnosis. Cross-reactivity between Flaviviruses represents a great difficulty for epidemiological surveillance and preventing dengue, both of which demand urgent attention.

  17. 42 CFR 71.3 - Designation of yellow fever vaccination centers; Validation stamps.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... safe, potent, and pure yellow fever vaccine. Medical facilities of Federal agencies are authorized to obtain yellow fever vaccine without being designated as a yellow fever vaccination center by the Director..., storage, and administration of yellow fever vaccine. If a designated center fails to comply with such...

  18. THE SUSCEPTIBILITY OF MARMOSETS TO YELLOW FEVER VIRUS

    PubMed Central

    Davis, Nelson C.

    1930-01-01

    1. It has been possible to introduce yellow fever virus into the small Brazilian monkeys, Callithrix albicollis and Leontocebus ursulus, by the bites of infected mosquitoes and to carry the virus through a series of four passages in each species and back to rhesus monkeys by the bites of Stegomyia mosquitoes fed on the last marmoset of each series. 2. Five specimens of L. ursulus were used. Four developed fever, and all died during the experiments. At least two showed liver necroses comparable to those found in human beings and rhesus monkeys that died of yellow fever. 3. Twenty specimens of C. albicollis were used. Very few showed a temperature reaction following the introduction of virus. Of those that died, none had lesions typical of yellow fever as seen in certain other species of monkeys and in humans. 4. The convalescent serum from each of five C. albicollis protected a rhesus monkey against yellow fever virus, but the serum from a normal marmoset of the same species was found to be non-protective. PMID:19869773

  19. Present status of yellow fever: memorandum from a PAHO meeting.

    PubMed

    1986-01-01

    An international seminar on the treatment and laboratory diagnosis of yellow fever, sponsored by the Pan American Health Organization (PAHO) and held in 1984, differed from previous meetings on yellow fever because of its emphasis on the care and management of patients and because the participants included specialists from several branches of medicine, such as hepatology, haematology, cardiology, infectious diseases, pathology and nephrology. The meeting reviewed the current status of yellow fever and problems associated with case-finding and notification; features of yellow fever in individual countries of Latin America; health services and facilities for medical care as they relate to diagnosis and management of cases; prevention strategies for and current status of immunization programmes; clinical and pathological aspects of yellow fever in humans; pathogenesis and pathophysiology of yellow fever in experimental animal models; clinical and specific laboratory diagnosis; treatment of the disease and of complications in the functioning of individual organ systems; prognosis and prognostic indicators; and directions for future clinical and experimental research on pathophysiology and treatment.

  20. Serologic assessment of yellow fever immunity in the rural population of a yellow fever-endemic area in Central Brazil.

    PubMed

    Machado, Vanessa Wolff; Vasconcelos, Pedro Fernando da Costa; Silva, Eliana Vieira Pinto; Santos, João Barberino

    2013-01-01

    The yellow fever epidemic that occurred in 1972/73 in Central Brazil surprised the majority of the population unprotected. A clinical-epidemiological survey conducted at that time in the rural area of 19 municipalities found that the highest (13.8%) number of disease cases were present in the municipality of Luziânia, State of Goiás. Thirty-eight years later, a new seroepidemiological survey was conducted with the aim of assessing the degree of immune protection of the rural population of Luziânia, following the continuous attempts of public health services to obtain vaccination coverage in the region. A total of 383 volunteers, aged between 5 and 89 years and with predominant rural labor activities (75.5%), were interviewed. The presence of antibodies against the yellow fever was also investigated in these individuals, by using plaque reduction neutralization test, and correlated to information regarding residency, occupation, epidemiological data and immunity against the yellow fever virus. We found a high (97.6%) frequency of protective titers (>1:10) of neutralizing antibodies against the yellow fever virus; the frequency of titers of 1:640 or higher was 23.2%, indicating wide immune protection against the disease in the study population. The presence of protective immunity was correlated to increasing age. This study reinforces the importance of surveys to address the immune state of a population at risk for yellow fever infection and to the surveillance of actions to control the disease in endemic areas.

  1. STUDIES ON SOUTH AMERICAN YELLOW FEVER

    PubMed Central

    Davis, Nelson C.; Shannon, Raymond C.

    1929-01-01

    Yellow fever virus from M. rhesus has been inoculated into a South American monkey (Cebus macrocephalus) by blood injection and by bites of infected mosquitoes. The Cebus does not develop the clinical or pathological signs of yellow fever. Nevertheless, the virus persists in the Cebus for a time as shown by the typical symptoms and lesions which develop when the susceptible M. rhesus is inoculated from a Cebus by direct transfer of blood or by mosquito (A. aegypti) transmission. PMID:19869607

  2. [Trends in yellow fever mortality in Colombia, 1998-2009].

    PubMed

    Segura, Ángela María; Cardona, Doris; Garzón, María Osley

    2013-09-01

    Yellow fever is a neglected tropical disease, thus, knowing the trends in mortality from this disease in Colombia is an important source of information for decision making and identifying public health interventions. To analyze trends in yellow fever mortality in Colombia during the 1998-2009 period and the differences in the morbidity and mortality information sources for the country, which affect indicators such as the lethality one. This is a descriptive study of deaths by yellow fever according to the Departamento Administrativo Nacional de Estadística and the incidence of the disease according to the Instituto Nacional de Salud . We used secondary sources of information in the calculation of proportions of socio-demographic characteristics of the deceased and epidemiological measures of lethality, incidence and mortality from yellow fever by department of residence of the deceased. Yellow fever deaths occur primarily in men of working age residing in scattered rural areas, who were members of the regimen vinculado, and who were living in the eastern, southeastern, northern and central zones in the country. We observed inconsistencies in the reports that affect the comparative analysis. The inhabitants of the departments located in national territories and Norte de Santander have an increased risk of illness and death from yellow fever, but this information could be underestimated, according to the source of information used for its calculation.

  3. Is it time for a new yellow fever vaccine?

    PubMed

    Hayes, Edward B

    2010-11-29

    An inexpensive live attenuated vaccine (the 17D vaccine) against yellow fever has been effectively used to prevent yellow fever for more than 70 years. Interest in developing new inactivated vaccines has been spurred by recognition of rare but serious, sometimes fatal adverse events following live virus vaccination. A safer inactivated yellow fever vaccine could be useful for vaccinating people at higher risk of adverse events from the live vaccine, but could also have broader global health utility by lowering the risk-benefit threshold for assuring high levels of yellow fever vaccine coverage. If ongoing trials demonstrate favorable immunogenicity and safety compared to the current vaccine, the practical global health utility of an inactivated vaccine is likely to be determined mostly by cost. Copyright © 2010 Elsevier Ltd. All rights reserved.

  4. THE USE OF MICE IN TESTS OF IMMUNITY AGAINST YELLOW FEVER

    PubMed Central

    Sawyer, W. A.; Lloyd, Wray

    1931-01-01

    1. A method of testing sera for protective power against yellow fever is described and designated as the intraperitoneal protection test in mice. 2. The test consists essentially of the inoculation of mice intra-peritoneally with yellow fever virus, fixed for mice, together with the serum to be tested, and the simultaneous injection of starch solution into the brain to localize the virus. If the serum lacks protective power the mice die of yellow fever encephalitis. 3. The test is highly sensitive. Consequently it is useful in epidemiological studies to determine whether individuals have ever had yellow fever and in tests to find whether vaccinated persons or animals have in reality been immunized. 4. When mice were given large intraperitoneal injections of yellow fever virus fixed for mice, the virus could be recovered from the blood for 4 days although encephalitis did not occur. If the brain was mildly injured at the time of the intraperitoneal injection, the symptoms of yellow fever encephalitis appeared 6 days later, but the virus was then absent from the blood. 5. Strains of white mice vary greatly in their susceptibility to yellow fever. PMID:19869938

  5. A Case of Yellow Fever Vaccine–Associated Viscerotropic Disease in Ecuador

    PubMed Central

    Douce, Richard W.; Freire, Diana; Tello, Betzabe; Vásquez, Gavino A.

    2010-01-01

    We report the first case of viscerotropic syndrome in Ecuador. Because of similarities between yellow fever and viscerotropic syndrome, the incidence of this recently described complication of vaccination with the 17D yellow fever vaccine is not known. There is a large population in South America that is considered at risk for possible reemergence of urban yellow fever. Knowledge of potentially fatal complications of yellow fever vaccine should temper decisions to vaccinate populations where the disease is not endemic. PMID:20348528

  6. Modelling the large-scale yellow fever outbreak in Luanda, Angola, and the impact of vaccination.

    PubMed

    Zhao, Shi; Stone, Lewi; Gao, Daozhou; He, Daihai

    2018-01-01

    Yellow fever (YF), transmitted via bites of infected mosquitoes, is a life-threatening viral disease endemic to tropical and subtropical regions of Africa and South America. YF has largely been controlled by widespread national vaccination campaigns. Nevertheless, between December 2015 and August 2016, YF resurged in Angola, quickly spread and became the largest YF outbreak for the last 30 years. Recently, YF resurged again in Brazil (December 2016). Thus, there is an urgent need to gain better understanding of the transmission pattern of YF. The present study provides a refined mathematical model, combined with modern likelihood-based statistical inference techniques, to assess and reconstruct important epidemiological processes underlying Angola's YF outbreak. This includes the outbreak's attack rate, the reproduction number ([Formula: see text]), the role of the mosquito vector, the influence of climatic factors, and the unusual but noticeable appearance of two-waves in the YF outbreak. The model explores actual and hypothetical vaccination strategies, and the impacts of possible human reactive behaviors (e.g., response to media precautions). While there were 73 deaths reported over the study period, the model indicates that the vaccination campaign saved 5.1-fold more people from death and saved from illness 5.6-fold of the observed 941 cases. Delaying the availability of the vaccines further would have greatly worsened the epidemic in terms of increased cases and deaths. The analysis estimated a mean [Formula: see text] and an attack rate of 0.09-0.15% (proportion of population infected) over the whole period from December 2015 to August 2016. Our estimated lower and upper bounds of [Formula: see text] are in line with previous studies. Unusually, [Formula: see text] oscillated in a manner that was "delayed" with the reported deaths. High recent number of deaths were associated (followed) with periods of relatively low disease transmission and low [Formula

  7. Travelers' Health: Yellow Fever

    MedlinePlus

    ... and local rate of virus transmission at the time of travel. Although reported cases of human disease are the ... be receiving yellow fever vaccine for the first time. If travel is unavoidable, the decision to vaccinate travelers aged ≥ ...

  8. Transmission of yellow fever vaccine virus through breast-feeding - Brazil, 2009.

    PubMed

    2010-02-12

    In April, 2009, the state health department of Rio Grande do Sul, Brazil, was notified by the Cachoeira do Sul municipal health department of a case of meningoencephalitis requiring hospitalization in an infant whose mother recently had received yellow fever vaccine during a postpartum visit. The Field Epidemiology Training Program of the Secretariat of Surveillance in Health of the Brazilian Ministry of Health assisted state and municipal health departments with an investigation. This report summarizes the results of that investigation, which determined that the infant acquired yellow fever vaccine virus through breast-feeding. The mother reported 2 days of headache, malaise, and low fever occurring 5 days after receipt of yellow fever vaccine. The infant, who was exclusively breast-fed, was hospitalized at age 23 days with seizures requiring continuous infusion of intravenous anticonvulsants. The infant received antimicrobial and antiviral treatment for meningoencephalitis. The presence of 17DD yellow fever virus was detected by reverse transcription--polymerase chain reaction (RT-PCR) in the infant's cerebrospinal fluid (CSF); yellow fever--specific immunoglobulin M (IgM) antibodies also were present in serum and CSF. The infant recovered completely, was discharged after 24 days of hospitalization, and has had normal neurodevelopment and growth through age 6 months. The findings in this report provide documentation that yellow fever vaccine virus can be transmitted via breast-feeding. Administration of yellow fever vaccine to breast-feeding women should be avoided except in situations where exposure to yellow fever viruses cannot be avoided or postponed.

  9. What a rheumatologist needs to know about yellow fever vaccine.

    PubMed

    Oliveira, Ana Cristina Vanderley; Mota, Licia Maria Henrique da; Santos-Neto, Leopoldo Luiz Dos; Tauil, Pedro Luiz

    2013-04-01

    Patients with rheumatic diseases are more susceptible to infection, due to the underlying disease itself or to its treatment. The rheumatologist should prevent infections in those patients, vaccination being one preventive measure to be adopted. Yellow fever is one of such infectious diseases that can be avoided.The yellow fever vaccine is safe and effective for the general population, but, being an attenuated live virus vaccine, it should be avoided whenever possible in rheumatic patients on immunosuppressive drugs. Considering that yellow fever is endemic in a large area of Brazil, and that vaccination against that disease is indicated for those living in such area or travelling there, rheumatologists need to know that disease, as well as the indications for the yellow fever vaccine and contraindications to it. Our paper was aimed at highlighting the major aspects rheumatologists need to know about the yellow fever vaccine to decide about its indication or contraindication in specific situations. 2013 Elsevier Editora Ltda. All rights reserved.

  10. Serious adverse events associated with yellow fever vaccine.

    PubMed

    de Menezes Martins, Reinaldo; Fernandes Leal, Maria da Luz; Homma, Akira

    2015-01-01

    Yellow fever vaccine was considered one of the safest vaccines, but in recent years it was found that it could rarely cause invasive and disseminated disease in some otherwise healthy individuals, with high lethality. After extensive studies, although some risk factors have been identified, the real cause of causes of this serious adverse event are largely unknown, but findings point to individual host factors. Meningoencephalitis, once considered to happen only in children less than 6 months of age, has also been identified in older children and adults, but with good prognosis. Efforts are being made to develop a safer yellow fever vaccine, and an inactivated vaccine or a vaccine prepared with the vaccine virus envelope produced in plants are being tested. Even with serious and rare adverse events, yellow fever vaccine is the best way to avoid yellow fever, a disease of high lethality and should be used routinely in endemic areas, and on people from non-endemic areas that could be exposed, according to a careful risk-benefit analysis.

  11. Severe post-vaccination reaction to 17D yellow fever vaccine in Nigeria.

    PubMed

    Oyelami, S A; Olaleye, O D; Oyejide, C O; Omilabu, S A; Fatunla, B A

    1994-01-01

    An unusual outbreak of post-vaccination reactions to 17D yellow fever vaccine occurred at Shaki, Nigeria, in May 1987. Twenty-five of the affected people were treated at the Baptist Hospital Shaki. The patients presented with rapidly progressing swelling of the left arm with associated fever and other constitutional symptoms few hours after inoculation with the vaccine. Some of the patients developed gangrene of the affected limb, five of them went into coma and died. Poor hygiene and improper handling of vaccine as well as contamination of vaccine from the source are possible causes. A review of vaccine delivery strategies especially at local community levels; sound training, supervision of vaccinators and health education are strongly recommended to prevent reoccurrence of similar reactions.

  12. Traveling Abroad: Latest Yellow Fever Vaccine Update | Poster

    Cancer.gov

    Earlier this month, the U.S. Centers for Disease Control and Prevention (CDC) released its list of clinics that are administering the yellow fever vaccine Stamaril, which has been made available to address the total depletion of the United States’ primary yellow fever vaccine, YF-VAX. These clinics will provide the vaccine to individuals preparing for international travel,

  13. Yellow Fever in an Unvaccinated Traveler to Peru.

    PubMed

    Winnicka, Lydia; Abdullah, Amirahwaty; Yang, Tsujung; Norville, Kim; Irizarry-Acosta, Melina

    2017-01-01

    We present a case of an unvaccinated traveler who traveled from New York to Peru and contracted yellow fever. He likely acquired the infection while visiting the Amazon River, with a point of exit of Lima, Peru. Our case illustrates the dramatic course that yellow fever may take, as well as the importance of pretravel vaccination.

  14. Current Assessment of Yellow Fever and Yellow Fever Vaccine.

    PubMed

    Lefeuvre, Anabelle; Marianneau, Philippe; Deubel, Vincent

    2004-04-01

    Yellow fever (YF) is a mosquito-borne viral illness that causes hemorrhagic fever in tropical Africa and South America. Although a very safe and efficient vaccine (17D) is available, it is underused. An estimated 200,000 people are still infected annually, and YF remains a major public health concern. This article reviews the recent data on YF epidemiology, virology, and immunity, and analyzes the rare postvaccination adverse effects that have been recently reported. YF vaccine should be included in the expanded program of immunization for children and sustained for people living in or traveling to endemic areas. A surveillance of vaccinated people also should be reinforced. New research programs should be developed to identify molecular markers of YF virus tropism and attenuation, and to understand mechanisms of host responses to virus infection.

  15. Unexpected Rift Valley Fever Outbreak, Northern Mauritania

    PubMed Central

    El Mamy, Ahmed B. Ould; Baba, Mohamed Ould; Barry, Yahya; Isselmou, Katia; Dia, Mamadou L.; Hampate, Ba; Diallo, Mamadou Y.; El Kory, Mohamed Ould Brahim; Diop, Mariam; Lo, Modou Moustapha; Thiongane, Yaya; Bengoumi, Mohammed; Puech, Lilian; Plee, Ludovic; Claes, Filip; Doumbia, Baba

    2011-01-01

    During September–October 2010, an unprecedented outbreak of Rift Valley fever was reported in the northern Sahelian region of Mauritania after exceptionally heavy rainfall. Camels probably played a central role in the local amplification of the virus. We describe the main clinical signs (hemorrhagic fever, icterus, and nervous symptoms) observed during the outbreak. PMID:22000364

  16. The yellow Fever epidemic in Western mali, september-november 1987: why did epidemiological surveillance fail?

    PubMed

    Kurz, X

    1990-03-01

    Recent yellow fever epidemics in West Africa have underlined the discrepancy between the official number of cases and deaths and those estimated by a retrospective epidemiological investigation. During the yellow fever epidemic that broke out in western Mali in September 1987, a total of 305 cases and 145 deaths were officially notified, but estimates revealed true figures abut five times higher. This paper attempts to discuss the factors that hindered early case detection and more complete reporting. They were, first, the insufficient training on the clinical diagnosis, the blood sampling method for laboratory confirmation, and the curative treatment of patients (resulting in low utilization of services); second, the lack of an action plan to prepare in advance a quick response to the epidemic, affecting reporting procedures at the peripheral level and active case-finding during the outbreak; and third, the lack of laboratory facilities for a quick confirmation of the disease. The difficulties experienced during the yellow fever epidemic in Mali demonstrated the importance of a preparedness strategy for epidemic control, based on an integrated approach of epidemiological surveillance within basic health service activities. The need for regional collaboration and for institutionalized funds in the donor community that could be mobilized for epidemic preparedness activities is also emphasized.

  17. Yellow fever, Asia and the East African slave trade.

    PubMed

    Cathey, John T; Marr, John S

    2014-05-01

    Yellow fever is endemic in parts of sub-Saharan Africa and South America, yet its principal vectors--species of mosquito of the genus Aedes--are found throughout tropical and subtropical latitudes. Phylogenetic analyses indicate that yellow fever originated in Africa and that its spread to the New World coincided with the slave trade, but why yellow fever has never appeared in Asia remains a mystery. None of several previously proposed explanations for its absence there is considered satisfactory. We contrast the trans-Atlantic slave trade, and trade across the Sahara and to the Arabian Peninsula and Mesopotamia, with that to Far East and Southeast Asian ports before abolition of the African slave trade, and before the scientific community understood the transmission vector of yellow fever and the viral life cycle, and the need for shipboard mosquito control. We propose that these differences in slave trading had a primary role in the avoidance of yellow fever transmission into Asia in the centuries before the 20(th) century. The relatively small volume of the Black African slave trade between Africa and East and Southeast Asia has heretofore been largely ignored. Although focal epidemics may have occurred, the volume was insufficient to reach the threshold for endemicity.

  18. Traveling Abroad: Latest Yellow Fever Vaccine Update | Poster

    Cancer.gov

    Earlier this month, the U.S. Centers for Disease Control and Prevention (CDC) released its list of clinics that are administering the yellow fever vaccine Stamaril, which has been made available to address the total depletion of the United States’ primary yellow fever vaccine, YF-VAX. These clinics will provide the vaccine to individuals preparing for international travel, including NCI at Frederick staff and scientists.

  19. Modelling the large-scale yellow fever outbreak in Luanda, Angola, and the impact of vaccination

    PubMed Central

    Zhao, Shi; Stone, Lewi; Gao, Daozhou

    2018-01-01

    Background Yellow fever (YF), transmitted via bites of infected mosquitoes, is a life-threatening viral disease endemic to tropical and subtropical regions of Africa and South America. YF has largely been controlled by widespread national vaccination campaigns. Nevertheless, between December 2015 and August 2016, YF resurged in Angola, quickly spread and became the largest YF outbreak for the last 30 years. Recently, YF resurged again in Brazil (December 2016). Thus, there is an urgent need to gain better understanding of the transmission pattern of YF. Model The present study provides a refined mathematical model, combined with modern likelihood-based statistical inference techniques, to assess and reconstruct important epidemiological processes underlying Angola’s YF outbreak. This includes the outbreak’s attack rate, the reproduction number (R0), the role of the mosquito vector, the influence of climatic factors, and the unusual but noticeable appearance of two-waves in the YF outbreak. The model explores actual and hypothetical vaccination strategies, and the impacts of possible human reactive behaviors (e.g., response to media precautions). Findings While there were 73 deaths reported over the study period, the model indicates that the vaccination campaign saved 5.1-fold more people from death and saved from illness 5.6-fold of the observed 941 cases. Delaying the availability of the vaccines further would have greatly worsened the epidemic in terms of increased cases and deaths. The analysis estimated a mean R0≈2.6-3.4 and an attack rate of 0.09-0.15% (proportion of population infected) over the whole period from December 2015 to August 2016. Our estimated lower and upper bounds of R0 are in line with previous studies. Unusually, R0 oscillated in a manner that was “delayed” with the reported deaths. High recent number of deaths were associated (followed) with periods of relatively low disease transmission and low R0, and vice-versa. The time

  20. A real-time reverse transcription loop-mediated isothermal amplification assay for the rapid detection of yellow fever virus.

    PubMed

    Kwallah, Allan ole; Inoue, Shingo; Muigai, Anne W T; Kubo, Toru; Sang, Rosemary; Morita, Kouichi; Mwau, Matilu

    2013-10-01

    Yellow fever, a mosquito-borne disease, is an important viral hemorrhagic fever in Africa and South America where it is endemic. Detection of yellow fever virus (YFV) in Africa remains a challenge due to a lack of highly specific tests. The aim of this study was to develop and optimize a rapid detection reverse transcription loop-mediated isothermal amplification (RT-LAMP) for YFV. The RT-LAMP was done isothermally at 62 °C using a real-time turbidimeter that allowed detection within 1h. Specificity of the RT-LAMP was determined using RNA from flaviviruses and other related viruses where only YFV RNA was detected: West Nile virus, dengue viruses, Japanese encephalitis virus, Rift Valley fever virus, and chikungunya virus. In addition, equal sensitivity was also observed when the RT-LAMP and the real-time RT-PCR were compared using YFV-spiked human serum samples with a detection limit of 0.29 PFU/ml. Two Kenyan YFV wild strains showed an equal detection limit as the vaccine strain 17D in this study. The RT-LAMP reduced the time of reaction from 3h to 1h and increased sensitivity tenfold compared to RT-PCR. Therefore, this test offers a simple, rapid and reliable diagnostic tool for yellow fever when there are outbreaks of acute hemorrhagic fever in Kenya and other African countries. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Yellow Fever Vaccine Booster Doses: Recommendations of the Advisory Committee on Immunization Practices, 2015.

    PubMed

    Staples, J Erin; Bocchini, Joseph A; Rubin, Lorry; Fischer, Marc

    2015-06-19

    On February 26, 2015, the Advisory Committee on Immunization Practices (ACIP) voted that a single primary dose of yellow fever vaccine provides long-lasting protection and is adequate for most travelers. ACIP also approved recommendations for at-risk laboratory personnel and certain travelers to receive additional doses of yellow fever vaccine (Box). The ACIP Japanese Encephalitis and Yellow Fever Vaccines Workgroup evaluated published and unpublished data on yellow fever vaccine immunogenicity and safety. The evidence for benefits and risks associated with yellow fever vaccine booster doses was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework. This report summarizes the evidence considered by ACIP and provides the updated recommendations for yellow fever vaccine booster doses.

  2. Yellow fever virus vaccine-associated deaths in young women.

    PubMed

    Seligman, Stephen J

    2011-10-01

    Yellow fever vaccine-associated viscerotropic disease is a rare sequela of live-attenuated virus vaccine. Elderly persons and persons who have had thymectomies have increased susceptibility. A review of published and other data suggested a higher than expected number of deaths from yellow fever vaccine-associated viscerotropic disease among women 19-34 years of age without known immunodeficiency.

  3. An epidemic of sylvatic yellow fever in the southeast region of Maranhao State, Brazil, 1993-1994: epidemiologic and entomologic findings.

    PubMed

    Vasconcelos, P F; Rodrigues, S G; Degallier, N; Moraes, M A; da Rosa, J F; da Rosa, E S; Mondet, B; Barros, V L; da Rosa, A P

    1997-08-01

    Yellow fever virus transmission was very active in Maranhao State in Brazil in 1993 and 1994. An investigation was carried out to evaluate the magnitude of the epidemic. In 1993, a total of 932 people was examined for yellow fever from Maranhao: 70 were positive serologically, histopathologically, and/or by virus isolation, and another four cases were diagnosed clinically and epidemiologically. In Mirador (17,565 inhabitants), the incidence was 3.5 per 1,000 people (case fatality rate [number of deaths/number of cases diagnosed] = 16.4%), while in a rural yellow fever risk area (14,659 inhabitants), the incidence was 4.2 and the case-fatality rate was 16.1% (10 of 62). A total of 45.2% (28 of 62) asymptomatic infections were registered. In 1994, 49 serum samples were obtained and 16 cases were confirmed (two by virus isolation, two by seroconversion, and 12 by serology). No fatal cases were reported. In 1993, 936 potential yellow fever vectors were captured in Mirador and a single strain was isolated from a pool of Haemagogus janthinomys (infection rate = 0.16%). In 1994, 16 strains were isolated from 1,318 Hg. janthinomys (infection rate = 1.34%) and one Sabethes chloropterus (infection rate = 1.67%). Our results suggest that this was the most extensive outbreak of yellow fever in the last 20 years in Brazil. It is also clear that the lack of vaccination was the principal reason for the epidemic, which occurred between April and June, during the rainy season, a period in which the mosquito population in the forest increases.

  4. [The "plague" of Barcelona. Yellow fever epidemic of 1821].

    PubMed

    Chastel, C

    1999-12-01

    The outbreak of yellow fever that struck Barcelona in 1821 followed a typical pattern for the times: a brick from Cuba introduced the disease in the port docks; the epidemic first reached the poor suburbs, and finally the center of the city. It was assumed that at least 20,000 inhabitants died from the scourge, that is a sixth of the total population of the city estimated 120,000. French authorities promptly took emergency measures at land and maritime borders by locking French ports to Catalan vessels and defining a quarantine line along the Pyrenean border controlled by an army 15,000 strong. French medical team including six physicians and two nuns was sent to Barcelona to provide assistance. Long after the epidemic had receded, the Pyrenean quarantine line was maintained by the French authorities for a hidden political purpose: Paris wished to contain Spanish Liberalism, a "revolutionary pest". French troops engaged in the so-called quarantine line were used in 1823 for invading the Spanish kingdom, while French physicians returning to Paris were celebrated as heroes and benefactors of the mankind although they had not provided any serious contribution to the therapeutics or the epidemiology of yellow fever. They were glorified in publications of the time without reserve. This unexpected manifestation of nationalism was welcomed and encouraged by the government of Louis XVIII who felt himself threatened by the liberal opposition.

  5. Animal models of yellow fever and their application in clinical research.

    PubMed

    Julander, Justin G

    2016-06-01

    Yellow fever virus (YFV) is an arbovirus that causes significant human morbidity and mortality. This virus has been studied intensively over the past century, although there are still no treatment options for those who become infected. Periodic and unpredictable yellow fever (YF) outbreaks in Africa and South America continue to occur and underscore the ongoing need to further understand this viral disease and to develop additional countermeasures to prevent or treat cases of illness. The use of animal models of YF is critical to accomplishing this goal. There are several animal models of YF that replicate various aspects of clinical disease and have provided insight into pathogenic mechanisms of the virus. These typically include mice, hamsters and non-human primates (NHP). The utilities and shortcomings of the available animal models of YF are discussed. Information on recent discoveries that have been made in the field of YFV research is also included as well as important future directions in further ameliorating the morbidity and mortality that occur as a result of YFV infection. It is anticipated that these model systems will help facilitate further improvements in the understanding of this virus and in furthering countermeasures to prevent or treat infections. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Persistence of yellow fever vaccine-induced antibodies after solid organ transplantation.

    PubMed

    Wyplosz, B; Burdet, C; François, H; Durrbach, A; Duclos-Vallée, J C; Mamzer-Bruneel, M-F; Poujol, P; Launay, O; Samuel, D; Vittecoq, D; Consigny, P H

    2013-09-01

    Immunization using live attenuated vaccines represents a contra-indication after solid organ transplantation (SOT): consequently, transplant candidates planning to travel in countries where yellow fever is endemic should be vaccinated prior to transplantation. The persistence of yellow fever vaccine-induced antibodies after transplantation has not been studied yet. We measured yellow-fever neutralizing antibodies in 53 SOT recipients vaccinated prior to transplantation (including 29 kidney recipients and 18 liver recipients). All but one (98%) had protective titers of antibodies after a median duration of 3 years (min.: 0.8, max.: 21) after transplantation. The median antibody level was 40 U/L (interquartile range: 40-80). For the 46 patients with a known or estimated date of vaccination, yellow-fever antibodies were still detectable after a median time of 13 years (range: 2-32 years) post-immunization. Our data suggest there is long-term persistence of antibodies to yellow fever in SOT recipients who have been vaccinated prior to transplantation. © Copyright 2013 The American Society of Transplantation and the American Society of Transplant Surgeons.

  7. [Control discourses and power relations of yellow fever: Philadelphia in 1793].

    PubMed

    Kim, Seohyung

    2014-12-01

    1793 Yellow fever in Philadelphia was the most severe epidemics in the late 18th century in the United States. More than 10% of the population in the city died and many people fled to other cities. The cause of yellow fever in the United States had close relationship with slaves and sugar in Philadelphia. Sugarcane plantation had needed many labors to produce sugar and lots of Africans had to move to America as slaves. In this process, Aëdes aegypti, the vector of yellow fever had migrated to America and the circumstances of ships or cities provided appropriate conditions for its breeding. In this period, the cause of yellow fever could not be established exactly, so suggestions of doctors became entangled in political and intellectual discourses in American society. There was a critical conflict between Jeffersonian Republicanism and Federalism about the origin and treatment of yellow fever. Benjamin Rush, a Jeffersonian Republican, suggested urban sanitation reform and bloodletting. He believed the infectious disease happened because of unsanitary city condition, so he thought the United States could be a healthy nation by improvement of the public health and sanitation. He would like to cope with national crisis and develop American society on the basis of republicanism. While Rush suggested the improvement of public health and sanitation, the city government of Philadelphia suggested isolation of yellow fever patients and quarantine. City government isolated the patients from healthy people and it reconstructed space of hospital. Also, it built orphanages to take care of children who lost their parents during the epidemic and implemented power to control people put in the state of exception. Of course, city government tried to protect the city and nation by quarantine of every ship to Philadelphia. Control policies of yellow fever in 1793 showed different conflicts and interactions. Through the yellow fever, Jeffersonian Republicanism and Federalism had

  8. Isolation and characterization of a Brazilian strain of yellow fever virus from an epizootic outbreak in 2009.

    PubMed

    Jorge, Taissa Ricciardi; Mosimann, Ana Luiza Pamplona; Noronha, Lucia de; Maron, Angela; Duarte Dos Santos, Claudia Nunes

    2017-02-01

    During a series of epizootics caused by Yellow fever virus in Brazil between 2007 and 2009, a monkey was found dead (May 2009) in a sylvatic area in the State of Paraná. Brain samples from this animal were used for immunohistochemical analysis and isolation of a wild-type strain of YFV. This viral strain was characterized, and sequence analyzes demonstrated that it is closely related with YFV strains of the recently identified subclade 1E of the South American genotype I. Further characterization included indirect-immunofluorescence of different infected cell lines and analysis of the kinetics of virus replication and infectivity inhibition by type I IFN. The generated data contributes to the knowledge of YFV evolution and phylogeny. Additionally, the reagents generated and characterized during this study, such as a panel of monoclonal antibodies, are useful tools for further studies on YFV. Lastly, this case stresses the importance of yellow fever surveillance through sentinel monkeys. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. A Novel Benzodiazepine Compound Inhibits Yellow Fever Virus Infection by Specifically Targeting NS4B Protein.

    PubMed

    Guo, Fang; Wu, Shuo; Julander, Justin; Ma, Julia; Zhang, Xuexiang; Kulp, John; Cuconati, Andrea; Block, Timothy M; Du, Yanming; Guo, Ju-Tao; Chang, Jinhong

    2016-09-21

    Although a highly effective vaccine is available, the number of yellow fever cases has increased over the past two decades, which highlights the pressing need for antiviral therapeutics. In a high throughput screening campaign, we identified an acetic acid benzodiazepine (BDAA) compound, which potently inhibits yellow fever virus (YFV). Interestingly, while treatment of YFV infected cultures with 2 μM of BDAA reduced the virion production by greater than 2 logs, the compound is not active against 21 other viruses from 14 different viral families. Selection and genetic analysis of drug resistant viruses revealed that substitution of proline at amino acid 219 (P219) of the nonstructural protein 4B (NS4B) with serine, threonine or alanine confers YFV resistance to BDAA without apparent loss of replication fitness in cultured mammalian cells. However, substitution of P219 with glycine confers BDAA resistance with significant loss of replication ability. Bioinformatics analysis predicts that the P219 localizes at the endoplasmic reticulum lumen side of the fifth putative trans-membrane domain of NS4B and the mutation may render the viral protein incapable of interacting with BDAA. Our studies thus revealed important role and structural basis for NS4B protein in supporting YFV replication. Moreover, in YFV-infected hamsters, oral administration of BDAA protected 90% of the animals from death, significantly reduced viral load by greater than 2 logs and attenuated viral infection-induced liver injury and body weight loss. The encouraging preclinical results thus warrant further development of BDAA or its derivatives as antiviral agents to treat yellow fever. Yellow fever is an acute viral hemorrhagic disease which threatens approximately one billion people living in tropical areas of Africa and Latin America. Although a highly effective yellow fever vaccine has been available for more than seven decades, the low vaccination rate fails to prevent outbreaks in at

  10. A Novel Benzodiazepine Compound Inhibits Yellow Fever Virus Infection by Specifically Targeting NS4B Protein

    PubMed Central

    Guo, Fang; Wu, Shuo; Julander, Justin; Ma, Julia; Zhang, Xuexiang; Kulp, John; Cuconati, Andrea; Block, Timothy M.; Du, Yanming; Guo, Ju-Tao

    2016-01-01

    rate fails to prevent outbreaks in at-risk regions. It has been estimated that up to 1.7 million YFV infections occur in Africa each year, resulting in 29,000 to 60,000 deaths. Thus far, there is no specific antiviral treatment for yellow fever. To cope with this medical challenge, we identified a benzodiazepine compound that selectively inhibits YFV by targeting the viral NS4B protein. To our knowledge, this is the first report demonstrating in vivo safety and antiviral efficacy of a YFV NS4B inhibitor in an animal model. We have thus reached a critical milestone toward the development of specific antiviral therapeutics for clinical management of yellow fever. PMID:27654301

  11. Yellow fever vaccine-associated neurological disease, a suspicious case.

    PubMed

    Beirão, Pedro; Pereira, Patrícia; Nunes, Andreia; Antunes, Pedro

    2017-03-02

    A 70-year-old man with known cardiovascular risk factors, presented with acute onset expression aphasia, agraphia, dyscalculia, right-left disorientation and finger agnosia, without fever or meningeal signs. Stroke was thought to be the cause, but cerebrovascular disease investigation was negative. Interviewing the family revealed he had undergone yellow fever vaccination 18 days before. Lumbar puncture revealed mild protein elevation. Cultural examinations, Coxiella burnetti, and neurotropic virus serologies were negative. Regarding the yellow fever virus, IgG was identified in serum and cerebrospinal fluid (CSF), with negative IgM and virus PCR in CSF. EEG showed an encephalopathic pattern. The patient improved gradually and a week after discharge was his usual self. Only criteria for suspect neurotropic disease were met, but it's possible the time spent between symptom onset and lumbar puncture prevented a definite diagnosis of yellow fever vaccine-associated neurological disease. This gap would have been smaller if the vaccination history had been collected earlier. 2017 BMJ Publishing Group Ltd.

  12. Estimating the number of unvaccinated Chinese workers against yellow fever in Angola.

    PubMed

    Wilder-Smith, A; Massad, E

    2018-04-17

    A yellow fever epidemic occurred in Angola in 2016 with 884 laboratory confirmed cases and 373 deaths. Eleven unvaccinated Chinese nationals working in Angola were also infected and imported the disease to China, thereby presenting the first importation of yellow fever into Asia. In Angola, there are about 259,000 Chinese foreign workers. The fact that 11 unvaccinated Chinese workers acquired yellow fever suggests that many more Chinese workers in Angola were not vaccinated. We applied a previously developed model to back-calculate the number of unvaccinated Chinese workers in Angola in order to determine the extent of lack of vaccine coverage. Our models suggest that none of the 259,000 Chinese had been vaccinated, although yellow fever vaccination is mandated by the International Health Regulations. Governments around the world including China need to ensure that their citizens obtain YF vaccination when traveling to countries where such vaccines are required in order to prevent the international spread of yellow fever.

  13. Genomic and Phylogenetic Characterization of Brazilian Yellow Fever Virus Strains

    PubMed Central

    Palacios, Gustavo; Cardoso, Jedson F.; Martins, Livia C.; Sousa, Edivaldo C.; de Lima, Clayton P. S.; Medeiros, Daniele B. A.; Savji, Nazir; Desai, Aaloki; Rodrigues, Sueli G.; Carvalho, Valeria L.; Lipkin, W. Ian

    2012-01-01

    Globally, yellow fever virus infects nearly 200,000 people, leading to 30,000 deaths annually. Although the virus is endemic to Latin America, only a single genome from this region has been sequenced. Here, we report 12 Brazilian yellow fever virus complete genomes, their genetic traits, phylogenetic characterization, and phylogeographic dynamics. Variable 3′ noncoding region (3′NCR) patterns and specific mutations throughout the open reading frame altered predicted secondary structures. Our findings suggest that whereas the introduction of yellow fever virus in Brazil led to genotype I-predominant dispersal throughout South and Central Americas, genotype II remained confined to Bolivia, Peru, and the western Brazilian Amazon. PMID:23015713

  14. Arthropod-borne viral infections associated with a fever outbreak in the northern province of Sudan.

    PubMed

    Watts, D M; el-Tigani, A; Botros, B A; Salib, A W; Olson, J G; McCarthy, M; Ksiazek, T G

    1994-08-01

    An outbreak of acute febrile illness occurred during August and September 1989 in the Northern Province of Sudan coinciding with a high population density of phlebotomine sandflies. An investigation was conducted to determine whether arboviruses were associated with human illness during this outbreak. Sera were obtained from 185 febrile individuals and tested for IgG and IgM antibody to selected arboviruses by enzyme immunoassay (EIA). The prevalence of IgG antibody was 59% for West Nile (WN), 53% for Sandfly Fever Sicilian (SFS), 32% for Sandfly Fever Naples (SFN), 39% for Yellow Fever (YF), 24% for dengue-2 (DEN-2), 23% for Rift Valley Fever (RVF), 12% for Chikungunya (CHIK) and 5% for Crimean-Congo haemorrhagic Fever (CCHF) viruses. Antibody prevalences tended to increase with age for WN and YF viruses. Antibody rates were about the same for males and females for most of the viruses tested. The prevalence of IgM antibody to SFN was 24% and reciprocal IgM titre exceeded 12,800 for some individuals suggesting that this virus was the cause of recent infection. The prevalence of IgM antibody for the other viruses did not exceed 5%. The study indicated that several arboviruses were endemic and some of them may have caused human disease in the Northern Province of Sudan.

  15. An outbreak of scarlet fever in a primary school.

    PubMed

    Lamden, K H

    2011-04-01

    Scarlet fever, due to infection with an erythrogenic toxin-producing Group A streptococcus, is an uncommon and generally mild illness, although serious sequelae do occur. In March 2009, 57 of the 126 (45%) pupils in a primary school in Lancashire, UK developed scarlet fever over a 4-week period. Infection was transmitted via direct contact between pupils, particularly among the youngest pupils. A significant degree of transmission also occurred between siblings. The median number of days absent from school was 3 (range 1-10 days). No children were hospitalised. Control measures, including hygiene advice to the school and exclusion of pupils for 24h while initiating penicillin treatment, were ineffective. The outbreak occurred against a background of an unusually high incidence of invasive Group A streptococcal infection. While there are national guidelines for the control of invasive disease, none exist for the control of scarlet fever outbreaks. This prolonged outbreak of scarlet fever highlights the need for an evidence based approach to outbreak management.

  16. [Detection and management of the yellow fever epidemic in the Ivory Coast, 2001].

    PubMed

    Akoua-Koffi, C; Ekra, K D; Kone, A B; Dagnan, N S; Akran, V; Kouadio, K L; Loukou, Y G; Odehouri, K; Tagliante-Saracino, J; Ehouman, A

    2002-01-01

    From March to December 2001, an outbreak of yellow fever was observed in Cote d'Ivoire. Sentinel surveillance for hemorrhagic fever allowed detection of the first case in the Duekoue health district in the heavily wooded western part of the country. A weekly reporting system was established. For each suspected case recorded and reported to the Epidemiological Surveillance Department at the National Institute of Public Hygiene, a sample was collected and sent for confirmation at the Pasteur Institute of the Cote d'Ivoire. The outbreak progressed from West to East reaching Abidjan, the economic capital of the country located in the southeast. The epidemic emergency plan consisted of setting up a crisis committee to implement epidemiological, entomological and virological surveillance, mass vaccination campaigns in areas around confirmed cases, and vector control. A total of 280 cases were reported including 32 confirmed cases and 6 deaths. Eleven out of 62 districts were affected with most cases occurring in cities with more than 10000 inhabitants. Over 3.7 million persons were vaccinated for an overall coverage of 92.2% in the areas where campaigns were carried out. As a result of this outbreak, surveillance for potentially epidemic diseases has been reinforced and surveillance of viral transmission is now being considered. A vaccination program for adults has also been established.

  17. The Global Distribution of Yellow Fever and Dengue

    PubMed Central

    Rogers, D.J.; Wilson, A.J.; Hay, S.I.; Graham, A.J.

    2011-01-01

    Yellow fever has been subjected to partial control for decades, but there are signs that case numbers are now increasing globally, with the risk of local epidemic outbreaks. Dengue case numbers have also increased dramatically during the past 40 years and different serotypes have invaded new geographical areas. Despite the temporal changes in these closely related diseases, and their enormous public health impact, few attempts have been made to collect a comprehensive dataset of their spatial and temporal distributions. For this review, records of the occurrence of both diseases during the 20th century have been collected together and are used to define their climatic limits using remotely sensed satellite data within a discriminant analytical model framework. The resulting risk maps for these two diseases identify their different environmental requirements, and throw some light on their potential for co-occurrence in Africa and South East Asia. PMID:16647971

  18. Enzootic Transmission of Yellow Fever Virus in Peru

    PubMed Central

    Bryant, Juliet; Wang, Heiman; Cabezas, Cesar; Ramirez, Gladys; Watts, Douglas; Russell, Kevin

    2003-01-01

    The prevailing paradigm of yellow fever virus (YFV) ecology in South America is that of wandering epizootics. The virus is believed to move from place to place in epizootic waves involving monkeys and mosquitoes, rather than persistently circulating within particular locales. After a large outbreak of YFV illness in Peru in 1995, we used phylogenetic analyses of virus isolates to reexamine the hypothesis of virus movement. We sequenced a 670-nucleotide fragment of the prM/E gene region of from 25 Peruvian YFV samples collected from 1977 to 1999, and delineated six clades representing the states (Departments) of Puno, Pasco, Junin, Ayacucho, San Martin/Huanuco, and Cusco. The concurrent appearance of at least four variants during the 1995 epidemic and the genetic stability of separate virus lineages over time, indicate that Peruvian YFV is locally maintained and circulates continuously in discrete foci of enzootic transmission. PMID:12967489

  19. Is the absence or intermittent YF vaccination the major contributor to its persistent outbreaks in eastern Africa?

    PubMed

    Baba, Marycelin Mandu; Ikusemoran, Mayomi

    2017-10-28

    Despite the availability of a safe and efficacious yellow fever vaccine since 1937, yellow fever remains a public health threat as a re-emerging disease in Africa and South America. We reviewed the trend of reported yellow fever outbreaks in eastern African countries, identified the risk epidemiological factors associated with the outbreaks and assessed the current situation of Yellow Fever vaccination in Africa. Surveillance and case finding for yellow fever in Africa are insufficient primarily due to lack of appropriate diagnostic capabilities, poor health infrastructure resulting in under-recognition, underreporting and underestimation of the disease. Despite these challenges, Ethiopia reported 302,614 cases (30,505 deaths) in 1943-2015, Kenya had 207 cases (38 deaths) in 1992-2016, Sudan experienced 31,750 suspected cases (1855 deaths) from 1940 to 2012 and Uganda had 452 cases (65 deaths) in 1941-2016. Major risk factors associated with past yellow fever outbreaks include climate, human practices and virus genetics. Comparisons between isolates from different outbreaks after 45 years have revealed the genetic stability of the structural proteins of YFV which are the primary targets of the host immune cells. This probably explains why yellow fever 17D vaccine is considered as outstandingly efficacious and safe after being used for 75 years. However, the 14 amino-acid changes among these isolates may have a greater impact on the changing disease epidemiology, virulence and transmission rate. Low population immunity against YF influences outbreak frequency especially in countries where the incorporation of YF vaccination is not combined with mass vaccination campaigns or vaccination is limited to international travellers. Understanding Yellow fever virus epidemiology as determined by its evolution underscores appropriate disease mitigation strategies and immunization policies. Mobilizing scarce resources to enhance population immunity through sufficient

  20. Addressing a Yellow Fever Vaccine Shortage - United States, 2016-2017.

    PubMed

    Gershman, Mark D; Angelo, Kristina M; Ritchey, Julian; Greenberg, David P; Muhammad, Riyadh D; Brunette, Gary; Cetron, Martin S; Sotir, Mark J

    2017-05-05

    Recent manufacturing problems resulted in a shortage of the only U.S.-licensed yellow fever vaccine. This shortage is expected to lead to a complete depletion of yellow fever vaccine available for the immunization of U.S. travelers by mid-2017. CDC, the Food and Drug Administration (FDA), and Sanofi Pasteur are collaborating to ensure a continuous yellow fever vaccine supply in the United States. As part of this collaboration, Sanofi Pasteur submitted an expanded access investigational new drug (eIND) application to FDA in September 2016 to allow for the importation and use of an alternative yellow fever vaccine manufactured by Sanofi Pasteur France, with safety and efficacy comparable to the U.S.-licensed vaccine; the eIND was accepted by FDA in October 2016. The implementation of this eIND protocol included developing a systematic process for selecting a limited number of clinic sites to provide the vaccine. CDC and Sanofi Pasteur will continue to communicate with the public and other stakeholders, and CDC will provide a list of locations that will be administering the replacement vaccine at a later date.

  1. Yellow fever vaccine used in a psoriatic arthritis patient treated with methotrexate: a case report.

    PubMed

    Stuhec, Matej

    2014-01-01

    The yellow fever vaccines on the market are contraindicated for immunocompromised and elderly patients. A case of yellow fever vaccine used in a 27-year-old Slovenian male with psoriatic arthritis during treatment with methotrexate is described. We demonstrate a positive case, since there were no adverse effects in concurrent administration of yellow fever vaccine and methotrexate. This patient did not show severe adverse reactions and did not contract yellow fever despite potential exposure. More research is needed on possible adverse effects of concurrent administration of yellow fever vaccine and methotrexate to determine the potential of this method for more frequent use.

  2. Rapid molecular assays for the detection of yellow fever virus in low-resource settings.

    PubMed

    Escadafal, Camille; Faye, Oumar; Sall, Amadou Alpha; Faye, Ousmane; Weidmann, Manfred; Strohmeier, Oliver; von Stetten, Felix; Drexler, Josef; Eberhard, Michael; Niedrig, Matthias; Patel, Pranav

    2014-03-01

    Yellow fever (YF) is an acute viral hemorrhagic disease transmitted by Aedes mosquitoes. The causative agent, the yellow fever virus (YFV), is found in tropical and subtropical areas of South America and Africa. Although a vaccine is available since the 1930s, YF still causes thousands of deaths and several outbreaks have recently occurred in Africa. Therefore, rapid and reliable diagnostic methods easy to perform in low-resources settings could have a major impact on early detection of outbreaks and implementation of appropriate response strategies such as vaccination and/or vector control. The aim of this study was to develop a YFV nucleic acid detection method applicable in outbreak investigations and surveillance studies in low-resource and field settings. The method should be simple, robust, rapid and reliable. Therefore, we adopted an isothermal approach and developed a recombinase polymerase amplification (RPA) assay which can be performed with a small portable instrument and easy-to-use lyophilized reagents. The assay was developed in three different formats (real-time with or without microfluidic semi-automated system and lateral-flow assay) to evaluate their application for different purposes. Analytical specificity and sensitivity were evaluated with a wide panel of viruses and serial dilutions of YFV RNA. Mosquito pools and spiked human plasma samples were also tested for assay validation. Finally, real-time RPA in portable format was tested under field conditions in Senegal. The assay was able to detect 20 different YFV strains and demonstrated no cross-reactions with closely related viruses. The RPA assay proved to be a robust, portable method with a low detection limit (<21 genome equivalent copies per reaction) and rapid processing time (<20 min). Results from real-time RPA field testing were comparable to results obtained in the laboratory, thus confirming our method is suitable for YFV detection in low-resource settings.

  3. Rapid Molecular Assays for the Detection of Yellow Fever Virus in Low-Resource Settings

    PubMed Central

    Escadafal, Camille; Faye, Oumar; Sall, Amadou Alpha; Faye, Ousmane; Weidmann, Manfred; Strohmeier, Oliver; von Stetten, Felix; Drexler, Josef; Eberhard, Michael; Niedrig, Matthias; Patel, Pranav

    2014-01-01

    Background Yellow fever (YF) is an acute viral hemorrhagic disease transmitted by Aedes mosquitoes. The causative agent, the yellow fever virus (YFV), is found in tropical and subtropical areas of South America and Africa. Although a vaccine is available since the 1930s, YF still causes thousands of deaths and several outbreaks have recently occurred in Africa. Therefore, rapid and reliable diagnostic methods easy to perform in low-resources settings could have a major impact on early detection of outbreaks and implementation of appropriate response strategies such as vaccination and/or vector control. Methodology The aim of this study was to develop a YFV nucleic acid detection method applicable in outbreak investigations and surveillance studies in low-resource and field settings. The method should be simple, robust, rapid and reliable. Therefore, we adopted an isothermal approach and developed a recombinase polymerase amplification (RPA) assay which can be performed with a small portable instrument and easy-to-use lyophilized reagents. The assay was developed in three different formats (real-time with or without microfluidic semi-automated system and lateral-flow assay) to evaluate their application for different purposes. Analytical specificity and sensitivity were evaluated with a wide panel of viruses and serial dilutions of YFV RNA. Mosquito pools and spiked human plasma samples were also tested for assay validation. Finally, real-time RPA in portable format was tested under field conditions in Senegal. Conclusion/Significance The assay was able to detect 20 different YFV strains and demonstrated no cross-reactions with closely related viruses. The RPA assay proved to be a robust, portable method with a low detection limit (<21 genome equivalent copies per reaction) and rapid processing time (<20 min). Results from real-time RPA field testing were comparable to results obtained in the laboratory, thus confirming our method is suitable for YFV detection in

  4. [Completed sequences analysis on the Chinese attenuated yellow fever 17D vaccine strain and the WHO standard yellow fever 17D vaccine strain].

    PubMed

    Li, Jing; Yu, Yong-Xin; Dong, Guan-Mu

    2009-04-01

    To compare the molecular characteristics of the Chinese attenuated yellow fever 17D vaccine strain and the WHO reference yellow fever 17D vaccine strain. The primers were designed according to the published nucleotide sequences of YFV 17D strains in GenBank. Total RNA of was extracted by the Trizol and reverse transcripted. The each fragments of the YFV genome were amplified by PCR and sequenced subsequently. The fragments of the 5' and 3' end of the two strains were cloned into the pGEM T-easy vector and then sequenced. The nucleotide acid and amino acid sequences of the homology to both strains were 99% with each other. No obvious nulceotide changes were found in the sequences of the entire genome of each 17D strains. Moreover, there was no obvious changes in the E protein genes. But the E173 of YF17D Tiantan, associted with the virulence, had mutantions. And the two live attenuated yellow fever 17D vaccine strains fell to the same lineage by the phylogenetic analysis. The results indicated that the two attenuated yellow fever 17D vaccine viruses accumulates mutations at a very low frequency and the genomes were relative stable.

  5. Yellow Fever Virus Vaccine–associated Deaths in Young Women1

    PubMed Central

    2011-01-01

    Yellow fever vaccine–associated viscerotropic disease is a rare sequela of live-attenuated virus vaccine. Elderly persons and persons who have had thymectomies have increased susceptibility. A review of published and other data suggested a higher than expected number of deaths from yellow fever vaccine–associated viscerotropic disease among women 19–34 years of age without known immunodeficiency. PMID:22000363

  6. Duration of post-vaccination immunity to yellow fever in volunteers eight years after a dose-response study.

    PubMed

    de Menezes Martins, Reinaldo; Maia, Maria de Lourdes S; de Lima, Sheila Maria Barbosa; de Noronha, Tatiana Guimarães; Xavier, Janaina Reis; Camacho, Luiz Antonio Bastos; de Albuquerque, Elizabeth Maciel; Farias, Roberto Henrique Guedes; da Matta de Castro, Thalita; Homma, Akira

    2018-06-27

    In 2009, Bio-Manguinhos conducted a dose-response study with the yellow fever vaccine, administering the vaccine in the usual mean dose of 27,476 IU (full dose, reference) and in tapered doses (10,447 IU, 3013 IU, 587 IU, 158 IU, and 31 IU) by the usual subcutaneous route and usual volume (0.5 mL). Tapered doses were obtained by dilution in the manufacturer's laboratory, and the test batches presented industrial quality. Doses down to 587 IU showed similar immunogenicity to the full dose (27,476, reference), while the 158 IU and 31 IU doses displayed lower immunogenicity. Seropositivity was maintained at 10 months, except in the group that received the 31 IU dose. The current study aims to determine whether yellow fever seropositivity was maintained eight years after YF vaccination in non-revaccinated individuals. According to the current study's results, seropositivity was maintained in 85% of 318 participants and was similar across groups. The findings support the use of the yellow fever vaccine in fractional doses during outbreaks, but each fractional dose should have at least 587 IU. This study also supports the minimum dose required by WHO, 1000 IU. Clinicaltrials.gov NCT 03338231. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Surveillance for yellow Fever virus in non-human primates in southern Brazil, 2001-2011: a tool for prioritizing human populations for vaccination.

    PubMed

    Almeida, Marco A B; Cardoso, Jader da C; Dos Santos, Edmilson; da Fonseca, Daltro F; Cruz, Laura L; Faraco, Fernando J C; Bercini, Marilina A; Vettorello, Kátia C; Porto, Mariana A; Mohrdieck, Renate; Ranieri, Tani M S; Schermann, Maria T; Sperb, Alethéa F; Paz, Francisco Z; Nunes, Zenaida M A; Romano, Alessandro P M; Costa, Zouraide G; Gomes, Silvana L; Flannery, Brendan

    2014-03-01

    In Brazil, epizootics among New World monkey species may indicate circulation of yellow fever (YF) virus and provide early warning of risk to humans. Between 1999 and 2001, the southern Brazilian state of Rio Grande do Sul initiated surveillance for epizootics of YF in non-human primates to inform vaccination of human populations. Following a YF outbreak, we analyzed epizootic surveillance data and assessed YF vaccine coverage, timeliness of implementation of vaccination in unvaccinated human populations. From October 2008 through June 2009, circulation of YF virus was confirmed in 67 municipalities in Rio Grande do Sul State; vaccination was recommended in 23 (34%) prior to the outbreak and in 16 (24%) within two weeks of first epizootic report. In 28 (42%) municipalities, vaccination began more than two weeks after first epizootic report. Eleven (52%) of 21 laboratory-confirmed human YF cases occurred in two municipalities with delayed vaccination. By 2010, municipalities with confirmed YF epizootics reported higher vaccine coverage than other municipalities that began vaccination. In unvaccinated human populations timely response to epizootic events is critical to prevent human yellow fever cases.

  8. Yellow fever vaccine: worthy friend or stealthy foe?

    PubMed

    Seligman, Stephen J; Casanova, Jean-Laurent

    2016-06-01

    Recognition that the live yellow fever vaccine may rarely be associated with viscerotropic disease (YEL-AVD) has diminished its safety status. However, the vaccine remains the principal tool for limiting the occurrence of yellow fever, making large portions of Africa and South America more habitable. The subject has previously been exhaustively reviewed. Novel concepts in the current report include the description of a systematic method for deciding whom to vaccinate, recommendations for obtaining data helpful in making that decision, and suggestions for additional study. The vaccine is indeed a worthy friend, but its adverse reactions need to be recognized.

  9. 42 CFR 71.3 - Designation of yellow fever vaccination centers; Validation stamps.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...; Validation stamps. 71.3 Section 71.3 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN... Designation of yellow fever vaccination centers; Validation stamps. (a) Designation of yellow fever... health department, may revoke designation. (b) Validation stamps. International Certificates of...

  10. 42 CFR 71.3 - Designation of yellow fever vaccination centers; Validation stamps.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...; Validation stamps. 71.3 Section 71.3 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN... Designation of yellow fever vaccination centers; Validation stamps. (a) Designation of yellow fever... health department, may revoke designation. (b) Validation stamps. International Certificates of...

  11. 42 CFR 71.3 - Designation of yellow fever vaccination centers; Validation stamps.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...; Validation stamps. 71.3 Section 71.3 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN... Designation of yellow fever vaccination centers; Validation stamps. (a) Designation of yellow fever... health department, may revoke designation. (b) Validation stamps. International Certificates of...

  12. 42 CFR 71.3 - Designation of yellow fever vaccination centers; Validation stamps.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...; Validation stamps. 71.3 Section 71.3 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN... Designation of yellow fever vaccination centers; Validation stamps. (a) Designation of yellow fever... health department, may revoke designation. (b) Validation stamps. International Certificates of...

  13. Rift Valley fever outbreak, southern Mauritania, 2012.

    PubMed

    Sow, Abdourahmane; Faye, Ousmane; Ba, Yamar; Ba, Hampathé; Diallo, Diawo; Faye, Oumar; Loucoubar, Cheikh; Boushab, Mohamed; Barry, Yahya; Diallo, Mawlouth; Sall, Amadou Alpha

    2014-02-01

    After a period of heavy rainfall, an outbreak of Rift Valley fever occurred in southern Mauritania during September-November 2012. A total of 41 human cases were confirmed, including 13 deaths, and 12 Rift Valley fever virus strains were isolated. Moudjeria and Temchecket Departments were the most affected areas.

  14. An Atypical Local Vesicular Reaction to the Yellow Fever Vaccine.

    PubMed

    Wauters, Robert H; Hernandez, Camellia L; Petersen, Maureen M

    2017-09-19

    Yellow fever vaccine is a live attenuated viral inoculation indicated for patients traveling to endemic areas. The vaccine is generally well tolerated with minimal adverse effects. Typical side effects include malaise, pain at the injection site, and, albeit rarely, immediate hypersensitivity reactions. We present a case of a rare adverse reaction to yellow fever vaccine in which a patient developed vesicular lesions resulting in bullae and circumferential hyperpigmentation.

  15. First case of yellow fever vaccine-associated viscerotropic disease (YEL-AVD) in Hong Kong.

    PubMed

    Leung, Wai Shing; Chan, Man Chun; Chik, Shiu Hong; Tsang, Tak Yin

    2016-04-01

    Yellow fever is an important and potentially fatal infection in tropical regions of Africa, South America, eastern Panama in Central America and Trinidad in the Caribbean. Yellow fever vaccination is not only crucial to reduce the disease risk and mortality in individuals travelling to these areas, but also an important public health measure to prevent the spread of the disease. Despite generally considered as a safe vaccine, yellow fever vaccine can rarely be associated with severe adverse reactions including yellow fever vaccine-associated viscerotropic disease (YEL-AVD). Here, we report the first case of YEL-AVD in Hong Kong. Clinicians should alert to the possibility of YEL-AVD in vaccinees presenting with compatible symptoms after yellow fever vaccination, particularly in people at higher risk of adverse events. © International Society of Travel Medicine, 2016. All rights reserved. Published by Oxford University Press. For permissions, please e-mail: journals.permissions@oup.com.

  16. Seroprevalence of yellow fever virus in selected health facilities in Western Kenya from 2010 to 2012.

    PubMed

    Kwallah, Allan ole; Inoue, Shingo; Thairu-Muigai, Anne Wangari; Kuttoh, Nancy; Morita, Kouichi; Mwau, Matilu

    2015-01-01

    Yellow fever (YF), which is caused by a mosquito-borne virus, is an important viral hemorrhagic fever endemic in equatorial Africa and South America. Yellow fever virus (YFV) is the prototype of the family Flaviviridae and genus Flavivirus. The aim of this study was to determine the seroprevalence of YFV in selected health facilities in Western Kenya during the period 2010-2012. A total of 469 serum samples from febrile patients were tested for YFV antibodies using in-house IgM-capture ELISA, in-house indirect IgG ELISA, and 50% focus reduction neutralization test (FRNT50). The present study did not identify any IgM ELISA-positive cases, indicating absence of recent YFV infection in the area. Twenty-eight samples (6%) tested positive for YFV IgG, because of either YFV vaccination or past exposure to various flaviviruses including YFV. Five cases were confirmed by FRNT50; of these, 4 were either vaccination or natural infection during the YF outbreak in 1992-1993 or another period and 1 case was confirmed as a West Nile virus infection. Domestication and routine performance of arboviral differential diagnosis will help to address the phenomenon of pyrexia of unknown origin, contribute to arboviral research in developing countries, and enhance regular surveillance.

  17. Demographic profile of sylvatic yellow fever in Brazil from 1973 to 2008.

    PubMed

    Câmara, Fernando Portela; de Carvalho, Luiz Max; Gomes, Ana Luisa Bacellar

    2013-05-01

    Yellow fever is an acute, frequently fatal, febrile arbovirosis that in Brazil occurs only in the sylvatic form. Sylvatic yellow fever (SYF) appears in sporadic outbreaks over a large area of Brazil. In this paper, we analyze the demographic profile of 831 SYF cases that occurred between 1973 and 2008, to determine which segments of the exposed population are at greater risk. Data were statistically analyzed and were also geo-referenced in order to observe their spatial pattern. The basic reproductive number of infections, R0, was estimated by the ratio between average life expectancy and the average age of the cases. SYF cases showed a modal profile of young male adults, approximately 30 years of age, living in rural areas of the states of Pará, Goiás, Maranhão and Minas Gerais, who were unvaccinated or whose vaccination was out of date. The disease showed a high mortality rate (51%, 421/831) among the notified cases, with death occurring on around the seventh day of illness for most patients. The R0 for SYF was estimated at approximately 2.4. The results of this study suggest that lack of vaccination coverage is a major risk factor for SYF, and that the groups most at risk are migrant laborers, farm workers and tourists.

  18. Development of a Real-Time Reverse Transcription-PCR Assay for Global Differentiation of Yellow Fever Virus Vaccine-Related Adverse Events from Natural Infections.

    PubMed

    Hughes, Holly R; Russell, Brandy J; Mossel, Eric C; Kayiwa, John; Lutwama, Julius; Lambert, Amy J

    2018-06-01

    Yellow fever (YF) is a reemerging public health threat, with frequent outbreaks prompting large vaccination campaigns in regions of endemicity in Africa and South America. Specific detection of vaccine-related adverse events is resource-intensive, time-consuming, and difficult to achieve during an outbreak. To address this, we have developed a highly transferable rapid yellow fever virus (YFV) vaccine-specific real-time reverse transcription-PCR (RT-PCR) assay that distinguishes vaccine from wild-type lineages. The assay utilizes a specific hydrolysis probe that includes locked nucleic acids to enhance specific discrimination of the YFV17D vaccine strain genome. Promisingly, sensitivity and specificity analyses reveal this assay to be highly specific to vaccine strain(s) when tested on clinical samples and YFV cell culture isolates of global origin. Taken together, our data suggest the utility of this assay for use in laboratories of varied capacity for the identification and differentiation of vaccine-related adverse events from wild-type infections of both African and South American origin. Copyright © 2018 American Society for Microbiology.

  19. Adaptive immune responses to booster vaccination against yellow fever virus are much reduced compared to those after primary vaccination.

    PubMed

    Kongsgaard, Michael; Bassi, Maria R; Rasmussen, Michael; Skjødt, Karsten; Thybo, Søren; Gabriel, Mette; Hansen, Morten Bagge; Christensen, Jan Pravsgaard; Thomsen, Allan Randrup; Buus, Soren; Stryhn, Anette

    2017-04-06

    Outbreaks of Yellow Fever occur regularly in endemic areas of Africa and South America frequently leading to mass vaccination campaigns straining the availability of the attenuated Yellow Fever vaccine, YF-17D. The WHO has recently decided to discontinue regular booster-vaccinations since a single vaccination is deemed to confer life-long immune protection. Here, we have examined humoral (neutralizing antibody) and cellular (CD8 and CD4 T cell) immune responses in primary and booster vaccinees (the latter spanning 8 to 36 years after primary vaccination). After primary vaccination, we observed strong cellular immune responses with T cell activation peaking ≈2 weeks and subsiding to background levels ≈ 4 weeks post-vaccination. The number of antigen-specific CD8+ T cells declined over the following years. In >90% of vaccinees, in vitro expandable T cells could still be detected >10 years post-vaccination. Although most vaccinees responded to a booster vaccination, both the humoral and cellular immune responses observed following booster vaccination were strikingly reduced compared to primary responses. This suggests that pre-existing immunity efficiently controls booster inoculums of YF-17D. In a situation with epidemic outbreaks, one could argue that a more efficient use of a limited supply of the vaccine would be to focus on primary vaccinations.

  20. Advanced yellow fever virus genome detection in point-of-care facilities and reference laboratories.

    PubMed

    Domingo, Cristina; Patel, Pranav; Yillah, Jasmin; Weidmann, Manfred; Méndez, Jairo A; Nakouné, Emmanuel Rivalyn; Niedrig, Matthias

    2012-12-01

    Reported methods for the detection of the yellow fever viral genome are beset by limitations in sensitivity, specificity, strain detection spectra, and suitability to laboratories with simple infrastructure in areas of endemicity. We describe the development of two different approaches affording sensitive and specific detection of the yellow fever genome: a real-time reverse transcription-quantitative PCR (RT-qPCR) and an isothermal protocol employing the same primer-probe set but based on helicase-dependent amplification technology (RT-tHDA). Both assays were evaluated using yellow fever cell culture supernatants as well as spiked and clinical samples. We demonstrate reliable detection by both assays of different strains of yellow fever virus with improved sensitivity and specificity. The RT-qPCR assay is a powerful tool for reference or diagnostic laboratories with real-time PCR capability, while the isothermal RT-tHDA assay represents a useful alternative to earlier amplification techniques for the molecular diagnosis of yellow fever by field or point-of-care laboratories.

  1. Molecular characterization of the 2011 Hong Kong scarlet fever outbreak.

    PubMed

    Tse, Herman; Bao, Jessie Y J; Davies, Mark R; Maamary, Peter; Tsoi, Hoi-Wah; Tong, Amy H Y; Ho, Tom C C; Lin, Chi-Ho; Gillen, Christine M; Barnett, Timothy C; Chen, Jonathan H K; Lee, Mianne; Yam, Wing-Cheong; Wong, Chi-Kin; Ong, Cheryl-Lynn Y; Chan, Yee-Wai; Wu, Cheng-Wei; Ng, Tony; Lim, Wilina W L; Tsang, Thomas H F; Tse, Cindy W S; Dougan, Gordon; Walker, Mark J; Lok, Si; Yuen, Kwok-Yung

    2012-08-01

    A scarlet fever outbreak occurred in Hong Kong in 2011. The majority of cases resulted in the isolation of Streptococcus pyogenes emm12 with multiple antibiotic resistances. Phylogenetic analysis of 22 emm12 scarlet fever outbreak isolates, 7 temporally and geographically matched emm12 non-scarlet fever isolates, and 18 emm12 strains isolated during 2005-2010 indicated the outbreak was multiclonal. Genome sequencing of 2 nonclonal scarlet fever isolates (HKU16 and HKU30), coupled with diagnostic polymerase chain reaction assays, identified 2 mobile genetic elements distributed across the major lineages: a 64.9-kb integrative and conjugative element encoding tetracycline and macrolide resistance and a 46.4-kb prophage encoding superantigens SSA and SpeC and the DNase Spd1. Phenotypic comparison of HKU16 and HKU30 with the S. pyogenes M1T1 strain 5448 revealed that HKU16 displays increased adherence to HEp-2 human epithelial cells, whereas HKU16, HKU30, and 5448 exhibit equivalent resistance to neutrophils and virulence in a humanized plasminogen murine model. However, in contrast to M1T1, the virulence of HKU16 and HKU30 was not associated with covRS mutation. The multiclonal nature of the emm12 scarlet fever isolates suggests that factors such as mobile genetic elements, environmental factors, and host immune status may have contributed to the 2011 scarlet fever outbreak.

  2. STUDIES ON YELLOW FEVER IN SOUTH AMERICA

    PubMed Central

    Davis, Nelson C.; Shannon, Raymond C.

    1929-01-01

    1. Yellow fever virus has been transmitted from monkey to monkey both by the bites of Aëdes (Ochlerotatus) scapularis which had fed upon monkeys infected with yellow fever and by the injection of the ground up bodies of such mosquitoes. 2. A fatal infection has been obtained by the injection of the ground up bodies of Aëdes (Ochlerotatus) serratus, which had previously fed on an infected monkey, and a mild infection has been secured by the similar injection of Aëdes (Taeniorhynchus) taeniorhynchus. 3. No definite infection has been secured either by the bites or by the injection of Culex quinquefasciatus (C. fatigans). However, some of the experimental animals bitten by this species have been relatively immune following inoculations of blood or tissues containing virus. PMID:19869666

  3. An inactivated cell-culture vaccine against yellow fever.

    PubMed

    Monath, Thomas P; Fowler, Elizabeth; Johnson, Casey T; Balser, John; Morin, Merribeth J; Sisti, Maggie; Trent, Dennis W

    2011-04-07

    Yellow fever is a lethal viral hemorrhagic fever occurring in Africa and South America. A highly effective live vaccine (17D) is widely used for travelers to and residents of areas in which yellow fever is endemic, but the vaccine can cause serious adverse events, including viscerotropic disease, which is associated with a high rate of death. A safer, nonreplicating vaccine is needed. In a double-blind, placebo-controlled, dose-escalation, phase 1 study of 60 healthy subjects between 18 and 49 years of age, we investigated the safety and immunogenicity of XRX-001 purified whole-virus, β-propiolactone-inactivated yellow fever vaccine produced in Vero cell cultures and adsorbed to aluminum hydroxide (alum) adjuvant. On two visits 21 days apart, subjects received intramuscular injections of vaccine that contained 0.48 μg or 4.8 μg of antigen. Levels of neutralizing antibodies were measured at baseline and on days 21, 31, and 42. The vaccine induced the development of neutralizing antibodies in 100% of subjects receiving 4.8 μg of antigen in each injection and in 88% of subjects receiving 0.48 μg of antigen in each injection. Antibody levels increased by day 10 after the second injection, at which time levels were significantly higher with the 4.8-μg formulation than with the 0.48-μg formulation (geometric mean titer, 146 vs. 39; P<0.001). Three adverse events occurred at a higher incidence in the two vaccine groups than in the placebo group: mild pain, tenderness, and (much less frequently) itching at the injection site. One case of urticaria was observed on day 3 after the second dose of 4.8 μg of vaccine. A two-dose regimen of the XRX-001 vaccine, containing inactivated yellow fever antigen with an alum adjuvant, induced neutralizing antibodies in a high percentage of subjects. XRX-001 has the potential to be a safer alternative to live attenuated 17D vaccine. (Funded by Xcellerex; ClinicalTrials.gov number, NCT00995865.).

  4. Fractional dosing of yellow fever vaccine to extend supply: a modelling study.

    PubMed

    Wu, Joseph T; Peak, Corey M; Leung, Gabriel M; Lipsitch, Marc

    2016-12-10

    The ongoing yellow fever epidemic in Angola strains the global vaccine supply, prompting WHO to adopt dose sparing for its vaccination campaign in Kinshasa, Democratic Republic of the Congo, in July-August, 2016. Although a 5-fold fractional-dose vaccine is similar to standard-dose vaccine in safety and immunogenicity, efficacy is untested. There is an urgent need to ensure the robustness of fractional-dose vaccination by elucidation of the conditions under which dose fractionation would reduce transmission. We estimate the effective reproductive number for yellow fever in Angola using disease natural history and case report data. With simple mathematical models of yellow fever transmission, we calculate the infection attack rate (the proportion of population infected over the course of an epidemic) with various levels of transmissibility and 5-fold fractional-dose vaccine efficacy for two vaccination scenarios, ie, random vaccination in a hypothetical population that is completely susceptible, and the Kinshasa vaccination campaign in July-August, 2016, with different age cutoff for fractional-dose vaccines. We estimate the effective reproductive number early in the Angola outbreak was between 5·2 and 7·1. If vaccine action is all-or-nothing (ie, a proportion of vaccine recipients receive complete protection [VE] and the remainder receive no protection), n-fold fractionation can greatly reduce infection attack rate as long as VE exceeds 1/n. This benefit threshold becomes more stringent if vaccine action is leaky (ie, the susceptibility of each vaccine recipient is reduced by a factor that is equal to the vaccine efficacy). The age cutoff for fractional-dose vaccines chosen by WHO for the Kinshasa vaccination campaign (2 years) provides the largest reduction in infection attack rate if the efficacy of 5-fold fractional-dose vaccines exceeds 20%. Dose fractionation is an effective strategy for reduction of the infection attack rate that would be robust with a

  5. VACCINATION AGAINST YELLOW FEVER WITH IMMUNE SERUM AND VIRUS FIXED FOR MICE

    PubMed Central

    Sawyer, W. A.; Kitchen, S. F.; Lloyd, Wray

    1932-01-01

    1. After preliminary experiments in monkeys, 15 persons were actively immunized by a single injection of a dried mixture of living yellow fever virus, fixed for mice, and human immune serum, with separate injections of enough additional serum to make up the amount required for protection. 2. One person was similarly immunized by injecting immune serum and dried virus separately. 3. By titration of the sera of vaccinated persons in mice, it was shown that the immunity rose in a few weeks to a height comparable to that reached after an attack of yellow fever, and remained there throughout an observation period of 6 months. 4. Yellow fever virus could not be recovered from the blood of vaccinated persons or monkeys, except when the latter had received less than the minimal effective amount of immune serum. 5. Neutralization of yellow fever virus by immune serum took place very slowly in vitro at room temperature in our experiments, and could not have been an appreciable factor in vaccination with the serum virus mixtures. 6. A mixture of fixed virus and immune serum retained its immunizing power for 8 months when dried in the frozen state and sealed in glass. 7. It appears that the immunizing reaction after yellow fever vaccination was a part of a true infectious process, as was also the observed leucopenia. PMID:19870044

  6. Oral receptivity of Aedes aegypti from Cape Verde for yellow fever, dengue, and chikungunya viruses.

    PubMed

    Vazeille, Marie; Yébakima, André; Lourenço-de-Oliveira, Ricardo; Andriamahefazafy, Barrysson; Correira, Artur; Rodrigues, Julio Monteiro; Veiga, Antonio; Moreira, Antonio; Leparc-Goffart, Isabelle; Grandadam, Marc; Failloux, Anna-Bella

    2013-01-01

    At the end of 2009, 21,313 cases of dengue-3 virus (DENV-3) were reported in the islands of Cape Verde, an archipelago located in the Atlantic Ocean 570 km from the coast of western Africa. It was the first dengue outbreak ever reported in Cape Verde. Mosquitoes collected in July 2010 in the city of Praia, on the island of Santiago, were identified morphologically as Aedes aegypti formosus. Using experimental oral infections, we found that this vector showed a moderate ability to transmit the epidemic dengue-3 virus, but was highly susceptible to chikungunya and yellow fever viruses.

  7. Molecular Characterization of the 2011 Hong Kong Scarlet Fever Outbreak

    PubMed Central

    Tse, Herman; Bao, Jessie Y. J.; Davies, Mark R.; Maamary, Peter; Tsoi, Hoi-Wah; Tong, Amy H. Y.; Ho, Tom C. C.; Lin, Chi-Ho; Gillen, Christine M.; Barnett, Timothy C.; Chen, Jonathan H. K.; Lee, Mianne; Yam, Wing-Cheong; Wong, Chi-Kin; Ong, Cheryl-lynn Y.; Chan, Yee-Wai; Wu, Cheng-Wei; Ng, Tony; Lim, Wilina W. L.; Tsang, Thomas H. F.; Tse, Cindy W. S.; Dougan, Gordon; Walker, Mark J.; Lok, Si; Yuen, Kwok-Yung

    2012-01-01

    A scarlet fever outbreak occurred in Hong Kong in 2011. The majority of cases resulted in the isolation of Streptococcus pyogenes emm12 with multiple antibiotic resistances. Phylogenetic analysis of 22 emm12 scarlet fever outbreak isolates, 7 temporally and geographically matched emm12 non–scarlet fever isolates, and 18 emm12 strains isolated during 2005–2010 indicated the outbreak was multiclonal. Genome sequencing of 2 nonclonal scarlet fever isolates (HKU16 and HKU30), coupled with diagnostic polymerase chain reaction assays, identified 2 mobile genetic elements distributed across the major lineages: a 64.9-kb integrative and conjugative element encoding tetracycline and macrolide resistance and a 46.4-kb prophage encoding superantigens SSA and SpeC and the DNase Spd1. Phenotypic comparison of HKU16 and HKU30 with the S. pyogenes M1T1 strain 5448 revealed that HKU16 displays increased adherence to HEp-2 human epithelial cells, whereas HKU16, HKU30, and 5448 exhibit equivalent resistance to neutrophils and virulence in a humanized plasminogen murine model. However, in contrast to M1T1, the virulence of HKU16 and HKU30 was not associated with covRS mutation. The multiclonal nature of the emm12 scarlet fever isolates suggests that factors such as mobile genetic elements, environmental factors, and host immune status may have contributed to the 2011 scarlet fever outbreak. PMID:22615319

  8. The First Prediction of a Rift Valley Fever Outbreak

    NASA Technical Reports Server (NTRS)

    Anyamba, Assaf; Chretien, Jean-Paul; Small, Jennifer; Tucker, Compton J.; Formenty, Pierre; Richardson, Jason H.; Britch, Seth C.; Schnabel, David C.; Erickson, Ralph L.; Linthicum, Kenneth J.

    2009-01-01

    El Nino/Southern Oscillation (ENSO) related anomalies were analyzed using a combination of satellite measurements of elevated sea surface temperatures, and subsequent elevated rainfall and satellite derived normalized difference vegetation index data. A Rift Valley fever risk mapping model using these climate data predicted areas where outbreaks of Rift Valley fever in humans and animals were expected and occurred in the Horn of Africa from December 2006 to May 2007. The predictions were subsequently confirmed by entomological and epidemiological field investigations of virus activity in the areas identified as at risk. Accurate spatial and temporal predictions of disease activity, as it occurred first in southern Somalia and then through much of Kenya before affecting northern Tanzania, provided a 2 to 6 week period of warning for the Horn of Africa that facilitated disease outbreak response and mitigation activities. This is the first prospective prediction of a Rift Valley fever outbreak.

  9. Development of a reverse transcription polymerase chain reaction method for yellow fever virus detection.

    PubMed

    Méndez, María C; Domingo, Cristina; Tenorio, Antonio; Pardo, Lissethe C; Rey, Gloria J; Méndez, Jairo A

    2013-09-01

    Yellow fever is considered a re-emerging disease and is endemic in tropical regions of Africa and South America. At present, there are no standardized or commercialized kits available for yellow fever virus detection. Therefore, diagnosis must be made by time-consuming routine techniques, and sometimes, the virus or its proteins are not detected. Furthermore, co-circulation with other flaviviruses, including dengue virus, increases the difficulty of diagnosis. To develop a specific reverse transcriptase-polymerase chain reaction (RT-PCR) and nested PCR-based assay to improve the detection and diagnosis of yellow fever virus using both serum and fresh tissue samples. RT-PCR primers were designed to amplify a short fragment of all yellow fever virus genotypes reported. A second set of primers was used in a nested PCR to increase sensitivity. Thirty-three clinical samples were tested with the standardized reaction. The expected amplicon was obtained in 25 out of 33 samples analyzed using this approach, and 2 more samples tested positive after a subsequent nested PCR approach. This improved technique not only ensures the specific detection of a wide range of yellow fever virus genotypes but also may increase the sensitivity of detection by introducing a second round of amplification, allowing a rapid differential diagnosis between dengue and yellow fever infection, which is required for effective surveillance and opportune epidemiologic measures.

  10. Enzootic transmission of yellow fever virus, Venezuela.

    PubMed

    Auguste, Albert J; Lemey, Philippe; Bergren, Nicholas A; Giambalvo, Dileyvic; Moncada, Maria; Morón, Dulce; Hernandez, Rosa; Navarro, Juan-Carlos; Weaver, Scott C

    2015-01-01

    Phylogenetic analysis of yellow fever virus (YFV) strains isolated from Venezuela strongly supports YFV maintenance in situ in Venezuela, with evidence of regionally independent evolution within the country. However, there is considerable YFV movement from Brazil to Venezuela and between Trinidad and Venezuela.

  11. The phylogeny of yellow fever virus 17D vaccines.

    PubMed

    Stock, Nina K; Boschetti, Nicola; Herzog, Christian; Appelhans, Marc S; Niedrig, Matthias

    2012-02-01

    In recent years the safety of the yellow fever live vaccine 17D came under scrutiny. The focus was on serious adverse events after vaccinations that resemble a wild type infection with yellow fever and whose reasons are still not known. Also the exact mechanism of attenuation of the vaccine remains unknown to this day. In this context, the standards of safety and surveillance in vaccine production and administration have been discussed. Therein embodied was the demand for improved documentation of the derivation of the seed virus used for yellow fever vaccine production. So far, there was just a historical genealogy available that is based on source area and passage level. However, there is a need for a documentation based on molecular information to get better insights into the mechanisms of pathology. In this work we sequenced the whole genome of different passages of the YFV-17D strain used by Crucell Switzerland AG for vaccine production. Using all other publically available 17D full genome sequences we compared the sequence variance of all vaccine strains and oppose a phylogenetic tree based on full genome sequences to the historical genealogy. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Investigation of a possible yellow fever epidemic and serosurvey for flavivirus infections in northern Cameroon, 1984

    PubMed Central

    Tsai, T. F.; Lazuick, J. S.; Ngah, R. W.; Mafiamba, P. C.; Quincke, G.; Monath, T. P.

    1987-01-01

    A cluster of fatal hepatitis cases in northern Cameroon in 1984 stimulated a field investigation to rule out an epidemic of yellow fever. A serosurvey of villages in the extreme north of the country, in a Sudan savanna (SS) phytogeographical zone, disclosed no evidence of recent yellow fever infection. However, further south, in a Guinea savanna (GS) phytogeographical zone, serological evidence was found of endemic yellow fever virus transmission. The results indicate a potential for epidemic spread of yellow fever virus from the southern GS zone to the nothern SS zone of Cameroon, where immunity in the population was low. PMID:3501739

  13. Investigation of a possible yellow fever epidemic and serosurvey for flavivirus infections in northern Cameroon, 1984.

    PubMed

    Tsai, T F; Lazuick, J S; Ngah, R W; Mafiamba, P C; Quincke, G; Monath, T P

    1987-01-01

    A cluster of fatal hepatitis cases in northern Cameroon in 1984 stimulated a field investigation to rule out an epidemic of yellow fever. A serosurvey of villages in the extreme north of the country, in a Sudan savanna (SS) phytogeographical zone, disclosed no evidence of recent yellow fever infection. However, further south, in a Guinea savanna (GS) phytogeographical zone, serological evidence was found of endemic yellow fever virus transmission. The results indicate a potential for epidemic spread of yellow fever virus from the southern GS zone to the nothern SS zone of Cameroon, where immunity in the population was low.

  14. A fatal yellow fever virus infection in China: description and lessons

    PubMed Central

    Chen, Zhihai; Liu, Lin; Lv, Yanning; Zhang, Wei; Li, Jiandong; Zhang, Yi; Di, Tian; Zhang, Shuo; Liu, Jingyuan; Li, Jie; Qu, Jing; Hua, Wenhao; Li, Chuan; Wang, Peng; Zhang, Quanfu; Xu, Yanli; Jiang, Rongmeng; Wang, Qin; Chen, Lijuan; Wang, Shiwen; Pang, Xinghuo; Liang, Mifang; Ma, Xuejun; Li, Xingwang; Wang, Quanyi; Zhang, Fujie; Li, Dexin

    2016-01-01

    Yellow fever (YF) is a viral disease endemic to the tropical regions of Africa and South America. An outbreak of YF has been occurring in Angola, since the beginning of 2016. In March 2016, a 32-year-old Chinese man who returned from Angola was hospitalized and diagnosed with the first case of imported YF in China. Clinical observations, blood viral RNA detection, serological testing and treatments for the patient were performed daily. The virus was isolated in Vero cells, and the complete viral genome was sequenced and analyzed using the next-generation genomic sequencing platform. The patient presented with hemorrhagic fever, jaundice and oliguria at day 3 after onset, which rapidly progressed to multisystem organ failure with extremely elevated liver, pancreatic and myocardial enzymes. The patient died despite the intensive supportive treatments that were performed. A liver biopsy showed severe and multilobular necrosis. Viral RNA was detectable throughout the clinical course of the disease. Whole-genomic sequence analysis revealed that the virus belongs to the Angola71 genotype. Although the virus has been circulating in Angola for 45 years, only 14 amino-acid substitutions and no amino-acid changes were observed in the membrane and envelope proteins compared with the virus collected in 1971. The presence of this imported YF case in China indicated that with the increase in business travel among countries, YF outbreaks in Africa can lead to the international spread of the disease. The production and use of YF vaccines is, therefore, an urgent issue. PMID:27406389

  15. A fatal yellow fever virus infection in China: description and lessons.

    PubMed

    Chen, Zhihai; Liu, Lin; Lv, Yanning; Zhang, Wei; Li, Jiandong; Zhang, Yi; Di, Tian; Zhang, Shuo; Liu, Jingyuan; Li, Jie; Qu, Jing; Hua, Wenhao; Li, Chuan; Wang, Peng; Zhang, Quanfu; Xu, Yanli; Jiang, Rongmeng; Wang, Qin; Chen, Lijuan; Wang, Shiwen; Pang, Xinghuo; Liang, Mifang; Ma, Xuejun; Li, Xingwang; Wang, Quanyi; Zhang, Fujie; Li, Dexin

    2016-07-13

    Yellow fever (YF) is a viral disease endemic to the tropical regions of Africa and South America. An outbreak of YF has been occurring in Angola, since the beginning of 2016. In March 2016, a 32-year-old Chinese man who returned from Angola was hospitalized and diagnosed with the first case of imported YF in China. Clinical observations, blood viral RNA detection, serological testing and treatments for the patient were performed daily. The virus was isolated in Vero cells, and the complete viral genome was sequenced and analyzed using the next-generation genomic sequencing platform. The patient presented with hemorrhagic fever, jaundice and oliguria at day 3 after onset, which rapidly progressed to multisystem organ failure with extremely elevated liver, pancreatic and myocardial enzymes. The patient died despite the intensive supportive treatments that were performed. A liver biopsy showed severe and multilobular necrosis. Viral RNA was detectable throughout the clinical course of the disease. Whole-genomic sequence analysis revealed that the virus belongs to the Angola71 genotype. Although the virus has been circulating in Angola for 45 years, only 14 amino-acid substitutions and no amino-acid changes were observed in the membrane and envelope proteins compared with the virus collected in 1971. The presence of this imported YF case in China indicated that with the increase in business travel among countries, YF outbreaks in Africa can lead to the international spread of the disease. The production and use of YF vaccines is, therefore, an urgent issue.

  16. Surveillance for Yellow Fever Virus in Non-Human Primates in Southern Brazil, 2001–2011: A Tool for Prioritizing Human Populations for Vaccination

    PubMed Central

    Almeida, Marco A. B.; Cardoso, Jader da C.; dos Santos, Edmilson; da Fonseca, Daltro F.; Cruz, Laura L.; Faraco, Fernando J. C.; Bercini, Marilina A.; Vettorello, Kátia C.; Porto, Mariana A.; Mohrdieck, Renate; Ranieri, Tani M. S.; Schermann, Maria T.; Sperb, Alethéa F.; Paz, Francisco Z.; Nunes, Zenaida M. A.; Romano, Alessandro P. M.; Costa, Zouraide G.; Gomes, Silvana L.; Flannery, Brendan

    2014-01-01

    In Brazil, epizootics among New World monkey species may indicate circulation of yellow fever (YF) virus and provide early warning of risk to humans. Between 1999 and 2001, the southern Brazilian state of Rio Grande do Sul initiated surveillance for epizootics of YF in non-human primates to inform vaccination of human populations. Following a YF outbreak, we analyzed epizootic surveillance data and assessed YF vaccine coverage, timeliness of implementation of vaccination in unvaccinated human populations. From October 2008 through June 2009, circulation of YF virus was confirmed in 67 municipalities in Rio Grande do Sul State; vaccination was recommended in 23 (34%) prior to the outbreak and in 16 (24%) within two weeks of first epizootic report. In 28 (42%) municipalities, vaccination began more than two weeks after first epizootic report. Eleven (52%) of 21 laboratory-confirmed human YF cases occurred in two municipalities with delayed vaccination. By 2010, municipalities with confirmed YF epizootics reported higher vaccine coverage than other municipalities that began vaccination. In unvaccinated human populations timely response to epizootic events is critical to prevent human yellow fever cases. PMID:24625681

  17. THE TRANSMISSION OF NEUROTROPIC YELLOW FEVER VIRUS BY STEGOMYIA MOSQUITOES

    PubMed Central

    Davis, Nelson C.; Lloyd, Wray; Frobisher, Martin

    1932-01-01

    1. By the bites of stegomyia mosquitoes carrying neurotropic yellow fever virus, encephalitis has been produced both in white mice and in rhesus monkeys. 2. The fixed neurotropic strain of virus cannot be maintained in the mosquito host as well as can the viscerotropic strains. This is doubtless attributable in part to a smaller amount of virus ingested, because of paucity in the blood stream of the mammalian host. 3. These experiments furnish additional evidence that the long established neurotropic yellow fever virus has changed fundamentally from the parent French strain. PMID:19870108

  18. Enzootic Transmission of Yellow Fever Virus, Venezuela

    PubMed Central

    Auguste, Albert J.; Lemey, Philippe; Bergren, Nicholas A.; Giambalvo, Dileyvic; Moncada, Maria; Morón, Dulce; Hernandez, Rosa; Navarro, Juan-Carlos

    2015-01-01

    Phylogenetic analysis of yellow fever virus (YFV) strains isolated from Venezuela strongly supports YFV maintenance in situ in Venezuela, with evidence of regionally independent evolution within the country. However, there is considerable YFV movement from Brazil to Venezuela and between Trinidad and Venezuela. PMID:25531105

  19. [YEL-AND meningoencephalitis in a 4-year-old boy consecutive to a yellow-fever vaccine].

    PubMed

    Gerin, M; Wroblewski, I; Bost-Bru, C; N'guyen, M-A; Debillon, T

    2014-04-01

    Yellow fever is a vector-borne disease transmitted by an endemic mosquito in sub-Saharan Africa and tropical South America. It causes fever and possibly liver and renal failure with hemorrhagic signs, which may be fatal. The yellow-fever vaccine is an attenuated vaccine that is recommended for all travelers over the age of 9 months in high-risk areas. Adverse effects have been reported: minor symptoms (such as viral syndrome), hypersensitivity reactions, and major symptoms such as viscerotropic disease (YEL-AVD) and neurotropic disease (YEL-AND). The yellow-fever vaccine-associated autoimmune disease with central nervous system involvement (such as acute disseminated encephalomyelitis) associates fever and headaches, neurologic dysfunction, seizures, cerebrospinal fluid (CSF) pleocytosis, and elevated protein, with neuroimaging consistent with multifocal areas of demyelization. The presence of antibodies or virus in CSF, within 1-30 days following vaccination, and the exclusion of other causes is necessary for diagnosis. We describe herein the case of a 4-year-old child who presented with severe encephalitis consecutive to a yellow-fever vaccine, with favorable progression. Diagnosis is based on the chronology of clinical and paraclinical signs and the presence of yellow-fever-specific antibodies in CSF. The treatment consists of symptomatic treatment and immunoglobulin injection. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  20. Identification of insecticidal principals from cucumber seed oil against the yellow fever mosquito, Aedes aegypti

    USDA-ARS?s Scientific Manuscript database

    The yellow fever mosquito, Aedes aegypti, is one of the most medically important mosquito species due to its ability to spread viruses of yellow fever, dengue fever and Zika in humans. In this study, the insecticidal activity of seventeen plant essential oils were evaluated to toxicity by topical a...

  1. Diagnostic schemes for reducing epidemic size of African viral hemorrhagic fever outbreaks.

    PubMed

    Okeke, Iruka N; Manning, Robert S; Pfeiffer, Thomas

    2014-09-12

    Viral hemorrhagic fever (VHF) outbreaks, with high mortality rates, have often been amplified in African health institutions due to person-to-person transmission via infected body fluids.  By collating and analyzing epidemiological data from documented outbreaks, we observed that diagnostic delay contributes to epidemic size for Ebola and Marburg hemorrhagic fever outbreaks. We used a susceptible-exposed-infectious-removed (SEIR) model and data from the 1995 outbreak in Kikwit, Democratic Republic of Congo, to simulate Ebola hemorrhagic fever epidemics. Our model allows us to describe the dynamics for hospital staff separately from that for the general population, and to implement health worker-specific interventions. The model illustrates that implementing World Health Organization/US Centers for Disease Control and Prevention guidelines of isolating patients who do not respond to antimalarial and antibacterial chemotherapy reduces total outbreak size, from a median of 236, by 90% or more. Routinely employing diagnostic testing in post-mortems of patients that died of refractory fevers reduces the median outbreak size by a further 60%. Even greater reductions in outbreak size were seen when all febrile patients were tested for endemic infections or when febrile health-care workers were tested.  The effect of testing strategies was not impaired by the 1-3 day delay that would occur if testing were performed by a reference laboratory. In addition to improving the quality of care for common causes of febrile infections, increased and strategic use of laboratory diagnostics for fever could reduce the chance of hospital amplification of VHFs in resource-limited African health systems.

  2. Investigation of Scarlet Fever Outbreak in a Kindergarten.

    PubMed

    Ryu, Sukhyun; Chun, Byung Chul

    2018-03-01

    Scarlet fever is caused by a group A streptococcal (GAS) infection. On April 3, 2017, an outbreak among children in a kindergarten was reported to the local health department. An epidemiologic investigation was conducted to identify the possible transmission route of this outbreak and to recommend appropriate control measures. A retrospective cohort study was conducted using questionnaires including age, sex, the classroom attended at a kindergarten, and date and type of symptoms developed. A case-patient is defined as a child having sore throat, fever, skin rash, or strawberry tongue with or without laboratory confirmation of GAS infection between March 28 and April 28, 2017. The index case-patients developed symptoms on March 28, 2017, and this outbreak persisted over a period of 16 days. The outbreak affected 21 out of 158 children (13.3%) in the kindergarten, with the mean age of 4.2 (range 3-5) years; 12 (57.1%) of them were boys. The common symptoms reported were fever (71.4%), sore throat (71.4%), reddened tonsil (57.1%), and skin rash (52.4%). The epidemiologic analysis showed that children attending one of the classrooms in the kindergarten were 14.12 times affected than the other classrooms (relative risk, 14.12; 95% confidence interval, 4.99-33.93; P <0.01). All case-patients were recommended to stay away from the kindergarten and its social activities for >24 hours after starting appropriate antibiotic treatment, and all the children in the kindergarten were instructed to keep strict personal hygiene practices. Our results suggest that the outbreak likely affected from the index case-patients who attended to one of the classrooms in the kindergarten. This highlights the importance of immediate notification of outbreak to prevent large number of patients. Copyright © 2018 by The Korean Society of Infectious Diseases and Korean Society for Chemotherapy.

  3. Investigation of Scarlet Fever Outbreak in a Kindergarten

    PubMed Central

    2018-01-01

    Background Scarlet fever is caused by a group A streptococcal (GAS) infection. On April 3, 2017, an outbreak among children in a kindergarten was reported to the local health department. An epidemiologic investigation was conducted to identify the possible transmission route of this outbreak and to recommend appropriate control measures. Materials and Methods A retrospective cohort study was conducted using questionnaires including age, sex, the classroom attended at a kindergarten, and date and type of symptoms developed. A case-patient is defined as a child having sore throat, fever, skin rash, or strawberry tongue with or without laboratory confirmation of GAS infection between March 28 and April 28, 2017. Results The index case-patients developed symptoms on March 28, 2017, and this outbreak persisted over a period of 16 days. The outbreak affected 21 out of 158 children (13.3%) in the kindergarten, with the mean age of 4.2 (range 3–5) years; 12 (57.1%) of them were boys. The common symptoms reported were fever (71.4%), sore throat (71.4%), reddened tonsil (57.1%), and skin rash (52.4%). The epidemiologic analysis showed that children attending one of the classrooms in the kindergarten were 14.12 times affected than the other classrooms (relative risk, 14.12; 95% confidence interval, 4.99–33.93; P <0.01). All case-patients were recommended to stay away from the kindergarten and its social activities for >24 hours after starting appropriate antibiotic treatment, and all the children in the kindergarten were instructed to keep strict personal hygiene practices. Conclusion Our results suggest that the outbreak likely affected from the index case-patients who attended to one of the classrooms in the kindergarten. This highlights the importance of immediate notification of outbreak to prevent large number of patients. PMID:29637751

  4. Yellow fever in a traveller returning from Suriname to the Netherlands, March 2017

    PubMed Central

    Wouthuyzen-Bakker, Marjan; Knoester, Marjolein; van den Berg, Aad P; GeurtsvanKessel, Corine H; Koopmans, Marion PG; Van Leer-Buter, Coretta; Oude Velthuis, Bob; Pas, Suzan D; Ruijs, Wilhelmina LM; Schmidt-Chanasit, Jonas; Vreden, Stephen GS; van der Werf, Tjip S; Reusken, Chantal BEM; Bierman, Wouter FW

    2017-01-01

    A Dutch traveller returning from Suriname in early March 2017, presented with fever and severe acute liver injury. Yellow fever was diagnosed by (q)RT-PCR and sequencing. During hospital stay, the patient’s condition deteriorated and she developed hepatic encephalopathy requiring transfer to the intensive care. Although yellow fever has not been reported in the last four decades in Suriname, vaccination is recommended by the World Health Organization for visitors to this country. PMID:28333617

  5. Yellow fever in two unvaccinated French tourists to Brazil, January and March, 2018.

    PubMed

    Oliosi, Emma; Serero Corcos, Chantal; Barroso, Paulo Feijo; Bleibtreu, Alexandre; Grard, Gilda; De Filippis, Bispo Ana Maria; Caumes, Eric

    2018-05-01

    We report two yellow fever cases in unvaccinated French travellers in Brazil in January and March 2018, respectively; one exposed during an excursion in Minas Gerais and the other in Ilha Grande. Both presented with fever, hepatitis, thrombocytopenia and leucopenia. Yellow fever diagnosis was based on RT-PCR and serological tests. Both patients recovered within a few days. The increasing occurrence of cases in unvaccinated travellers highlights the need to reinforce vaccination recommendation for travellers at-risk.

  6. T Cell-Mediated Immunity towards Yellow Fever Virus and Useful Animal Models.

    PubMed

    Watson, Alan M; Klimstra, William B

    2017-04-11

    The 17D line of yellow fever virus vaccines is among the most effective vaccines ever created. The humoral and cellular immunity elicited by 17D has been well characterized in humans. Neutralizing antibodies have long been known to provide protection against challenge with a wild-type virus. However, a well characterized T cell immune response that is robust, long-lived and polyfunctional is also elicited by 17D. It remains unclear whether this arm of immunity is protective following challenge with a wild-type virus. Here we introduce the 17D line of yellow fever virus vaccines, describe the current state of knowledge regarding the immunity directed towards the vaccines in humans and conclude with a discussion of animal models that are useful for evaluating T cell-mediated immune protection to yellow fever virus.

  7. Severe Dengue Fever Outbreak in Taiwan

    PubMed Central

    Wang, Sheng-Fan; Wang, Wen-Hung; Chang, Ko; Chen, Yen-Hsu; Tseng, Sung-Pin; Yen, Chia-Hung; Wu, Deng-Chyang; Chen, Yi-Ming Arthur

    2016-01-01

    Dengue fever (DF) is a vector-borne disease caused by dengue viruses (DENVs). Epidemic dengue occurs intermittently in Taiwan. In 2014, Taiwan experienced its largest DF outbreak. There were 15,732 DF cases reported. There were a total of 136 dengue hemorrhagic fever (DHF) cases, of which 20 resulted in death. Most DF cases were reported in southern Taiwan. A total of 15,043 (96%) cases were from Kaohsiung, a modern city in southern Taiwan. This report reviews DF epidemics in Taiwan during 2005–2014. The correlation between DF and DHF along with temperature and precipitation were conjointly examined. We conclude that most dengue epidemics in Taiwan resulted from imported DF cases. Results indicate three main factors that may have been associated with this DF outbreak in Kaohsiung: an underground pipeline explosion combined with subsequent rainfall and higher temperature. These factors may have enhanced mosquito breeding activity, facilitating DENV transmission. PMID:26572871

  8. Severe Dengue Fever Outbreak in Taiwan.

    PubMed

    Wang, Sheng-Fan; Wang, Wen-Hung; Chang, Ko; Chen, Yen-Hsu; Tseng, Sung-Pin; Yen, Chia-Hung; Wu, Deng-Chyang; Chen, Yi-Ming Arthur

    2016-01-01

    Dengue fever (DF) is a vector-borne disease caused by dengue viruses (DENVs). Epidemic dengue occurs intermittently in Taiwan. In 2014, Taiwan experienced its largest DF outbreak. There were 15,732 DF cases reported. There were a total of 136 dengue hemorrhagic fever (DHF) cases, of which 20 resulted in death. Most DF cases were reported in southern Taiwan. A total of 15,043 (96%) cases were from Kaohsiung, a modern city in southern Taiwan. This report reviews DF epidemics in Taiwan during 2005-2014. The correlation between DF and DHF along with temperature and precipitation were conjointly examined. We conclude that most dengue epidemics in Taiwan resulted from imported DF cases. Results indicate three main factors that may have been associated with this DF outbreak in Kaohsiung: an underground pipeline explosion combined with subsequent rainfall and higher temperature. These factors may have enhanced mosquito breeding activity, facilitating DENV transmission. © The American Society of Tropical Medicine and Hygiene.

  9. Geographical distribution of the red howler monkey (Alouatta seniculus) and yellow fever in Colombia.

    PubMed

    Piedrahita-Cortés, Juan; Soler-Tovar, Diego

    2016-02-11

    Colombia is a country with an important diversity of non-human primates, of which the red howler monkey (Alouatta seniculus) stands out because of its distribution and the role it plays in the occurrence of yellow fever.  To describe the geographic co-occurrence of Alouatta seniculus and the reported presence of yellow fever.  We conducted a descriptive study. The reported presence of yellow fever in Colombia was obtained from the reports and bulletins issued by the Instituto Nacional de Salud, and the study by Segura, et al. (2013). The occurrence of A. seniculus was determined based on the data from the Global Biodiversity Information Facility and the Colombian Biodiversity Information System. A map of the occurrence was developed using the DIVA-GIS program, and the ecological niche model under current conditions was created with the Maxent program.  The departments with the highest occurrence of A. seniculus were Antioquia, Meta and Casanare; 69.5% of the departments with reported history of yellow fever had co-occurrence with A. seniculus. The ecological niche model showed that Antioquia, Bolívar, La Guajira, Magdalena, Meta, Santander, Norte de Santander and Vichada had geographical portions with a probability rate nearing to 0.9 (90%).  In 69.5% of the departments with a history of yellow fever there was co-occurrence with A. seniculus, which is relevant because non-human primates play a well-known role as natural reservoirs of the virus, and they might contribute to the occurrence of the yellow fever, which makes them very useful as sentinels.

  10. [Culicidae insect fauna from rural zone in Amazonas State with incidence of sylvatic yellow fever].

    PubMed

    Fé, Nelson Ferreira; Barbosa Md, Maria das Graças Vale; Fé, Flávio Augusto Andrade; Guerra, Marcus Vinitius de Farias; Alecrim, Wilson Duarte

    2003-01-01

    After the occurrence of 14 sylvatic yellow fever cases in 10 cities in the State of Amazonas during 1996, an investigation into the presence of sylvatic yellow fever vectors was carried out. The material of larvae and adult insects was collected around residences and canopy trees within forests, using a light trap (CDC) and human bait. A total of 424 insects was collected. Thirty seven species were identified, some of which were sylvatic yellow fever vectors: Haemagogus janthinomys, Ha. leucocelaenus, Aedes fulvus.

  11. Yellow fever in a traveller returning from Suriname to the Netherlands, March 2017.

    PubMed

    Wouthuyzen-Bakker, Marjan; Knoester, Marjolein; van den Berg, Aad P; GeurtsvanKessel, Corine H; Koopmans, Marion Pg; Van Leer-Buter, Coretta; Oude Velthuis, Bob; Pas, Suzan D; Ruijs, Wilhelmina Lm; Schmidt-Chanasit, Jonas; Vreden, Stephen Gs; van der Werf, Tjip S; Reusken, Chantal Bem; Bierman, Wouter Fw

    2017-03-16

    A Dutch traveller returning from Suriname in early March 2017, presented with fever and severe acute liver injury. Yellow fever was diagnosed by (q)RT-PCR and sequencing. During hospital stay, the patient's condition deteriorated and she developed hepatic encephalopathy requiring transfer to the intensive care. Although yellow fever has not been reported in the last four decades in Suriname, vaccination is recommended by the World Health Organization for visitors to this country. This article is copyright of The Authors, 2017.

  12. [Scarlet fever outbreak in a public school in Granada in 2012].

    PubMed

    Fernández-Prada, M; Martínez-Diz, S; Colina López, A; Almagro Nievas, D; Martínez Romero, B; Huertas Martínez, J

    2014-04-01

    Scarlet fever is a streptococcal disease characterized by a skin rash in children. It can be endemic, epidemic or sporadic. In April 2012, the headmaster of a primary school in Granada reported an outbreak of scarlet fever in the school. To describe an outbreak of scarlet fever, analyse its epidemiological and clinical characteristics, and present the preventive measures taken to control it. A case-control study was conducted using an ad hoc questionnaire, developed for this purpose. The R program, Epidat 3.1 and Microsoft Excel were used for the statistics analysis. There were 13 cases and 30 controls. The attack rate was 3.9%. There was a statistically significant difference for the variable "relative affected". There has been a confirmed outbreak of person-to-person transmitted scarlet fever, and the main risk factor was having a relative with tonsillitis. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

  13. Advice on malaria and yellow fever prevention provided at travel agencies in Cuzco, Peru.

    PubMed

    Villanueva-Meyer, Pablo G; Garcia-Jasso, Carlos A; Springer, Chelsea A; Lane, Jenna K; Su, Bonny S; Hidalgo, Idania S; Goodrich, Mary R; Deichsel, Emily L; White, A C; Cabada, Miguel M

    2015-01-01

    Travelers receive medical advice from a variety of sources, including travel agencies. The aim of this study is to describe the quality of pre-travel advice provided by travel agencies in Cuzco to travelers interested in visiting malaria and yellow fever endemic areas. Trained medical students posed as tourists and visited travel agencies in Cuzco requesting travel advice for a trip to the southern Amazon of Peru, recording advice regarding risk and prevention of malaria and yellow fever. A total of 163 registered travel agencies were included in the study. The mean proposed tour duration was 6.8 days (±1.4 days) with a median time to departure of 3 days and a median tour cost of 805 US dollars (USD) [interquartile range (IQR) 580-1,095]. Overall, 45% employees failed to mention the risk for any illness. Eighteen percent of the employees acknowledged risk of malaria and 53% risk of yellow fever. However, 36% denied malaria risk and 2% denied risk of yellow fever in the region. The price of tours from travel agencies that did not mention any health risk was significantly lower [1,009.6 ± 500.5 vs 783.9 ± 402 USD, t (152) = 3, p < 0.01] compared with the price from agencies that did mention health risks. Almost all who acknowledged malaria (97%) and/or yellow fever (100%) were able to provide at least one recommendation for prevention. However, advice was not always accurate or spontaneously volunteered. Only 7% of the employees provided both correct scheduling and location information for administration of the yellow fever vaccine. The majority of registered travel agencies in Cuzco did not provide sufficient and accurate information regarding risk and prevention of malaria and yellow fever to travelers inquiring about trips to the southern Amazon of Peru. © 2014 International Society of Travel Medicine.

  14. Importation of yellow fever into China: assessing travel patterns.

    PubMed

    Wilder-Smith, Annelies; Leong, W Y

    2017-07-01

    Rapid increase in trade and a growing air passenger market encourages high travel volume between the regions associated with increasing risks of such importations including China. Eleven Chinese workers infected during the 2016 yellow fever (YF) outbreak in Angola imported YF into China highlighting the potential for spread into Asia. Using outbound and inbound travel data, we assessed travel patterns from and to YF endemic countries in relation to China. Among YF endemic countries, Angola has the second highest number of travellers into China and also receives the second highest number of Chinese visitors. We estimated that China needs around half a million YF vaccine doses to cover their population travelling to YF endemic countries. The recent importation cases into China also unmasked the low YF vaccination coverage among Chinese travellers and workers to Angola, indicating the need to ensure better adherence to the International Health Regulations. © International Society of Travel Medicine, 2017.. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  15. Yellow fever vaccination during treatment with infliximab in a patient with ulcerative colitis: A case report.

    PubMed

    Rüddel, J; Schleenvoigt, B T; Schüler, E; Schmidt, C; Pletz, M W; Stallmach, A

    2016-09-01

    We report the case of a 59-year-old patient who accidentally underwent live vaccination against yellow fever during continuous treatment with the TNF-α-antibody (AB) infliximab for ulcerative colitis. The clinical course showed fever of short duration and elevation of liver enzymes without further clinical complications. Yellow fever viremia was not detectable and protective antibodies were developed. A primary vaccination against yellow fever under infliximab has not been reported in the literature before, although vaccination is an important topic in IBD. Live vaccinations, like Stamaril(®) against yellow fever, are contraindicated during TNF-α-AB treatment. Treatment regimens containing TNF-α-AB are of growing importance, not only in gastroenterology, but also in rheumatology and dermatology. We discuss this topic by presenting our case and reviewing the current literature. © Georg Thieme Verlag KG Stuttgart · New York.

  16. T Cell-Mediated Immunity towards Yellow Fever Virus and Useful Animal Models

    PubMed Central

    Watson, Alan M.; Klimstra, William B.

    2017-01-01

    The 17D line of yellow fever virus vaccines is among the most effective vaccines ever created. The humoral and cellular immunity elicited by 17D has been well characterized in humans. Neutralizing antibodies have long been known to provide protection against challenge with a wild-type virus. However, a well characterized T cell immune response that is robust, long-lived and polyfunctional is also elicited by 17D. It remains unclear whether this arm of immunity is protective following challenge with a wild-type virus. Here we introduce the 17D line of yellow fever virus vaccines, describe the current state of knowledge regarding the immunity directed towards the vaccines in humans and conclude with a discussion of animal models that are useful for evaluating T cell-mediated immune protection to yellow fever virus. PMID:28398253

  17. An inactivated yellow fever 17DD vaccine cultivated in Vero cell cultures.

    PubMed

    Pereira, Renata C; Silva, Andrea N M R; Souza, Marta Cristina O; Silva, Marlon V; Neves, Patrícia P C C; Silva, Andrea A M V; Matos, Denise D C S; Herrera, Miguel A O; Yamamura, Anna M Y; Freire, Marcos S; Gaspar, Luciane P; Caride, Elena

    2015-08-20

    Yellow fever is an acute infectious disease caused by prototype virus of the genus Flavivirus. It is endemic in Africa and South America where it represents a serious public health problem causing epidemics of hemorrhagic fever with mortality rates ranging from 20% to 50%. There is no available antiviral therapy and vaccination is the primary method of disease control. Although the attenuated vaccines for yellow fever show safety and efficacy it became necessary to develop a new yellow fever vaccine due to the occurrence of rare serious adverse events, which include visceral and neurotropic diseases. The new inactivated vaccine should be safer and effective as the existing attenuated one. In the present study, the immunogenicity of an inactivated 17DD vaccine in C57BL/6 mice was evaluated. The yellow fever virus was produced by cultivation of Vero cells in bioreactors, inactivated with β-propiolactone, and adsorbed to aluminum hydroxide (alum). Mice were inoculated with inactivated 17DD vaccine containing alum adjuvant and followed by intracerebral challenge with 17DD virus. The results showed that animals receiving 3 doses of the inactivated vaccine (2 μg/dose) with alum adjuvant had neutralizing antibody titers above the cut-off of PRNT50 (Plaque Reduction Neutralization Test). In addition, animals immunized with inactivated vaccine showed survival rate of 100% after the challenge as well as animals immunized with commercial attenuated 17DD vaccine. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Population Screening for Chronic Q-Fever Seven Years after a Major Outbreak

    PubMed Central

    Morroy, Gabriëlla; van der Hoek, Wim; Albers, Jelle; Coutinho, Roel A.; Bleeker-Rovers, Chantal P.; Schneeberger, Peter M.

    2015-01-01

    Introduction From 2007 through 2010, the Netherlands experienced a large Q-fever epidemic, with 4,107 notifications. The most serious complication of Q-fever is chronic Q-fever. Method In 2014, we contacted all 2,161 adult inhabitants of the first village in the Netherlands affected by the Q-fever epidemic and offered to test for antibodies against Coxiella burnetii using immunofluorescence assay (IFA) to screen for chronic infections and assess whether large-scale population screening elsewhere is warranted. Results Of the 1,517 participants, 33.8% were IFA-positive. Six IFA-positive participants had an IgG phase I titer ≥1:512. Two of these six participants were previously diagnosed with chronic Q-fever. Chronic infection was diagnosed in one of the other four participants after clinical examination. Conclusions Seven years after the initial outbreak, seroprevalence remains high, but the yield of screening the general population for chronic Q-fever is low. A policy of screening known high-risk groups for chronic Q-fever in outbreak areas directly following an outbreak might be more efficient than population screening. A cost-effectiveness analysis should also be performed before initiating a population screening program for chronic Q-fever. PMID:26132155

  19. Interim Canadian recommendations for the use of a fractional dose of yellow fever vaccine during a vaccine shortage

    PubMed Central

    2016-01-01

    Summary This statement outlines interim recommendations intended for use during yellow fever vaccine shortages only. The recommendations differ from the standard recommendations for yellow fever vaccination in the Canadian Immunization Guide and in the Committee to Advise on Tropical Medicine and Travel (CATMAT) Statement for Travellers and Yellow Fever. PMID:29770023

  20. Experimental therapies for yellow fever

    PubMed Central

    Julander, Justin G.

    2013-01-01

    A number of viruses in the family Flaviviridae are the focus of efforts to develop effective antiviral therapies. Success has been achieved with inhibitors for the treatment of hepatitis C, and there is interest in clinical trials of drugs against dengue fever. Antiviral therapies have also been evaluated in patients with Japanese encephalitis and West Nile encephalitis. However, no treatment has been developed against the prototype flavivirus, yellow fever virus (YFV). Despite the availability of the live, attenuated 17D vaccine, thousands of cases of YF continue to occur each year in Africa and South America, with a significant mortality rate. In addition, a small number of vaccinees develop severe systemic infections with the 17D virus. This paper reviews current efforts to develop antiviral therapies, either directly targeting the virus or blocking detrimental host responses to infection. PMID:23237991

  1. Yellow fever in Brazil: thoughts and hypotheses on the emergence in previously free areas.

    PubMed

    Vasconcelos, Pedro Fernando da Costa

    2010-12-01

    This article describes and discusses factors associated to the reemergence of yellow fever and its transmission dynamics in the states of São Paulo (Southeastern Brazil) and Rio Grande do Sul (Southern) during 2008 and 2009. The following factors have played a pivotal role for the reemergence of yellow fever in these areas: large susceptible human population; high prevalence of vectors and primary hosts (non-human primates); favorable climate conditions, especially increased rainfall; emergence of a new genetic lineage; and circulation of people and/or monkeys infected by virus. There is a need for an effective surveillance program to prevent the reemergence of yellow fever in other Brazilian states.

  2. Administration of time-expired yellow fever vaccine: public health response and results of a serological investigation.

    PubMed

    Allen, K W; Nguyen-Van-Tam, J S; Howells, J

    1999-06-01

    The discovery that a local travel clinic had administered 101 doses of time-expired yellow fever vaccine over a six month period prompted an immediate investigation in order to advise vaccinees about to travel to areas where yellow fever is endemic. No data were available to provide adequate reassurance about the potential efficacy of time-expired vaccine, so a rapid serological investigation was conducted, which provided evidence that the yellow fever vaccine had remained potent beyond its expiry date.

  3. Predicting Dengue Fever Outbreaks in French Guiana Using Climate Indicators.

    PubMed

    Adde, Antoine; Roucou, Pascal; Mangeas, Morgan; Ardillon, Vanessa; Desenclos, Jean-Claude; Rousset, Dominique; Girod, Romain; Briolant, Sébastien; Quenel, Philippe; Flamand, Claude

    2016-04-01

    Dengue fever epidemic dynamics are driven by complex interactions between hosts, vectors and viruses. Associations between climate and dengue have been studied around the world, but the results have shown that the impact of the climate can vary widely from one study site to another. In French Guiana, climate-based models are not available to assist in developing an early warning system. This study aims to evaluate the potential of using oceanic and atmospheric conditions to help predict dengue fever outbreaks in French Guiana. Lagged correlations and composite analyses were performed to identify the climatic conditions that characterized a typical epidemic year and to define the best indices for predicting dengue fever outbreaks during the period 1991-2013. A logistic regression was then performed to build a forecast model. We demonstrate that a model based on summer Equatorial Pacific Ocean sea surface temperatures and Azores High sea-level pressure had predictive value and was able to predict 80% of the outbreaks while incorrectly predicting only 15% of the non-epidemic years. Predictions for 2014-2015 were consistent with the observed non-epidemic conditions, and an outbreak in early 2016 was predicted. These findings indicate that outbreak resurgence can be modeled using a simple combination of climate indicators. This might be useful for anticipating public health actions to mitigate the effects of major outbreaks, particularly in areas where resources are limited and medical infrastructures are generally insufficient.

  4. Immunity and immune response, pathology and pathologic changes: progress and challenges in the immunopathology of yellow fever.

    PubMed

    Quaresma, Juarez A S; Pagliari, Carla; Medeiros, Daniele B A; Duarte, Maria I S; Vasconcelos, Pedro F C

    2013-09-01

    Yellow fever is a viral hemorrhagic fever, which affects people living in Africa and South America and is caused by the yellow fever virus, the prototype species in the Flavivirus genus (Flaviviridae family). Yellow fever virus infection can produce a wide spectrum of symptoms, ranging from asymptomatic infection or oligosymptomatic illness to severe disease with a high fatality rate. In this review, we focus in the mechanisms associated with the physiopathology of yellow fever in humans and animal models. It has been demonstrated that several factors play a role in the pathological outcome of the severe form of the disease including direct viral cytopathic effect, necrosis and apoptosis of hepatocyte cells in the midzone, and a minimal inflammatory response as well as low-flow hypoxia and cytokine overproduction. New information has filled several gaps in the understanding of yellow fever pathogenesis and helped comprehend the course of illness. Finally, we discuss prospects for an immune therapy in the light of new immunologic, viral, and pathologic tools. Copyright © 2013 John Wiley & Sons, Ltd.

  5. Construction of yellow fever-influenza A chimeric virus particles.

    PubMed

    Oliveira, B C E P D; Liberto, M I M; Barth, O M; Cabral, M C

    2002-12-01

    In order to obtain a better understanding of the functional mechanisms involved in the fusogenesis of enveloped viruses, the influenza A (X31) and the yellow fever (17DD) virus particles were used to construct a chimeric structure based on their distinct pH requirements for fusion, and the distinct malleability of their nucleocapsids. The malleable nucleocapsid of the influenza A virus particle is characterized by a pleomorphic configuration when observed by electron microscopy. A heat inactivated preparation of X31 virus was used as a lectin to interact with the sialic acid domains present in the 17DD virus envelope. The E spikes of 17DD virus were induced to promote fusion of both envelopes, creating a double genome enveloped structure, the chimeric yellow fever-influenza A virus particle. These chimeric viral particles, originally denominated 'partículas virais quiméricas' (PVQ), were characterized by their infectious capacity for different biological systems. Cell inoculation with PVQ resulted in viral products that showed similar characteristics to those obtained after 17DD virus infections. Our findings open new opportunities towards the understanding of both virus particles and aspects of cellular physiologic quality control. The yellow fever-influenza A chimeric particles, by means of their hybrid composition, should be a valuable tool in the study of cell biology and the function of viral components. Copyright 2002 Elsevier Science B.V.

  6. CHRONOVAC VOYAGEUR: A study of the immune response to yellow fever vaccine among infants previously immunized against measles.

    PubMed

    Goujon, Catherine; Gougeon, Marie-Lise; Tondeur, Laura; Poirier, Béatrice; Seffer, Valérie; Desprès, Philippe; Consigny, Paul-Henri; Vray, Muriel

    2017-10-27

    For administration of multiple live attenuated vaccines, the Advisory Committee on Immunization Practices recommends either simultaneous immunization or period of at least 28days between vaccines, due to a possible reduction in the immune response to either vaccine. The main objective of this study was to compare the immune response to measles (alone or combined with mumps and rubella) and yellow fever vaccines among infants aged 6-24months living in a yellow fever non-endemic country who had receivedmeasles and yellow fever vaccines before travelling to a yellow fever endemic area. A retrospective, multicenter case-control study was carried out in 7 travel clinics in the Paris area from February 1st 2011 to march 31, 2015. Cases were defined as infants immunized with the yellow fever vaccine and with the measles vaccine, either alone or in combination with mumps and rubella vaccine, with a period of 1-27days between each immunization. For each case, two controls were matched based on sex and age: a first control group (control 1) was defined as infants having received the measles vaccine and the yellow fever vaccine simultaneously; a second control group (control 2) was defined as infants who had a period of more than 27days between receiving the measles vaccine and yellow fever vaccine. The primary endpoint of the study was the percentage of infants with protective immunity against yellow fever, measured by the titer of neutralizing antibodies in a venous blood sample. One hundred and thirty-one infants were included in the study (62 cases, 50 infants in control 1 and 19 infants in control 2). Of these, 127 (96%) were shown to have a protective titer of yellow fever antibodies. All 4 infants without a protective titer of yellow fever antibodies were part of control group 1. The measles vaccine, alone or combined with mumps and rubella vaccines, appears to have no influence on humoral immune response to the yellow fever vaccine when administered between 1 and 27

  7. NON-FATAL INFECTION OF MICE FOLLOWING INTRACEREBRAL INOCULATION OF YELLOW FEVER VIRUS

    PubMed Central

    Fox, John P.

    1943-01-01

    Observations have been reported which indicate that mice inoculated intracerebrally with active yellow fever virus may develop an infection which is not only non-fatal but may also be completely inapparent. The most extensive observations were made on mice which showed signs of infection but were still alive 22 days after inoculation with virus of one or another of several 17D substrains. In such cases, the infection usually progressed no further and partial or complete recovery often ensued. Agents other than yellow fever virus were excluded as a significant cause of such nonfatal infections by the failure of repeated attempts to isolate other infective agents, by the demonstration of antibodies against yellow fever virus in the sera of the mice, and by the demonstration of a high degree of resistance on the part of such surviving mice to reinoculation with large doses of neurotropic yellow fever virus. Completely inapparent infections with 17D virus were also shown to occur. Studies of apparently normal survivors of 17D virus titrations revealed a small but significant number of animals resistant to intracerebral challenge with neurotropic yellow fever virus. Further, pooled sera from such mice were shown to contain specific protective antibodies. The occurrence of non-fatal infections with 17D virus was found related to virus dose and substrain. Small doses of virus provoked a significantly higher proportion of non-fatal infections than large doses; while different 17D substrains, tested over equivalent ranges of virus dose, varied greatly with respect to the proportion of infections which did not terminate with death. In the case of two substrains (17DD low and 17D3), non-fatal infections (as demonstrated by resistance to intracerebral challenge with neurotropic virus) were sufficiently frequent to cause an increase, when included in the computation of the infective titers, of 25 per cent above the figures based on deaths alone. The demonstration of non

  8. Japanese encephalitis virus/yellow fever virus chimera is safe and confers full protection against yellow fever virus in intracerebrally challenged mice.

    PubMed

    Yang, Huiqiang; Yang, Huan; Li, Zhushi; Liu, Lina; Wang, Wei; He, Ting; Fan, Fengming; Sun, Yan; Liu, Jie; Li, Yuhua; Zeng, Xianwu

    2018-04-25

    Yellow fever (YF) is an acute viral haemorrhagic disease caused by the yellow fever virus (YFV), which remains a potential threat to public health. The live-attenuated YF vaccine (17D strain) is a safe and highly effective measure against YF. However, increasing adverse events have been associated with YF vaccinations in recent years; thus, safer, alternative vaccines are needed. In this study, using the Japanese encephalitis live vaccine strain SA14-14-2 as a backbone, a novel chimeric virus was constructed by replacing the pre-membrane (prM) and envelope (E) genes with their YFV 17D counterparts.The chimeric virus exhibited a reduced growth rate and a much smaller plaque morphology than did either parental virus. Furthermore, the chimera was much less neurovirulent than was YF17D and protected mice that were challenged with a lethal dose of the YF virus. These results suggest that this chimera has potential as a novel attenuated YF vaccine. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. A Possible connection between the 1878 yellow fever epidemic in the southern United States and the 1877-78 El Niño episode

    USGS Publications Warehouse

    Diaz, Henry F.; McCabe, Gregory J.

    1999-01-01

    This study documents some of the extreme climate anomalies that were recorded in 1877 and 1878 in parts of the eastern United States, with particular emphasis on highlighting the evolution of these anomalies, as they might have contributed to the epidemic. Other years with major outbreaks of yellow fever in the eighteenth and nineteenth centuries also occurred during the course of El Niño episodes, a fact that appears not to have been noted before in the literature.

  10. Yellow Fever Vaccination of a Primary Vaccinee During Adalimumab Therapy.

    PubMed

    Nash, Esther R; Brand, Myron; Chalkias, Spyridon

    2015-01-01

    In this case report, we describe a 63-year-old female with Crohn's disease since age 16 years, and on adalimumab therapy, who inadvertently received a yellow fever vaccine (YFV) 4 days before her next dose of adalimumab. She had never received YFV. Her next dose of tumor necrosis factor (TNF) antagonist was held. She did not report any adverse effects referable to the vaccine. Reverse transcriptase-polymerase chain reaction (RT-PCR) for yellow fever (YF) viral RNA on days 12 and 18 postvaccination was negative. Neutralizing antibody to YF virus vaccine was immunoprotective on day 18 following vaccination, which further increased by day 26. A neutralizing antibody obtained 2 years following vaccination also remained immunoprotective. © 2015 International Society of Travel Medicine.

  11. Crotoxin and phospholipases A₂ from Crotalus durissus terrificus showed antiviral activity against dengue and yellow fever viruses.

    PubMed

    Muller, Vanessa Danielle Menjon; Russo, Raquel Rinaldi; Cintra, Adelia Cristina Oliveira; Sartim, Marco Aurélio; Alves-Paiva, Raquel De Melo; Figueiredo, Luiz Tadeu Moraes; Sampaio, Suely Vilela; Aquino, Victor Hugo

    2012-03-15

    Dengue is the most important arbovirus in the world with an estimated of 50 million dengue infections occurring annually and approximately 2.5 billion people living in dengue endemic countries. Yellow fever is a viral hemorrhagic fever with high mortality that is transmitted by mosquitoes. Effective vaccines against yellow fever have been available for almost 70 years and are responsible for a significant reduction of occurrences of the disease worldwide; however, approximately 200,000 cases of yellow fever still occur annually, principally in Africa. Therefore, it is a public health priority to develop antiviral agents for treatment of these virus infections. Crotalus durissus terrificus snake, a South American rattlesnake, presents venom with several biologically actives molecules. In this study, we evaluated the antiviral activity of crude venom and isolated toxins from Crotalus durissus terrificus and found that phospholipases A₂ showed a high inhibition of Yellow fever and dengue viruses in VERO E6 cells. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Serological reactions in Rhesus monkeys inoculated with the 17D strain of yellow fever virus.

    PubMed

    GROOT, H

    1962-01-01

    Haemagglutination-inhibition tests, which depend on the appearance of haemagglutination-inhibiting antibodies in the serum in virus infections, are in common use in the study of arthropod-borne diseases. This paper contains the results of an investigation into the appearance and pattern of haemagglutination-inhibiting antibodies in the serum of rhesus monkeys inoculated intracerebrally with the 17D strain of yellow fever virus during the testing of seed lots of yellow fever vaccine. These antibodies appeared on the tenth day after inoculation, and were still demonstrable four years later. In all of the eight monkeys tested complement-fixing and neutralizing antibodies against yellow fever antigens also developed, and in six out of the eight heterologous antigens developed.

  13. Yellow fever 17-D vaccine is neurotropic and produces encephalitis in immunosuppressed hamsters.

    PubMed

    Mateo, Rosa I; Xiao, Shu-Yuan; Travassos da Rosa, Amelia P A; Lei, Hao; Guzman, Hilda; Lu, Liang; Tesh, Robert B

    2007-11-01

    Immunosuppressed (cyclophosphamide) adult golden hamsters inoculated intraperitoneally (i.p.) with wild-type Asibi yellow fever virus (YFV) developed a rapidly fatal illness. Histopathologic and immunohistochemical studies of tissues from these animals showed typical hepatic changes of severe yellow fever (inflammation, hepatocyte necrosis, and steatosis) without brain involvement. In contrast, 50% of immunosuppressed hamsters receiving the YFV-17D-attenuated vaccine developed a slowly progressive encephalitic-type illness. Brain tissue from these latter animals revealed focal neuronal changes, inflammation, and YFV antigen-positive neurons; however, the liver and spleen appeared normal. YFV was isolated from brain cultures of many of these animals. Immunocompetent (non-immunosuppressed) hamsters inoculated with both viruses developed a subclinical infection. Results of this study indicate that wild-type YFV is hepatotropic in immunosuppressed hamsters, whereas the attenuated YFV-17 is primarily neurotropic. These findings support current recommendations against yellow fever vaccination of immunosuppressed/immunocompromised people and suggest that this hamster model might be useful for monitoring the safety of other live-attenuated YFV vaccines.

  14. Investigations into yellow fever virus and other arboviruses in the northern regions of Kenya.

    PubMed

    Henderson, B E; Metselaar, D; Kirya, G B; Timms, G L

    1970-01-01

    Previous studies having shown an appreciable level of yellow fever immunity to exist in northern Kenya, further epidemiological and serological surveys were carried out there in 1968 in an attempt to define more clearly the distribution of yellow fever and to locate possible vector and reservoir hosts of the disease; these surveys also provided information on a number of other arboviruses.Altogether 436 sera from 5 areas in northern Kenya were screened by haemagglutination-inhibition tests with 8 antigens, and 107 of these sera by neutralization tests for Group-B arboviruses. Small numbers of yellow-fever-immune adults were found in Ileret, Garissa, Loglogo and Mikona. At Marsabit high proportions of immune adults and children were found among the Burgi tribe. As the Burgi are permanent agricultural workers on Marsabit Mountain, an entomological investigation was made, over 15 000 mosquitos being collected. From these, 13 strains of Pongola virus, 1 strain of Semliki Forest virus and an unidentified virus were isolated, but no yellow fever strains. Aedes africanus and Aedes simpsoni were not found at Marsabit; small numbers of Aedes aegypti were collected biting man. The vector potential of other mosquitos collected (particularly Mansonia africana, which is present throughout the year) is discussed.

  15. Molecular Characterization of Group A Streptococcus Strains Isolated during a Scarlet Fever Outbreak

    PubMed Central

    Perea-Mejía, Luis M.; Inzunza-Montiel, Alma E.; Cravioto, Alejandro

    2002-01-01

    Forty group A streptococcus (GAS) isolates, recovered during a scarlet fever outbreak, were grouped based on their DdeI restriction profiles from emm amplicons. Twenty-seven isolates were identified by sequencing as emm2. The emm2 isolates showed the speA1, speB1, and speC1 alleles. Isolation of this GAS type from scarlet fever outbreaks is uncommon. PMID:11773132

  16. STUDIES ON YELLOW FEVER IN SOUTH AMERICA

    PubMed Central

    Davis, Nelson C.; Shannon, Raymond C.

    1929-01-01

    1. Batches of Aëdes (Stegomyia) aegypti which had fed on monkeys in the early febrile stage of yellow fever and which has subsequently passed the usually accepted extrinsic incubation period for the virus, failed to transmit the disease to normal monkeys in approximately fifty per cent of the experiments. During the same time over eighty per cent of blood transfers were successful. 2. The monkeys which failed to show fever following mosquito bites later proved resistant to the inoculation of blood or tissues containing virus. 3. The incubation, or afebrile, period in monkeys following the bites of infected mosquitoes varied from less than twenty-four hours to fifteen days. It averaged somewhat longer in non-fatal than in fatal infections. PMID:19869665

  17. Isolation of yellow fever virus from mosquitoes in Misiones province, Argentina.

    PubMed

    Goenaga, Silvina; Fabbri, Cintia; Dueñas, Juan Climaco Rondan; Gardenal, Cristina Noemí; Rossi, Gustavo Carlos; Calderon, Gladys; Morales, Maria Alejandra; Garcia, Jorge Braulio; Enria, Delia Alcira; Levis, Silvana

    2012-11-01

    Yellow fever (YF) is a viral hemorrhagic fever endemic to tropical regions of South America and Africa. From 2007 to 2009 an important epidemic/epizootic of YF was detected in different populations of howler monkeys (Alouatta species) in Misiones, a northeastern Argentinian province. Yellow fever virus (YFV) infection was researched and documented by laboratory tests in humans and in dead Alouatta carayá. The objective of that research was to investigate the circulation of YFV in mosquitoes, which could be implicated in the sylvatic transmission of YF in Argentina. The above-mentioned mosquitoes were captured in the same geographical region where the epizootic took place. A YFV strain was isolated in cell culture from pools of Sabethes albiprivus. This study is not only the first isolation of YFV from mosquitoes in Argentina, but it is also the first YFV isolation reported in the species Sabethes albiprivus, suggesting that this species might be playing a key role in sylvatic YF in Argentina.

  18. Investigation of a Q fever outbreak in a Scottish co-located slaughterhouse and cutting plant.

    PubMed

    Wilson, L E; Couper, S; Prempeh, H; Young, D; Pollock, K G J; Stewart, W C; Browning, L M; Donaghy, M

    2010-12-01

    Outbreaks of Q fever are rare in the UK. In 2006, the largest outbreak of Q fever in Scotland occurred at a co-located slaughterhouse and cutting plant with 110 cases. Preliminary investigations pointed to the sheep lairage being the potential source of exposure to the infective agent. A retrospective cohort study was carried out among workers along with environmental sampling to guide public health interventions. A total of 179 individuals were interviewed of whom 66 (37%) were migrant workers. Seventy-five (41.9%) were serologically confirmed cases. Passing through a walkway situated next to the sheep lairage, a nearby stores area, and being male were independently associated with being serologically positive for Q fever. The large proportion of migrant workers infected presented a significant logistical problem during outbreak investigation and follow up. The topic of vaccination against Q fever for slaughterhouse workers is contentious out with Australasia, but this outbreak highlights important occupational health issues. © 2009 Blackwell Verlag GmbH.

  19. Reemergence of yellow fever in Ethiopia after 50 years, 2013: epidemiological and entomological investigations.

    PubMed

    Lilay, Abrham; Asamene, Negga; Bekele, Abyot; Mengesha, Mesfin; Wendabeku, Milliyon; Tareke, Israel; Girmay, Abiy; Wuletaw, Yonas; Adossa, Abate; Ba, Yamar; Sall, Amadou; Jima, Daddi; Mengesha, Debritu

    2017-05-15

    Yellow Fever (YF) is a viral hemorrhagic disease transmitted by aedes mosquito species. Approximately, 200,000 cases and 30,000 deaths occur worldwide every year. In Ethiopia, the last outbreak was reported in 1966 with 2200 cases and 450 deaths. A number of cases with deaths from unknown febrile illness reported from South Ari district starting from November 2012. This investigation was conducted to identify the causative agent, source of the outbreak and recommend appropriate interventions. Medical records were reviewed and Patients and clinicians involved in managing the case were interviewed. Descriptive data analysis was done by time, person and place. Serum samples were collected for serological analysis it was done using Enzyme-linked Immunosorbent Assay for initial screening and confirmatory tests were done using Plaque Reduction and Neutralization Test. Breteau and container indices were used for the entomological investigation to determine the risk of epidemic. A total of 141 Suspected YF cases with 43 deaths (CFR = 30.5%) were reported from November 2012 to October 2013 from South Omo Zone. All age groups were affected (mean 27.5, Range 1-75 Years). Of the total cases, 85.1% cases had jaundice and 56.7% cases had fever. Seven of the 21 samples were IgM positive for YF virus. Aedes bromeliae and Aedes aegypti were identified as responsible vectors of YF in affected area. The Breteau indices of Arkisha and Aykamer Kebeles were 44.4% and 33.3%, whereas the container indices were 12.9% and 22.2%, respectively. The investigation revealed that YF outbreak was reemerged after 50 years in Ethiopia. Vaccination should be given for the affected and neighboring districts and Case based surveillance should be initiated to detect every case.

  20. A Meta-Analysis of Serological Response Associated with Yellow Fever Vaccination.

    PubMed

    Jean, Kévin; Donnelly, Christl A; Ferguson, Neil M; Garske, Tini

    2016-12-07

    Despite previous evidence of high level of efficacy, no synthetic metric of yellow fever (YF) vaccine efficacy is currently available. Based on the studies identified in a recent systematic review, we conducted a random-effects meta-analysis of the serological response associated with YF vaccination. Eleven studies conducted between 1965 and 2011 representing 4,868 individual observations were included in the meta-analysis. The pooled estimate of serological response was 97.5% (95% confidence interval [CI] = 82.9-99.7%). There was evidence of between-study heterogeneity (I 2 = 89.1%), but this heterogeneity did not appear to be related to study size, study design, or seroconversion measurement or definition. Pooled estimates were significantly higher (P < 0.0001) among studies conducted in nonendemic settings (98.9%, 95% CI = 98.2-99.4%) than among those conducted in endemic settings (94.2%, 95% CI = 83.8-98.1%). These results provide background information against which to evaluate the efficacy of fractional doses of YF vaccine that may be used in outbreak situations. © The American Society of Tropical Medicine and Hygiene.

  1. Suspected YF-AND after yellow fever vaccination in Finland.

    PubMed

    Jääskeläinen, Anne J; Huhtamo, Eili; Kivioja, Reetta; Domingo, Cristina; Vene, Sirkka; Kallio-Kokko, Hannimari; Niedrig, Matthias; Tienari, Pentti J; Vapalahti, Olli

    2014-11-01

    Yellow fever (YF) vaccine is considered safe but vaccine-associated complications have also been encountered. We report neurological symptoms after YF-vaccination in a previously healthy Finnish male. Other concomitant infections or causes for the symptoms could not be identified. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Zika virus infection, associated microcephaly, and low yellow fever vaccination coverage in Brazil: is there any causal link?

    PubMed

    De Góes Cavalcanti, Luciano Pamplona; Tauil, Pedro Luiz; Alencar, Carlos Henrique; Oliveira, Wanderson; Teixeira, Mauro Martins; Heukelbach, Jorg

    2016-06-30

    Since the end of 2014, Zika virus (ZIKV) infection has been rapidly spreading in Brazil. To analyze the possible association of yellow fever vaccine with a protective effect against ZIKV-related microcephaly, the following spatial analyses were performed, using Brazilian municipalities as units: i) yellow fever vaccination coverage in Brazilian municipalities in individuals aged 15-49; ii) reported cases of microcephaly by municipality; and iii) confirmed cases of microcephaly related to ZIKV, by municipality. SaTScan software was used to identify clusters of municipalities for high risk of microcephaly. There were seven significant high risk clusters of confirmed microcephaly cases, with four of them located in the Northeast where yellow fever vaccination rates were the lowest. The clusters harbored only 2.9% of the total population of Brazil, but 15.2% of confirmed cases of microcephaly. We hypothesize that pregnant women in regions with high yellow fever vaccination coverage may pose their offspring to lower risk for development of microcephaly. There is an urgent need for systematic studies to confirm the possible link between low yellow fever vaccination coverage, Zika virus infection and microcephaly.

  3. Persistent seropositivity for yellow fever in a previously vaccinated autologous hematopoietic stem cell transplantation recipient.

    PubMed

    Hayakawa, Kayoko; Takasaki, Tomohiko; Tsunemine, Hiroko; Kanagawa, Shuzo; Kutsuna, Satoshi; Takeshita, Nozomi; Mawatari, Momoko; Fujiya, Yoshihiro; Yamamoto, Kei; Ohmagari, Norio; Kato, Yasuyuki

    2015-08-01

    The duration of a protective level of yellow fever antibodies after autologous hematopoietic stem cell transplantation in a previously vaccinated person is unclear. The case of a patient who had previously been vaccinated for yellow fever and who remained seropositive for 22 months after autologous peripheral blood stem cell transplantation for malignant lymphoma is described herein. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Yellow fever risk assessment in the Central African Republic

    PubMed Central

    Staples, J. Erin; Diallo, Mawlouth; Janusz, Kristen B.; Manengu, Casimir; Lewis, Rosamund F.; Perea, William; Yactayo, Sergio; Sall, Amadou A.

    2015-01-01

    Background Starting in 2008, the Central African Republic (CAR) experienced an unprecedented number of reported yellow fever (YF) cases. A risk assessment of YF virus (YFV) activity was conducted to estimate potential disease risk and vaccine needs. Methods A multistage cluster sampling design was used to sample humans, non-human primates, and mosquitoes in distinct ecologic zones. Humans and non-human primates were tested for YFV-specific antibodies; mosquitoes were tested for YFV RNA. Results Overall, 13.3% (125/938) of humans were found to have naturally-acquired YFV antibodies. Antibody levels were higher in zones in the southern and south central regions of CAR. All sampled non-human primates (n=56) were known YFV reservoirs; one tested positive for YFV antibodies. Several known YF vectors were identified including Aedes africanus, Ae. aegypti, Ae. luteocephalus, and Ae. simpsoni. Several more urban locations were found to have elevated Breateau and Container indices for Ae. aegypti. Conclusions A country-wide assessment of YF risk found YFV to be endemic in CAR. The potential for future YF cases and outbreaks, however, varied by ecologic zone. Improved vaccination coverage through mass campaign and childhood immunization was recommended to mitigate the YF risk. PMID:24947520

  5. A qualitatively validated mathematical-computational model of the immune response to the yellow fever vaccine.

    PubMed

    Bonin, Carla R B; Fernandes, Guilherme C; Dos Santos, Rodrigo W; Lobosco, Marcelo

    2018-05-25

    Although a safe and effective yellow fever vaccine was developed more than 80 years ago, several issues regarding its use remain unclear. For example, what is the minimum dose that can provide immunity against the disease? A useful tool that can help researchers answer this and other related questions is a computational simulator that implements a mathematical model describing the human immune response to vaccination against yellow fever. This work uses a system of ten ordinary differential equations to represent a few important populations in the response process generated by the body after vaccination. The main populations include viruses, APCs, CD8+ T cells, short-lived and long-lived plasma cells, B cells and antibodies. In order to qualitatively validate our model, four experiments were carried out, and their computational results were compared to experimental data obtained from the literature. The four experiments were: a) simulation of a scenario in which an individual was vaccinated against yellow fever for the first time; b) simulation of a booster dose ten years after the first dose; c) simulation of the immune response to the yellow fever vaccine in individuals with different levels of naïve CD8+ T cells; and d) simulation of the immune response to distinct doses of the yellow fever vaccine. This work shows that the simulator was able to qualitatively reproduce some of the experimental results reported in the literature, such as the amount of antibodies and viremia throughout time, as well as to reproduce other behaviors of the immune response reported in the literature, such as those that occur after a booster dose of the vaccine.

  6. Epidemic preparedness and management: A guide on Lassa fever outbreak preparedness plan.

    PubMed

    Fatiregun, Akinola Ayoola; Isere, Elvis Efe

    2017-01-01

    Epidemic prone diseases threaten public health security. These include diseases such as cholera, meningitis, and hemorrhagic fevers, especially Lassa fever for which Nigeria reports considerable morbidity and mortality annually. Interestingly, where emergency epidemic preparedness plans are in place, timely detection of outbreaks is followed by a prompt and appropriate response. Furthermore, due to the nature of spread of Lassa fever in an outbreak setting, there is the need for health-care workers to be familiar with the emerging epidemic management framework that has worked in other settings for effective preparedness and response. This paper, therefore, discussed the principles of epidemic management using an emergency operating center model, review the epidemiology of Lassa fever in Nigeria, and provide guidance on what is expected to be done in preparing for epidemic of the disease at the health facilities, local and state government levels in line with the Integrated Disease Surveillance and Response strategy.

  7. Yellow fever disease: density equalizing mapping and gender analysis of international research output.

    PubMed

    Bundschuh, Matthias; Groneberg, David A; Klingelhoefer, Doris; Gerber, Alexander

    2013-11-18

    A number of scientific papers on yellow fever have been published but no broad scientometric analysis on the published research of yellow fever has been reported.The aim of the article based study was to provide an in-depth evaluation of the yellow fever field using large-scale data analysis and employment of bibliometric indicators of production and quantity. Data were retrieved from the Web of Science database (WoS) and analyzed as part of the NewQis platform. Then data were extracted from each file, transferred to databases and visualized as diagrams. Partially by means of density-equalizing mapping makes the findings clear and emphasizes the output of the analysis. In the study period from 1900 to 2012 a total of 5,053 yellow fever-associated items were published by 79 countries. The United States (USA) having the highest publication rate at 42% (n = 751) followed by far from Brazil (n = 203), France (n = 149) and the United Kingdom (n = 113). The most productive journals are the "Public Health Reports", the "American Journal of Tropical Medicine and Hygiene" and the "Journal of Virology". The gender analysis showed an overall steady increase of female authorship from 1950 to 2011. Brazil is the only country of the five most productive countries with a higher proportion of female scientists. The present data shows an increase in research productivity over the entire study period, in particular an increase of female scientists. Brazil shows a majority of female authors, a fact that is confirmed by other studies.

  8. Neurological adverse events temporally associated to mass vaccination against yellow fever in Juiz de Fora, Brazil, 1999-2005.

    PubMed

    Fernandes, Guilherme Côrtes; Camacho, Luiz Antonio Bastos; Sá Carvalho, Marilia; Batista, Maristela; de Almeida, Sonia Maria Rodrigues

    2007-04-20

    The identification of adverse events following immunization (AEFI) and their prompt investigation are important to allow a timely and scientifically based response to the users of immunization services. This article presents an analysis of notified AEFI cases between 1999 and 2005 and their temporal association with 2001 yellow fever vaccination campaign, AEFI notification attributed to yellow fever vaccination rose from 0.06 to 1.32 per 100,000 vaccinees in Brazil, between 1998 and 2000. During the 2001 yellow fever mass vaccination campaign held in Juiz de Fora, Brazil, 12 cases of aseptic meningitis were temporally associated to yellow fever vaccination, but clinical and laboratory data were not available to confirm nor deny causality. Epidemiological studies associated to enhanced surveillance and standardized protocols should take advantage of public health interventions like mass vaccination campaigns and implementation of new vaccination strategies in order to assess and investigate vaccine safety.

  9. Insights into human CD8(+) T-cell memory using the yellow fever and smallpox vaccines.

    PubMed

    Ahmed, Rafi; Akondy, Rama S

    2011-03-01

    Live virus vaccines provide a unique opportunity to study human CD8(+) T-cell memory in the context of a controlled, primary acute viral infection. Yellow fever virus-17D and Dryvax are two such live-virus vaccines that are highly efficacious, used worldwide and provide long-term immunity against yellow fever and smallpox respectively. In this review, we describe the properties of virus-specific memory CD8(+) T cells generated in smallpox and yellow fever vaccinees. We address fundamental questions regarding magnitude, functional quality and longevity of the CD8(+) T-cell response, which are otherwise challenging to address in humans. These findings provide insights into the attributes of the human immune system as well as provide a benchmark for the optimal quality of a CD8(+) T-cell response that can be used to evaluate novel candidate vaccines.

  10. Modeling Classical Swine Fever Outbreak-Related Outcomes

    PubMed Central

    Yadav, Shankar; Olynk Widmar, Nicole J.; Weng, Hsin-Yi

    2016-01-01

    The study was carried out to estimate classical swine fever (CSF) outbreak-related outcomes, such as epidemic duration and number of infected, vaccinated, and depopulated premises, using defined most likely CSF outbreak scenarios. Risk metrics were established using empirical data to select the most likely CSF outbreak scenarios in Indiana. These scenarios were simulated using a stochastic between-premises disease spread model to estimate outbreak-related outcomes. A total of 19 single-site (i.e., with one index premises at the onset of an outbreak) and 15 multiple-site (i.e., with more than one index premises at the onset of an outbreak) outbreak scenarios of CSF were selected using the risk metrics. The number of index premises in the multiple-site outbreak scenarios ranged from 4 to 32. The multiple-site outbreak scenarios were further classified into clustered (N = 6) and non-clustered (N = 9) groups. The estimated median (5th, 95th percentiles) epidemic duration (days) was 224 (24, 343) in the single-site and was 190 (157, 251) and 210 (167, 302) in the clustered and non-clustered multiple-site outbreak scenarios, respectively. The median (5th, 95th percentiles) number of infected premises was 323 (0, 488) in the single-site outbreak scenarios and was 529 (395, 662) and 465 (295, 640) in the clustered and non-clustered multiple-site outbreak scenarios, respectively. Both the number and spatial distributions of the index premises affected the outcome estimates. The results also showed the importance of implementing vaccinations to accommodate depopulation in the CSF outbreak controls. The use of routinely collected surveillance data in the risk metrics and disease spread model allows end users to generate timely outbreak-related information based on the initial outbreak’s characteristics. Swine producers can use this information to make an informed decision on the management of swine operations and continuity of business, so that potential losses

  11. The seasonal influence of climate and environment on yellow fever transmission across Africa.

    PubMed

    Hamlet, Arran; Jean, Kévin; Perea, William; Yactayo, Sergio; Biey, Joseph; Van Kerkhove, Maria; Ferguson, Neil; Garske, Tini

    2018-03-01

    Yellow fever virus (YFV) is a vector-borne flavivirus endemic to Africa and Latin America. Ninety per cent of the global burden occurs in Africa where it is primarily transmitted by Aedes spp, with Aedes aegypti the main vector for urban yellow fever (YF). Mosquito life cycle and viral replication in the mosquito are heavily dependent on climate, particularly temperature and rainfall. We aimed to assess whether seasonal variations in climatic factors are associated with the seasonality of YF reports. We constructed a temperature suitability index for YFV transmission, capturing the temperature dependence of mosquito behaviour and viral replication within the mosquito. We then fitted a series of multilevel logistic regression models to a dataset of YF reports across Africa, considering location and seasonality of occurrence for seasonal models, against the temperature suitability index, rainfall and the Enhanced Vegetation Index (EVI) as covariates alongside further demographic indicators. Model fit was assessed by the Area Under the Curve (AUC), and models were ranked by Akaike's Information Criterion which was used to weight model outputs to create combined model predictions. The seasonal model accurately captured both the geographic and temporal heterogeneities in YF transmission (AUC = 0.81), and did not perform significantly worse than the annual model which only captured the geographic distribution. The interaction between temperature suitability and rainfall accounted for much of the occurrence of YF, which offers a statistical explanation for the spatio-temporal variability in transmission. The description of seasonality offers an explanation for heterogeneities in the West-East YF burden across Africa. Annual climatic variables may indicate a transmission suitability not always reflected in seasonal interactions. This finding, in conjunction with forecasted data, could highlight areas of increased transmission and provide insights into the occurrence of

  12. The 17D-204 and 17DD yellow fever vaccines: an overview of major similarities and subtle differences.

    PubMed

    Ferreira, Clarissa de Castro; Campi-Azevedo, Ana Carolina; Peruhype-Magalhāes, Vanessa; Costa-Pereira, Christiane; Albuquerque, Cleandro Pires de; Muniz, Luciana Feitosa; Yokoy de Souza, Talita; Oliveira, Ana Cristina Vanderley; Martins-Filho, Olindo Assis; da Mota, Licia Maria Henrique

    2018-01-01

    The yellow fever vaccine is a live attenuated virus vaccine that is considered one of the most efficient vaccines produced to date. The original 17D strain generated the substrains 17D-204 and 17DD, which are used for the current production of vaccines against yellow fever. The 17D-204 and 17DD substrains present subtle differences in their nucleotide compositions, which can potentially lead to variations in immunogenicity and reactogenicity. We will address the main changes in the immune responses induced by the 17D-204 and 17DD yellow fever vaccines and report similarities and differences between these vaccines in cellular and humoral immunity . This is a relevant issue in view of the re-emergence of yellow fever in Uganda in 2016 and in Brazil in the beginning of 2017. Areas covered: This article will be divided into 8 sections that will analyze the innate immune response, adaptive immune response, humoral response, production of cytokines, immunity in children, immunity in the elderly, gene expression and adverse reactions. Expert commentary: The 17D-204 and 17DD yellow fever vaccines present similar immunogenicity, with strong activation of the cellular and humoral immune responses. Additionally, both vaccines have similar adverse effects, which are mostly mild and thus are considered safe.

  13. Yellow fever vaccine-associated neurotropic disease (YEL-AND) - A case report.

    PubMed

    Florczak-Wyspiańska, Jolanta; Nawotczyńska, Ewa; Kozubski, Wojciech

    Yellow fever (YF) is a mosquito-borne viral hemorrhagic fever, which is a serious and potentially fatal disease with no specific antiviral treatment that can be effectively prevented by an attenuated vaccine (YEL). Despite the long history of safe and efficacious YF vaccination, sporadic case reports of serious adverse events (SAEs) have been reported, including yellow fever vaccine-associated neurotropic disease (YEL-AND). YEL-AND usually appears within one month of YF vaccination, manifesting as meningoencephalitis, Guillain-Barré syndrome (GBS) or acute disseminated encephalomyelitis (ADEM). We report a case of YEL-AND with meningitis presentation in a 39-year-old Caucasian man without evidence of significant risk factors, which was confirmed by the presence of the YF virus and specific immunoglobulin G (IgG) antibodies in the cerebrospinal fluid (CSF). In conclusion, we should stress the importance of balancing the risk of SAEs associated with the vaccine and the benefits of YF vaccination for each patient individually. Copyright © 2016 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  14. Gestational exposure to yellow fever vaccine at different developmental stages induces behavioral alterations in the progeny.

    PubMed

    Marianno, P; Salles, M J S; Sonego, A B; Costa, G A; Galvão, T C; Lima, G Z; Moreira, E G

    2013-01-01

    The most effective method to prevent yellow fever and control the disease is a vaccine made with attenuated live virus. Due to the neurological tropism of the virus, preventive vaccination is not recommended for infants under 6 months and for pregnant women. However there is a paucity of data regarding the safety for pregnant women and there are no experimental studies investigating adverse effects to the offspring after maternal exposure to the vaccine. This study aimed to investigate, in mice, the effects of maternal exposure to the yellow fever vaccine at three different gestational ages on the physical and behavioral development of the offspring. Pregnant Swiss mice received a single subcutaneous injection of water for injection (control groups) or 2 log Plaque Forming Units (vaccine-treated groups) of the yellow fever vaccine on gestational days (GD) 5, 10 or 15. Neither maternal signs of toxicity nor alterations in physical development and reflex ontogeny of the offspring were observed in any of the groups. Data from behavioral evaluation indicated that yellow fever vaccine exposure induced motor hypoactivity in 22-day-old females independent of the day of exposure; and in 60-day-old male and female pups exposed at GD 10. Moreover, 22-day-old females also presented with a deficit in habituation memory. Altogether, these results indicate that in utero exposure to the yellow fever vaccine may induce behavioral alterations in the pups that may persist to adulthood in the absence of observed maternal toxicity or disruption of physical development milestones or reflex ontogeny. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Proved and potential vectors of yellow fever in South Africa

    PubMed Central

    De Meillon, Botha

    1954-01-01

    This paper, based on records obtained from the Entomology Department of the South African Institute for Medical Research, Johannesburg, gives a summary of the distribution, adult habits, and breeding-places of the proved and potential vectors of yellow fever in South Africa. PMID:13209304

  16. Epidemiological features and control of an outbreak of scarlet fever in a Perth primary school.

    PubMed

    Feeney, Kynan T; Dowse, Gary K; Keil, Anthony D; Mackaay, Christine; McLellan, Duncan

    2005-01-01

    Scarlet fever was associated with feared outbreaks and mortality in the 19th Century. It occurs sporadically in modern society and infection is readily treated with antibiotics. We report on a scarlet fever outbreak in children attending a primary school in Perth, Western Australia, in late 2003. A total of 13 cases were identified over a five week period. Six of the cases were pre-primary children (ages 4 to 5) from the same class of 26 children (attack rate 23.1%). Three of the remaining seven cases were older siblings of pre-primary cases who developed scarlet fever after their younger siblings. Screening of the children and teachers from the two pre-primary classes at the school yielded 12 positive pharyngeal swabs for group A Streptococcus. Emm-typing of the screening isolates indicated that a common strain was circulating within the outbreak pre-primary class, with four of six isolates identified as emm-type 3. The overall group A Streptococcus carriage rate in screened students in this class was 31.6 per cent and the carriage rate for emm-type 3 was 21.1 per cent. Carriers were treated with oral penicillin V to eradicate carriage and control the outbreak. No further cases of scarlet fever were reported after the treatment of pharyngeal carriers. Outbreaks of scarlet fever still occur in young children and identification and treatment of carriers may still be valuable.

  17. [Serological diagnosis of dengue and yellow fever infections in suspected cases from Pará State, Brazil, 1999].

    PubMed

    de Araújo, Tais Pinheiro; Rodrigues, Sueli Guerreiro; Costa, Maria Irene Weyl de A; Vasconcelos, Pedro Fernando da Costa; da Rosa, Amélia P A Travassos

    2002-01-01

    From June to December 1999, 785 serum samples were obtained from patients clinically suspected of having dengue or yellow fever. The patients were referred by public health centers distributed within the six mesoregions of Par State, Brazil. Serum samples were tested for Flavivirus antibodies by hemagglutination inhibition test and for dengue and yellow fever viruses by enzyme-linked immunosorbent assay for IgM detection. Of the sera collected, 563 (71.7%) were positive by HI test and out of these 150 (26.6%) were positive by ELISA-IgM. Dengue virus was responsible for most of the recent infections in all regions; yellow fever cases detected in the current study were restricted to the Maraj and Southeast regions.

  18. Investigation of an outbreak of "humidifier fever" in a print shop.

    PubMed

    Mamolen, M; Lewis, D M; Blanchet, M A; Satink, F J; Vogt, R L

    1993-03-01

    An outbreak of "humidifier fever" affected 16 (57%) of 28 workers in a print shop. The most common symptoms were myalgia, chills or subjective fever, and cough. Illness began 5-13 hours after entering the workplace, and lasted 2-24 hours. A humidifier in use the day of the outbreak was found to be contaminated with fungi, amebae, and Gram-negative bacteria. The risk of illness was highest for those who had been on the job 3 months before the outbreak, a time when the humidifier was in constant use. Serologic studies of print shop workers showed positive reactions to extracts of organisms isolated from the humidifier, but could neither distinguish ill from well workers, nor identify causative organisms. The presence of endotoxin-producing bacteria and the clinical syndrome are consistent with an organic dust toxic syndrome. Previous exposure appeared to be the major risk factor for illness.

  19. Outbreak of viral hemorrhagic fever caused by dengue virus type 3 in Al-Mukalla, Yemen.

    PubMed

    Madani, Tariq A; Abuelzein, El-Tayeb M E; Al-Bar, Hussein M S; Azhar, Esam I; Kao, Moujahed; Alshoeb, Haj O; Bamoosa, Alabd R

    2013-03-14

    Investigations were conducted by the authors to explore an outbreak of viral hemorrhagic fever (VHF) reported in 2010 from Al-Mukalla city, the capital of Hadramout in Yemen. From 15-17 June 2010, the outbreak investigation period, specimens were obtained within 7 days after onset of illness of 18 acutely ill patients hospitalized with VHF and 15 household asymptomatic contacts of 6 acute cases. Additionally, 189 stored sera taken from acutely ill patients with suspected VHF hospitalized in the preceding 12 months were obtained from the Ministry of Health of Yemen. Thus, a total of 222 human specimens were collected; 207 specimens from acute cases and 15 specimens from contacts. All samples were tested with RT-PCR for dengue (DENV), Alkhumra (ALKV), Rift Valley Fever (RVFV), Yellow Fever (YFV), and Chikungunya (CHIKV) viruses. Samples were also tested for DENV IgM, IgG, and NS1-antigen. Medical records of patients were reviewed and demographic, clinical, and laboratory data was collected. Of 207 patients tested, 181 (87.4%) patients were confirmed to have acute dengue with positive dengue NS1-antigen (97 patients, 46.9%) and/or IgM (163 patients, 78.7%). Of the 181 patients with confirmed dengue, 100 (55.2%) patients were IgG-positive. DENV RNA was detected in 2 (1%) patients with acute symptoms; both samples were molecularly typed as DENV type 3. No other VHF viruses were detected. For the 15 contacts tested, RT-PCR tests for the five viruses were negative, one contact was dengue IgM positive, and another one was dengue IgG positive. Of the 181 confirmed dengue patients, 120 (66.3%) patients were males and the median age was 24 years. The most common manifestations included fever (100%), headache (94.5%), backache (93.4%), malaise (88.4%), arthralgia (85.1%), myalgia (82.3%), bone pain (77.9%), and leukopenia (76.2%). Two (1.1%) patients died. DENV-3 was confirmed to be the cause of an outbreak of VHF in Al-Mukalla. It is important to use both IgM and NS1-antigen

  20. Outbreak of viral hemorrhagic fever caused by dengue virus type 3 in Al-Mukalla, Yemen

    PubMed Central

    2013-01-01

    Background Investigations were conducted by the authors to explore an outbreak of viral hemorrhagic fever (VHF) reported in 2010 from Al-Mukalla city, the capital of Hadramout in Yemen. Methods From 15–17 June 2010, the outbreak investigation period, specimens were obtained within 7 days after onset of illness of 18 acutely ill patients hospitalized with VHF and 15 household asymptomatic contacts of 6 acute cases. Additionally, 189 stored sera taken from acutely ill patients with suspected VHF hospitalized in the preceding 12 months were obtained from the Ministry of Health of Yemen. Thus, a total of 222 human specimens were collected; 207 specimens from acute cases and 15 specimens from contacts. All samples were tested with RT-PCR for dengue (DENV), Alkhumra (ALKV), Rift Valley Fever (RVFV), Yellow Fever (YFV), and Chikungunya (CHIKV) viruses. Samples were also tested for DENV IgM, IgG, and NS1-antigen. Medical records of patients were reviewed and demographic, clinical, and laboratory data was collected. Results Of 207 patients tested, 181 (87.4%) patients were confirmed to have acute dengue with positive dengue NS1-antigen (97 patients, 46.9%) and/or IgM (163 patients, 78.7%). Of the 181 patients with confirmed dengue, 100 (55.2%) patients were IgG-positive. DENV RNA was detected in 2 (1%) patients with acute symptoms; both samples were molecularly typed as DENV type 3. No other VHF viruses were detected. For the 15 contacts tested, RT-PCR tests for the five viruses were negative, one contact was dengue IgM positive, and another one was dengue IgG positive. Of the 181 confirmed dengue patients, 120 (66.3%) patients were males and the median age was 24 years. The most common manifestations included fever (100%), headache (94.5%), backache (93.4%), malaise (88.4%), arthralgia (85.1%), myalgia (82.3%), bone pain (77.9%), and leukopenia (76.2%). Two (1.1%) patients died. Conclusions DENV-3 was confirmed to be the cause of an outbreak of VHF in Al

  1. 58. Photographic copy of historic medal, The Yellow Fever Medal, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    58. Photographic copy of historic medal, The Yellow Fever Medal, presented to the Portsmouth Naval Hospital by the Town Council of Portsmouth, 1856. (Portsmouth Naval Shipyard Museum, Portsmouth, VA) - Portsmouth Naval Hospital, Hospital Building, Rixey Place, bounded by Williamson Drive, Holcomb Road, & The Circle, Portsmouth, Portsmouth, VA

  2. Prediction of a Rift Valley fever outbreak

    PubMed Central

    Anyamba, Assaf; Chretien, Jean-Paul; Small, Jennifer; Tucker, Compton J.; Formenty, Pierre B.; Richardson, Jason H.; Britch, Seth C.; Schnabel, David C.; Erickson, Ralph L.; Linthicum, Kenneth J.

    2009-01-01

    El Niño/Southern Oscillation related climate anomalies were analyzed by using a combination of satellite measurements of elevated sea-surface temperatures and subsequent elevated rainfall and satellite-derived normalized difference vegetation index data. A Rift Valley fever (RVF) risk mapping model using these climate data predicted areas where outbreaks of RVF in humans and animals were expected and occurred in the Horn of Africa from December 2006 to May 2007. The predictions were subsequently confirmed by entomological and epidemiological field investigations of virus activity in the areas identified as at risk. Accurate spatial and temporal predictions of disease activity, as it occurred first in southern Somalia and then through much of Kenya before affecting northern Tanzania, provided a 2 to 6 week period of warning for the Horn of Africa that facilitated disease outbreak response and mitigation activities. To our knowledge, this is the first prospective prediction of a RVF outbreak. PMID:19144928

  3. Yellow fever disease: density equalizing mapping and gender analysis of international research output

    PubMed Central

    2013-01-01

    Background A number of scientific papers on yellow fever have been published but no broad scientometric analysis on the published research of yellow fever has been reported. The aim of the article based study was to provide an in-depth evaluation of the yellow fever field using large-scale data analysis and employment of bibliometric indicators of production and quantity. Methods Data were retrieved from the Web of Science database (WoS) and analyzed as part of the NewQis platform. Then data were extracted from each file, transferred to databases and visualized as diagrams. Partially by means of density-equalizing mapping makes the findings clear and emphasizes the output of the analysis. Results In the study period from 1900 to 2012 a total of 5,053 yellow fever-associated items were published by 79 countries. The United States (USA) having the highest publication rate at 42% (n = 751) followed by far from Brazil (n = 203), France (n = 149) and the United Kingdom (n = 113). The most productive journals are the “Public Health Reports”, the “American Journal of Tropical Medicine and Hygiene” and the “Journal of Virology”. The gender analysis showed an overall steady increase of female authorship from 1950 to 2011. Brazil is the only country of the five most productive countries with a higher proportion of female scientists. Conclusions The present data shows an increase in research productivity over the entire study period, in particular an increase of female scientists. Brazil shows a majority of female authors, a fact that is confirmed by other studies. PMID:24245856

  4. Trigger events: enviroclimatic coupling of Ebola hemorrhagic fever outbreaks

    NASA Technical Reports Server (NTRS)

    Pinzon, Jorge E.; Wilson, James M.; Tucker, Compton J.; Arthur, Ray; Jahrling, Peter B.; Formenty, Pierre

    2004-01-01

    We use spatially continuous satellite data as a correlate of precipitation within tropical Africa and show that the majority of documented Ebola hemorrhagic fever outbreaks were closely associated with sharply drier conditions at the end of the rainy season. We propose that these trigger events may enhance transmission of Ebola virus from its cryptic reservoir to humans. These findings suggest specific directions to help understand the sylvatic cycle of the virus and may provide early warning tools to detect possible future outbreaks of this enigmatic disease.

  5. A case suspected for yellow fever vaccine-associated viscerotropic disease in the Netherlands.

    PubMed

    van de Pol, Eva M; Gisolf, Elizabeth H; Richter, Clemens

    2014-01-01

    Yellow fever (YF) 17D vaccine is one of the most successful vaccines ever developed. Since 2001, 56 cases of yellow fever vaccine-associated viscerotropic disease (YEL-AVD) have been published in the peer-reviewed literature. Here, we report a new case suspected for YEL-AVD in the Netherlands. Further research is needed to determine the true incidence of YEL-AVD and to clarify host and vaccine-associated factors in the pathogenesis of YEL-AVD. Because of the potential adverse events, healthcare providers should carefully consider vaccination only in people who are truly at risk for YF infection, especially in primary vaccine recipients. © 2014 International Society of Travel Medicine.

  6. Screening test for neutralizing antibodies against yellow fever virus, based on a flavivirus pseudotype.

    PubMed

    Mercier-Delarue, Séverine; Durier, Christine; Colin de Verdière, Nathalie; Poveda, Jean-Dominique; Meiffrédy, Vincent; Fernandez Garcia, Maria Dolores; Lastère, Stéphane; Césaire, Raymond; Manuggera, Jean-Claude; Molina, Jean-Michel; Amara, Ali; Simon, François

    2017-01-01

    Given the possibility of yellow fever virus reintroduction in epidemiologically receptive geographic areas, the risk of vaccine supply disruption is a serious issue. New strategies to reduce the doses of injected vaccines should be evaluated very carefully in terms of immunogenicity. The plaque reduction test for the determination of neutralizing antibodies (PRNT) is particularly time-consuming and requires the use of a confinement laboratory. We have developed a new test based on the use of a non-infectious pseudovirus (WN/YF17D). The presence of a reporter gene allows sensitive determination of neutralizing antibodies by flow cytometry. This WN/YF17D test was as sensitive as PRNT for the follow-up of yellow fever vaccinees. Both tests lacked specificity with sera from patients hospitalized for acute Dengue virus infection. Conversely, both assays were strictly negative in adults never exposed to flavivirus infection or vaccination, and in patients sampled some time after acute Dengue infection. This WN/YF17D test will be particularly useful for large epidemiological studies and for screening for neutralizing antibodies against yellow fever virus.

  7. Mutual interference on the immune response to yellow fever vaccine and a combined vaccine against measles, mumps and rubella.

    PubMed

    Nascimento Silva, Juliana Romualdo; Camacho, Luiz Antonio B; Siqueira, Marilda M; Freire, Marcos de Silva; Castro, Yvone P; Maia, Maria de Lourdes S; Yamamura, Anna Maya Y; Martins, Reinaldo M; Leal, Maria de Luz F

    2011-08-26

    A randomized trial was conducted to assess the immunogenicity and reactogenicity of yellow fever vaccines (YFV) given either simultaneously in separate injections, or 30 days or more after a combined measles-mumps-rubella (MMR) vaccine. Volunteers were also randomized to YFV produced from 17DD and WHO-17D-213 substrains. The study group comprised 1769 healthy 12-month-old children brought to health care centers in Brasilia for routine vaccination. The reactogenicity was of the type and frequency expected for the vaccines and no severe adverse event was associated to either vaccine. Seroconversion and seropositivity 30 days or more after vaccination against yellow fever was similar across groups defined by YFV substrain. Subjects injected YFV and MMR simultaneously had lower seroconversion rates--90% for rubella, 70% for yellow fever and 61% for mumps--compared with those vaccinated 30 days apart--97% for rubella, 87% for yellow fever and 71% for mumps. Seroconversion rates for measles were higher than 98% in both comparison groups. Geometric mean titers for rubella and for yellow fever were approximately three times higher among those who got the vaccines 30 days apart. For measles and mumps antibodies GMTs were similar across groups. MMR's interference in immune response of YFV and YFV's interference in immune response of rubella and mumps components of MMR had never been reported before but are consistent with previous observations from other live vaccines. These results may affect the recommendations regarding primary vaccination with yellow fever vaccine and MMR. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Infection of Mosquito Cells (C6/36) by Dengue-2 Virus Interferes with Subsequent Infection by Yellow Fever Virus.

    PubMed

    Abrao, Emiliana Pereira; da Fonseca, Benedito Antônio Lopes

    2016-02-01

    Dengue is one of the most important diseases caused by arboviruses in the world. Yellow fever is another arthropod-borne disease of great importance to public health that is endemic to tropical regions of Africa and the Americas. Both yellow fever and dengue viruses are flaviviruses transmitted by Aedes aegypti mosquitoes, and then, it is reasonable to consider that in a given moment, mosquito cells could be coinfected by both viruses. Therefore, we decided to evaluate if sequential infections of dengue and yellow fever viruses (and vice-versa) in mosquito cells could affect the virus replication patterns. Using immunofluorescence and real-time PCR-based replication assays in Aedes albopictus C6/36 cells with single or sequential infections with both viruses, we demonstrated the occurrence of viral interference, also called superinfection exclusion, between these two viruses. Our results show that this interference pattern is particularly evident when cells were first infected with dengue virus and subsequently with yellow fever virus (YFV). Reduction in dengue virus replication, although to a lower extent, was also observed when C6/36 cells were initially infected with YFV followed by dengue virus infection. Although the importance that these findings have on nature is unknown, this study provides evidence, at the cellular level, of the occurrence of replication interference between dengue and yellow fever viruses and raises the question if superinfection exclusion could be a possible explanation, at least partially, for the reported lack of urban yellow fever occurrence in regions where a high level of dengue transmission occurs.

  9. Yellow fever vaccination: some thoughts on how much is enough [Vaccine 23 (2005) 3908-3914].

    PubMed

    Martins, Reinaldo M; Galler, Ricardo; Freire, Marcos Silva; Camacho, Luiz Antonio B; de Lourdes S Maia, Maria; Homma, Akira

    2007-01-02

    In a recently published article in this journal, Massad et al. contraindicates yellow fever vaccination to persons 60 years or older, considering that the risk of serious adverse events is higher for this age class. The conclusion was based on the input of available data on age-related probabilities of developing serious adverse events in the United States, as well on other data not firmly established. We consider such contraindication inadequate, because the data input has limitations, higher letality of wild-type yellow fever infection in older adults, risk of introduction of yellow fever by travelers into new countries, lower risk of vaccine adverse events in revaccinated or immune people in endemic countries, and the experience of Brazil, with only one suspect case of associated viscerotropic disease in an individual older than 60 years. The model proposed by Massad et al. is useful but can lead to different conclusions, depending on the epidemiological context and individual risk profile.

  10. Yellow fever in the Americas: the growing concern about new epidemics.

    PubMed

    Ortiz-Martínez, Yeimer; Patiño-Barbosa, Andrés Mauricio; Rodriguez-Morales, Alfonso J

    2017-01-01

    Yellow fever (YF) is a haemorrhagic viral disease with a high case fatality rate. It is considered a reemerging infectious disease of remarkable importance. During the last outbreaks in Brazil (2016-2017), many cases of YF emerged despite high YF vaccination coverage in some areas. However, there are many areas and populations worldwide where vaccination coverage has been low for years (e.g. Nigeria), which increases the risk of major epidemics in such areas, as would be the case in many of the American territories. Several factors, including the vast border and migratory status of Brazil, the widespread distribution of Aedes mosquitoes and the lack of efficient health policies and surveillance systems, favor this complex epidemiological scenario of reemergence. Therefore, mass vaccination of the population at risk, public health awareness and preparedness are urgently needed in this region. This opinion article describes the current global epidemiological situation of YF, focusing especially on the Americas, as well the risk and vulnerabilities in the region that would be of concern for major expansion to other countries apart from Brazil. Also, imported risk from endemic area outside of Americas (i.e. Africa) are of current concern.

  11. Longitudinal myelitis associated with yellow fever vaccination.

    PubMed

    Chaves, M; Riccio, P; Patrucco, L; Rojas, J I; Cristiano, E

    2009-07-01

    Severe adverse reaction to yellow fever (YF) vaccine includes the yellow fever vaccine-associated neurotropic disease. This terminology includes postvaccinal encephalitis, acute disseminated encephalomyelitis, and Guillain-Barré syndrome. The objective of this communication is to report a patient who received a YF vaccine in Argentina and subsequently developed longitudinal myelitis with a symptom that had previously gone unreported in the literature. A 56-year-old man began with progressive paraparesia, urinary retention, and constipation 48 h previous to admission. The patient received YF vaccine 45 days prior to the onset of the symptoms. There was no history of other immunization or relevant condition. MR of the spine showed longitudinal intramedullary hyperintense signal (D5-12) without gadolinium enhancement. A high concentration of YFV-specific IgM vaccine antibody was found in the cerebrospinal fluid (CSF). Serological tests for other flavivirus were negative. A diagnosis of longitudinal myelitis without encephalitis associated with YF vaccine was performed and symptoms improved 5 days later. This is the first report dealing with longitudinal myelitis as a serious adverse event associated with YF vaccination in which confirmation of the presence of antibodies in CSF was found. To date, it is also the first report with serological confirmation in Argentina and in South America. We consider that the present investigation will raise awareness in the region in the reporting of adverse events related to YF vaccine and improve our knowledge of adverse reactions to the vaccine.

  12. The Yellow Fever Vaccine: A History

    PubMed Central

    Frierson, J. Gordon

    2010-01-01

    After failed attempts at producing bacteria-based vaccines, the discovery of a viral agent causing yellow fever and its isolation in monkeys opened new avenues of research. Subsequent advances were the attenuation of the virus in mice and later in tissue culture; the creation of the seed lot system to avoid spontaneous mutations; the ability to produce the vaccine on a large scale in eggs; and the removal of dangerous contaminants. An important person in the story is Max Theiler, who was Professor of Epidemiology and Public Health at Yale from 1964-67, and whose work on virus attenuation created the modern vaccine and earned him the Nobel Prize. PMID:20589188

  13. Lessons Learned from Emergency Response Vaccination Efforts for Cholera, Typhoid, Yellow Fever, and Ebola

    PubMed Central

    Date, Kashmira A.; Sreenivasan, Nandini; Harris, Jennifer B.; Hyde, Terri B.

    2017-01-01

    Countries must be prepared to respond to public health threats associated with emergencies, such as natural disasters, sociopolitical conflicts, or uncontrolled disease outbreaks. Rapid vaccination of populations vulnerable to epidemic-prone vaccine-preventable diseases is a major component of emergency response. Emergency vaccination planning presents challenges, including how to predict resource needs, expand vaccine availability during global shortages, and address regulatory barriers to deliver new products. The US Centers for Disease Control and Prevention supports countries to plan, implement, and evaluate emergency vaccination response. We describe work of the Centers for Disease Control and Prevention in collaboration with global partners to support emergency vaccination against cholera, typhoid, yellow fever, and Ebola, diseases for which a new vaccine or vaccine formulation has played a major role in response. Lessons learned will help countries prepare for future emergencies. Integration of vaccination with emergency response augments global health security through reducing disease burden, saving lives, and preventing spread across international borders. PMID:29155670

  14. How many published cases of serious adverse events after yellow fever vaccination meet Brighton Collaboration diagnostic criteria?

    PubMed

    Thomas, Roger E; Spragins, Wendy; Lorenzetti, Diane L

    2013-12-16

    To perform a systematic review of all serious adverse events (SAEs) after yellow fever vaccination and to assess them according to Brighton Collaboration criteria. Nine electronic databases were searched with the terms "yellow fever vaccine" and "adverse events" to 10 July 2013 (no language/date limits). Two reviewers independently assessed studies, entered data, and assessed cases with Brighton Collaboration criteria. One hundred and thirty-one cases met Brighton Collaboration criteria: 32 anaphylaxis, 41 neurologic (one death), 56 viscerotropic (24 deaths), and 2 both neurologic and viscerotropic criteria. All SAEs occurred following first yellow fever (YF) vaccination. Two additional cases which met Brighton Collaboration criteria were proven due to wild virus. An additional 345 cases were presented with insufficient detail to meet Brighton Collaboration criteria:173 neurological, 68 viscerotropic (24 deaths), 67 anaphylaxis, and 34 cases from a UK database and 3 from a Swiss database described as "serious adverse events" but not further classified into neurologic or viscerotropic. A further 253 cases were excluded as presenting insufficient data to be regarded as yellow fever vaccine (YFV) related SAEs. One hundred and thirty-one cases met Brighton Collaboration criteria for serious adverse events after yellow fever vaccination. Another 345 cases did not meet Brighton criteria and 253 were excluded as presenting insufficient data to be regarded as serious adverse events after YFV. There are likely to be cases in areas that are remote or with insufficient diagnostic resources that are neither correctly assessed nor not published. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Yellow fever risk assessment in the Central African Republic.

    PubMed

    Staples, J Erin; Diallo, Mawlouth; Janusz, Kristen B; Manengu, Casimir; Lewis, Rosamund F; Perea, William; Yactayo, Sergio; Sall, Amadou A

    2014-10-01

    Starting in 2008, the Central African Republic (CAR) experienced an unprecedented number of reported yellow fever (YF) cases. A risk assessment of YF virus (YFV) activity was conducted to estimate potential disease risk and vaccine needs. A multistage cluster sampling design was used to sample humans, non-human primates, and mosquitoes in distinct ecologic zones. Humans and non-human primates were tested for YFV-specific antibodies; mosquitoes were tested for YFV RNA. Overall, 13.3% (125/938) of humans were found to have naturally-acquired YFV antibodies. Antibody levels were higher in zones in the southern and south central regions of CAR. All sampled non-human primates (n=56) were known YFV reservoirs; one tested positive for YFV antibodies. Several known YF vectors were identified including Aedes africanus, Ae. aegypti, Ae. luteocephalus, and Ae. simpsoni. Several more urban locations were found to have elevated Breateau and Container indices for Ae. aegypti. A country-wide assessment of YF risk found YFV to be endemic in CAR. The potential for future YF cases and outbreaks, however, varied by ecologic zone. Improved vaccination coverage through mass campaign and childhood immunization was recommended to mitigate the YF risk. © The Author 2014. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Re-emerging Lassa fever outbreaks in Nigeria: Re-enforcing "One Health" community surveillance and emergency response practice.

    PubMed

    Tambo, Ernest; Adetunde, Oluwasegun T; Olalubi, Oluwasogo A

    2018-04-28

    We evaluated the impact of man-made conflict events and climate change impact in guiding evidence-based community "One Health" epidemiology and emergency response practice against re-/emerging epidemics. Increasing evidence of emerging and re-emerging zoonotic diseases including recent Lassa fever outbreaks in almost 20 states in Nigeria led to 101 deaths and 175 suspected and confirmed cases since August 2015. Of the 75 laboratory confirmed cases, 90 deaths occurred representing 120% laboratory-confirmed case fatality. The outbreak has been imported into neighbouring country such as Benin, where 23 deaths out of 68 cases has also been reported. This study assesses the current trends in re-emerging Lassa fever outbreak in understanding spatio-geographical reservoir(s), risk factors pattern and Lassa virus incidence mapping, inherent gaps and raising challenges in health systems. It is shown that Lassa fever peak endemicity incidence and prevalence overlap the dry season (within January to March) and reduced during the wet season (of May to November) annually in Sierra Leone, Senegal to Eastern Nigeria. We documented a scarcity of consistent data on rodent (reservoirs)-linked Lassa fever outbreak, weak culturally and socio-behavioural effective prevention and control measures integration, weak or limited community knowledge and awareness to inadequate preparedness capacity and access to affordable case management in affected countries. Hence, robust sub/regional leadership commitment and investment in Lassa fever is urgently needed in building integrated and effective community "One Health" surveillance and rapid response approach practice coupled with pest management and phytosanitation measures against Lassa fever epidemic. This offers new opportunities in understanding human-animal interactions in strengthening Lassa fever outbreak early detection and surveillance, warning alerts and rapid response implementation in vulnerable settings. Leveraging on Africa CDC

  17. Detection of yellow fever virus genomes from four imported cases in China.

    PubMed

    Cui, Shujuan; Pan, Yang; Lyu, Yanning; Liang, Zhichao; Li, Jie; Sun, Yulan; Dou, Xiangfeng; Tian, Lili; Huo, Da; Chen, Lijuan; Li, Xinyu; Wang, Quanyi

    2017-07-01

    Yellow fever virus (YFV), as the first proven human-pathogenic virus, is still a major public health problem with a dramatic upsurge in recent years. This is a report on four imported cases of yellow fever virus into China identified by whole genome sequencing. Phylogenetic analysis was performed and the results showed that these four viruses were highly homologous with Angola 71 strains (AY968064). In addition, effective mutations of amino acids were not observed in the E protein domain of four viruses, thus confirming the effectiveness of the YFV-17D vaccine (X03700). Although there is low risk of local transmission in most part of China, the increasing public health risk of YF caused by international exchange should not be ignored. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. Rift Valley fever outbreak, Mauritania, 1998: seroepidemiologic, virologic, entomologic, and zoologic investigations.

    PubMed

    Nabeth, P; Kane, Y; Abdalahi, M O; Diallo, M; Ndiaye, K; Ba, K; Schneegans, F; Sall, A A; Mathiot, C

    2001-01-01

    A Rift Valley fever outbreak occurred in Mauritania in 1998. Seroepidemiologic and virologic investigation showed active circulation of the Rift Valley fever virus, with 13 strains isolated, and 16% (range 1.5%-38%) immunoglobulin (Ig) M-positivity in sera from 90 humans and 343 animals (sheep, goats, camels, cattle, and donkeys). One human case was fatal.

  19. New developments in flavivirus vaccines with special attention to yellow fever.

    PubMed

    Pugachev, Konstantin V; Guirakhoo, Farshad; Monath, Thomas P

    2005-10-01

    Here we review recent epidemiological trends in flavivirus diseases, findings related to existing vaccines, and new directions in flavivirus vaccine research. We emphasize the need for stepped-up efforts to stop further spread and intensification of these infections worldwide. Although the incidence and geographic distribution of flavivirus diseases have increased in recent years, human vaccines are available only for yellow fever, Japanese encephalitis, tick-borne encephalitis and Kyasanur forest disease. Factors contributing to resurgence include insufficient supplies of available vaccines, incomplete vaccination coverage and relaxation in vector control. Research has been underway for 60 years to develop effective vaccines against dengue, and recent progress is encouraging. The development of vaccines against West Nile, virus recently introduced to North America, has been initiated. In addition, there is considerable interest in improving existing vaccines with respect to increasing safety (e.g. eliminating the newly recognized syndrome of yellow fever vaccine-associated viscerotropic adverse disease), and to reducing the cost and number of doses required for effective immunization. Traditional approaches to flavivirus vaccines are still employed, while recent advancements in biotechnology produced new approaches to vaccine design, such as recombinant live virus, subunit and DNA vaccines. Live chimeric vaccines against dengue, Japanese encephalitis and West Nile based on yellow fever 17D virus (ChimeriVax) are in phase I/II trials, with encouraging results. Other chimeric dengue, tick-borne encephalitis and West Nile virus candidates were developed based on attenuated dengue backbones. To further reduce the impact of flavivirus diseases, vaccination policies and vector control programs in affected countries require revision.

  20. Typhoid fever acquired in the United States, 1999-2010: epidemiology, microbiology, and use of a space-time scan statistic for outbreak detection.

    PubMed

    Imanishi, M; Newton, A E; Vieira, A R; Gonzalez-Aviles, G; Kendall Scott, M E; Manikonda, K; Maxwell, T N; Halpin, J L; Freeman, M M; Medalla, F; Ayers, T L; Derado, G; Mahon, B E; Mintz, E D

    2015-08-01

    Although rare, typhoid fever cases acquired in the United States continue to be reported. Detection and investigation of outbreaks in these domestically acquired cases offer opportunities to identify chronic carriers. We searched surveillance and laboratory databases for domestically acquired typhoid fever cases, used a space-time scan statistic to identify clusters, and classified clusters as outbreaks or non-outbreaks. From 1999 to 2010, domestically acquired cases accounted for 18% of 3373 reported typhoid fever cases; their isolates were less often multidrug-resistant (2% vs. 15%) compared to isolates from travel-associated cases. We identified 28 outbreaks and two possible outbreaks within 45 space-time clusters of ⩾2 domestically acquired cases, including three outbreaks involving ⩾2 molecular subtypes. The approach detected seven of the ten outbreaks published in the literature or reported to CDC. Although this approach did not definitively identify any previously unrecognized outbreaks, it showed the potential to detect outbreaks of typhoid fever that may escape detection by routine analysis of surveillance data. Sixteen outbreaks had been linked to a carrier. Every case of typhoid fever acquired in a non-endemic country warrants thorough investigation. Space-time scan statistics, together with shoe-leather epidemiology and molecular subtyping, may improve outbreak detection.

  1. Access to yellow fever travel vaccination centres in England, Wales, and Northern Ireland: A geographical study.

    PubMed

    Petersen, Jakob; Simons, Hilary; Patel, Dipti

    More than 700,000 trips were made by residents in England, Wales, and Northern Ireland (EWNI) in 2015 to tropical countries endemic for yellow fever, a potentially deadly, yet vaccine-preventable disease transmitted by mosquitoes. The aim of this study was to map the geographical accessibility of yellow fever vaccination centres (YFVC) in EWNI. The location of 3208 YFVC were geocoded and the average geodetic distance to nearest YFVC was calculated for each population unit. Data on trips abroad and centres were obtained regionally for EWNI and nationally for the World Top20 countries in terms of travel. The mean distance to nearest YFVC was 2.4 km and only 1% of the population had to travel more than 16.1 km to their nearest centre. The number of vaccines administered regionally in EWNI was found correlated with the number of trips to yellow fever countries. The number of centres per 100,000 trips was 6.1 in EWNI, which was below United States (12.1) and above the rest of Top20 countries. The service availability was in line with demand regionally. With the exception of remote, rural areas, yellow fever vaccination services were widely available with only short distances to cover for the travelling public. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  2. Entomological investigation of a sylvatic yellow fever area in São Paulo State, Brazil.

    PubMed

    Camargo-Neves, Vera L F de; Poletto, Daniela W; Rodas, Lílian A C; Pachioli, Márcio L; Cardoso, Rubens P; Scandar, Sirle A S; Sampaio, Susy M P; Koyanagui, Paulo H; Botti, Mauricio V; Mucci, Luis F; Gomes, Almério de C

    2005-01-01

    Following reports of two autochthonous cases of sylvatic yellow fever in the State of São Paulo, Brazil, in 2000, entomological surveys were conducted with the objective of verifying the occurrence of vector species in forest environments close to or associated with riparian areas located in the western and northwestern regions of the State. Culicidae were captured in 39 sites distributed in four regions. Haemagogus leucocelaenus and Aedes albopictus were the most abundant species and were captured in all the regions studied. H. leucocelaenus was the most abundant species in the municipalities of Santa Albertina and Ouroeste, where the two cases of sylvatic yellow fever had been reported. Mosquitoes from the janthinomys/capricornii group were only found at eight sites in the São José do Rio Preto region, while Sabethes chloropterus was found at one site in Ribeirão Preto. H. leucocelaenus showed its capacity to adapt to a secondary and degraded environment. Our results indicate a wide receptive area for yellow fever transmission in the State of São Paulo, with particular emphasis on the possibility of H. leucocelaenus being involved in the maintenance of this sylvatic focus of the disease.

  3. 17DD yellow fever vaccine: a double blind, randomized clinical trial of immunogenicity and safety on a dose-response study.

    PubMed

    Martins, Reinaldo M; Maia, Maria de Lourdes S; Farias, Roberto Henrique G; Camacho, Luiz Antonio B; Freire, Marcos S; Galler, Ricardo; Yamamura, Anna Maya Yoshida; Almeida, Luiz Fernando C; Lima, Sheila Maria B; Nogueira, Rita Maria R; Sá, Gloria Regina S; Hokama, Darcy A; de Carvalho, Ricardo; Freire, Ricardo Aguiar V; Pereira Filho, Edson; Leal, Maria da Luz Fernandes; Homma, Akira

    2013-04-01

    To verify if the Bio-Manguinhos 17DD yellow fever vaccine (17DD-YFV) used in lower doses is as immunogenic and safe as the current formulation. Doses from 27,476 IU to 587 IU induced similar seroconversion rates and neutralizing antibodies geometric mean titers (GMTs). Immunity of those who seroconverted to YF was maintained for 10 mo. Reactogenicity was low for all groups. Young and healthy adult males (n = 900) were recruited and randomized into 6 groups, to receive de-escalating doses of 17DD-YFV, from 27,476 IU to 31 IU. Blood samples were collected before vaccination (for neutralization tests to yellow fever, serology for dengue and clinical chemistry), 3 to 7 d after vaccination (for viremia and clinical chemistry) and 30 d after vaccination (for new yellow fever serology and clinical chemistry). Adverse events diaries were filled out by volunteers during 10 d after vaccination. Volunteers were retested for yellow fever and dengue antibodies 10 mo later. Seropositivity for dengue was found in 87.6% of volunteers before vaccination, but this had no significant influence on conclusions. In young healthy adults Bio-Manguinhos/Fiocruz yellow fever vaccine can be used in much lower doses than usual. INTERNATIONAL REGISTER: ISRCTN 38082350.

  4. An Outbreak of Ebola Virus Disease in the Lassa Fever Zone

    PubMed Central

    Goba, Augustine; Khan, S. Humarr; Fonnie, Mbalu; Fullah, Mohamed; Moigboi, Alex; Kovoma, Alice; Sinnah, Vandi; Yoko, Nancy; Rogers, Hawa; Safai, Siddiki; Momoh, Mambu; Koroma, Veronica; Kamara, Fatima K.; Konowu, Edwin; Yillah, Mohamed; French, Issa; Mustapha, Ibraham; Kanneh, Franklyn; Foday, Momoh; McCarthy, Helena; Kallon, Tiangay; Kallon, Mustupha; Naiebu, Jenneh; Sellu, Josephine; Jalloh, Abdul A.; Gbakie, Michael; Kanneh, Lansana; Massaly, James L. B.; Kargbo, David; Kargbo, Brima; Vandi, Mohamed; Gbetuwa, Momoh; Gevao, Sahr M.; Sandi, John D.; Jalloh, Simbirie C.; Grant, Donald S.; Blyden, Sylvia O.; Crozier, Ian; Schieffelin, John S.; McLellan, Susan L.; Jacob, Shevin T.; Boisen, Matt L.; Hartnett, Jessica N.; Cross, Robert W.; Branco, Luis M.; Andersen, Kristian G.; Yozwiak, Nathan L.; Gire, Stephen K.; Tariyal, Ridhi; Park, Daniel J.; Haislip, Allyson M.; Bishop, Christopher M.; Melnik, Lilia I.; Gallaher, William R.; Wimley, William C.; He, Jing; Shaffer, Jeffrey G.; Sullivan, Brian M.; Grillo, Sonia; Oman, Scott; Garry, Courtney E.; Edwards, Donna R.; McCormick, Stephanie J.; Elliott, Deborah H.; Rouelle, Julie A.; Kannadka, Chandrika B.; Reyna, Ashley A.; Bradley, Benjamin T.; Yu, Haini; Yenni, Rachael E.; Hastie, Kathryn M.; Geisbert, Joan B.; Kulakosky, Peter C.; Wilson, Russell B.; Oldstone, Michael B. A.; Pitts, Kelly R.; Henderson, Lee A.; Robinson, James E.; Geisbert, Thomas W.; Saphire, Erica Ollmann; Happi, Christian T.; Asogun, Danny A.; Sabeti, Pardis C.; Garry, Robert F.

    2016-01-01

    Background. Kenema Government Hospital (KGH) has developed an advanced clinical and laboratory research capacity to manage the threat of Lassa fever, a viral hemorrhagic fever (VHF). The 2013–2016 Ebola virus (EBOV) disease (EVD) outbreak is the first to have occurred in an area close to a facility with established clinical and laboratory capacity for study of VHFs. Methods. Because of its proximity to the epicenter of the EVD outbreak, which began in Guinea in March 2014, the KGH Lassa fever Team mobilized to establish EBOV surveillance and diagnostic capabilities. Results. Augustine Goba, director of the KGH Lassa laboratory, diagnosed the first documented case of EVD in Sierra Leone, on 25 May 2014. Thereafter, KGH received and cared for numbers of patients with EVD that quickly overwhelmed the capacity for safe management. Numerous healthcare workers contracted and lost their lives to EVD. The vast majority of subsequent EVD cases in West Africa can be traced back to a single transmission chain that includes this first diagnosed case. Conclusions. Responding to the challenges of confronting 2 hemorrhagic fever viruses will require continued investments in the development of countermeasures (vaccines, therapeutic agents, and diagnostic assays), infrastructure, and human resources. PMID:27402779

  5. THE SURVIVAL OF YELLOW FEVER VIRUS IN CULTURES

    PubMed Central

    Lewis, Paul A.

    1930-01-01

    1. The virus of yellow fever has been found to survive in artificial culture media for at least 12 days at a temperature of 35°C. No visible growth has been present and no reproduction of the virus has been demonstrated. 2. Infections have been obtained in rhesus monkeys with two strains of virus in quantities as small as 0.00001 cc. of infectious blood, and with one strain in an amount probably as minute as 0.000001 cc. PMID:19869744

  6. Vaccines and vaccination against yellow fever: WHO Position Paper, June 2013--recommendations.

    PubMed

    2015-01-01

    This article presents the World Health Organizations (WHO) evidence and recommendations for the use of yellow fever (YF) vaccination from "Vaccines and vaccination against yellow fever: WHO Position Paper - June 2013" published in the Weekly Epidemiological Record. This position paper summarizes the WHO position on the use of YF vaccination, in particular that a single dose of YF vaccine is sufficient to confer sustained life-long protective immunity against YF disease. A booster dose is not necessary. The current document replaces the position paper on the use of yellow fever vaccines and vaccination published in 2003. Footnotes to this paper provide a number of core references. In accordance with its mandate to provide guidance to Member States on health policy matters, WHO issues a series of regularly updated position papers on vaccines and combinations of vaccines against diseases that have an international public health impact. These papers are concerned primarily with the use of vaccines in large-scale immunization programmes; they summarize essential background information on diseases and vaccines, and conclude with WHO's current position on the use of vaccines in the global context. This paper reflects the recommendations of WHO's Strategic Advisory Group of Experts (SAGE) on immunization. These recommendations were discussed by SAGE at its April 2013 meeting. Evidence presented at the meeting can be accessed at http://www.who.int/immunization/sage/previous/en/index.html. Copyright © 2014. Published by Elsevier Ltd.

  7. The whole iceberg: estimating the incidence of yellow fever virus infection from the number of severe cases.

    PubMed

    Johansson, Michael A; Vasconcelos, Pedro F C; Staples, J Erin

    2014-08-01

    Like many infectious agents, yellow fever (YF) virus only causes disease in a proportion of individuals it infects and severe illness only represents the tip of the iceberg relative to the total number of infections, the more critical factor for virus transmission. We compiled data on asymptomatic infections, mild disease, severe disease (fever with jaundice or hemorrhagic symptoms) and fatalities from 11 studies in Africa and South America between 1969 and 2011. We used a Bayesian model to estimate the probability of each infection outcome. For YF virus infections, the probability of being asymptomatic was 0.55 (95% credible interval [CI] 0.37-0.74), mild disease 0.33 (95% CI 0.13-0.52) and severe disease 0.12 (95% CI 0.05-0.26). The probability of death for people experiencing severe disease was 0.47 (95% CI 0.31-0.62). In outbreak situations where only severe cases may initially be detected, we estimated that there may be between one and seventy infections that are either asymptomatic or cause mild disease for every severe case identified. As it is generally only the most severe cases that are recognized and reported, these estimates will help improve the understanding of the burden of disease and the estimation of the potential risk of spread during YF outbreaks. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  8. A Large-Scale Community-Based Outbreak of Paratyphoid Fever Caused by Hospital-Derived Transmission in Southern China.

    PubMed

    Yan, Meiying; Yang, Bo; Wang, Zhigang; Wang, Shukun; Zhang, Xiaohe; Zhou, Yanhua; Pang, Bo; Diao, Baowei; Yang, Rusong; Wu, Shuyu; Klena, John D; Kan, Biao

    2015-01-01

    Since the 1990s, paratyphoid fever caused by Salmonella Paratyphi A has emerged in Southeast Asia and China. In 2010, a large-scale outbreak involving 601 cases of paratyphoid fever occurred in the whole of Yuanjiang county in China. Epidemiological and laboratory investigations were conducted to determine the etiology, source and transmission factors of the outbreak. A case-control study was performed to identify the risk factors for this paratyphoid outbreak. Cases were identified as patients with blood culture-confirmed S. Paratyphi A infection. Controls were healthy persons without fever within the past month and matched to cases by age, gender and geography. Pulsed-field gel electrophoresis and whole-genome sequencing of the S. Paratyphi A strains isolated from patients and environmental sources were performed to facilitate transmission analysis and source tracking. We found that farmers and young adults were the populations mainly affected in this outbreak, and the consumption of raw vegetables was the main risk factor associated with paratyphoid fever. Molecular subtyping and genome sequencing of S. Paratyphi A isolates recovered from improperly disinfected hospital wastewater showed indistinguishable patterns matching most of the isolates from the cases. An investigation showed that hospital wastewater mixed with surface water was used for crop irrigation, promoting a cycle of contamination. After prohibition of the planting of vegetables in contaminated fields and the thorough disinfection of hospital wastewater, the outbreak subsided. Further analysis of the isolates indicated that the origin of the outbreak was most likely from patients outside Yuanjiang county. This outbreak is an example of the combined effect of social behaviors, prevailing ecological conditions and improper disinfection of hospital wastewater on facilitating a sustained epidemic of paratyphoid fever. This study underscores the critical need for strict treatment measures of hospital

  9. Yellow fever in Pará State, Amazon region of Brazil, 1998-1999: entomologic and epidemiologic findings.

    PubMed

    Vasconcelos, P F; Rosa, A P; Rodrigues, S G; Rosa, E S; Monteiro, H A; Cruz, A C; Barros, V L; Souza, M R; Rosa, J F

    2001-01-01

    Yellow fever (YF) is frequently associated with high severity and death rates in the Amazon region of Brazil. During the rainy seasons of 1998 and 1999, 23 (eight deaths) and 34 (eight deaths) human cases of YF were reported, respectively, in different geographic areas of Pará State; most cases were on Marajó Island. Patients were 1 to 46 years of age. Epidemiologic and ecological studies were conducted in Afuá and Breves on Marajó Island; captured insects yielded isolates of 4 and 11 YF strains, respectively, from Haemagogus janthinomys pooled mosquitoes. The cases on Marajó Island in 1999 resulted from lack of vaccination near the focus of the disease and intense migration, which brought many nonimmune people to areas where infected vectors were present. We hypothesize that YF virus remains in an area after an outbreak by vertical transmission among Haemagogus mosquitoes.

  10. The seasonal influence of climate and environment on yellow fever transmission across Africa

    PubMed Central

    Hamlet, Arran; Perea, William; Yactayo, Sergio; Biey, Joseph; Van Kerkhove, Maria; Ferguson, Neil

    2018-01-01

    Background Yellow fever virus (YFV) is a vector-borne flavivirus endemic to Africa and Latin America. Ninety per cent of the global burden occurs in Africa where it is primarily transmitted by Aedes spp, with Aedes aegypti the main vector for urban yellow fever (YF). Mosquito life cycle and viral replication in the mosquito are heavily dependent on climate, particularly temperature and rainfall. We aimed to assess whether seasonal variations in climatic factors are associated with the seasonality of YF reports. Methodology/Principal findings We constructed a temperature suitability index for YFV transmission, capturing the temperature dependence of mosquito behaviour and viral replication within the mosquito. We then fitted a series of multilevel logistic regression models to a dataset of YF reports across Africa, considering location and seasonality of occurrence for seasonal models, against the temperature suitability index, rainfall and the Enhanced Vegetation Index (EVI) as covariates alongside further demographic indicators. Model fit was assessed by the Area Under the Curve (AUC), and models were ranked by Akaike’s Information Criterion which was used to weight model outputs to create combined model predictions. The seasonal model accurately captured both the geographic and temporal heterogeneities in YF transmission (AUC = 0.81), and did not perform significantly worse than the annual model which only captured the geographic distribution. The interaction between temperature suitability and rainfall accounted for much of the occurrence of YF, which offers a statistical explanation for the spatio-temporal variability in transmission. Conclusions/Significance The description of seasonality offers an explanation for heterogeneities in the West-East YF burden across Africa. Annual climatic variables may indicate a transmission suitability not always reflected in seasonal interactions. This finding, in conjunction with forecasted data, could highlight areas of

  11. Biological and phylogenetic characteristics of yellow fever virus lineages from West Africa.

    PubMed

    Stock, Nina K; Laraway, Hewád; Faye, Ousmane; Diallo, Mawlouth; Niedrig, Matthias; Sall, Amadou A

    2013-03-01

    The yellow fever virus (YFV), the first proven human-pathogenic virus, although isolated in 1927, is still a major public health problem, especially in West Africa where it causes outbreaks every year. Nevertheless, little is known about its genetic diversity and evolutionary dynamics, mainly due to a limited number of genomic sequences from wild virus isolates. In this study, we analyzed the phylogenetic relationships of 24 full-length genomes from YFV strains isolated between 1973 and 2005 in a sylvatic context of West Africa, including 14 isolates that had previously not been sequenced. By this, we confirmed genetic variability within one genotype by the identification of various YF lineages circulating in West Africa. Further analyses of the biological properties of these lineages revealed differential growth behavior in human liver and insect cells, correlating with the source of isolation and suggesting host adaptation. For one lineage, repeatedly isolated in a context of vertical transmission, specific characteristics in the growth behavior and unique mutations of the viral genome were observed and deserve further investigation to gain insight into mechanisms involved in YFV emergence and maintenance in nature.

  12. Biological and Phylogenetic Characteristics of Yellow Fever Virus Lineages from West Africa

    PubMed Central

    Laraway, Hewád; Faye, Ousmane; Diallo, Mawlouth; Niedrig, Matthias

    2013-01-01

    The yellow fever virus (YFV), the first proven human-pathogenic virus, although isolated in 1927, is still a major public health problem, especially in West Africa where it causes outbreaks every year. Nevertheless, little is known about its genetic diversity and evolutionary dynamics, mainly due to a limited number of genomic sequences from wild virus isolates. In this study, we analyzed the phylogenetic relationships of 24 full-length genomes from YFV strains isolated between 1973 and 2005 in a sylvatic context of West Africa, including 14 isolates that had previously not been sequenced. By this, we confirmed genetic variability within one genotype by the identification of various YF lineages circulating in West Africa. Further analyses of the biological properties of these lineages revealed differential growth behavior in human liver and insect cells, correlating with the source of isolation and suggesting host adaptation. For one lineage, repeatedly isolated in a context of vertical transmission, specific characteristics in the growth behavior and unique mutations of the viral genome were observed and deserve further investigation to gain insight into mechanisms involved in YFV emergence and maintenance in nature. PMID:23269797

  13. Patterns of a sylvatic yellow fever virus amplification in southeastern Senegal, 2010.

    PubMed

    Diallo, Diawo; Sall, Amadou A; Diagne, Cheikh T; Faye, Oumar; Hanley, Kathryn A; Buenemann, Michaela; Ba, Yamar; Faye, Ousmane; Weaver, Scott C; Diallo, Mawlouth

    2014-06-01

    During the wet season of 2010, yellow fever virus (YFV) was detected in field-collected mosquitoes in the Kédougou region in southeastern Senegal. During this outbreak, we studied the association of the abundance of YFV-infected mosquitoes and land cover features to try and understand the dynamics of YFV transmission within the region. In total, 41,234 mosquito females were collected and tested for virus infection in 5,152 pools. YFV was detected in 67 pools; species including Aedes furcifer (52.2% of the infected pools), Ae. luteocephalus (31.3% of the infected pools), Ae. taylori (6.0% of the infected pools) and six other species (10.4% of the infected pools) captured in September (13.4%), October (70.1%), and November (16.4%). Spatially, YFV was detected from mosquitoes collected in all land cover classes but mainly, forest canopies (49.2%). Human infection is likely mediated by Ae. furcifer, the only species found infected with YFV within villages. Villages containing YFV-infected mosquitoes were significantly closer to large forests (> 2 ha) than villages in which no infected mosquitoes were detected. © The American Society of Tropical Medicine and Hygiene.

  14. Typhoid fever acquired in the United States, 1999–2010: epidemiology, microbiology, and use of a space–time scan statistic for outbreak detection

    PubMed Central

    IMANISHI, M.; NEWTON, A. E.; VIEIRA, A. R.; GONZALEZ-AVILES, G.; KENDALL SCOTT, M. E.; MANIKONDA, K.; MAXWELL, T. N.; HALPIN, J. L.; FREEMAN, M. M.; MEDALLA, F.; AYERS, T. L.; DERADO, G.; MAHON, B. E.; MINTZ, E. D.

    2016-01-01

    SUMMARY Although rare, typhoid fever cases acquired in the United States continue to be reported. Detection and investigation of outbreaks in these domestically acquired cases offer opportunities to identify chronic carriers. We searched surveillance and laboratory databases for domestically acquired typhoid fever cases, used a space–time scan statistic to identify clusters, and classified clusters as outbreaks or non-outbreaks. From 1999 to 2010, domestically acquired cases accounted for 18% of 3373 reported typhoid fever cases; their isolates were less often multidrug-resistant (2% vs. 15%) compared to isolates from travel-associated cases. We identified 28 outbreaks and two possible outbreaks within 45 space–time clusters of ⩾2 domestically acquired cases, including three outbreaks involving ⩾2 molecular subtypes. The approach detected seven of the ten outbreaks published in the literature or reported to CDC. Although this approach did not definitively identify any previously unrecognized outbreaks, it showed the potential to detect outbreaks of typhoid fever that may escape detection by routine analysis of surveillance data. Sixteen outbreaks had been linked to a carrier. Every case of typhoid fever acquired in a non-endemic country warrants thorough investigation. Space–time scan statistics, together with shoe-leather epidemiology and molecular subtyping, may improve outbreak detection. PMID:25427666

  15. Functional Characterization of the Octenol Receptor Neuron on the Maxillary Palps of the Yellow Fever Mosquito, Aedes aegypti

    DTIC Science & Technology

    2011-06-30

    Functional Characterization of the Octenol Receptor Neuron on the Maxillary Palps of the Yellow Fever Mosquito, Aedes aegypti Alan J. Grant, Joseph C...Dickens JC (2011) Functional Characterization of the Octenol Receptor Neuron on the Maxillary Palps of the Yellow Fever Mosquito, Aedes aegypti . PLoS...palps. Both sexes of mosquitoes possess basiconic sensilla that contain three neurons; in Aedes aegypti these sensilla number about 35 in females and 21

  16. Report and analysis of a scarlet fever outbreak among adults through food-borne transmission in China.

    PubMed

    Yang, Shi-Gui; Dong, Hong-Jun; Li, Fu-Rong; Xie, Shu-Yun; Cao, Hong-Cui; Xia, Shi-Chang; Yu, Zhao; Li, Lan-Juan

    2007-11-01

    Scarlet fever is caused by group A beta-hemolytic streptococci (GAS). The clinical syndrome has receded in recent years, but occasionally explosive outbreaks do occur likely due to the emergence of GAS with virulence factors peculiar to this syndrome. Following the notification of an unexpectedly large number of scarlet fever cases amongst adults associated with a school in Ningbo, China, in June 2006, the epidemiological and clinical features of the outbreak were investigated. Logistic regression was conducted to investigate the risk factors of the outbreak and its transmission route. Forty five individuals suffered scarlet fever with an attack rate of 4.98% (45/904). There was a single peak in the epidemic curve, with the majority of the cases occurring during the first two days of the outbreak. The median age of cases was 35.5 years (range 17-65). Most patients had fever (43/45), sore throat (40/45), scarlatinoid rash (39/45) and strawberry-like tongue (30/45). In laboratory detection, 45 cases' throat swabs samples were collected and GAS were isolated from 8 throat swabs samples. All of the cases, except for 2, had eaten the Plain Boiled Chicken (PBC) for lunch on June 6th, and teaching staff and students who had not eaten the PBC were not affected by the epidemic. Logistic regression analysis indicated that PBC was a key risk factor (OR=21.0, P<0.05). The chef of the school refectory was responsible for washing, braising, cutting, and distributing the PBC, and was identified as the likely source. We describe an outbreak of scarlet fever caused by GAS-contaminated food.

  17. An international point source outbreak of typhoid fever: a European collaborative investigation*

    PubMed Central

    Stanwell-Smith, R. E.; Ward, L. R.

    1986-01-01

    A point source outbreak of Salmonella typhi, degraded Vi-strain 22, affecting 32 British visitors to Kos, Greece, in 1983 was attributed by a case—control study to the consumption of a salad at one hotel. This represents the first major outbreak of typhoid fever in which a salad has been identified as the vehicle. The source of the infection was probably a carrier in the hotel staff. The investigation demonstrates the importance of national surveillance, international cooperation, and epidemiological methods in the investigation and control of major outbreaks of infection. PMID:3488842

  18. Impact of yellow fever on the developing world.

    PubMed

    Tomori, O

    1999-01-01

    Yellow fever (YF) has remained a disease of public health importance since it was first described in the fifteenth century. At different periods in human history, YF has caused untold hardship and indescribable misery among populations in the Americas, Europe, and Africa. It brought economic disaster in its wake, constituting a stumbling block to development. Yellow fever is an arboviral infection with three epidemiological transmission cycles between monkeys, mosquitoes, and humans. It is an acute infectious disease characterized by sudden onset, with two phases of development separated by a short period of remission. The clinical spectrum of YF varies from a very mild, nonspecific, febrile illness to a fulminating, sometimes fatal disease with pathognomonic features. In severe cases, jaundice and bleeding diathesis with hepatorenal involvement are common. The fatality rate of severe YF is 50% or higher. Despite landmark achievements in the understanding of the epidemiology of YF and the availability of a safe, efficacious vaccine, YF remains a major public health problem in both Africa and South America, where annually the disease affects an estimated 200,000 persons, causing an estimated 30,000 deaths. Since the 1980s epidemics of YF in Africa have affected predominantly children under the age of 15 years. The failure to control YF arises from a misapplication of public health strategies and insufficient political commitment by governments in YF endemic areas, especially in Africa, to control the disease.

  19. An Outbreak of Ebola Virus Disease in the Lassa Fever Zone.

    PubMed

    Goba, Augustine; Khan, S Humarr; Fonnie, Mbalu; Fullah, Mohamed; Moigboi, Alex; Kovoma, Alice; Sinnah, Vandi; Yoko, Nancy; Rogers, Hawa; Safai, Siddiki; Momoh, Mambu; Koroma, Veronica; Kamara, Fatima K; Konowu, Edwin; Yillah, Mohamed; French, Issa; Mustapha, Ibraham; Kanneh, Franklyn; Foday, Momoh; McCarthy, Helena; Kallon, Tiangay; Kallon, Mustupha; Naiebu, Jenneh; Sellu, Josephine; Jalloh, Abdul A; Gbakie, Michael; Kanneh, Lansana; Massaly, James L B; Kargbo, David; Kargbo, Brima; Vandi, Mohamed; Gbetuwa, Momoh; Gevao, Sahr M; Sandi, John D; Jalloh, Simbirie C; Grant, Donald S; Blyden, Sylvia O; Crozier, Ian; Schieffelin, John S; McLellan, Susan L; Jacob, Shevin T; Boisen, Matt L; Hartnett, Jessica N; Cross, Robert W; Branco, Luis M; Andersen, Kristian G; Yozwiak, Nathan L; Gire, Stephen K; Tariyal, Ridhi; Park, Daniel J; Haislip, Allyson M; Bishop, Christopher M; Melnik, Lilia I; Gallaher, William R; Wimley, William C; He, Jing; Shaffer, Jeffrey G; Sullivan, Brian M; Grillo, Sonia; Oman, Scott; Garry, Courtney E; Edwards, Donna R; McCormick, Stephanie J; Elliott, Deborah H; Rouelle, Julie A; Kannadka, Chandrika B; Reyna, Ashley A; Bradley, Benjamin T; Yu, Haini; Yenni, Rachael E; Hastie, Kathryn M; Geisbert, Joan B; Kulakosky, Peter C; Wilson, Russell B; Oldstone, Michael B A; Pitts, Kelly R; Henderson, Lee A; Robinson, James E; Geisbert, Thomas W; Saphire, Erica Ollmann; Happi, Christian T; Asogun, Danny A; Sabeti, Pardis C; Garry, Robert F

    2016-10-15

     Kenema Government Hospital (KGH) has developed an advanced clinical and laboratory research capacity to manage the threat of Lassa fever, a viral hemorrhagic fever (VHF). The 2013-2016 Ebola virus (EBOV) disease (EVD) outbreak is the first to have occurred in an area close to a facility with established clinical and laboratory capacity for study of VHFs.  Because of its proximity to the epicenter of the EVD outbreak, which began in Guinea in March 2014, the KGH Lassa fever Team mobilized to establish EBOV surveillance and diagnostic capabilities.  Augustine Goba, director of the KGH Lassa laboratory, diagnosed the first documented case of EVD in Sierra Leone, on 25 May 2014. Thereafter, KGH received and cared for numbers of patients with EVD that quickly overwhelmed the capacity for safe management. Numerous healthcare workers contracted and lost their lives to EVD. The vast majority of subsequent EVD cases in West Africa can be traced back to a single transmission chain that includes this first diagnosed case.  Responding to the challenges of confronting 2 hemorrhagic fever viruses will require continued investments in the development of countermeasures (vaccines, therapeutic agents, and diagnostic assays), infrastructure, and human resources. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  20. [Yellow fever vaccination in non-immunocompetent patients].

    PubMed

    Bruyand, M; Receveur, M C; Pistone, T; Verdière, C H; Thiebaut, R; Malvy, D

    2008-10-01

    Any person travelling in countries where yellow fever (YF) is endemic and without presenting contra-indication for the vaccination against YF may be vaccinated. This vaccination can very rarely induce a potentially lethal neurotropic or viscerotropic disease. In severely immunodeficient patients, the vaccination is contra-indicated because postvaccinal encephalitis may occur after the vaccination, due to vaccine strain pathogenecity. It is important to evaluate the general health status in elderly individuals before vaccinating because of the increased risk of viscerotropic disease in people of 60 years of age and over. Pregnant women should not be vaccinated, except if departure to an endemic zone is unavoidable. YF vaccinatio is contra-indicated for newborns under six months of age. Solid organ grafts, congenital immunodeficiency, leukemia, lymphoma, cancer, and immunosuppressive treatments are contra-indications for this vaccination. Nevertheless, YF immunization is possible after a bone marrow graft and a two-year period without graft-versus-host disease or immunosuppressive treatment. There is no data to support that immunization of the dono prior to the graft could confer protection against yellow fever to the recipient. Low doses, short courses of corticosteroids either as systemic treatment or intra-articular injections are not contra-indications for YF vaccination. Patients infected with HIV with stable clinical status and T CD4-cel count above 200 cells per millimetre cube may be vaccinated. Thymic diseases, including thymoma and thymectomy, are contra-indications for YF vaccination. Finally, a substantial residual level of antibodies beyond 10 years after the latest vaccination could confer protection, thus avoiding a new vaccination when it is an issue.

  1. Collaborative study to assess the suitability of a candidate International Standard for yellow fever vaccine.

    PubMed

    Ferguson, Morag; Heath, Alan

    2004-12-01

    Yellow fever vaccines are routinely assayed by plaque assay. However, the results of these assays are then converted into mouse LD(50) using correlations/conversion factors which, in many cases, were established many years ago. The minimum required potency in WHO Recommendations is 10(3) LD(50)/dose. Thirteen participants from 8 countries participated in a collaborative study whose aim was to assess the suitability of two candidate preparations to serve as an International Standard for yellow fever vaccine. In addition, the study investigated the relationship between the mouse LD(50) test and plaque forming units with a view to updating the WHO recommendations. Plaque assays were more reproducible than mouse assays, as expected. Differences in sensitivities of plaque assays were observed between laboratories but these differences appear to be consistent within a laboratory for all samples and the expression of potency relative to the candidate standard vaccine improved the reproducibility of assays between laboratories. However, the use of potencies had little effect on the between laboratory variability in mouse LD(50) assays. There appears to be a consistent relationship between overall mean LD(50) and plaques titre for all study preparations other than sample E. The slope of the correlation curve is >1 and it would appear that 10(3) LD(50) is approximately equivalent to 10(4) plaque forming units (PFU), based on the overall means of all laboratory results. The First International Standard for yellow fever vaccine, NIBSC Code 99/616, has been established as the First International Standard for yellow fever vaccine by the Expert Committee of Biological Standards of the World Health Organisation. The International Standard has been arbitrarily assigned a potency of 10(4.5) International Units (IU) per ampoule. Manufacturers and National Control Laboratories are including the First International Standard for yellow fever vaccine in routine assays so that the minimum

  2. The centennial of the Yellow Fever Commission and the use of informed consent in medical research.

    PubMed

    Güereña-Burgueño, Fernando

    2002-01-01

    The year 2000 marked the centennial of the discovery of the mode of transmission of yellow fever. Informed consent was systematically used for the first time in research. This process was the result of a complex social phenomenon involving the American Public Health Association, the US and Spanish Governments, American and Cuban scientists, the media, and civilian and military volunteers. The public health and medical communities face the AIDS pandemic at the beginning of the 21st Century, as they faced the yellow fever epidemic at the beginning of the 20th Century. Current medical research dilemmas have fueled the debate about the ethical conduct of research in human subjects. The AIDS pandemic is imposing enormous new ethical challenges on the conduct of medical research, especially in the developing world. Reflecting on the yellow fever experiments of 1900, lessons can be learned and applied to the current ethical challenges faced by the international public health research community. The English version of this paper is available too at: http://www.insp.mx/salud/index.html.

  3. Risk groups for yellow fever vaccine-associated viscerotropic disease (YEL-AVD).

    PubMed

    Seligman, Stephen J

    2014-10-07

    Although previously considered as the safest of the live virus vaccines, reports published since 2001 indicate that live yellow fever virus vaccine can cause a severe, often fatal, multisystemic illness, yellow fever vaccine-associated viscerotropic disease (YEL-AVD), that resembles the disease it was designed to prevent. This review was prompted by the availability of a listing of the cumulative cases of YEL-AVD, insights from a statistical method for analyzing risk factors and re-evaluation of previously published data. The purpose of this review is to identify and analyze risk groups based on gender, age, outcome and predisposing illnesses. Using a passive surveillance system in the US, the incidence was reported as 0.3 to 0.4 cases per 100,000. However, other estimates range from 0 to 12 per 100,000. Identified and potential risk groups for YEL-AVD include elderly males, women between the ages of 19 and 34, people with a variety of autoimmune diseases, individuals who have been thymectomized because of thymoma, and infants and children ≤11 years old. All but the last group are supported by statistical analysis. The confirmed risk groups account for 77% (49/64) of known cases and 76% (32/42) of the deaths. The overall case fatality rate is 66% (42/64) with a rate of 80% (12/15) in young women, in contrast to 50% (13/26) in men ≥56 years old. Recognition of YEL-AVD raises the possibility that similar reactions to live chimeric flavivirus vaccines that contain a yellow fever virus vaccine backbone could occur in susceptible individuals. Delineation of risk groups focuses the search for genetic mutations resulting in immune defects associated with a given risk group. Lastly, identification of risk groups encourages concentration on measures to decrease both the incidence and the severity of YEL-AVD. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. [Antibody responses in Japanese volunteers after immunization with yellow fever vaccine].

    PubMed

    Taga, Kenichiro; Imura, Shunro; Hayashi, Akihiro; Kamakura, Kazumasa; Hashimoto, Satoru; Takasaki, Tomohiko; Kurane, Ichiro; Uchida, Yukinori

    2002-09-01

    To monitor the development of specific and cross-reactive antibody response in twenty Japanese volunteers after vaccination with live yellow fever vaccine. Serum samples were collected on various days after vaccination and examined for hemagglutination inhibition (HI) antibodies against yellow fever virus (YFV), Japanese encephalitis virus (JEV) and dengue virus (DV), neutralizing antibodies against YFV and JEV, and IgM antibodies against YFV. None of the volunteers had been previously immunized with this vaccine. Fifteen of 20 had pre-vaccinated with JEV 7 to 40 years before. Ten of the 20 had neutralizing antibodies against JEV before immunization. None of the 20 had detectable antibodies against YFV or DV before vaccination. On day 10th after the vaccination, neutralizing antibodies to YFV were detected in 6 of 19 volunteers and IgM antibodies against YFV were detected in 7 of 19. On day 14th, HI, neutralizing, and IgM antibodies against YFV were detected in all the tested sera. Neutralizing antibodies against JEV were developed in 2 volunteers and HI antibodies against JEV were increased in 3 of 6 volunteers respectively. On day 29th, cross-reactive HI antibodies for JEV and DV were detected in all the tested sera. The results indicate that YF vaccine induces YFV-specific antibodies in all the tested volunteers and that it also induces HI antibodies cross-reactive for JEV and DV. The YF vaccine has a strong immunogenicity because it is a live vaccine, and induces antibody against YFV predominantly. The international certificate of yellow fever vaccination becomes valid 10 days after vaccination. On day 14th after vaccination, we detected neutralizing antibodies against YFV from all tested volunteers, however, only 6 of 19 volunteers had detectable neutralizing antibody on the 10th day after vaccination. Therefore, the vaccine may not be perfectly effective on day 10th after the vaccination.

  5. Ebola hemorrhagic fever outbreaks: strategies for effective epidemic management, containment and control.

    PubMed

    Matua, Gerald Amandu; Van der Wal, Dirk Mostert; Locsin, Rozzano C

    2015-01-01

    Ebola hemorrhagic fever, caused by the highly virulent RNA virus of the filoviridae family, has become one of the world's most feared pathogens. The virus induces acute fever and death, often associated with hemorrhagic symptoms in up to 90% of infected patients. The known sub-types of the virus are Zaire, Sudan, Taï Forest, Bundibugyo and Reston Ebola viruses. In the past, outbreaks were limited to the East and Central African tropical belt with the exception of Ebola Reston outbreaks that occurred in animal facilities in the Philippines, USA and Italy. The on-going outbreak in West Africa that is causing numerous deaths and severe socio-economic challenges has resulted in widespread anxiety globally. This panic may be attributed to the intense media interest, the rapid spread of the virus to other countries like United States and Spain, and moreover, to the absence of an approved treatment or vaccine. Informed by this widespread fear and anxiety, we analyzed the commonly used strategies to manage and control Ebola outbreaks and proposed new approaches that could improve epidemic management and control during future outbreaks. We based our recommendations on epidemic management practices employed during recent outbreaks in East, Central and West Africa, and synthesis of peer-reviewed publications as well as published "field" information from individuals and organizations recently involved in the management of Ebola epidemics. The current epidemic management approaches are largely "reactive", with containment efforts aimed at halting spread of existing outbreaks. We recommend that for better outcomes, in addition to "reactive" interventions, "pre-emptive" strategies also need to be instituted. We conclude that emphasizing both "reactive" and "pre-emptive" strategies is more likely to lead to better epidemic preparedness and response at individual, community, institutional, and government levels, resulting in timely containment of future Ebola outbreaks. Copyright

  6. ELECTROPHORESIS EXPERIMENTS WITH THE VIRUS AND PROTECTIVE BODIES OF YELLOW FEVER

    PubMed Central

    Frobisher, Martin

    1931-01-01

    1. When suspended in slightly alkaline (pH 7.4 to 7.8) saline dilutions of clear, hemoglobin-free normal monkey serum, the virus of yellow fever from infected monkeys and from infected, but blood-free, mosquitoes, usually acts as if it were possessed of a positive electrical charge. 2. The virus tends to assume a negative charge in fluids having a slightly acid reaction. 3. The isoelectric point of the virus seems to be in the neighborhood of pH 7.0, possibly ranging from pH 7.3 to pH 6.9. 4. Exposure to fluid having a reaction of pH 5.0 for 3 hours appeared to inactivate the virus. 5. In experiments in which the suspending fluid was prepared with normal serum diluted with distilled water and containing a good quantity of partly hemolyzed erythrocytes, the virus tended to migrate to the anode. 6. The protective bodies in yellow fever immune serum appear to carry a negative charge in slightly alkaline saline dilutions of serum. PMID:19869954

  7. NMOSD triggered by yellow fever vaccination - An unusual clinical presentation with segmental painful erythema.

    PubMed

    Schöberl, F; Csanadi, E; Eren, O; Dieterich, M; Kümpfel, T

    2017-01-01

    Neuromyelitis Optica Spectrum Disorder (NMOSD) is an immune-mediated disease of the central nervous system with the presence of aquaporin 4-antibodies (AQP4-abs) in most cases. We describe a patient who developed NMOSD after a yellow fever vaccination. He presented to us with an unusual painful erythema Th7-9 triggered by touch in the respective skin area due to a cervical spinal cord lesion affecting the dorsolateral parts of C6/7. To our knowledge, this is the first case of NMOSD with such a clinical presentation expanding the clinical spectrum of NMOSD. It is important to be aware of that a yellow fever vaccination can trigger NMOSD. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Midzonal lesions in yellow fever: a specific pattern of liver injury caused by direct virus action and in situ inflammatory response.

    PubMed

    Quaresma, Juarez A S; Duarte, Maria I S; Vasconcelos, Pedro F C

    2006-01-01

    Yellow fever is an acute infectious, non-contagious disease characterized by intense vasculopathy and lesions in different organs. In the liver, one of the main targets of the virus, the infection induces a characteristic midzonal injury characterized by hepatocyte necrosis, apoptosis and steatosis. This characteristics pattern of liver injury in yellow fever is also observed in conditions of low-flow hypoxia and other infections such as dengue and Rift Valley fever. There are no reports in the literature explaining the genesis of this peculiar histopathological pattern in yellow fever. Some hypotheses have been proposed to explain the mechanism of this midzonal distribution pattern observed in the liver such as low-flow hypoxia and tropism of the virus toward hepatocytes in this area. These hypotheses are discussed in view of more recent findings regarding the pathogenesis of yellow fever and regarding hepatic physiopathology, and a new hypothesis is proposed: the midzonal necrosis is consequence of action of combined factors mainly the direct cytopathic effect of YFV associated with a potent immune response in which CD4+ and CD8+ lymphocytes and the cytokines, especially TGF-beta, but also TNF-alpha and IFN-gamma play an important role.

  9. Typhoid fever outbreak associated with frozen mamey pulp imported from Guatemala to the western United States, 2010.

    PubMed

    Loharikar, Anagha; Newton, Anna; Rowley, Patricia; Wheeler, Charlotte; Bruno, Tami; Barillas, Haroldo; Pruckler, James; Theobald, Lisa; Lance, Susan; Brown, Jeffrey M; Barzilay, Ezra J; Arvelo, Wences; Mintz, Eric; Fagan, Ryan

    2012-07-01

    Fifty-four outbreaks of domestically acquired typhoid fever were reported between 1960 and 1999. In 2010, the Southern Nevada Health District detected an outbreak of typhoid fever among persons who had not recently travelled abroad. We conducted a case-control study to examine the relationship between illness and exposures. A case was defined as illness with the outbreak strain of Salmonella serotype Typhi, as determined by pulsed-field gel electrophoresis (PFGE), with onset during 2010. Controls were matched by neighborhood, age, and sex. Bivariate and multivariate statistical analyses were completed using logistic regression. Traceback investigation was completed. We identified 12 cases in 3 states with onset from 15 April 2010 to 4 September 2010. The median age of case patients was 18 years (range, 4-48 years), 8 (67%) were female, and 11 (92%) were Hispanic. Nine (82%) were hospitalized; none died. Consumption of frozen mamey pulp in a fruit shake was reported by 6 of 8 case patients (75%) and none of the 33 controls (matched odds ratio, 33.9; 95% confidence interval, 4.9). Traceback investigations implicated 2 brands of frozen mamey pulp from a single manufacturer in Guatemala, which was also implicated in a 1998-1999 outbreak of typhoid fever in Florida. Reporting of individual cases of typhoid fever and subtyping of isolates by PFGE resulted in rapid detection of an outbreak associated with a ready-to-eat frozen food imported from a typhoid-endemic region. Improvements in food manufacturing practices and monitoring will prevent additional outbreaks.

  10. RNA interference inhibits yellow fever virus replication in vitro and in vivo.

    PubMed

    Pacca, Carolina C; Severino, Adriana A; Mondini, Adriano; Rahal, Paula; D'avila, Solange G P; Cordeiro, José Antonio; Nogueira, Mara Correa Lelles; Bronzoni, Roberta V M; Nogueira, Maurício L

    2009-04-01

    RNA interference (RNAi) is a process that is induced by double stranded RNA and involves the degradation of specific sequences of mRNA in the cytoplasm of the eukaryotic cells. It has been used as an antiviral tool against many viruses, including flaviviruses. The genus Flavivirus contains the most important arboviruses in the world, i.e., dengue (DENV) and yellow fever (YFV). In our study, we investigated the in vitro and in vivo effect of RNAi against YFV. Using stable cell lines that expressed RNAi against YFV, the cell lines were able to inhibit as much as 97% of the viral replication. Two constructions (one against NS1 and the other against E region of YFV genome) were able to protect the adult Balb/c mice against YFV challenge. The histopathologic analysis demonstrated an important protection of the central nervous system by RNAi after 10 days of viral challenge. Our data suggests that RNAi is a potential viable therapeutic weapon against yellow fever.

  11. The emergence and outbreak of multidrug-resistant typhoid fever in China.

    PubMed

    Yan, Meiying; Li, Xinlan; Liao, Qiaohong; Li, Fang; Zhang, Jing; Kan, Biao

    2016-06-22

    Typhoid fever remains a severe public health problem in developing countries. The emergence of resistant typhoid, particularly multidrug-resistant typhoid infections, highlights the necessity of monitoring the resistance characteristics of this invasive pathogen. In this study, we report a typhoid fever outbreak caused by multidrug-resistant Salmonella enterica serovar Typhi strains with an ACSSxtT pattern. Resistance genes conferring these phenotypes were harbored by a large conjugative plasmid, which increases the threat of Salmonella Typhi and thus requires close surveillance for dissemination of strains containing such genes.

  12. A large outbreak of typhoid fever associated with a high rate of intestinal perforation in Kasese District, Uganda, 2008-2009.

    PubMed

    Neil, Karen P; Sodha, Samir V; Lukwago, Luswa; O-Tipo, Shikanga; Mikoleit, Matthew; Simington, Sherricka D; Mukobi, Peter; Balinandi, Stephen; Majalija, Samuel; Ayers, Joseph; Kagirita, Atek; Wefula, Edward; Asiimwe, Frank; Kweyamba, Vianney; Talkington, Deborah; Shieh, Wun-Ju; Adem, Patricia; Batten, Brigid C; Zaki, Sherif R; Mintz, Eric

    2012-04-01

    Salmonella enterica serovar Typhi (Salmonella Typhi) causes an estimated 22 million typhoid fever cases and 216 000 deaths annually worldwide. In Africa, the lack of laboratory diagnostic capacity limits the ability to recognize endemic typhoid fever and to detect outbreaks. We report a large laboratory-confirmed outbreak of typhoid fever in Uganda with a high proportion of intestinal perforations (IPs). A suspected case of typhoid fever was defined as fever and abdominal pain in a person with either vomiting, diarrhea, constipation, headache, weakness, arthralgia, poor response to antimalarial medications, or IP. From March 4, 2009 to April 17, 2009, specimens for blood and stool cultures and serology were collected from suspected cases. Antimicrobial susceptibility testing and pulsed-field gel electrophoresis (PFGE) were performed on Salmonella Typhi isolates. Surgical specimens from patients with IP were examined. A community survey was conducted to characterize the extent of the outbreak. From December 27, 2007 to July 30, 2009, 577 cases, 289 hospitalizations, 249 IPs, and 47 deaths from typhoid fever occurred; Salmonella Typhi was isolated from 27 (33%) of 81 patients. Isolates demonstrated multiple PFGE patterns and uniform susceptibility to ciprofloxacin. Surgical specimens from 30 patients were consistent with typhoid fever. Estimated typhoid fever incidence in the community survey was 8092 cases per 100 000 persons. This typhoid fever outbreak was detected because of an elevated number of IPs. Underreporting of milder illnesses and delayed and inadequate antimicrobial treatment contributed to the high perforation rate. Enhancing laboratory capacity for detection is critical to improving typhoid fever control.

  13. Outbreak of scarlet fever associated with emm12 type group A Streptococcus in 2011 in Shanghai, China.

    PubMed

    Chen, Mingliang; Yao, Weilei; Wang, Xiaohong; Li, Yuefang; Chen, Min; Wang, Gangyi; Zhang, Xi; Pan, Hao; Hu, Jiayu; Zeng, Mei

    2012-09-01

    An unprecedented, large outbreak of childhood scarlet fever occurred in Shanghai between April and July 2011. Investigation of the epidemiology could enhance our understanding of the factors related to the outbreak. We retrospectively analyzed the demographic and seasonal characteristics of children with scarlet fever and the outcome. During the peak month of the 2011 outbreak, 45 GAS isolates recovered from pediatric patients and 13 (43.3%) GAS isolates recovered from 30 asymptomatic student contacts were characterized by emm typing, superantigen profiles, pulsed-field gel electrophoresis genotypes, mutilocus sequence typing and antimicrobial susceptibility. The 2011 outbreak of scarlet fever started in April and peaked in May and June. Boys outnumbered girls (65.1% versus 34.9%). Preschool and primary school children accounted for 96% of cases. No severe outcome was found. emm1, emm12 and emm75 were identified among 58 GAS isolates, and 53 (91.4%) isolates belonged to emm12, st36. Ten pulsed-field gel electrophoresis genotypes were identified among emm12 GAS isolates, 43 (81.1%) shared SPYS16.001 genotype and the remaining 7 genotypes detected were related to SPYS16.001 closely or possibly. No streptococcal pyrogenic exotoxin A and streptococcal pyrogenic exotoxin M were detected in 58 isolates. All emm12 GAS isolates were resistant to azithromycin and clindamycin. emm12 GAS strain caused the large 2011 outbreak of scarlet fever in Shanghai. Antibiotic resistance to macrolides and clindamycin in GAS is prevalent in Shanghai.

  14. The emergence and outbreak of multidrug-resistant typhoid fever in China

    PubMed Central

    Yan, Meiying; Li, Xinlan; Liao, Qiaohong; Li, Fang; Zhang, Jing; Kan, Biao

    2016-01-01

    Typhoid fever remains a severe public health problem in developing countries. The emergence of resistant typhoid, particularly multidrug-resistant typhoid infections, highlights the necessity of monitoring the resistance characteristics of this invasive pathogen. In this study, we report a typhoid fever outbreak caused by multidrug-resistant Salmonella enterica serovar Typhi strains with an ACSSxtT pattern. Resistance genes conferring these phenotypes were harbored by a large conjugative plasmid, which increases the threat of Salmonella Typhi and thus requires close surveillance for dissemination of strains containing such genes. PMID:27329848

  15. Adverse events following yellow fever immunization: Report and analysis of 67 neurological cases in Brazil.

    PubMed

    Martins, Reinaldo de Menezes; Pavão, Ana Luiza Braz; de Oliveira, Patrícia Mouta Nunes; dos Santos, Paulo Roberto Gomes; Carvalho, Sandra Maria D; Mohrdieck, Renate; Fernandes, Alexandre Ribeiro; Sato, Helena Keico; de Figueiredo, Patricia Mandali; von Doellinger, Vanessa Dos Reis; Leal, Maria da Luz Fernandes; Homma, Akira; Maia, Maria de Lourdes S

    2014-11-20

    Neurological adverse events following administration of the 17DD substrain of yellow fever vaccine (YEL-AND) in the Brazilian population are described and analyzed. Based on information obtained from the National Immunization Program through passive surveillance or intensified passive surveillance, from 2007 to 2012, descriptive analysis, national and regional rates of YFV associated neurotropic, neurological autoimmune disease, and reporting rate ratios with their respective 95% confidence intervals were calculated for first time vaccinees stratified on age and year. Sixty-seven neurological cases were found, with the highest rate of neurological adverse events in the age group from 5 to 9 years (2.66 per 100,000 vaccine doses in Rio Grande do Sul state, and 0.83 per 100,000 doses in national analysis). Two cases had a combination of neurotropic and autoimmune features. This is the largest sample of YEL-AND already analyzed. Rates are similar to other recent studies, but on this study the age group from 5 to 9 years of age had the highest risk. As neurological adverse events have in general a good prognosis, they should not contraindicate the use of yellow fever vaccine in face of risk of infection by yellow fever virus. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. First reported chikungunya fever outbreak in the republic of Congo, 2011.

    PubMed

    Moyen, Nanikaly; Thiberville, Simon-Djamel; Pastorino, Boris; Nougairede, Antoine; Thirion, Laurence; Mombouli, Jean-Vivien; Dimi, Yannick; Leparc-Goffart, Isabelle; Capobianchi, Maria Rosaria; Lepfoundzou, Amelia Dzia; de Lamballerie, Xavier

    2014-01-01

    Chikungunya is an Aedes -borne disease characterised by febrile arthralgia and responsible for massive outbreaks. We present a prospective clinical cohort study and a retrospective serological study relating to a CHIK outbreak, in the Republic of Congo in 2011. We analysed 317 suspected cases, of which 308 (97.2%) lived in the city of Brazzaville (66.6% in the South area). Amongst them, 37 (11.7%) were CHIKV+ve patients (i.e., biologically confirmed by a real-time RT-PCR assay), of whom 36 (97.3%) had fever, 22 (66.7%) myalgia and 32 (86.5%) arthralgia. All tested negative for dengue. The distribution of incident cases within Brazzaville districts was compared with CHIKV seroprevalence before the outbreak (34.4% in 517 blood donors), providing evidence for previous circulation of CHIKV. We applied a CHIK clinical score to 126 patients recruited within the two first day of illness (including 28 CHIKV+ves (22.2%)) with sensitivity (78.6%) and specificity (72.4%) values comparing with those of the referent study in Reunion Island. The negative predictive value was high (92%), but the positive predictive value (45%) indicate poor potential contribution to medical practice to identify CHIKV+ve patients in low prevalence outbreaks. However, the score allowed a slightly more accurate follow-up of the evolution of the outbreak than the criterion "fever+arthralgia". The complete sequencing of a Congolase isolate (Brazza_MRS1) demonstrated belonging to the East/Central/South African lineage and was further used for producing a robust genome-scale CHIKV phylogenetic analysis. We describe the first Chikungunya outbreak declared in the Republic of Congo. The seroprevalence study conducted amongst blood donors before outbreak provided evidence for previous CHIKV circulation. We suggest that a more systematic survey of the entomological situation and of arbovirus circulation is necessary in Central Africa for better understanding the environmental, microbiological and

  17. First Reported Chikungunya Fever Outbreak in the Republic of Congo, 2011

    PubMed Central

    Pastorino, Boris; Nougairede, Antoine; Thirion, Laurence; Mombouli, Jean-Vivien; Dimi, Yannick; Leparc-Goffart, Isabelle; Capobianchi, Maria Rosaria; Lepfoundzou, Amelia Dzia; de Lamballerie, Xavier

    2014-01-01

    Background Chikungunya is an Aedes -borne disease characterised by febrile arthralgia and responsible for massive outbreaks. We present a prospective clinical cohort study and a retrospective serological study relating to a CHIK outbreak, in the Republic of Congo in 2011. Methodology and Findings We analysed 317 suspected cases, of which 308 (97.2%) lived in the city of Brazzaville (66.6% in the South area). Amongst them, 37 (11.7%) were CHIKV+ve patients (i.e., biologically confirmed by a real-time RT-PCR assay), of whom 36 (97.3%) had fever, 22 (66.7%) myalgia and 32 (86.5%) arthralgia. All tested negative for dengue. The distribution of incident cases within Brazzaville districts was compared with CHIKV seroprevalence before the outbreak (34.4% in 517 blood donors), providing evidence for previous circulation of CHIKV. We applied a CHIK clinical score to 126 patients recruited within the two first day of illness (including 28 CHIKV+ves (22.2%)) with sensitivity (78.6%) and specificity (72.4%) values comparing with those of the referent study in Reunion Island. The negative predictive value was high (92%), but the positive predictive value (45%) indicate poor potential contribution to medical practice to identify CHIKV+ve patients in low prevalence outbreaks. However, the score allowed a slightly more accurate follow-up of the evolution of the outbreak than the criterion "fever+arthralgia". The complete sequencing of a Congolase isolate (Brazza_MRS1) demonstrated belonging to the East/Central/South African lineage and was further used for producing a robust genome-scale CHIKV phylogenetic analysis. Conclusions/Significance We describe the first Chikungunya outbreak declared in the Republic of Congo. The seroprevalence study conducted amongst blood donors before outbreak provided evidence for previous CHIKV circulation. We suggest that a more systematic survey of the entomological situation and of arbovirus circulation is necessary in Central Africa for better

  18. One Health approach to controlling a Q fever outbreak on an Australian goat farm.

    PubMed

    Bond, K A; Vincent, G; Wilks, C R; Franklin, L; Sutton, B; Stenos, J; Cowan, R; Lim, K; Athan, E; Harris, O; Macfarlane-Berry, L; Segal, Y; Firestone, S M

    2016-04-01

    A recent outbreak of Q fever was linked to an intensive goat and sheep dairy farm in Victoria, Australia, 2012-2014. Seventeen employees and one family member were confirmed with Q fever over a 28-month period, including two culture-positive cases. The outbreak investigation and management involved a One Health approach with representation from human, animal, environmental and public health. Seroprevalence in non-pregnant milking goats was 15% [95% confidence interval (CI) 7-27]; active infection was confirmed by positive quantitative PCR on several animal specimens. Genotyping of Coxiella burnetii DNA obtained from goat and human specimens was identical by two typing methods. A number of farming practices probably contributed to the outbreak, with similar precipitating factors to the Netherlands outbreak, 2007-2012. Compared to workers in a high-efficiency particulate arrestance (HEPA) filtered factory, administrative staff in an unfiltered adjoining office and those regularly handling goats and kids had 5·49 (95% CI 1·29-23·4) and 5·65 (95% CI 1·09-29·3) times the risk of infection, respectively; suggesting factory workers were protected from windborne spread of organisms. Reduction in the incidence of human cases was achieved through an intensive human vaccination programme plus environmental and biosecurity interventions. Subsequent non-occupational acquisition of Q fever in the spouse of an employee, indicates that infection remains endemic in the goat herd, and remains a challenge to manage without source control.

  19. High Prevalence and Diversity of Hepatitis Viruses in Suspected Cases of Yellow Fever in the Democratic Republic of Congo

    PubMed Central

    Le Gal, Frédéric; Ngwaka-Matsung, Nadine; Ahuka-Mundeke, Steve; Onanga, Richard; Pukuta-Simbu, Elisabeth; Gerber, Athenaïs; Abbate, Jessica L.; Mwamba, Dieudonné; Berthet, Nicolas; Leroy, Eric Maurice; Muyembe-Tamfum, Jean-Jacques

    2017-01-01

    ABSTRACT The majority of patients with acute febrile jaundice (>95%) identified through a yellow fever surveillance program in the Democratic Republic of Congo (DRC) test negative for antibodies against yellow fever virus. However, no etiological investigation has ever been carried out on these patients. Here, we tested for hepatitis A (HAV), hepatitis B (HBV), hepatitis C (HCV), hepatitis D (HDV), and hepatitis E (HEV) viruses, all of which can cause acute febrile jaundice, in patients included in the yellow fever surveillance program in the DRC. On a total of 498 serum samples collected from suspected cases of yellow fever from January 2003 to January 2012, enzyme-linked immunosorbent assay (ELISA) techniques were used to screen for antibodies against HAV (IgM) and HEV (IgM) and for antigens and antibodies against HBV (HBsAg and anti-hepatitis B core protein [HBc] IgM, respectively), HCV, and HDV. Viral loads and genotypes were determined for HBV and HVD. Viral hepatitis serological markers were diagnosed in 218 (43.7%) patients. The seroprevalences were 16.7% for HAV, 24.6% for HBV, 2.3% for HCV, and 10.4% for HEV, and 26.1% of HBV-positive patients were also infected with HDV. Median viral loads were 4.19 × 105 IU/ml for HBV (range, 769 to 9.82 × 109 IU/ml) and 1.4 × 106 IU/ml for HDV (range, 3.1 × 102 to 2.9 × 108 IU/ml). Genotypes A, E, and D of HBV and genotype 1 of HDV were detected. These high hepatitis prevalence rates highlight the necessity to include screening for hepatitis viruses in the yellow fever surveillance program in the DRC. PMID:28202798

  20. High Prevalence and Diversity of Hepatitis Viruses in Suspected Cases of Yellow Fever in the Democratic Republic of Congo.

    PubMed

    Makiala-Mandanda, Sheila; Le Gal, Frédéric; Ngwaka-Matsung, Nadine; Ahuka-Mundeke, Steve; Onanga, Richard; Bivigou-Mboumba, Berthold; Pukuta-Simbu, Elisabeth; Gerber, Athenaïs; Abbate, Jessica L; Mwamba, Dieudonné; Berthet, Nicolas; Leroy, Eric Maurice; Muyembe-Tamfum, Jean-Jacques; Becquart, Pierre

    2017-05-01

    The majority of patients with acute febrile jaundice (>95%) identified through a yellow fever surveillance program in the Democratic Republic of Congo (DRC) test negative for antibodies against yellow fever virus. However, no etiological investigation has ever been carried out on these patients. Here, we tested for hepatitis A (HAV), hepatitis B (HBV), hepatitis C (HCV), hepatitis D (HDV), and hepatitis E (HEV) viruses, all of which can cause acute febrile jaundice, in patients included in the yellow fever surveillance program in the DRC. On a total of 498 serum samples collected from suspected cases of yellow fever from January 2003 to January 2012, enzyme-linked immunosorbent assay (ELISA) techniques were used to screen for antibodies against HAV (IgM) and HEV (IgM) and for antigens and antibodies against HBV (HBsAg and anti-hepatitis B core protein [HBc] IgM, respectively), HCV, and HDV. Viral loads and genotypes were determined for HBV and HVD. Viral hepatitis serological markers were diagnosed in 218 (43.7%) patients. The seroprevalences were 16.7% for HAV, 24.6% for HBV, 2.3% for HCV, and 10.4% for HEV, and 26.1% of HBV-positive patients were also infected with HDV. Median viral loads were 4.19 × 10 5 IU/ml for HBV (range, 769 to 9.82 × 10 9 IU/ml) and 1.4 × 10 6 IU/ml for HDV (range, 3.1 × 10 2 to 2.9 × 10 8 IU/ml). Genotypes A, E, and D of HBV and genotype 1 of HDV were detected. These high hepatitis prevalence rates highlight the necessity to include screening for hepatitis viruses in the yellow fever surveillance program in the DRC. Copyright © 2017 Makiala-Mandanda et al.

  1. Human genetic variation and yellow fever mortality during 19th century U.S. epidemics.

    PubMed

    Blake, Lauren E; Garcia-Blanco, Mariano A

    2014-06-03

    We calculated the incidence, mortality, and case fatality rates for Caucasians and non-Caucasians during 19th century yellow fever (YF) epidemics in the United States and determined statistical significance for differences in the rates in different populations. We evaluated nongenetic host factors, including socioeconomic, environmental, cultural, demographic, and acquired immunity status that could have influenced these differences. While differences in incidence rates were not significant between Caucasians and non-Caucasians, differences in mortality and case fatality rates were statistically significant for all epidemics tested (P < 0.01). Caucasians diagnosed with YF were 6.8 times more likely to succumb than non-Caucasians with the disease. No other major causes of death during the 19th century demonstrated a similar mortality skew toward Caucasians. Nongenetic host factors were examined and could not explain these large differences. We propose that the remarkably lower case mortality rates for individuals of non-Caucasian ancestry is the result of human genetic variation in loci encoding innate immune mediators. Different degrees of severity of yellow fever have been observed across diverse populations, but this study is the first to demonstrate a statistically significant association between ancestry and the outcome of yellow fever (YF). With the global burden of mosquito-borne flaviviral infections, such as YF and dengue, on the rise, identifying and characterizing host factors could prove pivotal in the prevention of epidemics and the development of effective treatments. Copyright © 2014 Blake and Garcia-Blanco.

  2. The safety of yellow fever vaccine 17D or 17DD in children, pregnant women, HIV+ individuals, and older persons: systematic review.

    PubMed

    Thomas, Roger E; Lorenzetti, Diane L; Spragins, Wendy; Jackson, Dave; Williamson, Tyler

    2012-02-01

    Yellow fever vaccine provides long-lasting immunity. Rare serious adverse events after vaccination include neurologic or viscerotropic syndromes or anaphylaxis. We conducted a systematic review of adverse events associated with yellow fever vaccination in vulnerable populations. Nine electronic bibliographic databases and reference lists of included articles were searched. Electronic databases identified 2,415 abstracts for review, and 32 abstracts were included in this review. We identified nine studies of adverse events in infants and children, eight studies of adverse events in pregnant women, nine studies of adverse events in human immunodeficiency virus-positive patients, five studies of adverse events in persons 60 years and older, and one study of adverse events in individuals taking immunosuppressive medications. Two case studies of maternal-neonate transmission resulted in serious adverse events, and the five passive surveillance databases identified very small numbers of cases of yellow fever vaccine-associated viscerotropic disease, yellow fever vaccine-associated neurotropic disease, and anaphylaxis in persons ≥ 60 years. No other serious adverse events were identified in the other studies of vulnerable groups.

  3. A Mixed Outbreak of Epidemic Typhus Fever and Trench Fever in a Youth Rehabilitation Center: Risk Factors for Illness from a Case-Control Study, Rwanda, 2012

    PubMed Central

    Umulisa, Irenee; Omolo, Jared; Muldoon, Katherine A.; Condo, Jeanine; Habiyaremye, Francois; Uwimana, Jean Marie; Muhimpundu, Marie Aimee; Galgalo, Tura; Rwunganira, Samuel; Dahourou, Anicet G.; Tongren, Eric; Koama, Jean Baptiste; McQuiston, Jennifer; Raghunathan, Pratima L.; Massung, Robert; Gatei, Wangeci; Boer, Kimberly; Nyatanyi, Thierry; Mills, Edward J.; Binagwaho, Agnes

    2016-01-01

    In August 2012, laboratory tests confirmed a mixed outbreak of epidemic typhus fever and trench fever in a male youth rehabilitation center in western Rwanda. Seventy-six suspected cases and 118 controls were enrolled into an unmatched case-control study to identify risk factors for symptomatic illness during the outbreak. A suspected case was fever or history of fever, from April 2012, in a resident of the rehabilitation center. In total, 199 suspected cases from a population of 1,910 male youth (attack rate = 10.4%) with seven deaths (case fatality rate = 3.5%) were reported. After multivariate analysis, history of seeing lice in clothing (adjusted odds ratio [aOR] = 2.6, 95% confidence interval [CI] = 1.1–5.8), delayed (≥ 2 days) washing of clothing (aOR = 4.0, 95% CI = 1.6–9.6), and delayed (≥ 1 month) washing of beddings (aOR = 4.6, 95% CI = 2.0–11) were associated with illness, whereas having stayed in the rehabilitation camp for ≥ 6 months was protective (aOR = 0.20, 95% CI = 0.10–0.40). Stronger surveillance and improvements in hygiene could prevent future outbreaks. PMID:27352876

  4. Viscerotropic and neurotropic disease following vaccination with the 17D yellow fever vaccine, ARILVAX.

    PubMed

    Kitchener, Scott

    2004-06-02

    Yellow fever vaccine associated viscerotropic (YFV-AVD) and neurotropic (YFV-AND) diseases have been recently identified in various countries. Previously post-vaccination multiple organ system failure was recognised as a rare serious adverse event of yellow fever vaccination and 21 cases of post-vaccinal (YFV) encephalitis had been recorded. Incidence data is not available. On investigation of vaccine surveillance reports from Europe following distribution of more than 3 million doses of ARILVAX trade mark, four cases each of YFV-AVD and YFV-AND were found (each 1.3 cases per million doses distributed) for the period 1991 to 2003. The incidence for each is higher after 1996 (2.5 cases per million doses distributed). The incidence of these adverse events appears to be very low with ARILVAX trade mark. Similar incidence data is required from other countries for comparison.

  5. An outbreak of gastroenteritis and fever due to Listeria monocytogenes in milk.

    PubMed

    Dalton, C B; Austin, C C; Sobel, J; Hayes, P S; Bibb, W F; Graves, L M; Swaminathan, B; Proctor, M E; Griffin, P M

    1997-01-09

    After an outbreak of gastroenteritis and fever among persons who attended a picnic in Illinois, chocolate milk served at the picnic was found to be contaminated with Listeria monocytogenes. In investigating this outbreak, we interviewed the people who attended the picnic about what they ate and their symptoms. Surveillance for invasive listeriosis was initiated in the states that receive milk from the implicated dairy. Stool and milk samples were cultured for L. monocytogenes. Serum samples were tested for IgG antibody to listeriolysin O. Forty-five persons had symptoms that met the case definition for illness due to L. monocytogenes, and cultures of stool from 11 persons yielded the organism. Illness in the week after the picnic was associated with the consumption of chocolate milk. The most common symptoms were diarrhea (present in 79 percent of the cases) and fever (72 percent). Four persons were hospitalized. The median incubation period for infection was 20 hours (range, 9 to 32), and persons who became ill had elevated levels of antibody to listeriolysin O. Isolates from stool specimens from patients who became ill after the picnic, from sterile sites in three additional patients identified by surveillance, from the implicated chocolate milk, and from a tank drain at the dairy were all serotype 1/2b and were indistinguishable on multilocus enzyme electrophoresis, ribotyping, and DNA macrorestriction analysis. L. monocytogenes is a cause of gastroenteritis with fever, and sporadic cases of invasive listeriosis may be due to unrecognized outbreaks caused by contaminated food.

  6. Yellow fever and Max Theiler: the only Nobel Prize for a virus vaccine

    PubMed Central

    Norrby, Erling

    2007-01-01

    In 1951, Max Theiler of the Rockefeller Foundation received the Nobel Prize in Physiology or Medicine for his discovery of an effective vaccine against yellow fever—a discovery first reported in the JEM 70 years ago. This was the first, and so far the only, Nobel Prize given for the development of a virus vaccine. Recently released Nobel archives now reveal how the advances in the yellow fever vaccine field were evaluated more than 50 years ago, and how this led to a prize for Max Theiler. PMID:18039952

  7. Blood Meal Analysis of Mosquitoes Involved in a Rift Valley fever Outbreak

    USDA-ARS?s Scientific Manuscript database

    Background: Rift Valley fever (RVF) is a zoonosis of domestic ruminants in Africa. Bloodfed mosquitoes collected during the 2006-2007 RVF outbreak in Kenya were analyzed to determine the virus infection status and animal source of the bloodmeals. Bloodmeals from individual mosquito abdomens were sc...

  8. Epidemiological investigation of an outbreak of typhoid fever in Jorhat town of Assam, India.

    PubMed

    Roy, Jashbeer Singh; Saikia, Lahari; Medhi, Mithu; Tassa, Dipak

    2016-10-01

    Typhoid fever is a global health problem and is also endemic in India. An outbreak of fever occurred in January 2014 in Jorhat Town in Assam, India. Here we report the results of an investigation done to find out the aetiology and source of the outbreak. The affected areas were visited on January 23, 2014 by a team of Jorhat district Integrated Disease Surveillance Project personnel. A total of 13 blood samples from patients with fever as first symptom and six water samples were collected from the affected areas. The blood samples were cultured and isolates were identified using standard biochemical tests. Isolates were also tested for antimicrobial sensitivity. Widal test was performed on 10 of the 13 blood samples collected. Sanitary survey was carried out to find any leakage in the water supply and also the sewage system of the Jorhat town. Blood culture yielded Salmonella enterica serovar Typhi in six (46.15%) patients whereas Widal test was positive in 10 (76.9%) of 13 patients. Water culture showed presumptive coliform count of >180/100 ml in two out of the six samples tested. Salmonella Typhi was also isolated from water culture of these two samples. Sanitary survey carried out in the affected places showed that the water supply pipes of urban water supply were in close proximity to the sewage drainage system and there were few leakages. The outbreak occurred due to S. Typhi contaminating the water supply. Sanitation and immunization are the two most important components to be stressed to prevent such outbreaks.

  9. Yellow fever vaccine: recommendations of the Advisory Committee on Immunization Practices (ACIP).

    PubMed

    Staples, J Erin; Gershman, Mark; Fischer, Marc

    2010-07-30

    This report updates CDC's recommendations for using yellow fever (YF) vaccine (CDC. Yellow fever vaccine: recommendations of the Advisory Committee on Immunizations Practices: MMWR 2002;51[No. RR-17]). Since the previous YF vaccine recommendations were published in 2002, new or additional information has become available on the epidemiology of YF, safety profile of the vaccine, and health regulations related to the vaccine. This report summarizes the current epidemiology of YF, describes immunogenicity and safety data for the YF vaccine, and provides recommendations for the use of YF vaccine among travelers and laboratory workers. YF is a vectorborne disease resulting from the transmission of yellow fever virus (YFV) to a human from the bite of an infected mosquito. It is endemic to sub-Saharan Africa and tropical South America and is estimated to cause 200,000 cases of clinical disease and 30,000 deaths annually. Infection in humans is capable of producing hemorrhagic fever and is fatal in 20%-50% of persons with severe disease. Because no treatment exists for YF disease, prevention is critical to lower disease risk and mortality. A traveler's risk for acquiring YFV is determined by multiple factors, including immunization status, location of travel, season, duration of exposure, occupational and recreational activities while traveling, and local rate of virus transmission at the time of travel. All travelers to countries in which YF is endemic should be advised of the risks for contracting the disease and available methods to prevent it, including use of personal protective measures and receipt of vaccine. Administration of YF vaccine is recommended for persons aged >or=9 months who are traveling to or living in areas of South America and Africa in which a risk exists for YFV transmission. Because serious adverse events can occur following YF vaccine administration, health-care providers should vaccinate only persons who are at risk for exposure to YFV or who

  10. Single shot of 17D vaccine may not confer life-long protection against yellow fever.

    PubMed

    Vasconcelos, Pedro Fc

    2018-02-01

    The yellow fever (YF) vaccine has been used since the 1930s to prevent YF, which is a severe infectious disease caused by the yellow fever virus (YFV), and mainly transmitted by Culicidae mosquitoes from the genera Aedes and Haemagogus . Until 2013, the World Health Organization (WHO) recommended the administration of a vaccine dose every ten years. A new recommendation of a single vaccine dose to confer life-long protection against YFV infection has since been established. Recent evidence published elsewhere suggests that at least a second dose is needed to fully protect against YF disease. Here, we discuss the feasibility of administering multiple doses, the necessity for a new and modern vaccine, and recommend that the WHO conveys a meeting to discuss YFV vaccination strategies for people living in or travelling to endemic areas.

  11. Large outbreak of Legionnaires' disease and Pontiac fever at a military base.

    PubMed

    Ambrose, J; Hampton, L M; Fleming-Dutra, K E; Marten, C; McClusky, C; Perry, C; Clemmons, N A; McCormic, Z; Peik, S; Mancuso, J; Brown, E; Kozak, N; Travis, T; Lucas, C; Fields, B; Hicks, L; Cersovsky, S B

    2014-11-01

    We investigated a mixed outbreak of Legionnaires' disease (LD) and Pontiac fever (PF) at a military base to identify the outbreak's environmental source as well as known legionellosis risk factors. Base workers with possible legionellosis were interviewed and, if consenting, underwent testing for legionellosis. A retrospective cohort study collected information on occupants of the buildings closest to the outbreak source. We identified 29 confirmed and probable LD and 38 PF cases. All cases were exposed to airborne pathogens from a cooling tower. Occupants of the building closest to the cooling tower were 6·9 [95% confidence interval (CI) 2·2-22·0] and 5·5 (95% CI 2·1-14·5) times more likely to develop LD and PF, respectively, than occupants of the next closest building. Thorough preventive measures and aggressive responses to outbreaks, including searching for PF cases in mixed legionellosis outbreaks, are essential for legionellosis control.

  12. WHO position on the use of fractional doses - June 2017, addendum to vaccines and vaccination against yellow fever WHO: Position paper - June 2013.

    PubMed

    World Health Organization

    2017-10-13

    This article presents the World Health Organization's (WHO) recommendations on the use of fractional doses of yellow fever vaccines excerpted from the "Yellow fever vaccine: WHO position on the use of fractional doses - June 2017, Addendum to Vaccines and vaccination against yellow fever WHO: Position Paper - June 2013″, published in the Weekly Epidemiological Record [1,2]. This addendum to the 2013 position paper pertains specifically to use of fractional dose YF (fYF) vaccination (fractional dose yellow fever vaccination refers to administration of a reduced volume of vaccine dose, which has been reconstituted as usual per manufacturer recommendations) in the context of YF vaccine supply shortages beyond the capacity of the global stockpile. The current WHO position on the use of yellow fever (YF) vaccine is set out in the 2013 WHO position paper on vaccines and vaccination against YF and those recommendations are unchanged. Footnotes to this paper provide a number of core references including references to grading tables that assess the quality of the scientific evidence, and to the evidence-to-recommendation table. In accordance with its mandate to provide guidance to Member States on health policy matters, WHO issues a series of regularly updated position papers on vaccines and combinations of vaccines against diseases that have an international public health impact. These papers are concerned primarily with the use of vaccines in large-scale immunization programmes; they summarize essential background information on diseases and vaccines, and conclude with WHO's current position on the use of vaccines in the global context. Recommendations on the use of Yellow Fever vaccines were discussed by SAGE in October 2016; evidence presented at these meetings can be accessed at: www.who.int/immunization/sage/meetings/2016/October/presentations_background_docs/en/. Copyright © 2017. Published by Elsevier Ltd.

  13. Yellow fever from Angola and Congo: a storm gathers.

    PubMed

    Ahmed, Qanta A; Memish, Ziad A

    2017-04-01

    In common with Zika, Chikungunya and Dengue, Yellow Fever (YF) is an arthropod-borne flavivirus. It is transmitted between humans and from monkeys by mosquitoes of the Aedes aegypti (its principal vector), haemogogus and albopictus varieties. Three cycles of transmission may occur: urban; sylvatic; and intermediate. Recently, sub-Saharan Africa has seen the resurgence of this neglected disease. The current YF outbreak in Angola began in December 2015 in the capital Luanda and by October 2016 there had been > 4300 suspected cases, with 376 deaths (case fatality rate = 8.8%). A total of 884 were laboratory confirmed but it is likely that case numbers may be seriously underestimated. YF has subsequently quickly spread to neighbouring Congo and further afield to Kenya and also China, this being of grave concern as this was a first introduction of YF to Asia. YF has recently hit Brazil, with 555 suspected cases and 107 deaths reported by the end of January 2017. Extremely rapid unplanned urban migration in Africa by non-immune rural populations to already densely populated cities, where high densities of mosquitoes co-exist with city dwellers in makeshift flimsy accommodation, poses a ready recipe for an epidemic of massive proportion. In such conditions, with enormously strained public services existing among the most needy and vulnerable populations, mosquito control programmes are nearly impossible. YF in Congo is a tempest barely restrained. However, it is one that can be controlled by focused and committed international collaboration, by intense and united political will and by the marriage of old and trusted techniques: a vaccine almost a century old and some of the most modern technologies available to man.

  14. Broadening the horizons for yellow fever: new uses for an old vaccine.

    PubMed

    Van Epps, Heather L

    2005-01-17

    The vaccine against yellow fever is one of the safest and most effective ever developed. With an outstanding record in humans, has this live attenuated vaccine been overlooked as a promising vector for the development of vaccines against pathogens outside its own genus? Recent studies, including a report by Tao et al. on page 201 of this issue, have sparked renewed interest.

  15. Ocular manifestations of emerging arboviruses: Dengue fever, Chikungunya, Zika virus, West Nile virus, and yellow fever.

    PubMed

    Merle, H; Donnio, A; Jean-Charles, A; Guyomarch, J; Hage, R; Najioullah, F; Césaire, R; Cabié, A

    2018-06-18

    Arboviruses are viral diseases transmitted by mosquitoes and tick bites. They are a major cause of morbidity and sometimes mortality. Their expansion is constant and due in part to climate change and globalization. Mostly found in tropical regions, arboviruses are sometimes the source of epidemics in Europe. Recently, the Chikungunya virus and the Zika virus were responsible for very large epidemics impacting populations that had never been in contact with those viruses. There are currently no effective antiviral treatments or vaccines. Ocular manifestations due to those infections are thus more frequent and increasingly better described. They are sometimes, as with Zika, complicated by a congenital ocular syndrome. The goal of this review is to describe the ophthalmological manifestations of Dengue fever, Chikungunya virus, Zika virus, West Nile virus, and yellow fever. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  16. A Mixed Outbreak of Epidemic Typhus Fever and Trench Fever in a Youth Rehabilitation Center: Risk Factors for Illness from a Case-Control Study, Rwanda, 2012.

    PubMed

    Umulisa, Irenee; Omolo, Jared; Muldoon, Katherine A; Condo, Jeanine; Habiyaremye, Francois; Uwimana, Jean Marie; Muhimpundu, Marie Aimee; Galgalo, Tura; Rwunganira, Samuel; Dahourou, Anicet G; Tongren, Eric; Koama, Jean Baptiste; McQuiston, Jennifer; Raghunathan, Pratima L; Massung, Robert; Gatei, Wangeci; Boer, Kimberly; Nyatanyi, Thierry; Mills, Edward J; Binagwaho, Agnes

    2016-08-03

    In August 2012, laboratory tests confirmed a mixed outbreak of epidemic typhus fever and trench fever in a male youth rehabilitation center in western Rwanda. Seventy-six suspected cases and 118 controls were enrolled into an unmatched case-control study to identify risk factors for symptomatic illness during the outbreak. A suspected case was fever or history of fever, from April 2012, in a resident of the rehabilitation center. In total, 199 suspected cases from a population of 1,910 male youth (attack rate = 10.4%) with seven deaths (case fatality rate = 3.5%) were reported. After multivariate analysis, history of seeing lice in clothing (adjusted odds ratio [aOR] = 2.6, 95% confidence interval [CI] = 1.1-5.8), delayed (≥ 2 days) washing of clothing (aOR = 4.0, 95% CI = 1.6-9.6), and delayed (≥ 1 month) washing of beddings (aOR = 4.6, 95% CI = 2.0-11) were associated with illness, whereas having stayed in the rehabilitation camp for ≥ 6 months was protective (aOR = 0.20, 95% CI = 0.10-0.40). Stronger surveillance and improvements in hygiene could prevent future outbreaks. © The American Society of Tropical Medicine and Hygiene.

  17. Yellow Fever Remains a Potential Threat to Public Health.

    PubMed

    Vasconcelos, Pedro F C; Monath, Thomas P

    2016-08-01

    Yellow fever (YF) remains a serious public health threat in endemic countries. The recent re-emergence in Africa, initiating in Angola and spreading to Democratic Republic of Congo and Uganda, with imported cases in China and Kenya is of concern. There is such a shortage of YF vaccine in the world that the World Health Organization has proposed the use of reduced doses (1/5) during emergencies. In this short communication, we discuss these and other problems including the risk of spread of YF to areas free of YF for decades or never before affected by this arbovirus disease.

  18. A Flow Cytometry-Based Assay for Quantifying Non-Plaque Forming Strains of Yellow Fever Virus

    PubMed Central

    Hammarlund, Erika; Amanna, Ian J.; Dubois, Melissa E.; Barron, Alex; Engelmann, Flora; Messaoudi, Ilhem; Slifka, Mark K.

    2012-01-01

    Primary clinical isolates of yellow fever virus can be difficult to quantitate by standard in vitro methods because they may not form discernable plaques or induce a measurable cytopathic effect (CPE) on cell monolayers. In our hands, the Dakar strain of yellow fever virus (YFV-Dakar) could not be measured by plaque assay (PA), focus-forming assay (FFA), or by measurement of CPE. For these reasons, we developed a YFV-specific monoclonal antibody (3A8.B6) and used it to optimize a highly sensitive flow cytometry-based tissue culture limiting dilution assay (TC-LDA) to measure levels of infectious virus. The TC-LDA was performed by incubating serial dilutions of virus in replicate wells of C6/36 cells and stained intracellularly for virus with MAb 3A8.B6. Using this approach, we could reproducibly quantitate YFV-Dakar in tissue culture supernatants as well as from the serum of viremic rhesus macaques experimentally infected with YFV-Dakar. Moreover, the TC-LDA approach was >10-fold more sensitive than standard plaque assay for quantitating typical plaque-forming strains of YFV including YFV-17D and YFV-FNV (French neurotropic vaccine). Together, these results indicate that the TC-LDA technique is effective for quantitating both plaque-forming and non-plaque-forming strains of yellow fever virus, and this methodology may be readily adapted for the study and quantitation of other non-plaque-forming viruses. PMID:23028428

  19. A flow cytometry-based assay for quantifying non-plaque forming strains of yellow fever virus.

    PubMed

    Hammarlund, Erika; Amanna, Ian J; Dubois, Melissa E; Barron, Alex; Engelmann, Flora; Messaoudi, Ilhem; Slifka, Mark K

    2012-01-01

    Primary clinical isolates of yellow fever virus can be difficult to quantitate by standard in vitro methods because they may not form discernable plaques or induce a measurable cytopathic effect (CPE) on cell monolayers. In our hands, the Dakar strain of yellow fever virus (YFV-Dakar) could not be measured by plaque assay (PA), focus-forming assay (FFA), or by measurement of CPE. For these reasons, we developed a YFV-specific monoclonal antibody (3A8.B6) and used it to optimize a highly sensitive flow cytometry-based tissue culture limiting dilution assay (TC-LDA) to measure levels of infectious virus. The TC-LDA was performed by incubating serial dilutions of virus in replicate wells of C6/36 cells and stained intracellularly for virus with MAb 3A8.B6. Using this approach, we could reproducibly quantitate YFV-Dakar in tissue culture supernatants as well as from the serum of viremic rhesus macaques experimentally infected with YFV-Dakar. Moreover, the TC-LDA approach was >10-fold more sensitive than standard plaque assay for quantitating typical plaque-forming strains of YFV including YFV-17D and YFV-FNV (French neurotropic vaccine). Together, these results indicate that the TC-LDA technique is effective for quantitating both plaque-forming and non-plaque-forming strains of yellow fever virus, and this methodology may be readily adapted for the study and quantitation of other non-plaque-forming viruses.

  20. POSSIBILITY OF HEREDITARY TRANSMISSION OF YELLOW FEVER VIRUS BY AEDES AEGYPTI (LINN.)

    PubMed Central

    Philip, Cornelius B.

    1929-01-01

    Attempts to obtain passage of yellow fever virus from one generation to the next in A. aegypti were unsuccessful. Subcutaneous injections at varying intervals of a saline emulsion of 200 eggs laid by an infective lot of mosquitoes produced no reaction in six normal M. rhesus monkeys. Negative results were also obtained in five biting and two injection experiments with progeny of the same infective lot of mosquitoes in which seven normal monkeys were used. The eggs consisted of batches laid after the first, second and fourth blood-meals of the original lot; the latter feeding occurred 41 days after the initial infecting meal. The imaginal offspring represented rearings following the first, second and fifth blood-meals of the parent lot. The last feeding occurred 54 days after the first. It is concluded that under the conditions of the experiments here reported hereditary transmission of yellow fever by A. aegypti is improbable. Variations in age and in number of blood-meals of parent and offspring mosquitoes had no effect in achieving passage of the virus from one stage of the insect to another. PMID:19869656

  1. Yellow Fever Virus Exhibits Slower Evolutionary Dynamics than Dengue Virus ▿ †

    PubMed Central

    Sall, Amadou A.; Faye, Ousmane; Diallo, Mawlouth; Firth, Cadhla; Kitchen, Andrew; Holmes, Edward C.

    2010-01-01

    Although yellow fever has historically been one of the most important viral infections of humans, relatively little is known about the evolutionary processes that shape its genetic diversity. Similarly, there is limited information on the molecular epidemiology of yellow fever virus (YFV) in Africa even though it most likely first emerged on this continent. Through an analysis of complete E gene sequences, including a newly acquired viral collection from Central and West Africa (Senegal, Cameroon, Central African Republic, Côte d'Ivoire, Mali, and Mauritania), we show that YFV exhibits markedly lower rates of evolutionary change than dengue virus, despite numerous biological similarities between these two viruses. From this observation, along with a lack of clock-like evolutionary behavior in YFV, we suggest that vertical transmission, itself characterized by lower replication rates, may play an important role in the evolution of YFV in its enzootic setting. Despite a reduced rate of nucleotide substitution, phylogenetic patterns and estimates of times to common ancestry in YFV still accord well with the dual histories of colonialism and the slave trade, with areas of sylvatic transmission (such as Kedougou, Senegal) acting as enzootic/epidemic foci. PMID:19889759

  2. Epidemiological investigation of an outbreak of typhoid fever in Jorhat town of Assam, India

    PubMed Central

    Roy, Jashbeer Singh; Saikia, Lahari; Medhi, Mithu; Tassa, Dipak

    2016-01-01

    Background & objectives: Typhoid fever is a global health problem and is also endemic in India. An outbreak of fever occurred in January 2014 in Jorhat Town in Assam, India. Here we report the results of an investigation done to find out the aetiology and source of the outbreak. Methods: The affected areas were visited on January 23, 2014 by a team of Jorhat district Integrated Disease Surveillance Project personnel. A total of 13 blood samples from patients with fever as first symptom and six water samples were collected from the affected areas. The blood samples were cultured and isolates were identified using standard biochemical tests. Isolates were also tested for antimicrobial sensitivity. Widal test was performed on 10 of the 13 blood samples collected. Sanitary survey was carried out to find any leakage in the water supply and also the sewage system of the Jorhat town. Results: Blood culture yielded Salmonella enterica serovar Typhi in six (46.15%) patients whereas Widal test was positive in 10 (76.9%) of 13 patients. Water culture showed presumptive coliform count of >180/100 ml in two out of the six samples tested. Salmonella Typhi was also isolated from water culture of these two samples. Sanitary survey carried out in the affected places showed that the water supply pipes of urban water supply were in close proximity to the sewage drainage system and there were few leakages. Interpretation & conclusions: The outbreak occurred due to S. Typhi contaminating the water supply. Sanitation and immunization are the two most important components to be stressed to prevent such outbreaks. PMID:28256469

  3. Management of a Lassa fever outbreak, Rhineland-Palatinate, Germany, 2016.

    PubMed

    Ehlkes, Lutz; George, Maja; Samosny, Gerhard; Burckhardt, Florian; Vogt, Manfred; Bent, Stefan; Jahn, Klaus; Zanger, Philipp

    2017-09-01

    Due to rapid diagnosis and isolation of imported cases, community outbreaks of viral haemorrhagic fevers (VHF) are considered unlikely in industrialised countries. In March 2016, the first documented locally acquired case of Lassa fever (LF) outside Africa occurred, demonstrating the disease's potential as a cross-border health threat. We describe the management surrounding this case of LF in Rhineland-Palatinate - the German federal state where secondary transmission occurred. Twelve days after having been exposed to the corpse of a LF case imported from Togo, a symptomatic undertaker tested positive for Lassa virus RNA. Potential contacts were traced, categorised based on exposure risk, and monitored. Overall, we identified 21 contact persons with legal residency in Rhineland-Palatinate: seven related to the index case, 13 to the secondary case, and one related to both. The secondary case received treatment and recovered. Five contacts were quarantined and one was temporarily banned from work. No further transmission occurred. Based on the experience gained during the outbreak and a review of national and international guidelines, we conclude that exposure risk attributable to corpses may currently be underestimated, and we present suggestions that may help to improve the anti-epidemic response to imported VHF cases in industrialised countries.

  4. Value of syndromic surveillance within the Armed Forces for early warning during a dengue fever outbreak in French Guiana in 2006

    PubMed Central

    Meynard, Jean-Baptiste; Chaudet, Hervé; Texier, Gaetan; Ardillon, Vanessa; Ravachol, Françoise; Deparis, Xavier; Jefferson, Henry; Dussart, Philippe; Morvan, Jacques; Boutin, Jean-Paul

    2008-01-01

    Background A dengue fever outbreak occured in French Guiana in 2006. The objectives were to study the value of a syndromic surveillance system set up within the armed forces, compared to the traditional clinical surveillance system during this outbreak, to highlight issues involved in comparing military and civilian surveillance systems and to discuss the interest of syndromic surveillance for public health response. Methods Military syndromic surveillance allows the surveillance of suspected dengue fever cases among the 3,000 armed forces personnel. Within the same population, clinical surveillance uses several definition criteria for dengue fever cases, depending on the epidemiological situation. Civilian laboratory surveillance allows the surveillance of biologically confirmed cases, within the 200,000 inhabitants. Results It was shown that syndromic surveillance detected the dengue fever outbreak several weeks before clinical surveillance, allowing quick and effective enhancement of vector control within the armed forces. Syndromic surveillance was also found to have detected the outbreak before civilian laboratory surveillance. Conclusion Military syndromic surveillance allowed an early warning for this outbreak to be issued, enabling a quicker public health response by the armed forces. Civilian surveillance system has since introduced syndromic surveillance as part of its surveillance strategy. This should enable quicker public health responses in the future. PMID:18597694

  5. [Severe Yellow fever vaccine-associated disease: a case report and current overview].

    PubMed

    Slesak, Günther; Gabriel, Martin; Domingo, Cristina; Schäfer, Johannes

    2017-08-01

    History and physical examination  A 56-year-old man developed high fever with severe headaches, fatigue, impaired concentration skills, and an exanthema 5 days after a yellow fever (YF) vaccination. Laboratory tests  Liver enzymes and YF antibody titers were remarkably elevated. YF vaccine virus was detected in urine by PCR. Diagnosis and therapy  Initially, severe YF vaccine-associated visceral disease was suspected and treated symptomatically. Clinical Course  His fever ceased after 10 days in total, no organ failure developed. However, postencephalitic symptoms persisted with fatigue and impaired concentration, memory, and reading skills and partly incapability to work for over 3 months. A diagnosis was made of suspected YF vaccine-associated neurotropic disease. Conclusion  Severe vaccine-derived adverse effects need to be considered in the indication process for YF vaccination. © Georg Thieme Verlag KG Stuttgart · New York.

  6. [Vaccination against yellow fever among patients on immunosuppressors with diagnoses of rheumatic diseases].

    PubMed

    Mota, Licia Maria Henrique da; Oliveira, Ana Cristina Vanderley; Lima, Rodrigo Aires Corrêa; Santos-Neto, Leopoldo Luiz dos; Tauil, Pedro Luiz

    2009-01-01

    Yellow fever is endemic in some countries. The anti-yellow fever vaccine is the only effective means of protection but is contraindicated for immunocompromised patients. The aim of this paper was to report on a case series of rheumatological patients who were using immunosuppressors and were vaccinated against this disease. This was a retrospective study by means of a questionnaire applied to these patients, who were vaccinated 60 days before the investigation. Seventy patients of mean age 46 years were evaluated. Most of them were female (90%). There were cases of rheumatoid arthritis (54), systemic lupus erythematosus (11), spondyloarthropathy (5) and systemic sclerosis (2). The therapeutic schemes included methotrexate (42), corticosteroids (22), sulfasalazine (26), leflunomide (18), cyclophosphamide (3) and immunobiological agents (9). Sixteen patients (22.5%) reported some minor adverse effect. Among the eight patients using immunobiological agents, only one presented a mild adverse effect. Among these patients using immunosuppressors, adverse reactions were no more frequent than among immunocompetent individuals. This is the first study on this topic.

  7. Neurologic manifestations associated with an outbreak of typhoid fever, Malawi--Mozambique, 2009: an epidemiologic investigation.

    PubMed

    Sejvar, James; Lutterloh, Emily; Naiene, Jeremias; Likaka, Andrew; Manda, Robert; Nygren, Benjamin; Monroe, Stephan; Khaila, Tadala; Lowther, Sara A; Capewell, Linda; Date, Kashmira; Townes, David; Redwood, Yanique; Schier, Joshua; Barr, Beth Tippett; Demby, Austin; Mallewa, Macpherson; Kampondeni, Sam; Blount, Ben; Humphrys, Michael; Talkington, Deborah; Armstrong, Gregory L; Mintz, Eric

    2012-01-01

    The bacterium Salmonella enterica serovar Typhi causes typhoid fever, which is typically associated with fever and abdominal pain. An outbreak of typhoid fever in Malawi-Mozambique in 2009 was notable for a high proportion of neurologic illness. Describe neurologic features complicating typhoid fever during an outbreak in Malawi-Mozambique Persons meeting a clinical case definition were identified through surveillance, with laboratory confirmation of typhoid by antibody testing or blood/stool culture. We gathered demographic and clinical information, examined patients, and evaluated a subset of patients 11 months after onset. A sample of persons with and without neurologic signs was tested for vitamin B6 and B12 levels and urinary thiocyanate. Between March - November 2009, 303 cases of typhoid fever were identified. Forty (13%) persons had objective neurologic findings, including 14 confirmed by culture/serology; 27 (68%) were hospitalized, and 5 (13%) died. Seventeen (43%) had a constellation of upper motor neuron findings, including hyperreflexia, spasticity, or sustained ankle clonus. Other neurologic features included ataxia (22, 55%), parkinsonism (8, 20%), and tremors (4, 10%). Brain MRI of 3 (ages 5, 7, and 18 years) demonstrated cerebral atrophy but no other abnormalities. Of 13 patients re-evaluated 11 months later, 11 recovered completely, and 2 had persistent hyperreflexia and ataxia. Vitamin B6 levels were markedly low in typhoid fever patients both with and without neurologic signs. Neurologic signs may complicate typhoid fever, and the diagnosis should be considered in persons with acute febrile neurologic illness in endemic areas.

  8. Analysis of a Reverse Transcription Loop-mediated Isothermal Amplification (RT-LAMP) for yellow fever diagnostic.

    PubMed

    Nunes, Marcio R T; Vianez, João Lídio; Nunes, Keley N B; da Silva, Sandro Patroca; Lima, Clayton P S; Guzman, Hilda; Martins, Lívia C; Carvalho, Valéria L; Tesh, Robert B; Vasconcelos, Pedro F C

    2015-12-15

    Yellow Fever virus (YFV) is an important human pathogen in tropical areas of Africa and South America. Although an efficient vaccine is available and has been used since the early 1940s, sylvatic YFV transmission still occurs in forested areas where anthropogenic actions are present, such as mineral extraction, rearing livestock and agriculture, and ecological tourism. In this context, two distinct techniques based on the RT-PCR derived method have been previously developed, however both methods are expensive due to the use of thermo cyclers and labeled probes. We developed isothermal genome amplification, which is a rapid, sensitive, specific and low cost molecular approach for YFV genome detection. This assay used a set of degenerate primers designed for the NS1 gene and was able to amplify, within 30 min in isothermal conditions, the YFV 17D vaccine strain derived from an African wild prototype strain (Asibi), as well as field strains from Brazil, other endemic countries from South and Central America, and the Caribbean. The generic RT-LAMP assay could be helpful for YFV surveillance in field and rapid response during outbreaks in endemic areas. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. [Study of epidemiological characteristics and viral sources of dengue fever outbreak in Guangxi Zhuang Autonomous Region, 2014].

    PubMed

    Chen, M M; Tan, Y; Tang, Z Z; Lin, M; Zhou, K J; He, W T; Yang, Y P; Wang, J

    2016-10-10

    Objective: To understand the epidemiological characteristics and viral sources of dengue fever outbreak in Guangxi Zhuang Autonomous Region (Guangxi) in 2014. Methods: A combined analysis of epidemiological characteristics and genetic characteristics were performed in this study. The time, population and area distributions of the cases were analyzed. Serum samples were collected from dengue fever cases to detect NS1 antigen by using commercial ELISA kits according to the guideline of the manufacture. RT-PCR assay was conducted to detect dengue virus in NS1 positive samples. Phylogenetic tree based on E gene sequence of dengue virus were further analyzed. Results: During September-December 2014, an outbreak of dengue fever caused by dengue virus type 1 and 2 occurred in Guangxi, a total of 854 cases were reported without death, including 712 laboratory confirmed cases and 142 clinical diagnosed cases, in which 79.63 % (680/854) occurred during 22 September-21 October 2014. All the cases had typical dengue fever symptoms. Most cases occurred in Nanning and Wuzhou, in which 83.61 % (714/854) were in age group 15-59 years; 46.60 % (398/854) were staff or people engaged in commercial service. A total 526 serum samples were tested for dengue virus serotype by RT-PCR assay. Among 414 positive samples, 345 were positive for dengue virus type 1 (DENV-1) and 69 were positive for dengue virus type 2 (DENV-2), no DENV-3 and DENV-4 were detected. The results of phylogenetic analysis of E gene sequence indicated that the sequences of 99.12 % (113/114) of DENV-1 strains in Nanning in China shared 100.00 % homology with the isolate (SG EHI D1/529Y13) from Singapore in 2013, which belonged to the genotype Ⅰ; All the DENV-2 isolates from Wuzhou shared 99.80 % homology with the isolate (D14005) from Guangdong province, which belonged to genotype Cosmopolitan. Conclusions: The outbreak was caused by DENV-1 from Singapore and DENV-2 from Guangdong province in China. It is necessary

  10. The 2007 Rift Valley Fever Outbreak in Sudan

    PubMed Central

    Hassan, Osama Ahmed; Ahlm, Clas; Sang, Rosemary; Evander, Magnus

    2011-01-01

    Rift Valley fever (RVF) is a neglected, emerging, mosquito-borne disease with severe negative impact on human and animal health and economy. RVF is caused by RVF virus (RVFV) affecting humans and a wide range of animals. The virus is transmitted through bites from mosquitoes and exposure to viremic blood, body fluids, or tissues of infected animals. During 2007 a large RVF outbreak occurred in Sudan with a total of 747 confirmed human cases including 230 deaths (case fatality 30.8%); although it has been estimated 75,000 were infected. It was most severe in White Nile, El Gezira, and Sennar states near to the White Nile and the Blue Nile Rivers. Notably, RVF was not demonstrated in livestock until after the human cases appeared and unfortunately, there are no records or reports of the number of affected animals or deaths. Ideally, animals should serve as sentinels to prevent loss of human life, but the situation here was reversed. Animal contact seemed to be the most dominant risk factor followed by animal products and mosquito bites. The Sudan outbreak followed an unusually heavy rainfall in the country with severe flooding and previous studies on RVF in Sudan suggest that RVFV is endemic in parts of Sudan. An RVF outbreak results in human disease, but also large economic loss with an impact beyond the immediate influence on the directly affected agricultural producers. The outbreak emphasizes the need for collaboration between veterinary and health authorities, entomologists, environmental specialists, and biologists, as the best strategy towards the prevention and control of RVF. PMID:21980543

  11. Revisiting the liver in human yellow fever: virus-induced apoptosis in hepatocytes associated with TGF-beta, TNF-alpha and NK cells activity.

    PubMed

    Quaresma, Juarez A S; Barros, Vera L R S; Pagliari, Carla; Fernandes, Elaine R; Guedes, Fernanda; Takakura, Cleusa F H; Andrade, Heitor F; Vasconcelos, Pedro F C; Duarte, Maria I S

    2006-02-05

    Flavivirus infection as dengue and yellow fever persists as a terrible menace to pandemics, due to Aedes prevalence in the Americas. Yellow fever is characterized by hepatocyte damage, with steatosis, apoptosis and necrosis, mainly in the midzonal region of the liver, but the injury mechanism has not been studied at the light of recent knowledge, such as the advances in cell death mechanisms, inflammatory response and cytokine cell expression tools. We studied 53 human liver paraffin embedded blocks from patients who died with yellow fever, all with histological demonstration of higher prevalence of apoptosis over necrosis and mild disproportionate inflammatory response. Viral antigens were found most frequently in hepatocytes from the midzonal area than other lobule areas, as detected by specific immunohistochemistry. Infiltrating cell subpopulations showed mainly CD4+ T lymphocytes, with small numbers of CD8+ cytotoxic lymphocytes, CD20+ B lymphocytes, NKT+ cells and S100+ dendritic cells in the sites of inflammation, as compared to normal and leptospirosis liver blocks. Some cells expressed TNF-alpha and IFN-gamma, but a much more intense proportion of TGF-beta expressing cells were found, suggesting both a Th1 and Th3 patterns of immune response in yellow fever. Most affected hepatocyte presented apoptosis markers that appear at the cell death main pathway in this infection. Viral antigens, which production could interfere in hepatocyte biology, could induce the activation of apoptosis cascade, but TGF-beta was also an apoptosis promoter. Our finding supports the key effect of the yellow fever virus in hepatocyte injury, resulting in prevalence of apoptosis over necrosis, aside from a TGF-beta action induced by the inflammatory response.

  12. Thiosemicarbazones and Phthalyl-Thiazoles compounds exert antiviral activity against yellow fever virus and Saint Louis encephalitis virus.

    PubMed

    Pacca, Carolina Colombelli; Marques, Rafael Elias; Espindola, José Wanderlan P; Filho, Gevânio B O Oliveira; Leite, Ana Cristina Lima; Teixeira, Mauro Martins; Nogueira, Mauricio L

    2017-03-01

    Arboviruses, arthropod-borneviruses, are frequency associated to human outbreak and represent a serious health problem. The genus Flavivirus, such as Yellow Fever Virus (YFV) and Saint Louis Encephalitis Virus (SLEV), are important pathogens with high morbidity and mortality worldwide. In Brazil, YFV is maintained in sylvatic cycle, but many cases are notified annually, despite the efficiency of vaccine. SLEV causes an acute encephalitis and is widely distributed in the Americas. There is no specific antiviral drugs for these viruses, only supporting treatment that can alleviate symptoms and prevent complications. Here, we evaluated the potential anti-YFV and SLEV activity of a series of thiosemicarbazones and phthalyl-thiazoles. Plaque reduction assay, flow cytometry, immunofluorescence and cellular viability were used to test the compounds in vitro. Treated cells showed efficient inhibition of the viral replication at concentrations that presented minimal toxicity to cells. The assays showed that phthalyl-thiazole and phenoxymethyl-thiosemicarbazone reduced 60% of YFV replication and 75% of SLEV replication. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  13. Evaluation of movement restriction zone sizes in controlling classical swine fever outbreaks

    USDA-ARS?s Scientific Manuscript database

    The objective of this study was to compare the movement restriction zone sizes of 3-km, 5-km, 9-km, and 11-km with that of 7-km in controlling a classical swine fever (CSF) outbreak. Three assumptions of compliance level were considered: baseline, baseline ±10%, and baseline ±15%. The compliance lev...

  14. Chikungunya fever outbreak identified in North Bali, Indonesia.

    PubMed

    Sari, Kartika; Myint, Khin Saw Aye; Andayani, Ayu Rai; Adi, Putu Dwi; Dhenni, Rama; Perkasa, Aditya; Ma'roef, Chairin Nisa; Witari, Ni Putu Diah; Megawati, Dewi; Powers, Ann M; Jaya, Ungke Anton

    2017-07-01

    Chikungunya virus (CHIKV) infections have been reported sporadically within the last 5 years in several areas of Indonesia including Bali. Most of the reports, however, have lacked laboratory confirmation. A recent fever outbreak in a village in the North Bali area was investigated using extensive viral diagnostic testing including both molecular and serological approaches. Ten out of 15 acute febrile illness samples were confirmed to have CHIKV infection by real-time PCR or CHIKV-specific IgM enzyme-linked immunosorbent assay (ELISA). The outbreak strain belonged to the Asian genotype with highest homology to other CHIKV strains currently circulating in Indonesia. The results are of public health concern particularly because Bali is a popular tourist destination in Indonesia and thereby the potential to spread the virus to non-endemic areas is high. KY885022, KY885023, KY885024, KY885025, KY885026, KY885027. © The Author 2017. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Molecular epidemiological characteristics of Streptococcus pyogenes strains involved in an outbreak of scarlet fever in China, 2011.

    PubMed

    You, Yuan Hai; Song, Yan Yan; Yan, Xiao Mei; Wang, Hai Bin; Zhang, Meng Han; Tao, Xiao Xia; Li, Lei Lei; Zhang, Yu Xin; Jiang, Xi Hong; Zhang, Bing Hua; Zhou, Hao; Xiao, Di; Jin, Lian Mei; Feng, Zi Jian; Luo, Feng Ji; Zhang, Jian Zhong

    2013-11-01

    To investigate molecular characterization of streptococcus pyogenes isolates involved in an outbreak of scarlet fever in China in 2011. Seventy-four Streptococcal pyogenes involved in an outbreak of scarlet fever were isolated from pediatric patients in the areas with high incidence in China from May to August of 2011. Emm genotyping, pulsed-field gel electrophoresis (PFGE), superantigen (SAg) genes and antimicrobial susceptibility profiling were analyzed for these isolates. A total of 4 different emm types were identified. Emm12 was the most prevalent type which contained four predominating PFGE patterns corresponding to four different virulence and superantigen profiles. Emm12 (79.7%) and emm1 (14.9%) accounted for approximately 94% of all the isolates. The speA gene was all negative in emm12 isolates and positive in emm1 isolates. All strains were resistant to erythromycin, and 89.4% of them were resistant to erythromycin, tracycline, and clindamycin simultaneously. Several highly diversified clones with a high macrolide resistance rate comprise a predominant proportion of circulating strains, though no new emm type was found in this outbreak. The data provide a baseline for further surveillance of scarlet fever, which may contribute to the explanation of the outbreak and development of a GAS vaccine in China. Copyright © 2013 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  16. EXPERIMENTAL STUDIES ON YELLOW FEVER IN NORTHERN PERU.

    PubMed

    Noguchi, H; Kligler, I J

    1921-01-31

    Fourteen typical cases of yellow fever were studied in northern Peru during an epidemic occurring in 1920, nine in Payta in March and April, and five in Morropon and Piura in April and May. The method of investigation was similar to that previously employed, but as the laboratory facilities were very meager certain changes were required. Although in Payta the work was handicapped by the lack of electric light, the scarcity of water and animal food, the unsuitability of the guinea pigs for inoculation, and the changes in culture media due to age, the results obtained under these adverse conditions were by no means negative. While in no instance was there a typical infection produced in animals, either by direct inoculation of blood or with culture materials, yet certain guinea pigs in each series showed temporary febrile reactions or definite hemorrhagic lesions of the lungs indicative of a mild leptospira infection. Direct search for Leptospira icteroides in the blood of patients or in culture materials was not made because the dark-field microscope could not be used. Subsequently, at Piura, the laboratory facilities were vastly, improved, the use of the dark-field microscope was made possible by means of a storage battery, and a fresh stock of young healthy guinea pigs was received from New York, and fresh rabbit serum obtained in Piura. In the study of the materials obtained from five cases of yellow fever in Morropon all these added facilities were taken advantage of, with the result that the outcome was positive and convincing. Cultures from the five cases were examined after 11, 12, and 13 days, and in those from three cases living leptospiras were found. By inoculation into suitable guinea pigs of culture material from these five cases, irrespective of whether or not leptospiras were detected under the dark-field microscope, a typical Leptospira icteroides infection was produced from four of the five cases. In one of these no leptospira had been detected in

  17. Prevention of yellow fever in persons traveling to the tropics.

    PubMed

    Monath, Thomas P; Cetron, Martin S

    2002-05-15

    Yellow fever (YF) is a potentially lethal mosquito-borne viral hemorrhagic fever endemic in Africa and South America. Nine million tourists annually arrive in countries where YF is endemic, and fatal cases of YF have occurred recently in travelers. In this article, we review the risk factors for YF during travel and the use of YF 17D vaccine to prevent the disease. Although the vaccine is highly effective and has a long history of safe use, the occurrence of rare, fatal adverse events has raised new concerns. These events should not deter travelers to areas where YF is endemic from being immunized, because the risk of YF infection and illness may be high in rural areas and cannot be easily defined by existing surveillance. To avoid unnecessary vaccination, physicians should vaccinate persons at risk on the basis of knowledge of the epidemiology of the disease, reports of epidemic activity, season, and the likelihood of exposure to vector mosquitoes.

  18. [Yellow fever virus, dengue 2 and other arboviruses isolated from mosquitos, in Burkina Faso, from 1983 to 1986. Entomological and epidemiological considerations].

    PubMed

    Robert, V; Lhuillier, M; Meunier, D; Sarthou, J L; Monteny, N; Digoutte, J P; Cornet, M; Germain, M; Cordellier, R

    1993-01-01

    An arbovirus surveillance was carried out in Burkina Faso from 1983 to 1986. It was based on crepuscular catches of mosquitoes on human bait in some wooded areas and in one town. The total collection was 228 catches with an average of 8 men per catch. The total number of mosquitoes caught was 44,956 among which 32,010 potential vector of yellow fever; all these mosquitoes were analysed for arbovirology. In the south-western part of the country (region of Bobo-Dioulasso), surveillance was conducted each year from August to November, whilst the circulation of Aedes-borne arboviruses is well known to be favoured. In 1983, 1984 and 1986, seven strains of yellow fever virus were isolated in circumstances remarkably similar. They came from selvatic areas and never from the town. They concerned only Aedes (Stegomyia) luteocephalus which is the very predominant potential vector of yellow fever in the region. They were obtained in low figure, between 1 and 4 per year. They occurred from 27th of October to 21th of November. These observations confirm that the southern portion of the Sudan savanna zone of West Africa is the setting of a customary circulation of yellow fever virus and therefore belongs to the endemic emergence zone. In 1986, two strains of dengue 2 virus were isolated. One concerned Ae. luteocephalus from the selvatic area, the other Ae. (St.) aegypti from the heart of town. These data suggest two distinct cycles for dengue 2 virus, one urban and one selvatic, which could coexist simultaneously in the same region. In the south-eastern part of the country (region of Fada-N'Gourma) a yellow fever epidemic occurred between September and December 1983; its study has enable to precise their entomological aspects. The entomological inoculation rate of yellow fever virus has been evaluated to 22 infected bites per man during the month of october, for a man living close to forest gallery. 25 strains of yellow fever virus strains was isolated from Ae. (Diceromyia

  19. Two outbreaks of classical swine fever in wild boar in France.

    PubMed

    Pol, F; Rossi, S; Mesplède, A; Kuntz-Simon, G; Le Potier, M-F

    2008-06-21

    In 2002 and 2003, two successive outbreaks of classical swine fever were declared in wild boar in northern France. The first was in Moselle, near the town of Thionville and the border with Luxembourg, and the second was in the northern Vosges area, near the German border. The outbreaks were investigated by serological and virological diagnosis of dead or shot animals. Hunting restrictions were applied to limit the spread of the outbreaks. The virus was detected eight times between April and July 2002 in the Thionville area, an area well delimited by natural or artificial barriers such as rivers or highways. Cooperation between the authorities concerned was good, and hunting restrictions were applied for one year. No virus was detected after July 2002 and the Thionville outbreak was officially considered over in March 2005. In the northern Vosges the situation was different, with no barriers to animal movements, continuous forest, difficulties in establishing hunting restrictions in this huge area, and the circulation of the virus in Germany close to the frontier. Virus of a different strain from that isolated in the Thionville outbreak was still being isolated in the northern Vosges in 2004, and owing to the failure of the hunting restrictions, the French health authorities decided to vaccinate wild boar.

  20. MEK/ERK activation plays a decisive role in yellow fever virus replication: implication as an antiviral therapeutic target.

    PubMed

    Albarnaz, Jonas D; De Oliveira, Leonardo C; Torres, Alice A; Palhares, Rafael M; Casteluber, Marisa C; Rodrigues, Claudiney M; Cardozo, Pablo L; De Souza, Aryádina M R; Pacca, Carolina C; Ferreira, Paulo C P; Kroon, Erna G; Nogueira, Maurício L; Bonjardim, Cláudio A

    2014-11-01

    Exploiting the inhibition of host signaling pathways aiming for discovery of potential antiflaviviral compounds is clearly a beneficial strategy for the control of life-threatening diseases caused by flaviviruses. Here we describe the antiviral activity of the MEK1/2 inhibitor U0126 against Yellow fever virus 17D vaccine strain (YFV-17D). Infection of VERO cells with YFV-17D stimulates ERK1/2 phosphorylation early during infection. Pharmacological inhibition of MEK1/2 through U0126 treatment of VERO cells blockades not only the YFV-stimulated ERK1/2 phosphorylation, but also inhibits YFV replication by ∼99%. U0126 was also effective against dengue virus (DENV-2 and -3) and Saint-Louis encephalitis virus (SLEV). Levels of NS4AB, as detected by immunofluorescence, are diminished upon treatment with the inhibitor, as well as the characteristic endoplasmic reticulum membrane invagination stimulated during the infection. Though not protective, treatment of YFV-infected, adult BALB/c mice with U0126 resulted in significant reduction of virus titers in brains. Collectively, our data suggest the potential targeting of the MEK1/2 kinase as a therapeutic tool against diseases caused by flaviviruses such as yellow fever, adverse events associated with yellow fever vaccination and dengue. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. An outbreak of dengue fever in St. Croix (U. S. Virgin Islands), 2005.

    USDA-ARS?s Scientific Manuscript database

    In the summer of 2005, an outbreak of dengue virus serotype-2 with cases of dengue hemorrhagic fever (DHF) occurred in St. Croix, US Virgin Islands. The medical records of all dengue laboratory-positive patients either seen in the Emergency Department of or admitted to the Governor Juan F. Luis Hosp...

  2. ETIOLOGY OF YELLOW FEVER : VII. DEMONSTRATION OF LEPTOSPIRA ICTEROIDES IN THE BLOOD, TISSUES, AND URINE OF YELLOW FEVER PATIENTS AND OF ANIMALS EXPERIMENTALLY INFECTED WITH THE ORGANISM.

    PubMed

    Noguchi, H

    1919-08-01

    Examinations of fresh blood from yellow fever patients by means of the dark-field microscope, made in more than twenty-seven cases, revealed in three cases the presence of Leptospira icteroides. In no instance was a large number of organisms found, a long search being required before one was encountered. The injection of the blood into guinea pigs from two of the three positive cases induced in the animals a fatal infection, while the blood from the third positive case failed to infect the guinea pigs fatally. Careful but by no means exhaustive dark-field searches for the leptospira with fresh specimens of blood from the remaining cases of yellow fever ended without positive findings, although four of the specimens, when injected into guinea pigs, caused a fatal leptospira infection. Stained blood film preparations from the corresponding cases were also examined, but the percentage showing the leptospira in the blood was no greater than that found by examination in the fresh state with the dark-field microscope. In fact, owing to the defective stains that were available at the time of the investigation a great many slides did not take the proper coloration with Giemsa's or Wright's stain and could not be relied upon. Regarding the presence of Leptospira icteroides in various organs both dark-field and stained films were examined. In only one instance so far a few organisms were detected in the emulsion of liver taken shortly after death from a case dying on the 4th day of yellow fever. This part of the work will be reported later upon completion. Examinations of the urine from different cases of yellow fever were made both by dark-field microscope and by inoculation into guinea pigs. The results were totally negative in thirteen cases, including many convalescents, but in one case one of the guinea pigs inoculated with 10 cc. of the urine came down on the 15th day with suggestive symptoms (suspicion of jaundice, and some hemorrhagic and parenchymatous lesions of

  3. Rift Valley Fever Outbreaks in Mauritania and Related Environmental Conditions

    PubMed Central

    Caminade, Cyril; Ndione, Jacques A.; Diallo, Mawlouth; MacLeod, Dave A.; Faye, Ousmane; Ba, Yamar; Dia, Ibrahima; Morse, Andrew P.

    2014-01-01

    Four large outbreaks of Rift Valley Fever (RVF) occurred in Mauritania in 1998, 2003, 2010 and 2012 which caused lots of animal and several human deaths. We investigated rainfall and vegetation conditions that might have impacted on RVF transmission over the affected regions. Our results corroborate that RVF transmission generally occurs during the months of September and October in Mauritania, similarly to Senegal. The four outbreaks were preceded by a rainless period lasting at least a week followed by heavy precipitation that took place during the second half of the rainy season. First human infections were generally reported three to five weeks later. By bridging the gap between meteorological forecasting centers and veterinary services, an early warning system might be developed in Senegal and Mauritania to warn decision makers and health services about the upcoming RVF risk. PMID:24413703

  4. Diagnosis of imported Ugandan typhoid fever based on local outbreak information: A case report.

    PubMed

    Ota, Shinichiro; Maki, Yohei; Mori, Kazuma; Hamamoto, Takaaki; Kurokawa, Atsushi; Ishihara, Masashi; Yamamoto, Takayuki; Imai, Kazuo; Misawa, Kazuhisa; Yuki, Atsushi; Fujikura, Yuji; Maeda, Takuya; Kawana, Akihiko

    2016-11-01

    Re-emerging multidrug-resistant typhoid fever is becoming a worldwide threat, especially in East Africa. At the beginning of 2015, an outbreak of typhoid fever started in the capital city of Uganda, and 1940 suspected cases were reported by 5 March 2015. In this report, we describe a case of typhoid fever caused by a MDR strain with HIV infection and hemoglobin S-syndrome thalassemia in an Ugandan from Kampala City. It is essential to consider MDR strains of Salmonella enterica serovar Typhi infections, including fluoroquinolone-resistant strains, in patients from Africa and Southeast Asia. Copyright © 2016 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  5. IMMUNITY TO YELLOW FEVER ENCEPHALITIS OF MONKEYS AND MICE IMMUNIZED BY NEURAL AND EXTRANEURAL ROUTES

    PubMed Central

    Fox, John P.

    1943-01-01

    Monkeys and mice surviving cerebral infection with yellow fever virus of relatively avirulent strains have been found to resist maximal intracerebral doses of yellow fever virus of a highly neurotropic strain. Such animals, however, do not resist more than very small doses of intracerebrally inoculated virus of Eastern equine encephalomyelitis. Animals immunized by extraneural routes, on the other hand, are not uniformly resistant to neural infection with neurotropic yellow fever virus. Monkeys which have undergone systemic infection with virus of the avirulent 17D strain or of several jungle strains resist only small intracerebral doses of neurotropic virus; while mice, even when possessed of very high serum-antibody levels as the result of intraperitoneal hyperimmunization, manifest only an irregular resistance to intracerebral challenge inocula. The difference in the resistance of neurally and extraneurally immunized animals is not related to similar differences in the levels of protective antibody in the sera. Indeed, the average of the serum-antibody titers of the hyperimmune mice is several times that of the intracerebral immunes. A possibly significant relation does exist, however, between the resistance of mice to neural infection and the content of protective antibody in the brain. The protective activity of suspensions of brains from mice surviving cerebral infection was found to be several times that of brain suspensions from the hyperimmunized animals. It is concluded that the superior resistance to neural infection of animals whose immunity results from a previous non-fatal infection of the nervous system is effected by a specific local mechanism which is based at least in part upon an increased concentration of antibody in the cerebral tissue. PMID:19871299

  6. Investigation of a community outbreak of typhoid fever associated with drinking water

    PubMed Central

    2009-01-01

    Background This report is about the investigation of an outbreak of typhoid fever claimed three human lives and left more than 300 people suffered within one week. The aim of this report is to draw the attention of global health community towards the areas that are still far from basic human essentialities. Methods A total of 250 suspected cases of typhoid fever were interviewed, out of which 100 were selected for sample collection on the basis of criteria included temperature > 38°C since the onset of outbreak, abdominal discomfort, diarrhea, vomiting and weakness. Food and water samples were also collected and analyzed microbiologically. Results Inhabitants of village lived in poor and unhygienic conditions with no proper water supply or sewage disposal facilities and other basic necessities of life. They consumed water from a nearby well which was the only available source of drinking water. Epidemiological evidences revealed the gross contamination of well with dead and decaying animal bodies, their fecal material and garbage. Microbiological analysis of household and well water samples revealed the presence of heavy bacterial load with an average total aerobic count 106-109 CFU/ml. A number of Gram positive and Gram negative bacteria including Escherichia coli, Klebsiella, Bacillus species, Staphylococcus species, Enterobacter species, and Pseudomonas aeruginosa were isolated. Lab investigations confirmed the presence of multidrug resistant strain of Salmonella enterica serovar Typhi in 100% well water, 65% household water samples and 2% food items. 22% of clinical stool samples were tested positive with Salmonella enterica serover Typhi Conclusions This study indicated the possible involvement of well water in outbreaks. In order to avoid such outbreaks in future, we contacted the local health authorities and urged them to immediately make arrangements for safe drinking water supply. PMID:20021691

  7. Learning immunology from the yellow fever vaccine: innate immunity to systems vaccinology.

    PubMed

    Pulendran, Bali

    2009-10-01

    Despite their great success, we understand little about how effective vaccines stimulate protective immune responses. Two recent developments promise to yield such understanding: the appreciation of the crucial role of the innate immune system in sensing microorganisms and tuning immune responses, and advances in systems biology. Here I review how these developments are yielding insights into the mechanism of action of the yellow fever vaccine, one of the most successful vaccines ever developed, and the broader implications for vaccinology.

  8. Environmental Survey of Drinking Water Sources in Kampala, Uganda, during a Typhoid Fever Outbreak.

    PubMed

    Murphy, J L; Kahler, A M; Nansubuga, I; Nanyunja, E M; Kaplan, B; Jothikumar, N; Routh, J; Gómez, G A; Mintz, E D; Hill, V R

    2017-12-01

    In 2015, a typhoid fever outbreak began in downtown Kampala, Uganda, and spread into adjacent districts. In response, an environmental survey of drinking water source types was conducted in areas of the city with high case numbers. A total of 122 samples was collected from 12 source types and tested for Escherichia coli , free chlorine, and conductivity. An additional 37 grab samples from seven source types and 16 paired large volume (20 liter) samples from wells and springs were also collected and tested for the presence of Salmonella enterica serovar Typhi. Escherichia coli was detected in 60% of kaveras (drinking water sold in plastic bags) and 80% of refilled water bottles; free chlorine was not detected in either source type. Most jerry cans (68%) contained E. coli and had free chlorine residuals below the WHO-recommended level of 0.5 mg/liter during outbreaks. Elevated conductivity readings for kaveras, refilled water bottles, and jerry cans (compared to treated surface water supplied by the water utility) suggested that they likely contained untreated groundwater. All unprotected springs and wells and more than 60% of protected springs contained E. coli Water samples collected from the water utility were found to have acceptable free chlorine levels and no detectable E. coli While S Typhi was not detected in water samples, Salmonella spp. were detected in samples from two unprotected springs, one protected spring, and one refilled water bottle. These data provided clear evidence that unregulated vended water and groundwater represented a risk for typhoid transmission. IMPORTANCE Despite the high incidence of typhoid fever globally, relatively few outbreak investigations incorporate drinking water testing. During waterborne disease outbreaks, measurement of physical-chemical parameters, such as free chlorine residual and electrical conductivity, and of microbiological parameters, such as the presence of E. coli or the implicated etiologic agent, in drinking

  9. Environmental Survey of Drinking Water Sources in Kampala, Uganda, during a Typhoid Fever Outbreak

    PubMed Central

    Kahler, A. M.; Nansubuga, I.; Nanyunja, E. M.; Kaplan, B.; Jothikumar, N.; Routh, J.; Gómez, G. A.; Mintz, E. D.; Hill, V. R.

    2017-01-01

    ABSTRACT In 2015, a typhoid fever outbreak began in downtown Kampala, Uganda, and spread into adjacent districts. In response, an environmental survey of drinking water source types was conducted in areas of the city with high case numbers. A total of 122 samples was collected from 12 source types and tested for Escherichia coli, free chlorine, and conductivity. An additional 37 grab samples from seven source types and 16 paired large volume (20 liter) samples from wells and springs were also collected and tested for the presence of Salmonella enterica serovar Typhi. Escherichia coli was detected in 60% of kaveras (drinking water sold in plastic bags) and 80% of refilled water bottles; free chlorine was not detected in either source type. Most jerry cans (68%) contained E. coli and had free chlorine residuals below the WHO-recommended level of 0.5 mg/liter during outbreaks. Elevated conductivity readings for kaveras, refilled water bottles, and jerry cans (compared to treated surface water supplied by the water utility) suggested that they likely contained untreated groundwater. All unprotected springs and wells and more than 60% of protected springs contained E. coli. Water samples collected from the water utility were found to have acceptable free chlorine levels and no detectable E. coli. While S. Typhi was not detected in water samples, Salmonella spp. were detected in samples from two unprotected springs, one protected spring, and one refilled water bottle. These data provided clear evidence that unregulated vended water and groundwater represented a risk for typhoid transmission. IMPORTANCE Despite the high incidence of typhoid fever globally, relatively few outbreak investigations incorporate drinking water testing. During waterborne disease outbreaks, measurement of physical-chemical parameters, such as free chlorine residual and electrical conductivity, and of microbiological parameters, such as the presence of E. coli or the implicated etiologic agent, in

  10. Yellow fever vector live-virus vaccines: West Nile virus vaccine development.

    PubMed

    Arroyo, J; Miller, C A; Catalan, J; Monath, T P

    2001-08-01

    By combining molecular-biological techniques with our increased understanding of the effect of gene sequence modification on viral function, yellow fever 17D, a positive-strand RNA virus vaccine, has been manipulated to induce a protective immune response against viruses of the same family (e.g. Japanese encephalitis and dengue viruses). Triggered by the emergence of West Nile virus infections in the New World afflicting humans, horses and birds, the success of this recombinant technology has prompted the rapid development of a live-virus attenuated candidate vaccine against West Nile virus.

  11. Molecular and serological studies on the Rift Valley fever outbreak in Mauritania in 2010.

    PubMed

    Jäckel, S; Eiden, M; El Mamy, B O; Isselmou, K; Vina-Rodriguez, A; Doumbia, B; Groschup, M H

    2013-11-01

    Rift Valley fever virus (RVFV) is a vector-borne RNA virus affecting humans, livestock and wildlife. In October/November 2010, after a period of unusually heavy rainfall, a Rift Valley fever outbreak occurred in northern Mauritania causing clinical cases in cattle, sheep, goats and camels, 21 of which were of lethal outcome. The aim of this study was to obtain further information on the continuation of RVF virus activity and spread in animal species in Mauritania after this outbreak. We therefore tested sera from small ruminants, cattle and camels for the presence of viral RNA and antibodies against RVFV. These sera were collected in different parts of the country from December 2010 to February 2011 and tested with three different ELISAs and an indirect immunofluorescence assay. The results show a high seroprevalence of RVFV IgM and IgG antibodies of about 57% in all animals investigated. Moreover, in four camel sera, viral RNA was detected emphasizing the important role camels played during the latest RVF outbreak in Mauritania. The study demonstrates the continuous spread of RVFV in Mauritania after initial emergence and highlights the potential role of small ruminants and camels in virus dissemination. © 2013 Blackwell Verlag GmbH.

  12. Administration of yellow fever vaccine in patients with egg allergy.

    PubMed

    Rutkowski, K; Ewan, P W; Nasser, S M

    2013-01-01

    The population of large parts of Africa, South America and travellers to these areas are at risk of yellow fever (YF) with a 50% mortality risk. Yellow fever vaccine (YFV) propagated in hens' eggs confers protection in 95% of the vaccinated. The rate of anaphylaxis for YFV ranges from 0.42 to 1.8/100,000 doses with most cases considered to be due to egg allergy. Egg allergy is a contraindication for the YFV. Nevertheless, the potential fatal sequelae from YF give the incentive to protect everyone at risk irrespective of their allergic status. Six subjects who had had a recent reaction to egg and who were travelling to endemic areas (3 adults and 3 children) underwent skin prick tests (SPT) with undiluted YFV and egg extract. Intradermal tests for YFV were undertaken at a 1:10 dilution. In 4 egg-allergic patients with a positive SPT to YFV, a 7-step desensitization protocol was used. A 2-step (10 + 90%) protocol was used in the 2 subjects with a negative YFV SPT. Premedication was not administered. All 6 patients were successfully vaccinated. Four patients completed desensitization: 1 developed mild local erythema at the injection site, 1 had fleeting generalized urticaria with local erythema/angioedema and 2 did not experience any adverse reactions. Patients who received YFV in 2 steps developed no adverse reactions. We describe the successful administration of YFV in 6 egg-allergic patients. The Cambridge Allergy 7-step protocol allows for its safe administration in patients with positive SPT to YFV. A 2-step protocol can be used in patients with negative YFV SPT. Copyright © 2013 S. Karger AG, Basel.

  13. Hemorrhagic Fevers - Multiple Languages

    MedlinePlus

    ... dialect) (繁體中文) Expand Section Vaccine Information Statement (VIS) -- Yellow Fever Vaccine: What You Need to Know - English PDF Vaccine Information Statement (VIS) -- Yellow Fever Vaccine: What You Need to Know - 繁體中文 (Chinese, Traditional ( ...

  14. Population Explosions of Tiger Moth Lead to Lepidopterism Mimicking Infectious Fever Outbreaks

    PubMed Central

    Wills, Pallara Janardhanan; Anjana, Mohan; Nitin, Mohan; Varun, Raghuveeran; Sachidanandan, Parayil; Jacob, Tharaniyil Mani; Lilly, Madhavan; Thampan, Raghava Varman; Karthikeya Varma, Koyikkal

    2016-01-01

    Lepidopterism is a disease caused by the urticating scales and toxic fluids of adult moths, butterflies or its caterpillars. The resulting cutaneous eruptions and systemic problems progress to clinical complications sometimes leading to death. High incidence of fever epidemics were associated with massive outbreaks of tiger moth Asota caricae adult populations during monsoon in Kerala, India. A significant number of monsoon related fever characteristic to lepidopterism was erroneously treated as infectious fevers due to lookalike symptoms. To diagnose tiger moth lepidopterism, we conducted immunoblots for tiger moth specific IgE in fever patients’ sera. We selected a cohort of patients (n = 155) with hallmark symptoms of infectious fevers but were tested negative to infectious fevers. In these cases, the total IgE was elevated and was detected positive (78.6%) for tiger moth specific IgE allergens. Chemical characterization of caterpillar and adult moth fluids was performed by HPLC and GC-MS analysis and structural identification of moth scales was performed by SEM analysis. The body fluids and chitinous scales were found to be highly toxic and inflammatory in nature. To replicate the disease in experimental model, wistar rats were exposed to live tiger moths in a dose dependant manner and observed similar clinico-pathological complications reported during the fever epidemics. Further, to link larval abundance and fever epidemics we conducted cointegration test for the period 2009 to 2012 and physical presence of the tiger moths were found to be cointegrated with fever epidemics. In conclusion, our experiments demonstrate that inhalation of aerosols containing tiger moth fluids, scales and hairs cause systemic reactions that can be fatal to human. All these evidences points to the possible involvement of tiger moth disease as a major cause to the massive and fatal fever epidemics observed in Kerala. PMID:27073878

  15. [City-laboratory: Campinas and yellow fever at the dawn of the Republican era].

    PubMed

    Martins, Valter

    2015-01-01

    In the late nineteenth century, there were yellow fever epidemics in Campinas. Considered a seaside disease, the fever startled lay people and physicians. The scientific debate about the etiology of the disease left the domain of magazines and medical correspondence to orient political and sanitary actions. In order to combat the disease, the city began to resemble a laboratory and experienced its "era of sanitation and demolition," with victories over the ailment and inconvenience to the public. The State Sanitary Commission led by Emilio Ribas, aware of Finlay's Culicidae theory, rehearsed in Campinas what would happen with Oswaldo Cruz and Pereira Passos in Rio de Janeiro. The novelty of combating mosquitoes coexisted with age-old practices dear to miasmatic theory, such as disinfection.

  16. Construction and characterization of a recombinant yellow fever virus stably expressing Gaussia luciferase.

    PubMed

    Kassar, Telissa C; Magalhães, Tereza; S, José V J; Carvalho, Amanda G O; Silva, Andréa N M R DA; Queiroz, Sabrina R A; Bertani, Giovani R; Gil, Laura H V G

    2017-01-01

    Yellow fever is an arthropod-borne viral disease that still poses high public health concerns, despite the availability of an effective vaccine. The development of recombinant viruses is of utmost importance for several types of studies, such as those aimed to dissect virus-host interactions and to search for novel antiviral strategies. Moreover, recombinant viruses expressing reporter genes may greatly facilitate these studies. Here, we report the construction of a recombinant yellow fever virus (YFV) expressing Gaussia luciferase (GLuc) (YFV-GLuc). We show, through RT-PCR, sequencing and measurement of GLuc activity, that stability of the heterologous gene was maintained after six passages. Furthermore, a direct association between GLuc expression and viral replication was observed (r2=0.9967), indicating that measurement of GLuc activity may be used to assess viral replication in different applications. In addition, we evaluated the use of the recombinant virus in an antiviral assay with recombinant human alfa-2b interferon. A 60% inhibition of GLuc expression was observed in cells infected with YFV-GLuc and incubated with IFN alfa-2b. Previously tested on YFV inhibition by plaque assays indicated a similar fold-decrease in viral replication. These results are valuable as they show the stability of YFV-GLuc and one of several possible applications of this construct.

  17. Occurrence of Autoimmune Diseases Related to the Vaccine against Yellow Fever

    PubMed Central

    Oliveira, Ana Cristina Vanderley; Maria Henrique da Mota, Licia; dos Santos-Neto, Leopoldo Luiz; De Carvalho, Jozélio Freire; Caldas, Iramaya Rodrigues; Martins Filho, Olindo Assis; Tauil, Pedro Luis

    2014-01-01

    Yellow fever is an infectious disease, endemic in South America and Africa. This is a potentially serious illness, with lethality between 5 and 40% of cases. The most effective preventive vaccine is constituted by the attenuated virus strain 17D, developed in 1937. It is considered safe and effective, conferring protection in more than 90% in 10 years. Adverse effects are known as mild reactions (allergies, transaminases transient elevation, fever, headache) and severe (visceral and neurotropic disease related to vaccine). However, little is known about its potential to induce autoimmune responses. This systematic review aims to identify the occurrence of autoinflammatory diseases related to 17D vaccine administration. Six studies were identified describing 13 possible cases. The diseases were Guillain-Barré syndrome, multiple sclerosis, multiple points evanescent syndrome, acute disseminated encephalomyelitis, autoimmune hepatitis, and Kawasaki disease. The data suggest that 17D vaccination may play a role in the mechanism of loss of self-tolerance. PMID:25405025

  18. [Investigation surrounding a fatal case of yellow fever in Côte d'Ivoire in 1999].

    PubMed

    Akoua-Koffi, C; Diarrassouba, S; Bénié, V B; Ngbichi, J M; Bozoua, T; Bosson, A; Akran, V; Carnevale, P; Ehouman, A

    2001-08-01

    Côte d'Ivoire is an endemic country for yellow fever, but no case was officially notified in recent years. In July 1999, however, one fatal case was reported. A German citizen was infected in the national park of Comoe, in the north eastern area of the country. In order to evaluate the extent of amaril virus circulation and the risk for local people, a virological, entomological and epidemiological investigation was carried out by the ministry of health, the OCCGE, the Côte d'Ivoire Pasteur Institute (IPCI) and the World Health Organisation in the area where the fatal case had been staying. 18 suspected and 24 confirmed mosquito catchers were identified by interview and a blood specimen was collected from each of them. In addition, 159 batches of mosquitoes from which 94 batches of potential vectors were collected; among the suspected cases, 22% were immunised against yellow fever. Serological and virological analyses were made at IPCI and the Paris Pasteur Institute by ELISA technique and isolation on cells cultures and newborn mice. All the suspicious sera and 87.5% of the catchers were positive for IgG anti-amaril virus. One catcher's serum was positive for IgM anti-amaril virus. 11 suspected sera were positive for IgG anti-dengue virus with 1 positive for IgM. 1 strain of amaril virus and 3 strains of Zika virus were isolated from mosquitoes at IPCI and confirmed by CRORA in Dakar. These results indicated that there is a yellow fever and dengue virus are prevalent among the human and vector populations in the study area. Preventive measures must be adopted to protect human beings at risk for amaril infection.

  19. Haemagogus leucocelaenus and Other Mosquitoes Potentially Associated With Sylvatic Yellow Fever In Cantareira State Park In the São Paulo Metropolitan Area, Brazil.

    PubMed

    Mucci, Luis Filipe; Medeiros-Sousa, Antônio Ralph; Ceretti-Júnior, Walter; Fernandes, Aristides; Camargo, Amanda Alves; Evangelista, Eduardo; de Oliveira Christe, Rafael; Montes, Joyce; Teixeira, Renildo Souza; Marrelli, Mauro Toledo

    2016-12-01

    The aim of this work was to investigate whether Haemagogus leucocelaenus and other mosquito species associated with sylvatic transmission of yellow fever virus are present in Cantareira State Park (CSP) in the São Paulo Metropolitan Area (SPMA). From October 2015 to March 2016, adult mosquitoes were captured with the Centers for Disease Control and Prevention traps, manual battery-powered aspirators, and Shannon traps; larvae and pupae were collected in natural and artificial breeding sites. A total of 109 adult mosquito specimens and 30 immature forms belonging to 11 taxonomic categories in 4 genera (Aedes, Psorophora, Sabethes, and Haemagogus) were collected, including Hg. leucocelaenus, the main vector of yellow fever. The entomological findings of the present study indicate that the area is of strategic importance for yellow fever surveillance not only because of the significant numbers of humans and nonhuman primates circulating in CSP and its vicinity but also because it represents a potential route for the disease to be introduced to the SPMA.

  20. [Countermeasure against viral hemorrhagic fever at the border in Japan].

    PubMed

    Iwasaki, Emiko

    2005-12-01

    Human have struggled against many infectious diseases such as cholera, plague, dysentery and yellow fever for a long time. And we have spent a lot of energy to control these infectious diseases and developed various tool for them. One of these efforts was Quarantine system that was established in 14th century in Europe. But during recent days, we are suffering from newly emerged diseases. These new infectious diseases are zoonosis and most of them are serious and highly infectious. Viral hemorrhagic fever such as Ebola hemorrhagic fever, Marburg hemorrhagic fever and Lassa fever are typical these emerging serious diseases, and these outbreak always have occurred in Africa and neighboring countries. Fortunately we have never experienced any case, but as these diseases are so serious, we are so nervous diseases entering in Japan. Against these serious diseases, in Japan, Quarantine Station are doing screening examination at airport and port by questionnaire and measuring body temperature, because these viral hemorrhagic fever patients show high fever. If people were suspected viral hemorrhagic fever at Quarantine Station at the border, they will be leaded to hospital for further examination and treatment as soon as possible.

  1. Yellow fever: ecology, epidemiology, and role in the collapse of the Classic lowland Maya civilization.

    PubMed

    Wilkinson, R L

    1995-07-01

    Mystery has long surrounded the collapse of the Classic lowland Mayan civilization of the Peten region in Guatemala. Recent population reconstructions derived from archaeological evidence from the central lowlands show population declines from urban levels of between 2.5 and 3.5 million to around 536,000 in the two hundred year interval between 800 A.D. and 1000 A.D., the period known as the Classic Maya Collapse. A steady, but lesser rate of population decline continued until the time of European contact. When knowledge of the ecology and epidemiology of yellow fever and its known mosquito vectors are compared with what is known of the ecological conditions of lowland Guatemala as modified by the Classic Maya, provocative similarities are observed. When infection and mortality patterns of more recent urban yellow fever epidemics are used as models for a possible series of Classic Maya epidemics, a correlation is noted between the modeled rate of population decline for a series of epidemics, and population decline figures reconstructed from archaeological evidence.

  2. Q Fever Outbreak among Workers at a Waste-Sorting Plant

    PubMed Central

    Alonso, Eva; Lopez-Etxaniz, Idoia; Hurtado, Ana; Liendo, Paloma; Urbaneja, Felix; Aspiritxaga, Inmaculada; Olaizola, Jose Ignacio; Piñero, Alvaro; Arrazola, Iñaki; Barandika, Jesús F.; Hernáez, Silvia; Muniozguren, Nerea; García- Pérez, Ana L.

    2015-01-01

    An outbreak of Q fever occurred in February–April 2014 among workers at a waste-sorting plant in Bilbao (Spain). The outbreak affected 58.5% of investigated employees, 47.2% as confirmed cases (PCR and/or serology) and 11.3% as probable cases (symptoms without laboratory confirmation). Only employees who had no-access to the waste processing areas of the plant were not affected and incidence of infection was significantly higher among workers not using respiratory protection masks. Detection by qPCR of Coxiella burnetii in dust collected from surfaces of the plant facilities confirmed exposure of workers inside the plant. Animal remains sporadically detected among the residues received for waste-sorting were the most probable source of infection. After cleaning and disinfection, all environmental samples tested negative. Personal protection measures were reinforced and made compulsory for the staff and actions were taken to raise farmers’ awareness of the biological risk of discharging animal carcasses as urban waste. PMID:26398249

  3. Gustatory receptor neuron responds to DEET and other insect repellents in the yellow fever mosquito, aedes aegypti

    USDA-ARS?s Scientific Manuscript database

    Three gustatory receptor neurons were characterized for contact chemoreceptive sensilla on the labella of female yellow fever mosquitoes, Aedes aegypti. The neuron with the smallest amplitude spike responded to the feeding deterrent, quinine, as well as DEET and other insect repellents. Two other ...

  4. Randomized, double-blind, multicenter study of the immunogenicity and reactogenicity of 17DD and WHO 17D-213/77 yellow fever vaccines in children: implications for the Brazilian National Immunization Program.

    PubMed

    2007-04-20

    Vaccines against yellow fever currently recommended by the World Health Organization contain either virus sub-strains 17D or 17DD. In adults, the 17DD vaccine demonstrated high seroconversion and similar performance to vaccines manufactured with the WHO 17D-213/77 seed-lot. In another study, 17DD vaccine showed lower seroconversion rates in children younger than 2 years. Data also suggested lower seroconversion with simultaneous application of measles vaccine. This finding in very young children is not consistent with data from studies with 17D vaccines. A multicenter, randomized, double-blind clinical trial was designed (1) to compare the immunogenicity and reactogenicity of two yellow fever vaccines: 17DD (licensed product) and 17D-213/77 (investigational product) in children aged 9-23 months; (2) to assess the effect of simultaneous administration of yellow fever and the measles-mumps-rubella vaccines; and (3) to investigate the interference of maternal antibodies in the response to yellow fever vaccination. The anticipated implications of the results are changes in vaccine sub-strains used in manufacturing YF vaccine used in several countries and changes in the yellow fever vaccination schedule recommendations in national immunization programs.

  5. Typhus, yellow fever and Medicine in Mexico during the French intervention

    PubMed

    Gerardo-Ramírez, Monserrat; Zavaleta-Castro, Jesús; Gómez-Quiroz, Luis Enrique

    2018-01-01

    French intervention in Mexico (1861-1867) is particularly full of episodes of patriotic heroism in terms of military, politic and, even, religious affairs, however this history is also rich in episodes related to diseases and the evolution of Mexican scientific medicine practice, epidemics such as typhus (nowadays knows as rickettsiosis), yellow fever, or cholera. Principally, this context outlined the Mexican history and influenced the course of the nation. The epidemics served as fertile land for the development of medicine science leading by prominent physicians, particularly by doctor Miguel Francisco Jiménez. Copyright: © 2018 SecretarÍa de Salud.

  6. Theories about the propagation of yellow fever: the scientific debate in the São Paulo press between 1895 and 1903.

    PubMed

    Lódola, Soraya; Góis Junior, Edivaldo

    2015-01-01

    This article describes the debate over theories about the propagation of yellow fever in the São Paulo press. Our time span was defined as the period between 1895 and 1903, a time that saw high indices of the disease in Brazil. Documentary research involved mass circulation newspapers in São Paulo and medical journals of the period. The empirical data was collected from the Public Archives of the State of São Paulo and from the library of the Faculdade de Saúde Pública at Universidade de São Paulo. It was observed a clash between theories as to the propagation of yellow fever that revealed a symbolic dispute for influence in the formation of the scientific field.

  7. Epidemiologic and clinical aspects of a Rift Valley fever outbreak in humans in Tanzania, 2007.

    PubMed

    Mohamed, Mohamed; Mosha, Fausta; Mghamba, Janeth; Zaki, Sherif R; Shieh, Wun-Ju; Paweska, Janusz; Omulo, Sylvia; Gikundi, Solomon; Mmbuji, Peter; Bloland, Peter; Zeidner, Nordin; Kalinga, Raphael; Breiman, Robert F; Njenga, M Kariuki

    2010-08-01

    In January 2007, an outbreak of Rift Valley fever (RVF) was detected among humans in northern Tanzania districts. By the end of the outbreak in June, 2007, 511 suspect RVF cases had been recorded from 10 of the 21 regions of Tanzania, with laboratory confirmation of 186 cases and another 123 probable cases. All confirmed RVF cases were located in the north-central and southern regions of the country, with an eventual fatality rate of 28.2% (N = 144). All suspected cases had fever; 89% had encephalopathy, 10% hemorrhage, and 3% retinopathy. A total of 169 (55%) of the 309 confirmed or probable cases were also positive for malaria as detected by peripheral blood smear. In a cohort of 20 RVF cases with known outcome that were also positive for human immunodeficiency virus, 15 (75%) died. Contact with sick animals and animal products, including blood, meat, and milk, were identified as major risk factors of acquiring RVF.

  8. Epidemiologic and Clinical Aspects of a Rift Valley Fever Outbreak in Humans in Tanzania, 2007

    PubMed Central

    Mohamed, Mohamed; Mosha, Fausta; Mghamba, Janeth; Zaki, Sherif R.; Shieh, Wun-Ju; Paweska, Janusz; Omulo, Sylvia; Gikundi, Solomon; Mmbuji, Peter; Bloland, Peter; Zeidner, Nordin; Kalinga, Raphael; Breiman, Robert F.; Njenga, M. Kariuki

    2010-01-01

    In January 2007, an outbreak of Rift Valley fever (RVF) was detected among humans in northern Tanzania districts. By the end of the outbreak in June, 2007, 511 suspect RVF cases had been recorded from 10 of the 21 regions of Tanzania, with laboratory confirmation of 186 cases and another 123 probable cases. All confirmed RVF cases were located in the north-central and southern regions of the country, with an eventual fatality rate of 28.2% (N = 144). All suspected cases had fever; 89% had encephalopathy, 10% hemorrhage, and 3% retinopathy. A total of 169 (55%) of the 309 confirmed or probable cases were also positive for malaria as detected by peripheral blood smear. In a cohort of 20 RVF cases with known outcome that were also positive for human immunodeficiency virus, 15 (75%) died. Contact with sick animals and animal products, including blood, meat, and milk, were identified as major risk factors of acquiring RVF. PMID:20682902

  9. Samuel Holden Parsons Lee (1772-1863): American physician, entrepreneur and selfless fighter of the 1798 Yellow Fever epidemic of New London, Connecticut.

    PubMed

    Mattie, James K; Desai, Sukumar P

    2015-02-01

    Samuel Holden Parsons Lee practised medicine at a time when the germ theory of disease had not yet been proposed and antibiotics remained undiscovered. In 1798 he served selflessly as the only physician in town who was willing to battle the Yellow Fever outbreak of New London, Connecticut. Because he practised at the dawn of the age of patent medicine, unfortunately his name also came to be associated with medical quackery. We argue that his contributions have been grossly underestimated. He compounded and vended medications - including bilious pills and bitters - that were gold standards of the day. Moreover, one preparation for treatment of kidney stones led to his sub-specialization in this field and was met with such success that its sale continued for nearly 100 years after his death. While a talented medical man, Lee also had a knack for business, finding success in trading, whaling and real estate. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  10. Standards of yellow fever vaccination and travel medicine practice in the Republic of Ireland: A questionnaire-based evaluation.

    PubMed

    Noone, Peter; Hamza, Mohammed; Tang, John; Flaherty, Gerard

    2015-01-01

    The Department of Health regulates the designation of yellow fever vaccination centres (YFVCs) in the Republic of Ireland to ensure appropriate standards in the safe, effective use of yellow fever vaccine for overseas travellers. The process of designation of YFVCs is delegated to Directors of Public Health who direct Principal Medical Officers. Variation in implementation of specific criteria for designation exists and no formal follow up inspection is carried out. This survey of all designated YFVCs in the Republic of Ireland aimed to assess compliance with standards to ensure the objectives of the national yellow fever vaccination programme were met. A piloted questionnaire devised from a United Kingdom (UK) YFVC survey was developed and tested in five YFVCs. The questionnaire was adapted for the postal survey and captured data on professional training, reference sources, services provided, physical facilities and supplies, and was distributed to 655 YFVCs in a stamped addressed envelope. During the period 2010-2011, there were 655 designated YFVCs in the Republic of Ireland. Responses were received from 246 centres (38% response rate), 91% of which were in general practice. Deficiencies were identified in respect of vaccine refrigeration protocols, record keeping, attendance at YFVC training sessions, and clinical protocols for adverse events. Specific deficiencies in relation to training, vaccine storage, administration and documentation should be addressed to ensure standardised YFVC practices and thus align them with best international practice. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Neutralizing Antibody Response to Booster Vaccination with the 17d Yellow Fever Vaccine

    DTIC Science & Technology

    2006-01-18

    FY03-28, approved 18 December 2003). 2.2. PRNT Patient sera were tested for neutralizing antibody to yellow fever virus ( YFV ) using a PRNT80 as...described by Man- giafico et al. [16], but modified for use with the Asibi strain of YFV . Briefly, test sera and controls were initially diluted 1:10 in...the 1:10 dilution, in HBSS containing human serum albumin, HEPES, peni- cillin and streptomycin. An equal volume of YFV , calculated to yield

  12. Immunogenicity and tolerability of yellow fever vaccination in 23 French HIV-infected patients.

    PubMed

    Pistone, Thierry; Verdière, Claire-Hélène; Receveur, Marie-Catherine; Ezzedine, Khaled; Lafon, Marie-Edith; Malvy, Denis

    2010-09-01

    Vaccination of asymptomatic human immunodeficiency virus (HIV)-infected patients with a CD4 cell count ≥ 200/mm³ is strongly suggested prior to travel to a region where yellow fever (YF) is endemic. However, few data describing YF vaccination in such patients are available. In this retrospective observational study of 23 HIV-infected patients, YF antibody titers, CD4 cell counts, and viral loads were measured before and after vaccination. Serologies were performed retrospectively on samples that had been stored as part of routine hospital procedures. Ninety-three percent of patients (13/14) with no baseline immunity, seroconverted after vaccination. Immunogenicity appeared slowly; only 2 of the 5 patients tested within 5 weeks of vaccination had seroconverted. A booster effect was noted in 3 of the 9 patients with baseline immunogenicity. Finally, due to unawareness of his HIV status, one patient was vaccinated and was found later to have a CD4 cell count < 200/mm³.The YF vaccine was well tolerated and no serious adverse events were reported. The impact of vaccination on immunologic and viral parameters was variable. Both decreases (n = 7) and increases (n = 5) in CD4 cell counts were recorded. Viral loads became undetectable in 2 patients and doubled or became positive in 3 patients. Yellow fever vaccination was safe and effective in a large majority of this cohort of stable, HIV-infected patients.

  13. Reemergence of yellow fever: detection of transmission in the State of São Paulo, Brazil, 2008.

    PubMed

    Moreno, Eduardo Stramandinoli; Rocco, Iray Maria; Bergo, Eduardo Sterlino; Brasil, Roosecelis Araujo; Siciliano, Melissa Mascheratti; Suzuki, Akemi; Silveira, Vivian Regina; Bisordi, Ivani; Souza, Renato Pereira de

    2011-01-01

    Following yellow fever virus (YFV) isolation in monkeys from the São José do Rio Preto region and two fatal human autochthonous cases from the Ribeirão Preto region, State of São Paulo, Brazil, two expeditions for entomological research and eco-epidemiological evaluation were conducted. A total of 577 samples from humans, 108 from monkeys and 3,049 mosquitoes were analyzed by one or more methods: virus isolation, ELISA-IgM, RT-PCR, histopathology and immunohistochemical. Of the 577 human samples, 531 were tested by ELISA-IgM, with 3 positives, and 235 were inoculated into mice and 199 in cell culture, resulting in one virus isolation. One sample was positive by histopathology and immunohistochemical. Using RT-PCR, 25 samples were processed with 4 positive reactions. A total of 108 specimens of monkeys were examined, 108 were inoculated into mice and 45 in cell culture. Four virus strains were isolated from Alouatta caraya. A total of 931 mosquitoes were captured in Sao Jose do Rio Preto and 2,118 in Ribeirão Preto and separated into batches. A single isolation of YFV was derived from a batch of 9 mosquitoes Psorophora ferox, collected in Urupês, Ribeirão Preto region. A serological survey was conducted with 128 samples from the municipalities of São Carlos, Rincão and Ribeirão Preto and 10 samples from contacts of patients from Ribeirão Preto. All samples were negative by ELISA-IgM for YFV. The results confirm the circulation of yellow fever, even though sporadic, in the Sao Paulo State and reinforce the importance of vaccination against yellow fever in areas considered at risk.

  14. Assessment of water, sanitation and hygiene interventions in response to an outbreak of typhoid fever in Neno District, Malawi.

    PubMed

    Bennett, Sarah D; Lowther, Sara A; Chingoli, Felix; Chilima, Benson; Kabuluzi, Storn; Ayers, Tracy L; Warne, Thomas A; Mintz, Eric

    2018-01-01

    On May 2, 2009 an outbreak of typhoid fever began in rural villages along the Malawi-Mozambique border resulting in 748 illnesses and 44 deaths by September 2010. Despite numerous interventions, including distribution of WaterGuard (WG) for in-home water treatment and education on its use, cases of typhoid fever continued. To inform response activities during the ongoing Typhoid outbreak information on knowledge, attitudes, and practices surrounding typhoid fever, safe water, and hygiene were necessary to plan future outbreak interventions. In September 2010, a survey was administered to female heads in randomly selected households in 17 villages in Neno District, Malawi. Stored household drinking water was tested for free chlorine residual (FCR) levels using the N,N diethyl-p-phenylene diamine colorimetric method (HACH Company, Loveland, CO, USA). Attendance at community-wide educational meetings was reported by 56% of household respondents. Respondents reported that typhoid fever is caused by poor hygiene (77%), drinking unsafe water (49%), and consuming unsafe food (25%), and that treating drinking water can prevent it (68%). WaterGuard, a chlorination solution for drinking water treatment, was observed in 112 (56%) households, among which 34% reported treating drinking water. FCR levels were adequate (FCR ≥ 0.2 mg/L) in 29 (76%) of the 38 households who reported treatment of stored water and had stored water available for testing and an observed bottle of WaterGuard in the home. Soap was observed in 154 (77%) households, among which 51% reported using soap for hand washing. Educational interventions did not reach almost one-half of target households and knowledge remains low. Despite distribution and promotion of WaterGuard and soap during the outbreak response, usage was low. Future interventions should focus on improving water, sanitation and hygiene knowledge, practices, and infrastructure. Typhoid vaccination should be considered.

  15. Assessment of water, sanitation and hygiene interventions in response to an outbreak of typhoid fever in Neno District, Malawi

    PubMed Central

    Lowther, Sara A.; Chingoli, Felix; Chilima, Benson; Kabuluzi, Storn; Ayers, Tracy L.; Warne, Thomas A.; Mintz, Eric

    2018-01-01

    On May 2, 2009 an outbreak of typhoid fever began in rural villages along the Malawi-Mozambique border resulting in 748 illnesses and 44 deaths by September 2010. Despite numerous interventions, including distribution of WaterGuard (WG) for in-home water treatment and education on its use, cases of typhoid fever continued. To inform response activities during the ongoing Typhoid outbreak information on knowledge, attitudes, and practices surrounding typhoid fever, safe water, and hygiene were necessary to plan future outbreak interventions. In September 2010, a survey was administered to female heads in randomly selected households in 17 villages in Neno District, Malawi. Stored household drinking water was tested for free chlorine residual (FCR) levels using the N,N diethyl-p-phenylene diamine colorimetric method (HACH Company, Loveland, CO, USA). Attendance at community-wide educational meetings was reported by 56% of household respondents. Respondents reported that typhoid fever is caused by poor hygiene (77%), drinking unsafe water (49%), and consuming unsafe food (25%), and that treating drinking water can prevent it (68%). WaterGuard, a chlorination solution for drinking water treatment, was observed in 112 (56%) households, among which 34% reported treating drinking water. FCR levels were adequate (FCR ≥ 0.2 mg/L) in 29 (76%) of the 38 households who reported treatment of stored water and had stored water available for testing and an observed bottle of WaterGuard in the home. Soap was observed in 154 (77%) households, among which 51% reported using soap for hand washing. Educational interventions did not reach almost one-half of target households and knowledge remains low. Despite distribution and promotion of WaterGuard and soap during the outbreak response, usage was low. Future interventions should focus on improving water, sanitation and hygiene knowledge, practices, and infrastructure. Typhoid vaccination should be considered. PMID:29474394

  16. Nationwide registry-based ecological analysis of Q fever incidence and pregnancy outcome during an outbreak in the Netherlands

    PubMed Central

    de Lange, Marit M A; Hukkelhoven, Chantal W P M; Munster, Janna M; Schneeberger, Peter M; van der Hoek, Wim

    2015-01-01

    Objective Whether areas affected by Q fever during a large outbreak (2008–2010) had higher rates of adverse pregnancy outcomes than areas not affected by Q fever. Design Nationwide registry-based ecological study. Setting Pregnant women in areas affected and not affected by Q fever in the Netherlands, 2003–2004 and 2008–2010. Participants Index group (N=58 737): pregnant women in 307 areas with more than two Q fever notifications. Reference group (N=310 635): pregnant women in 921 areas without Q fever notifications. As a baseline, pregnant women in index and reference areas in the years 2003–2004 were also included in the reference group to estimate the effect of Q fever in 2008–2010, and not the already existing differences before the outbreak. Main outcome measures Preterm delivery, small for gestational age, perinatal mortality. Results In 2008–2010, there was no association between residing in a Q fever-affected area and both preterm delivery (adjusted OR 1.01 (95% CI 0.94 to 1.08)), and perinatal mortality (adjusted OR 0.87 (95% CI 0.72 to 1.05)). In contrast, we found a weak significant association between residing in a Q fever-affected area in 2008–2010 and small for gestational age (adjusted OR 1.06 (95% CI 1.01 to 1.12)), with a population-attributable fraction of 0.70% (95% CI 0.07% to 1.34%). We observed no dose–response relation for this outcome with increasing Q fever notifications, and we did not find a stronger association for women who were in their first trimester of pregnancy during the months of high human Q fever incidence. Conclusions This study found a weak association between residing in a Q fever-affected area and the pregnancy outcome small for gestational age. Early detection of infection would require mass screening of pregnant women; this does not seem to be justified considering these results, and the uncertainties about its efficacy and the adverse effects of antibiotic treatment. PMID:25862010

  17. Epidemiological trends and the effect of airport fever screening on prevention of domestic dengue fever outbreaks in Taiwan, 1998-2007.

    PubMed

    Kuan, Mei-Mei; Lin, Ting; Chuang, Jen-Hsiang; Wu, Ho-Sheng

    2010-08-01

    This study aimed to examine the epidemiological trends in dengue infection and the impact of imported cases and airport fever screening on community transmission in Taiwan, a dengue non-endemic island. All of the dengue case data were obtained from the surveillance system of the Taiwan Center for Disease Control and were analyzed by Pearson correlations, linear regression, and geographical information system (GIS)-based mapping. The impact of implementing airport fever screening was evaluated using the Student's t-test and two-way analysis of variance. A total of 10 351 dengue cases, including 7.1% of imported cases were investigated between 1998 and 2007. The majority of indigenous dengue cases (98.5%) were significantly clustered in southern Taiwan; 62.9% occurred in the metropolitan areas. The seasonality of dengue cases showed a peak from September to November. Airport fever screening was successful in identifying 45% (244/542 ; 95% confidence interval 33.1-57.8%) of imported dengue cases with fever. However, no statistical difference was found regarding the impact on community transmission when comparing the presence and absence of airport fever screening. Our results show that airport fever screening had a positive effect on partially blocking the local transmission of imported dengue cases, while those undetected cases due to latent or asymptomatic infection would be the source of new dengue outbreaks each year. Copyright © 2010 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  18. Impact of Global Climate on Rift Valley Fever and other Vector-borne Disease Outbreaks

    NASA Astrophysics Data System (ADS)

    Linthicum, K. J.

    2017-12-01

    Rift Valley fever is a viral disease of animals and humans in Africa and the Middle East that is transmitted by mosquitoes. Since the virus was first isolated in Kenya in 1930 it has caused significant impact to animal and human health and national economies, and it is of concern to the international agricultural and public health community. In this presentation we will describe the (1) ecology of disease transmission as it relates to climate, (2) the impact of climate and other environmental conditions on outbreaks, (3) the ability to use global climate information to predict outbreaks, (4) effective response activities, and (4) the potential to mitigate globalization.

  19. A dynamic case definition is warranted for adequate notification in an extended epidemic setting: the Dutch Q fever outbreak 2007-2009 as exemplar.

    PubMed

    Jaramillo-Gutierrez, G; Wegdam-Blans, M C; ter Schegget, R; Korbeeck, J M; van Aken, R; Bijlmer, H A; Tjhie, J H; Koopmans, M P

    2013-10-10

    Q fever is a notifiable disease in the Netherlands:laboratories are obliged to notify possible cases to the Municipal Health Services. These services then try to reconfirm cases with additional clinical and epidemiological data and provide anonymised reports to the national case register of notifiable diseases. Since the start of the 2007–2009 Dutch Q fever outbreak,notification rules remained unchanged, despite new laboratory insights and altered epidemiology. In this study, we retrospectively analysed how these changes influenced the proportion of laboratory-defined acute Q fever cases (confirmed, probable and possible)that were included in the national case register, during(2009) and after the outbreak (2010 and 2011).The number of laboratory-defined cases notified to the Municipal Health Services was 377 in 2009, 96 in 2010 and 50 in 2011. Of these, 186 (49.3%) in 2009, 12(12.5%) in 2010 and 9 (18.0%) in 2011 were confirmed as acute infection by laboratory interpretation. The proportion of laboratory-defined acute Q fever cases that was reconfirmed by the Municipal Health Services and that were included in the national case register decreased from 90% in 2009, to 22% and 24% in 2010 and 2011, respectively. The decrease was observed in all categories of cases, including those considered to be confirmed by laboratory criteria. Continued use ofa pre-outbreak case definition led to over-reporting of cases to the Municipal Health Services in the post-epidemic years. Therefore we recommend dynamic laboratory notification rules, by reviewing case definitions periodically in an ongoing epidemic, as in the Dutch Q fever outbreak.

  20. IMOJEV(®): a Yellow fever virus-based novel Japanese encephalitis vaccine.

    PubMed

    Appaiahgari, Mohan Babu; Vrati, Sudhanshu

    2010-12-01

    Japanese encephalitis (JE) is a disease of the CNS caused by Japanese encephalitis virus (JEV). The disease appears in the form of frequent outbreaks in most south- and southeast Asian countries and the virus has become endemic in several areas. There is no licensed therapy available and disease control by vaccination is considered to be most effective. Mouse brain-derived inactivated JE vaccines, although immunogenic, have several limitations in terms of safety, availability and requirement for multiple doses. Owing to these drawbacks, the WHO called for the development of novel, safe and more efficacious JE vaccines. Several candidate vaccines have been developed and at least three of them that demonstrated strong immunogenicity after one or two doses of the vaccine in animal models were subsequently tested in various clinical trials. One of these vaccines, IMOJEV(®) (JE-CV and previously known as ChimeriVax™-JE), is a novel recombinant chimeric virus vaccine, developed using the Yellow fever virus (YFV) vaccine vector YFV17D, by replacing the cDNA encoding the envelope proteins of YFV with that of an attenuated JEV strain SA14-14-2. IMOJEV was found to be safe, highly immunogenic and capable of inducing long-lasting immunity in both preclinical and clinical trials. Moreover, a single dose of IMOJEV was sufficient to induce protective immunity, which was similar to that induced in adults by three doses of JE-VAX(®), a mouse brain-derived inactivated JE vaccine. Recently, Phase III trials evaluating the immunogenicity and safety of the chimeric virus vaccine have been successfully completed in some JE-endemic countries and the vaccine manufacturers have filed an application for vaccine registration. IMOJEV may thus be licensed for use in humans as an improved alternative to the currently licensed JE vaccines.

  1. Hemorrhagic Fevers

    MedlinePlus

    ... by four families of viruses. These include the Ebola and Marburg, Lassa fever, and yellow fever viruses. ... Some VHFs cause mild disease, but some, like Ebola or Marburg, cause severe disease and death. VHFs ...

  2. Classical Swine Fever Outbreak after Modified Live LOM Strain Vaccination in Naive Pigs, South Korea

    PubMed Central

    Je, Sang H.; Kwon, Taeyong; Yoo, Sung J.; Lee, Dong-Uk; Lee, SeungYoon; Richt, Juergen A.

    2018-01-01

    We report classical swine fever outbreaks occurring in naive pig herds on Jeju Island, South Korea, after the introduction of the LOM vaccine strain. Two isolates from sick pigs had >99% identity with the vaccine stain. LOM strain does not appear safe; its use in the vaccine should be reconsidered. PMID:29553332

  3. Genetic Divergence and Dispersal of Yellow Fever Virus, Brazil

    PubMed Central

    Bryant, Juliet E.; Travassos da Rosa, Amelia P.A.; Tesh, Robert B.; Rodrigues, Sueli G.; Barrett, Alan D.T.

    2004-01-01

    An analysis of 79 yellow fever virus (YFV) isolates collected from 1935 to 2001 in Brazil showed a single genotype (South America I) circulating in the country, with the exception of a single strain from Rondônia, which represented South America genotype II. Brazilian YFV strains have diverged into two clades; an older clade appears to have become extinct and another has become the dominant lineage in recent years. Pairwise nucleotide diversity between strains ranged from 0% to 7.4%, while amino acid divergence ranged from 0% to 4.6%. Phylogenetic analysis indicated traffic of virus variants through large geographic areas and suggested that migration of infected people may be an important mechanism of virus dispersal. Isolation of vaccine virus from a patient with a fatal case suggests that vaccine-related illness may have been misdiagnosed in the past. PMID:15498159

  4. [Enzyme-linked immunosorbent assay (ELISA) for detection of antibodies to Salmonella Typhi lipopolysaccharide O and capsular polysaccharide Vi antigens in persons from outbreak of typhoid fever].

    PubMed

    Rastawicki, Waldemar; Kałużewski, Stanisław

    2015-01-01

    The laboratory diagnosis of typhoid fever is dependent upon either isolation of S. Typhi from a clinical sample or the detection of raised titers of serum antibodies in the Widal test or the passive hemagglutination assay (PHA). In this study we evaluated the usefulness of ELISA for detection of antibodies to S. Typhi lipopolysaccharide O and capsular polysaccharide Vi antigens in the sera of persons from outbreak of typhoid fever. Fifteen serum samples from patients with laboratory confirmed typhoid fever and 140 sera from persons suspected for contact with typhoid fever patients from outbreak in 1974/75 in Poland were tested by ELISA. Additionally, as the control group, we tested 115 sera from blood donors for the presence of S. Typhi anti-LPS and anti-Vi antibodies. Anti-LPS and anti-Vi antibodies were detected in 80% and 53.3% of sera obtained from patients with laboratory confirmed typhoid fever, respectively. The high percentages of positive results in ELISA were also noted in the group of persons suspected for contact with typhoid fever patients (51.4% and 45%) but not in the group of blood donors (7.8% and 6.1%, respectively). The ELISA could be a useful tool for the serological diagnosis of typhoid fever in patients who have clinical symptoms but are culture negative, especially during massive outbreaks of typhoid fever.

  5. Toxicity of compounds isolated from white snakeroot (Ageratina altissima) to adult and larval yellow fever mosquitoes (Aedes aegypti)

    USDA-ARS?s Scientific Manuscript database

    Because of increasing insecticide resistance, new pesticides are needed. Flowering plants have been the source of useful pesticides in the past. We studied 15 chemicals isolated from a poisonous pasture plant for activity against the yellow fever mosquito. We found that dehydrotremetone was effectiv...

  6. Efficacy of 2'-C-methylcytidine against yellow fever virus in cell culture and in a hamster model.

    PubMed

    Julander, Justin G; Jha, Ashok K; Choi, Jung-Ae; Jung, Kie-Hoon; Smee, Donald F; Morrey, John D; Chu, Chung K

    2010-06-01

    Yellow fever virus (YFV) continues to cause outbreaks of disease in endemic areas where vaccine is underutilized. Due to the effectiveness of the vaccine, antiviral development solely for the treatment of YFV is not feasible, but antivirals that are effective in the treatment of related viral diseases may be characterized for potential use against YFV as a secondary indication disease. 2'-C-methylcytidine (2'-C-MeC), a compound active against hepatitis C virus, was found to have activity against the 17D vaccine strain of YFV in cell culture (EC(90)=0.32 microg/ml, SI=141). This compound was effective when added as late as 16 h after virus challenge of Vero cells. When administered to YFV-infected hamsters 4 h prior to virus challenge at a dose as low as 80 mg/kg/d, 2'-C-MeC was effective in significantly improving survival and other disease parameters (weight change, serum ALT, and liver virus titers). Disease was improved when compound was administered beginning as late as 3 d post-virus infection. Broadly active antiviral compounds, such as 2'-C-MeC, represent potential for the development of compounds active against related viruses for the treatment of YFV. Copyright 2010 Elsevier B.V. All rights reserved.

  7. Newly discovered ebola virus associated with hemorrhagic fever outbreak in Uganda.

    PubMed

    Towner, Jonathan S; Sealy, Tara K; Khristova, Marina L; Albariño, César G; Conlan, Sean; Reeder, Serena A; Quan, Phenix-Lan; Lipkin, W Ian; Downing, Robert; Tappero, Jordan W; Okware, Samuel; Lutwama, Julius; Bakamutumaho, Barnabas; Kayiwa, John; Comer, James A; Rollin, Pierre E; Ksiazek, Thomas G; Nichol, Stuart T

    2008-11-01

    Over the past 30 years, Zaire and Sudan ebolaviruses have been responsible for large hemorrhagic fever (HF) outbreaks with case fatalities ranging from 53% to 90%, while a third species, Côte d'Ivoire ebolavirus, caused a single non-fatal HF case. In November 2007, HF cases were reported in Bundibugyo District, Western Uganda. Laboratory investigation of the initial 29 suspect-case blood specimens by classic methods (antigen capture, IgM and IgG ELISA) and a recently developed random-primed pyrosequencing approach quickly identified this to be an Ebola HF outbreak associated with a newly discovered ebolavirus species (Bundibugyo ebolavirus) distantly related to the Côte d'Ivoire ebolavirus found in western Africa. Due to the sequence divergence of this new virus relative to all previously recognized ebolaviruses, these findings have important implications for design of future diagnostic assays to monitor Ebola HF disease in humans and animals, and ongoing efforts to develop effective antivirals and vaccines.

  8. Newly Discovered Ebola Virus Associated with Hemorrhagic Fever Outbreak in Uganda

    PubMed Central

    Towner, Jonathan S.; Sealy, Tara K.; Khristova, Marina L.; Albariño, César G.; Conlan, Sean; Reeder, Serena A.; Quan, Phenix-Lan; Lipkin, W. Ian; Downing, Robert; Tappero, Jordan W.; Okware, Samuel; Lutwama, Julius; Bakamutumaho, Barnabas; Kayiwa, John; Comer, James A.; Rollin, Pierre E.; Ksiazek, Thomas G.; Nichol, Stuart T.

    2008-01-01

    Over the past 30 years, Zaire and Sudan ebolaviruses have been responsible for large hemorrhagic fever (HF) outbreaks with case fatalities ranging from 53% to 90%, while a third species, Côte d'Ivoire ebolavirus, caused a single non-fatal HF case. In November 2007, HF cases were reported in Bundibugyo District, Western Uganda. Laboratory investigation of the initial 29 suspect-case blood specimens by classic methods (antigen capture, IgM and IgG ELISA) and a recently developed random-primed pyrosequencing approach quickly identified this to be an Ebola HF outbreak associated with a newly discovered ebolavirus species (Bundibugyo ebolavirus) distantly related to the Côte d'Ivoire ebolavirus found in western Africa. Due to the sequence divergence of this new virus relative to all previously recognized ebolaviruses, these findings have important implications for design of future diagnostic assays to monitor Ebola HF disease in humans and animals, and ongoing efforts to develop effective antivirals and vaccines. PMID:19023410

  9. Surface expression of an immunodominant malaria protein B cell epitope by yellow fever virus.

    PubMed

    Bonaldo, Myrna C; Garratt, Richard C; Caufour, Philippe S; Freire, Marcos S; Rodrigues, Mauricio M; Nussenzweig, Ruth S; Galler, Ricardo

    2002-01-25

    The yellow fever 17D virus (YF17D) has several characteristics that are desirable for the development of new, live attenuated vaccines. We approached its development as a vector for heterologous antigens by studying the expression of a humoral epitope at the surface of the E protein based on the results of modelling its three-dimensional structure. This model indicated that the most promising insertion site is between beta-strands f and g, a site that is exposed at the external surface of the virus. The large deletion of six residues from the fg loop of the E protein from yellow fever virus, compared to tick-born encephalitis virus, leaves space at the dimer interface for a large insertion without creating steric hindrance. We have tested this hypothesis by inserting a model humoral epitope from the circumsporozoite protein of Plasmodium falciparum consisting of triple NANP repeats. Recombinant virus (17D/8) expressing this insertion flanked by two glycine residues at each end, is specifically neutralized by a monoclonal antibody to the model epitope. Furthermore, mouse antibodies raised to the recombinant virus recognize the parasite protein in an ELISA assay. Serial passage analysis confirmed the genetic stability of the insertion made in the viral genome and the resulting 17D/8 virus is significantly more attenuated in mouse neurovirulence tests than the 17DD vaccine. The fg loop belongs to the dimerization domain of the E protein and lies at the interface between monomers. This domain undergoes a low pH transition, which is related to the fusion of the viral envelope to the endosome membrane. It is conceivable that a slower rate of fusion, resulting from the insertion close to the dimer interface, may delay the onset of virus production and thereby lead to a milder infection of the host. This would account for the more attenuated phenotype of the recombinant virus in the mouse model and lower extent of replication in cultured cells. The vectorial capacity of

  10. Development and applications of transgenesis in the yellow fever mosquito, Aedes aegypti.

    PubMed

    Adelman, Zachary N; Jasinskiene, Nijole; James, Anthony A

    2002-04-30

    Transgenesis technology has been developed for the yellow fever mosquito, Aedes aegypti. Successful integration of exogenous DNA into the germline of this mosquito has been achieved with the class II transposable elements, Hermes, mariner and piggyBac. A number of marker genes, including the cinnabar(+) gene of Drosophila melanogaster, and fluorescent protein genes, can be used to monitor the insertion of these elements. The availability of multiple elements and marker genes provides a powerful set of tools to investigate basic biological properties of this vector insect, as well as the materials for developing novel, genetics-based, control strategies for the transmission of disease.

  11. How Did the Dengue Fever Outbreak Progress in Yoyogi Park, Tokyo, in 2014?-Evaluation Based on a Mathematical Model.

    PubMed

    Ishikawa, Hirofumi; Shimogawara, Rieko; Fueda, Kaoru

    2017-01-01

    In the summer of 2014, an outbreak of autochthonous dengue fever occurred in Yoyogi Park and its vicinity, Tokyo, Japan. In this study, we investigated how the dengue fever outbreak progressed in Yoyogi Park using a mathematical model. This study was limited to the transmission of the dengue virus in Yoyogi Park and its vicinity. We estimated the distributions of the intrinsic incubation period and infection dates on the basis of epidemiological information on the dengue outbreak in 2014. We searched for an assumption that satisfactorily explains the outbreak in 2014 using rough estimates of secondary and tertiary infection cases. We constructed a mathematical model for the transmission of the dengue virus between humans and Aedes albopictus. We carried out 1,000-trial stochastic simulations for all combinations of three kinds of assumption about Ae. albopictus and asymptomatic infection with each of three levels. Simulation results showed that the scale of the outbreak was markedly affected by the daily survival rate of Ae. albopictus. The outbreak involved a small number of secondary infection cases, reached a peak at tertiary infection, and transformed to termination at the fourth infection. Under some assumptions, the daily progress of onset cases was within a range between the 1st-3rd quartiles of 1,000 trials for 87% of dates and within a range between the minimum and maximum for all dates. It is important to execute plans to detect asymptomatic cases and reduce the survival rate of Ae. albopictus to prevent the spread of tertiary infections unless an outbreak is suppressed at the secondary infection stage.

  12. Shifts in geographic distribution and antimicrobial resistance during a prolonged typhoid fever outbreak--Bundibugyo and Kasese Districts, Uganda, 2009-2011.

    PubMed

    Walters, Maroya Spalding; Routh, Janell; Mikoleit, Matthew; Kadivane, Samuel; Ouma, Caroline; Mubiru, Denis; Mbusa, Ben; Murangi, Amos; Ejoku, Emmanuel; Rwantangle, Absalom; Kule, Uziah; Lule, John; Garrett, Nancy; Halpin, Jessica; Maxwell, Nikki; Kagirita, Atek; Mulabya, Fred; Makumbi, Issa; Freeman, Molly; Joyce, Kevin; Hill, Vince; Downing, Robert; Mintz, Eric

    2014-03-01

    Salmonella enterica serovar Typhi is transmitted by fecally contaminated food and water and causes approximately 22 million typhoid fever infections worldwide each year. Most cases occur in developing countries, where approximately 4% of patients develop intestinal perforation (IP). In Kasese District, Uganda, a typhoid fever outbreak notable for a high IP rate began in 2008. We report that this outbreak continued through 2011, when it spread to the neighboring district of Bundibugyo. A suspected typhoid fever case was defined as IP or symptoms of fever, abdominal pain, and ≥1 of the following: gastrointestinal disruptions, body weakness, joint pain, headache, clinically suspected IP, or non-responsiveness to antimalarial medications. Cases were identified retrospectively via medical record reviews and prospectively through laboratory-enhanced case finding. Among Kasese residents, 709 cases were identified from August 1, 2009-December 31, 2011; of these, 149 were identified during the prospective period beginning November 1, 2011. Among Bundibugyo residents, 333 cases were identified from January 1-December 31, 2011, including 128 cases identified during the prospective period beginning October 28, 2011. IP was reported for 507 (82%) and 59 (20%) of Kasese and Bundibugyo cases, respectively. Blood and stool cultures performed for 154 patients during the prospective period yielded isolates from 24 (16%) patients. Three pulsed-field gel electrophoresis pattern combinations, including one observed in a Kasese isolate in 2009, were shared among Kasese and Bundibugyo isolates. Antimicrobial susceptibility was assessed for 18 isolates; among these 15 (83%) were multidrug-resistant (MDR), compared to 5% of 2009 isolates. Molecular and epidemiological evidence suggest that during a prolonged outbreak, typhoid spread from Kasese to Bundibugyo. MDR strains became prevalent. Lasting interventions, such as typhoid vaccination and improvements in drinking water infrastructure

  13. Genetic stability of a dengue vaccine based on chimeric yellow fever/dengue viruses.

    PubMed

    Mantel, N; Girerd, Y; Geny, C; Bernard, I; Pontvianne, J; Lang, J; Barban, V

    2011-09-02

    A tetravalent dengue vaccine based on four live, attenuated, chimeric viruses (CYD1-4), constructed by replacing the genes coding for premembrane (prM) and envelope (E) proteins of the yellow fever (YF)-17D vaccine strain with those of the four serotypes of dengue virus, is in clinical phase III evaluation. We assessed the vaccine's genetic stability by fully sequencing each vaccine virus throughout the development and manufacturing process. The four viruses displayed complete genetic stability, with no change from premaster seed lots to bulk lots. When pursuing the virus growth beyond bulk lots, a few genetic variations were observed. Usually both the initial nucleotide and the new one persisted, and mutations appeared after a relatively high number of virus duplication cycles (65-200, depending on position). Variations were concentrated in the prM-E and non-structural (NS)4B regions. PrM-E variations had no impact on lysis-plaque size or neurovirulence in mice. None of the variations located in the YF-17D-derived genes corresponded with reversion to the wild-type Yellow Fever sequence. Variations in NS4B likely reflect virus adaptation to Vero cells growth. A low to undetectable viremia has been reported previously [1-3] in vaccinated non-human and human primates. Combined with the data reported here about the genetic stability of the vaccine strains, the probability of in vivo emergence of mutant viruses appears very low. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Dead or alive: animal sampling during Ebola hemorrhagic fever outbreaks in humans

    PubMed Central

    Olson, Sarah H.; Reed, Patricia; Cameron, Kenneth N.; Ssebide, Benard J.; Johnson, Christine K.; Morse, Stephen S.; Karesh, William B.; Mazet, Jonna A. K.; Joly, Damien O.

    2012-01-01

    There are currently no widely accepted animal surveillance guidelines for human Ebola hemorrhagic fever (EHF) outbreak investigations to identify potential sources of Ebolavirus (EBOV) spillover into humans and other animals. Animal field surveillance during and following an outbreak has several purposes, from helping identify the specific animal source of a human case to guiding control activities by describing the spatial and temporal distribution of wild circulating EBOV, informing public health efforts, and contributing to broader EHF research questions. Since 1976, researchers have sampled over 10,000 individual vertebrates from areas associated with human EHF outbreaks and tested for EBOV or antibodies. Using field surveillance data associated with EHF outbreaks, this review provides guidance on animal sampling for resource-limited outbreak situations, target species, and in some cases which diagnostics should be prioritized to rapidly assess the presence of EBOV in animal reservoirs. In brief, EBOV detection was 32.7% (18/55) for carcasses (animals found dead) and 0.2% (13/5309) for live captured animals. Our review indicates that for the purposes of identifying potential sources of transmission from animals to humans and isolating suspected virus in an animal in outbreak situations, (1) surveillance of free-ranging non-human primate mortality and morbidity should be a priority, (2) any wildlife morbidity or mortality events should be investigated and may hold the most promise for locating virus or viral genome sequences, (3) surveillance of some bat species is worthwhile to isolate and detect evidence of exposure, and (4) morbidity, mortality, and serology studies of domestic animals should prioritize dogs and pigs and include testing for virus and previous exposure. PMID:22558004

  15. Early molecular correlates of adverse events following yellow fever vaccination

    PubMed Central

    Chan, Candice Y.Y.; Chan, Kuan Rong; Chua, Camillus J.H.; nur Hazirah, Sharifah; Ghosh, Sujoy; Ooi, Eng Eong; Low, Jenny G.

    2017-01-01

    The innate immune response shapes the development of adaptive immunity following infections and vaccination. However, it can also induce symptoms such as fever and myalgia, leading to the possibility that the molecular basis of immunogenicity and reactogenicity of vaccination are inseparably linked. To test this possibility, we used the yellow fever live-attenuated vaccine (YFLAV) as a model to study the molecular correlates of reactogenicity or adverse events (AEs). We analyzed the outcome of 68 adults who completed a YFLAV clinical trial, of which 43 (63.2%) reported systemic AEs. Through whole-genome profiling of blood collected before and after YFLAV dosing, we observed that activation of innate immune genes at day 1, but not day 3 after vaccination, was directly correlated with AEs. These findings contrast with the gene expression profile at day 3 that we and others have previously shown to be correlated with immunogenicity. We conclude that although the innate immune response is a double-edged sword, its expression that induces AEs is temporally distinct from that which engenders robust immunity. The use of genomic profiling thus provides molecular insights into the biology of AEs that potentially forms a basis for the development of safer vaccines. PMID:28978802

  16. Persistence of Yellow Fever vaccine-induced antibodies after cord blood stem cell transplant.

    PubMed

    Avelino-Silva, Vivian Iida; Freire, Marcos da Silva; Rocha, Vanderson; Rodrigues, Celso Arrais; Novis, Yana Sarkis; Sabino, Ester C; Kallas, Esper Georges

    2016-04-02

    We report the case of a cord blood haematopoietic stem cell transplant recipient who was vaccinated for Yellow Fever (YF) 7 days before initiating chemotherapy and had persistent YF antibodies more than 3 years after vaccination. Since the stem cell donor was never exposed to wild YF or to the YF vaccine, and our patient was not exposed to YF or revaccinated, this finding strongly suggests the persistence of recipient immunity. We briefly discuss potential consequences of incomplete elimination of recipient's leukocytes following existing haematopoietic cancer treatments.

  17. IMMUNOLOGICAL STUDIES WITH A STRAIN OF LEPTOSPIRA ISOLATED FROM A CASE OF YELLOW FEVER IN MERIDA, YUCATAN

    PubMed Central

    Noguchi, Hideyo; Kligler, I. J.

    1920-01-01

    Identification of the leptospira isolated from a case of yellow fever in Merida was accomplished by means of an anti-icteroides immune serum prepared in a horse with several Guayaquil strains of Leptospira icteroides. The immune serum showed a protective action of high titer against the Merida strain, thus establishing its efficacy as a therapeutic agent against this strain. Polyvalent anti-icteroides immune serum prepared in the horse or monovalent anti-icteroides immune serums prepared in the rabbit had a definite devitalizing action upon the Merida strain, while immune serums similarly prepared with strains of icterohœmorrhagiœ had no perceptible effect upon the Merida strain. Serums from yellow fever convalescents in Merida gave a positive Pfeiffer reaction with the Merida strain of Leptospira icteroides. The reactions between the Guayaquil strains (Nos. 1 and 5) and two of these serums from convalescents varied from definitely positive to doubtful, owing probably to the diminution of active immune principles in the serums during the prolonged and unfavorable conditions of their transportation. PMID:19868465

  18. Risk of yellow fever vaccine-associated viscerotropic disease among the elderly: a systematic review.

    PubMed

    Rafferty, Ellen; Duclos, Philippe; Yactayo, Sergio; Schuster, Melanie

    2013-12-02

    Yellow fever vaccine-associated viscerotropic disease (YEL-AVD) is a rare and serious adverse event of the yellow fever (YF) vaccine that mimics wild-type YF. Research shows there may be an increased risk of YEL-AVD among the elderly population (≥ 60-65 years old), however this research has yet to be accumulated and reviewed in order to make policy recommendations to countries currently administering the YF vaccine. This paper systematically reviewed all information available on YEL-AVD to determine if there is an increased risk among the elderly, for both travelers and endemic populations. Age-specific reporting rates (RRs) were re-calculated from the literature using the Brighton Collaboration case definition for YEL-AVD and were then analyzed to determine if there was a significant difference between the RRs of younger and older age groups. Two out of the five studies found a significantly higher rate of YEL-AVD among the elderly population. Our findings suggest unexposed elders may be at an increased risk of developing YEF-AVD, however the evidence remains limited. Therefore, our findings for YF vaccination of elderly populations support the recommendations made by the Strategic Advisory Group of Experts (SAGE) in their April 2013 meeting, mainly vaccination of the elderly should be based on a careful risk-benefit analysis. Copyright © 2013 World Health Organization (WHO). Published by Elsevier Ltd.. All rights reserved.

  19. Emergence of viral hemorrhagic fevers: is recent outbreak of Crimean Congo Hemorrhagic Fever in India an indication?

    PubMed

    Lahariya, C; Goel, M K; Kumar, A; Puri, M; Sodhi, A

    2012-01-01

    The emerging and re-emerging diseases are posing a great health risk for the last few years. One such category of diseases is viral haemorrhagic fevers (VHFs), which have emerged in the new territories, worldwide. Crimean Congo Hemorrhagic Fever (CCHF) cases, for the first time in India, were reported from Gujarat, in January 2011. The emergence of diseases not reported earlier, pose great economic and social challenge, burden health system, and create panic reaction. Nonetheless, with recent experience in control of epidemic diseases, and advances in basic scientific knowledge; the public health community is better prepared for these unexpected events. This review provides information to physicians on CCHF for managing outbreak, and identifies public health measures to prevent emergence and re-emergence of VHFs (including CCHF) in future. The authors suggest that though, there are a few challenging and unanswered questions, the public health preparedness still remains the key to control emerging and re-emerging diseases. The countries where virus activities have been reported need to be prepared accordingly.

  20. Comparison of the PRNT and an immune fluorescence assay in yellow fever vaccinees receiving immunosuppressive medication.

    PubMed

    Wieten, Rosanne W; Jonker, Emile F F; Pieren, Daan K J; Hodiamont, Caspar J; van Thiel, Pieter P A M; van Gorp, Eric C M; de Visser, Adriëtte W; Grobusch, Martin P; Visser, Leo G; Goorhuis, Abraham

    2016-03-04

    The 17D-yellow fever (YF) vaccination is considered contraindicated in immune-compromised patients; however, accidental vaccination occurs. In this population, measuring the immune response is useful in clinical practice. In this study we compare two antibody tests (the Immune Fluorescence Assay and the Plaque Reduction Neutralization Test) in a group of Dutch immune-compromised travellers with a median of 33 days (IQR [28-49]) after primary YF vaccination. We collected samples of 15 immune-compromised vaccinees vaccinated with the 17D yellow fever vaccine between 2004 and 2012. All samples measured in the plaque reduction neutralization test yielded positive results (>80% virus neutralization with a 1:10 serum dilution). Immune Fluorescence Assay sensitivity was 28% (95% CI [0.12-0.49]). No adverse events were reported. All immune-compromised patients mounted an adequate response with protective levels of virus neutralizing antibodies to the 17-D YF vaccine. No adverse effects were reported. Compared to the plaque reduction neutralization test, the sensitivity of the Immune Fluorescence Assay test was low. Further research is needed to ascertain that 17D vaccination in immune-compromised patients is safe. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Adaptive Diversification Between Yellow Fever Virus West African and South American Lineages: A Genome-Wide Study.

    PubMed

    Li, Yan; Yang, Zexiao

    2017-03-01

    AbstractYellow fever virus (YFV) has emerged as the causative agent of a vector-borne disease with devastating mortality in the tropics of Africa and the Americas. YFV phylogenies indicate that the isolates collected from West Africa, East and Central Africa, and South America cluster into different lineages and the virus spread into the Americas from Africa. To determine the nature of genetic variation accompanying the intercontinental epidemic, we performed a genome-wide evolutionary study on the West African and South American lineages of YFV. Our results reveal that adaptive genetic diversification has occurred on viral nonstructural protein 5 (NS5), which is crucially required for viral genome replication, in the early epidemic phase of these currently circulating lineages. Furthermore, major amino acid changes relevant to the adaptive diversification generally cluster in different structural regions of NS5 in a lineage-specific manner. These results suggest that YFV has experienced adaptive diversification in the epidemic spread between the continents and shed insights into the genetic determinants of such diversification, which might be beneficial for understanding the emergence and re-emergence of yellow fever as an important global public health issue.

  2. The use of a geographic information system to identify a dairy goat farm as the most likely source of an urban Q-fever outbreak.

    PubMed

    Schimmer, Barbara; Ter Schegget, Ronald; Wegdam, Marjolijn; Züchner, Lothar; de Bruin, Arnout; Schneeberger, Peter M; Veenstra, Thijs; Vellema, Piet; van der Hoek, Wim

    2010-03-16

    A Q-fever outbreak occurred in an urban area in the south of the Netherlands in May 2008. The distribution and timing of cases suggested a common source. We studied the spatial relationship between the residence locations of human cases and nearby small ruminant farms, of which one dairy goat farm had experienced abortions due to Q-fever since mid April 2008. A generic geographic information system (GIS) was used to develop a method for source detection in the still evolving major epidemic of Q-fever in the Netherlands. All notified Q-fever cases in the area were interviewed. Postal codes of cases and of small ruminant farms (size >40 animals) located within 5 kilometres of the cluster area were geo-referenced as point locations in a GIS-model. For each farm, attack rates and relative risks were calculated for 5 concentric zones adding 1 kilometre at a time, using the 5-10 kilometres zone as reference. These data were linked to the results of veterinary investigations. Persons living within 2 kilometres of an affected dairy goat farm (>400 animals) had a much higher risk for Q-fever than those living more than 5 kilometres away (Relative risk 31.1 [95% CI 16.4-59.1]). The study supported the hypothesis that a single dairy goat farm was the source of the human outbreak. GIS-based attack rate analysis is a promising tool for source detection in outbreaks of human Q-fever.

  3. Recent Outbreaks of Rift Valley Fever in East Africa and the Middle East

    PubMed Central

    Himeidan, Yousif E.; Kweka, Eliningaya J.; Mahgoub, Mostafa M.; El Rayah, El Amin; Ouma, Johnson O.

    2014-01-01

    Rift Valley fever (RVF) is an important neglected, emerging, mosquito-borne disease with severe negative impact on human and animal health. Mosquitoes in the Aedes genus have been considered as the reservoir, as well as vectors, since their transovarially infected eggs withstand desiccation and larvae hatch when in contact with water. However, different mosquito species serve as epizootic/epidemic vectors of RVF, creating a complex epidemiologic pattern in East Africa. The recent RVF outbreaks in Somalia (2006–2007), Kenya (2006–2007), Tanzania (2007), and Sudan (2007–2008) showed extension to districts, which were not involved before. These outbreaks also demonstrated the changing epidemiology of the disease from being originally associated with livestock, to a seemingly highly virulent form infecting humans and causing considerably high-fatality rates. The amount of rainfall is considered to be the main factor initiating RVF outbreaks. The interaction between rainfall and local environment, i.e., type of soil, livestock, and human determine the space-time clustering of RVF outbreaks. Contact with animals or their products was the most dominant risk factor to transfer the infection to humans. Uncontrolled movement of livestock during an outbreak is responsible for introducing RVF to new areas. For example, the virus that caused the Saudi Arabia outbreak in 2000 was found to be the same strain that caused the 1997–98 outbreaks in East Africa. A strategy that involves active surveillance with effective case management and diagnosis for humans and identifying target areas for animal vaccination, restriction on animal movements outside the affected areas, identifying breeding sites, and targeted intensive mosquito control programs has been shown to succeed in limiting the effect of RVF outbreak and curb the spread of the disease from the onset. PMID:25340047

  4. Oral infection of Aedes aegypti with yellow fever virus: geographic variation and genetic considerations.

    PubMed

    Tabachnick, W J; Wallis, G P; Aitken, T H; Miller, B R; Amato, G D; Lorenz, L; Powell, J R; Beaty, B J

    1985-11-01

    Twenty-eight populations representing a worldwide distribution of Aedes aegypti were tested for their ability to become orally infected with yellow fever virus (YFV). Populations had been analyzed for genetic variations at 11 isozyme loci and assigned to one of 8 genetic geographic groups of Ae. aegypti. Infection rates suggest that populations showing isozyme genetic relatedness also demonstrate similarity to oral infection rates with YFV. The findings support the hypothesis that genetic variation exists for oral susceptibility to YFV in Ae. aegypti.

  5. Yellow fever vaccination status and safety in hemodialysis patients.

    PubMed

    Facincani, Tila; Guimarães, Maia Nogueira Crown; De Sousa Dos Santos, Sigrid

    2016-07-01

    The adverse effects of yellow fever (YF) vaccine in dialysis patients are not well known. There is concern about the risks and benefits of the vaccine in immunocompromised patients living in endemic areas, particularly given the risk of resurgence of urban YF with the spread of Aedes aegypti mosquitoes. The purpose of this study was to assess the coverage and safety of YF vaccine in chronic dialysis patients. A cross-sectional study of 130 chronic dialysis patients was performed. Data were collected on clinical characteristics and YF vaccine status. Patients not vaccinated against YF or without a booster vaccination within the last 10 years were referred to receive the vaccine, and adverse effects were monitored. Previous vaccination was verified in 44 patients within the last 10 years and in 26 patients at more than 10 years ago, with no mention of adverse effects. Thirty-six patients had never been vaccinated and 24 had an unknown vaccination status. Of the total 86 patients referred for immunization, 45 actually received the YF vaccine, with 24.4% experiencing mild local adverse effects and 4.4% experiencing fever. No serious adverse effects attributable to YF vaccine were observed (anaphylaxis, neurological or viscerotropic disease). YF vaccine coverage among hemodialysis patients is low, and the vaccine appeared to be safe in this population with a small sample size. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  6. How Brazil joined the quest for a yellow fever vaccine. Interview by Claudia Jurberg and Julia D'Aloisio..

    PubMed

    Benchimol, Jaime

    2013-03-01

    Brazil recently announced an agreement between its Bio-Manguinhos vaccine unit and two US companies to research and develop a new yellow fever vaccine. Claudia Jurberg and Julia D'Aloisio talk to Jaime Benchimol about the controversial history of the development of the vaccine that benefits millions of people today.

  7. Rift Valley fever in Namibia, 2010.

    PubMed

    Monaco, Federica; Pinoni, Chiara; Cosseddu, Gian Mario; Khaiseb, Siegfried; Calistri, Paolo; Molini, Umberto; Bishi, Alec; Conte, Annamaria; Scacchia, Massimo; Lelli, Rossella

    2013-12-01

    During May-July 2010 in Namibia, outbreaks of Rift Valley fever were reported to the National Veterinary Service. Analysis of animal specimens confirmed virus circulation on 7 farms. Molecular characterization showed that all outbreaks were caused by a strain of Rift Valley fever virus closely related to virus strains responsible for outbreaks in South Africa during 2009-2010.

  8. Epidemics which never came: yellow fever (1883) and bubonic plague (1902-1903) in Baja California

    PubMed

    Fierros-Hernández, Arturo; Ayala-Zúñiga, Alejandro

    2018-01-01

    This paper seeks to clarify the epidemic panorama that was generated in Baja California in the late nineteenth and early twentieth 20 th century’s, specifically that occurred in 1883 and 1902, years in which it is claimed occurred epidemics of yellow fever and bubonic plague respectively. However, as demonstrated in our study they never occurred due to social-demographic conditions in the area. Copyright: © 2018 SecretarÍa de Salud.

  9. Assessment of yellow fever epidemic risk: an original multi-criteria modeling approach.

    PubMed

    Briand, Sylvie; Beresniak, Ariel; Nguyen, Tim; Yonli, Tajoua; Duru, Gerard; Kambire, Chantal; Perea, William

    2009-07-14

    Yellow fever (YF) virtually disappeared in francophone West African countries as a result of YF mass vaccination campaigns carried out between 1940 and 1953. However, because of the failure to continue mass vaccination campaigns, a resurgence of the deadly disease in many African countries began in the early 1980s. We developed an original modeling approach to assess YF epidemic risk (vulnerability) and to prioritize the populations to be vaccinated. We chose a two-step assessment of vulnerability at district level consisting of a quantitative and qualitative assessment per country. Quantitative assessment starts with data collection on six risk factors: five risk factors associated with "exposure" to virus/vector and one with "susceptibility" of a district to YF epidemics. The multiple correspondence analysis (MCA) modeling method was specifically adapted to reduce the five exposure variables to one aggregated exposure indicator. Health districts were then projected onto a two-dimensional graph to define different levels of vulnerability. Districts are presented on risk maps for qualitative analysis in consensus groups, allowing the addition of factors, such as population migrations or vector density, that could not be included in MCA. The example of rural districts in Burkina Faso show five distinct clusters of risk profiles. Based on this assessment, 32 of 55 districts comprising over 7 million people were prioritized for preventive vaccination campaigns. This assessment of yellow fever epidemic risk at the district level includes MCA modeling and consensus group modification. MCA provides a standardized way to reduce complexity. It supports an informed public health decision-making process that empowers local stakeholders through the consensus group. This original approach can be applied to any disease with documented risk factors.

  10. Frog skin cultures secrete anti-yellow fever compounds.

    PubMed

    Muñoz-Camargo, Carolina; Méndez, Margarita Correa; Salazar, Vivian; Moscoso, Johanna; Narváez, Diana; Torres, Maria Mercedes; Florez, Franz Kaston; Groot, Helena; Mitrani, Eduardo

    2016-11-01

    There is an urgent need to develop novel antimicrobial substances. Antimicrobial peptides (AMPs) are considered as promising candidates for future therapeutic use. Because of the re-emergence of the Flavivirus infection, and particularly the yellow fever virus (YFV), we have compared the antiviral activities from skin secretions of seven different frog species against YFV (strain 17D). Secretions from Sphaenorhynchus lacteus, Cryptobatrachus boulongeri and Leptodactylus fuscus displayed the more powerful activities. S. lacteus was found to inhibit viral lysis of Vero E6 cells even at the highest viral concentration evaluated of 10 LD 50 . We also report the identification of a novel frenatin-related peptide from S. lacteus and found that this peptide-on its own-can lead to 35% protection against YVF, while displaying no cytotoxicity against somatic cells even at fivefold higher concentrations. These results are attractive and support the need for continued exploration of new sources of AMPs from frog skin secretions such as those described here in the development of new compounds for the treatment of infectious diseases in general and specific viral infections in particular.

  11. Haemorrhagic Fevers, Viral

    MedlinePlus

    ... Filoviridae (Ebola and Marburg) and Flaviviridae (yellow fever, dengue, Omsk haemorrhagic fever, Kyasanur forest disease). General information ... the Ebola vaccine trials in Guinea What is dengue and how is it treated? Fact sheets Crimean- ...

  12. Household Water Treatment Uptake during a Public Health Response to a Large Typhoid Fever Outbreak in Harare, Zimbabwe

    PubMed Central

    Imanishi, Maho; Kweza, Patience F.; Slayton, Rachel B.; Urayai, Tanaka; Ziro, Odrie; Mushayi, Wellington; Francis-Chizororo, Monica; Kuonza, Lazarus R.; Ayers, Tracy; Freeman, Molly M.; Govore, Emmaculate; Duri, Clemence; Chonzi, Prosper; Mtapuri-Zinyowera, Sekesai; Manangazira, Portia; Kilmarx, Peter H.; Mintz, Eric; Lantagne, Daniele

    2014-01-01

    Locally manufactured sodium hypochlorite (chlorine) solution has been sold in Zimbabwe since 2010. During October 1, 2011–April 30, 2012, 4,181 suspected and 52 confirmed cases of typhoid fever were identified in Harare. In response to this outbreak, chlorine tablets were distributed. To evaluate household water treatment uptake, we conducted a survey and water quality testing in 458 randomly selected households in two suburbs most affected by the outbreak. Although 75% of households were aware of chlorine solution and 85% received chlorine tablets, only 18% had reportedly treated stored water and had the recommended protective level of free chlorine residuals. Water treatment was more common among households that reported water treatment before the outbreak, and those that received free tablets during the outbreak (P < 0.01), but was not associated with chlorine solution awareness or use before the outbreak (P > 0.05). Outbreak response did not build on pre-existing prevention programs. PMID:24664784

  13. The risk of urban yellow fever resurgence in Aedes-infested American cities.

    PubMed

    Massad, Eduardo; Amaku, Marcos; Coutinho, Francisco Antonio Bezerra; Struchiner, Claudio José; Lopez, Luis Fernandez; Coelho, Giovanini; Wilder-Smith, Annelies; Burattini, Marcelo Nascimento

    2018-05-30

    Aedes aegypti, historically known as yellow fever (YF) mosquito, transmits a great number of other viruses such as Dengue, West Nile, Chikungunya, Zika, Mayaro and perhaps Oropouche, among others. Well established in Africa and Asia, Aedes mosquitoes are now increasingly invading large parts of the American continent, and hence the risk of urban YF resurgence in the American cities should because of great concern to public health authorities. Although no new urban cycle of YF was reported in the Americas since the end of an Aedes eradication programme in the late 1950s, the high number of non-vaccinated individuals that visit endemic areas, that is, South American jungles where the sylvatic cycle of YF is transmitted by canopy mosquitoes, and return to Aedes-infested urban areas, increases the risk of resurgence of the urban cycle of YF. We present a method to estimate the risk of urban YF resurgence in dengue-endemic cities. This method consists in (1) to estimate the number of Aedes mosquitoes that explains a given dengue outbreak in a given region; (2) calculate the force of infection caused by the introduction of one infective individual per unit area in the endemic area under study; (3) using the above estimates, calculate the probability of at least one autochthonous YF case per unit area produced by one single viraemic traveller per unit area arriving from a YF endemic or epidemic sylvatic region at the city studied. We demonstrate that, provided the relative vector competence, here defined as the capacity to being infected and disseminate the virus, of Ae. aegypti is greater than 0.7 (with respect to dengue), one infected traveller can introduce urban YF in a dengue endemic area.

  14. Rift Valley Fever Outbreak in Livestock in Kenya, 2006–2007

    PubMed Central

    Munyua, Peninah; Murithi, Rees M.; Wainwright, Sherrilyn; Githinji, Jane; Hightower, Allen; Mutonga, David; Macharia, Joseph; Ithondeka, Peter M.; Musaa, Joseph; Breiman, Robert F.; Bloland, Peter; Njenga, M. Kariuki

    2010-01-01

    We analyzed the extent of livestock involvement in the latest Rift Valley fever (RVF) outbreak in Kenya that started in December 2006 and continued until June 2007. When compared with previous RVF outbreaks in the country, the 2006–07 outbreak was the most extensive in cattle, sheep, goats, and camels affecting thousands of animals in 29 of 69 administrative districts across six of the eight provinces. This contrasted with the distribution of approximately 700 human RVF cases in the country, where over 85% of these cases were located in four districts; Garissa and Ijara districts in Northeastern Province, Baringo district in Rift Valley Province, and Kilifi district in Coast Province. Analysis of livestock and human data suggests that livestock infections occur before virus detection in humans, as supported by clustering of human RVF cases around livestock cases in Baringo district. The highest livestock morbidity and mortality rates were recorded in Garissa and Baringo districts, the same districts that recorded a high number of human cases. The districts that reported RVF in livestock for the first time in 2006/07 included Kitui, Tharaka, Meru South, Meru central, Mwingi, Embu, and Mbeere in Eastern Province, Malindi and Taita taveta in Coast Province, Kirinyaga and Murang'a in Central Province, and Baringo and Samburu in Rift Valley Province, indicating that the disease was occurring in new regions in the country. PMID:20682907

  15. Current status and future prospects of yellow fever vaccines.

    PubMed

    Beck, Andrew S; Barrett, Alan D T

    2015-01-01

    Yellow fever 17D vaccine is one of the oldest live-attenuated vaccines in current use that is recognized historically for its immunogenic and safe properties. These unique properties of 17D are presently exploited in rationally designed recombinant vaccines targeting not only flaviviral antigens but also other pathogens of public health concern. Several candidate vaccines based on 17D have advanced to human trials, and a chimeric recombinant Japanese encephalitis vaccine utilizing the 17D backbone has been licensed. The mechanism(s) of attenuation for 17D are poorly understood; however, recent insights from large in silico studies have indicated particular host genetic determinants contributing to the immune response to the vaccine, which presumably influences the considerable durability of protection, now in many cases considered to be lifelong. The very rare occurrence of severe adverse events for 17D is discussed, including a recent fatal case of vaccine-associated viscerotropic disease.

  16. Current Status and Future Prospects of Yellow Fever Vaccines

    PubMed Central

    Beck, Andrew S.; Barrett, Alan D.T.

    2017-01-01

    Summary Yellow fever 17D vaccine is one of the oldest live-attenuated vaccines in current use that is recognized for historically immunogenic and safe properties. These unique properties of 17D are presently exploited in rationally designed recombinant vaccines targeting not only flaviviral antigens but also other pathogens of public health concern. Several candidate vaccines based on 17D have advanced to human trials, and a chimeric recombinant Japanese encephalitis vaccine utilizing the 17D backbone has been licensed. The mechanism(s) of attenuation for 17D are poorly understood; however, recent insights from large in silico studies have indicated particular host genetic determinants contributing to the immune response to the vaccine, which presumably influences the considerable durability of protection, now in many cases considered to be life-long. The very rare occurrence of severe adverse events for 17D is discussed, including a recent fatal case of vaccine-associated viscerotropic disease. PMID:26366673

  17. Vector competence of Australian mosquitoes for yellow fever virus.

    PubMed

    van den Hurk, Andrew F; McElroy, Kate; Pyke, Alyssa T; McGee, Charles E; Hall-Mendelin, Sonja; Day, Andrew; Ryan, Peter A; Ritchie, Scott A; Vanlandingham, Dana L; Higgs, Stephen

    2011-09-01

    The vector competence of Australian mosquitoes for yellow fever virus (YFV) was evaluated. Infection and transmission rates in Cairns and Townsville populations of Aedes aegypti and a Brisbane strain of Ae. notoscriptus were not significantly different from a well-characterized YFV-susceptible strain of Ae. aegypti. After exposure to 10⁷·² tissue culture infectious dose (TCID₅₀)/mL of an African strain of YFV, > 70% of Ae. aegypti and Ae. notoscriptus became infected, and > 50% transmitted the virus. When exposed to 10⁶·⁷) TCID₅₀/mL of a South American strain of YFV, the highest infection (64%) and transmission (56%) rates were observed in Ae. notoscriptus. The infection and transmission rates in the Cairns Ae. aegypti were both 24%, and they were 36% and 28%, respectively, for the Townsville population. Because competent vectors are present, the limited number of travelers from endemic areas and strict vaccination requirements will influence whether YFV transmission occurs in Australia.

  18. Magnitude and frequency variations of vector-borne infection outbreaks using the Ross-Macdonald model: explaining and predicting outbreaks of dengue fever.

    PubMed

    Amaku, M; Azevedo, F; Burattini, M N; Coelho, G E; Coutinho, F A B; Greenhalgh, D; Lopez, L F; Motitsuki, R S; Wilder-Smith, A; Massad, E

    2016-08-19

    The classical Ross-Macdonald model is often utilized to model vector-borne infections; however, this model fails on several fronts. First, using measured (or estimated) parameters, which values are accepted from the literature, the model predicts a much greater number of cases than what is usually observed. Second, the model predicts a single large outbreak that is followed by decades of much smaller outbreaks, which is not consistent with what is observed. Usually towns or cities report a number of recurrences for many years, even when environmental changes cannot explain the disappearance of the infection between the peaks. In this paper, we continue to examine the pitfalls in modelling this class of infections, and explain that, if properly used, the Ross-Macdonald model works and can be used to understand the patterns of epidemics and even, to some extent, be used to make predictions. We model several outbreaks of dengue fever and show that the variable pattern of yearly recurrence (or its absence) can be understood and explained by a simple Ross-Macdonald model modified to take into account human movement across a range of neighbourhoods within a city. In addition, we analyse the effect of seasonal variations in the parameters that determine the number, longevity and biting behaviour of mosquitoes. Based on the size of the first outbreak, we show that it is possible to estimate the proportion of the remaining susceptible individuals and to predict the likelihood and magnitude of the eventual subsequent outbreaks. This approach is described based on actual dengue outbreaks with different recurrence patterns from some Brazilian regions.

  19. Two Adenovirus Serotype 3 Outbreaks Associated with Febrile Respiratory Disease and Pharyngoconjunctival Fever in Children under 15 Years of Age in Hangzhou, China, during 2011

    PubMed Central

    Xie, Li; Yu, Xin-Fen; Sun, Zhou; Yang, Xu-Hui; Huang, Ren-Jie; Wang, Jing; Yu, Apeng; Zheng, Lin; Yu, Man-Chu; Hu, Xiao-Wei; Wang, Ban-Ma; Chen, Jin; Pan, Jing-Cao

    2012-01-01

    Adenovirus serotype 3 and 7 outbreaks have occurred periodically in northern, eastern, and southern China since 1955, but there has been no report since the adenovirus serotype 7 outbreak first occurred in Hangzhou, China, in 1991. Here we explored the epidemiology and etiology of two adenovirus serotype 3 outbreaks in Hangzhou in 2011. One acute respiratory outbreak was found in Chun'an County, where a total of 371 cases were confirmed in 5 of 23 towns from 4 to 31 May 2011. The outbreak affected 18.57% (13/70) of schools and 14.49% (90/621) of classes. The incidence was 5.18% (371/7,163). The population was distributed among individuals ages 7 to 15 years. No parents or teachers were infected. Another pharyngoconjunctival fever outbreak was discovered in the Chenjinglun Swimming Center located in the Xihu District between 1 and 15 July 2011. A total of 134 cases were confirmed in 900 amateur swimmers, with an incidence of 14.89% (134/900). The ages ranged from 4 to 9 years. The two outbreaks had no severe complications or death. The viruses in 66.67% (10/15) of throat swabs from children with acute respiratory infections and 100% (10/10) of the swabs from children with pharyngoconjunctival fever were confirmed to be adenovirus serotype 3 with 100% homology by PCR. Of these samples, 60.0% (12/20) had a classical characteristic cytopathic effect, presented as grape-like clusters at 72 h after infection in HEp-2 cells. In conclusion, the acute respiratory infection and pharyngoconjunctival fever outbreak in Hangzhou were caused by the completely homologous type 3 adenovirus in subgenus B. Moreover, these outbreaks demonstrated rapid transmission rates, possibly due to close contact and droplet transmission. PMID:22442311

  20. Serological Evidence of Dengue Fever Among Refugees, Hargeysa, Somalia

    DTIC Science & Technology

    1989-01-01

    fever, Sindbis, Chikungunya, yellow HISTORY OF THE DISEASE IN THE fever, and Zika viruses . However, antibody reac- DAM CAMP tive to dengue 2 virus was...fever, Crimean-Congo hemorrhagic fever, Sindbis, Chikungunya, yellow fever, and Zika viruses . However, antibody reactive to dengue 2 virus was detected... ZIKA ) viruses . Further testing of sera for evidence of dengue S Barbera S , MOGAISCIO . viral infection was done by the enzyme immunoassay " (EIA

  1. The single kinin receptor signals to separate and independent physiological pathways in Malpighian tubules of the yellow fever mosquito

    USDA-ARS?s Scientific Manuscript database

    In the past we have used the leucokinins, the kinins of the cockroach Leucophaea, to evaluate the mechanism of diuretic action of kinin peptides in Malpighian tubules of the yellow fever mosquito Aedes aegypti. Now using aedeskinins, the kinins of Aedes, are available, we find that in isolated Aede...

  2. Molecular identification of the first local dengue fever outbreak in Shenzhen city, China: a potential imported vertical transmission from Southeast Asia?

    PubMed

    Yang, F; Guo, G Z; Chen, J Q; Ma, H W; Liu, T; Huang, D N; Yao, C H; Zhang, R L; Xue, C F; Zhang, L

    2014-02-01

    A suspected dengue fever outbreak occurred in 2010 at a solitary construction site in Shenzhen city, China. To investigate this epidemic, we used serological, molecular biological, and bioinformatics techniques. Of nine serum samples from suspected patients, we detected seven positive for dengue virus (DENV) antibodies, eight for DENV-1 RNA, and three containing live viruses. The isolated virus, SZ1029 strain, was sequenced and confirmed as DENV-1, showing the highest E-gene homology to D1/Malaysia/36000/05 and SG(EHI)DED142808 strains recently reported in Southeast Asia. Further phylogenetic tree analysis confirmed their close relationship. At the epidemic site, we also detected 14 asymptomatic co-workers (out of 291) positive for DENV antibody, and DENV-1-positive mosquitoes. Thus, we concluded that DENV-1 caused the first local dengue fever outbreak in Shenzhen. Because no imported case was identified, the molecular fingerprints of the SZ1029 strain suggest this outbreak may be due to vertical transmission imported from Southeast Asia.

  3. A crimean - congo haemorrhagic Fever outbreak in northern balochistan.

    PubMed

    Ali, Nadir; Chotani, Rashid A; Anwar, Masood; Nadeem, Mansoor; Karamat, Karamat Ahmed; Tariq, Waheed Uz Zaman

    2007-08-01

    To describe the clinical characteristics, epidemiology, predictors of fatal outcome (PFO), and management effects of Crimean-Congo haemorrhagic fever (CCHF) patients during an outbreak in Northern Balochistan. Descriptive study. Fatima Jinnah Hospital and Combined Military Hospital, Quetta, from June to October, 2001. Patients presenting with a fever of less than 2 weeks duration and bleeding manifestations were included. Clinical history was recorded and patients were placed on oral ribavirin, and hematological support. Diagnosis was established by PCR for CCHF or detection of CCHF specific IgM and IgG. Eighty-four patients were received, 34 (40.5%) were suspected of suffering from classical CCHF. All 34 (100%) patients presented with a history of fever and bleeding (epistaxis, gum bleeding, melena or haematuria). Mean platelet count was 30 x 109/L and mean ALT (alanine transferase) was 288 U/L. Among fatal cases, the mean platelet count was 18.4 x 109/L and ALT was 781 units/L. PCR for CCHF viral RNA performed on 10 patients was positive in 3 (30%) patients. CCHF specific IgM and IgG was positive in 17.6% (6/34). Four patients were brought in moribund condition and expired before treatment could be started, 4 patients expired during treatment and 76.5% (26/34) were cured. The overall mortality was 23.5% (8/34). Main predictors of fatal outcome were ALT Z 150 units/L, activated partial thromboplastin time(aPT) Z 60 seconds, prothrombin time (PT) Z 34 seconds, aspartate transferase (AST) Z 200 units/L, platelets 20 x 109/L, and fibrinogen 110 mg/dL. In this series of CCHF occurring in Northern parts of Balochistan, gastrointestinal tract bleeding was the worst prognostic factor associated with fatal outcome. Providing education to healthcare workers and at risk populations, hematological support, anti-viral drugs, and barrier nursing may help reduce mortality.

  4. Analysis of two imported cases of yellow fever infection from Ivory Coast and The Gambia to Germany and Belgium.

    PubMed

    Bae, Hi-Gung; Drosten, Christian; Emmerich, Petra; Colebunders, Robert; Hantson, Philippe; Pest, Stefan; Parent, Muriel; Schmitz, Herbert; Warnat, Marc-Aurel; Niedrig, Matthias

    2005-08-01

    Yellow fever remains one of the great burdens for public health in the endemic regions in Africa and South America. The under reporting of yellow fever cases in the respective regions and lack of international interest leads to an underestimation of the constant danger in these areas. Non-vaccinated travelers take a high risk without the effective protection of YFV 17D vaccination. Two YF cases were imported to Europe in the last 4 years. We characterized two yellow fever virus (YFV) isolates from severely infected patients coming back from Africa, Ivory Coast and The Gambia, by genome sequencing and phylogenetic analysis. The virus infections in different organs were analyzed with pathological, immunohistological, electronmicroscopical and quantitative real-time PCR methods. High virus loads in spleen and liver (2.4 x 10 (6) to 3 x 10 (7)GE/mL) demonstrated by real time PCR show massive virus replication leading to extraordinary progression of the disease in these patients. Immunohistological and electronmicroscopical analysis confirms virus particles in liver tissue. In all other organs no virus could be detected. A fast, specific and sensitive virus PCR detection is recommended for diagnostic of acute infections. The further sequence alignments show that the new isolates belong to the type II West African strain with great homology to over 40-year old YF isolates from Senegal and Ghana. The divergence observed was on average 3.3%, ranging from 0.0% to 5.0% in the coding region of Gambia 2001 strain and 2.9 %, ranging from 0.0% to 4.3% in the coding region of the Ivory C 1999 strain. Most mutations (5.0%/4.3%, respectively) occurred in the envelope protein.

  5. Detection of Coxiella burnetii DNA on Small-Ruminant Farms during a Q Fever Outbreak in the Netherlands

    PubMed Central

    van der Plaats, R. Q. J.; de Heer, L.; Paauwe, R.; Schimmer, B.; Vellema, P.; van Rotterdam, B. J.; van Duynhoven, Y. T. H. P.

    2012-01-01

    During large Q fever outbreaks in the Netherlands between 2007 and 2010, dairy goat farms were implicated as the primary source of human Q fever. The transmission of Coxiella burnetii to humans is thought to occur primarily via aerosols, although available data on C. burnetii in aerosols and other environmental matrices are limited. During the outbreak of 2009, 19 dairy goat farms and one dairy sheep farm were selected nationwide to investigate the presence of C. burnetii DNA in vaginal swabs, manure, surface area swabs, milk unit filters, and aerosols. Four of these farms had a positive status during the Coxiella burnetii bulk milk monitoring program in 2009 and additionally reported abortion waves in 2008 or 2009. Eleven farms were reported as having positive bulk milk only, and five selected (control) farms had a bulk milk-negative status in 2009 and no reported Q fever history. Screening by quantitative PCR (qPCR) revealed that on farms with a history of abortions related to C. burnetii and, to a lesser extent, on farms positive by bulk milk monitoring, generally higher proportions of positive samples and higher levels of C. burnetii DNA within positive samples were observed than on the control farms. The relatively high levels of C. burnetii DNA in surface area swabs and aerosols sampled in stables of bulk milk-positive farms, including farms with a Q fever-related abortion history, support the hypothesis that these farms can pose a risk for the transmission of C. burnetii to humans. PMID:22247143

  6. Assessment of Yellow Fever Epidemic Risk: An Original Multi-criteria Modeling Approach

    PubMed Central

    Briand, Sylvie; Beresniak, Ariel; Nguyen, Tim; Yonli, Tajoua; Duru, Gerard; Kambire, Chantal; Perea, William

    2009-01-01

    Background Yellow fever (YF) virtually disappeared in francophone West African countries as a result of YF mass vaccination campaigns carried out between 1940 and 1953. However, because of the failure to continue mass vaccination campaigns, a resurgence of the deadly disease in many African countries began in the early 1980s. We developed an original modeling approach to assess YF epidemic risk (vulnerability) and to prioritize the populations to be vaccinated. Methods and Findings We chose a two-step assessment of vulnerability at district level consisting of a quantitative and qualitative assessment per country. Quantitative assessment starts with data collection on six risk factors: five risk factors associated with “exposure” to virus/vector and one with “susceptibility” of a district to YF epidemics. The multiple correspondence analysis (MCA) modeling method was specifically adapted to reduce the five exposure variables to one aggregated exposure indicator. Health districts were then projected onto a two-dimensional graph to define different levels of vulnerability. Districts are presented on risk maps for qualitative analysis in consensus groups, allowing the addition of factors, such as population migrations or vector density, that could not be included in MCA. The example of rural districts in Burkina Faso show five distinct clusters of risk profiles. Based on this assessment, 32 of 55 districts comprising over 7 million people were prioritized for preventive vaccination campaigns. Conclusion This assessment of yellow fever epidemic risk at the district level includes MCA modeling and consensus group modification. MCA provides a standardized way to reduce complexity. It supports an informed public health decision-making process that empowers local stakeholders through the consensus group. This original approach can be applied to any disease with documented risk factors. PMID:19597548

  7. Dengue and yellow fever virus vectors: seasonal abundance, diversity and resting preferences in three Kenyan cities.

    PubMed

    Agha, Sheila B; Tchouassi, David P; Bastos, Armanda D S; Sang, Rosemary

    2017-12-29

    The transmission patterns of dengue (DENV) and yellow fever (YFV) viruses, especially in urban settings, are influenced by Aedes (Stegomyia) mosquito abundance and behavior. Despite recurrent dengue outbreaks on the Kenyan coast, these parameters remain poorly defined in this and other areas of contrasting dengue endemicity in Kenya. In assessing the transmission risk of DENV/YFV in three Kenyan cities, we determined adult abundance and resting habits of potential Aedes (Stegomyia) vectors in Kilifi (dengue-outbreak prone), and Nairobi and Kisumu (no dengue outbreaks reported). In addition, mosquito diversity, an important consideration for changing mosquito-borne disease dynamics, was compared. Between October 2014 and June 2016, host-seeking adult mosquitoes were sampled using CO 2 -baited BG-Sentinel traps (12 traps daily) placed in vegetation around homesteads, across study sites in the three major cities. Also, indoor and outdoor resting mosquitoes were sampled using Prokopack aspirators. Three samplings, each of five consecutive days, were conducted during the long-rains, short-rains and dry season for each city. Inter-city and seasonal variation in mosquito abundance and diversity was evaluated using general linear models while mosquito-resting preference (indoors vs outdoors) was compared using Chi-square test. Aedes aegypti, which comprised 60% (n = 7772) of the total 12,937 host-seeking mosquitoes collected, had comparable numbers in Kisumu (45.2%, n = 3513) and Kilifi (37.7%, n = 2932), both being significantly higher than Nairobi (17.1%, n = 1327). Aedes aegypti abundance was significantly lower in the short-rains and dry season relative to the long-rains (P < 0.0001). Aedes bromeliae, which occurred in low numbers, did not differ significantly between seasons or cities. Mosquito diversity was highest during the long-rains and in Nairobi. Only 10% (n = 43) of the 450 houses aspirated were found positive for resting Ae. aegypti

  8. Innate immunity phenotypic features point toward simultaneous raise of activation and modulation events following 17DD live attenuated yellow fever first-time vaccination.

    PubMed

    Martins, Marina Angela; Silva, Maria Luiza; Elói-Santos, Silvana Maria; Ribeiro, José Geraldo Leite; Peruhype-Magalhães, Vanessa; Marciano, Ana Paula Vieira; Homma, Akira; Kroon, Erna Geessien; Teixeira-Carvalho, Andréa; Martins-Filho, Olindo Assis

    2008-02-26

    Detailed multiparametric phenotypic investigation aiming to characterize the kinetics of the innate immune response in the peripheral blood following 17DD yellow fever (17DD-YF) first-time vaccination was performed. Results showed increased frequency of monocytes and NK cell subpopulations besides unexpected up-regulation of granulocytes activation status (CD28+/CD23+ and CD28+/HLA-DR+, respectively). Up-regulation of Fcgamma-R and IL-10-R expression emerge as putative events underlying the mixed pattern of phenotypic features triggered by the 17DD yellow fever (17DD-YF) vaccination. Mixed pattern of chemokine receptors expression further support our hypothesis that a parallel establishment of activation/modulation microenvironment plays a pivotal role in the protective immunity triggered by the 17DD-YF vaccine.

  9. Shifts in Geographic Distribution and Antimicrobial Resistance during a Prolonged Typhoid Fever Outbreak — Bundibugyo and Kasese Districts, Uganda, 2009–2011

    PubMed Central

    Walters, Maroya Spalding; Routh, Janell; Mikoleit, Matthew; Kadivane, Samuel; Ouma, Caroline; Mubiru, Denis; Mbusa, Ben; Murangi, Amos; Ejoku, Emmanuel; Rwantangle, Absalom; Kule, Uziah; Lule, John; Garrett, Nancy; Halpin, Jessica; Maxwell, Nikki; Kagirita, Atek; Mulabya, Fred; Makumbi, Issa; Freeman, Molly; Joyce, Kevin; Hill, Vince; Downing, Robert; Mintz, Eric

    2014-01-01

    Background Salmonella enterica serovar Typhi is transmitted by fecally contaminated food and water and causes approximately 22 million typhoid fever infections worldwide each year. Most cases occur in developing countries, where approximately 4% of patients develop intestinal perforation (IP). In Kasese District, Uganda, a typhoid fever outbreak notable for a high IP rate began in 2008. We report that this outbreak continued through 2011, when it spread to the neighboring district of Bundibugyo. Methodology/Principal Findings A suspected typhoid fever case was defined as IP or symptoms of fever, abdominal pain, and ≥1 of the following: gastrointestinal disruptions, body weakness, joint pain, headache, clinically suspected IP, or non-responsiveness to antimalarial medications. Cases were identified retrospectively via medical record reviews and prospectively through laboratory-enhanced case finding. Among Kasese residents, 709 cases were identified from August 1, 2009–December 31, 2011; of these, 149 were identified during the prospective period beginning November 1, 2011. Among Bundibugyo residents, 333 cases were identified from January 1–December 31, 2011, including 128 cases identified during the prospective period beginning October 28, 2011. IP was reported for 507 (82%) and 59 (20%) of Kasese and Bundibugyo cases, respectively. Blood and stool cultures performed for 154 patients during the prospective period yielded isolates from 24 (16%) patients. Three pulsed-field gel electrophoresis pattern combinations, including one observed in a Kasese isolate in 2009, were shared among Kasese and Bundibugyo isolates. Antimicrobial susceptibility was assessed for 18 isolates; among these 15 (83%) were multidrug-resistant (MDR), compared to 5% of 2009 isolates. Conclusions/Significance Molecular and epidemiological evidence suggest that during a prolonged outbreak, typhoid spread from Kasese to Bundibugyo. MDR strains became prevalent. Lasting interventions, such

  10. Evolution and molecular epidemiology of classical swine fever virus during a multi-annual outbreak amongst European wild boar.

    PubMed

    Goller, Katja V; Gabriel, Claudia; Dimna, Mireille Le; Le Potier, Marie-Frédérique; Rossi, Sophie; Staubach, Christoph; Merboth, Matthias; Beer, Martin; Blome, Sandra

    2016-03-01

    Classical swine fever is a viral disease of pigs that carries tremendous socio-economic impact. In outbreak situations, genetic typing is carried out for the purpose of molecular epidemiology in both domestic pigs and wild boar. These analyses are usually based on harmonized partial sequences. However, for high-resolution analyses towards the understanding of genetic variability and virus evolution, full-genome sequences are more appropriate. In this study, a unique set of representative virus strains was investigated that was collected during an outbreak in French free-ranging wild boar in the Vosges-du-Nord mountains between 2003 and 2007. Comparative sequence and evolutionary analyses of the nearly full-length sequences showed only slow evolution of classical swine fever virus strains over the years and no impact of vaccination on mutation rates. However, substitution rates varied amongst protein genes; furthermore, a spatial and temporal pattern could be observed whereby two separate clusters were formed that coincided with physical barriers.

  11. Duration of post-vaccination immunity against yellow fever in adults.

    PubMed

    2014-09-03

    Available scientific evidence to recommend or to advise against booster doses of yellow fever vaccine (YFV) is inconclusive. A study to estimate the seropositivity rate and geometric mean titres (GMT) of adults with varied times of vaccination was aimed to provide elements to revise the need and the timing of revaccination. Adults from the cities of Rio de Janeiro and Alfenas located in non-endemic areas in the Southeast of Brazil, who had one dose of YFV, were tested for YF neutralising antibodies and dengue IgG. Time (in years) since vaccination was based on immunisation cards and other reliable records. From 2011 to 2012 we recruited 691 subjects (73% males), aged 18-83 years. Time since vaccination ranged from 30 days to 18 years. Seropositivity rates (95%C.I.) and GMT (International Units/mL; 95%C.I.) decreased with time since vaccination: 93% (88-96%), 8.8 (7.0-10.9) IU/mL for newly vaccinated; 94% (88-97), 3.0 (2.5-3.6) IU/mL after 1-4 years; 83% (74-90), 2.2 (1.7-2.8) IU/mL after 5-9 years; 76% (68-83), 1.7 (1.4-2.0) IU/mL after 10-11 years; and 85% (80-90), 2.1 (1.7-2.5) IU/mL after 12 years or more. YF seropositivity rates were not affected by previous dengue infection. Eventhough serological correlates of protection for yellow fever are unknown, seronegativity in vaccinated subjects may indicate primary immunisation failure, or waning of immunity to levels below the protection threshold. Immunogenicity of YFV under routine conditions of immunisation services is likely to be lower than in controlled studies. Moreover, infants and toddlers, who comprise the main target group in YF endemic regions, and populations with high HIV infection rates, respond to YFV with lower antibody levels. In those settings one booster dose, preferably sooner than currently recommended, seems to be necessary to ensure longer protection for all vaccinees. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Yellow fever virus envelope protein expressed in insect cells is capable of syncytium formation in lepidopteran cells and could be used for immunodetection of YFV in human sera

    PubMed Central

    2011-01-01

    Background Yellow fever is an haemorrhagic disease caused by a virus that belongs to the genus Flavivirus (Flaviviridae family) and is transmitted by mosquitoes. Among the viral proteins, the envelope protein (E) is the most studied one, due to its high antigenic potencial. Baculovirus are one of the most popular and efficient eukaryotic expression system. In this study a recombinant baculovirus (vSynYFE) containing the envelope gene (env) of the 17D vaccine strain of yellow fever virus was constructed and the recombinant protein antigenicity was tested. Results Insect cells infected with vSynYFE showed syncytium formation, which is a cytopathic effect characteristic of flavivirus infection and expressed a polypeptide of around 54 kDa, which corresponds to the expected size of the recombinant E protein. Furthermore, the recombinant E protein expression was also confirmed by fluorescence microscopy of vSynYFE-infected insect cells. Total vSynYFE-infected insect extracts used as antigens detected the presence of antibodies for yellow fever virus in human sera derived from yellow fever-infected patients in an immunoassay and did not cross react with sera from dengue virus-infected patients. Conclusions The E protein expressed by the recombinant baculovirus in insect cells is antigenically similar to the wild protein and it may be useful for different medical applications, from improved diagnosis of the disease to source of antigens for the development of a subunit vaccine. PMID:21619598

  13. Yellow fever virus envelope protein expressed in insect cells is capable of syncytium formation in lepidopteran cells and could be used for immunodetection of YFV in human sera.

    PubMed

    Barros, Maria C E S; Galasso, Tatiane G C M; Chaib, Antônio J M; Degallier, Nicolas; Nagata, Tatsuya; Ribeiro, Bergmann M

    2011-05-27

    Yellow fever is an haemorrhagic disease caused by a virus that belongs to the genus Flavivirus (Flaviviridae family) and is transmitted by mosquitoes. Among the viral proteins, the envelope protein (E) is the most studied one, due to its high antigenic potencial. Baculovirus are one of the most popular and efficient eukaryotic expression system. In this study a recombinant baculovirus (vSynYFE) containing the envelope gene (env) of the 17D vaccine strain of yellow fever virus was constructed and the recombinant protein antigenicity was tested. Insect cells infected with vSynYFE showed syncytium formation, which is a cytopathic effect characteristic of flavivirus infection and expressed a polypeptide of around 54 kDa, which corresponds to the expected size of the recombinant E protein. Furthermore, the recombinant E protein expression was also confirmed by fluorescence microscopy of vSynYFE-infected insect cells. Total vSynYFE-infected insect extracts used as antigens detected the presence of antibodies for yellow fever virus in human sera derived from yellow fever-infected patients in an immunoassay and did not cross react with sera from dengue virus-infected patients. The E protein expressed by the recombinant baculovirus in insect cells is antigenically similar to the wild protein and it may be useful for different medical applications, from improved diagnosis of the disease to source of antigens for the development of a subunit vaccine.

  14. Entomological profile of yellow fever epidemics in the Central African Republic, 2006-2010.

    PubMed

    Ngoagouni, Carine; Kamgang, Basile; Manirakiza, Alexandre; Nangouma, Auguste; Paupy, Christophe; Nakoune, Emmanuel; Kazanji, Mirdad

    2012-08-16

    The causative agent of yellow fever is an arbovirus of the Flaviviridae family transmitted by infected Aedes mosquitoes, particularly in Africa. In the Central African Republic since 2006, cases have been notified in the provinces of Ombella-Mpoko, Ouham-Pende, Basse-Kotto, Haute-Kotto and in Bangui the capital. As the presence of a vector of yellow fever virus (YFV) represents a risk for spread of the disease, we undertook entomological investigations at these sites to identify potential vectors of YFV and their abundance. Between 2006 and 2010, 5066 mosquitoes belonging to six genera and 43 species were identified. The 20 species of the Aedes genus identified included Ae. aegypti, the main vector of YFV in urban settings, and species found in tropical forests, such as Ae. africanus, Ae. simpsoni, Ae. luteocephalus, Ae. vittatus and Ae. opok. These species were not distributed uniformly in the various sites studied. Thus, the predominant Aedes species was Ae. aegypti in Bangui (90.7 %) and Basse-Kotto (42.2 %), Ae. africanus in Ombella-Mpoko (67.4 %) and Haute-Kotto (77.8 %) and Ae. vittatus in Ouham-Pende (62.2 %). Ae. albopictus was also found in Bangui. The distribution of these dominant species differed significantly according to study site (P < 0.0001). None of the pooled homogenates of Aedes mosquitoes analysed by polymerase chain reaction contained the YFV genome. The results indicate a wide diversity of vector species for YFV in the Central African Republic. The establishment of surveillance and vector control programs should take into account the ecological specificity of each species.

  15. Remote Sensing Contributions to Prediction and Risk Assessment of Natural Disasters Caused by Large Scale Rift Valley Fever Outbreaks

    NASA Technical Reports Server (NTRS)

    Anyamba, Assaf; Linthicum, Kenneth J.; Small, Jennifer; Britch, S. C.; Tucker, C. J.

    2012-01-01

    Remotely sensed vegetation measurements for the last 30 years combined with other climate data sets such as rainfall and sea surface temperatures have come to play an important role in the study of the ecology of arthropod-borne diseases. We show that epidemics and epizootics of previously unpredictable Rift Valley fever are directly influenced by large scale flooding associated with the El Ni o/Southern Oscillation. This flooding affects the ecology of disease transmitting arthropod vectors through vegetation development and other bioclimatic factors. This information is now utilized to monitor, model, and map areas of potential Rift Valley fever outbreaks and is used as an early warning system for risk reduction of outbreaks to human and animal health, trade, and associated economic impacts. The continuation of such satellite measurements is critical to anticipating, preventing, and managing disease epidemics and epizootics and other climate-related disasters.

  16. Anomalous High Rainfall and Soil Saturation as Combined Risk Indicator of Rift Valley Fever Outbreaks, South Africa, 2008-2011.

    PubMed

    Williams, Roy; Malherbe, Johan; Weepener, Harold; Majiwa, Phelix; Swanepoel, Robert

    2016-12-01

    Rift Valley fever (RVF), a zoonotic vectorborne viral disease, causes loss of life among humans and livestock and an adverse effect on the economy of affected countries. Vaccination is the most effective way to protect livestock; however, during protracted interepidemic periods, farmers discontinue vaccination, which leads to loss of herd immunity and heavy losses of livestock when subsequent outbreaks occur. Retrospective analysis of the 2008-2011 RVF epidemics in South Africa revealed a pattern of continuous and widespread seasonal rainfall causing substantial soil saturation followed by explicit rainfall events that flooded dambos (seasonally flooded depressions), triggering outbreaks of disease. Incorporation of rainfall and soil saturation data into a prediction model for major outbreaks of RVF resulted in the correctly identified risk in nearly 90% of instances at least 1 month before outbreaks occurred; all indications are that irrigation is of major importance in the remaining 10% of outbreaks.

  17. Strong alkalinization in the anterior midgut of larval yellow fever mosquitoes (Aedes aegypti): involvement of luminal Na+/K+-ATPase.

    PubMed

    Onken, Horst; Patel, Malay; Javoroncov, Margarita; Izeirovski, Sejmir; Moffett, Stacia B; Moffett, David F

    2009-03-01

    Recently, Na(+)/K(+)-ATPase has been detected in the luminal membrane of the anterior midgut of larval yellow fever mosquitoes (Aedes aegypti) with immunohistochemical techniques. In this study, the possible involvement of this ATPase in strong alkalinization was investigated on the level of whole larvae, isolated and perfused midgut preparations and on the molecular level of the Na(+)/K(+)-ATPase protein. Ouabain (5 mM) did not inhibit the capability of intact larval mosquitoes to alkalinize their anterior midgut. Also in isolated and perfused midgut preparations the perfusion of the lumen with ouabain (5 mM) did not result in a significant change of the transepithelial voltage or the capacity of luminal alkalinization. Na(+)/K(+)-ATPase activity was completely abolished when KCl was substituted with choline chloride, suggesting that the enzyme cannot act as an ATP-driven Na(+)/H(+)-exchanger. Altogether the results of the present investigation indicate that apical Na(+)/K(+)-ATPase is not of direct importance for strong luminal alkalinization in the anterior midgut of larval yellow fever mosquitoes.

  18. Evaluation of Movement Restriction Zone Sizes in Controlling Classical Swine Fever Outbreaks

    PubMed Central

    Yadav, Shankar; Olynk Widmar, Nicole; Lay, Donald C.; Croney, Candace; Weng, Hsin-Yi

    2017-01-01

    The objective of this study was to compare the impacts of movement restriction zone sizes of 3, 5, 9, and 11 km with that of 7 km (the recommended zone size in the United States) in controlling a classical swine fever (CSF) outbreak. In addition to zone size, different compliance assumptions and outbreak types (single site and multiple site) were incorporated in the study. Three assumptions of compliance level were simulated: baseline, baseline ± 10%, and baseline ± 15%. The compliance level was held constant across all zone sizes in the baseline simulation. In the baseline ± 10% and baseline ± 15% simulations, the compliance level was increased for 3 and 5 km and decreased for 9 and 11 km from the baseline by the indicated percentages. The compliance level remained constant in all simulations for the 7-km zone size. Four single-site (i.e., with one index premises at the onset of outbreak) and four multiple-site (i.e., with more than one index premises at the onset of outbreak) CSF outbreak scenarios in Indiana were simulated incorporating various zone sizes and compliance assumptions using a stochastic between-premises disease spread model to estimate epidemic duration, percentage of infected, and preemptively culled swine premises. Furthermore, a risk assessment model that incorporated the results from the disease spread model was developed to estimate the number of swine premises under movement restrictions that would experience animal welfare outcomes of overcrowding or feed interruption during a CSF outbreak in Indiana. Compared with the 7-km zone size, the 3-km zone size resulted in a longer median epidemic duration, larger percentages of infected premises, and preemptively culled premises (P’s < 0.001) across all compliance assumptions and outbreak types. With the assumption of a higher compliance level, the 5-km zone size significantly (P < 0.001) reduced the epidemic duration and percentage of swine premises that would

  19. [Yellow fever virus 17D neutralising antibodies in vaccinated Colombian people and unvaccinated ones having immunity against dengue].

    PubMed

    Gómez, Sergio Y; Ocazionez, Raquel E

    2008-01-01

    Determining the frequency of yellow fever seroprotective antibody neutralising titres (YF-NT >or=1:10) in Colombians vaccinated with the 17 D virus and ascertaining the extent to which YF virus can be neutralised by dengue antibodies. Serum samples were taken from 100 subjects who showed their vaccination record and from 116 residents in municipalities (Norte de Santander) affected by a wild YF outbreak in 2002-2003 who were reported to have been YF vaccinated. Sera from individuals with (n=61) and without (n=16) dengue antibodies who had never been YF vaccinated were included. All the sera were tested by 75 % YF plaque-reduction neutralization test. YF-NT titres >or=1:10 were founded in 90 % of subjects with vaccination recorded with minors variations in relation to age. In contrast, there was correlation between decrease of seroprotective YF-NT titres frequency and increase of immunization time (r=0.95; p=0.04). In residents in YF endemic area, YF-NT titres >or= 1.10 were founded in 92,6 % adults and 69 % children. YF 17 D virus was neutralized (52-100 %) by dengue sera more efficiently than non-dengue immune sera (p<0.001). Individuals immunised with YF vaccine 17 D could not be protected against YF: up to 31% children and 10 % adults. Dengue antibodies inhibited YF virus and its significance in terms of YF protection must be investigated.

  20. Spatial and Temporal Pattern of Rift Valley Fever Outbreaks in Tanzania; 1930 to 2007

    PubMed Central

    Sindato, Calvin; Karimuribo, Esron D.; Pfeiffer, Dirk U.; Mboera, Leonard E. G.; Kivaria, Fredrick; Dautu, George; Bernard, Bett; Paweska, Janusz T.

    2014-01-01

    Background Rift Valley fever (RVF)-like disease was first reported in Tanzania more than eight decades ago and the last large outbreak of the disease occurred in 2006–07. This study investigates the spatial and temporal pattern of RVF outbreaks in Tanzania over the past 80 years in order to guide prevention and control strategies. Materials and Methods A retrospective study was carried out based on disease reporting data from Tanzania at district or village level. The data were sourced from the Ministries responsible for livestock and human health, Tanzania Meteorological Agency and research institutions involved in RVF surveillance and diagnosis. The spatial distribution of outbreaks was mapped using ArcGIS 10. The space-time permutation model was applied to identify clusters of cases, and a multivariable logistic regression model was used to identify risk factors associated with the occurrence of outbreaks in the district. Principal Findings RVF outbreaks were reported between December and June in 1930, 1947, 1957, 1960, 1963, 1968, 1977–79, 1989, 1997–98 and 2006–07 in 39.2% of the districts in Tanzania. There was statistically significant spatio-temporal clustering of outbreaks. RVF occurrence was associated with the eastern Rift Valley ecosystem (OR = 6.14, CI: 1.96, 19.28), total amount of rainfall of >405.4 mm (OR = 12.36, CI: 3.06, 49.88), soil texture (clay [OR = 8.76, CI: 2.52, 30.50], and loam [OR = 8.79, CI: 2.04, 37.82]). Conclusion/Significance RVF outbreaks were found to be distributed heterogeneously and transmission dynamics appeared to vary between areas. The sequence of outbreak waves, continuously cover more parts of the country. Whenever infection has been introduced into an area, it is likely to be involved in future outbreaks. The cases were more likely to be reported from the eastern Rift Valley than from the western Rift Valley ecosystem and from areas with clay and loam rather than sandy soil texture. PMID:24586433

  1. Laboratory diagnosis of Ebola hemorrhagic fever during an outbreak in Yambio, Sudan, 2004.

    PubMed

    Onyango, Clayton O; Opoka, Martin L; Ksiazek, Thomas G; Formenty, Pierre; Ahmed, Abdullahi; Tukei, Peter M; Sang, Rosemary C; Ofula, Victor O; Konongoi, Samson L; Coldren, Rodney L; Grein, Thomas; Legros, Dominique; Bell, Mike; De Cock, Kevin M; Bellini, William J; Towner, Jonathan S; Nichol, Stuart T; Rollin, Pierre E

    2007-11-15

    Between the months of April and June 2004, an Ebola hemorrhagic fever (EHF) outbreak was reported in Yambio county, southern Sudan. Blood samples were collected from a total of 36 patients with suspected EHF and were tested by enzyme-linked immunosorbent assay (ELISA) for immunoglobulin G and M antibodies, antigen ELISA, and reverse-transcription polymerase chain reaction (PCR) of a segment of the Ebolavirus (EBOV) polymerase gene. A total of 13 patients were confirmed to be infected with EBOV. In addition, 4 fatal cases were classified as probable cases, because no samples were collected. Another 12 patients were confirmed to have acute measles infection during the same period that EBOV was circulating. Genetic analysis of PCR-positive samples indicated that the virus was similar to but distinct from Sudan EBOV Maleo 1979. In response, case management, social mobilization, and follow-up of contacts were set up as means of surveillance. The outbreak was declared to be over on 7 August 2004.

  2. Dynamics of the CD8 T-cell response following yellow fever virus 17D immunization

    PubMed Central

    Co, Mary Dawn T; Kilpatrick, Elizabeth D; Rothman, Alan L

    2009-01-01

    Management of yellow fever is focused on the prevention of illness by the use of the yellow fever virus (YFV) 17D vaccine. The role of neutralizing antibodies in protection is generally accepted with YFV-specific T cells likely contributing to the control of viral replication. We studied CD8+ T-cell responses to four defined human leucocyte antigen-B35-restricted epitopes in YFV vaccine recipients as a model of the kinetics of cytotoxic T-lymphocyte responses to an acute human viral infection. Multiple features of these epitope-specific responses were analysed after vaccination including magnitude, cytokine production, phenotype and T-cell receptor repertoire. Peak peptide-specific interferon-γ (IFN-γ) responses of almost 1% of CD8+ T cells were seen as early as 2 weeks post-vaccination; however, dominant responses varied between donors. Peptide-specific responses were still detectable at 54 months post-vaccination. Tetramer-positive cells, at high frequencies, were detected as early as 7–9 days, before detectable IFN-γ-producing cells, suggesting a defect in the functional capacity of some antigen-specific cells early post-vaccination. The predominant memory phenotype of the tetramer-positive population was a differentiated effector (CD45RA+ CCR7− CD62L−) phenotype. The T-cell receptor Vβ analysis revealed a diverse oligoclonal repertoire in tetramer-positive T-cell populations in two individuals. These characteristics of the YFV-specific T-cell response could contribute to vaccine effectiveness. PMID:19740333

  3. Dynamics of the CD8 T-cell response following yellow fever virus 17D immunization.

    PubMed

    Co, Mary Dawn T; Kilpatrick, Elizabeth D; Rothman, Alan L

    2009-09-01

    Management of yellow fever is focused on the prevention of illness by the use of the yellow fever virus (YFV) 17D vaccine. The role of neutralizing antibodies in protection is generally accepted with YFV-specific T cells likely contributing to the control of viral replication. We studied CD8(+) T-cell responses to four defined human leucocyte antigen-B35-restricted epitopes in YFV vaccine recipients as a model of the kinetics of cytotoxic T-lymphocyte responses to an acute human viral infection. Multiple features of these epitope-specific responses were analysed after vaccination including magnitude, cytokine production, phenotype and T-cell receptor repertoire. Peak peptide-specific interferon-gamma (IFN-gamma) responses of almost 1% of CD8(+) T cells were seen as early as 2 weeks post-vaccination; however, dominant responses varied between donors. Peptide-specific responses were still detectable at 54 months post-vaccination. Tetramer-positive cells, at high frequencies, were detected as early as 7-9 days, before detectable IFN-gamma-producing cells, suggesting a defect in the functional capacity of some antigen-specific cells early post-vaccination. The predominant memory phenotype of the tetramer-positive population was a differentiated effector (CD45RA(+) CCR7(-) CD62L(-)) phenotype. The T-cell receptor Vbeta analysis revealed a diverse oligoclonal repertoire in tetramer-positive T-cell populations in two individuals. These characteristics of the YFV-specific T-cell response could contribute to vaccine effectiveness.

  4. Synthetic strategy and antiviral evaluation of diamide containing heterocycles targeting dengue and yellow fever virus.

    PubMed

    Saudi, Milind; Zmurko, Joanna; Kaptein, Suzanne; Rozenski, Jef; Gadakh, Bharat; Chaltin, Patrick; Marchand, Arnaud; Neyts, Johan; Van Aerschot, Arthur

    2016-10-04

    High-throughput screening of a subset of the CD3 chemical library (Centre for Drug Design and Discovery; KU Leuven) provided us with a lead compound 1, displaying low micromolar potency against dengue virus and yellow fever virus. Within a project aimed at discovering new inhibitors of flaviviruses, substitution of its central imidazole ring led to synthesis of variably substituted pyrazine dicarboxylamides and phthalic diamides, which were evaluated in cell-based assays for cytotoxicity and antiviral activity against the dengue virus (DENV) and yellow fever virus (YFV). Fourteen compounds inhibited DENV replication (EC50 ranging between 0.5 and 3.4 μM), with compounds 6b and 6d being the most potent inhibitors (EC50 0.5 μM) with selectivity indices (SI) > 235. Compound 7a likewise exhibited anti-DENV activity with an EC50 of 0.5 μM and an SI of >235. In addition, good antiviral activity of seven compounds in the series was also noted against the YFV with EC50 values ranging between 0.4 and 3.3 μM, with compound 6n being the most potent for this series with an EC50 0.4 μM and a selectivity index of >34. Finally, reversal of one of the central amide bonds as in series 13 proved deleterious to the inhibitory activity. Copyright © 2016 The Authors. Published by Elsevier Masson SAS.. All rights reserved.

  5. Lujo viral hemorrhagic fever: considering diagnostic capacity and preparedness in the wake of recent Ebola and Zika virus outbreaks.

    PubMed

    Simulundu, Edgar; Mweene, Aaron S; Changula, Katendi; Monze, Mwaka; Chizema, Elizabeth; Mwaba, Peter; Takada, Ayato; Ippolito, Guiseppe; Kasolo, Francis; Zumla, Alimuddin; Bates, Matthew

    2016-11-01

    Lujo virus is a novel Old World arenavirus identified in Southern Africa in 2008 as the cause of a viral hemorrhagic fever (VHF) characterized by nosocomial transmission with a high case fatality rate of 80% (4/5 cases). Whereas this outbreak was limited, the unprecedented Ebola virus disease outbreak in West Africa, and recent Zika virus disease epidemic in the Americas, has brought into acute focus the need for preparedness to respond to rare but potentially highly pathogenic outbreaks of zoonotic or arthropod-borne viral infections. A key determinant for effective control of a VHF outbreak is the time between primary infection and diagnosis of the index case. Here, we review the Lujo VHF outbreak of 2008 and discuss how preparatory measures with respect to developing diagnostic capacity might be effectively embedded into existing national disease control networks, such as those for human immunodeficiency virus, tuberculosis, and malaria. Copyright © 2016 John Wiley & Sons, Ltd.

  6. Guiding dengue vaccine development using knowledge gained from the success of the yellow fever vaccine.

    PubMed

    Liang, Huabin; Lee, Min; Jin, Xia

    2016-01-01

    Flaviviruses comprise approximately 70 closely related RNA viruses. These include several mosquito-borne pathogens, such as yellow fever virus (YFV), dengue virus (DENV), and Japanese encephalitis virus (JEV), which can cause significant human diseases and thus are of great medical importance. Vaccines against both YFV and JEV have been used successfully in humans for decades; however, the development of a DENV vaccine has encountered considerable obstacles. Here, we review the protective immune responses elicited by the vaccine against YFV to provide some insights into the development of a protective DENV vaccine.

  7. Guiding dengue vaccine development using knowledge gained from the success of the yellow fever vaccine

    PubMed Central

    Liang, Huabin; Lee, Min; Jin, Xia

    2016-01-01

    Flaviviruses comprise approximately 70 closely related RNA viruses. These include several mosquito-borne pathogens, such as yellow fever virus (YFV), dengue virus (DENV), and Japanese encephalitis virus (JEV), which can cause significant human diseases and thus are of great medical importance. Vaccines against both YFV and JEV have been used successfully in humans for decades; however, the development of a DENV vaccine has encountered considerable obstacles. Here, we review the protective immune responses elicited by the vaccine against YFV to provide some insights into the development of a protective DENV vaccine. PMID:26435066

  8. An unusual case of influenza-like illness after yellow fever vaccination.

    PubMed

    Lamson, Daryl M; Ramani, Rama; Kleabonas, Matthew; Metcalfe, Maureen; Humphrey, Charles; St George, Kirsten

    2014-05-01

    Yellow fever (YF) is an important public health concern in areas where the disease is endemic. For more than 60 years a highly effective live attenuated vaccine has been available, its widespread use resulting in a dramatic decrease in the number of cases. On rare occasions, YF vaccine can cause mild to severe disease and rare adverse vaccine-associated events have been reported. Additionally, an average viremia of 3-5 days after administration of the YF vaccine has been published. Here we present a case where YF vaccine was isolated in cell culture from a respiratory swab collected from a patient presenting with influenza-like illness. To the best of our knowledge, this is the first report finding replicating YF vaccine in the respiratory sample of a post inoculated individual. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. An outbreak of East Coast fever in a herd of Sanga cattle in Lutale, Central Province of Zambia.

    PubMed

    Minjauw, B; Otte, M J; James, A D; de Castro, J J; Permin, A; Di Giulo, G

    1998-05-01

    An outbreak of East Coast fever (ECF) occurred in an experimental herd of Sanga cattle maintained under a traditional rangeland grazing system at Lutale, Central Province of Zambia. Two groups of cattle had been kept under different tick-control regimens for several years prior to the introduction of the disease and epidemiological information on the outbreak were recorded. Weekly tick control was no sufficient to achieve full protection against Theileria parva infection. Systematic body temperature monitoring seems to be a good method for early detection of infection resulting in an important reduction of the case fatality rate after treatment with anti-theilerial drugs.

  10. Typhoid fever: A report on a point-source outbreak of 69 cases in Cape Town.

    PubMed

    Popkiss, M E

    1980-03-01

    In 1978, after a party in a Cape Town suburb attended by several hundred people, 69 persons were treated for typhoid fever. The precise source of the infection could not be traced, although it is reasonable to suppose that food eaten at the party had been contaminated by the main caterer. All 57 cultures of Salmonella typhi phage-typed were of phage type 46, including that obtained from the stool of the main caterer, who was asymptomatic. An epidemiological profile of the cases and an account of the management of the outbreak is given. There were no deaths and no patient became a carrier. Although the outbreak was contained, certain problems relating thereto are aired, including in particular the potential hazard of food-borne disease wherever housing and environmental standards are low.

  11. Epidemiological Assessment of the Rift Valley Fever Outbreak in Kenya and Tanzania in 2006 and 2007

    PubMed Central

    Jost, Christine C.; Nzietchueng, Serge; Kihu, Simon; Bett, Bernard; Njogu, George; Swai, Emmanuel S.; Mariner, Jeffrey C.

    2010-01-01

    To capture lessons from the 2007 Rift Valley fever (RVF) outbreak, epidemiological studies were carried out in Kenya and Tanzania. Somali pastoralists proved to be adept at recognizing symptoms of RVF and risk factors such as heavy rainfall and mosquito swarms. Sandik, which means “bloody nose,” was used by Somalis to denote disease consistent with RVF. Somalis reported that sandik was previously seen in 1997/98, the period of the last RVF epidemic. Pastoralists communicated valuable epidemiological information for surveillance and early warning systems that was observed before international warnings. The results indicate that an all or none approach to decision making contributed to the delay in response. In the future, a phased approach balancing actions against increasing risk of an outbreak would be more effective. Given the time required to mobilize large vaccine stocks, emergency vaccination did not contribute to the mitigation of explosive outbreaks of RVF. PMID:20682908

  12. Fever versus Fever: the role of host and vector susceptibility and interspecific competition in shaping the current and future distributions of the sylvatic cycles of dengue virus and yellow fever virus

    PubMed Central

    Hanley, Kathryn A.; Monath, Thomas P.; Weaver, Scott C.; Rossi, Shannan L.; Richman, Rebecca L.; Vasilakis, Nikos

    2013-01-01

    Two different species of flaviviruses, dengue virus (DENV) and yellow fever virus (YFV), that originated in sylvatic cycles maintained in non-human primates and forest-dwelling mosquitoes have emerged repeatedly into sustained human-to-human transmission by Aedes aegypti mosquitoes. Sylvatic cycles of both viruses remain active, and where the two viruses overlap in West Africa they utilize similar suites of monkeys and Aedes mosquitoes. These extensive similarities render the differences in the biogeography and epidemiology of the two viruses all the more striking. First, the sylvatic cycle of YFV originated in Africa and was introduced into the New World, probably as a result of the slave trade, but is absent in Asia; in contrast, sylvatic DENV likely originated in Asia and has spread to Africa but not to the New World. Second, while sylvatic YFV can emerge into extensive urban outbreaks in humans, these invariably die out, whereas four different types of DENV have established human transmission cycles that are ecologically and evolutionarily distinct from their sylvatic ancestors. Finally, transmission of YFV among humans has been documented only in Africa and the Americas, whereas DENV is transmitted among humans across most of the range of competent Aedes vectors, which in the last decade has included every continent save Antarctica. This review summarizes current understanding of sylvatic transmission cycles of YFV and DENV, considers possible explanations for their disjunct distributions, and speculates on the potential consequences of future establishment of a sylvatic cycle of DENV in the Americas. PMID:23523817

  13. Fever versus fever: the role of host and vector susceptibility and interspecific competition in shaping the current and future distributions of the sylvatic cycles of dengue virus and yellow fever virus.

    PubMed

    Hanley, Kathryn A; Monath, Thomas P; Weaver, Scott C; Rossi, Shannan L; Richman, Rebecca L; Vasilakis, Nikos

    2013-10-01

    Two different species of flaviviruses, dengue virus (DENV) and yellow fever virus (YFV), that originated in sylvatic cycles maintained in non-human primates and forest-dwelling mosquitoes have emerged repeatedly into sustained human-to-human transmission by Aedes aegypti mosquitoes. Sylvatic cycles of both viruses remain active, and where the two viruses overlap in West Africa they utilize similar suites of monkeys and Aedes mosquitoes. These extensive similarities render the differences in the biogeography and epidemiology of the two viruses all the more striking. First, the sylvatic cycle of YFV originated in Africa and was introduced into the New World, probably as a result of the slave trade, but is absent in Asia; in contrast, sylvatic DENV likely originated in Asia and has spread to Africa but not to the New World. Second, while sylvatic YFV can emerge into extensive urban outbreaks in humans, these invariably die out, whereas four different types of DENV have established human transmission cycles that are ecologically and evolutionarily distinct from their sylvatic ancestors. Finally, transmission of YFV among humans has been documented only in Africa and the Americas, whereas DENV is transmitted among humans across most of the range of competent Aedes vectors, which in the last decade has included every continent save Antarctica. This review summarizes current understanding of sylvatic transmission cycles of YFV and DENV, considers possible explanations for their disjunct distributions, and speculates on the potential consequences of future establishment of a sylvatic cycle of DENV in the Americas. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Anomalous High Rainfall and Soil Saturation as Combined Risk Indicator of Rift Valley Fever Outbreaks, South Africa, 2008–2011

    PubMed Central

    Malherbe, Johan; Weepener, Harold; Majiwa, Phelix; Swanepoel, Robert

    2016-01-01

    Rift Valley fever (RVF), a zoonotic vectorborne viral disease, causes loss of life among humans and livestock and an adverse effect on the economy of affected countries. Vaccination is the most effective way to protect livestock; however, during protracted interepidemic periods, farmers discontinue vaccination, which leads to loss of herd immunity and heavy losses of livestock when subsequent outbreaks occur. Retrospective analysis of the 2008–2011 RVF epidemics in South Africa revealed a pattern of continuous and widespread seasonal rainfall causing substantial soil saturation followed by explicit rainfall events that flooded dambos (seasonally flooded depressions), triggering outbreaks of disease. Incorporation of rainfall and soil saturation data into a prediction model for major outbreaks of RVF resulted in the correctly identified risk in nearly 90% of instances at least 1 month before outbreaks occurred; all indications are that irrigation is of major importance in the remaining 10% of outbreaks. PMID:27403563

  15. Assessment of risk of dengue and yellow fever virus transmission in three major Kenyan cities based on Stegomyia indices.

    PubMed

    Agha, Sheila B; Tchouassi, David P; Bastos, Armanda D S; Sang, Rosemary

    2017-08-01

    Dengue (DEN) and yellow fever (YF) are re-emerging in East Africa, with contributing drivers to this trend being unplanned urbanization and increasingly adaptable anthropophilic Aedes (Stegomyia) vectors. Entomological risk assessment of these diseases remains scarce for much of East Africa and Kenya even in the dengue fever-prone urban coastal areas. Focusing on major cities of Kenya, we compared DEN and YF risk in Kilifi County (DEN-outbreak-prone), and Kisumu and Nairobi Counties (no documented DEN outbreaks). We surveyed water-holding containers for mosquito immature (larvae/pupae) indoors and outdoors from selected houses during the long rains, short rains and dry seasons (100 houses/season) in each County from October 2014-June 2016. House index (HI), Breteau index (BI) and Container index (CI) estimates based on Aedes (Stegomyia) immature infestations were compared by city and season. Aedes aegypti and Aedes bromeliae were the main Stegomyia species with significantly more positive houses outdoors (212) than indoors (88) (n = 900) (χ2 = 60.52, P < 0.0001). Overall, Ae. aegypti estimates of HI (17.3 vs 11.3) and BI (81.6 vs 87.7) were higher in Kilifi and Kisumu, respectively, than in Nairobi (HI, 0.3; BI,13). However, CI was highest in Kisumu (33.1), followed by Kilifi (15.1) then Nairobi (5.1). Aedes bromeliae indices were highest in Kilifi, followed by Kisumu, then Nairobi with HI (4.3, 0.3, 0); BI (21.3, 7, 0.7) and CI (3.3, 3.3, 0.3), at the respective sites. HI and BI for both species were highest in the long rains, compared to the short rains and dry seasons. We found strong positive correlations between the BI and CI, and BI and HI for Ae. aegypti, with the most productive container types being jerricans, drums, used/discarded containers and tyres. On the basis of established vector index thresholds, our findings suggest low-to-medium risk levels for urban YF and high DEN risk for Kilifi and Kisumu, whereas for Nairobi YF risk was low while DEN risk

  16. Assessment of risk of dengue and yellow fever virus transmission in three major Kenyan cities based on Stegomyia indices

    PubMed Central

    Tchouassi, David P.; Bastos, Armanda D. S.; Sang, Rosemary

    2017-01-01

    Dengue (DEN) and yellow fever (YF) are re-emerging in East Africa, with contributing drivers to this trend being unplanned urbanization and increasingly adaptable anthropophilic Aedes (Stegomyia) vectors. Entomological risk assessment of these diseases remains scarce for much of East Africa and Kenya even in the dengue fever-prone urban coastal areas. Focusing on major cities of Kenya, we compared DEN and YF risk in Kilifi County (DEN-outbreak-prone), and Kisumu and Nairobi Counties (no documented DEN outbreaks). We surveyed water-holding containers for mosquito immature (larvae/pupae) indoors and outdoors from selected houses during the long rains, short rains and dry seasons (100 houses/season) in each County from October 2014-June 2016. House index (HI), Breteau index (BI) and Container index (CI) estimates based on Aedes (Stegomyia) immature infestations were compared by city and season. Aedes aegypti and Aedes bromeliae were the main Stegomyia species with significantly more positive houses outdoors (212) than indoors (88) (n = 900) (χ2 = 60.52, P < 0.0001). Overall, Ae. aegypti estimates of HI (17.3 vs 11.3) and BI (81.6 vs 87.7) were higher in Kilifi and Kisumu, respectively, than in Nairobi (HI, 0.3; BI,13). However, CI was highest in Kisumu (33.1), followed by Kilifi (15.1) then Nairobi (5.1). Aedes bromeliae indices were highest in Kilifi, followed by Kisumu, then Nairobi with HI (4.3, 0.3, 0); BI (21.3, 7, 0.7) and CI (3.3, 3.3, 0.3), at the respective sites. HI and BI for both species were highest in the long rains, compared to the short rains and dry seasons. We found strong positive correlations between the BI and CI, and BI and HI for Ae. aegypti, with the most productive container types being jerricans, drums, used/discarded containers and tyres. On the basis of established vector index thresholds, our findings suggest low-to-medium risk levels for urban YF and high DEN risk for Kilifi and Kisumu, whereas for Nairobi YF risk was low while DEN risk

  17. Fractional Dosing of Yellow Fever Vaccine to Extend Supply: A Modeling Study

    PubMed Central

    Peak, Corey M.; Leung, Gabriel M.

    2016-01-01

    Background The ongoing yellow fever (YF) epidemic in Angola strains the global vaccine supply, prompting WHO to adopt dose sparing for its vaccination campaign in Kinshasa in July–August 2016. Although a 5-fold fractional-dose vaccine is similar to standard-dose vaccine in safety and immunogenicity, efficacy is untested. There is an urgent need to ensure the robustness of fractional-dose vaccination by elucidating the conditions under which dose fractionation would reduce transmission. Methods We estimate the effective reproductive number for YF in Angola using disease natural history and case report data. With simple mathematical models of YF transmission, we calculate the infection attack rate (IAR, the proportion of population infected over the course of an epidemic) under varying levels of transmissibility and five-fold fractional-dose vaccine efficacy for two vaccination scenarios: (i) random vaccination in a hypothetical population that is completely susceptible; (ii) the Kinshasa vaccination campaign in July–August 2016 with different age cutoff for fractional-dose vaccines. Findings We estimate the effective reproductive number early in the Angola outbreak was between 5·2 and 7·1. If vaccine action is all-or-nothing (i.e. a proportion VE of vaccinees receives complete and the remainder receive no protection), n-fold fractionation can dramatically reduce IAR as long as efficacy VE exceeds 1/n. This benefit threshold becomes more stringent if vaccine action is leaky (i.e. the susceptibility of each vaccinee is reduced by a factor that is equal to the vaccine efficacy VE). The age cutoff for fractional-dose vaccines chosen by the WHO for the Kinshasa vaccination campaign (namely, 2 years) provides the largest reduction in IAR if the efficacy of five-fold fractional-dose vaccines exceeds 20%. Interpretation Dose fractionation is a very effective strategy for reducing infection attack rate that would be robust with a large margin for error in case

  18. Plasmid DNA initiates replication of yellow fever vaccine in vitro and elicits virus-specific immune response in mice

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tretyakova, Irina; Nickols, Brian; Hidajat, Rachmat

    Yellow fever (YF) causes an acute hemorrhagic fever disease in tropical Africa and Latin America. To develop a novel experimental YF vaccine, we applied iDNA infectious clone technology. The iDNA represents plasmid that encodes the full-length RNA genome of 17D vaccine downstream from a cytomegalovirus (CMV) promoter. The vaccine was designed to transcribe the full-length viral RNA and to launch 17D vaccine virus in vitro and in vivo. Transfection with 10 ng of iDNA plasmid was sufficient to start replication of vaccine virus in vitro. Safety of the parental 17D and iDNA-derived 17D viruses was confirmed in AG129 mice deficientmore » in receptors for IFN-α/β/γ. Finally, direct vaccination of BALB/c mice with a single 20 μg dose of iDNA plasmid resulted in seroconversion and elicitation of virus-specific neutralizing antibodies in animals. We conclude that iDNA immunization approach combines characteristics of DNA and attenuated vaccines and represents a promising vaccination strategy for YF. - Highlights: • The iDNA{sup ®} platform combines advantages of DNA and live attenuated vaccines. • Yellow fever (YF) 17D vaccine was launched from iDNA plasmid in vitro and in vivo. • Safety of iDNA-generated 17D virus was confirmed in AG129 mice. • BALB/c mice seroconverted after a single-dose vaccination with iDNA. • YF virus-neutralizing response was elicited in iDNA-vaccinated mice.« less

  19. Remote Sensing Contributions to Prediction and Risk Assessment of Natural Diasters Caused by Large Scale Rift Valley fever Outbreaks

    USDA-ARS?s Scientific Manuscript database

    Remotely sensed vegetation measurements for the last 30 years combined with other climate data sets such as rainfall and sea surface temperatures have come to play an important role in the study of the ecology of vector-borne diseases. We show that episodic outbreaks of Rift Valley fever are influen...

  20. Survival and swimming behavior of insecticide-exposed larvae and pupae of the yellow fever mosquito Aedes aegypti.

    PubMed

    Tomé, Hudson Vv; Pascini, Tales V; Dângelo, Rômulo Ac; Guedes, Raul Nc; Martins, Gustavo F

    2014-04-24

    The yellow fever mosquito Aedes aegypti is essentially a container-inhabiting species that is closely associated with urban areas. This species is a vector of human pathogens, including dengue and yellow fever viruses, and its control is of paramount importance for disease prevention. Insecticide use against mosquito juvenile stages (i.e. larvae and pupae) is growing in importance, particularly due to the ever-growing problems of resistance to adult-targeted insecticides and human safety concerns regarding such use in human dwellings. However, insecticide effects on insects in general and mosquitoes in particular primarily focus on their lethal effects. Thus, sublethal effects of such compounds in mosquito juveniles may have important effects on their environmental prevalence. In this study, we assessed the survival and swimming behavior of A. aegypti 4th instar larvae (L4) and pupae exposed to increasing concentrations of insecticides. We also assessed cell death in the neuromuscular system of juveniles. Third instar larvae of A. aegypti were exposed to different concentrations of azadirachtin, deltamethrin, imidacloprid and spinosad. Insect survival was assessed for 10 days. The distance swam, the resting time and the time spent in slow swimming were assessed in 4th instar larvae (L4) and pupae. Muscular and nervous cells of L4 and pupae exposed to insecticides were marked with the TUNEL reaction. The results from the survival bioassays were subjected to survival analysis while the swimming behavioral data were subjected to analyses of covariance, complemented with a regression analysis. All insecticides exhibited concentration-dependent effects on survival of larvae and pupae of the yellow fever mosquito. The pyrethroid deltamethrin was the most toxic insecticide followed by spinosad, imidacloprid, and azadirachtin, which exhibited low potency against the juveniles. All insecticides except azadirachtin reduced L4 swimming speed and wriggling movements. A

  1. Survival and swimming behavior of insecticide-exposed larvae and pupae of the yellow fever mosquito Aedes aegypti

    PubMed Central

    2014-01-01

    Background The yellow fever mosquito Aedes aegypti is essentially a container-inhabiting species that is closely associated with urban areas. This species is a vector of human pathogens, including dengue and yellow fever viruses, and its control is of paramount importance for disease prevention. Insecticide use against mosquito juvenile stages (i.e. larvae and pupae) is growing in importance, particularly due to the ever-growing problems of resistance to adult-targeted insecticides and human safety concerns regarding such use in human dwellings. However, insecticide effects on insects in general and mosquitoes in particular primarily focus on their lethal effects. Thus, sublethal effects of such compounds in mosquito juveniles may have important effects on their environmental prevalence. In this study, we assessed the survival and swimming behavior of A. aegypti 4th instar larvae (L4) and pupae exposed to increasing concentrations of insecticides. We also assessed cell death in the neuromuscular system of juveniles. Methods Third instar larvae of A. aegypti were exposed to different concentrations of azadirachtin, deltamethrin, imidacloprid and spinosad. Insect survival was assessed for 10 days. The distance swam, the resting time and the time spent in slow swimming were assessed in 4th instar larvae (L4) and pupae. Muscular and nervous cells of L4 and pupae exposed to insecticides were marked with the TUNEL reaction. The results from the survival bioassays were subjected to survival analysis while the swimming behavioral data were subjected to analyses of covariance, complemented with a regression analysis. Results All insecticides exhibited concentration-dependent effects on survival of larvae and pupae of the yellow fever mosquito. The pyrethroid deltamethrin was the most toxic insecticide followed by spinosad, imidacloprid, and azadirachtin, which exhibited low potency against the juveniles. All insecticides except azadirachtin reduced L4 swimming speed and

  2. [Poison and the mosquito: epistemological aspects of the etiology and prophylactics of yellow fever].

    PubMed

    Caponi, S

    2000-01-01

    The strategies against yellow fever developed by Argentina and Brazil were discussed at the Second Medical Congress of Latin America which was held in Buenos Aires in 1904. The study of the controversy between physicians from Argentina and Brazil around the existing explanatory models of this illness and the international prophylactic strategies in use at the time enables an epistemological understanding of the breakthrough brought about by the emergence of medicine of vectors. This chapter of Latin American medicine history constitutes a unique opportunity to analyze that reorganization of knowledge, which permitted the inclusion of intermediary living beings into the medical and epidemiological discourse.

  3. Climate teleconnections and recent patterns of human and animal disease outbreaks.

    PubMed

    Anyamba, Assaf; Linthicum, Kenneth J; Small, Jennifer L; Collins, Kathrine M; Tucker, Compton J; Pak, Edwin W; Britch, Seth C; Eastman, James Ronald; Pinzon, Jorge E; Russell, Kevin L

    2012-01-01

    Recent clusters of outbreaks of mosquito-borne diseases (Rift Valley fever and chikungunya) in Africa and parts of the Indian Ocean islands illustrate how interannual climate variability influences the changing risk patterns of disease outbreaks. Although Rift Valley fever outbreaks have been known to follow periods of above-normal rainfall, the timing of the outbreak events has largely been unknown. Similarly, there is inadequate knowledge on climate drivers of chikungunya outbreaks. We analyze a variety of climate and satellite-derived vegetation measurements to explain the coupling between patterns of climate variability and disease outbreaks of Rift Valley fever and chikungunya. We derived a teleconnections map by correlating long-term monthly global precipitation data with the NINO3.4 sea surface temperature (SST) anomaly index. This map identifies regional hot-spots where rainfall variability may have an influence on the ecology of vector borne disease. Among the regions are Eastern and Southern Africa where outbreaks of chikungunya and Rift Valley fever occurred 2004-2009. Chikungunya and Rift Valley fever case locations were mapped to corresponding climate data anomalies to understand associations between specific anomaly patterns in ecological and climate variables and disease outbreak patterns through space and time. From these maps we explored associations among Rift Valley fever disease occurrence locations and cumulative rainfall and vegetation index anomalies. We illustrated the time lag between the driving climate conditions and the timing of the first case of Rift Valley fever. Results showed that reported outbreaks of Rift Valley fever occurred after ∼3-4 months of sustained above-normal rainfall and associated green-up in vegetation, conditions ideal for Rift Valley fever mosquito vectors. For chikungunya we explored associations among surface air temperature, precipitation anomalies, and chikungunya outbreak locations. We found that chikungunya

  4. [Yellow fever: nurse counseling on travelers' health at basic health clinics].

    PubMed

    Mallet, Anna Paula; Dall'Agnol, Clarice Maria; Souza, Dirciara Barañano

    2010-06-01

    The objective of this qualitative, exploratory and descriptive study is to investigate the nursing practices related to travelers' health counseling. Data were collected from nursing professionals who work in the immunization sector of three Basic Health Units in Porto Alegre, Rio Grande do Sul, Brazil, using the technique of semi-structured interview. Five categories emerged from content analysis: care profile, health orientation, referrals to exchange the National Immunization Card for the International Certificate of Vaccination, information source and information material. The results signal the beginning of an organization of nursing practices focused on travelers' health, going beyond the focus on yellow fever. Failures in guidelines for acquisition of International Certificate of Vaccination still occur and information materials are missing. It points out to the need of broadening the discussion on travelers' health for a review of strategies for care organization and referrals for the construction of a specific policy.

  5. Trends of major disease outbreaks in the African region, 2003-2007.

    PubMed

    Kebede, Senait; Duales, Sambe; Yokouide, Allarangar; Alemu, Wondimagegnehu

    2010-03-01

    Communicable disease outbreaks cause millions of deaths throughout Sub-Saharan Africa each year. Most of the diseases causing epidemics in the region have been nearly eradicated or brought under control in other parts of the world. In recent years, considerable effort has been directed toward public health initiatives and strategies with a potential for significant impact in the fight against infectious diseases. In 1998, the World Health Organization African Regional Office (WHO/AFRO) launched the Integrated Disease Surveillance and Response (IDSR) strategy aimed at mitigating the impact of communicable diseases, including epidemic-prone diseases, through improving surveillance, laboratory confirmation and appropriate and timely public health interventions. Over the past decade, WHO and its partners have been providing technical and financial resources to African countries to strengthen epidemic preparedness and response (EPR) activities. This review examined the major epidemics reported to WHO/AFRO from 2003 to 2007. we conduct a review of documents and reports obtained from WHO/AFRO, WHO inter-country team, and partners and held meeting and discussions with key stakeholders to elicit the experiences of local, regional and international efforts against these epidemics to evaluate the lessons learned and to stimulate discussion on the future course for enhancing EPR. The most commonly reported epidemic outbreaks in Africa include: cholera, dysentery, malaria and hemorrhagic fevers (e.g. Ebola, Rift Valley fever, Crimean-Congo fever and yellow fever). The cyclic meningococcal meningitis outbreak that affects countries along the "meningitis belt" (spanning Sub-Saharan Africa from Senegal and The Gambia to Kenya and Ethiopia) accounts for other major epidemics in the region. The reporting of disease outbreaks to WHO/AFRO has improved since the launch of the IDSR strategy in 1998. Although the epidemic trends for cholera showed a decline in case fatality rate (CFR

  6. THE SECOND BLIND SPOT: SMALL RETINAL VESSEL VASCULOPATHY AFTER VACCINATION AGAINST NEISSERIA MENINGITIDIS AND YELLOW FEVER.

    PubMed

    Moysidis, Stavros N; Koulisis, Nicole; Patel, Vivek R; Kashani, Amir H; Rao, Narsing A; Humayun, Mark S; Rodger, Damien C

    2017-01-01

    To describe a case of small retinal vessel vasculopathy postvaccination. We report the case of a 41-year-old white man who presented with a "second blind spot," describing a nasal scotoma in the right eye that started 4 days after vaccinations against Neisseria meningitidis and the yellow fever virus, and after a 2-month period of high stress and decreased sleep. Clinical examination, Humphrey visual field testing, and multimodal imaging with fundus photographs, autofluorescence, fluorescein angiography, and spectral domain optical coherence tomography and angiography were performed. Clinical examination revealed a well-circumscribed, triangular area of retinal graying of about 1-disk diameter in size, located at the border of the temporal macula. This corresponded to a deep scotoma similar in size to the physiologic blind spot on Humphrey visual field 24-2 testing. There was mild hypoautofluoresence of this lesion on autofluorescence, hypofluorescence on fluorescein angiography, and focal attenuation of a small artery just distal to the bifurcation of an artery supplying the involved area. Spectral domain optical coherence tomography through the lesion conveyed hyperreflectivity most prominent in the inner and outer plexiform layers, with extension of the hyperreflectivity into the ganglion cell and inner nuclear layers. Spectral domain optical coherence tomography angiography demonstrated arteriolar and capillary dropout, more pronounced in the superficial retinal layer compared to the deeper retinal layer. At 1-month follow-up, his scotoma improved with monitoring, with reduction from -32 dB to -7 dB on Humphrey visual field testing. There was clinical resolution of the area of graying and decreased hyperreflectivity on spectral domain optical coherence tomography, with atrophy of the inner retina. Spectral domain optical coherence tomography angiography showed progression of arteriolar and capillary dropout, more so in the superficial than in the deep capillary

  7. Characterizing a large outbreak of dengue fever in Guangdong Province, China.

    PubMed

    Xiao, Jian-Peng; He, Jian-Feng; Deng, Ai-Ping; Lin, Hua-Liang; Song, Tie; Peng, Zhi-Qiang; Wu, Xiao-Cheng; Liu, Tao; Li, Zhi-Hao; Rutherford, Shannon; Zeng, Wei-Lin; Li, Xing; Ma, Wen-Jun; Zhang, Yong-Hui

    2016-05-03

    Dengue cases have been reported each year for the past 25 years in Guangdong Province, China with a recorded historical peak in 2014. This study aims to describe the epidemiological characteristics of this large outbreak in order to better understand its epidemic factors and to inform control strategies. Data for clinically diagnosed and laboratory-confirmed dengue fever cases in 2014 were extracted from the China Notifiable Infectious Disease Reporting System. We analyzed the incidence and characteristics of imported and indigenous cases in terms of population, temporal and spatial distributions. A total of 45 224 dengue fever cases and 6 deaths were notified in Guangdong Province in 2014, with an incidence of 47.3 per 100 000 people. The elderly (65+ years) represented 11.7 % of total indigenous cases with the highest incidence (72.3 per 100 000). Household workers and the unemployed accounted for 23.1 % of indigenous cases. The majority of indigenous cases occurred in the 37(th) to 44(th) week of 2014 (September and October) and almost all (20 of 21) prefecture-level cities in Guangdong were affected. Compared to the non-Pearl River Delta Region, the Pearl River Delta Region accounted for the majority of dengue cases and reported cases earlier in 2014. Dengue virus serotypes 1 (DENV-1), 2 (DENV-2) and 3 (DENV-3) were detected and DENV-1 was predominant (88.4 %). Dengue fever is a serious public health problem and is emerging as a continuous threat in Guangdong Province. There is an urgent need to enhance dengue surveillance and control, especially for the high-risk populations in high-risk areas.

  8. Predicting Rift Valley Fever Inter-epidemic Activities and Outbreak Patterns: Insights from a Stochastic Host-Vector Model.

    PubMed

    Pedro, Sansao A; Abelman, Shirley; Tonnang, Henri E Z

    2016-12-01

    Rift Valley fever (RVF) outbreaks are recurrent, occurring at irregular intervals of up to 15 years at least in East Africa. Between outbreaks disease inter-epidemic activities exist and occur at low levels and are maintained by female Aedes mcintoshi mosquitoes which transmit the virus to their eggs leading to disease persistence during unfavourable seasons. Here we formulate and analyse a full stochastic host-vector model with two routes of transmission: vertical and horizontal. By applying branching process theory we establish novel relationships between the basic reproduction number, R0, vertical transmission and the invasion and extinction probabilities. Optimum climatic conditions and presence of mosquitoes have not fully explained the irregular oscillatory behaviour of RVF outbreaks. Using our model without seasonality and applying van Kampen system-size expansion techniques, we provide an analytical expression for the spectrum of stochastic fluctuations, revealing how outbreaks multi-year periodicity varies with the vertical transmission. Our theory predicts complex fluctuations with a dominant period of 1 to 10 years which essentially depends on the efficiency of vertical transmission. Our predictions are then compared to temporal patterns of disease outbreaks in Tanzania, Kenya and South Africa. Our analyses show that interaction between nonlinearity, stochasticity and vertical transmission provides a simple but plausible explanation for the irregular oscillatory nature of RVF outbreaks. Therefore, we argue that while rainfall might be the major determinant for the onset and switch-off of an outbreak, the occurrence of a particular outbreak is also a result of a build up phenomena that is correlated to vertical transmission efficiency.

  9. Predicting Rift Valley Fever Inter-epidemic Activities and Outbreak Patterns: Insights from a Stochastic Host-Vector Model

    PubMed Central

    Pedro, Sansao A.; Abelman, Shirley; Tonnang, Henri E. Z.

    2016-01-01

    Rift Valley fever (RVF) outbreaks are recurrent, occurring at irregular intervals of up to 15 years at least in East Africa. Between outbreaks disease inter-epidemic activities exist and occur at low levels and are maintained by female Aedes mcintoshi mosquitoes which transmit the virus to their eggs leading to disease persistence during unfavourable seasons. Here we formulate and analyse a full stochastic host-vector model with two routes of transmission: vertical and horizontal. By applying branching process theory we establish novel relationships between the basic reproduction number, R0, vertical transmission and the invasion and extinction probabilities. Optimum climatic conditions and presence of mosquitoes have not fully explained the irregular oscillatory behaviour of RVF outbreaks. Using our model without seasonality and applying van Kampen system-size expansion techniques, we provide an analytical expression for the spectrum of stochastic fluctuations, revealing how outbreaks multi-year periodicity varies with the vertical transmission. Our theory predicts complex fluctuations with a dominant period of 1 to 10 years which essentially depends on the efficiency of vertical transmission. Our predictions are then compared to temporal patterns of disease outbreaks in Tanzania, Kenya and South Africa. Our analyses show that interaction between nonlinearity, stochasticity and vertical transmission provides a simple but plausible explanation for the irregular oscillatory nature of RVF outbreaks. Therefore, we argue that while rainfall might be the major determinant for the onset and switch-off of an outbreak, the occurrence of a particular outbreak is also a result of a build up phenomena that is correlated to vertical transmission efficiency. PMID:28002417

  10. The challenges of detecting and responding to a Lassa fever outbreak in an Ebola-affected setting.

    PubMed

    Hamblion, E L; Raftery, P; Wendland, A; Dweh, E; Williams, G S; George, R N C; Soro, L; Katawera, V; Clement, P; Gasasira, A N; Musa, E; Nagbe, T K

    2018-01-01

    Lassa fever (LF), a priority emerging pathogen likely to cause major epidemics, is endemic in much of West Africa and is difficult to distinguish from other viral hemorrhagic fevers, including Ebola virus disease (EVD). Definitive diagnosis requires laboratory confirmation, which is not widely available in affected settings. The public health action to contain a LF outbreak and the challenges encountered in an EVD-affected setting are reported herein. In February 2016, a rapid response team was deployed in Liberia in response to a cluster of LF cases. Active case finding, case investigation, contact tracing, laboratory testing, environmental investigation, risk communication, and community awareness raising were undertaken. From January to June 2016, 53 suspected LF cases were reported through the Integrated Disease Surveillance and Response system (IDSR). Fourteen cases (26%) were confirmed for LF, 14 (26%) did not have a sample tested, and 25 (47%) were classified as not a case following laboratory analysis. The case fatality rate in the confirmed cases was 29%. One case of international exportation was reported from Sweden. Difficulties were identified in timely specimen collection, packaging, and transportation (in confirmed cases, the time from sample collection to sample result ranged from 2 to 64 days) and a lack of response interventions for early cases. The delay in response to this outbreak could have been related to a number of challenges in this EVD-affected setting: a need to strengthen the IDSR system, develop preparedness plans, train rapid response teams, and build laboratory capacity. Prioritizing these actions will aid in the timely response to future outbreaks. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. Co-administration of live measles and yellow fever vaccines and inactivated pentavalent vaccines is associated with increased mortality compared with measles and yellow fever vaccines only. An observational study from Guinea-Bissau.

    PubMed

    Fisker, Ane Bærent; Ravn, Henrik; Rodrigues, Amabelia; Østergaard, Marie Drivsholm; Bale, Carlito; Benn, Christine Stabell; Aaby, Peter

    2014-01-23

    Studies from low-income countries indicate that co-administration of inactivated diphtheria-tetanus-pertussis (DTP) vaccine and live attenuated measles vaccine (MV) is associated with increased mortality compared with receiving MV only. Pentavalent (DTP-H. Influenza type B-Hepatitis B) vaccine is replacing DTP in many low-income countries and yellow fever vaccine (YF) has been introduced to be given together with MV. Pentavalent and YF vaccines were introduced in Guinea-Bissau in 2008. We investigated whether co-administration of pentavalent vaccine with MV and yellow fever vaccine has similar negative effects. In 2007-2011, we conducted a randomised placebo-controlled trial of vitamin A at routine vaccination contacts among children aged 6-23 months in urban and rural Guinea-Bissau. In the present study, we included 2331 children randomised to placebo who received live vaccines only (MV or MV+YF) or a combination of live and inactivated vaccines (MV+DTP or MV+YF+pentavalent). Mortality was compared in Cox proportional hazards models stratified for urban/rural enrolment adjusted for age and unevenly distributed baseline factors. While DTP was still used 685 children received MV only and 358 MV+DTP; following the change in programme, 940 received MV+YF only and 348 MV+YF+pentavalent. During 6 months of follow-up, the adjusted mortality rate ratio (MRR) for co-administered live and inactivated vaccines compared with live vaccines only was 3.24 (1.20-8.73). For MV+YF+pentavalent compared with MV+YF only, the adjusted MRR was 7.73 (1.79-33.4). In line with previous studies of DTP, the present results indicate that pentavalent vaccine co-administered with MV and YF is associated with increased mortality. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Pre-clinical efficacy and safety of experimental vaccines based on non-replicating vaccinia vectors against yellow fever.

    PubMed

    Schäfer, Birgit; Holzer, Georg W; Joachimsthaler, Alexandra; Coulibaly, Sogue; Schwendinger, Michael; Crowe, Brian A; Kreil, Thomas R; Barrett, P Noel; Falkner, Falko G

    2011-01-01

    Currently existing yellow fever (YF) vaccines are based on the live attenuated yellow fever virus 17D strain (YFV-17D). Although, a good safety profile was historically attributed to the 17D vaccine, serious adverse events have been reported, making the development of a safer, more modern vaccine desirable. A gene encoding the precursor of the membrane and envelope (prME) protein of the YFV-17D strain was inserted into the non-replicating modified vaccinia virus Ankara and into the D4R-defective vaccinia virus. Candidate vaccines based on the recombinant vaccinia viruses were assessed for immunogenicity and protection in a mouse model and compared to the commercial YFV-17D vaccine. The recombinant live vaccines induced γ-interferon-secreting CD4- and functionally active CD8-T cells, and conferred full protection against lethal challenge already after a single low immunization dose of 10(5) TCID(50). Surprisingly, pre-existing immunity against wild-type vaccinia virus did not negatively influence protection. Unlike the classical 17D vaccine, the vaccinia virus-based vaccines did not cause mortality following intracerebral administration in mice, demonstrating better safety profiles. The non-replicating recombinant YF candidate live vaccines induced a broad immune response after single dose administration, were effective even in the presence of a pre-existing immunity against vaccinia virus and demonstrated an excellent safety profile in mice.

  13. Frequency of histopathological changes in Howler monkeys ( Alouatta sp.) naturally infected with yellow fever virus in Brazil.

    PubMed

    Leal, Silvana Gomes; Romano, Alessandro Pecego Martins; Monteiro, Rafael Veríssimo; Melo, Cristiano Barros de; Vasconcelos, Pedro Fernando da Costa; Castro, Márcio Botelho de

    2016-02-01

    Due to the importance that Howler monkeys have on the yellow fever (YF) epidemiological sylvatic cycle in Brazil, more accurate morphological diagnostic criteria needs to be established, especially considering the differences that may exist between the genera of Brazilian non-human primates (NHPs) involved in yellow fever virus (YFV) epizootics. Records of YF epizootics in NHPs in Brazil between 2007 and 2009 were obtained from the Brazilian Ministry of Health database to select YF positive (n=98) Howler monkeys (Alouatta sp.) for this study. The changes described in the histopathological reports were categorized by organ and their frequencies calculated. The most frequent lesions observed in the animals with YF were hepatocyte apoptosis (Councilman body formation), midzonal hepatocyte necrosis, steatosis, liver hemorrhage, inflammatory mononuclear cell infiltration of the liver, renal acute tubular necrosis and interstitial nephritis. Midzonal hepatocyte necrosis, steatosis and hemorrhage presented positive correlations with apoptosis of hepatocytes, suggesting strong YFV pathogenic effect association; they were also the main histopathological changes in the Alouatta sp. A pronounced negative correlation between apoptosis of hepatocytes and hepatic mononuclear cell infiltration pointed to significant histopathological differences between YFV infection in Howler monkeys and humans. The results warn that NHPs may exhibit different response patterns following YFV infection and require a more careful diagnosis. Presumptive diagnosis based on primate histopathological lesions may contribute to public health service control.

  14. Community knowledge, attitudes and practices on Yellow fever in South Omo area, Southern Ethiopia.

    PubMed

    Legesse, Mengistu; Endale, Adugna; Erku, Woldearegay; Tilahun, Getachew; Medhin, Girmay

    2018-04-01

    Yellow fever (Yf) outbreak was recently reported in South Omo of Southern Ethiopia. This area was also highly affected by Yf outbreak in the 1960s. However, there is no reliable information on the level of community knowledge attitudes and practices about the disease in the area. The objective of the current study was to assess level of community knowledge, attitudes and practices about Yf. Between March and May 2017, a community-based cross-sectional survey was conducted in two districts of the South Omo area. During the survey, 612 randomly selected adults were interviewed about Yf using structured questionnaire. Out of the 612 study participants, 508 (83.0%) reported that they heard about Yf which is locally known as "a disease that causes vomiting blood". Most (90.4%) of the study participants also said that Yf is different from malaria. Two hundred thirteen (41.9%) participants said that Yf can be transmitted from a patient to another person, while only 80 (37.6%) mentioned that the disease is transmitted through mosquitoes bite. Out of 333 (65.7%) study participants who believed that Yf is a preventable disease, 280 (84.1%) mentioned vaccine as a preventive method. The majority believed that the disease is a killer (97.2%) and a newly emerging (69.4%). Among the total of 612 study participants, 221(36.1%) were considered as having a high level of overall knowledge of Yf. Having educational level above 7th grade (AOR = 3.25, 95% CI: 1.39, 7.57, p = 0.006) and being resident of Bena-Tsemay district (AOR = 1.77, 95% CI: 1.12, 2.78, P = 0.014) were significantly associated with having a high level of overall knowledge of Yf. Agro-pastoralism as an occupation compared to farming was associated with having a low level of overall knowledge of Yf (AOR = 0.51, 95% CI, 0.33, 0.79, P = 0.003). The findings indicate that most of the study community members had a low level of overall knowledge of Yf, especially about its cause, mode of transmission and preventive methods

  15. Transmission Dynamics of Rift Valley Fever Virus: Effects of Live and Killed Vaccines on Epizootic Outbreaks and Enzootic Maintenance

    PubMed Central

    Chamchod, Farida; Cosner, Chris; Cantrell, R. Stephen; Beier, John C.; Ruan, Shigui

    2016-01-01

    Rift Valley fever virus (RVFV) is an arthropod-borne viral pathogen that causes significant morbidity and mortality in small ruminants throughout Africa and the Middle East. Due to the sporadic and explosive nature of RVF outbreaks, vaccination has proved challenging to reduce RVFV infection in the ruminant population. Currently, there are two available types of vaccines, live and killed, in endemic areas. In this study, two mathematical models have been developed to explore the impact of live and killed vaccines on the transmission dynamics of RVFV. We demonstrate in general that vaccination helps reduce the severity of RVF outbreaks and that less delay in implementation and more vaccination attempts and effective vaccines can reduce the outbreak magnitude and the endemic number of RVFV. However, an introduction of a number of ruminants vaccinated by live vaccines in RVFV-free areas may cause an outbreak and RVFV may become endemic if there is sustained use of live vaccines. Other factors that are the important determinants of RVF outbreaks include: unsustained vaccination programs, recruitment of susceptible ruminants, and the seasonal abundance of mosquitoes. PMID:26869999

  16. Minimizing Spatial Variability of Healthcare Spatial Accessibility-The Case of a Dengue Fever Outbreak.

    PubMed

    Chu, Hone-Jay; Lin, Bo-Cheng; Yu, Ming-Run; Chan, Ta-Chien

    2016-12-13

    Outbreaks of infectious diseases or multi-casualty incidents have the potential to generate a large number of patients. It is a challenge for the healthcare system when demand for care suddenly surges. Traditionally, valuation of heath care spatial accessibility was based on static supply and demand information. In this study, we proposed an optimal model with the three-step floating catchment area (3SFCA) to account for the supply to minimize variability in spatial accessibility. We used empirical dengue fever outbreak data in Tainan City, Taiwan in 2015 to demonstrate the dynamic change in spatial accessibility based on the epidemic trend. The x and y coordinates of dengue-infected patients with precision loss were provided publicly by the Tainan City government, and were used as our model's demand. The spatial accessibility of heath care during the dengue outbreak from August to October 2015 was analyzed spatially and temporally by producing accessibility maps, and conducting capacity change analysis. This study also utilized the particle swarm optimization (PSO) model to decrease the spatial variation in accessibility and shortage areas of healthcare resources as the epidemic went on. The proposed method in this study can help decision makers reallocate healthcare resources spatially when the ratios of demand and supply surge too quickly and form clusters in some locations.

  17. Dengue fever outbreak: a clinical management experience.

    PubMed

    Ahmed, Shahid; Ali, Nadir; Ashraf, Shahzad; Ilyas, Mohammad; Tariq, Waheed-Uz-Zaman; Chotani, Rashid A

    2008-01-01

    To determine the frequency of dengue as a cause of fever and compare the clinical and haematological characteristics of Dengue-probable and Dengue-proven cases. An observational study. The Combined Military Hospital, Malir Cantt., Karachi, from August 2005 to December 2006. All patients with age above 14 years, who were either hospitalized or treated in medical outdoor clinic due to acute febrile illness, were evaluated for clinical features of Dengue Fever (DF), Dengue haemorrhagic fever (DHF) and Dengue Shock Syndrome (DSS). Patients showing typical clinical features and haematological findings suggestive of Dengue fever (As per WHO criteria) were evaluated in detail for comparison of probable and confirmed cases of Dengue fever. All other cases of acute febrile illness, not showing clinical features or haematological abnormalities of Dengue fever, were excluded. The clinical and laboratory features were recorded on SPSS 11.0 programme and graded where required, for descriptive and statistical analysis. Out of 5200 patients with febrile illness, 107(2%) presented with typical features of DF, 40/107(37%) were Dengue-proven while 67/107(63%) were Dengue-probable. Out of Dengue-proven cases, 38 were of DF and 2 were of DHF. Day 1 temperature ranged from 99-1050C (mean 1010C). Chills and rigors were noticed in 86 (80%), myalgia in 67%, headache in 54%, pharyngitis in 35%, rash in 28%, and bleeding manifestations in 2% cases. Hepatomegaly in 1(0.5%), lymphadenopathy in 1(0.5%) and splenomegaly in 12 (11.2%) cases. Leucopoenia (count<4x109 /L) was noted in 73%, platelet count<150 x109 /L in 84% and ALT>40 U/L in 57% cases. Frequency of clinically suspected dengue virus infection was 107 (2%), while confirmed dengue fever cases were 40 (0.8%) out of 5200 fever cases. Fever with chills and rigors, body aches, headache, myalgia, rash, haemorrhagic manifestations, platelet count, total leukocyte count, and ALT, are parameters to screen the cases of suspected dengue virus

  18. Climate Teleconnections and Recent Patterns of Human and Animal Disease Outbreaks

    PubMed Central

    Anyamba, Assaf; Linthicum, Kenneth J.; Small, Jennifer L.; Collins, Kathrine M.; Tucker, Compton J.; Pak, Edwin W.; Britch, Seth C.; Eastman, James Ronald; Pinzon, Jorge E.; Russell, Kevin L.

    2012-01-01

    Background Recent clusters of outbreaks of mosquito-borne diseases (Rift Valley fever and chikungunya) in Africa and parts of the Indian Ocean islands illustrate how interannual climate variability influences the changing risk patterns of disease outbreaks. Although Rift Valley fever outbreaks have been known to follow periods of above-normal rainfall, the timing of the outbreak events has largely been unknown. Similarly, there is inadequate knowledge on climate drivers of chikungunya outbreaks. We analyze a variety of climate and satellite-derived vegetation measurements to explain the coupling between patterns of climate variability and disease outbreaks of Rift Valley fever and chikungunya. Methods and Findings We derived a teleconnections map by correlating long-term monthly global precipitation data with the NINO3.4 sea surface temperature (SST) anomaly index. This map identifies regional hot-spots where rainfall variability may have an influence on the ecology of vector borne disease. Among the regions are Eastern and Southern Africa where outbreaks of chikungunya and Rift Valley fever occurred 2004–2009. Chikungunya and Rift Valley fever case locations were mapped to corresponding climate data anomalies to understand associations between specific anomaly patterns in ecological and climate variables and disease outbreak patterns through space and time. From these maps we explored associations among Rift Valley fever disease occurrence locations and cumulative rainfall and vegetation index anomalies. We illustrated the time lag between the driving climate conditions and the timing of the first case of Rift Valley fever. Results showed that reported outbreaks of Rift Valley fever occurred after ∼3–4 months of sustained above-normal rainfall and associated green-up in vegetation, conditions ideal for Rift Valley fever mosquito vectors. For chikungunya we explored associations among surface air temperature, precipitation anomalies, and chikungunya outbreak

  19. Evidence for the presence of African swine fever virus in an endemic region of Western Kenya in the absence of any reported outbreak.

    PubMed

    Thomas, Lian F; Bishop, Richard P; Onzere, Cynthia; Mcintosh, Michael T; Lemire, Karissa A; de Glanville, William A; Cook, E Anne J; Fèvre, Eric M

    2016-09-08

    African swine fever (ASF), caused by African swine fever virus (ASFV), is a severe haemorrhagic disease of pigs, outbreaks of which can have a devastating impact upon commercial and small-holder pig production. Pig production in western Kenya is characterised by low-input, free-range systems practised by poor farmers keeping between two and ten pigs. These farmers are particularly vulnerable to the catastrophic loss of livestock assets experienced in an ASF outbreak. This study wished to expand our understanding of ASFV epidemiology during a period when no outbreaks were reported. Two hundred and seventy six whole blood samples were analysed using two independent conventional and real time PCR assays to detect ASFV. Despite no recorded outbreak of clinical ASF during this time, virus was detected in 90/277 samples analysed by conventional PCR and 142/209 samples analysed by qPCR. Genotyping of a sub-set of these samples indicated that the viruses associated with the positive samples were classified within genotype IX and that these strains were therefore genetically similar to the virus associated with the 2006/2007 ASF outbreaks in Kenya. The detection of ASFV viral DNA in a relatively high number of pigs delivered for slaughter during a period with no reported outbreaks provides support for two hypotheses, which are not mutually exclusive: (1) that virus prevalence may be over-estimated by slaughter-slab sampling, relative to that prevailing in the wider pig population; (2) that sub-clinical, chronically infected or recovered pigs may be responsible for persistence of the virus in endemic areas.

  20. BCX4430, a novel nucleoside analog, effectively treats yellow fever in a Hamster model.

    PubMed

    Julander, Justin G; Bantia, Shanta; Taubenheim, Brian R; Minning, Dena M; Kotian, Pravin; Morrey, John D; Smee, Donald F; Sheridan, William P; Babu, Yarlagadda S

    2014-11-01

    No effective antiviral therapies are currently available to treat disease after infection with yellow fever virus (YFV). A Syrian golden hamster model of yellow fever (YF) was used to characterize the effect of treatment with BCX4430, a novel adenosine nucleoside analog. Significant improvement in survival was observed after treatment with BCX4430 at 4 mg/kg of body weight per day dosed intraperitoneally (i.p.) twice daily (BID). Treatment with BCX4430 at 12.5 mg/kg/day administered i.p. BID for 7 days offered complete protection from mortality and also resulted in significant improvement of other YF disease parameters, including weight loss, serum alanine aminotransferase levels (6 days postinfection [dpi]), and viremia (4 dpi). In uninfected hamsters, BCX4430 at 200 mg/kg/day administered i.p. BID for 7 days was well tolerated and did not result in mortality or weight loss, suggesting a potentially wide therapeutic index. Treatment with BCX4430 at 12 mg/kg/day i.p. remained effective when administered once daily and for only 4 days. Moreover, BCX4430 dosed at 200 mg/kg/day i.p. BID for 7 days effectively treated YF, even when treatment was delayed up to 4 days after virus challenge, corresponding with peak viral titers in the liver and serum. BCX4430 treatment did not preclude a protective antibody response, as higher neutralizing antibody (nAb) concentrations corresponded with increasing delays of treatment initiation, and greater nAb responses resulted in the protection of animals from a secondary challenge with YFV. In summary, BCX4430 is highly active in a hamster model of YF, even when treatment is initiated at the peak of viral replication. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  1. Crimean-Congo Hemorrhagic Fever (CCHF)

    MedlinePlus

    ... Congo Hemorrhagic Fever (CCHF) [PDF – 2 pages] Virus Ecology Viral Hemorrhagic Fever (VHF) Information for Specific Groups ... Diagnosis Treatment Prevention Outbreak Distribution Map Resources Virus Ecology File Formats Help: How do I view different ...

  2. International Health Regulations in practice: Focus on yellow fever and poliomyelitis.

    PubMed

    Simons, H; Patel, D

    2016-10-02

    ASBTRACT The spread of infectious disease represents a global threat and therefore remains a priority on the international public health agenda. The International Health Regulations (IHR) (2005) came into effect in June 2007 and provide a legal framework to which the 196 member states of the World Health Assembly agree to abide. 1 These regulations include implementation of protective, control and response measures at points of entry to a country (i.e. land borders, sea and airports), and of notification measures, all of which aim to prevent or limit the spread of disease while minimising disruption to international trade. The World Health Organization can apply and enforce IHR (2005) to any disease considered to pose a significant threat to international public health. This short paper focuses on 2 diseases; yellow fever and poliomyelitis, both of which have the potential to spread internationally. It will discuss the measures applied under IHR (2005) to minimize the threat, and explore the implications for both travelers and travel health advisors.

  3. TLR expression and NK cell activation after human yellow fever vaccination.

    PubMed

    Neves, Patrícia Cristina da Costa; Matos, Denise Cristina de Souza; Marcovistz, Rugimar; Galler, Ricardo

    2009-09-18

    The yellow fever vaccine is very effective with a single injection conferring protection for at least 10 years. Recent evidence suggests that the innate immune cells activated through Toll-like receptors (TLRs), are critical determinants of the robustness of the adaptive response. Therefore, we investigated the NK cell status in eight healthy volunteers after vaccination with YF 17DD virus. Shortly after vaccination, we observed increased expression of TLR-3 and TLR-9 in NK cells and markers such as CD69, HLA-DP-DQ-DR, CD38 and CD16. The up-regulation of CD69 was positively correlated with the presence of TLRs throughout the post-vaccination period and the circulating IFN-gamma was significantly augmented. These results suggest that TLRs may play an important role in NK cell activation during the immune response to vaccination, indicating a potential role for NK cells in helping the development of long-lasting protective memory.

  4. Construction and applications of yellow fever virus replicons.

    PubMed

    Jones, Christopher T; Patkar, Chinmay G; Kuhn, Richard J

    2005-01-20

    Subgenomic replicons of yellow fever virus (YFV) were constructed to allow expression of heterologous reporter genes in a replication-dependent manner. Expression of the antibiotic resistance gene neomycin phosphotransferase II (Neo) from one of these YFV replicons allowed selection of a stable population of cells (BHK-REP cells) in which the YFV replicon persistently replicated. BHK-REP cells were successfully used to trans-complement replication-defective YFV replicons harboring large internal deletions within either the NS1 or NS3 proteins. Although replicons with large deletions in either NS1 or NS3 were trans-complemented in BHK-REP, replicons that contained deletions of NS3 were trans-complemented at lower levels. In addition, replicons that retained the N-terminal protease domain of NS3 in cis were trans-complemented with higher efficiency than replicons in which both the protease and helicase domains of NS3 were deleted. To study packaging of YFV replicons, Sindbis replicons were constructed that expressed the YFV structural proteins in trans. Using these Sindbis replicons, both replication-competent and trans-complemented, replication-defective YFV replicons could be packaged into pseudo-infectious particles (PIPs). Although these results eliminate a potential role of either NS1 or full-length NS3 in cis for packaging and assembly of the flavivirus virion, they do not preclude the possibility that these proteins may act in trans during these processes.

  5. Travel characteristics and yellow fever vaccine usage among US Global TravEpiNet travelers visiting countries with risk of yellow fever virus transmission, 2009-2011.

    PubMed

    Jentes, Emily S; Han, Pauline; Gershman, Mark D; Rao, Sowmya R; LaRocque, Regina C; Staples, J Erin; Ryan, Edward T

    2013-05-01

    Yellow fever (YF) vaccine-associated serious adverse events and changing YF epidemiology have challenged healthcare providers to vaccinate only travelers whose risk of YF during travel is greater than their risk of adverse events. We describe the travel characteristics and YF vaccine use among US travelers visiting Global TravEpiNet clinics from January of 2009 to March of 2011. Of 16,660 travelers, 5,588 (34%) had itineraries to areas with risk of YF virus transmission. Of those travelers visiting one country with YF risk (N = 4,517), 71% were vaccinated at the visit, and 20% were presumed to be immune from prior vaccination. However, travelers visiting friends and relatives (odds ratio [OR] = 2.57, 95% confidence interval [95% CI] = 1.27-5.22) or going to Nigeria (OR = 3.01, 95% CI = 1.37-6.62) were significantly more likely to decline vaccination. To optimize YF vaccine use, clinicians should discuss an individual's risk-benefit assessment of vaccination and close knowledge gaps regarding vaccine use among at-risk populations.

  6. Phylogeographic reconstruction of African yellow fever virus isolates indicates recent simultaneous dispersal into east and west Africa.

    PubMed

    Beck, Andrew; Guzman, Hilda; Li, Li; Ellis, Brett; Tesh, Robert B; Barrett, Alan D T

    2013-01-01

    Yellow fever virus (YFV) is a mosquito-borne flavivirus that is a major public health problem in tropical areas of Africa and South America. There have been detailed studies on YFV ecology in West Africa and South America, but current understanding of YFV circulation on the African continent is incomplete. This inadequacy is especially notable for East and Central Africa, for which the unpredictability of human outbreaks is compounded by limitations in both historical and present surveillance efforts. Sparse availability of nucleotide sequence data makes it difficult to investigate the dispersal of YFV in these regions of the continent. To remedy this, we constructed Bayesian phylogenetic and geographic analyses utilizing 49 partial genomic sequences to infer the structure of YFV divergence across the known range of the virus on the African continent. Relaxed clock analysis demonstrated evidence for simultaneous divergence of YFV into east and west lineages, a finding that differs from previous hypotheses of YFV dispersal from reservoirs located on edges of the endemic range. Using discrete and continuous geographic diffusion models, we provide detailed structure of YFV lineage diversity. Significant transition links between extant East and West African lineages are presented, implying connection between areas of known sylvatic cycling. The results of demographic modeling reinforce the existence of a stably maintained population of YFV with spillover events into human populations occurring periodically. Geographically distinct foci of circulation are reconstructed, which have significant implications for studies of YFV ecology and emergence of human disease. We propose further incorporation of Bayesian phylogeography into formal GIS analyses to augment studies of arboviral disease.

  7. Investigation of an outbreak of craniofacial deformity in yellow-eyed penguin (Megadyptes antipodes) chicks.

    PubMed

    Buckle, K N; Young, M J; Alley, M R

    2014-09-01

    To investigate an outbreak of severe craniofacial deformity in yellow-eyed penguin (Megadyptes antipodes, hōiho) chicks at a single breeding site on the Otago Peninsula in the South Island of New Zealand. Morbidity and mortality of yellow-eyed penguins breeding on the coastal regions of Otago was monitored from November 2008 to March 2009. Dead chicks and unhatched eggs were recovered and examined. Between October and December 2008 32 eggs were recorded at 17 nests in the Okia Reserve. Eleven chicks survived to about 90 days of age, of which eight were found to have moderate to severe craniofacial deformity. The six most severe chicks were subject to euthanasia and examined in detail at necropsy, and the remaining two affected chicks were released to the wild after a period of care in a rehabilitation centre. Post-mortem samples were analysed for inorganic and organic toxins. The six deformed chicks all had severe shortening of the mandible and maxilla by 20-50 mm. The rostral and caudal regions of the skull were approximately 40 and 80% of normal length, respectively. Other, more variable lesions included cross bill deformity, malformed bill keratin, microphthalmia with misshapen scleral ossicles and oral soft tissue excess thought to be secondary to bony malformations. During the same year, mild sporadic bill deformities were also reported in 10 unrelated chicks from >167 chicks at other breeding sites on the southern Otago coast. Concentrations of organic toxins and heavy metals in body tissues from affected chicks were apparently similar to those in unaffected chicks on other beaches. No cause of this outbreak of craniofacial deformity could be established although the high prevalence at a single site suggests that it was due to an unidentified local teratogen.

  8. Pathophysiologic and transcriptomic analyses of viscerotropic yellow fever in a rhesus macaque model.

    PubMed

    Engelmann, Flora; Josset, Laurence; Girke, Thomas; Park, Byung; Barron, Alex; Dewane, Jesse; Hammarlund, Erika; Lewis, Anne; Axthelm, Michael K; Slifka, Mark K; Messaoudi, Ilhem

    2014-01-01

    Infection with yellow fever virus (YFV), an explosively replicating flavivirus, results in viral hemorrhagic disease characterized by cardiovascular shock and multi-organ failure. Unvaccinated populations experience 20 to 50% fatality. Few studies have examined the pathophysiological changes that occur in humans during YFV infection due to the sporadic nature and remote locations of outbreaks. Rhesus macaques are highly susceptible to YFV infection, providing a robust animal model to investigate host-pathogen interactions. In this study, we characterized disease progression as well as alterations in immune system homeostasis, cytokine production and gene expression in rhesus macaques infected with the virulent YFV strain DakH1279 (YFV-DakH1279). Following infection, YFV-DakH1279 replicated to high titers resulting in viscerotropic disease with ∼72% mortality. Data presented in this manuscript demonstrate for the first time that lethal YFV infection results in profound lymphopenia that precedes the hallmark changes in liver enzymes and that although tissue damage was noted in liver, kidneys, and lymphoid tissues, viral antigen was only detected in the liver. These observations suggest that additional tissue damage could be due to indirect effects of viral replication. Indeed, circulating levels of several cytokines peaked shortly before euthanasia. Our study also includes the first description of YFV-DakH1279-induced changes in gene expression within peripheral blood mononuclear cells 3 days post-infection prior to any clinical signs. These data show that infection with wild type YFV-DakH1279 or live-attenuated vaccine strain YFV-17D, resulted in 765 and 46 differentially expressed genes (DEGs), respectively. DEGs detected after YFV-17D infection were mostly associated with innate immunity, whereas YFV-DakH1279 infection resulted in dysregulation of genes associated with the development of immune response, ion metabolism, and apoptosis. Therefore, WT-YFV infection

  9. Pathophysiologic and Transcriptomic Analyses of Viscerotropic Yellow Fever in a Rhesus Macaque Model

    PubMed Central

    Engelmann, Flora; Josset, Laurence; Girke, Thomas; Park, Byung; Barron, Alex; Dewane, Jesse; Hammarlund, Erika; Lewis, Anne; Axthelm, Michael K.; Slifka, Mark K.; Messaoudi, Ilhem

    2014-01-01

    Infection with yellow fever virus (YFV), an explosively replicating flavivirus, results in viral hemorrhagic disease characterized by cardiovascular shock and multi-organ failure. Unvaccinated populations experience 20 to 50% fatality. Few studies have examined the pathophysiological changes that occur in humans during YFV infection due to the sporadic nature and remote locations of outbreaks. Rhesus macaques are highly susceptible to YFV infection, providing a robust animal model to investigate host-pathogen interactions. In this study, we characterized disease progression as well as alterations in immune system homeostasis, cytokine production and gene expression in rhesus macaques infected with the virulent YFV strain DakH1279 (YFV-DakH1279). Following infection, YFV-DakH1279 replicated to high titers resulting in viscerotropic disease with ∼72% mortality. Data presented in this manuscript demonstrate for the first time that lethal YFV infection results in profound lymphopenia that precedes the hallmark changes in liver enzymes and that although tissue damage was noted in liver, kidneys, and lymphoid tissues, viral antigen was only detected in the liver. These observations suggest that additional tissue damage could be due to indirect effects of viral replication. Indeed, circulating levels of several cytokines peaked shortly before euthanasia. Our study also includes the first description of YFV-DakH1279-induced changes in gene expression within peripheral blood mononuclear cells 3 days post-infection prior to any clinical signs. These data show that infection with wild type YFV-DakH1279 or live-attenuated vaccine strain YFV-17D, resulted in 765 and 46 differentially expressed genes (DEGs), respectively. DEGs detected after YFV-17D infection were mostly associated with innate immunity, whereas YFV-DakH1279 infection resulted in dysregulation of genes associated with the development of immune response, ion metabolism, and apoptosis. Therefore, WT-YFV infection

  10. Distinct gene expression profiles in peripheral blood mononuclear cells from patients infected with vaccinia virus, yellow fever 17D virus, or upper respiratory infections.

    PubMed

    Scherer, Christina A; Magness, Charles L; Steiger, Kathryn V; Poitinger, Nicholas D; Caputo, Christine M; Miner, Douglas G; Winokur, Patricia L; Klinzman, Donna; McKee, Janice; Pilar, Christine; Ward, Patricia A; Gillham, Martha H; Haulman, N Jean; Stapleton, Jack T; Iadonato, Shawn P

    2007-08-29

    Gene expression in human peripheral blood mononuclear cells was systematically evaluated following smallpox and yellow fever vaccination, and naturally occurring upper respiratory infection (URI). All three infections were characterized by the induction of many interferon stimulated genes, as well as enhanced expression of genes involved in proteolysis and antigen presentation. Vaccinia infection was also characterized by a distinct expression signature composed of up-regulation of monocyte response genes, with repression of genes expressed by B and T-cells. In contrast, the yellow fever host response was characterized by a suppression of ribosomal and translation factors, distinguishing this infection from vaccinia and URI. No significant URI-specific signature was observed, perhaps reflecting greater heterogeneity in the study population and etiological agents. Taken together, these data suggest that specific host gene expression signatures may be identified that distinguish one or a small number of virus agents.

  11. Development of a quantitative NS1-capture enzyme-linked immunosorbent assay for early detection of yellow fever virus infection.

    PubMed

    Ricciardi-Jorge, Taissa; Bordignon, Juliano; Koishi, Andrea; Zanluca, Camila; Mosimann, Ana Luiza; Duarte Dos Santos, Claudia Nunes

    2017-11-24

    Yellow fever is an arboviral disease that causes thousands of deaths every year in Africa and the Americas. However, few commercial diagnostic kits are available. Non-structural protein 1 (NS1) is an early marker of several flavivirus infections and is widely used to diagnose dengue virus (DENV) infection. Nonetheless, little is known about the dynamics of Yellow fever virus (YFV) NS1 expression and secretion, to encourage its use in diagnosis. To tackle this issue, we developed a quantitative NS1-capture ELISA specific for YFV using a monoclonal antibody and recombinant NS1 protein. This test was used to quantify NS1 in mosquito and human cell line cultures infected with vaccine and wild YFV strains. Our results showed that NS1 was detectable in the culture supernatants of both cell lines; however, a higher concentration was maintained as cell-associated rather than secreted into the extracellular milieu. A panel of 73 human samples was used to demonstrate the suitability of YFV NS1 as a diagnostic tool, resulting in 80% sensitivity, 100% specificity, a 100% positive predictive value and a 95.5% negative predictive value compared with RT-PCR. Overall, the developed NS1-capture ELISA showed potential as a promising assay for the detection of early YF infection.

  12. Localised transmission hotspots of a typhoid fever outbreak in the Democratic Republic of Congo.

    PubMed

    Ali, Engy; Bergh, Rafael Van Den; D'hondt, Rob; Kuma-Kuma, Donat; Weggheleire, Anja De; Baudot, Yves; Lambert, Vincent; Hunter, Paul; Zachariah, Rony; Maes, Peter

    2017-01-01

    In a semi-urban setting in the Democratic Republic of Congo, this study aims to understand the dynamic of a typhoid fever (TF) outbreak and to assess: a) the existence of hot spots for TF transmission and b) the difference between typhoid cases identified within those hot spots and the general population in relation to socio-demographic characteristics, sanitation practice, and sources of drinking water. This was a retrospective analysis of TF outbreaks in 2011 in Kikwit, DRC using microbiological analysis of water sources and a structured interview questionnaire. There were a total of 1430 reported TF cases. The outbreak's epidemic curve shows earliest and highest peak attack rates (AR) in three military camps located in Kikwit (Ebeya 3.2%; Ngubu 3.0%; and Nsinga 2.2%) compared to an average peak AR of 0.6% in other affected areas. A total 320 cases from the military camps and the high burden health areas were interviewed. Typhoid cases in the military camps shared a latrine with more than one family (P<0.02). All tap water sources in both the military camps and general population were found to be highly contaminated with faecal coliforms. The role of military camps in Kikwit as early hotspots of TF transmission was likely associated with lower sanitary and hygiene conditions. The proximity of camps to the general population might have been responsible for disseminating TF to the general population. Mapping of cases during an outbreak could be crucial to identify hot spots for transmission and institute corrective measures.

  13. Genetic structure and phylogeography of Aedes aegypti, the dengue and yellow-fever mosquito vector in Bolivia.

    PubMed

    Paupy, Christophe; Le Goff, Gilbert; Brengues, Cécile; Guerra, Mabel; Revollo, Jimmy; Barja Simon, Zaïra; Hervé, Jean-Pierre; Fontenille, Didier

    2012-08-01

    Between the 16th and 18th centuries, Aedes aegypti (Diptera: Culicidae), a mosquito native to Africa, invaded the Americas, where it was successively responsible for the emergence of yellow fever (YF) and dengue (DEN). The species was eradicated from numerous American countries in the mid-20th century, but re-invaded them in the 1970s and 1980s. Little is known about the precise identities of Ae. aegypti populations which successively thrived in South America, or their relation with the epidemiological changes in patterns of YF and DEN. We examined these questions in Bolivia, where Ae. aegypti, eradicated in 1943, re-appeared in the 1980s. We assessed the genetic variability and population genetics of Ae. aegypti samples in order to deduce their genetic structure and likely geographic origin. Using a 21-population set covering Bolivia, we analyzed the polymorphism at nine microsatellite loci and in two mitochondrial DNA regions (COI and ND4). Microsatellite markers revealed a significant genetic structure among geographic populations (F(ST)=0.0627, P<0.0001) in relation with the recent re-expansion of Ae. aegypti in Bolivia. Analysis of mtDNA sequences revealed the existence of two genetic lineages, one dominant lineage recovered throughout Bolivia, and the second restricted to rural localities in South Bolivia. Phylogenic analysis indicated that this minority lineage was related to West African Ae. aegypti specimens. In conclusion, our results suggested a temporal succession of Ae. aegypti populations in Bolivia, that potentially impacted the epidemiology of dengue and yellow fever. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Outbreak of Rift Valley fever affecting veterinarians and farmers in South Africa, 2008.

    PubMed

    Archer, Brett N; Weyer, Jacqueline; Paweska, Janusz; Nkosi, Deliwe; Leman, Patricia; Tint, Khin San; Blumberg, Lucille

    2011-04-01

    During 2008, Rift Valley fever (RVF) virus re-emerged in South Africa as focal outbreaks in several provinces. To investigate an outbreak affecting cattle farmers and farm workers, and the staff and students of a veterinary school, assess the prevalence of infection during the outbreak, document the clinical presentation of cases, and identify potential risk factors. We conducted a cross-sectional serological survey of exposed veterinarians and farmers, who were examined to determine the presence of current or recent illness. Blood specimens were collected for virus isolation, nucleic acid detection and serology. A subset was interviewed using a standardised questionnaire to obtain data on recent exposures and risk factors for infection. Of 53 participants potentially exposed to infected domestic ruminants, 15% had evidence of recent infection and 4% evidence of past exposure to the RVF virus. The prevalence of acute infection was 21% in veterinarians compared with 9% in farmers and farm workers. After a mean incubation period of 4.3 days, the most frequent symptoms experienced included myalgia (100%), headache (88%) and malaise (75%). No asymptomatic cases were identified. Transmission, by direct contact with infected animals was the major risk factor in these professional groups. Performing animal autopsies was significantly associated with acute infection (risk ratio 16.3, 95% confidence interval 2.3 - 114.2). Increased risks associated with veterinary practices highlight a need for the use of personal protective equipment, and identify veterinarians as a primary target group for future vaccination.

  15. Vaccination against yellow fever in French Guiana: The impact of educational level, negative beliefs and attitude towards vaccination.

    PubMed

    Koïvogui, Akoï; Carbunar, Aurel; Imounga, Laure-Manuella; Laruade, Christelle; Laube, Sylvaine

    Analyze the impact of educational level, negative beliefs and negative attitudes on the yellow fever vaccination coverage (YFVC). This analytical study involved a sample of 2763 people from 866 households. Educational status was described in six levels: No level (Respondent had never attended school), level-1 (respondent left before intermediate school), level-2 (Respondent attended intermediate school), level-3 (respondent attended high school), level-4 (Respondent attended university), Other level (When the level could not be determined). The Attitude towards vaccination was described in terms of person's availability to recommend vaccination to third. The relationships were analyzed by multivariate mixed logistic regression. Among the 2763 peoples, 2039 (73.8%) were vaccinated against yellow fever. People who left high school with or without the French baccalaureate were more likely to be vaccinated against YF than people without any diploma (OR = 1.4; p < 0.05). The probability of being vaccinated among people with negative attitudes was reduced by 40% (OR = 0.6; p < 0.05). Low level of education, negative beliefs and negative attitudes have significant impacts on YFVC. Negatives beliefs and attitudes result often from a major lack of information about the benefits of vaccination. This deficit is exacerbated in persons with low educational level. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Immune correlates of protection against yellow fever determined by passive immunization and challenge in the hamster model.

    PubMed

    Julander, Justin G; Trent, Dennis W; Monath, Thomas P

    2011-08-11

    Live, attenuated yellow fever (YF) 17D vaccine is highly efficacious but causes rare, serious adverse events resulting from active replication in the host and direct viral injury to vital organs. We recently reported development of a potentially safer β-propiolactone-inactivated whole virion YF vaccine (XRX-001), which was highly immunogenic in mice, hamsters, monkeys, and humans [10,11]. To characterize the protective efficacy of neutralizing antibodies stimulated by the inactivated vaccine, graded doses of serum from hamsters immunized with inactivated XRX-001 or live 17D vaccine were transferred to hamsters by the intraperitoneal (IP) route 24h prior to virulent, viscerotropic YF virus challenge. Neutralizing antibody (PRNT(50)) titers were determined in the sera of treated animals 4h before challenge and 4 and 21 days after challenge. Neutralizing antibodies were shown to mediate protection. Animals having 50% plaque reduction neutralization test (PRNT(50)) titers of ≥40 4h before challenge were completely protected from disease as evidenced by viremia, liver enzyme elevation, and protection against illness (weight change) and death. Passive titers of 10-20 were partially protective. Immunization with the XRX-001 vaccine stimulated YF neutralizing antibodies that were equally effective (based on dose response) as antibodies stimulated by live 17D vaccine. The results will be useful in defining the level of seroprotection in clinical studies of new yellow fever vaccines. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Pre-Clinical Efficacy and Safety of Experimental Vaccines Based on Non-Replicating Vaccinia Vectors against Yellow Fever

    PubMed Central

    Schäfer, Birgit; Holzer, Georg W.; Joachimsthaler, Alexandra; Coulibaly, Sogue; Schwendinger, Michael; Crowe, Brian A.; Kreil, Thomas R.; Barrett, P. Noel; Falkner, Falko G.

    2011-01-01

    Background Currently existing yellow fever (YF) vaccines are based on the live attenuated yellow fever virus 17D strain (YFV-17D). Although, a good safety profile was historically attributed to the 17D vaccine, serious adverse events have been reported, making the development of a safer, more modern vaccine desirable. Methodology/Principal Findings A gene encoding the precursor of the membrane and envelope (prME) protein of the YFV-17D strain was inserted into the non-replicating modified vaccinia virus Ankara and into the D4R-defective vaccinia virus. Candidate vaccines based on the recombinant vaccinia viruses were assessed for immunogenicity and protection in a mouse model and compared to the commercial YFV-17D vaccine. The recombinant live vaccines induced γ-interferon-secreting CD4- and functionally active CD8-T cells, and conferred full protection against lethal challenge already after a single low immunization dose of 105 TCID50. Surprisingly, pre-existing immunity against wild-type vaccinia virus did not negatively influence protection. Unlike the classical 17D vaccine, the vaccinia virus-based vaccines did not cause mortality following intracerebral administration in mice, demonstrating better safety profiles. Conclusions/Significance The non-replicating recombinant YF candidate live vaccines induced a broad immune response after single dose administration, were effective even in the presence of a pre-existing immunity against vaccinia virus and demonstrated an excellent safety profile in mice. PMID:21931732

  18. Relationship of climate, geography, and geology to the incidence of Rift Valley fever in Kenya during the 2006-2007 outbreak.

    PubMed

    Hightower, Allen; Kinkade, Carl; Nguku, Patrick M; Anyangu, Amwayi; Mutonga, David; Omolo, Jared; Njenga, M Kariuki; Feikin, Daniel R; Schnabel, David; Ombok, Maurice; Breiman, Robert F

    2012-02-01

    We estimated Rift Valley fever (RVF) incidence as a function of geological, geographical, and climatological factors during the 2006-2007 RVF epidemic in Kenya. Location information was obtained for 214 of 340 (63%) confirmed and probable RVF cases that occurred during an outbreak from November 1, 2006 to February 28, 2007. Locations with subtypes of solonetz, calcisols, solonchaks, and planosols soil types were highly associated with RVF occurrence during the outbreak period. Increased rainfall and higher greenness measures before the outbreak were associated with increased risk. RVF was more likely to occur on plains, in densely bushed areas, at lower elevations, and in the Somalia acacia ecological zone. Cases occurred in three spatial temporal clusters that differed by the date of associated rainfall, soil type, and land usage.

  19. Diphtheria, tetanus, poliomyelitis, yellow fever and hepatitis B seroprevalence among HIV1-infected migrants. Results from the ANRS VIHVO vaccine sub-study.

    PubMed

    Mullaert, Jimmy; Abgrall, Sophie; Lele, Nathalie; Batteux, Frederic; Slama, Lilia Ben; Meritet, Jean-Francois; Lebon, Pierre; Bouchaud, Olivier; Grabar, Sophie; Launay, Odile

    2015-09-11

    Few data are available on the seroprotection status of HIV1-infected patients with respect to vaccine-preventable diseases. To describe, in a population of HIV1-infected migrants on stable, effective ART therapy, the seroprevalence of diphtheria, poliomyelitis, tetanus, yellow fever antibodies and serostatus for hepatitis B, and to identify factors associated with seroprotection. Vaccine responses against diphtheria, tetanus, poliomyelitis and yellow fever were also studied. Sub-Saharan African patients participating in the ANRS-VIHVO cohort were enrolled prior to travel to their countries of origin. Serologic analyses were performed in a central laboratory before and after the trip. Univariate and multivariate logistic regression was used to identify factors associated with initial seroprotection. 250 patients (99 men and 151 women) were included in the seroprevalence study. Median age was 45 years (IQR 39-52), median CD4 cell count was 440/μL (IQR 336-571), and 237 patients (95%) had undetectable HIV1 viral load. The initial seroprevalence rates were 69.0% (95%CI 63.2-74.7) for diphtheria, 70.7% (95%CI 65.0-76.3) for tetanus, and 85.9% (95%CI 81.6-90.2) for yellow fever. Only 64.4% (95%CI 58.5-70.3) of patients had protective antibody titers against all three poliomyelitis vaccine strains before travel. No serological markers of hepatitis B were found in 18.6% of patients (95%CI 13.7-23.3). Patient declaration of prior vaccination was the only factor consistently associated with initial seroprotection. We found a low prevalence of seroprotection against diphtheria, poliomyelitis, tetanus and hepatitis B. HIV infected migrants living in France and traveling to their native countries need to have their vaccine schedule completed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Global nursing in an Ebola viral haemorrhagic fever outbreak: before, during and after deployment

    PubMed Central

    von Strauss, Eva; Paillard-Borg, Stéphanie; Holmgren, Jessica; Saaristo, Panu

    2017-01-01

    ABSTRACT Background: Nurses are on the forefront and play a key role in global disaster responses. Nevertheless, they are often not prepared for the challenges they are facing and research is scarce regarding the nursing skills required for first responders during a disaster situation. Objectives: To investigate how returnee nursing staff experienced deployment before, during and after having worked for the Red Cross at an Ebola Treatment Center in Kenema, West Africa, and to supply knowledge on how to better prepare and support staff for viral haemorrhagic fever outbreaks. Methods: A descriptive, cross-sectional approach. Questionnaires were administered to nurses having worked with patients suffering from Ebola in 2014 and 2015. Data collection covered aspects of pre-, during and post-deployment on clinical training, personal health, stress management, leadership styles, socio-cultural exposure and knowledge transfer, as well as attitudes from others. Data was analysed using both quantitative and qualitative methods. Results: Response-rate was 88%: forty-four nurses from 15 different countries outside West Africa answered the questionnaire. The respondents identified the following needs for improvement: increased mental health and psychosocial support and hands-on coping strategies with focus on pre- and post-deployment; more pre-deployment task-oriented clinical training; and workload reduction, as exhaustion is a risk for safety. Conclusions: This study supplies knowledge on how to better prepare health care staff for future viral haemorrhagic fever outbreaks and other disasters. Participants were satisfied with their pre-deployment physical health preparation, whereas they stressed the importance of mental health support combined with psychosocial support after deployment. Furthermore, additional pre-clinical training was requested. PMID:29017025

  1. Diagnosis and genotyping of African swine fever viruses from 2015 outbreaks in Zambia.

    PubMed

    Thoromo, Jonas; Simulundu, Edgar; Chambaro, Herman M; Mataa, Liywalii; Lubaba, Caesar H; Pandey, Girja S; Takada, Ayato; Misinzo, Gerald; Mweene, Aaron S

    2016-04-29

    In early 2015, a highly fatal haemorrhagic disease of domestic pigs resembling African swine fever (ASF) occurred in North Western, Copperbelt, and Lusaka provinces of Zambia. Molecular diagnosis by polymerase chain reaction targeting specific amplification of p72 (B646L) gene of ASF virus (ASFV) was conducted. Fourteen out of 16 domestic pigs from the affected provinces were found to be positive for ASFV. Phylogenetic analyses based on part of the p72 and the complete p54 (E183L) genes revealed that all the ASFVs detected belonged to genotypes I and Id, respectively. Additionally, epidemiological data suggest that the same ASFV spread from Lusaka to other provinces possibly through uncontrolled and/or illegal pig movements. Although the origin of the ASFV that caused outbreaks in domestic pigs in Zambia could not be ascertained, it appears likely that the virus may have emerged from within the country or region, probably from a sylvatic cycle. It is recommended that surveillance of ASF, strict biosecurity, and quarantine measures be imposed in order to prevent further spread and emergence of new ASF outbreaks in Zambia.

  2. Colonoscopic findings and management of patients with outbreak typhoid fever presenting with lower gastrointestinal bleeding.

    PubMed

    Shaikhani, Mohammad A R; Husein, Hiwa A B; Karbuli, Taha A; Mohamed, Mohamed Abdulrahman

    2013-09-01

    Lower gastrointestinal bleeding (LGIB) along with intestinal perforation is a well-known complication of typhoid fever. Reports of colonoscopic appearance and intervention of typhoid perforation involve only few cases. This series reports the colonoscopic findings and the role of colonoscopic hemostatic interventions in controlling the bleeding ileocolonic lesions. During the typhoid fever outbreak in Sulaymaniyah City in Iraqi Kurdistan Region, we received 52 patients with LGIB manifesting as fresh bleeding per rectum or melena. We performed total colonoscopy with ileal intubation for all cases. The findings were recorded and endoscopic hemostatic intervention with adrenaline-saline injection and argon plasma coagulation was applied to actively bleeding lesion. These patients were young, 11-30 years of age, with female preponderance. Blood culture was positive in 50 %. Colonoscopic findings were mostly located in the ileocecal region, although other areas of the colon were involved in many cases. Twenty-four percent of the cases required endoscopic hemostatic intervention by adrenaline injection with argon plasma coagulation which was effective in all patients except one who died in spite of surgical intervention in addition of endoscopic hemostasis. Dual endoscopic hemostatic intervention can be a safe and effective management option for patients with LGIB due to typhoid fever.

  3. Travel Characteristics and Yellow Fever Vaccine Usage Among US Global TravEpiNet Travelers Visiting Countries with Risk of Yellow Fever Virus Transmission, 2009–2011

    PubMed Central

    Jentes, Emily S.; Han, Pauline; Gershman, Mark D.; Rao, Sowmya R.; LaRocque, Regina C.; Staples, J. Erin; Ryan, Edward T.

    2013-01-01

    Yellow fever (YF) vaccine-associated serious adverse events and changing YF epidemiology have challenged healthcare providers to vaccinate only travelers whose risk of YF during travel is greater than their risk of adverse events. We describe the travel characteristics and YF vaccine use among US travelers visiting Global TravEpiNet clinics from January of 2009 to March of 2011. Of 16,660 travelers, 5,588 (34%) had itineraries to areas with risk of YF virus transmission. Of those travelers visiting one country with YF risk (N = 4,517), 71% were vaccinated at the visit, and 20% were presumed to be immune from prior vaccination. However, travelers visiting friends and relatives (odds ratio [OR] = 2.57, 95% confidence interval [95% CI] = 1.27–5.22) or going to Nigeria (OR = 3.01, 95% CI = 1.37–6.62) were significantly more likely to decline vaccination. To optimize YF vaccine use, clinicians should discuss an individual's risk–benefit assessment of vaccination and close knowledge gaps regarding vaccine use among at-risk populations. PMID:23458961

  4. Rift Valley Fever Virus

    USDA-ARS?s Scientific Manuscript database

    Rift Valley fever virus (RVFV) is a mosquito-transmitted virus or arbovirus that is endemic in sub-Saharan Africa. In the last decade, Rift Valley fever (RVF) outbreaks have resulted in loss of human and animal life, as well as had significant economic impact. The disease in livestock is primarily a...

  5. Chemosensory responses to the repellent nepeta essential oil and its major component nepetalactone by the yellow fever mosquito, aedes aegypti, a vector of zika virus

    USDA-ARS?s Scientific Manuscript database

    Nepeta essential oil (Neo) (catnip) and its major component, nepetalactone, have long been known to repel insects including mosquitoes. However, the neural mechanisms through which these repellents are detected by mosquitoes, including the yellow fever mosquito Aedes aegypti, an important vector of...

  6. An Outbreak of Food-Borne Typhoid Fever Due to Salmonella enterica Serotype Typhi in Japan Reported for the First Time in 16 Years

    PubMed Central

    Kobayashi, Tetsuro; Kutsuna, Satoshi; Hayakawa, Kayoko; Kato, Yasuyuki; Ohmagari, Norio; Uryu, Hideko; Yamada, Ritsuko; Kashiwa, Naoyuki; Nei, Takahito; Ehara, Akihito; Takei, Reiko; Mori, Nobuaki; Yamada, Yasuhiro; Hayasaka, Tomomi; Kagawa, Narito; Sugawara, Momoko; Suzaki, Ai; Takahashi, Yuno; Nishiyama, Hiroyuki; Morita, Masatomo; Izumiya, Hidemasa; Ohnishi, Makoto

    2016-01-01

    For the first time in 16 years, a food-borne outbreak of typhoid fever due to Salmonella enterica serotype Typhi was reported in Japan. Seven patients consumed food in an Indian buffet at a restaurant in the center of Tokyo, while one was a Nepali chef in the restaurant, an asymptomatic carrier and the implicated source of this outbreak. The multiple-locus variable-number tandem repeat analysis showed 100% consistency in the genomic sequence for five of the eight cases. PMID:26621565

  7. Large genetic differentiation and low variation in vector competence for dengue and yellow fever viruses of Aedes albopictus from Brazil, the United States, and the Cayman Islands.

    PubMed

    Lourenço de Oliveira, Ricardo; Vazeille, Marie; de Filippis, Ana Maria Bispo; Failloux, Anna-Bella

    2003-07-01

    We conducted a population genetic analysis of Aedes albopictus collected from 20 sites in Brazil, the United States (Florida, Georgia, and Illinois), and the Cayman Islands. Using isoenzyme analysis, we examined genetic diversity and patterns of gene flow. High genetic differentiation was found among Brazilian samples, and between them and North American samples. Regression analysis of genetic differentiation according to geographic distances indicated that Ae. albopictus samples from Florida were genetically isolated by distance. Infection rates with dengue and yellow fever viruses showed greater differences between two Brazilian samples than between the two North American samples or between a Brazilian sample and a North American sample. Introductions and establishments of new Ae. albopictus populations in the Americas are still in progress, shaping population genetic composition and potentially modifying both dengue and yellow fever transmission patterns.

  8. Protective and immunological behavior of chimeric yellow fever dengue vaccine.

    PubMed

    Halstead, Scott B; Russell, Philip K

    2016-03-29

    Clinical observations from the third year of the Sanofi Pasteur chimeric yellow fever dengue tetravalent vaccine (CYD) trials document both protection and vaccination-enhanced dengue disease among vaccine recipients. Children who were 5 years-old or younger when vaccinated experienced a DENV disease resulting in hospitalization at 5 times the rate of controls. On closer inspection, hospitalized cases among vaccinated seropositives, those at highest risk to hospitalized disease accompanying a dengue virus (DENV) infection, were greatly reduced by vaccination. But, seronegative individuals of all ages after being vaccinated were only modestly protected from mild to moderate disease throughout the entire observation period despite developing neutralizing antibodies at high rates. Applying a simple epidemiological model to the data, vaccinated seronegative individuals of all ages were at increased risk of developing hospitalized disease during a subsequent wild type DENV infection. The etiology of disease in placebo and vaccinated children resulting in hospitalization during a DENV infection, while clinically similar are of different origin. The implications of the observed mixture of DENV protection and enhanced disease in CYD vaccinees are discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Three-dimensional visualization of cultural clusters in the 1878 yellow fever epidemic of New Orleans

    PubMed Central

    Curtis, Andrew J

    2008-01-01

    Background An epidemic may exhibit different spatial patterns with a change in geographic scale, with each scale having different conduits and impediments to disease spread. Mapping disease at each of these scales often reveals different cluster patterns. This paper will consider this change of geographic scale in an analysis of yellow fever deaths for New Orleans in 1878. Global clustering for the whole city, will be followed by a focus on the French Quarter, then clusters of that area, and finally street-level patterns of a single cluster. The three-dimensional visualization capabilities of a GIS will be used as part of a cluster creation process that incorporates physical buildings in calculating mortality-to-mortality distance. Including nativity of the deceased will also capture cultural connection. Results Twenty-two yellow fever clusters were identified for the French Quarter. These generally mirror the results of other global cluster and density surfaces created for the entire epidemic in New Orleans. However, the addition of building-distance, and disease specific time frame between deaths reveal that disease spread contains a cultural component. Same nativity mortality clusters emerge in a similar time frame irrespective of proximity. Italian nativity mortalities were far more densely grouped than any of the other cohorts. A final examination of mortalities for one of the nativity clusters reveals that further sub-division is present, and that this pattern would only be revealed at this scale (street level) of investigation. Conclusion Disease spread in an epidemic is complex resulting from a combination of geographic distance, geographic distance with specific connection to the built environment, disease-specific time frame between deaths, impediments such as herd immunity, and social or cultural connection. This research has shown that the importance of cultural connection may be more important than simple proximity, which in turn might mean traditional

  10. Three-dimensional visualization of cultural clusters in the 1878 yellow fever epidemic of New Orleans.

    PubMed

    Curtis, Andrew J

    2008-08-22

    An epidemic may exhibit different spatial patterns with a change in geographic scale, with each scale having different conduits and impediments to disease spread. Mapping disease at each of these scales often reveals different cluster patterns. This paper will consider this change of geographic scale in an analysis of yellow fever deaths for New Orleans in 1878. Global clustering for the whole city, will be followed by a focus on the French Quarter, then clusters of that area, and finally street-level patterns of a single cluster. The three-dimensional visualization capabilities of a GIS will be used as part of a cluster creation process that incorporates physical buildings in calculating mortality-to-mortality distance. Including nativity of the deceased will also capture cultural connection. Twenty-two yellow fever clusters were identified for the French Quarter. These generally mirror the results of other global cluster and density surfaces created for the entire epidemic in New Orleans. However, the addition of building-distance, and disease specific time frame between deaths reveal that disease spread contains a cultural component. Same nativity mortality clusters emerge in a similar time frame irrespective of proximity. Italian nativity mortalities were far more densely grouped than any of the other cohorts. A final examination of mortalities for one of the nativity clusters reveals that further sub-division is present, and that this pattern would only be revealed at this scale (street level) of investigation. Disease spread in an epidemic is complex resulting from a combination of geographic distance, geographic distance with specific connection to the built environment, disease-specific time frame between deaths, impediments such as herd immunity, and social or cultural connection. This research has shown that the importance of cultural connection may be more important than simple proximity, which in turn might mean traditional quarantine measures should be

  11. Jail fever (epidemic typhus) outbreak in Burundi.

    PubMed

    Raoult, D; Roux, V; Ndihokubwayo, J B; Bise, G; Baudon, D; Marte, G; Birtles, R

    1997-01-01

    We recently investigated a suspected outbreak of epidemic typhus in a jail in Burundi. We tested sera of nine patients by microimmunofluorescence for antibodies to Rickettsia prowazekii and Rickettsia typhi. We also amplified and sequenced from lice gene portions specific for two R. prowazekii proteins: the gene encoding for citrate synthase and the gene encoding for the rickettsial outer membrane protein. All patients exhibited antibodies specific for R. prowazekii. Specific gene sequences were amplified in two lice from one patient. The patients had typical clinical manifestations, and two died. Molecular techniques provided a convenient and reliable means of examining lice and confirming this outbreak. The jail-associated outbreak predates an extensive ongoing outbreak of louse-borne typhus in central eastern Africa after civil war and in refugee camps in Rwanda, Burundi (1), and Zaire.

  12. Jail fever (epidemic typhus) outbreak in Burundi.

    PubMed Central

    Raoult, D.; Roux, V.; Ndihokubwayo, J. B.; Bise, G.; Baudon, D.; Marte, G.; Birtles, R.

    1997-01-01

    We recently investigated a suspected outbreak of epidemic typhus in a jail in Burundi. We tested sera of nine patients by microimmunofluorescence for antibodies to Rickettsia prowazekii and Rickettsia typhi. We also amplified and sequenced from lice gene portions specific for two R. prowazekii proteins: the gene encoding for citrate synthase and the gene encoding for the rickettsial outer membrane protein. All patients exhibited antibodies specific for R. prowazekii. Specific gene sequences were amplified in two lice from one patient. The patients had typical clinical manifestations, and two died. Molecular techniques provided a convenient and reliable means of examining lice and confirming this outbreak. The jail-associated outbreak predates an extensive ongoing outbreak of louse-borne typhus in central eastern Africa after civil war and in refugee camps in Rwanda, Burundi (1), and Zaire. PMID:9284381

  13. A typhoid fever outbreak in a slum of South Dumdum municipality, West Bengal, India, 2007: evidence for foodborne and waterborne transmission.

    PubMed

    Bhunia, Rama; Hutin, Yvan; Ramakrishnan, Ramachandran; Pal, Nishith; Sen, Tapas; Murhekar, Manoj

    2009-04-27

    In April 2007, a slum of South Dumdum municipality, West Bengal reported an increase in fever cases. We investigated to identify the agent, the source and to propose recommendations. We defined a suspected case of typhoid fever as occurrence of fever for > or = one week among residents of ward 1 of South Dumdum during February - May 2007. We searched for suspected cases in health care facilities and collected blood specimens. We described the outbreak by time, place and person. We compared probable cases (Widal positive > or = 1:80) with neighbourhood-matched controls. We assessed the environment and collected water specimens. We identified 103 suspected cases (Attack rate: 74/10,000, highest among 5-14 years old group, no deaths). Salmonella (enterica) Typhi was isolated from one of four blood specimens and 65 of 103 sera were > or = 1:80 Widal positive. The outbreak started on 13 February, peaked twice during the last week of March and second week of April and lasted till 27 April. Suspected cases clustered around three public taps. Among 65 probable cases and 65 controls, eating milk products from a sweet shop (Matched odds ratio [MOR]: 6.2, 95% confidence interval [CI]: 2.4-16, population attributable fraction [PAF]: 53%) and drinking piped water (MOR: 7.3, 95% CI: 2.5-21, PAF-52%) were associated with illness. The sweet shop food handler suffered from typhoid in January. The pipelines of intermittent non-chlorinated water supply ran next to an open drain connected with sewerage system and water specimens showed faecal contamination. The investigation suggested that an initial foodborne outbreak of typhoid led to the contamination of the water supply resulting in a secondary, waterborne wave. We educated the food handler, repaired the pipelines and ensured chlorination of the water.

  14. Phylogeographic Reconstruction of African Yellow Fever Virus Isolates Indicates Recent Simultaneous Dispersal into East and West Africa

    PubMed Central

    Beck, Andrew; Guzman, Hilda; Li, Li; Ellis, Brett; Tesh, Robert B.; Barrett, Alan D. T.

    2013-01-01

    Yellow fever virus (YFV) is a mosquito-borne flavivirus that is a major public health problem in tropical areas of Africa and South America. There have been detailed studies on YFV ecology in West Africa and South America, but current understanding of YFV circulation on the African continent is incomplete. This inadequacy is especially notable for East and Central Africa, for which the unpredictability of human outbreaks is compounded by limitations in both historical and present surveillance efforts. Sparse availability of nucleotide sequence data makes it difficult to investigate the dispersal of YFV in these regions of the continent. To remedy this, we constructed Bayesian phylogenetic and geographic analyses utilizing 49 partial genomic sequences to infer the structure of YFV divergence across the known range of the virus on the African continent. Relaxed clock analysis demonstrated evidence for simultaneous divergence of YFV into east and west lineages, a finding that differs from previous hypotheses of YFV dispersal from reservoirs located on edges of the endemic range. Using discrete and continuous geographic diffusion models, we provide detailed structure of YFV lineage diversity. Significant transition links between extant East and West African lineages are presented, implying connection between areas of known sylvatic cycling. The results of demographic modeling reinforce the existence of a stably maintained population of YFV with spillover events into human populations occurring periodically. Geographically distinct foci of circulation are reconstructed, which have significant implications for studies of YFV ecology and emergence of human disease. We propose further incorporation of Bayesian phylogeography into formal GIS analyses to augment studies of arboviral disease. PMID:23516640

  15. Relationship of Climate, Geography, and Geology to the Incidence of Rift Valley Fever in Kenya during the 2006–2007 Outbreak

    PubMed Central

    Hightower, Allen; Kinkade, Carl; Nguku, Patrick M.; Anyangu, Amwayi; Mutonga, David; Omolo, Jared; Njenga, M. Kariuki; Feikin, Daniel R.; Schnabel, David; Ombok, Maurice; Breiman, Robert F.

    2012-01-01

    We estimated Rift Valley fever (RVF) incidence as a function of geological, geographical, and climatological factors during the 2006–2007 RVF epidemic in Kenya. Location information was obtained for 214 of 340 (63%) confirmed and probable RVF cases that occurred during an outbreak from November 1, 2006 to February 28, 2007. Locations with subtypes of solonetz, calcisols, solonchaks, and planosols soil types were highly associated with RVF occurrence during the outbreak period. Increased rainfall and higher greenness measures before the outbreak were associated with increased risk. RVF was more likely to occur on plains, in densely bushed areas, at lower elevations, and in the Somalia acacia ecological zone. Cases occurred in three spatial temporal clusters that differed by the date of associated rainfall, soil type, and land usage. PMID:22302875

  16. [Marburg and Ebola hemorrhagic fevers--pathogens, epidemiology and therapy].

    PubMed

    Stock, Ingo

    2014-09-01

    Marburg and Ebola hemorrhagic fevers are severe, systemic viral diseases affecting humans and non-human primates. They are characterized by multiple symptoms such as hemorrhages, fever, headache, muscle and abdominal pain, chills, sore throat, nausea, vomiting and diarrhea. Elevated liver-associated enzyme levels and coagulopathy are also associated with these diseases. Marburg and Ebola hemorrhagic fevers are caused by (Lake victoria) Marburg virus and different species of Ebola viruses, respectively. They are enveloped, single-stranded RNA viruses and belong to the family of filoviridae. Case fatality rates of filovirus disease outbreaks are among the highest reported for any human pathogen, ranging from 25 to 90% or more. Outbreaks of Marburg and Ebola hemorrhagic fever occur in certain regions of equatorial Africa at irregular intervals. Since 2000, the number of outbreaks has increased. In 2014, the biggest outbreak of a filovirus-induced hemorrhagic fever that has been documented so far occurred from March to July 2014 in Guinea, Sierra Leone, Liberia and Nigeria. The outbreak was caused by a new variant of Zaire Ebola-Virus, affected more than 2600 people (stated 20 August) and was associated with case-fatality rates of up to 67% (Guinea). Treatment of Marburg and Ebola hemorrhagic fevers is symptomatic and supportive, licensed antiviral agents are currently not available. Recently, BCX4430, a promising synthetic adenosine analogue with high in vitro and in vivo activity against filoviruses and other RNA viruses, has been described. BCX4430 inhibits viral RNA polymerase activity and protects cynomolgus macaques from Marburg virus infection when administered as late as 48 hours after infection. Nucleic acid-based products, recombinant vaccines and antibodies appear to be less suitable for the treatment of Marburg and Ebola hemorrhagic fevers.

  17. Modifiable risk factors for typhoid intestinal perforations during a large outbreak of typhoid fever, Kampala Uganda, 2015.

    PubMed

    Bulage, Lilian; Masiira, Ben; Ario, Alex R; Matovu, Joseph K B; Nsubuga, Peter; Kaharuza, Frank; Nankabirwa, Victoria; Routh, Janell; Zhu, Bao-Ping

    2017-09-25

    Between January and June, 2015, a large typhoid fever outbreak occurred in Kampala, Uganda, with 10,230 suspected cases. During the outbreak, area surgeons reported a surge in cases of typhoid intestinal perforation (TIP), a complication of typhoid fever. We conducted an investigation to characterize TIP cases and identify modifiable risk factors for TIP. We defined a TIP case as a physician-diagnosed typhoid patient with non-traumatic terminal ileum perforation. We identified cases by reviewing medical records at all five major hospitals in Kampala from 2013 to 2015. In a matched case-control study, we compared potential risk factors among TIP cases and controls; controls were typhoid patients diagnosed by TUBEX TF, culture, or physician but without TIP, identified from the outbreak line-list and matched to cases by age, sex and residence. Cases and controls were interviewed using a standard questionnaire from 1st -23rd December 2015. We used conditional logistic regression to assess risk factors for TIP and control for confounding. Of the 88 TIP cases identified during 2013-2015, 77% (68/88) occurred between January and June, 2015; TIPs sharply increased in January and peaked in March, coincident with the typhoid outbreak. The estimated risk of TIP was 6.6 per 1000 suspected typhoid infections (68/10,230). The case-fatality rate was 10% (7/68). Cases sought care later than controls; Compared with 29% (13/45) of TIP cases and 63% (86/137) of controls who sought treatment within 3 days of onset, 42% (19/45) of cases and 32% (44/137) of controls sought treatment 4-9 days after illness onset (OR adj  = 2.2, 95%CI = 0.83-5.8), while 29% (13/45) of cases and 5.1% (7/137) of controls sought treatment ≥10 days after onset (OR adj  = 11, 95%CI = 1.9-61). 68% (96/141) of cases and 23% (23/100) of controls had got treatment before being treated at the treatment centre (OR adj  = 9.0, 95%CI = 1.1-78). Delay in seeking treatment increased the risk of TIPs

  18. Persistence of impaired health status of Q fever patients 4 years after the first Dutch outbreak.

    PubMed

    Limonard, G J M; Peters, J B; Besselink, R; Groot, C A R; Dekhuijzen, P N R; Vercoulen, J H; Nabuurs-Franssen, M H

    2016-04-01

    A significant proportion of Q fever patients from the first Dutch Q fever outbreak in 2007 showed impairment in health status up to 1 year after infection. Interested in whether this decrease in health status persisted, we set out to determine the health status in the same cohort of patients, 4 years after primary infection and to compare health status scores at the individual patient level between 1 and 4 years follow-up. Health status was assessed with the Nijmegen Clinical Screening Instrument (NCSI). Patients were serologically tested to exclude patients with possible, probable or proven chronic Q fever. Results on the NCSI sub-domains at group level [2008 (n = 54) and 2011 (n = 46)] showed a persistent significant percentage of patients exhibiting clinically relevant ('severe') scores for all NCSI sub-domains. After 4 years, undue fatigue was present in 46% and exactly half of all patients experienced a severely impaired general quality of life. Patients with NCSI scores available in both 2008 and 2011 (n = 37) showed no difference in all sub-domain scores, except for a small decrease in dyspnoea emotions in 2011. In this group, a significant proportion of patients either improved or worsened in one or more sub-domains of health status. We conclude that at the group level, health status of Q fever patients remained impaired 4 years after primary infection. At the individual patient level, health status may change.

  19. Disease Outbreaks Caused by Water.

    ERIC Educational Resources Information Center

    Craun, Gunther F.

    1978-01-01

    Presents a literature review of the disease outbreaks caused by drinking polluted water, covering publications of 1976-77. Some of the waterborn outbreaks included are: (1) cholera; (2) gastroenteritis; (3) giardiasis; and (4) typhoid fever and salmonellosis. A list of 66 references is also presented. (HM)

  20. Gustatory receptor neuron responds to DEET and other insect repellents in the yellow-fever mosquito, Aedes aegypti

    NASA Astrophysics Data System (ADS)

    Sanford, Jillian L.; Shields, Vonnie D. C.; Dickens, Joseph C.

    2013-03-01

    Three gustatory receptor neurons were characterized for contact chemoreceptive sensilla on the labella of female yellow-fever mosquitoes, Aedes aegypti. The neuron with the smallest amplitude spike responded to the feeding deterrent, quinine, as well as N, N-diethyl-3-methylbenzamide and other insect repellents. Two other neurons with differing spikes responded to salt (NaCl) and sucrose. This is the first report of a gustatory receptor neuron specific for insect repellents in mosquitoes and may provide a tool for screening chemicals to discover novel or improved feeding deterrents and repellents for use in the management of arthropod disease vectors.