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Sample records for acerca del dengue

  1. Acerca del moho

    EPA Pesticide Factsheets

    El moho forma parte del medio ambiente natural. Afuera del hogar, el moho juega un papel en la naturaleza al desintegrar materias organicas tales como las hojas que se han caido o los arboles muertos. El moho puede crecer adentro del hogar cuando las espor

  2. Dengue

    MedlinePlus

    ... Testing Epidemiologists Journalists Dengue Branch News Dengue and Climate Dengue Update About CDC's Dengue Branch Dengue in ... Mosquito Life-Cycle Mosquito Aquatic Habitats Dengue And Climate Clinical/Laboratory Guidance Clinical Guidance Laboratory Guidance Real- ...

  3. Dengue

    MedlinePlus

    Dengue is an infection caused by a virus. You can get it if an infected mosquito bites you. Dengue does not spread from person to person. It ... the world. Outbreaks occur in the rainy season. Dengue is rare in the United States. Symptoms include ...

  4. Dengue and Severe Dengue

    MedlinePlus

    ... serotypes increase the risk of developing severe dengue. Global burden of dengue The incidence of dengue has ... accumulation, respiratory distress, severe bleeding, or organ impairment. Warning signs occur 3–7 days after the first ...

  5. Actitudes de los candidatos y maestros de ciencias en servicio acerca del uso de las herramientas computadorizadas en las clases de ciencias

    NASA Astrophysics Data System (ADS)

    Bayuelo, Ezequiel

    Este estudio examino y comparo las actitudes de los candidatos a maestros de ciencias y los maestros de ciencias en servicio acerca de la utilizacion de las herramientas computadorizadas en las clases de ciencias. Tambien identifico y diferencio el uso que ellos dan a estas herramientas en las clases de ciencias. Este estudio presenta un diseno descriptivo exploratorio. Constituyeron la muestra trescientos diez sujetos que fueron candidatos a maestros de ciencias o maestros de ciencias en servicio. Para recoger los datos se construyo y valido un cuestionario de treinta y un itemes. Se utilizaron las pruebas estadisticas no parametricas Kruskal Wallis y Chi-cuadrado (test de homogeneidad) para establecer las diferencias entre las actitudes de los sujetos con relacion al uso de las herramientas computadorizadas en las clases de ciencias. Los hallazgos evidenciaron que son positivas y muy parecidas las actitudes de los candidatos a maestros y maestros en servicio hacia el uso de las herramientas computadorizadas. No hubo diferencias entre los candidatos y maestros en servicio en terminos de las actitudes de confianza y empatia hacia el uso de las herramientas computadorizadas en las clases de ciencias. En aspectos como el uso del banco de datos bibliografico Eric y el uso de las herramientas computadorizadas en actividades educativas como explorar conceptos, conceptuar, aplicar lo aprendido y hacer asignaciones hubo diferencias estadisticamente significativas entre los candidatos y los maestros en servicio. Al comparar las frecuencias observadas con las esperadas hubo mas maestros en servicio y menos candidatos que indicaron usar el anterior banco de datos y las herramientas computadorizadas en las mencionadas actividades educativas.

  6. Dengue encephalitis

    PubMed Central

    Borawake, Kapil; Prayag, Parikshit; Wagh, Atul; Dole, Swati

    2011-01-01

    We report a case of dengue fever with features of encephalitis. The diagnosis of dengue was confirmed by the serum antibodies to dengue and the presence of a dengue antigen in the cerebrospinal fluid. This patient had characteristic magnetic resonance imaging brain findings, mainly involving the bilateral thalami, with hemorrhage. Dengue is not primarily a neurotropic virus and encephalopathy is a common finding in Dengue. Hence various other etiological possibilities were considered before concluding this as a case of Dengue encephalitis. This case explains the importance of considering the diagnosis of dengue encephalitis in appropriate situations. PMID:22013316

  7. Dengue Fever

    MedlinePlus

    ... away from areas that have a dengue fever epidemic, the risk of contracting dengue fever is small for international travelers./p> Reviewed by: Elana ... Transfusions Cholera West Nile Virus First Aid: Vomiting Are Insect ...

  8. Expanded Dengue.

    PubMed

    Kadam, D B; Salvi, Sonali; Chandanwale, Ajay

    2016-07-01

    The World Health Organization (WHO) has coined the term expanded dengue to describe cases which do not fall into either dengue shock syndrome or dengue hemorrhagic fever. This has incorporated several atypical findings of dengue. Dengue virus has not been enlisted as a common etiological agent in several conditions like encephalitis, Guillain Barre syndrome. Moreover it is a great mimic of co-existing epidemics like Malaria, Chikungunya and Zika virus disease, which are also mosquito-borne diseases. The atypical manifestations noted in dengue can be mutisystemic and multifacetal. In clinical practice, the occurrence of atypical presentation should prompt us to investigate for dengue. Knowledge of expanded dengue helps to clinch the diagnosis of dengue early, especially during ongoing epidemics, avoiding further battery of investigations. Dengue has proved to be the epidemic with the ability to recur and has a diverse array of presentation as seen in large series from India, Srilanka, Indonesia and Taiwan. WHO has given the case definition of dengue fever in their comprehensive guidelines. Accordingly, a probable case is defined as acute febrile illness with two or more of any findings viz. headache, retro-orbital pain, myalgia, arthralgia, rash, hemorrhagic manifestations, leucopenia and supportive serology. There have been cases of patients admitted with fever, altered mentation with or without neck stiffness and pyramidal tract signs. Some had seizures or status epilepticus as presentation. When they were tested for serology, dengue was positive. After ruling out other causes, dengue remained the only culprit. We have come across varied presentations of dengue fever in clinical practice and the present article throws light on atypical manifestations of dengue. © Journal of the Association of Physicians of India 2011.

  9. [Autochthonous dengue].

    PubMed

    Sorge, F; Minodier, P; Velayudhan-Deschamps, N

    2016-12-01

    Dengue is the arboviral disease that has massively spread in intertropical regions these past few years. The rise in imported cases of dengue and the rapid spread of the Aedes vector mosquitoes in continental France since 2004 explain the occurrence of indigenous dengue cases among the nonimmune population and points to an epidemic risk. Severe dengue cases are rare, but lethality is highest among children under 5 years of age. Like pediatricians in tropical regions, we must learn how dengue presents in metropolitan France and how it can be managed, and pay special attention to severe and potentially fatal forms. The epidemiological, pathophysiological, clinical, diagnostic, and therapeutic characteristics of dengue are presented herein. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  10. Dengue and Dengue Hemorrhagic Fever

    PubMed Central

    Gubler, Duane J.

    1998-01-01

    Dengue fever, a very old disease, has reemerged in the past 20 years with an expanded geographic distribution of both the viruses and the mosquito vectors, increased epidemic activity, the development of hyperendemicity (the cocirculation of multiple serotypes), and the emergence of dengue hemorrhagic fever in new geographic regions. In 1998 this mosquito-borne disease is the most important tropical infectious disease after malaria, with an estimated 100 million cases of dengue fever, 500,000 cases of dengue hemorrhagic fever, and 25,000 deaths annually. The reasons for this resurgence and emergence of dengue hemorrhagic fever in the waning years of the 20th century are complex and not fully understood, but demographic, societal, and public health infrastructure changes in the past 30 years have contributed greatly. This paper reviews the changing epidemiology of dengue and dengue hemorrhagic fever by geographic region, the natural history and transmission cycles, clinical diagnosis of both dengue fever and dengue hemorrhagic fever, serologic and virologic laboratory diagnoses, pathogenesis, surveillance, prevention, and control. A major challenge for public health officials in all tropical areas of the world is to devleop and implement sustainable prevention and control programs that will reverse the trend of emergent dengue hemorrhagic fever. PMID:9665979

  11. Dengue fever.

    PubMed

    Skinner, Anita

    Dengue fever is a notifiable infectious disease in England because of its geographic expansion and the increase in the number of epidemics. The article highlighted the importance of informing overseas travellers of the risk of acquiring dengue fever and advising them on personal protective measures.

  12. Dengue Fever Treatment

    MedlinePlus

    ... linkedin Dengue Fever Treatment Dengue Fever Dengue Fever Biology and Transmission Prevention Diagnosis Treatment Featured Research NIAID- ... last reviewed on February 8, 2011 Dengue Fever Biology and Transmission Prevention Diagnosis Treatment Featured Research ^ Return ...

  13. DENGUE VACCINES.

    PubMed

    Thisyakorn, Usa; Thisyakorn, Chule

    2015-01-01

    The uniqueness of the dengue viruses (DENVs) and the spectrum of disease resulting from infection have made dengue vaccine development difficult. Several vaccine candidates are currently being evaluated in clinical studies. The candidate currently at the most advanced clinical development stage, a live-attenuated tetravalent vaccine based on the chimeric yellow fever-dengue virus (CYD-TDV), has progressed to Phase 3 efficacy studies. Several other live-attenuated vaccines, as well as subunit, DNA, and purified inactivated vaccine candidates are at earlier stages of clinical development. Additional technological approaches, such as virus-vectored and Virus-Like Particles (VLP)-based vaccines are under evaluation in preclinical studies.

  14. Dengue Epidemiology

    MedlinePlus

    ... Address What's this? Submit What's this? Submit Button ... fever (DF) is caused by any of four closely related viruses, or serotypes: dengue 1-4. Infection with one serotype does not protect against the ...

  15. Dengue vaccines: implications for dengue control.

    PubMed

    Robinson, Matthew L; Durbin, Anna P

    2017-10-01

    Dengue, the most common arbovirus, is an increasingly significant cause of morbidity worldwide. After decades of research, an approved tetravalent dengue vaccine is finally available. Models constructed using recently available vaccine efficacy data allow for a data-driven discussion of the potential impact of dengue vaccine deployment on global control. Phase 3 efficacy trials demonstrated that the approved dengue vaccine, chimeric yellow fever-dengue-tetravalent dengue vaccine, has an efficacy of 60% against dengue illness of any severity. However, among dengue unexposed recipients, vaccination offers limited efficacy and may increase dengue severity. The WHO consequently recommends dengue vaccination for populations in which 70% of intended recipients are dengue seropositive. Models predict that routine childhood dengue vaccine may reduce dengue burden, but over time, population-level impact may be limited. Additional vaccine candidates in late-stage development may not suffer from the same limitations as chimeric yellow fever-dengue-tetravalent dengue vaccine. The efficacy and safety profile of the recently approved dengue vaccine is favorable only in previously dengue exposed recipients, which limits its potential for global control. Future work must evaluate the approved vaccine's long-term durability, efficacy of other late phase vaccine candidates, and potential for vector control efforts to work synergistically with vaccine deployment.

  16. Percepcion de los profesores universitarios acerca del concepto cultura cientifica y de sus implicaciones en el nuevo bachillerato del Recinto de Rio Piedras de la Universidad de Puerto Rico

    NASA Astrophysics Data System (ADS)

    Ramos Pastrana, Nilsa

    El Senado Academico del Recinto de Rio Piedras de la Universidad de Puerto Rico aprobo en el ano academico 2005-2006 la Certificacion 46, que contiene los lineamientos de un nuevo bachillerato. Este nuevo bachillerato introdujo cambios significativos en el curriculo tradicional. Entre ellos se encuentra la reduccion del componente de educacion general y el de Ciencias Biologicas en particular. La reduccion de creditos en el componente de Ciencias Biologicas ha obligado a reevaluar el concepto de cultura cientifica que desarrollan esos cursos. El proposito del estudio consistio en auscultar las percepciones de los profesores de las Facultades de Administracion de Empresas, Humanidades, Ciencias Sociales, Ciencias Naturales, Educacion y Estudios Generales del Recinto de Rio Piedras de la Universidad de Puerto Rico en torno al concepto de cultura cientifica, los contenidos disciplinares del curso de Ciencias Biologicas y la reduccion de creditos en el nuevo bachillerato. Las preguntas que guiaron la investigacion fueron: ¿cuales son las percepciones que tienen los profesores de las Facultades de Administracion de Empresas, Ciencias Sociales, Estudios Generales, Ciencias Naturales, Humanidades y Educacion, en torno al concepto de cultura cientifica y los contenidos disciplinares del curso de Ciencias Biologicas? ¿cuales son las percepciones que tienen los profesores de Ciencias Biologicas en torno al concepto cultura cientifica y los contenidos disciplinares del curso de Ciencias Biologicas? ¿existen diferencias significativas por facultad, genero, experiencia, rango y nombramiento en las percepciones que tienen los profesores del Recinto de Rio Piedras de la Universidad de Puerto Rico sobre los elementos que caracterizan la cultura cientifica y los contenidos biologicos que deben tener los egresados del Recinto? ¿que implicaciones curriculares tienen estos testimonios en el desarrollo del concepto de cultura cientifica en el nuevo bachillerato? Para realizar la

  17. Effect of dengue-1 antibodies on American dengue-2 viral infection and dengue haemorrhagic fever.

    PubMed

    Kochel, Tadeusz J; Watts, Douglas M; Halstead, Scott B; Hayes, Curtis G; Espinoza, Angelica; Felices, Vidal; Caceda, Roxana; Bautista, Christian T; Montoya, Ysabel; Douglas, Susan; Russell, Kevin L

    2002-07-27

    In Iquitos, Peru, no cases of dengue haemorrhagic fever have been recorded in individuals infected with dengue-1 virus followed by American genotype dengue-2 (American dengue-2) virus. We assayed serum samples collected in Iquitos that tested positive for antibodies of monotype dengue-1 and monotype dengue-2 using a plaque reduction neutralisation test to determine their ability to neutralise the infectivity of two dengue-1 viruses, two American dengue-2 viruses, and two Asian dengue-2 viruses. Sera positive for the dengue-1 antibody neutralised dengue-1 viruses and American dengue-2 viruses much more effectively than Asian dengue-2 viruses. Neutralisation of American dengue-2 virus by sera positive for dengue-1 antibodies may account for the absence of dengue haemorrhagic fever in individuals infected with dengue-1 in 1990-91 followed by American dengue-2 virus in 1995 in Iquitos, Peru.

  18. Hypokalemic quadriparesis in dengue.

    PubMed

    Mishra, Vikas; Harbada, Rishit; Sharma, Akhilesh; Mishra, Meenakshi

    2015-01-01

    Dengue infection is the leading cause of illness and death in tropical and subtropical regions of the world. The common complications associated with dengue fever are usual hematological abnormalities, shock, and organ failure. The neurological complications of dengue are uncommon. However, evidence of dengue virus neurotropism and complications has been slowly but surely rising as seen from increased literature on this subject over the last decade. We report an uncommon case of hypokalemic quadriparesis with dengue that had a favorable outcome.

  19. Dengue viral infections

    PubMed Central

    Malavige, G; Fernando, S; Fernando, D; Seneviratne, S

    2004-01-01

    Dengue viral infections are one of the most important mosquito borne diseases in the world. They may be asymptomatic or may give rise to undifferentiated fever, dengue fever, dengue haemorrhagic fever (DHF), or dengue shock syndrome. Annually, 100 million cases of dengue fever and half a million cases of DHF occur worldwide. Ninety percent of DHF subjects are children less than 15 years of age. At present, dengue is endemic in 112 countries in the world. No vaccine is available for preventing this disease. Early recognition and prompt initiation of appropriate treatment are vital if disease related morbidity and mortality are to be limited. This review outlines aspects of the epidemiology of dengue infections, the dengue virus and its mosquito vector, clinical features and pathogenesis of dengue infections, and the management and control of these infections. PMID:15466994

  20. The dengue viruses.

    PubMed Central

    Henchal, E A; Putnak, J R

    1990-01-01

    Dengue, a major public health problem throughout subtropical and tropical regions, is an acute infectious disease characterized by biphasic fever, headache, pain in various parts of the body, prostration, rash, lymphadenopathy, and leukopenia. In more severe or complicated dengue, patients present with a severe febrile illness characterized by abnormalities of hemostasis and increased vascular permeability, which in some instances results in a hypovolemic shock. Four distinct serotypes of the dengue virus (dengue-1, dengue-2, dengue-3, and dengue-4) exist, with numerous virus strains found worldwide. Molecular cloning methods have led to a greater understanding of the structure of the RNA genome and definition of virus-specific structural and nonstructural proteins. Progress towards producing safe, effective dengue virus vaccines, a goal for over 45 years, has been made. Images PMID:2224837

  1. Dengue fever (image)

    MedlinePlus

    Dengue fever, or West Nile fever, is a mild viral illness transmitted by mosquitoes which causes fever, ... second exposure to the virus can result in Dengue hemorrhagic fever, a life-threatening illness.

  2. Dengue reemergence in Argentina.

    PubMed Central

    Avilés, G.; Rangeón, G.; Vorndam, V.; Briones, A.; Baroni, P.; Enria, D.; Sabattini, M. S.

    1999-01-01

    Aedes aegypti, eradicated from Argentina in 1963, has now reinfested the country as far south as Buenos Aires. In 1997, four persons with travel histories to Brazil, Ecuador, or Venezuela had confirmed dengue, and surveillance for indigenous transmission allowed the detection of 19 dengue cases in Salta Province. These cases of dengue are the first in Argentina since 1916 and represent a new southern extension of dengue virus. PMID:10460181

  3. Dengue reemergence in Argentina.

    PubMed

    Avilés, G; Rangeón, G; Vorndam, V; Briones, A; Baroni, P; Enria, D; Sabattini, M S

    1999-01-01

    Aedes aegypti, eradicated from Argentina in 1963, has now reinfested the country as far south as Buenos Aires. In 1997, four persons with travel histories to Brazil, Ecuador, or Venezuela had confirmed dengue, and surveillance for indigenous transmission allowed the detection of 19 dengue cases in Salta Province. These cases of dengue are the first in Argentina since 1916 and represent a new southern extension of dengue virus.

  4. Dengue in children.

    PubMed

    Verhagen, Lilly M; de Groot, Ronald

    2014-11-01

    Dengue is a mosquito-borne viral disease of expanding geographical range and increasing incidence. The vast majority of dengue cases are children less than 15 years of age. Dengue causes a spectrum of illness from mild fever to severe disease with plasma leakage and shock. Infants and children with secondary heterologous dengue infections are most at risk for severe dengue disease. Laboratory diagnosis of dengue can be established within five days of disease onset by direct detection of viral components in serum. After day five, serologic diagnosis provides indirect evidence of dengue. Currently, no effective antiviral agents are available to treat dengue infection. Therefore, treatment remains supportive, with emphasis on close hematological monitoring, recognition of warning signs of severe disease and fluid-replacement therapy and/or blood transfusions when required. Development of a dengue vaccine is considered a high public health priority. A safe and efficacious dengue vaccine would also be important for travelers. This review highlights the current understanding of dengue in children, including its clinical manifestations, pathogenesis, diagnostic tests, management and prevention. Copyright © 2014 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

  5. Dengue infections in travellers

    PubMed Central

    Wilder-Smith, Annelies

    2012-01-01

    Dengue has been designated a major international public health problem by the World Health Organization (WHO). It is endemic in most tropical and sub-tropical countries, which are also popular tourist destinations. Travellers are not only at significant risk of acquiring dengue but they also contribute to its spread to non-endemic regions. Furthermore, they may serve as sentinels to alert the international community to epidemics in dengue-endemic regions. GeoSentinel, a global surveillance network, monitors all travel-related illnesses and estimates that dengue accounts for 2% of all illness in travellers returning from dengue-endemic regions. In fact, in travellers returning from South-east Asia, dengue is now a more frequent cause of febrile illness than malaria. Dengue-infected travellers returning home to countries where the vector exists can place the local population at risk of further spread of the disease with subsequent autochthonous cycles of infection. The true incidence of dengue amongst travellers may be underestimated because of variability in reporting requirements in different countries and under-diagnosis owing to the non-specific clinical presentation of the disease. Risk factors for acquiring dengue include duration of stay, season of travel and epidemic activity at the destination. Any pre-travel advice on the risks of developing dengue infections should consider these factors. PMID:22668447

  6. Dengue in India

    PubMed Central

    Gupta, Nivedita; Srivastava, Sakshi; Jain, Amita; Chaturvedi, Umesh C.

    2012-01-01

    Dengue virus belongs to family Flaviviridae, having four serotypes that spread by the bite of infected Aedes mosquitoes. It causes a wide spectrum of illness from mild asymptomatic illness to severe fatal dengue haemorrhagic fever/dengue shock syndrome (DHF/DSS). Approximately 2.5 billion people live in dengue-risk regions with about 100 million new cases each year worldwide. The cumulative dengue diseases burden has attained an unprecedented proportion in recent times with sharp increase in the size of human population at risk. Dengue disease presents highly complex pathophysiological, economic and ecologic problems. In India, the first epidemic of clinical dengue-like illness was recorded in Madras (now Chennai) in 1780 and the first virologically proved epidemic of dengue fever (DF) occurred in Calcutta (now Kolkata) and Eastern Coast of India in 1963-1964. During the last 50 years a large number of physicians have treated and described dengue disease in India, but the scientific studies addressing various problems of dengue disease have been carried out at limited number of centres. Achievements of Indian scientists are considerable; however, a lot remain to be achieved for creating an impact. This paper briefly reviews the extent of work done by various groups of scientists in this country. PMID:23041731

  7. Dengue-associated kidney disease.

    PubMed

    Lizarraga, Karlo J; Nayer, Ali

    2014-01-01

    A mosquito-borne viral illness highly prevalent in the tropics and subtropics, dengue is considered a major global health threat by the World Health Organization. Directory of Open Access Journals (DOAJ), Google Scholar, PubMed (NLM), LISTA (EBSCO) and Web of Science have been searched. An RNA virus from the genus Flavivirus, dengue virus is transmitted by Aedes aegypti,the yellow fever mosquito. Dengue is asymptomatic in as many as one half of infected individuals. Dengue fever is an acute febrile illness accompanied by constitutional symptoms. Dengue hemorrhagic fever and dengue shock syndrome are the severe forms of dengue infection.Dengue infection has been associated with a variety of renal disorders. Acute renal failure is a potential complication of severe dengue infection and is typically associated with hypotension, rhabdomyolysis, or hemolysis. Acute renal failure complicates severe dengue infection in 2-5% of the cases and carries a high mortality rate. Proteinuria has been detected in as high as 74% of patients with severe dengue infection. Hematuria has been reported in up to 12.5% of patients. Various types of glomerulonephritis have been reported during or shortly after dengue infection in humans and mouse models of dengue infection. Mesangial proliferation and immune complex deposition are the dominant histologic features of dengue-associated glomerulonephritis. On a rare occasion, dengue infection is associated with systemic autoimmune disorders involving the kidneys. In the vast majority of cases, dengue infection and associated renal disorders are self-limited.

  8. Dengue virus vaccine development.

    PubMed

    Yauch, Lauren E; Shresta, Sujan

    2014-01-01

    Dengue virus (DENV) is a significant cause of morbidity and mortality in tropical and subtropical regions, causing hundreds of millions of infections each year. Infections range from asymptomatic to a self-limited febrile illness, dengue fever (DF), to the life-threatening dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS). The expanding of the habitat of DENV-transmitting mosquitoes has resulted in dramatic increases in the number of cases over the past 50 years, and recent outbreaks have occurred in the United States. Developing a dengue vaccine is a global health priority. DENV vaccine development is challenging due to the existence of four serotypes of the virus (DENV1-4), which a vaccine must protect against. Additionally, the adaptive immune response to DENV may be both protective and pathogenic upon subsequent infection, and the precise features of protective versus pathogenic immune responses to DENV are unknown, complicating vaccine development. Numerous vaccine candidates, including live attenuated, inactivated, recombinant subunit, DNA, and viral vectored vaccines, are in various stages of clinical development, from preclinical to phase 3. This review will discuss the adaptive immune response to DENV, dengue vaccine challenges, animal models used to test dengue vaccine candidates, and historical and current dengue vaccine approaches.

  9. Mosquitoes, models, and dengue.

    PubMed

    Lifson, A R

    1996-05-04

    In the last 10 years dengue has spread markedly through Latin America and the Caribbean (Dominican Republic, Jamaica, Barbados, Mexico, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, Panama, Ecuador, Colombia, Venezuela, and Brazil). The mosquito Aedes aegypti has taken advantage of increased urbanization and crowding to transmit the dengue virus. The mosquito infests tires, cans, and water jars near dwellings. The female mosquito practices multiple, interrupted feeding. Thus, mosquito infesting and feeding practices facilitate dengue transmission in crowded conditions. Factors contributing to the spread of dengue include numbers of infected and susceptible human hosts, strain of dengue virus, size of mosquito population, feeding habits, time from infection to ability to transmit virus for both vector and host, likelihood of virus transmission from human to mosquito to human, and temperature (which affects vector distribution, size, feeding habits, and extrinsic incubation period). Public health models may use simulation models to help them plan or evaluate the potential impact of different intervention strategies and/or of environmental changes (e.g., global warming). Other factors contributing to the dengue epidemic are international travel, urbanization, population growth, crowding, poverty, a weakened public health infrastructure, and limited support for sustained disease control programs. Molecular epidemiology by nucleic acid sequence analysis is another sophisticated technique used to study infectious diseases. It showed that dengue type 3 isolated from Panama and Nicaragua in 1994 was identical to that responsible for the major dengue hemorrhagic fever epidemics in Sri Lanka and India in the 1980s. Public health officials must remember three priorities relevant to dengue and other emerging infections: the need to strengthen surveillance efforts, dedicated and sustained involvement in prevention and control needs at the local level, and a strong

  10. Dengue: a continuing global threat

    PubMed Central

    Guzman, Maria G.; Halstead, Scott B.; Artsob, Harvey; Buchy, Philippe; Farrar, Jeremy; Gubler, Duane J.; Hunsperger, Elizabeth; Kroeger, Axel; Margolis, Harold S.; Martínez, Eric; Nathan, Michael B.; Pelegrino, Jose Luis; Simmons, Cameron; Yoksan, Sutee; Peeling, Rosanna W.

    2014-01-01

    Dengue fever and dengue haemorrhagic fever are important arthropod-borne viral diseases. Each year, there are ~50 million dengue infections and ~500,000 individuals are hospitalized with dengue haemorrhagic fever, mainly in Southeast Asia, the Pacific and the Americas. Illness is produced by any of the four dengue virus serotypes. A global strategy aimed at increasing the capacity for surveillance and outbreak response, changing behaviours and reducing the disease burden using integrated vector management in conjunction with early and accurate diagnosis has been advocated. Antiviral drugs and vaccines that are currently under development could also make an important contribution to dengue control in the future. PMID:21079655

  11. Rhombencephalitis associated with Dengue fever.

    PubMed

    Verma, Rajesh; Bharti, Kavita; Mehta, Mannan; Bansod, Amrit

    2016-05-01

    Dengue infection is gradually disseminating throughout the world in alarming proportions. It is a arbovirus infection,transmitted by aedes mosquitoes. It is a multi-systemic disorder associated with varied neurological complications. There is increased trend of development of neurological complications in dengue fever. The neurological complications arising due to dengue infection can be categorized into central and neuromuscular complications. The central nervous system disorders reported with dengue fever are encephalopathy,encephalitis and myelitis.Here we report a case of rhombencephalitis associated with dengue fever. The literature does not mention rhombencephalitis occurring with dengue illness. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Dengue shock syndrome

    PubMed Central

    Sudulagunta, Sreenivasa Rao; Sodalagunta, Mahesh Babu; Sepehrar, Mona; Bangalore Raja, Shiva Kumar; Nataraju, Aravinda Settikere; Kumbhat, Mounica; Sathyanarayana, Deepak; Gummadi, Siddharth; Burra, Hemanth Kumar

    2016-01-01

    Dengue fever is a mosquito-borne arthropod-borne viral (arboviral) tropical disease in humans affecting 50–528 million people worldwide. The acute abdominal complications of dengue fever are acute appendicitis, acute pancreatitis, acute acalculous cholecystitis and non-specific peritonitis. Acute pancreatitis with new onset diabetes in dengue shock syndrome (DSS) is very rarely reported. We describe a case of 30-year-old man admitted in intensive care unit and was diagnosed with DSS with RT-PCR, NS1 antigen and dengue IgM antibody being positive. Abdominal ultrasound and computerized tomography confirmed acute pancreatitis. Patient required insulin after recovery. Diabetes mellitus caused by DSS is under-reported and lack of awareness may increase mortality and morbidity. PMID:28031845

  13. Controversies in dengue pathogenesis

    PubMed Central

    Halstead, Scott B

    2012-01-01

    Research into the pathogenesis of dengue fever has exploded over the last half-century, with issues that were considered simple becoming more complex as additional data are found. This has led to the development of a number of controversies that are being studied across the globe and debated in the literature. In this paper, the following six controversies are analysed and, where possible, resolved: the 1997 World Health Organization (WHO) case definition of dengue haemorrhagic fever (DHF) is not useful; DHF is not significantly associated with secondary dengue infection; DHF results from infection with a ‘virulent’ dengue virus; DHF is owing to abnormal T-cell responses; DHF results from auto-immune responses; and DHF results from direct infection of endothelial cells. PMID:22668442

  14. Dengue hemorrhagic fever

    MedlinePlus

    ... a severe, potentially deadly infection spread by some mosquitos. Causes Four different dengue viruses are known to ... occurs when a person is bitten by a mosquito that is infected with the virus. The mosquito ...

  15. [Urbanization and dengue ecology].

    PubMed

    Tauil, P L

    2001-01-01

    Demographic changes occurring in underdeveloped countries due to intense rural-urban migration since the 1960s have resulted in overcrowded cities with multiple deficiencies, particularly in housing and basic sanitation. Some 20% of the population in large and medium-sized cities live in slums or under similar conditions. Lack of regular water supply and public garbage collection foster the proliferation of potential breeding sites for Aedes aegypti (the main mosquito vector for dengue), including precarious reservoirs for potable water and disposable recipients which accumulate water, like used cans and plastic and glass bottles. Modern industries also produce large volumes of disposable materials. Propagation of the dengue virus and the spread of dengue vectors are favored by the high intensity, frequency, and speed of private and public transportation. Such factors can help explain the re-emergence of dengue, the most important arbovirus in the world today, affecting thousands of people each year.

  16. Detection of dengue virus in platelets isolated from dengue patients.

    PubMed

    Noisakran, Sansanee; Gibbons, Robert V; Songprakhon, Pucharee; Jairungsri, Aroonroong; Ajariyakhajorn, Chuanpis; Nisalak, Ananda; Jarman, Richard G; Malasit, Prida; Chokephaibulkit, Kulkanya; Perng, Guey Chuen

    2009-03-01

    Though thrombocytopenia or dysfunction of platelets is common in dengue virus infection, the role of platelets has not been established. We enrolled 33 hospitalized children with serologically confirmed dengue virus infection. Blood specimens were collected during hospitalization. Platelets and plasma were isolated from the whole blood. Detection of dengue virus in plasma and platelets was carried out by RT-PCR with primers that can differentiate different dengue serotypes simultaneously, and by electron transmission microscopy (EM). Dengue viral RNA was detected in the platelets and plasma by conventional RT-PCR. A significantly higher percentage of dengue viral RNA was detected in platelets than in plasma (p = 0.03). Platelets isolated 5 days after onset of fever were most likely positive for viral RNA. Concurrent infection or co-circulation with multiple dengue serotypes was observed in 12% of patients. Infrequently, negative-stranded dengue viral RNA was detected in platelets and in plasma. Importantly, EM confirmed the presence of dengue viral-like particles inside platelets prepared from dengue patients. Our findings suggest the presence of dengue virus in platelets may be associated with the dysfunction of platelets observed in dengue patients.

  17. Climate variation drives dengue dynamics

    PubMed Central

    Xu, Lei; Stige, Leif C.; Chan, Kung-Sik; Zhou, Jie; Yang, Jun; Sang, Shaowei; Wang, Ming; Yang, Zhicong; Yan, Ziqiang; Jiang, Tong; Lu, Liang; Yue, Yujuan; Liu, Xiaobo; Lin, Hualiang; Xu, Jianguo; Liu, Qiyong; Stenseth, Nils Chr.

    2017-01-01

    Dengue, a viral infection transmitted between people by mosquitoes, is one of the most rapidly spreading diseases in the world. Here, we report the analyses covering 11 y (2005–2015) from the city of Guangzhou in southern China. Using the first 8 y of data to develop an ecologically based model for the dengue system, we reliably predict the following 3 y of dengue dynamics—years with exceptionally extensive dengue outbreaks. We demonstrate that climate conditions, through the effects of rainfall and temperature on mosquito abundance and dengue transmission rate, play key roles in explaining the temporal dynamics of dengue incidence in the human population. Our study thus contributes to a better understanding of dengue dynamics and provides a predictive tool for preventive dengue reduction strategies. PMID:27940911

  18. Dengue-associated kidney disease

    PubMed Central

    J Lizarraga, Karlo; Nayer, Ali

    2014-01-01

    Context: A mosquito-borne viral illness highly prevalent in the tropics and subtropics, dengue is considered a major global health threat by the World Health Organization. Evidence Acquisitions: Directory of Open Access Journals (DOAJ), Google Scholar, PubMed (NLM), LISTA (EBSCO) and Web of Science have been searched. Results: An RNA virus from the genus Flavivirus, dengue virus is transmitted by Aedes aegypti,the yellow fever mosquito. Dengue is asymptomatic in as many as one half of infected individuals. Dengue fever is an acute febrile illness accompanied by constitutional symptoms. Dengue hemorrhagic fever and dengue shock syndrome are the severe forms of dengue infection.Dengue infection has been associated with a variety of renal disorders. Acute renal failure is a potential complication of severe dengue infection and is typically associated with hypotension, rhabdomyolysis, or hemolysis. Acute renal failure complicates severe dengue infection in 2-5% of the cases and carries a high mortality rate. Proteinuria has been detected in as high as 74% of patients with severe dengue infection. Hematuria has been reported in up to 12.5% of patients. Various types of glomerulonephritis have been reported during or shortly after dengue infection in humans and mouse models of dengue infection. Mesangial proliferation and immune complex deposition are the dominant histologic features of dengue-associated glomerulonephritis. On a rare occasion, dengue infection is associated with systemic autoimmune disorders involving the kidneys. Conclusions: In the vast majority of cases, dengue infection and associated renal disorders are self-limited. PMID:24772398

  19. Observations on Hospitalized Dengue Patients

    DTIC Science & Technology

    1987-01-01

    DENGUE PATIENTS IN MANILA Carman. R. Min oto* be" S. Siqpo Ommon D. Leus** Curds G. Ibyes* INTRODUCION to the Hospital of Infant Jesus between October...31, 1983 and March 31, 1984: Criteria for the diagnosis of dengue Dengue hemorrhagic fever (DHF) has been recognized infection were based on the...titer of later sample < 1:640. DHF epidemic.4𔃿 Since that time, there have only been a few- was differentiated from dengue fever (DF), and DHF was

  20. Dengue 3 Epidemic, Havana, 2001

    PubMed Central

    Peláez, Otto; Kourí, Gustavo; Pérez, Raúl; San Martín, José L.; Vázquez, Susana; Rosario, Delfina; Mora, Regla; Quintana, Ibrahim; Bisset, Juan; Cancio, Reynel; Masa, Ana M; Castro, Osvaldo; González, Daniel; Avila, Luis C.; Rodríguez, Rosmari; Alvarez, Mayling; Pelegrino, Jose L.; Bernardo, Lídice; Prado, Irina

    2004-01-01

    In June 2001, dengue transmission was detected in Havana, Cuba; 12,889 cases were reported. Dengue 3, the etiologic agent of the epidemic, caused the dengue hemorrhagic fever only in adults, with 78 cases and 3 deaths. After intensive vector control efforts, no new cases have been detected. PMID:15200868

  1. [Nitric oxide in dengue pathology].

    PubMed

    Rodriguez-Ortega, M

    1998-01-01

    Nitric oxide (NO) is a multifunctional molecule that is involved in citotoxic as well as citoprotective processes, it's synthesis is highly regulated by the cell because an alteration in NO production is associated with a variety of pathologies, such as Septic, Anaphylactic and Hemorrhagic Shock. The clinical feature of dengue virus infection has a spectrum that goes from mild, dengue fever, to a severe disease, dengue hemorrhagic fever/dengue shock. Here, some evidences are discussed that links NO with the pathology of the severe disease cause by dengue virus.

  2. Dengue virus-mosquito interactions.

    PubMed

    Halstead, Scott B

    2008-01-01

    The mosquito Aedes aegypti is more widely dispersed now than at any time in the past, placing billions of humans at risk of infection with one or more of the four dengue viruses. This review presents and discusses information on mosquito-dengue infection dynamics and describes the prominent role that temperature and rainfall play in controlling dengue viral transmission including discussions of the effect of interannual climate variations and the predicted effect of global warming. Complementary human determinants of dengue epidemiology include viremia titer, variation in viremic period, enhanced viremias, and threshold viremia. Topics covered include epidemiological phenomena such as traveling waves, the generation of genetic diversity of dengue viruses following virgin soil introductions and in hyperendemic settings, and evidence for and against viral virulence as a determinant of the severity of dengue infections. Also described is the crucial role of monotypic and heterotypic herd immunity in shaping dengue epidemic behavior.

  3. Dengue Virus Infection in Africa

    PubMed Central

    Kuritsky, Joel N.; Letson, G. William; Margolis, Harold S.

    2011-01-01

    Reported incidence of dengue has increased worldwide in recent decades, but little is known about its incidence in Africa. During 1960–2010, a total of 22 countries in Africa reported sporadic cases or outbreaks of dengue; 12 other countries in Africa reported dengue only in travelers. The presence of disease and high prevalence of antibody to dengue virus in limited serologic surveys suggest endemic dengue virus infection in all or many parts of Africa. Dengue is likely underrecognized and underreported in Africa because of low awareness by health care providers, other prevalent febrile illnesses, and lack of diagnostic testing and systematic surveillance. Other hypotheses to explain low reported numbers of cases include cross-protection from other endemic flavivirus infections, genetic host factors protecting against infection or disease, and low vector competence and transmission efficiency. Population-based studies of febrile illness are needed to determine the epidemiology and true incidence of dengue in Africa. PMID:21801609

  4. Progress towards a dengue vaccine.

    PubMed

    Webster, Daniel P; Farrar, Jeremy; Rowland-Jones, Sarah

    2009-11-01

    The spread of dengue virus throughout the tropics represents a major, rapidly growing public health problem with an estimated 2.5 billion people at risk of dengue fever and the life-threatening disease, severe dengue. A safe and effective vaccine for dengue is urgently needed. The pathogenesis of severe dengue results from a complex interaction between the virus, the host, and, at least in part, immune-mediated mechanisms. Vaccine development has been slowed by fears that immunisation might predispose individuals to the severe form of dengue infection. A pipeline of candidate vaccines now exists, including live attenuated, inactivated, chimeric, DNA, and viral-vector vaccines, some of which are at the stage of clinical testing. In this Review, we present what is understood about dengue pathogenesis and its implications for vaccine design, the progress that is being made in the development of a vaccine, and the future challenges.

  5. Quasispecies of dengue virus.

    PubMed

    Kurosu, Takeshi

    2011-12-01

    Pathogenic viruses have RNA genomes that cause acute and chronic infections. These viruses replicate with high mutation rates and exhibit significant genetic diversity, so-called viral quasispecies. Viral quasispecies play an important role in chronic infectious diseases, but little is known about their involvement in acute infectious diseases such as dengue virus (DENV) infection. DENV, the most important human arbovirus, is a causative agent of dengue fever (DF) and dengue hemorrhagic fever (DHF). Accumulating observations suggest that DENV exists as an extremely diverse virus population, but its biological significance is unclear. In other virus diseases, quasispecies affect the therapeutic strategies using drugs and vaccines. Here, I describe the quasispecies of DENV and discuss the possible role of quasispecies in the pathogenesis of and therapeutic strategy against DENV infection in comparison with other viruses such as Hepatitis C virus, human immunodeficiency virus type 1, and poliovirus.

  6. Micronutrients and dengue.

    PubMed

    Ahmed, Sundus; Finkelstein, Julia L; Stewart, Anna M; Kenneth, John; Polhemus, Mark E; Endy, Timothy P; Cardenas, Washington; Mehta, Saurabh

    2014-11-01

    Dengue virus infection is the most widespread mosquito-borne viral infection in humans and has emerged as a serious global health challenge. In the absence of effective treatment and vaccine, host factors including nutritional status, which may alter disease progression, need investigation. The interplay between nutrition and other infections is well-established, and modulation of nutritional status often presents a simple low-cost method of interrupting transmission, reducing susceptibility, and/or ameliorating disease severity. This review examines the evidence on the role of micronutrients in dengue virus infection. We found critical issues and often inconsistent results across studies; this finding along with the lack of sufficient literature in this field have limited our ability to make any recommendations. However, vitamins D and E have shown promise in small supplementation trials. In summary, the role of micronutrients in dengue virus infection is an exciting research area and needs to be examined in well-designed studies with larger samples.

  7. Protect Yourself and Your Baby from Dengue

    MedlinePlus

    Protect Yourself and Your Baby from Dengue Avoid mosquito bites during pregnancy to prevent dengue in your ... To prevent dengue virus infection during pregnancy » Use mosquito repellents with up to 50% DEET, picaridin, IR3535 ...

  8. A Dengue Vaccine.

    PubMed

    Durbin, Anna P

    2016-06-30

    Denvaxia is the first licensed vaccine for the prevention of dengue. It is a live vaccine developed using recombinant DNA technology. The vaccine is given as three doses over the course of a year and has the potential to prevent hundreds of thousands of hospitalizations each year.

  9. Dengue in Florida (USA)

    PubMed Central

    Rey, Jorge R.

    2014-01-01

    Florida (USA), particularly the southern portion of the State, is in a precarious situation concerning arboviral diseases. The geographic location, climate, lifestyle, and the volume of travel and commerce are all conducive to arbovirus transmission. During the last decades, imported dengue cases have been regularly recorded in Florida, and the recent re-emergence of dengue as a major public health concern in the Americas has been accompanied by a steady increase in the number of imported cases. In 2009, there were 28 cases of locally transmitted dengue in Key West, and in 2010, 65 cases were reported. Local transmission was also reported in Martin County in 2013 (29 cases), and isolated locally transmitted cases were also reported from other counties in the last five years. Dengue control and prevention in the future will require close cooperation between mosquito control and public health agencies, citizens, community and government agencies, and medical professionals to reduce populations of the vectors and to condition citizens and visitors to take personal protection measures that minimize bites by infected mosquitoes. PMID:26462955

  10. [Dengue, Zika and Chikungunya].

    PubMed

    Kantor, Isabel N

    2016-01-01

    Arboviruses are transmitted by arthropods, including those responsible for the current pandemic: alphavirus (Chikungunya) and flaviviruses (dengue and Zika). Its importance increased in the Americas over the past 20 years. The main vectors are Aedes aegypti and A. albopictus. Dengue infection provides long lasting immunity against the specific serotype and temporary to the other three. Subsequent infection by another serotype determines more serious disease. There is a registered vaccine for dengue, Dengvaxia (Sanofi Pasteur). Other two (Butantan and Takeda) are in Phase III in 2016. Zika infection is usually asymptomatic or occurs with rash, conjunctivitis and not very high fever. There is no vaccine or specific treatment. It can be transmitted by parental, sexual and via blood transfusion. It has been associated with microcephaly. Chikungunya causes prolonged joint pain and persistent immune response. Two candidate vaccines are in Phase II. Dengue direct diagnosis is performed by virus isolation, RT-PCR and ELISA for NS1 antigen detection; indirect methods are ELISA-IgM (cross-reacting with other flavivirus), MAC-ELISA, and plaque neutralization. Zika is diagnosed by RT-PCR and virus isolation. Serological diagnosis cross-reacts with other flavivirus. For CHIKV culture, RT-PCR, MAC-ELISA and plaque neutralization are used. Against Aedes organophosphate larvicides (temephos), organophosphorus insecticides (malathion and fenitrothion) and pyrethroids (permethrin and deltamethrin) are usually employed. Resistance has been described to all these products. Vegetable derivatives are less expensive and biodegradable, including citronella oil, which microencapsulated can be preserved from evaporation.

  11. Human Immune Response to Dengue Infections

    DTIC Science & Technology

    1990-07-31

    soluble CD4 (sCD4), soluble CD8 (sCD8) interleukin-2 (IL-2) and interferon gamma (IFNy), in the sera of patients with DHF/DSS and dengue Fever (DF...soluble IL-2 receptor (sIL-2R) in the acute sera of patients with dengue hemorrhagic fever (DHF)/dengue shock syndrome (DSS) and with dengue fever (DF...21 4 I. INTRODUCTION Dengue virus infection induces two types of symptoms; dengue fever (DF) and dengue hemorrhagic fever (DHF)/dengue

  12. Outlook for a dengue vaccine.

    PubMed

    Norrby, R

    2014-05-01

    Dengue is an increasing medical problem in subtropical and tropical countries. The search for a safe and effective vaccine is complicated by the fact that there are four types of dengue virus and that, if a vaccine is live attenuated, it should be proven not to cause the life-threatening form of dengue, dengue haemorrhagic fever. So far one vaccine candidate, a four-valent chimeric vaccine constructed from a yellow fever vaccine strain, has reached large clinical trials and has been shown to offer protection against dengue types 1, 3 and 54 but not against dengue type 2. It is highly likely that an effective vaccine will be available in the next decade.

  13. Clustering, climate and dengue transmission.

    PubMed

    Junxiong, Pang; Yee-Sin, Leo

    2015-06-01

    Dengue is currently the most rapidly spreading vector-borne disease, with an increasing burden over recent decades. Currently, neither a licensed vaccine nor an effective anti-viral therapy is available, and treatment largely remains supportive. Current vector control strategies to prevent and reduce dengue transmission are neither efficient nor sustainable as long-term interventions. Increased globalization and climate change have been reported to influence dengue transmission. In this article, we reviewed the non-climatic and climatic risk factors which facilitate dengue transmission. Sustainable and effective interventions to reduce the increasing threat from dengue would require the integration of these risk factors into current and future prevention strategies, including dengue vaccination, as well as the continuous support and commitment from the political and environmental stakeholders.

  14. Dengue in a changing climate.

    PubMed

    Ebi, Kristie L; Nealon, Joshua

    2016-11-01

    Dengue is the world's most important arboviral disease in terms of number of people affected. Over the past 50 years, incidence increased 30-fold: there were approximately 390 million infections in 2010. Globalization, trade, travel, demographic trends, and warming temperatures are associated with the recent spread of the primary vectors Aedes aegypti and Aedes albopictus and of dengue. Overall, models project that new geographic areas along the fringe of current geographic ranges for Aedes will become environmentally suitable for the mosquito's lifecycle, and for dengue transmission. Many endemic countries where dengue is likely to spread further have underdeveloped health systems, increasing the substantial challenges of disease prevention and control. Control focuses on management of Aedes, although these efforts have typically had limited effectiveness in preventing outbreaks. New prevention and control efforts are needed to counter the potential consequences of climate change on the geographic range and incidence of dengue, including novel methods of vector control and dengue vaccines.

  15. Trends of Dengue Disease Epidemiology

    PubMed Central

    Cucunawangsih; Lugito, Nata Pratama Hardjo

    2017-01-01

    Dengue disease is an emerging mosquito-borne viral infection transmitted between humans by Aedes spp. that are distributed mainly in the tropical and subtropical region along with chikungunya and zika diseases. The distribution of dengue disease is influenced by local variation, such as geography, rainfall, temperature, and rapid urbanization or migration. The epidemy of mosquito-borne infection significantly led to increased number of cases and hyperendemicity which induce a more severe form of dengue accompanied by cocirculation of chikungunya and zika. The rapid global spreading of dengue disease created public health burdens that are presently unfulfilled by the absence of specific therapy, simple diagnosis tool for the early phase, and effective and efficient vector control system. This review highlights the current situation of dengue distribution, epidemiology, and new strategies for early dengue diagnosis and risk prediction of severity that can be used to improve oversight and alleviate the heavy burden of the disease. PMID:28579763

  16. Dengue Research Opportunities in the Americas

    PubMed Central

    Laughlin, Catherine A.; Morens, David M.; Cassetti, M. Cristina; Costero-Saint Denis, Adriana; San Martin, Jose-Luis; Whitehead, Stephen S.; Fauci, Anthony S.

    2012-01-01

    Dengue is a systemic arthropod-borne viral disease of major global public health importance. At least 2.5 billion people who live in areas of the world where dengue occurs are at risk of developing dengue fever (DF) and its severe complications, dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Repeated reemergences of dengue in sudden explosive epidemics often cause public alarm and seriously stress healthcare systems. The control of dengue is further challenged by the lack of effective therapies, vaccines, and point-of-care diagnostics. Despite years of study, even its pathogenic mechanisms are poorly understood. This article discusses recent advances in dengue research and identifies challenging gaps in research on dengue clinical evaluation, diagnostics, epidemiology, immunology, therapeutics, vaccinology/clinical trials research, vector biology, and vector ecology. Although dengue is a major global tropical pathogen, epidemiologic and disease control considerations in this article emphasize dengue in the Americas. PMID:22782946

  17. Virulence Markers of Dengue Viruses

    DTIC Science & Technology

    1988-06-10

    AD VIRULENCE MARKERS OF DENGUE VIRUSES 00 ANNUAL REPORT 0 James L. Hardy and Srisakul C. Kliks June 10, 1988 Supported by U.S. ARMY MEDICAL RESEARCH...Virulence Markers of Dengue Viruses (U) 12. PERSONAL AUTHOR(S) James L. Hardy ind Sriqakul.C. Klik,,q 13a. TYPE OF REPORT 13b. TIME COVERED 14. DATE OF...TERMS (Continue on reverse it necessary and identify by block number) FIELD GROUP SUB-GROUP Dengue viruses, dengue hemorrhagic fever, virulence, U3

  18. Overview of current situation of dengue and dengue vector control

    USDA-ARS?s Scientific Manuscript database

    Dengue is the most important arbovirus of humans in the world. It is caused by one of four closely related virus serotypes whose primary vector is Aedes aegypti and secondarily by Ae. albopictus. A global dengue pandemic began in Southeast Asia after World War II and has intensified during the las...

  19. Dengue eye disease.

    PubMed

    Ng, Aaron W; Teoh, Stephen C

    2015-01-01

    Dengue fever, a viral disease epidemic in some parts of the world, is of considerable international concern, with a growing incidence owing to developing urbanization, tourism, and trade. Ocular manifestations of dengue fever are uncommon, but of great significance. Proposed mechanisms include direct viral infection as well as immunologic phenomena. Common manifestations include subconjunctival, vitreous, and retinal hemorrhages; posterior uveitis; optic neuritis; and maculopathies such as foveolitis, hemorrhage, and edema. Main symptoms include blurring of vision, scotomata, metamorphopsia, and floaters. Diagnostic and monitoring investigations described included optical coherence tomography, fundus fluorescein and indocyanine green angiography, visual field analysis, and electrophysiologic tests. Management is based on clinical presentation and includes active surveillance as well as various anti-inflammatory and immunosuppressive therapies. There have been no prospective, randomized therapeutic trials, and it is unclear if the disease is self-limiting or if treatment is actually beneficial. Prognosis varies, ranging from full resolution to permanent vision loss despite intervention.

  20. Wolbachia versus dengue

    PubMed Central

    Bull, James J.; Turelli, Michael

    2013-01-01

    A novel form of biological control is being applied to the dengue virus. The agent is the maternally transmitted bacterium Wolbachia, naturally absent from the main dengue vector, the mosquito Aedes aegypti. Three Wolbachia-based control strategies have been proposed. One is suppression of mosquito populations by large-scale releases of males incompatible with native females; this intervention requires ongoing releases. The other interventions transform wild mosquito populations with Wolbachia that spread via the frequency-dependent fitness advantage of Wolbachia-infected females; those interventions potentially require just a single, local release for area-wide disease control. One of these latter strategies uses Wolbachia that shortens mosquito life, indirectly preventing viral maturation/transmission. The other strategy uses Wolbachia that block viral transmission. All interventions can be undermined by viral, bacterial or mosquito evolution; viral virulence in humans may also evolve. We examine existing theory, experiments and comparative evidence to motivate predictions about evolutionary outcomes. (i) The life-shortening strategy seems the most likely to be thwarted by evolution. (ii) Mosquito suppression has a reasonable chance of working locally, at least in the short term, but long-term success over large areas is challenging. (iii) Dengue blocking faces strong selection for viral resistance but may well persist indefinitely at some level. Virulence evolution is not mathematically predictable, but comparative data provide no precedent for Wolbachia increasing dengue virulence. On balance, our analysis suggests that the considerable possible benefits of these technologies outweigh the known negatives, but the actual risk is largely unknown. PMID:24481199

  1. Micronutrients and Dengue

    PubMed Central

    Ahmed, Sundus; Finkelstein, Julia L.; Stewart, Anna M.; Kenneth, John; Polhemus, Mark E.; Endy, Timothy P.; Cardenas, Washington; Mehta, Saurabh

    2014-01-01

    Dengue virus infection is the most widespread mosquito-borne viral infection in humans and has emerged as a serious global health challenge. In the absence of effective treatment and vaccine, host factors including nutritional status, which may alter disease progression, need investigation. The interplay between nutrition and other infections is well-established, and modulation of nutritional status often presents a simple low-cost method of interrupting transmission, reducing susceptibility, and/or ameliorating disease severity. This review examines the evidence on the role of micronutrients in dengue virus infection. We found critical issues and often inconsistent results across studies; this finding along with the lack of sufficient literature in this field have limited our ability to make any recommendations. However, vitamins D and E have shown promise in small supplementation trials. In summary, the role of micronutrients in dengue virus infection is an exciting research area and needs to be examined in well-designed studies with larger samples. PMID:25200269

  2. Prospects for dengue vaccines for travelers

    PubMed Central

    2016-01-01

    Travel-acquired dengue cases have been increasing as the overall global dengue burden has expanded. In Korea, imported dengue cases have been reported since 2000 when it first became a notifiable disease. During the first four months of 2016, three times more dengue cases were reported in Korea than during the same period the previous year. A safe and efficacious vaccine for travelers would be beneficial to prevent dengue disease in individual travelers and potentially decrease the risk of virus spread to non-endemic areas. Here, we summarize the characteristics of dengue vaccines for travelers and review dengue vaccines currently licensed or in clinical development. PMID:27489798

  3. Dengue antibodies in blood donors

    PubMed Central

    Ribas-Silva, Rejane Cristina; Eid, Andressa Ahmad

    2012-01-01

    Background Dengue is an urban arbovirus whose etiologic agent is a virus of the genus Flavorius with four distinct antigen serotypes (DENV-1, DENV-2, DENV-3 and DENV-4) that is transmitted to humans through the bite of the mosquito Aedes aegypti. The Campo Mourão region in Brazil is endemic for dengue fever. Obtective The aim of this study was to evaluate the presence of IgG and IgM antibodies specific to the four serotypes of dengue in donors of the blood donor service in the city of Campo Mourão. Methods Epidemiological records were evaluated and 4 mL of peripheral blood from 213 blood donors were collected in tubes without anticoagulant. Serum was then obtained and immunochromatographic tests were undertaken (Imuno-Rápido Dengue IgM/IgGTM). Individuals involved in the study answered a social and epidemiological questionnaire on data which included age, gender and diagnosis of dengue. Results Only three (1.4%) of the 213 blood tests were positive for IgG anti-dengue antibodies. No donors with IgM antibody, which identifies acute infection, were identified. Conclusions The results of the current analysis show that the introduction of quantitative or molecular serological methods to determine the presence of anti-dengue antibodies or the detection of the dengue virus in blood donors in endemic regions should be established so that the quality of blood transfusions is guaranteed. PMID:23049418

  4. Reemergence of dengue in Mauritius.

    PubMed

    Issack, Mohammad I; Pursem, Vidula N; Barkham, Timothy M S; Ng, Lee Ching; Inoue, Masafumi; Manraj, Shyam S

    2010-04-01

    Dengue reemerged in Mauritius in 2009 after an absence of >30 years, and >200 cases were confirmed serologically. Molecular studies showed that the outbreak was caused by dengue virus type 2. Phylogenetic analysis of the envelope gene identified 2 clades of the virus. No case of hemorrhagic fever was recorded.

  5. Dengue-1 virus isolation during first dengue fever outbreak on Easter Island, Chile.

    PubMed

    Perret, Cecilia; Abarca, Katia; Ovalle, Jimena; Ferrer, Pablo; Godoy, Paula; Olea, Andrea; Aguilera, Ximena; Ferrés, Marcela

    2003-11-01

    Dengue virus was detected for the first time in Chile, in an outbreak of dengue fever on Easter Island. The virus was isolated in tissue culture and characterized by reverse transcription-polymerase chain reaction as being dengue type 1.

  6. Development of dengue DNA vaccines.

    PubMed

    Danko, Janine R; Beckett, Charmagne G; Porter, Kevin R

    2011-09-23

    Vaccination with plasmid DNA against infectious pathogens including dengue is an active area of investigation. By design, DNA vaccines are able to elicit both antibody responses and cellular immune responses capable of mediating long-term protection. Great technical improvements have been made in dengue DNA vaccine constructs and trials are underway to study these in the clinic. The scope of this review is to highlight the rich history of this vaccine platform and the work in dengue DNA vaccines accomplished by scientists at the Naval Medical Research Center. This work resulted in the only dengue DNA vaccine tested in a clinical trial to date. Additional advancements paving the road ahead in dengue DNA vaccine development are also discussed.

  7. Human Immune Response to Dengue Infections

    DTIC Science & Technology

    1989-07-31

    lhuman Immune Response to Dengue Infections 12. PERSONAL AUTHOR(S) Francis A. Ennis 13a. TYPE OF REPORT 13b. TIME COVERED T14. DATE OF REPORT (Year, Month...Stimulation with live dengue virus of peripheral blood mononuclear cells from a dengue 4-immune donor generated virus-specific serotype cross-reactive CD4- CD8...class I-restricted cytotoxic T lymphocytes (CL) capable of lysing dengue virus-infected autologous fibroblasts and cells pulsed with dengue I

  8. Dengue human infection models to advance dengue vaccine development.

    PubMed

    Larsen, Christian P; Whitehead, Stephen S; Durbin, Anna P

    2015-12-10

    Dengue viruses (DENV) currently infect approximately 400 million people each year causing millions to seek care and overwhelming the health care infrastructure in endemic areas. Vaccines to prevent dengue and therapeutics to treat dengue are not currently available. The efficacy of the most advanced candidate vaccine against symptomatic dengue in general and DENV-2 in particular was much lower than expected, despite the ability of the vaccine to induce neutralizing antibody against all four DENV serotypes. Because seroconversion to the DENV serotypes following vaccination was thought to be indicative of induced protection, these results have made it more difficult to assess which candidate vaccines should or should not be evaluated in large studies in endemic areas. A dengue human infection model (DHIM) could be extremely valuable to down-select candidate vaccines or therapeutics prior to engaging in efficacy trials in endemic areas. Two DHIM have been developed to assess the efficacy of live attenuated tetravalent (LATV) dengue vaccines. The first model, developed by the Laboratory of Infectious Diseases at the U. S. National Institutes of Health, utilizes a modified DENV-2 strain DEN2Δ30. This virus was derived from the DENV-2 Tonga/74 that caused only very mild clinical infection during the outbreak from which it was recovered. DEN2Δ30 induced viremia in 100%, rash in 80%, and neutropenia in 27% of the 30 subjects to whom it was given. The Walter Reed Army Institute of Research (WRAIR) is developing a DHIM the goal of which is to identify DENV that cause symptomatic dengue fever. WRAIR has evaluated seven viruses and has identified two that meet dengue fever criteria. Both of these models may be very useful in the evaluation and down-selection of candidate dengue vaccines and therapeutics.

  9. Dengue and other flavivirus infections.

    PubMed

    Choumet, V; Desprès, Ph

    2015-08-01

    Flaviviruses are responsible for yellow fever, Zika fever and dengue, all of which are major human diseases found in tropical regions of the globe. They are zoonoses with a transmission cycle that involves primates as reservoirs and mosquitoes of the genus Aedes as vectors. The recent upsurge of urban epidemics of yellow fever, Zika fever and dengue has involved human-to-human transmission with mosquitoes as the vector. This paper is primarily concerned with dengue, which has become the pre-eminent arbovirosis in terms of public health.

  10. Dengue and dengue haemorrhagic fever: implications of host genetics.

    PubMed

    Chaturvedi, Umeshc; Nagar, Rachna; Shrivastava, Richa

    2006-07-01

    Little is known of the role of human leucocyte antigen (HLA) alleles or non-HLA alleles in determining resistance, susceptibility or the severity of acute viral infections. Dengue fever (DF) and dengue haemorrhagic fever (DHF) are suitable models for immunogenetic studies, yet only superficial efforts have been made to study dengue disease to date. DF and DHF can be caused by both primary and secondary infection by any of the four serotypes of the dengue virus. Differences in host susceptibility to infectious disease and disease severity cannot be attributed solely to the virus virulence. Variations in immune response, often associated with polymorphism in the human genome, can now be detected. Data on the influence of human genes in DF and DHF are discussed here in relation to (1) associations between HLA polymorphism and dengue disease susceptibility or resistance, (2) protective alleles influencing progression to severe disease, (3) alleles restricting CD4(+) and CD8(+) T lymphocytes, and (4) non-HLA genetic factors that may contribute to DHF evolution. Recent discoveries regarding genetic associations in other viral infections may provide clues to understanding the development of end-stage complications in dengue disease. The scanty positive data presented here indicate a need for detailed genetic studies in different ethnic groups in different countries during the acute phase of DF and DHF on a larger number of patients.

  11. Dengue fever and dengue haemorrhagic fever in adolescents and adults.

    PubMed

    Tantawichien, Terapong

    2012-05-01

    Dengue fever (DF) is endemic in tropical and subtropical zones and the prevalence is increasing across South-east Asia, Africa, the Western Pacific and the Americas. In recent years, the spread of unplanned urbanisation, with associated substandard housing, overcrowding and deterioration in water, sewage and waste management systems, has created ideal conditions for increased transmission of the dengue virus in tropical urban centres. While dengue infection has traditionally been considered a paediatric disease, the age distribution of dengue has been rising and more cases have been observed in adolescents and adults. Furthermore, the development of tourism in the tropics has led to an increase in the number of tourists who become infected, most of whom are adults. Symptoms and risk factors for dengue haemorrhagic fever (DHF) and severe dengue differ between children and adults, with co-morbidities and incidence in more elderly patients associated with greater risk of mortality. Treatment options for DF and DHF in adults, as for children, centre round fluid replacement (either orally or intravenously, depending on severity) and antipyretics. Further data are needed on the optimal treatment of adult patients.

  12. Recent advances in understanding dengue

    PubMed Central

    Yacoub, Sophie; Mongkolsapaya, Juthathip; Screaton, Gavin

    2016-01-01

    Dengue is an emerging threat to billions of people worldwide. In the last 20 years, the incidence has increased four-fold and this trend appears to be continuing. Caused by one of four viral serotypes, dengue can present as a wide range of clinical phenotypes with the severe end of the spectrum being defined by a syndrome of capillary leak, coagulopathy, and organ impairment. The pathogenesis of severe disease is thought to be in part immune mediated, but the exact mechanisms remain to be defined. The current treatment of dengue relies on supportive measures with no licensed therapeutics available to date. There have been recent advances in our understanding of a number of areas of dengue research, of which the following will be discussed in this review: the drivers behind the global dengue pandemic, viral structure and epitope binding, risk factors for severe disease and its pathogenesis, as well as the findings of recent clinical trials including therapeutics and vaccines. We conclude with current and future dengue control measures and key areas for future research. PMID:26918159

  13. Dengue viruses – an overview

    PubMed Central

    Bäck, Anne Tuiskunen; Lundkvist, Åke

    2013-01-01

    Dengue viruses (DENVs) cause the most common arthropod-borne viral disease in man with 50–100 million infections per year. Because of the lack of a vaccine and antiviral drugs, the sole measure of control is limiting the Aedes mosquito vectors. DENV infection can be asymptomatic or a self-limited, acute febrile disease ranging in severity. The classical form of dengue fever (DF) is characterized by high fever, headache, stomach ache, rash, myalgia, and arthralgia. Severe dengue, dengue hemorrhagic fever (DHF), and dengue shock syndrome (DSS) are accompanied by thrombocytopenia, vascular leakage, and hypotension. DSS, which can be fatal, is characterized by systemic shock. Despite intensive research, the underlying mechanisms causing severe dengue is still not well understood partly due to the lack of appropriate animal models of infection and disease. However, even though it is clear that both viral and host factors play important roles in the course of infection, a fundamental knowledge gap still remains to be filled regarding host cell tropism, crucial host immune response mechanisms, and viral markers for virulence. PMID:24003364

  14. Dengue vaccines: problems and prospects.

    PubMed

    Chaturvedi, U C; Shrivastava, Richa; Nagar, Rachna

    2005-05-01

    The extent of cumulative disease burden caused by dengue virus has attained an unprecedented level in recent times with sharp increase in the size of human population at risk. Dengue disease presents highly complex medical, economic and ecologic problems. The surge in publications on the development of dengue vaccines, taking advantage of new generation of biotechnology techniques indicates the profound interest and urgency in the scientific and medical communities in combating this disease. This review summarizes the importance of critical subjects like pathogenesis of dengue haemorrhagic fever and inadequacy of animal model that have adversely affected dengue vaccine development. Further, the remarkable progresses so far made in dengue vaccine research not only employing a diverse range of new strategies but also re-using old techniques to improve the existing vaccines, have been presented. The efficacy and safety of some of the new vaccine candidates have been evaluated and proven in human preclinical/clinical trials. Besides the technical advancement in vaccine development, vaccine safety and vaccine formulation have been examined.

  15. Dot enzyme immunoassay: an alternative diagnostic aid for dengue fever and dengue haemorrhagic fever.

    PubMed Central

    Cardosa, M. J.; Tio, P. H.

    1991-01-01

    A dot enzyme immunoassay (DEIA) for the detection of antibodies to dengue virus was tested for use as a tool in the presumptive diagnosis of dengue fever and dengue haemorrhagic fever. Paired sera from the following groups of patients were tested using the DEIA and the haemagglutination inhibition (HI) test: those with primary dengue fever; those experiencing a second dengue infection; and febrile patients who did not have dengue. The data obtained show that the DEIA can be effectively used at a serum dilution of 1:1000 to confirm presumptive recent dengue in patients with a second dengue infection. However, demonstration of seroconversion proved necessary for patients with primary dengue. At a serum dilution of 1:1000 the DEIA has a specificity of 97.3%. The role of this simple and rapid test in improving the effectivity of programmes for the control of dengue virus infection is discussed. PMID:1786623

  16. Acute disseminated encephalomyelitis in dengue viral infection.

    PubMed

    Wan Sulaiman, Wan Aliaa; Inche Mat, Liyana Najwa; Hashim, Hasnur Zaman; Hoo, Fan Kee; Ching, Siew Mooi; Vasudevan, Ramachandran; Mohamed, Mohd Hazmi; Basri, Hamidon

    2017-09-01

    Dengue is the most common arboviral disease affecting many countries worldwide. An RNA virus from the flaviviridae family, dengue has four antigenically distinct serotypes (DEN-1-DEN-4). Neurological involvement in dengue can be classified into dengue encephalopathy immune-mediated syndromes, encephalitis, neuromuscular or dengue muscle dysfunction and neuro-ophthalmic involvement. Acute disseminated encephalomyelitis (ADEM) is an immune mediated acute demyelinating disorder of the central nervous system following recent infection or vaccination. This monophasic illness is characterised by multifocal white matter involvement. Many dengue studies and case reports have linked ADEM with dengue virus infection but the association is still not clear. Therefore, this article is to review and discuss concerning ADEM in dengue as an immune-medicated neurological complication; and the management strategy required based on recent literature. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Scientists Create Mosquitoes Resistant to Dengue Virus

    MedlinePlus

    ... fullstory_163019.html Scientists Create Mosquitoes Resistant to Dengue Virus Hope is to eventually make the bugs ... say they have created mosquitoes resistant to the dengue virus, which might eventually help control the spread ...

  18. Safety Testing of Dengue-1 and Dengue-3 Seeds for Human Challenges, Unattenuated

    DTIC Science & Technology

    1987-03-16

    62770A870 AC 029 11. TITL.E (Include Security Classiftcation) (U) Safety Testing of Dengue -1 and Dengue -𔃽 Seeds for Human Challenges, Unatteuad 12...safety testing of a lot of dengue virus type 3 designated as: Dengue Virus Type 3 (Non-Attenuated) Strain CH-53489 Utilizing the testing procedures...Virus Strain: Dengue Virus *rype 3 (Non-Attenuated) Strain: CH-53489 B. Live Virus Vaccine Pool Designation: MFG Date: April J.984, LOT No. 1 C

  19. Dengue Virus Seroconversion in Travelers to Dengue-Endemic Areas.

    PubMed

    Olivero, Rosemary M; Hamer, Davidson H; MacLeod, William B; Benoit, Christine M; Sanchez-Vegas, Carolina; Jentes, Emily S; Chen, Lin H; Wilson, Mary E; Marano, Nina; Yanni, Emad A; Ooi, Winnie W; Karchmer, Adolf W; Kogelman, Laura; Barnett, Elizabeth D

    2016-11-02

    We conducted a prospective study to measure dengue virus (DENV) antibody seroconversion in travelers to dengue-endemic areas. Travelers seen in the Boston Area Travel Medicine Network planning to visit dengue-endemic countries for ≥ 2 weeks were enrolled from 2009 to 2010. Pre- and post-travel blood samples and questionnaires were collected. Post-travel sera were tested for anti-DENV IgG by indirect IgG enzyme-linked immunosorbent assay (ELISA) and anti-DENV IgM by capture IgM ELISA. Participants with positive post-travel anti-DENV IgG or IgM were tested for pre-travel anti-DENV IgG and IgM; they were excluded from the seroconversion calculation if either pre-travel anti-DENV IgG or IgM were positive. Paired sera and questionnaires were collected for 62% (589/955) of enrolled travelers. Most participants were 19-64 years of age, female, and white. The most common purposes of travel were tourism and visiting friends and relatives; most trips were to Asia or Africa. Median length of travel was 21 days. DENV antibody seroconversion by either anti-DENV IgM or IgG ELISA was 2.9-6.8%; lower range percent excluded potential false-positive anti-DENV IgG due to receipt of yellow fever or Japanese encephalitis vaccines at enrollment; upper range percent excluded proven false-positive anti-DENV IgM. Eighteen percent of those with seroconversion reported dengue-like symptoms. Seroconversion was documented for travel to Africa as well as countries and regions known to be highly dengue endemic (India, Brazil, southeast Asia). Given widespread risk of dengue, travel medicine counseling should include information on risk of dengue in endemic areas and advice on preventing insect bites and seeking prompt medical attention for febrile illness.

  20. Dengue Antibody and Zika: Friend or Foe?

    PubMed

    Durbin, Anna P

    2016-10-01

    Zika virus is a mosquito-borne Flavivirus related to dengue that is rapidly spreading through the Americas. This outbreak is occurring in dengue-endemic areas where the population has acquired antibodies to dengue. Recent studies reveal that preexisting dengue antibodies may have opposite effects on Zika infection, transmission, and clinical outcome. Discerning these effects is critical to a better understanding of Zika pathogenesis and the prevention of future outbreaks.

  1. Reviewing Dengue: Still a Neglected Tropical Disease?

    PubMed Central

    Horstick, Olaf; Tozan, Yesim; Wilder-Smith, Annelies

    2015-01-01

    Dengue is currently listed as a “neglected tropical disease” (NTD). But is dengue still an NTD or not? Classifying dengue as an NTD may carry advantages, but is it justified? This review considers the criteria for the definition of an NTD, the current diverse lists of NTDs by different stakeholders, and the commonalities and differences of dengue with other NTDs. We also review the current research gaps and research activities and the adequacy of funding for dengue research and development (R&D) (2003–2013). NTD definitions have been developed to a higher precision since the early 2000s, with the following main features: NTDs are characterised as a) poverty related, b) endemic to the tropics and subtropics, c) lacking public health attention, d) having poor research funding and shortcomings in R&D, e) usually associated with high morbidity but low mortality, and f) often having no specific treatment available. Dengue meets most of these criteria, but not all. Although dengue predominantly affects resource-limited countries, it does not necessarily only target the poor and marginalised in those countries. Dengue increasingly attracts public health attention, and in some affected countries it is now a high profile disease. Research funding for dengue has increased exponentially in the past two decades, in particular in the area of dengue vaccine development. However, despite advances in dengue research, dengue epidemics are increasing in frequency and magnitude, and dengue is expanding to new areas. Specific treatment and a highly effective vaccine remain elusive. Major research gaps exist in the area of integrated surveillance and vector control. Hence, although dengue differs from many of the NTDs, it still meets important criteria commonly used for NTDs. The current need for increased R&D spending, shared by dengue and other NTDs, is perhaps the key reason why dengue should continue to be considered an NTD. PMID:25928673

  2. [Hemorrhagic dengue fever after trip to Malaysia].

    PubMed

    Hafner, C; Koellner, K; Vogt, T; Landthaler, M; Szeimies, R-M

    2006-08-01

    A 39-year-old patient developed a disseminated rash with scattered petechiae, fever, malaise and arthralgia after a trip to Malaysia. The patient displayed increasing dengue IgG titers and borderline dengue IgM titers. Dengue fever with a hemorrhagic course is a rare condition in adult patients. Patients who have previously had dengue fever and retained non-neutralizing heterotypic antibodies are more likely to develop this complication via the phenomenon of antibody-dependent enhancement.

  3. Randomness of Dengue Outbreaks on the Equator.

    PubMed

    Chen, Yirong; Cook, Alex R; Lim, Alisa X L

    2015-09-01

    A simple mathematical model without seasonality indicated that the apparently chaotic dengue epidemics in Singapore have characteristics similar to epidemics resulting from chance. Randomness as a sufficient condition for patterns of dengue epidemics in equatorial regions calls into question existing explanations for dengue outbreaks there.

  4. Dengue maculopathy: a case report.

    PubMed

    Tan, S Y; Kumar, G; Surrun, S K; Ong, Y Y

    2007-01-01

    Dengue fever is endemic in many countries of South East Asia. In spite of the occasional epidemics, dengue maculopathy remains a rare entity. A 31-year-old gentleman was admitted with a 6-day history of fever, generalised rash, headache and myalgia after a trip to Malaysia. There were no bleeding manifestations. The lowest platelet count was 71 x 10,000/ml, the haematocrit was 42.7%, and dengue serology was positive. On the 8th day of illness, he complained of bilateral blurred vision. Detailed visual examination showed visual acuity of right eye 6/30 and left eye 6/50. Fundoscopy revealed dilated veins, hyperaemic optic discs, flame and blot haemorrhages, soft exudates and macular ischaemia. After a course of high-dose steroids, the visual acuity as well as colour vision improved markedly. The pathology of maculopathy is not obvious in this case, but an immunological reaction is suspected. There is a risk of residual visual impairment, and there is no definitive treatment. The use of high-dose steroids seemed to improve visual acuity and colour vision. However, it is not known whether immunosuppression improves the prognosis. Time for resolution is from 8 weeks to 4 months. Since there is an increase in the incidence of dengue fever in our region, coupled with rising international travel, one could postulate that global incidence of dengue-related maculopathy may become significant. Ocular complications associated with dengue fever are rare but may result in permanent visual impairment. Dengue fever should be suspected in travellers, particularly those returning from endemic areas, and they should be systematically screened for maculopathy when visual disturbances arise.

  5. Climate and Dengue Transmission: Evidence and Implications

    PubMed Central

    Comrie, Andrew C.; Ernst, Kacey

    2013-01-01

    Background: Climate influences dengue ecology by affecting vector dynamics, agent development, and mosquito/human interactions. Although these relationships are known, the impact climate change will have on transmission is unclear. Climate-driven statistical and process-based models are being used to refine our knowledge of these relationships and predict the effects of projected climate change on dengue fever occurrence, but results have been inconsistent. Objective: We sought to identify major climatic influences on dengue virus ecology and to evaluate the ability of climate-based dengue models to describe associations between climate and dengue, simulate outbreaks, and project the impacts of climate change. Methods: We reviewed the evidence for direct and indirect relationships between climate and dengue generated from laboratory studies, field studies, and statistical analyses of associations between vectors, dengue fever incidence, and climate conditions. We assessed the potential contribution of climate-driven, process-based dengue models and provide suggestions to improve their performance. Results and Discussion: Relationships between climate variables and factors that influence dengue transmission are complex. A climate variable may increase dengue transmission potential through one aspect of the system while simultaneously decreasing transmission potential through another. This complexity may at least partly explain inconsistencies in statistical associations between dengue and climate. Process-based models can account for the complex dynamics but often omit important aspects of dengue ecology, notably virus development and host–species interactions. Conclusion: Synthesizing and applying current knowledge of climatic effects on all aspects of dengue virus ecology will help direct future research and enable better projections of climate change effects on dengue incidence. Citation: Morin CW, Comrie AC, Ernst KC. 2013. Climate and dengue transmission

  6. Human Immune Response to Dengue Infections

    DTIC Science & Technology

    1988-07-31

    Security Classification) (U) Human Immune Response to Dengue Infections 12. PERSONAL AUTHOR(S) Francis A. Ennis 13a. TYPE OF’REPORTn 13b. TIME COVERED 14...8217SUBJECT TERMS (Continue on reverse if necessary and identify by Nock rumber) FIELD GROUP SUB-GROUP RA .1, Dengue virus, T lymphopytes. 06 03 InB-GROP1.In...responses to dengue antigens in vitro to elucidate the possible role of T lymphocytes in the pathogeneeis of dengue hemorrhagic fever and dengue

  7. Application of revised dengue classification criteria as a severity marker of dengue viral infection in Indonesia.

    PubMed

    Basuki, Parwati Setiono; Budiyanto; Puspitasari, Dwiyanti; Husada, Dominicus; Darmowandowo, Widodo; Ismoedijanto; Soegijanto, Soegeng; Yamanaka, Atsushi

    2010-09-01

    A prospective study of dengue infected patients at Dr.Soetomo Hospital pediatric ward was carried out from October 2008 to April 2009 to evaluate the revised dengue classification system proposed by the Dengue Control (DENCO), for early detection of severe dengue infected patients using the WHO classification system for comparison, with the addition of clinical interventions as a tool to grade for severity. One hundred forty-five patients were included in the study. Using the WHO classification system, 122 cases (84.1%) were classified as having non-severe dengue, of which 70 (48.3%) were classified as having dengue fever (DF), 39 (26.9%) as having dengue hemorrhagic fever (DHF) grade I, and 13 (9%) as having DHF grade II. Twenty-three (15.9%) were classified as having severe dengue, of which 16 (11%) were classified as having DHF grade III and 7 (4.8%) as having DHF grade IV. With clinical interventions included, 8 cases (6.6%) originally classified as having non-severe dengue infection were reclassified as having severe infection (sensitivity = 74%, specificity = 100%, likelihood ratio (-) = 0.26). Using the new dengue classification system, 117 cases (80.7%) were classified as having non-severe dengue infection, of which 79 (54.5%) were classified as having dengue without warning signs and 38 (26.2%) were classified as having dengue with warning signs, while 28 (19.3%) were classified as having severe dengue infection. Using clinical intervention, 4 cases (3.4%) which were originally classified as having non-severe dengue infection were reclassified as having severe dengue infection (sensitivity = 88%, specificity = 99%, likelihood ratio (+) = 98.88, likelihood ratio (-) = 0.13). Binary logistic regression showed the revised dengue classification system (p = 0.000, Wald:22.446) was better in detecting severe dengue infections than the WHO classification system (p = 0.175, Wald:6.339).

  8. Critical issues in dengue vaccine development.

    PubMed

    Thomas, Stephen J; Endy, Timothy P

    2011-10-01

    Dengue is currently an expanding global health problem. Development of an effective tetravalent dengue vaccine is considered a high public health priority. The uniqueness of the dengue viruses (DENVs) and the spectrum of disease resulting from infection has made dengue vaccine development difficult. This review focuses on the current critical issues in dengue vaccine development. DENVs are arboviral flaviviruses transmitted by Aedes mosquitoes causing a spectrum of clinical disease. DENV infections are a significant global health problem; the WHO estimates that more than 120 countries have endemic DENV transmission resulting in 70-500 million infections, 2.1 million clinically severe cases, and 21 000 deaths annually. There are currently no licensed antivirals or vaccines to treat or prevent dengue. The DENV-host interaction of infection is unique with severe disease a consequence of sequential dengue infection, viral immune evasion, host antibody enhancement, host immune activation, and genetic predisposition. This unique pathogen-host interaction complicates dengue vaccine development and creates provocative questions in vaccine development such as identifying markers of protective immunogenicity, the potential role of antibody in vaccine failures, and the possible impact of large-scale vaccination on the evolution of wild-type DENV. Dengue is a unique and complex disease; developing a dengue vaccine has proven equally complex. In this review, the authors discuss issues that will prove to be critical to the success or failure of the dengue vaccine development effort.

  9. Reemergence of Dengue in Southern Texas, 2013

    PubMed Central

    Thomas, Dana L.; Santiago, Gilberto A.; Abeyta, Roman; Hinojosa, Steven; Torres-Velasquez, Brenda; Adam, Jessica K.; Evert, Nicole; Caraballo, Elba; Hunsperger, Elizabeth; Muñoz-Jordán, Jorge L.; Smith, Brian; Banicki, Alison; Tomashek, Kay M.; Gaul, Linda

    2016-01-01

    During a dengue epidemic in northern Mexico, enhanced surveillance identified 53 laboratory-positive cases in southern Texas; 26 (49%) patients acquired the infection locally, and 29 (55%) were hospitalized. Of 83 patient specimens that were initially IgM negative according to ELISA performed at a commercial laboratory, 14 (17%) were dengue virus positive by real-time reverse transcription PCR performed at the Centers for Disease Control and Prevention. Dengue virus types 1 and 3 were identified, and molecular phylogenetic analysis demonstrated close identity with viruses that had recently circulated in Mexico and Central America. Of 51 household members of 22 dengue case-patients who participated in household investigations, 6 (12%) had been recently infected with a dengue virus and reported no recent travel, suggesting intrahousehold transmission. One household member reported having a recent illness consistent with dengue. This outbreak reinforces emergence of dengue in southern Texas, particularly when incidence is high in northern Mexico. PMID:27191223

  10. Trends in clinical trials of dengue vaccine

    PubMed Central

    Marimuthu, Priya; Ravinder, Jamuna Rani

    2016-01-01

    Dengue is one of the most important vector-borne disease and an increasing problem worldwide because of current globalization trends. Roughly, half the world's population lives in dengue endemic countries, and nearly 100 million people are infected annually with dengue. India has the highest burden of the disease with 34% of the global cases. In the context of an expanding and potentially fatal infectious disease without effective prevention or specific treatment, the public health value of a protective vaccine is clear. There is no licensed dengue vaccine is available still, but several vaccines are under development. Keeping in view the rise in dengue prevalence globally, there is a need to increase clinical drug and vaccine research on dengue. This paper briefly reviews on the development and current status of dengue vaccine to provide information to policymakers, researchers, and public health experts to design and implement appropriate vaccine for prophylactic intervention. PMID:27843790

  11. Transfusion support in patients with dengue fever.

    PubMed

    Kaur, Paramjit; Kaur, Gagandeep

    2014-09-01

    Dengue fever has emerged as a global public health problem in the recent decades. The clinical spectrum of the disease ranges from dengue fever to dengue hemorrhagic fever and dengue shock syndrome. The disease is characterized by increased capillary permeability, thrombocytopenia and coagulopathy. Thrombocytopenia with hemorrhagic manifestations warrants platelet transfusions. There is lack of evidence-based guidelines for transfusion support in patients with dengue fever. This contributes to inappropriate use of blood components and blood centers constantly face the challenge of inventory management during dengue outbreaks. The current review is aimed to highlight the role of platelets and other blood components in the management of dengue. The review was performed after searching relevant published literature in PubMed, Science Direct, Google scholar and various text books and journal articles.

  12. Reemergence of Dengue in Southern Texas, 2013.

    PubMed

    Thomas, Dana L; Santiago, Gilberto A; Abeyta, Roman; Hinojosa, Steven; Torres-Velasquez, Brenda; Adam, Jessica K; Evert, Nicole; Caraballo, Elba; Hunsperger, Elizabeth; Muñoz-Jordán, Jorge L; Smith, Brian; Banicki, Alison; Tomashek, Kay M; Gaul, Linda; Sharp, Tyler M

    2016-06-01

    During a dengue epidemic in northern Mexico, enhanced surveillance identified 53 laboratory-positive cases in southern Texas; 26 (49%) patients acquired the infection locally, and 29 (55%) were hospitalized. Of 83 patient specimens that were initially IgM negative according to ELISA performed at a commercial laboratory, 14 (17%) were dengue virus positive by real-time reverse transcription PCR performed at the Centers for Disease Control and Prevention. Dengue virus types 1 and 3 were identified, and molecular phylogenetic analysis demonstrated close identity with viruses that had recently circulated in Mexico and Central America. Of 51 household members of 22 dengue case-patients who participated in household investigations, 6 (12%) had been recently infected with a dengue virus and reported no recent travel, suggesting intrahousehold transmission. One household member reported having a recent illness consistent with dengue. This outbreak reinforces emergence of dengue in southern Texas, particularly when incidence is high in northern Mexico.

  13. Points for Consideration for dengue vaccine introduction - recommendations by the Dengue Vaccine Initiative.

    PubMed

    Lim, Jacqueline Kyungah; Lee, Yong-Seok; Wilder-Smith, Annelies; Thiry, Georges; Mahoney, Richard; Yoon, In-Kyu

    2016-01-01

    Dengue is a public health problem in the tropics and subtropics. There are several vaccine candidates in clinical development. However, there may be gaps in the new vaccine introduction after vaccine licensure before it becomes available in developing countries. In anticipation of the first dengue vaccine candidate to be licensed, Dengue Vaccine Initiative (DVI) and, its predecessor, Pediatric Dengue Vaccine Initiative (PDVI) have been working on points for consideration to accelerate evidence-based dengue vaccine introduction, once a vaccine becomes available. In this paper, we review the history of PDVI and its successor, the DVI, and elaborate on the points of consideration for dengue vaccine introduction.

  14. Dengue virus identification by transmission electron microscopy and molecular methods in fatal dengue hemorrhagic fever.

    PubMed

    Limonta, D; Falcón, V; Torres, G; Capó, V; Menéndez, I; Rosario, D; Castellanos, Y; Alvarez, M; Rodríguez-Roche, R; de la Rosa, M C; Pavón, A; López, L; González, K; Guillén, G; Diaz, J; Guzmán, M G

    2012-12-01

    Dengue virus is the most significant virus transmitted by arthropods worldwide and may cause a potentially fatal systemic disease named dengue hemorrhagic fever. In this work, dengue virus serotype 4 was detected in the tissues of one fatal dengue hemorrhagic fever case using electron immunomicroscopy and molecular methods. This is the first report of dengue virus polypeptides findings by electron immunomicroscopy in human samples. In addition, not-previously-documented virus-like particles visualized in spleen, hepatic, brain, and pulmonary tissues from a dengue case are discussed.

  15. [Society, economy, inequities and dengue].

    PubMed

    Kouri, Gustavo; Pelegrino, José L; Munster, Blanca María; Guzmán, María G

    2007-01-01

    Dengue and dengue hemorrhagic fever in the Americas have been on the rise throughout the 1990s, with the highest number -over one million cases- reported in 2002. This paper analyzed the situation of dengue in the region and discussed the determining factors that account for the rise of the disease, making emphasis on socioeconomic factors, such as poverty, inequality, migrations and the lack of access to basic services, which are the most influential in perpetuating this disease in most countries. Considering that a safe and accessible vaccine is now unavailable, basic principles of vector control combined with political willingness, inter-sectoral involvement, active community participation and the tightening of health legislation were also examined as the only viable solution at present.

  16. Climate and dengue transmission: evidence and implications.

    PubMed

    Morin, Cory W; Comrie, Andrew C; Ernst, Kacey

    2013-01-01

    Climate influences dengue ecology by affecting vector dynamics, agent development, and mosquito/human interactions. Although these relationships are known, the impact climate change will have on transmission is unclear. Climate-driven statistical and process-based models are being used to refine our knowledge of these relationships and predict the effects of projected climate change on dengue fever occurrence, but results have been inconsistent. We sought to identify major climatic influences on dengue virus ecology and to evaluate the ability of climate-based dengue models to describe associations between climate and dengue, simulate outbreaks, and project the impacts of climate change. We reviewed the evidence for direct and indirect relationships between climate and dengue generated from laboratory studies, field studies, and statistical analyses of associations between vectors, dengue fever incidence, and climate conditions. We assessed the potential contribution of climate-driven, process-based dengue models and provide suggestions to improve their performance. Relationships between climate variables and factors that influence dengue transmission are complex. A climate variable may increase dengue transmission potential through one aspect of the system while simultaneously decreasing transmission potential through another. This complexity may at least partly explain inconsistencies in statistical associations between dengue and climate. Process-based models can account for the complex dynamics but often omit important aspects of dengue ecology, notably virus development and host-species interactions. Synthesizing and applying current knowledge of climatic effects on all aspects of dengue virus ecology will help direct future research and enable better projections of climate change effects on dengue incidence.

  17. Controlling Dengue with Vaccines in Thailand

    PubMed Central

    Chao, Dennis L.; Halstead, Scott B.; Halloran, M. Elizabeth; Longini, Ira M.

    2012-01-01

    Background Dengue is a mosquito-borne infectious disease that constitutes a growing global threat with the habitat expansion of its vectors Aedes aegyti and A. albopictus and increasing urbanization. With no effective treatment and limited success of vector control, dengue vaccines constitute the best control measure for the foreseeable future. With four interacting dengue serotypes, the development of an effective vaccine has been a challenge. Several dengue vaccine candidates are currently being tested in clinical trials. Before the widespread introduction of a new dengue vaccine, one needs to consider how best to use limited supplies of vaccine given the complex dengue transmission dynamics and the immunological interaction among the four dengue serotypes. Methodology/Principal Findings We developed an individual-level (including both humans and mosquitoes), stochastic simulation model for dengue transmission and control in a semi-rural area in Thailand. We calibrated the model to dengue serotype-specific infection, illness and hospitalization data from Thailand. Our simulations show that a realistic roll-out plan, starting with young children then covering progressively older individuals in following seasons, could reduce local transmission of dengue to low levels. Simulations indicate that this strategy could avert about 7,700 uncomplicated dengue fever cases and 220 dengue hospitalizations per 100,000 people at risk over a ten-year period. Conclusions/Significance Vaccination will have an important role in controlling dengue. According to our modeling results, children should be prioritized to receive vaccine, but adults will also need to be vaccinated if one wants to reduce community-wide dengue transmission to low levels. PMID:23145197

  18. Controlling dengue with vaccines in Thailand.

    PubMed

    Chao, Dennis L; Halstead, Scott B; Halloran, M Elizabeth; Longini, Ira M

    2012-01-01

    Dengue is a mosquito-borne infectious disease that constitutes a growing global threat with the habitat expansion of its vectors Aedes aegyti and A. albopictus and increasing urbanization. With no effective treatment and limited success of vector control, dengue vaccines constitute the best control measure for the foreseeable future. With four interacting dengue serotypes, the development of an effective vaccine has been a challenge. Several dengue vaccine candidates are currently being tested in clinical trials. Before the widespread introduction of a new dengue vaccine, one needs to consider how best to use limited supplies of vaccine given the complex dengue transmission dynamics and the immunological interaction among the four dengue serotypes. We developed an individual-level (including both humans and mosquitoes), stochastic simulation model for dengue transmission and control in a semi-rural area in Thailand. We calibrated the model to dengue serotype-specific infection, illness and hospitalization data from Thailand. Our simulations show that a realistic roll-out plan, starting with young children then covering progressively older individuals in following seasons, could reduce local transmission of dengue to low levels. Simulations indicate that this strategy could avert about 7,700 uncomplicated dengue fever cases and 220 dengue hospitalizations per 100,000 people at risk over a ten-year period. Vaccination will have an important role in controlling dengue. According to our modeling results, children should be prioritized to receive vaccine, but adults will also need to be vaccinated if one wants to reduce community-wide dengue transmission to low levels.

  19. Policymakers' views on dengue fever/dengue haemorrhagic fever and the need for dengue vaccines in four southeast Asian countries.

    PubMed

    DeRoeck, Denise; Deen, Jacqueline; Clemens, John D

    2003-12-08

    A survey of policymakers and other influential professionals in four southeast Asian countries (Cambodia, Indonesia, Philippines and Vietnam) was conducted to determine policymakers' views on the public health importance of dengue fever and dengue haemorrhagic fever (DHF), the need for a vaccine and the determinants influencing its potential introduction. The survey, which involved face-to-face interviews with policymakers, health programme managers, researchers, opinion leaders and other key informants, revealed an almost uniformly high level of concern about dengue fever/DHF and a high perceived need for a dengue vaccine. Several characteristics of the disease contribute to this high sense of priority, including its geographic spread, occurrence in outbreaks, the recurrent risk of infection each dengue season, its severity and the difficulty in diagnosis and management, its urban predominance, its burden on hospitals, and its economic toll on governments and families. Research felt to be key to future decision-making regarding dengue vaccine introduction include: disease surveillance studies, in-country vaccine trials or pilot projects, and studies on the economic burden of dengue and the cost-effectiveness of dengue vaccines. The results suggest favourable conditions for public and private sector markets for dengue vaccines and the need for creative financing strategies to ensure their accessibility to poor children in dengue-endemic countries.

  20. Dengue haemorrhagic fever or dengue shock syndrome in children

    PubMed Central

    2015-01-01

    Introduction Dengue haemorrhagic fever and dengue shock syndrome are major causes of hospital admission and mortality in children. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical question: What are the effects of supportive treatments for dengue haemorrhagic fever or dengue shock syndrome in children? We searched: Medline, Embase, The Cochrane Library, and other important databases up to March 2014 (BMJ Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found nine studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: adding blood component transfusion to standard intravenous fluids; adding corticosteroids or intravenous immunoglobulin to standard intravenous fluids; and crystalloids versus colloids. PMID:25860404

  1. The Dengue Vaccine Pipeline: Implications for the Future of Dengue Control

    PubMed Central

    Schwartz, Lauren M.; Halloran, M. Elizabeth; Durbin, Anna P.; Longini, Ira M.

    2015-01-01

    Dengue has become the most rapidly expanding mosquito-borne infectious disease on the planet, surpassing malaria and infecting at least 390 million people per year. There is no effective treatment for dengue illness other than supportive care, especially for severe cases. Symptoms can be mild or life-threatening as in dengue hemorrhagic fever and dengue shock syndrome. Vector control has been only partially successful in decreasing dengue transmission. The potential use of safe and effective tetravalent dengue vaccines is an attractive addition to prevent disease or minimize the possibility of epidemics. There are currently no licensed dengue vaccines. This review summarizes the current status of all dengue vaccine candidates in clinical evaluation. Currently five candidate vaccines are in human clinical trials. One has completed two Phase III trials, two are in Phase II trials, and three are in Phase I testing. PMID:25989449

  2. Surveillance for Dengue and Dengue-Associated Neurologic Syndromes in the United States

    PubMed Central

    Waterman, Stephen H.; Margolis, Harold S.; Sejvar, James J.

    2015-01-01

    Autochthonous dengue virus transmission has occurred in the continental United States with increased frequency during the last decade; the principal vector, Aedes aegypti, has expanded its geographic distribution in the southern United States. Dengue, a potentially fatal arboviral disease, is underreported, and US clinicians encountering patients with acute febrile illness consistent with dengue are likely to not be fully familiar with dengue diagnosis and management. Recently, investigators suggested that an outbreak of dengue likely occurred in Houston during 2003 based on retrospective laboratory testing of hospitalized cases with encephalitis and aseptic meningitis. Although certain aspects of the Houston testing results and argument for local transmission are doubtful, the report highlights the importance of prospective surveillance for dengue in Aedes-infested areas of the United States, the need for clinical training on dengue and its severe manifestations, and the need for laboratory testing in domestic patients presenting with febrile neurologic illness in these regions to include dengue. PMID:25371183

  3. Is drought helping or killing dengue? Investigation of spatiotemporal relationship between dengue fever and drought

    NASA Astrophysics Data System (ADS)

    Lee, Chieh-Han; Yu, Hwa-Lung

    2015-04-01

    Dengue Fever is a vector-borne disease that is transmitted between human and mosquitos in tropical and sub-tropical regions. Previous studies have found significant relationship between the epidemic of dengue cases and climate variables, especially temperature and precipitation. Besides, the natural phenomena (e.g., drought) are considered that significantly drop the number of dengue cases by killing vector's breeding environment. However, in Kaohsiung City, Taiwan, there are evidences that the temporal pattern of dengue is correlated to drought events. Kaohsiung City experienced two main dengue outbreaks in 2002 and 2014 that both years were confirmed with serious drought. Especially in 2014, Kaohsiung City was suffered from extremely dengue outbreak in 2014 that reported the highest number of dengue cases in the history. This study constructs the spatiotemporal model of dengue incidences and index of drought events (Standardized Precipitation Index, SPI) based on the distributed lag nonlinear model (DLNM). Other meteorological measures are also included in the analysis.

  4. Surveillance for dengue and dengue-associated neurologic syndromes in the United States.

    PubMed

    Waterman, Stephen H; Margolis, Harold S; Sejvar, James J

    2015-05-01

    Autochthonous dengue virus transmission has occurred in the continental United States with increased frequency during the last decade; the principal vector, Aedes aegypti, has expanded its geographic distribution in the southern United States. Dengue, a potentially fatal arboviral disease, is underreported, and US clinicians encountering patients with acute febrile illness consistent with dengue are likely to not be fully familiar with dengue diagnosis and management. Recently, investigators suggested that an outbreak of dengue likely occurred in Houston during 2003 based on retrospective laboratory testing of hospitalized cases with encephalitis and aseptic meningitis. Although certain aspects of the Houston testing results and argument for local transmission are doubtful, the report highlights the importance of prospective surveillance for dengue in Aedes-infested areas of the United States, the need for clinical training on dengue and its severe manifestations, and the need for laboratory testing in domestic patients presenting with febrile neurologic illness in these regions to include dengue.

  5. The dengue vaccine pipeline: Implications for the future of dengue control.

    PubMed

    Schwartz, Lauren M; Halloran, M Elizabeth; Durbin, Anna P; Longini, Ira M

    2015-06-26

    Dengue has become the most rapidly expanding mosquito-borne infectious disease on the planet, surpassing malaria and infecting at least 390 million people per year. There is no effective treatment for dengue illness other than supportive care, especially for severe cases. Symptoms can be mild or life-threatening as in dengue hemorrhagic fever and dengue shock syndrome. Vector control has been only partially successful in decreasing dengue transmission. The potential use of safe and effective tetravalent dengue vaccines is an attractive addition to prevent disease or minimize the possibility of epidemics. There are currently no licensed dengue vaccines. This review summarizes the current status of all dengue vaccine candidates in clinical evaluation. Currently five candidate vaccines are in human clinical trials. One has completed two Phase III trials, two are in Phase II trials, and three are in Phase I testing.

  6. Virulence Markers of Dengue Viruses

    DTIC Science & Technology

    1990-02-20

    for accurate detection of viral antigen by EIA, cells were cultured in specially treated tissue culture plates " Primaria " (Falcon product...Approximately 1 x 10 cells per well were plated into the 96 well " primaria " plates. Cell cultures were infected with several isolates of dengue-2 virus at the

  7. Drivers of Dengue Intrahost Evolution.

    PubMed

    Simon-Lorière, Etienne; Vignuzzi, Marco

    2017-09-13

    RNA viruses circulate as rapidly evolving swarms of related variants, and their evolutionary dynamics within hosts may be key to understanding virus emergence. In this issue of Cell Host & Microbe, Parameswaran et al. (2017) combine next-generation sequencing and functional studies to characterize viral populations in acute dengue infections. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Cardiac Manifestation in Dengue Fever.

    PubMed

    Arora, Mohit; Patil, Rekha S

    2016-07-01

    To study the cardiac manifestations of the dengue fever. This one year descriptive study was undertaken at KLES Dr. Prabhakar Kore Hospital and Medical Research Centre, Belgaum under the Department of Medicine. A total of 120 patients with either dengue IgM or IgM and IgG were studied. The assessment of cardiac manifestations was done based on electrocardiogram, 2D echocardiography and cardiac enzymes. Of the 120 patients, 85 (70.83%) were males and the male to female ratio was 2.4:1. The mean age of the patients was 33.02 ± 12.71 years. The commonest clinical presentation was myalgia (97.5%) followed by fever (92.5%). On clinical examination 33.33% of the patients had petecheia and only 9 patients having active bleeding manifestation at the time of presentation. A raised CK-MB and Troponin I was observed in 33.3% and 26.7% patients ECG findings revealed normal rhythm among 95% with 15.8% of them having an abnormal heart rate. Rhythm disturbance was noted in 5% of the patients with AV block being the most common (66.67%). Cardiac manifestation in the form of myocarditis was observed in 37.50% of the patients with a positive correlation with the severity of the dengue fever defined as by W.H.O. criteria. Patients with dengue fever are at high risk of developing myocarditis and rhythm disturbance and therefore require a close cardiac monitoring.

  9. Antibody response to dengue virus.

    PubMed

    Cedillo-Barrón, Leticia; García-Cordero, Julio; Bustos-Arriaga, José; León-Juárez, Moisés; Gutiérrez-Castañeda, Benito

    2014-09-01

    In this review, we discuss the current knowledge of the role of the antibody response against dengue virus and highlight novel insights into targets recognized by the human antibody response. We also discuss how the balance of pathological and protective antibody responses in the host critically influences clinical aspects of the disease. Copyright © 2014 Institut Pasteur. All rights reserved.

  10. Dengue-1 Virus Isolation during First Dengue Fever Outbreak on Easter Island, Chile

    PubMed Central

    Abarca, Katia; Ovalle, Jimena; Ferrer, Pablo; Godoy, Paula; Olea, Andrea; Aguilera, Ximena; Ferrés, Marcela

    2003-01-01

    Dengue virus was detected for the first time in Chile, in an outbreak of dengue fever on Easter Island. The virus was isolated in tissue culture and characterized by reverse transcription–polymerase chain reaction as being dengue type 1. PMID:14718094

  11. Dengue human infection models supporting drug development.

    PubMed

    Whitehorn, James; Van, Vinh Chau Nguyen; Simmons, Cameron P

    2014-06-15

    Dengue is a arboviral infection that represents a major global health burden. There is an unmet need for effective dengue therapeutics to reduce symptoms, duration of illness and incidence of severe complications. Here, we consider the merits of a dengue human infection model (DHIM) for drug development. A DHIM could allow experimentally controlled studies of candidate therapeutics in preselected susceptible volunteers, potentially using smaller sample sizes than trials that recruited patients with dengue in an endemic country. In addition, the DHIM would assist the conduct of intensive pharmacokinetic and basic research investigations and aid in determining optimal drug dosage. Furthermore, a DHIM could help establish proof of concept that chemoprophylaxis against dengue is feasible. The key challenge in developing the DHIM for drug development is to ensure the model reliably replicates the typical clinical and laboratory features of naturally acquired, symptomatic dengue. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America.

  12. Epidemiological Scenario of Dengue in Brazil

    PubMed Central

    Fares, Rafaelle C. G.; Souza, Katia P. R.; Añez, Germán; Rios, Maria

    2015-01-01

    Dengue is the most important reemerging mosquito-borne viral disease worldwide. It is caused by any of four Dengue virus types or serotypes (DENV-1 to DENV-4) and is transmitted by mosquitoes from the genus Aedes. Ecological changes have favored the geographic expansion of the vector and, since the dengue pandemic in the Asian and Pacific regions, the infection became widely distributed worldwide, reaching Brazil in 1845. The incidence of dengue in Brazil has been frequently high, and the number of cases in the country has at some point in time represented up to 60% of the dengue reported cases worldwide. This review addresses vector distribution, dengue outbreaks, circulating serotypes and genotypes, and prevention approaches being utilized in Brazil. PMID:26413514

  13. Epidemiological Scenario of Dengue in Brazil.

    PubMed

    Fares, Rafaelle C G; Souza, Katia P R; Añez, Germán; Rios, Maria

    2015-01-01

    Dengue is the most important reemerging mosquito-borne viral disease worldwide. It is caused by any of four Dengue virus types or serotypes (DENV-1 to DENV-4) and is transmitted by mosquitoes from the genus Aedes. Ecological changes have favored the geographic expansion of the vector and, since the dengue pandemic in the Asian and Pacific regions, the infection became widely distributed worldwide, reaching Brazil in 1845. The incidence of dengue in Brazil has been frequently high, and the number of cases in the country has at some point in time represented up to 60% of the dengue reported cases worldwide. This review addresses vector distribution, dengue outbreaks, circulating serotypes and genotypes, and prevention approaches being utilized in Brazil.

  14. Hemophagocytic syndrome in classic dengue Fever.

    PubMed

    Ray, Sayantan; Kundu, Supratip; Saha, Manjari; Chakrabarti, Prantar

    2011-10-01

    A 24-year-old previously healthy girl presented with persistent fever, headache, and jaundice. Rapid-test anti-dengue virus IgM antibody was positive but anti-dengue IgG was nonreactive, which is suggestive of primary dengue infection. There was clinical deterioration during empiric antibiotic and symptomatic therapy. Bone marrow examination demonstrated the presence of hemophagocytosis. Diagnosis of dengue fever with virus-associated hemophagocytic syndrome was made according to the diagnostic criteria of the HLH 2004 protocol of the Histiocyte Society. The patient recovered with corticosteroid therapy. A review of literature revealed only a handful of case reports that showed the evidence that this syndrome is caused by dengue virus. Our patient is an interesting case of hemophagocytic syndrome associated with classic dengue fever and contributes an additional case to the existing literature on this topic. This case highlights the need for increased awareness even in infections not typically associated with hemophagocytic syndrome.

  15. The global distribution and burden of dengue

    PubMed Central

    Bhatt, Samir; Gething, Peter W.; Brady, Oliver J.; Messina, Jane P.; Farlow, Andrew W.; Moyes, Catherine L.; Drake, John M.; Brownstein, John S.; Hoen, Anne G.; Sankoh, Osman; Myers, Monica F.; George, Dylan B.; Jaenisch, Thomas; Wint, G.R. William; Simmons, Cameron P.; Scott, Thomas W.; Farrar, Jeremy J.; Hay, Simon I.

    2013-01-01

    Dengue is a systemic viral infection transmitted between humans by Aedes mosquitoes1. For some patients dengue is a life-threatening illness2. There are currently no licensed vaccines or specific therapeutics, and substantial vector control efforts have not stopped its rapid emergence and global spread3. The contemporary worldwide distribution of the risk of dengue virus infection4 and its public health burden are poorly known2,5. Here we undertake an exhaustive assembly of known records of dengue occurrence worldwide, and use a formal modelling framework to map the global distribution of dengue risk. We then pair the resulting risk map with detailed longitudinal information from dengue cohort studies and population surfaces to infer the public health burden of dengue in 2010. We predict dengue to be ubiquitous throughout the tropics, with local spatial variations in risk influenced strongly by rainfall, temperature and the degree of urbanisation. Using cartographic approaches, we estimate there to be 390 million (95 percent credible interval 284-528) dengue infections per year, of which 96 million (67-136) manifest apparently (any level of clinical or sub-clinical severity). This infection total is more than three times the dengue burden estimate of the World Health Organization2. Stratification of our estimates by country allows comparison with national dengue reporting, after taking into account the probability of an apparent infection being formally reported. The most notable differences are discussed. These new risk maps and infection estimates provide novel insights into the global, regional and national public health burden imposed by dengue. We anticipate that they will provide a starting point for a wider discussion about the global impact of this disease and will help guide improvements in disease control strategies using vaccine, drug and vector control methods and in their economic evaluation. [285] PMID:23563266

  16. Dengue associated choroiditis: a rare entity.

    PubMed

    Yadav, Harshali Manish; Dutta Majumder, Parthopratim; Biswas, Jyotirmay

    2017-12-01

    We report a case of choroiditis during dengue fever. A 35-year-old female presented with blurring of vision during dengue fever. Her fundus examination revealed yellow deep choroidal lesions at right macula, multiple small, yellowish subretinal macular dots along papillomacular bundle, and hyperemic disc. There was a small retinal hemorrhage at temporal margin of disc. The left eye had similar small discrete lesion superonasal and inferotemporal to macula. We report a hitherto undescribed case of choroiditis in a dengue patient.

  17. Dengue-associated acute kidney injury

    PubMed Central

    Oliveira, João Fernando Picollo; Burdmann, Emmanuel A.

    2015-01-01

    Dengue is presently the most relevant viral infection transmitted by a mosquito bite that represents a major threat to public health worldwide. Acute kidney injury (AKI) is a serious and potentially lethal complication of this disease, and the actual incidence is unknown. In this review, we will assess the most relevant epidemiological and clinical data regarding dengue and the available evidence on the frequency, etiopathogenesis, outcomes and treatment of dengue-associated AKI. PMID:26613023

  18. Dengue fever: a primer for the otolaryngologist.

    PubMed

    Arnaoutakis, Demetri; Padhya, Tapan A

    2013-07-01

    It has been estimated that more than 50 million cases of dengue occur worldwide each year, mostly in the tropics. In light of recent cases appearing in central and southern Florida, dengue has reemerged as a public health issue in the United States with respect to infection control and prevention. We review the course of dengue infection and its clinical presentation from the perspective of the practicing otolaryngologist, and we outline tactics for prevention and management.

  19. Dengue blood analysis by Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Rehman, A.; Anwar, S.; Firdous, S.; Ahmed, M.; Rasheed, R.; Nawaz, M.

    2012-06-01

    In this work Raman spectra of normal and dengue infected serum and whole blood were analyzed. In normal whole blood and serum characteristic peaks were observed when excited at 442 and 532 nm. In dengue whole blood and serum all peaks found to be blue shifted with reduced Raman intensity. Dengue whole blood and serum shows two peaks at 1614 and 1750 cm-1 which are due to presence of Immunoglobulin antibodies IgG and IgM. Whole study provides a route of information for diagnosis of dengue viral infection.

  20. Dengue Fever: Causes, Complications, and Vaccine Strategies

    PubMed Central

    Khanna, Ira

    2016-01-01

    Dengue is a highly endemic infectious disease of the tropical countries and is rapidly becoming a global burden. It is caused by any of the 4 serotypes of dengue virus and is transmitted within humans through female Aedes mosquitoes. Dengue disease varies from mild fever to severe conditions of dengue hemorrhagic fever and shock syndrome. Globalization, increased air travel, and unplanned urbanization have led to increase in the rate of infection and helped dengue to expand its geographic and demographic distribution. Dengue vaccine development has been a challenging task due to the existence of four antigenically distinct dengue virus serotypes, each capable of eliciting cross-reactive and disease-enhancing antibody response against the remaining three serotypes. Recently, Sanofi Pasteur's chimeric live-attenuated dengue vaccine candidate has been approved in Mexico, Brazil, and Philippines for usage in adults between 9 and 45 years of age. The impact of its limited application to the public health system needs to be evaluated. Simultaneously, the restricted application of this vaccine candidate warrants continued efforts in developing a dengue vaccine candidate which is additionally efficacious for infants and naïve individuals. In this context, alternative strategies of developing a designed vaccine candidate which does not allow production of enhancing antibodies should be explored, as it may expand the umbrella of efficacy to include infants and naïve individuals. PMID:27525287

  1. Human Immune Response to Dengue Infections.

    DTIC Science & Technology

    1991-06-30

    DTIC AD-A240 717 AD ____ HUMAN IMMUNE RESPONSE TO DENGUE INFECTIONS ANNUAL REPORT FRANCIS A. ENNIS JUNE 30, 1991 Supported by U.S. ARMY MEDICAL...Immune Response to Dengue Infections DAMDI7-86-C-6208 6. AUTHOR(S) 61102A 1 3M161102BS13 AA Francis A. Ennis WUDA3 12059 7. PERFORMING ORGANIZATION...of NS3, respectively. We also established 16 dengue virus-specific CD8+ CD4_ T cell clones. The clone #/2.8 recognize dengue virus types 2 and 4, and

  2. Use of Saliva for Early Dengue Diagnosis

    PubMed Central

    Ng, Lee-Ching

    2011-01-01

    Background The necessity of a venous blood collection in all dengue diagnostic assays and the high cost of tests that are available for testing during the viraemic period hinder early detection of dengue cases and thus could delay cluster management. This study reports the utility of saliva in an assay that detects dengue virus (DENV)–specific immunoglobulin A (Ig A) early in the phase of a dengue infection. Methods and Findings Using an antigen capture anti-DENV IgA (ACA) ELISA technique, we tested saliva samples collected from dengue-confirmed patients. The sensitivity within 3 days from fever onset was over 36% in primary dengue infections. The performance is markedly better in secondary infections, with 100% sensitivity reported in saliva samples from day 1 after fever onset. Serum and salivary IgA levels showed good correlation (Pearson's r = 0.69, p<0.001). Specificity was found to be 97%. Conclusion Our findings suggest that this technique would be very useful in dengue endemic regions, where the majority of dengue cases are secondary. The ACA-ELISA is easy to perform, cost effective, and especially useful in laboratories without sophisticated equipment. Our findings established the usefulness and reliability of saliva for early dengue diagnosis. PMID:21572982

  3. Dengue Fever: Causes, Complications, and Vaccine Strategies.

    PubMed

    Khetarpal, Niyati; Khanna, Ira

    2016-01-01

    Dengue is a highly endemic infectious disease of the tropical countries and is rapidly becoming a global burden. It is caused by any of the 4 serotypes of dengue virus and is transmitted within humans through female Aedes mosquitoes. Dengue disease varies from mild fever to severe conditions of dengue hemorrhagic fever and shock syndrome. Globalization, increased air travel, and unplanned urbanization have led to increase in the rate of infection and helped dengue to expand its geographic and demographic distribution. Dengue vaccine development has been a challenging task due to the existence of four antigenically distinct dengue virus serotypes, each capable of eliciting cross-reactive and disease-enhancing antibody response against the remaining three serotypes. Recently, Sanofi Pasteur's chimeric live-attenuated dengue vaccine candidate has been approved in Mexico, Brazil, and Philippines for usage in adults between 9 and 45 years of age. The impact of its limited application to the public health system needs to be evaluated. Simultaneously, the restricted application of this vaccine candidate warrants continued efforts in developing a dengue vaccine candidate which is additionally efficacious for infants and naïve individuals. In this context, alternative strategies of developing a designed vaccine candidate which does not allow production of enhancing antibodies should be explored, as it may expand the umbrella of efficacy to include infants and naïve individuals.

  4. Economic Cost of Dengue in Puerto Rico

    PubMed Central

    Halasa, Yara A.; Shepard, Donald S.; Zeng, Wu

    2012-01-01

    Dengue, endemic in Puerto Rico, reached a record high in 2010. To inform policy makers, we derived annual economic cost. We assessed direct and indirect costs of hospitalized and ambulatory dengue illness in 2010 dollars through surveillance data and interviews with 100 laboratory-confirmed dengue patients treated in 2008–2010. We corrected for underreporting by using setting-specific expansion factors. Work absenteeism because of a dengue episode exceeded the absenteeism for an episode of influenza or acute otitis media. From 2002 to 2010, the aggregate annual cost of dengue illness averaged $38.7 million, of which 70% was for adults (age 15+ years). Hospitalized patients accounted for 63% of the cost of dengue illness, and fatal cases represented an additional 17%. Households funded 48% of dengue illness cost, the government funded 24%, insurance funded 22%, and employers funded 7%. Including dengue surveillance and vector control activities, the overall annual cost of dengue was $46.45 million ($12.47 per capita). PMID:22556069

  5. Optimal Lead Time for Dengue Forecast

    PubMed Central

    Hii, Yien Ling; Rocklöv, Joacim; Wall, Stig; Ng, Lee Ching; Tang, Choon Siang; Ng, Nawi

    2012-01-01

    Background A dengue early warning system aims to prevent a dengue outbreak by providing an accurate prediction of a rise in dengue cases and sufficient time to allow timely decisions and preventive measures to be taken by local authorities. This study seeks to identify the optimal lead time for warning of dengue cases in Singapore given the duration required by a local authority to curb an outbreak. Methodology and Findings We developed a Poisson regression model to analyze relative risks of dengue cases as functions of weekly mean temperature and cumulative rainfall with lag times of 1–5 months using spline functions. We examined the duration of vector control and cluster management in dengue clusters > = 10 cases from 2000 to 2010 and used the information as an indicative window of the time required to mitigate an outbreak. Finally, we assessed the gap between forecast and successful control to determine the optimal timing for issuing an early warning in the study area. Our findings show that increasing weekly mean temperature and cumulative rainfall precede risks of increasing dengue cases by 4–20 and 8–20 weeks, respectively. These lag times provided a forecast window of 1–5 months based on the observed weather data. Based on previous vector control operations, the time needed to curb dengue outbreaks ranged from 1–3 months with a median duration of 2 months. Thus, a dengue early warning forecast given 3 months ahead of the onset of a probable epidemic would give local authorities sufficient time to mitigate an outbreak. Conclusions Optimal timing of a dengue forecast increases the functional value of an early warning system and enhances cost-effectiveness of vector control operations in response to forecasted risks. We emphasize the importance of considering the forecast-mitigation gaps in respective study areas when developing a dengue forecasting model. PMID:23110242

  6. Dengue Fever (DF) in Pakistan

    PubMed Central

    2011-01-01

    Dengue is a widespread mosquito-borne infection in human beings, which in recent years has become a major international public health concern. Symptomatic dengue virus infections can present with a wide range of clinical manifestations, from a mild febrile illness to a life-threatening shock syndrome. Both viral and host factors are thought to contribute to the manifestations of disease in each infected. It is important to understand its burden on health care, morbidity and mortality. Early diagnosis and suspicion of DF in primary care might reduce the complications if handled properly. We must understand the depth of the problem in terms of its transmission, clinical presentation, diagnosis, management and prevention. PMID:21349169

  7. Laboratory surveillance of dengue in Argentina, 1995-2001.

    PubMed

    Avilés, Gabriela; Paz, Maria Valeria; Rangeon, Griselda; Ranaivoarisoa, Marie Y; Verzeri, Nora; Roginski, Sandra; Baroni, Pablo; Enria, Delia

    2003-06-01

    Local transmission of dengue fever virus in Argentina is increased by the presence of Aedes aegypti mosquitoes and dengue outbreaks in neighboring countries. From 1995 to 2001, a laboratory-based active surveillance program detected 922 dengue cases. Indigenous transmission involving dengue-1 and -2 serotypes was confirmed only in subtropical areas in northern Argentina.

  8. Urban Epidemic of Dengue Virus Serotype 3 Infection, Senegal, 2009

    PubMed Central

    Faye, Ousmane; Ba, Yamar; Faye, Oumar; Talla, Cheikh; Diallo, Diawo; Chen, Rubing; Mondo, Mireille; Ba, Rouguiétou; Macondo, Edgard; Siby, Tidiane; Weaver, Scott C.; Diallo, Mawlouth

    2014-01-01

    An urban epidemic of dengue in Senegal during 2009 affected 196 persons and included 5 cases of dengue hemorrhagic fever and 1 fatal case of dengue shock syndrome. Dengue virus serotype 3 was identified from all patients, and Aedes aegypti mosquitoes were identified as the primary vector of the virus. PMID:24572297

  9. Urban epidemic of dengue virus serotype 3 infection, Senegal, 2009.

    PubMed

    Faye, Ousmane; Ba, Yamar; Faye, Oumar; Talla, Cheikh; Diallo, Diawo; Chen, Rubing; Mondo, Mireille; Ba, Rouguiétou; Macondo, Edgard; Siby, Tidiane; Weaver, Scott C; Diallo, Mawlouth; Sall, Amadou Alpha

    2014-03-01

    An urban epidemic of dengue in Senegal during 2009 affected 196 persons and included 5 cases of dengue hemorrhagic fever and 1 fatal case of dengue shock syndrome. Dengue virus serotype 3 was identified from all patients, and Aedes aegypti mosquitoes were identified as the primary vector of the virus.

  10. Implications of Dengue Outbreaks for Blood Supply, Australia

    PubMed Central

    Seed, Clive R.; Fryk, Jesse J.; Hyland, Catherine A.; Ritchie, Scott A.; Taylor, Carmel T.; Van Der Merwe, Kathryn L.; Flower, Robert L.P.; McBride, William J.H.

    2013-01-01

    Dengue outbreaks have increased in size and frequency in Australia, and transfusion-transmitted dengue poses a risk to transfusion safety. Using whole blood samples collected during the large 2008–2009 dengue epidemic, we estimated the risk for a dengue-infectious blood donation as ≈1 in 7,146 (range 2,218–50,021). PMID:23648012

  11. Oxidative damage in dengue fever.

    PubMed

    Seet, Raymond C S; Lee, Chung-Yung J; Lim, Erle C H; Quek, Amy M L; Yeo, Leonard L L; Huang, Shan-Hong; Halliwell, Barry

    2009-08-15

    Oxidative stress may be important in the pathogenesis of dengue infection. Using accurate markers of oxidative damage, we assessed the extent of oxidative damage in dengue patients. The levels of hydroxyeicosatetraenoic acid products (HETEs), F(2)-isoprostanes (F(2)-IsoPs), and cholesterol oxidation products (COPs) were measured in 28 adult dengue patients and 28 age-matched study controls during the febrile, defervescent, and convalescent stages of infection. We compared the absolute and the percentage change in these markers in relation to key clinical parameters and inflammatory markers. The levels of total HETEs and total HETEs/arachidonate, total F(2)-IsoPs/arachidonate, and COPs/cholesterol were higher during the febrile compared to the convalescent level. Total HETEs correlated positively with admission systolic blood pressure (r=0.52, p<0.05), whereas an inverse relationship was found between 7beta-hydroxycholesterol and systolic and diastolic blood pressure (r=-0.61 and -0.59, respectively, p<0.01). The urinary F(2)-IsoP level was higher in urine during the febrile stage compared to the convalescent level. Despite lower total cholesterol levels during the febrile stage compared to convalescent levels, a higher percentage of cholesterol was found as COPs (7beta-, 24-, and 27-hydroxycholesterol). The levels of platelet-activating factor-acetylhydrolase activity, vascular cellular adhesion molecule-1, tumor necrosis factor-alpha, and high-sensitivity C-reactive protein were higher during the febrile stage compared to their convalescent levels (p<0.01). Markers of oxidative damage are altered during the various stages of dengue infection.

  12. Recent Advances in Dengue: Relevance to Puerto Rico.

    PubMed

    Noyd, David H; Sharp, Tyler M

    2015-06-01

    Dengue represents an increasingly important public health challenge in Puerto Rico, with recent epidemics in 2007, 2010, and 2012-2013. Although recent advances in dengue vaccine development offer hope for primary prevention, the role of health professionals in the diagnosis and management of dengue patients is paramount. Case definitions for dengue, dengue with warning signs, and severe dengue provide a framework to guide clinical decision-making. Furthermore, the differentiation between dengue and other acute febrile illnesses, such as leptospirosis and chikungunya, is necessary for the appropriate diagnosis and management of cases. An understanding of dengue epidemiology and surveillance in Puerto Rico provides context for clinicians in epidemic and non-epidemic periods. This review aims to improve health professionals' ability to diagnose dengue, and as highlight the relevance of recent advances in dengue prevention and management in Puerto Rico.

  13. Recent Advances in Dengue: Relevance to Puerto Rico

    PubMed Central

    Noyd, David H.; Sharp, Tyler M.

    2015-01-01

    Dengue represents an increasingly important public health challenge in Puerto Rico, with recent epidemics in 2007, 2010, and 2012–2013. Although recent advances in dengue vaccine development offer hope for primary prevention, the role of health professionals in the diagnosis and management of dengue patients is paramount. Case definitions for dengue, dengue with warning signs, and severe dengue provide a framework to guide clinical decision-making. Furthermore, the differentiation between dengue and other acute febrile illnesses, such as leptospirosis and chikungunya, is necessary for the appropriate diagnosis and management of cases. An understanding of dengue epidemiology and surveillance in Puerto Rico provides context for clinicians in epidemic and non-epidemic periods. This review aims to improve health professionals’ ability to diagnose dengue, and as highlight the relevance of recent advances in dengue prevention and management in Puerto Rico. PMID:26061055

  14. Social justice, climate change, and dengue.

    PubMed

    Chang, Aileen Y; Fuller, Douglas O; Carrasquillo, Olveen; Beier, John C

    2014-06-14

    Climate change should be viewed fundamentally as an issue of global justice. Understanding the complex interplay of climatic and socioeconomic trends is imperative to protect human health and lessen the burden of diseases such as dengue fever. Dengue fever is rapidly expanding globally. Temperature, rainfall, and frequency of natural disasters, as well as non-climatic trends involving population growth and migration, urbanization, and international trade and travel, are expected to increase the prevalence of mosquito breeding sites, mosquito survival, the speed of mosquito reproduction, the speed of viral incubation, the distribution of dengue virus and its vectors, human migration patterns towards urban areas, and displacement after natural disasters. The burden of dengue disproportionately affects the poor due to increased environmental risk and decreased health care. Mobilization of social institutions is needed to improve the structural inequalities of poverty that predispose the poor to increased dengue fever infection and worse outcomes. This paper reviews the link between dengue and climatic factors as a starting point to developing a comprehensive understanding of how climate change affects dengue risk and how institutions can address the issues of social justice and dengue outbreaks that increasingly affect vulnerable urban populations.

  15. Dengue and Chikungunya Vector Control Pocket Guide

    USDA-ARS?s Scientific Manuscript database

    This technical guide consolidates information and procedures for surveillance and control of mosquitoes that transmit dengue and chikungunya viruses. The guide focuses on mosquitoes that transmit dengue but also makes reference to chikungunya and yellow fever because the pathogens that cause these ...

  16. Development of Dengue Infection Severity Score

    PubMed Central

    Pongpan, Surangrat; Tawichasri, Chamaiporn; Namwongprom, Sirianong

    2013-01-01

    Objectives. To develop a simple scoring system to predict dengue infection severity based on patient characteristics and routine clinical profiles. Methods. Retrospective data of children with dengue infection from 3 general hospitals in Thailand were reviewed. Dengue infection was categorized into 3 severity levels: dengue infection (DF), dengue hemorrhagic fever (DHF), and dengue shock syndrome (DSS). Coefficients of significant predictors of disease severity under ordinal regression analysis were transformed into item scores. Total scores were used to classify patients into 3 severity levels. Results. Significant clinical predictors of dengue infection severity were age >6 years, hepatomegaly, hematocrit ≥40%, systolic pressure <90 mmHg, white cell count >5000 /μL, and platelet ≤50000 /μL. The derived total scores, which ranged from 0 to 18, classified patients into 3 severity levels: DF (scores <2.5, n = 451, 58.1%), DHF (scores 2.5–11.5, n = 276, 35.5%), and DSS (scores >11.5, n = 50, 6.4%). The derived score correctly classified patients into their original severity levels in 60.7%. An under-estimation of 25.7% and an over-estimation of 13.5% were clinically acceptable. Conclusions. The derived dengue infection severity score classified patients into DF, DHF, or DSS, correctly into their original severity levels. Validation of the score should be reconfirmed before application of routine practice. PMID:24324896

  17. Hepatic Involvement in Dengue Fever in Children

    PubMed Central

    Jagadishkumar, Kalenahalli; Jain, Puja; Manjunath, Vaddambal G.; Umesh, Lingappa

    2012-01-01

    Objective Hepatic dysfunction is common in dengue infection and the degree of liver dysfunction in children varies from mild injury with elevation of transaminases to severe injury with jaundice. This study was undertaken to assess the spectrum of hepatic involvement in dengue infection. Methods 110 children with serologically positive dengue fever aged between 2 months - 14 years were studied for their hepatic functions both clinically and biochemically after excluding malaria, enteric fever, Hepatitis A and Hepatitis B with relevant investigations. Findings All cases were grouped into DF (Dengue fever), DHF (Dengue hemorrhagic fever) and DSS (Dengue shock syndrome) according to WHO criteria. The spectrum of hepatic manifestations included hepatomegaly (79%), hepatic tenderness (56%), jaundice (4.5%), raised levels of aspartate transaminase (AST)(93%), alanine transaminase (ALT)(78%), alkaline phosphatase (AP) (57%), prolonged prothrombin time (PT) (20%), reduced levels of serum albumin (66%) and abnormal abdomen ultrasound (65%). Conclusion Hepatic dysfunction was observed more in DHF and DSS group compared to DF group. About 17.27% of children had >10 fold increase in the liver enzymes. There was no correlation between the degree of hepatic enlargement or hepatic tenderness with the abnormalities of liver functions. Any child with fever, jaundice and tender hepatomegaly in geographical areas where dengue is endemic, the diagnosis of dengue infection should be strongly considered. PMID:23056891

  18. Hepatic involvement in dengue Fever in children.

    PubMed

    Jagadishkumar, Kalenahalli; Jain, Puja; Manjunath, Vaddambal G; Umesh, Lingappa

    2012-06-01

    Hepatic dysfunction is common in dengue infection and the degree of liver dysfunction in children varies from mild injury with elevation of transaminases to severe injury with jaundice. This study was undertaken to assess the spectrum of hepatic involvement in dengue infection. 110 children with serologically positive dengue fever aged between 2 months - 14 years were studied for their hepatic functions both clinically and biochemically after excluding malaria, enteric fever, Hepatitis A and Hepatitis B with relevant investigations. All cases were grouped into DF (Dengue fever), DHF (Dengue hemorrhagic fever) and DSS (Dengue shock syndrome) according to WHO criteria. The spectrum of hepatic manifestations included hepatomegaly (79%), hepatic tenderness (56%), jaundice (4.5%), raised levels of aspartate transaminase (AST)(93%), alanine transaminase (ALT)(78%), alkaline phosphatase (AP) (57%), prolonged prothrombin time (PT) (20%), reduced levels of serum albumin (66%) and abnormal abdomen ultrasound (65%). Hepatic dysfunction was observed more in DHF and DSS group compared to DF group. About 17.27% of children had >10 fold increase in the liver enzymes. There was no correlation between the degree of hepatic enlargement or hepatic tenderness with the abnormalities of liver functions. Any child with fever, jaundice and tender hepatomegaly in geographical areas where dengue is endemic, the diagnosis of dengue infection should be strongly considered.

  19. RNAi: antiviral therapy against dengue virus.

    PubMed

    Idrees, Sobia; Ashfaq, Usman A

    2013-03-01

    Dengue virus infection has become a global threat affecting around 100 countries in the world. Currently, there is no licensed antiviral agent available against dengue. Thus, there is a strong need to develop therapeutic strategies that can tackle this life threatening disease. RNA interference is an important and effective gene silencing process which degrades targeted RNA by a sequence specific process. Several studies have been conducted during the last decade to evaluate the efficiency of siRNA in inhibiting dengue virus replication. This review summarizes siRNAs as a therapeutic approach against dengue virus serotypes and concludes that siRNAs against virus and host genes can be next generation treatment of dengue virus infection.

  20. Dengue Fever, Hawaii, 2001–2002

    PubMed Central

    Pang, Lorrin; Kitsutani, Paul; Vorndam, Vance; Nakata, Michele; Ayers, Tracy; Elm, Joe; Tom, Tammy; Reiter, Paul; Rigau-Perez, José G.; Hayes, John M.; Mills, Kristin; Napier, Mike; Clark, Gary G.; Gubler, Duane J.

    2005-01-01

    Autochthonous dengue infections were last reported in Hawaii in 1944. In September 2001, the Hawaii Department of Health was notified of an unusual febrile illness in a resident with no travel history; dengue fever was confirmed. During the investigation, 1,644 persons with locally acquired denguelike illness were evaluated, and 122 (7%) laboratory-positive dengue infections were identified; dengue virus serotype 1 was isolated from 15 patients. No cases of dengue hemorrhagic fever or shock syndrome were reported. In 3 instances autochthonous infections were linked to a person who reported denguelike illness after travel to French Polynesia. Phylogenetic analyses showed the Hawaiian isolates were closely associated with contemporaneous isolates from Tahiti. Aedes albopictus was present in all communities surveyed on Oahu, Maui, Molokai, and Kauai; no Ae. aegypti were found. This outbreak underscores the importance of maintaining surveillance and control of potential disease vectors even in the absence of an imminent disease threat. PMID:15890132

  1. Dengue fever, Hawaii, 2001-2002.

    PubMed

    Effler, Paul V; Pang, Lorrin; Kitsutani, Paul; Vorndam, Vance; Nakata, Michele; Ayers, Tracy; Elm, Joe; Tom, Tammy; Reiter, Paul; Rigau-Perez, José G; Hayes, John M; Mills, Kristin; Napier, Mike; Clark, Gary G; Gubler, Duane J

    2005-05-01

    Autochthonous dengue infections were last reported in Hawaii in 1944. In September 2001, the Hawaii Department of Health was notified of an unusual febrile illness in a resident with no travel history; dengue fever was confirmed. During the investigation, 1,644 persons with locally acquired denguelike illness were evaluated, and 122 (7%) laboratory-positive dengue infections were identified; dengue virus serotype 1 was isolated from 15 patients. No cases of dengue hemorrhagic fever or shock syndrome were reported. In 3 instances autochthonous infections were linked to a person who reported denguelike illness after travel to French Polynesia. Phylogenetic analyses showed the Hawaiian isolates were closely associated with contemporaneous isolates from Tahiti. Aedes albopictus was present in all communities surveyed on Oahu, Maui, Molokai, and Kauai; no Ae. aegypti were found. This outbreak underscores the importance of maintaining surveillance and control of potential disease vectors even in the absence of an imminent disease threat.

  2. Underdiagnosis of dengue--Laredo, Texas, 1999.

    PubMed

    2001-02-02

    Dengue outbreaks have been reported in communities along the Mexico-U.S. border since 1980; however, during 1987-July 1999, no cases were reported from Laredo, Texas (1999 population: 162,000). During January-July 1999, approximately 300-325 dengue cases were reported from Nuevo Laredo, Tamaulipas, Mexico (1999 population: 274,000), a city across the Rio Grande from Laredo. To determine whether undiagnosed or unreported dengue cases had occurred in Laredo, the Texas Department of Health (TDH) reviewed medical records from five Laredo health facilities (the two city hospitals and the three largest of five community clinics). This report summarizes the findings of the review, which indicated that during July 23-August 20, 1999, 50% of suspected case-patients had undiagnosed dengue infection. Recognition of the diagnosis of dengue can be improved through heightened surveillance, professional and public education, and prompt reporting of cases by the health-care providers to local or state health departments.

  3. Dissecting Japan's Dengue Outbreak in 2014

    PubMed Central

    Quam, Mikkel B.; Sessions, October; Kamaraj, Uma Sangumathi; Rocklöv, Joacim; Wilder-Smith, Annelies

    2016-01-01

    Despite Japan's temperate climate, a dengue outbreak occurred in Tokyo for the first time in over 70 years in 2014. We dissected this dengue outbreak based on phylogenetic analysis, travel interconnectivity, and environmental drivers for dengue epidemics. Comparing the available dengue virus 1 (DENV1) E gene sequence from this outbreak with 3,282 unique DENV1 sequences in National Center for Biotechnology Information suggested that the DENV might have been imported from China, Indonesia, Singapore, or Vietnam. With travelers arriving into Japan, Guangzhou (China) may have been the source of DENV introduction, given that Guangzhou also reported a large-scale dengue outbreak in 2014. Coinciding with the 2014 outbreak, Tokyo's climate conditions permitted the amplification of Aedes vectors and the annual peak of vectorial capacity. Given suitable vectors and climate conditions in addition to increasing interconnectivity with endemic areas of Asia, Tokyo's 2014 outbreak did not come as a surprise and may foretell more to come. PMID:26711518

  4. Dengue fever: a Wikipedia clinical review.

    PubMed

    Heilman, James M; De Wolff, Jacob; Beards, Graham M; Basden, Brian J

    2014-01-01

    Dengue fever, also known as breakbone fever, is a mosquito-borne infectious tropical disease caused by the dengue virus. Symptoms include fever, headache, muscle and joint pains, and a characteristic skin rash that is similar to measles. In a small proportion of cases, the disease develops into life-threatening dengue hemorrhagic fever, which results in bleeding, thrombocytopenia, and leakage of blood plasma, or into dengue shock syndrome, in which dangerously low blood pressure occurs. Treatment of acute dengue fever is supportive, with either oral or intravenous rehydration for mild or moderate disease and use of intravenous fluids and blood transfusion for more severe cases. Along with attempts to eliminate the mosquito vector, work is ongoing to develop a vaccine and medications targeted directly at the virus.

  5. Designing a vaccination strategy against dengue.

    PubMed

    Amaku, Marcos; Coudeville, Laurent; Massad, Eduardo

    2012-10-01

    In this work we propose a mathematical approach to estimate the dengue force of infection, the average age of dengue first infection, the optimum age to vaccinate children against dengue in a routine fashion and the optimum age interval to introduce the dengue vaccine in a mass vaccination campaign. The model is based on previously published models for vaccination against other childhood infections, which resulted in actual vaccination programmes in Brazil. The model was applied for three areas of distinct levels of endemicity of the city of Recife in Northeastern State of Pernambuco, Brazil. Our results point to an optimal age to introduce the dengue vaccine in the routine immunization programme at two years of age and an age interval to introduce a mass vaccination between three and 14 years of age.

  6. [Inequities in health: the case of dengue].

    PubMed

    Vanlerberghe, Veerle; Verdonck, Kristien

    2013-01-01

    Impoverished populations carry a disproportionately high share of the burden of neglected tropical diseases, including dengue. The burden of dengue is high among poor people because they often live in communities where mosquito vectors are abundant, because they use less vector-human barrier methods, and because interventions tend to be less effective in disadvantaged populations. We believe that a better understanding and management of the "causes behind the causes" of dengue would lead to more equitable and more effective control strategies. Two main ideas are worked out. First, we propose targeted interventions in well-defined geographical areas with high risk of dengue transmission. The definition of these high-risk areas should be based on socio-economical, entomological, environmental as well as epidemiological information. Second, there is a need to adapt dengue control tools to local, context-specific factors, in active collaboration with the sectors involved in risk management as well as with the affected communities.

  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. Real-time forecasts of dengue epidemics

    NASA Astrophysics Data System (ADS)

    Yamana, T. K.; Shaman, J. L.

    2015-12-01

    Dengue is a mosquito-borne viral disease prevalent in the tropics and subtropics, with an estimated 2.5 billion people at risk of transmission. In many areas with endemic dengue, disease transmission is seasonal but prone to high inter-annual variability with occasional severe epidemics. Predicting and preparing for periods of higher than average transmission is a significant public health challenge. Here we present a model of dengue transmission and a framework for optimizing model simulations with real-time observational data of dengue cases and environmental variables in order to generate ensemble-based forecasts of the timing and severity of disease outbreaks. The model-inference system is validated using synthetic data and dengue outbreak records. Retrospective forecasts are generated for a number of locations and the accuracy of these forecasts is quantified.

  9. Governmental supervision and rapid detection on dengue vectors: An important role for dengue control in China.

    PubMed

    Guo, Yu-Hong; Lai, Sheng-jie; Liu, Xiao-Bo; Li, Gui-Chang; Yu, Hong-Jie; Liu, Qi-Yong

    2016-04-01

    China experienced an unprecedented outbreak of dengue fever in 2014, the National Health and Family Planning Commission of the People's Republic of China (NHFPC) carried out a series of supervision work on integrated vector management (IVM), and Chinese Center for Disease Control and Prevention (China CDC) conducted a rapid detection on vector density in some areas with high dengue incidence. The goal of this study was to explain the effect of these actions, which play an important role for dengue control, and we wish to give a good example for dengue control in China, even in the world. Compare mosquito vector density with Breteau Index (BI) and dengue incidence after or along with control work vs. before. Data was entered and analyzed by Microsoft Excel 2007 and SPSS19.0. Average value of BI from 22.82 in September dropped to 3.93 along with supervision and rapid detection. BI showed a significant decrease (paired sample t-test, t=3.061, P=0.018≺0.05). Dengue incidence decreased gradually along with supervision and rapid detection. Supervised work on IVM by NHFPC and the rapid detection on dengue vector Aedes by China CDC promoted to cut down the dengue vector density, then reduced dengue incidence; both played an important role for dengue control throughout China in 2014. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Vitamin D serostatus and dengue fever progression to dengue hemorrhagic fever/dengue shock syndrome.

    PubMed

    Villamor, E; Villar, L A; Lozano, A; Herrera, V M; Herrán, O F

    2017-09-14

    Vitamin D could modulate pathways leading to dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS). We examined the associations of serum total 25-hydroxy vitamin D [25(OH)D] and vitamin D binding protein (VDBP) concentrations in patients with uncomplicated dengue fever (DF) with risk of progression to DHF/DSS. In a case-control study nested in a cohort of DF patients who were followed during the acute episode in Bucaramanga, Colombia, we compared 25(OH)D and VDBP at onset of fever between 110 cases who progressed to DHF/DSS and 235 DF controls who did not progress. 25(OH)D concentrations were also compared between the acute sample and a sample collected >1 year post-convalescence in a subgroup. Compared with 25(OH)D ⩾75 nmol/l, adjusted odds ratios (95% CI) for progression were 0·44 (0·22-0·88) and 0·13 (0·02-1·05) for 50 to 75 nmol/l (vitamin D insufficiency) and <50 nmol/l (vitamin D deficiency), respectively (P, trend = 0·003). Mean 25(OH)D concentrations were much lower post-convalescence compared with the acute episode, regardless of case status. Compared with controls, mean VDBP was non-significantly lower in cases. We conclude that low serum 25(OH)D concentrations in DF patients predict decreased odds of progression to DHF/DSS.

  11. Ongoing dengue epidemic - Angola, June 2013.

    PubMed

    2013-06-21

    On April 1, 2013, the Public Health Directorate of Angola announced that six cases of dengue had been reported to the Ministry of Health of Angola (MHA). As of May 31, a total of 517 suspected dengue cases had been reported and tested for dengue with a rapid diagnostic test (RDT). A total of 313 (60.5%) specimens tested positive for dengue, including one from a patient who died. All suspected cases were reported from Luanda Province, except for two from Malanje Province. Confirmatory diagnostic testing of 49 specimens (43 RDT-positive and six RDT-negative) at the CDC Dengue Branch confirmed dengue virus (DENV) infection in 100% of the RDT-positive specimens and 50% of the RDT-negative specimens. Only DENV-1 was detected by molecular diagnostic testing. Phylogenetic analysis indicated this virus has been circulating in the region since at least 1968, strongly suggesting that dengue is endemic in Angola. Health-care professionals throughout Angola should be aware of the ongoing epidemic, the recommended practices for clinical management of dengue patients, and the need to report cases to MHA. Persons in Angola should seek medical care for acute febrile illness to reduce the risk for developing complications. Laboratory-confirmed dengue also has been reported from seven countries on four continents among persons who had recently traveled to Luanda, including 79 persons from Portugal. Angola is the third of four African countries to report a dengue outbreak in 2013. Persons returning from Africa with acute febrile illness should seek medical care, including testing for DENV infection, and suspected cases should be reported to public health authorities.

  12. Antibody-Dependent Enhancement of Dengue Virus Growth in Human Monocytes as a Risk Factor for Dengue Hemorrhagic Fever

    DTIC Science & Technology

    1989-01-01

    Clamfication) Antibody-Dependent Enhancement of Dengue Virus Growth in Human Monocytes as a Risk Factor for Dengue Hemorrhagic Fever 𔃼 PERSONAL AjTHOR(S...FELD GROUP SUBGROUP Antibody-Dependent Enhancement of Dengue Virus Growth in Human Monocytes as a Risk Factor for Dengue Hemorrhagic Fever. 19...ABSTRAC7 (Continue on reverse if necessary and identify by block number) Serum specimens~collected during a prospective study of dengue infections among

  13. Role of cognitive parameters in dengue hemorrhagic fever and dengue shock syndrome

    PubMed Central

    2013-01-01

    Dengue is becoming recognized as one of the most important vector-borne human diseases. It is predominant in tropical and subtropical zones but its geographical distribution is progressively expanding, making it an escalating global health problem of today. Dengue presents with spectrum of clinical manifestations, ranging from asymptomatic, undifferentiated mild fever, dengue fever (DF), to dengue hemorrhagic fever (DHF) with or without shock (DSS), a life-threatening illness characterized by plasma leakage due to increased vascular permeability. Currently, there are no antiviral modalities or vaccines available to treat and prevent dengue. Supportive care with close monitoring is the standard clinical practice. The mechanisms leading to DHF/DSS remains poorly understood. Multiple factors have been attributed to the pathological mechanism, but only a couple of these hypotheses are popular in scientific circles. The current discussion focuses on underappreciated factors, temperature, natural IgM, and endotoxin, which may be critical components playing roles in dengue pathogenesis. PMID:24305068

  14. A recombinant, chimeric tetravalent dengue vaccine candidate based on a dengue virus serotype 2 backbone.

    PubMed

    Osorio, Jorge E; Wallace, Derek; Stinchcomb, Dan T

    2016-01-01

    Dengue fever is caused by infection with one of four dengue virus (DENV) serotypes (DENV-1-4), necessitating tetravalent dengue vaccines that can induce protection against all four DENV. Takeda's live attenuated tetravalent dengue vaccine candidate (TDV) comprises an attenuated DENV-2 strain plus chimeric viruses containing the prM and E genes of DENV-1, -3 and -4 cloned into the attenuated DENV-2 'backbone'. In Phase 1 and 2 studies, TDV was well tolerated by children and adults aged 1.5-45 years, irrespective of prior dengue exposure; mild injection-site symptoms were the most common adverse events. TDV induced neutralizing antibody responses and seroconversion to all four DENV as well as cross-reactive T cell-mediated responses that may be necessary for broad protection against dengue fever.

  15. DengueTools: innovative tools and strategies for the surveillance and control of dengue

    PubMed Central

    Wilder-Smith, Annelies; Renhorn, Karl-Erik; Tissera, Hasitha; Abu Bakar, Sazaly; Alphey, Luke; Kittayapong, Pattamaporn; Lindsay, Steve; Logan, James; Hatz, Christoph; Reiter, Paul; Rocklöv, Joacim; Byass, Peter; Louis, Valérie R.; Tozan, Yesim; Massad, Eduardo; Tenorio, Antonio; Lagneau, Christophe; L'Ambert, Grégory; Brooks, David; Wegerdt, Johannah; Gubler, Duane

    2012-01-01

    Dengue fever is a mosquito-borne viral disease estimated to cause about 230 million infections worldwide every year, of which 25,000 are fatal. Global incidence has risen rapidly in recent decades with some 3.6 billion people, over half of the world's population, now at risk, mainly in urban centres of the tropics and subtropics. Demographic and societal changes, in particular urbanization, globalization, and increased international travel, are major contributors to the rise in incidence and geographic expansion of dengue infections. Major research gaps continue to hamper the control of dengue. The European Commission launched a call under the 7th Framework Programme with the title of ‘Comprehensive control of Dengue fever under changing climatic conditions’. Fourteen partners from several countries in Europe, Asia, and South America formed a consortium named ‘DengueTools’ to respond to the call to achieve better diagnosis, surveillance, prevention, and predictive models and improve our understanding of the spread of dengue to previously uninfected regions (including Europe) in the context of globalization and climate change. The consortium comprises 12 work packages to address a set of research questions in three areas: Research area 1: Develop a comprehensive early warning and surveillance system that has predictive capability for epidemic dengue and benefits from novel tools for laboratory diagnosis and vector monitoring. Research area 2: Develop novel strategies to prevent dengue in children. Research area 3: Understand and predict the risk of global spread of dengue, in particular the risk of introduction and establishment in Europe, within the context of parameters of vectorial capacity, global mobility, and climate change. In this paper, we report on the rationale and specific study objectives of ‘DengueTools’. DengueTools is funded under the Health theme of the Seventh Framework Programme of the European Community, Grant Agreement Number: 282589

  16. Vaccines and immunization strategies for dengue prevention

    PubMed Central

    Liu, Yang; Liu, Jianying; Cheng, Gong

    2016-01-01

    Dengue is currently the most significant arboviral disease afflicting tropical and sub-tropical countries worldwide. Dengue vaccines, such as the multivalent attenuated, chimeric, DNA and inactivated vaccines, have been developed to prevent dengue infection in humans, and they function predominantly by stimulating immune responses against the dengue virus (DENV) envelope (E) and nonstructural-1 proteins (NS1). Of these vaccines, a live attenuated chimeric tetravalent DENV vaccine developed by Sanofi Pasteur has been licensed in several countries. However, this vaccine renders only partial protection against the DENV2 infection and is associated with an unexplained increased incidence of hospitalization for severe dengue disease among children younger than nine years old. In addition to the virus-based vaccines, several mosquito-based dengue immunization strategies have been developed to interrupt the vector competence and effectively reduce the number of infected mosquito vectors, thus controlling the transmission of DENV in nature. Here we summarize the recent progress in the development of dengue vaccines and novel immunization strategies and propose some prospective vaccine strategies for disease prevention in the future. PMID:27436365

  17. Vaccines and immunization strategies for dengue prevention.

    PubMed

    Liu, Yang; Liu, Jianying; Cheng, Gong

    2016-07-20

    Dengue is currently the most significant arboviral disease afflicting tropical and sub-tropical countries worldwide. Dengue vaccines, such as the multivalent attenuated, chimeric, DNA and inactivated vaccines, have been developed to prevent dengue infection in humans, and they function predominantly by stimulating immune responses against the dengue virus (DENV) envelope (E) and nonstructural-1 proteins (NS1). Of these vaccines, a live attenuated chimeric tetravalent DENV vaccine developed by Sanofi Pasteur has been licensed in several countries. However, this vaccine renders only partial protection against the DENV2 infection and is associated with an unexplained increased incidence of hospitalization for severe dengue disease among children younger than nine years old. In addition to the virus-based vaccines, several mosquito-based dengue immunization strategies have been developed to interrupt the vector competence and effectively reduce the number of infected mosquito vectors, thus controlling the transmission of DENV in nature. Here we summarize the recent progress in the development of dengue vaccines and novel immunization strategies and propose some prospective vaccine strategies for disease prevention in the future.

  18. Current issues in the economics of vaccination against dengue.

    PubMed

    Tozan, Yesim

    2016-01-01

    Dengue is a major public health concern in tropical and subtropical areas of the world. The prospects for dengue prevention have recently improved with the results of efficacy trials of a tetravalent dengue vaccine. Although partially effective, once licensed, its introduction can be a public health priority in heavily affected countries because of the perceived public health importance of dengue. This review explores the most immediate economic considerations of introducing a new dengue vaccine and evaluates the published economic analyses of dengue vaccination. Findings indicate that the current economic evidence base is of limited utility to support country-level decisions on dengue vaccine introduction. There are a handful of published cost-effectiveness studies and no country-specific costing studies to project the full resource requirements of dengue vaccine introduction. Country-level analytical expertise in economic analyses, another gap identified, needs to be strengthened to facilitate evidence-based decision-making on dengue vaccine introduction in endemic countries.

  19. Safety Testing of Dengue-2 and Dengue-4 Viruses for Use in Human Challenge Experiments

    DTIC Science & Technology

    1988-04-01

    16.6 IIJI 2 N ,RSLIO JS ’, %AN -T N ," 1 0 % :.i. AD Ln MC.tILE (UiO Safety Testinq of Dengue -2 and Denque-4 Viruses for Use in Human Chal, nqe...ELEMENT NO. NO. 3M16 NO. ACCESSION NO. 62770A 2770A871 AA 110 11. TITLE (Include Security Classification) Safety Testing of Dengue -2 and Dengue -4 Viruses...if necessary and identify by block number) FIELD GROUP SUB-GROUP Dengue Fever, Viruses, Mice, Rabbits, Guinea Pig, 06 13 Tropical Medicine, Virology

  20. Non-hemorrhagic dengue fever with rhabdomyolysis.

    PubMed

    Jha, Ratan; Gude, Dilip; Chennamsetty, Sashidhar

    2013-11-01

    Acute kidney injury occurs in 33-50% of patients with rhabdomyolysis and infections remain one of the major contributing factors. The incidence of rhabdomyolysis in non-hemorrhagic dengue virus infection is quite low and may go unnoticed, especially if the presentation is not florid. We report a case of a young male patient, sero-positive for dengue, with no hemorrhagic manifestations or hypotension, who developed rhabdomyolysis complicated by renal failure. The patient eventually needed dialysis support and later recovered fully. Clinicians need to be aware of the occurrence of rhabdomyolysis even in patients without the hemorrhagic manifestations of dengue viral infection and should employ early preventive strategies in such cases.

  1. Anterior ischemic optic neuropathy following dengue fever

    PubMed Central

    Ramakrishnan, Reshma; Shrivastava, Saurabh; Deshpande, Shrikant; Patkar, Priyanka

    2016-01-01

    Dengue fever is caused by a flavivirus. This infection is endemic in the tropics and warm temperate regions of the world. Ocular manifestations of dengue fever include subconjunctival, vitreous, and retinal haemorrhages; posterior uveitis; optic neuritis; and maculopathies, haemorrhage, and oedema. However anterior ischemic optic neuropathy is a rare presentation. Optic nerve ischemia most frequently occurs at the optic nerve head, where structural crowding of nerve fibers and reduction of the vascular supply may combine to impair perfusion to a critical degree and produce optic disc oedema. Here we present a case of anterior ischemic optic neurapathy associated with dengue fever. PMID:27843231

  2. Anterior ischemic optic neuropathy following dengue fever.

    PubMed

    Ramakrishnan, Reshma; Shrivastava, Saurabh; Deshpande, Shrikant; Patkar, Priyanka

    2016-01-01

    Dengue fever is caused by a flavivirus. This infection is endemic in the tropics and warm temperate regions of the world. Ocular manifestations of dengue fever include subconjunctival, vitreous, and retinal haemorrhages; posterior uveitis; optic neuritis; and maculopathies, haemorrhage, and oedema. However anterior ischemic optic neuropathy is a rare presentation. Optic nerve ischemia most frequently occurs at the optic nerve head, where structural crowding of nerve fibers and reduction of the vascular supply may combine to impair perfusion to a critical degree and produce optic disc oedema. Here we present a case of anterior ischemic optic neurapathy associated with dengue fever.

  3. Human Immune Responses to Dengue Viruses.

    DTIC Science & Technology

    1984-08-01

    ND-R171 381 HUR IMMUNE RESPONSES TO DENGUE VIRUSES(U) 1/1 MASSRCHUSETTS UNIY M9DICAL SCHOOL WORCESTER F R~ ENNIS RUG 94 DRMt17-2-C-2233 UNCLASSIFIED...Responses to Dengue Viruses Annual Report 0(August 1983-July 1984) Francis A. Ennis, M.D. August 1984 Supported by U.S. Army Medical Research and...3M1- NO. SON No. Frederick, Maryland 21701-5012 61102A 61102BSI0 AA 104 11. TITLE Oxkf* Samqy Oao" Human Immune Responses to Dengue Viruses 12. PERSON

  4. Pathogenesis of Dengue Vaccine Viruses in Mosquitoes.

    DTIC Science & Technology

    1981-01-01

    AD-AI30 52S PATHOGENESIS OF DENGUE VACCINE VIRUSES IN MOSQUITOES i/I (U) VALE UNIV NEW HAVEN CONN SCHOOL OF MEDICINE B J BEATY ET AL. 81 JAN 81 DAMDi...UNCLASSIFIED PATHOGENESIS OF DENGUE VACCINE VIRUSES IN MOSQUITOES Second Annual Report Barry J. Beaty, Ph.D. D T IC ; Thomas H.G. Aitken, Ph.D...REPORT NUMBER 2. GOVT ACCESSION NO. 3. RECIPIENT’S CATALOG NUMBER 4. TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVERED PATHOMMSIS CF DENGUE

  5. Human Immune Responses to Dengue Viruses.

    DTIC Science & Technology

    1983-09-01

    A-Al?l 362 HUMAN IMMUNE RESPONSES TO DENGUE YXRUSES(U) MASSACHUSETTS UNIV MEDICAL SCHOOL NORCESTER F A ENNIS SE 83" I ?-2C23 UNCLASSI FIED SE 3IRD?8...SHEET PREVIOUS EDITION MAY BE USED UNTILDTIC FORM 70A OUMNPRESIGSETSTOCK IS EXHAUSTED.DEC 83 AD IHuman Immune Responses to Dengue Viruses Annual Report...edilon may be ued Y01dxffnUICFMCASIAZIlow f~ rolit SUMMARY The purpose of this contract is to analyse the immune responses to dengue virus infections

  6. Human Immune Responses to Dengue Viruses.

    DTIC Science & Technology

    1986-07-01

    AD-AISI 652 NUMAN IMMUNE RESPONSES TO DENGUE YIRUSES(U) / MASSACHUSETTS UNJY MEDICAL CENTER WORCESTER "A F A ENNIS 61 JUL 86 DRMDI?-82-C-2233...A S. PAGE COUNT Ie ..U rO l-9SJulyl (vw = T 21 Virus; Dengue ; Arbovirus; Immunology -- 4b he,. SAaaY~d the Interaction between the peripheral blood...lymphocytes (PBL) of non- 10m.0 deors ad dengue virus-Infected cells, which results in Interferon (113) production. AutelepMu mecyts@ or the Zpstein

  7. Human Immune Responses to Dengue Viruses.

    DTIC Science & Technology

    1986-08-01

    D-Ai8i 71S UMAN IMMUNE RESPONSES TO DENGUE VIRUSES(U) MASSACHUSETTS UNIV M DICAL CENTER WORCESTER MA F A ENNIS 81 AUG 86 DAD17-82-C-2233 UNCLSE...Classification) (U) Human Immune Responses to Dengue Viruses 12. PERSONAL AUTHOR(S) Ennis. Francis A. 13a. TYPE OF REPORT 13b. TIME COVERED 414. DATE OF...Continue on reverse if necessary and identify by block number) FIELD GROUP SUB-GROUP06 13 Virus; Dengue ; Arbovirus; Immunology 06 03 I9% ABSTRACT

  8. Development of Dengue Vaccine, Phase 1

    DTIC Science & Technology

    1987-07-01

    AD-A260 281 AD____ CONTRACT NO: DAMD17-87-C-7061 D TIC([%ELECTE TITLE: DEVELOPMENT OF DENGUE VACCINE, PHASE I S 6 PRINCIPAL INVESTIGATOR: John M. Ivy...Phase I (12/15/86-6/15/871 J- " , : T.5 5 JNDOZG :;UMBERS Contract No. Development of Dengue Vaccine, Phase I DAMD17-87-C-7061 65502A 13P665502M802.AA...distribution unlimited Dengue virus is a mosquito borne, positive strand RNA virus responsi- ble for hundreds of thousands of illnesses annually. No

  9. Human Immune Responses to Dengue Viruses.

    DTIC Science & Technology

    1985-08-01

    t-Ril 630 HuMAN IMMUNE RESPONSES TO DENGUE VIRUSES(U) 1 - MASSACHUSETTS UNIV MEDICAL SCHOOL WORCESTER F A ENNIS 01 AUGO 95 DAMDI-2-C-2233 UNCASSIFIED...Classification) (U) Human Immune Responses to Dengue Viruses 12. PERSONAL AUTHOR(S) Ennis, Francis A. 13a. TYPE OF REPORT 13b. TIME COVERED 14. DATE OF...on reverse if necessary and identify by block number) FIELD GROUP SUB-GROUP06 13 Virus; Dengue ; Arbovirus; Immunology 06 13 19. ABSTRACT (Continue on

  10. Human Immune Response to Dengue Infections.

    DTIC Science & Technology

    1987-07-30

    W5l "I± H"MN IMMUNE RESPONSE TO DENGUE INFECTIONS(U) i/il MASSACHUSETTS UNIV MEDICAL CENTER NORCESTER MR1 F R ENIS 36 JUL 87 DAMD7-86-C-6200...1 U . AD HUMAN IMMUNE RESPONSE TO DENGUE INFECTIONS ANNUAL REPORT In 00 FRANCIS A. ENNIS JULY 30, 1987 Supported by U.S. ARMY MEDICAL RESEARCH...Human Immune Response to Dengue Infections 12. PERSONAL AUTHOR(S) Ennis, Francis A. 13a. TYPE OF REPORT 13b. TIME COVERED 14. DATE OF REPORT (Year

  11. Pathogenesis of Dengue Vaccine Viruses in Mosquitoes.

    DTIC Science & Technology

    1982-01-01

    AD-R38 519 PATHOGENESIS OF DENGUE VACCINE VIRUSES IN MOSQUITOES i/i (U) YALE UNIV NEW HAVEN CONN SCHOOL OF MEDICINE B J BEATY ET AL. 81 JAN 82 DAMDI...NATIONAL BUREAU OF STANDARDS 1963-A i UNCLASSIFIED ":’:" AD 2 0. PATHOGENESIS OF DENGUE VACCINE VIRUSES IN MOSQUITOES Third Annual Report Barry J. Beaty...SUPPLEMENTARY NOTES 1 7 Y NORDS (rontinue on reverq , side if necessary and identify by hlock numb-) Dengue -2 S-1 vaccine, PR-159 parent; IDenque-1

  12. Temperature dependent conformational change of dengue virus.

    PubMed

    Zhang, Xinzheng; Sun, Lei; Rossmann, Michael G

    2015-06-01

    Dengue virus is the causative agent of dengue virus fever. It infects about 400 million people per year and leads to about 21,000 deaths annually. There is available neither a fully successful vaccine nor a successful drug therapy. Some dengue virus serotypes undergo a temperature dependent conformational change from a 'smooth' form at lower temperatures to a 'bumpy' form at temperatures approaching 37°C, the human body temperature. The bumpy structure is less stable and is probably an intermediate in the formation of a fusogenic virus particle. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. [Neonatal dengue in Peru: a case report].

    PubMed

    Silva Delgado, Hermann; Ruiz Ríos, Juan Carlo; Vela Barbarán, Erick Leray; Rengifo Del Aguila, Deicy; García M, María; Rodríguez Benavides, Luis; Mendoza-Ticona, Alberto

    2011-03-01

    We present the case of a full-term female newborn, whose mother died seven days postpartum from multi-organ failure due to severe dengue confirmed by NS1 antigen detection and positive IgM. The newborn did not have any complication, but at the fourth day of life she developed fever, jaundice, signs of plasma leakage, thrombocytopenia, hepatomegaly, ascitis, and others signs of systemic inflammation response syndrome. She fully recovered with supportive treatment. The RT-PCR test of a peripheral blood sample revealed a positive result for the dengue virus serotype 2, confirming the first case of neonatal dengue reported in Peru.

  14. The use of rapid dengue diagnostic tests in a routine clinical setting in a dengue-endemic area of Colombia

    PubMed Central

    Osorio, Lyda; Uribe, Marcela; Ardila, Gloria Ines; Orejuela, Yaneth; Velasco, Margarita; Bonelo, Anilza; Parra, Beatriz

    2015-01-01

    There is insufficient evidence of the usefulness of dengue diagnostic tests under routine conditions. We sought to analyse how physicians are using dengue diagnostics to inform research and development. Subjects attending 14 health institutions in an endemic area of Colombia with either a clinical diagnosis of dengue or for whom a dengue test was ordered were included in the study. Patterns of test-use are described herein. Factors associated with the ordering of dengue diagnostic tests were identified using contingency tables, nonparametric tests and logistic regression. A total of 778 subjects were diagnosed with dengue by the treating physician, of whom 386 (49.5%) were tested for dengue. Another 491 dengue tests were ordered in subjects whose primary diagnosis was not dengue. Severe dengue classification [odds ratio (OR) 2.2; 95% confidence interval (CI) 1.1-4.5], emergency consultation (OR 1.9; 95% CI 1.4-2.5) and month of the year (OR 3.1; 95% CI 1.7-5.5) were independently associated with ordering of dengue tests. Dengue tests were used both to rule in and rule out diagnosis. The latter use is not justified by the sensitivity of current rapid dengue diagnostic tests. Ordering of dengue tests appear to depend on a combination of factors, including physician and institutional preferences, as well as other patient and epidemiological factors. PMID:25993399

  15. The use of rapid dengue diagnostic tests in a routine clinical setting in a dengue-endemic area of Colombia.

    PubMed

    Osorio, Lyda; Uribe, Marcela; Ardila, Gloria Ines; Orejuela, Yaneth; Velasco, Margarita; Bonelo, Anilza; Parra, Beatriz

    2015-06-01

    There is insufficient evidence of the usefulness of dengue diagnostic tests under routine conditions. We sought to analyse how physicians are using dengue diagnostics to inform research and development. Subjects attending 14 health institutions in an endemic area of Colombia with either a clinical diagnosis of dengue or for whom a dengue test was ordered were included in the study. Patterns of test-use are described herein. Factors associated with the ordering of dengue diagnostic tests were identified using contingency tables, nonparametric tests and logistic regression. A total of 778 subjects were diagnosed with dengue by the treating physician, of whom 386 (49.5%) were tested for dengue. Another 491 dengue tests were ordered in subjects whose primary diagnosis was not dengue. Severe dengue classification [odds ratio (OR) 2.2; 95% confidence interval (CI) 1.1-4.5], emergency consultation (OR 1.9; 95% CI 1.4-2.5) and month of the year (OR 3.1; 95% CI 1.7-5.5) were independently associated with ordering of dengue tests. Dengue tests were used both to rule in and rule out diagnosis. The latter use is not justified by the sensitivity of current rapid dengue diagnostic tests. Ordering of dengue tests appear to depend on a combination of factors, including physician and institutional preferences, as well as other patient and epidemiological factors.

  16. Dengue Expansion in Africa—Not Recognized or Not Happening?

    PubMed Central

    Junghanss, Thomas; Wills, Bridget; Brady, Oliver J.; Eckerle, Isabella; Farlow, Andrew; Hay, Simon I.; McCall, Philip J.; Messina, Jane P.; Ofula, Victor; Sall, Amadou A.; Sakuntabhai, Anavaj; Velayudhan, Raman; Wint, G.R. William; Zeller, Herve; Margolis, Harold S.; Sankoh, Osman

    2014-01-01

    An expert conference on Dengue in Africa was held in Accra, Ghana, in February 2013 to consider key questions regarding the possible expansion of dengue in Africa. Four key action points were highlighted to advance our understanding of the epidemiology of dengue in Africa. First, dengue diagnostic tools must be made more widely available in the healthcare setting in Africa. Second, representative data need to be collected across Africa to uncover the true burden of dengue. Third, established networks should collaborate to produce these types of data. Fourth, policy needs to be informed so the necessary steps can be taken to provide dengue vector control and health services. PMID:25271370

  17. Dengue expansion in Africa-not recognized or not happening?

    PubMed

    Jaenisch, Thomas; Junghanss, Thomas; Wills, Bridget; Brady, Oliver J; Eckerle, Isabella; Farlow, Andrew; Hay, Simon I; McCall, Philip J; Messina, Jane P; Ofula, Victor; Sall, Amadou A; Sakuntabhai, Anavaj; Velayudhan, Raman; Wint, G R William; Zeller, Herve; Margolis, Harold S; Sankoh, Osman

    2014-10-01

    An expert conference on Dengue in Africa was held in Accra, Ghana, in February 2013 to consider key questions regarding the possible expansion of dengue in Africa. Four key action points were highlighted to advance our understanding of the epidemiology of dengue in Africa. First, dengue diagnostic tools must be made more widely available in the healthcare setting in Africa. Second, representative data need to be collected across Africa to uncover the true burden of dengue. Third, established networks should collaborate to produce these types of data. Fourth, policy needs to be informed so the necessary steps can be taken to provide dengue vector control and health services.

  18. First documented outbreak of dengue in the Peruvian Amazon region.

    PubMed

    Phillips, I; Need, J; Escamilla, J; Colán, E; Sánchez, S; Rodríguez, M; Vásquez, L; Seminario, J; Betz, T; da Rosa, A T

    1992-01-01

    This article describes a classical dengue outbreak caused by dengue serotypes 1 and 4 that occurred from March to July 1990 in the city of Iquitos and surrounding areas of Loreto Department in the Peruvian Amazon. Epidemiologic data indicate that more than 150,000 persons may have been affected in Iquitos alone. Another dengue outbreak occurred in Tarapoto, a city in the neighboring department of San Martín. Laboratory data indicate that the same dengue serotypes were involved in both outbreaks. No cases of dengue hemorrhagic fever/shock syndrome appear to have occurred. Prior to this outbreak, no indigenous dengue cases had been documented in Peru.

  19. Unusual Presentation of Dengue Fever Leading to Unnecessary Appendectomy

    PubMed Central

    Kumar, Lovekesh; Singh, Mahendra; Saxena, Ashish; Kolhe, Yuvraj; Karande, Snehal K.; Singh, Narendra; Venkatesh, P.; Meena, Rambabu

    2015-01-01

    Dengue fever is the most important arbovirus illness with an estimated incidence of 50–100 million cases per year. The common symptoms of dengue include fever, rash, malaise, nausea, vomiting, and musculoskeletal pain. Dengue fever may present as acute abdomen leading to diagnostic dilemma. The acute surgical complications of dengue fever include acute pancreatitis, acute acalculous cholecystitis, nonspecific peritonitis, and acute appendicitis. We report a case of dengue fever that mimicked acute appendicitis leading to unnecessary appendectomy. A careful history examination for dengue-related signs, and serial hemogram over the first 3-4 days of disease may prevent unnecessary appendectomy. PMID:26167314

  20. Unusual Presentation of Dengue Fever Leading to Unnecessary Appendectomy.

    PubMed

    Kumar, Lovekesh; Singh, Mahendra; Saxena, Ashish; Kolhe, Yuvraj; Karande, Snehal K; Singh, Narendra; Venkatesh, P; Meena, Rambabu

    2015-01-01

    Dengue fever is the most important arbovirus illness with an estimated incidence of 50-100 million cases per year. The common symptoms of dengue include fever, rash, malaise, nausea, vomiting, and musculoskeletal pain. Dengue fever may present as acute abdomen leading to diagnostic dilemma. The acute surgical complications of dengue fever include acute pancreatitis, acute acalculous cholecystitis, nonspecific peritonitis, and acute appendicitis. We report a case of dengue fever that mimicked acute appendicitis leading to unnecessary appendectomy. A careful history examination for dengue-related signs, and serial hemogram over the first 3-4 days of disease may prevent unnecessary appendectomy.

  1. Dengue virus in Mexican bats

    PubMed Central

    AGUILAR-SETIÉN, Á.; ROMERO-ALMARAZ, M. L.; SÁNCHEZ-HERNÁNDEZ, C.; FIGUEROA, R.; JUÁREZ-PALMA, L. P.; GARCÍA-FLORES, M. M.; VÁZQUEZ-SALINAS, C.; SALAS-ROJAS, M.; HIDALGO-MARTÍNEZ, A. C.; PIERLÉ, S. AGUILAR; GARCÍA-ESTRADA, C.; RAMOS, C.

    2008-01-01

    SUMMARY Individuals belonging to five families, 12 genera, and 19 different species of bats from dengue endemic areas in the Gulf and Pacific coasts of Mexico were examined by ELISA, RT–PCR, and for the presence of dengue virus (DV) NS1 protein. Nine individuals from four species were seropositive by ELISA: three insectivorous, Myotis nigricans (four positives/12 examined), Pteronotus parnellii (3/19), and Natalus stramineus (1/4), and one frugivorous Artibeus jamaicensis (1/35) (12·86% seroprevalence in positive species). DV serotype 2 was detected by RT–PCR in four samples from three species (all from the Gulf coast – rainy season): two frugivorous, A. jamaicensis (2/9), and Carollia brevicauda (1/2), and one insectivorous, M. nigricans (1/11). The latter was simultaneously positive for NS1 protein. DV RT–PCR positive animals were all antibody seronegative. M. nigricans showed positive individuals for all three tests. This is the first evidence suggesting the presence of DV in bats from Mexico. PMID:18325131

  2. Dengue: an update on treatment options.

    PubMed

    Chan, Candice Y Y; Ooi, Eng Eong

    2015-01-01

    Dengue is the most important mosquito-borne viral pathogen globally, with approximately 100 million cases of acute dengue annually. Infection can result in severe, life-threatening disease. Currently, there is no effective vaccine or licensed antiviral. Management is primarily supportive with fluids. Direct antiviral therapies that reduce dengue severity could be useful although these would need to inhibit all four viral serotypes effectively. This review focuses on the interventions that currently considered the gold standard in case management as well as exploratory therapies that have been studied in clinical trials. Although antiviral drug and therapeutic antibodies for dengue remain a work in progress, these studies have produced some promising results and may have the potential to be future drugs.

  3. Case Management of Dengue: Lessons Learned.

    PubMed

    Kalayanarooj, Siripen; Rothman, Alan L; Srikiatkhachorn, Anon

    2017-03-01

    The global burden of dengue and its geographic distribution have increased over the past several decades. The introduction of dengue in new areas has often been accompanied by high case-fatality rates. Drawing on the experience in managing dengue cases at the Queen Sirikit National Institute of Child Health in Bangkok, Thailand, this article provides the authors' perspectives on key clinical lessons to improve dengue-related outcomes. Parallels between this clinical experience and outcomes reported in randomized controlled trials, results of efforts to disseminate practice recommendations, and suggestions for areas for further research are also discussed. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

  4. Safety Testing of Dengue-1 and Dengue-3 Seeds for Human Challenges, Unattenuated; Hepatitis A Virus, Strain HM-175

    DTIC Science & Technology

    1989-06-01

    q j. AD 00 CSAFETY TESTING OF DENGUE -1 AND DENGUE -3 SEEDS FOR HUMAN CHALLENGES, UNATTENUATED; 0HEPATITIS A VIRUS, STRAIN HM-1750 FINAL REPORT By D...TITLE (Include Scurrty Classifcation)627A 27A8JC09 (U) Safety Testing of Dengue -1 and Dengue -3 Seeds for Human Challenges, Unattenuatei; Hepatitis A...necenary and identify by block number) 06EL GR3U Dengue -1; Dengue -3; Hepatitis A; Viral seeds; Vaccine; PA-1 06 03 I 1 ABSTRACT (Continue On reverse it

  5. Safety Testing of Dengue-1 and Dengue-3 Seeds for Human Challenges, Unattenuated; Hepatitis A Virus, Strain HM175

    DTIC Science & Technology

    1988-07-01

    AD SAFETY TESTING OF DENGUE -I AND DENGUE -3 SEEDS FOR HUMAN CHALLENGES, UNATrENUATED; HEPATITIS A VIRUS, STRAIN HM175 PHASE REPOR DTICcUUS PO.CASH{ I... Dengue -1 and Dengue -3 Seeds for Human Challenges, Unattenuated; Hepatitis A Virus. -Strain HM175 12. PERSONAL AUThOR(S) Potash, Louis 13&. TYPE OF...COSATI CODES ? B. SUBJECT TERMS (C~in0iU* an LIve i ec*ty arid identify by bdocir nunme) FIELD GROUP SU-GROUP 06 13 L Dengue -1; Dengue -3; Hepatitis A

  6. Association of interleukin-2, -4 and -10 with dengue severity.

    PubMed

    Abhishek, Kumar S; Chakravarti, Anita; Baveja, C P; Kumar, Naresh; Siddiqui, Oves; Kumar, Suman

    2017-01-01

    Dengue is an arboviral disease caused by four distinct serotypes of dengue virus. The pathogenesis of dengue is not very clearly understood. Various pro- and anti-inflammatory cytokines are involved in the immune pathogenesis of dengue. Interleukin (IL)-2/IL-2 receptor interaction is supposed to play a protective role, while IL-4 acts as pro-inflammatory whereas IL-10 acts as anti-inflammatory cytokines. So far, not much information is available regarding the established role of these cytokines with dengue infection and severity. our study aimed to show the association of IL-2, -4, and -10 with severity of dengue infection. This was a cross-sectional study. The study was conducted in the year 2015; 150 blood samples from suspected dengue cases were confirmed for dengue and then with an equal number of healthy control samples were tested for cytokines levels (IL-2, -4, and -10) by ELISA. Severity of the dengue infection was determined on the basis of clinical manifestations based on the WHO criteria. for statistical analysis, SPSS version 21 (IBM, New York, United States) was used. Out of 150 samples, 56 samples came to be dengue positive. Thirty-eight (67.85%) cases were classified as nonsevere dengue and 18 (32.15%) were severe dengue. The serum levels of IL-4 and -10 were significantly raised in severe dengue cases as compared to nonsevere dengue cases. No significant association was observed between serum IL-2 levels and the severity of dengue. IL-4 and -10 levels can be used as marker of severe dengue and help in early preparedness to start the treatment in the line of severe dengue.

  7. Lung in Dengue: Computed Tomography Findings

    PubMed Central

    Rodrigues, Rosana Souza; Brum, Ana Livia Garcia; Paes, Marciano Viana; Póvoa, Tiago Fajardo; Basilio-de-Oliveira, Carlos Alberto; Marchiori, Edson; Borghi, Danielle Provençano; Ramos, Grazielle Viana; Bozza, Fernando Augusto

    2014-01-01

    Background Dengue is the most important mosquito-borne viral disease in the world. Dengue virus infection may be asymptomatic or lead to undifferentiated fever, dengue fever with or without warning signs, or severe dengue. Lower respiratory symptoms are unusual and lung-imaging data in patients with dengue are scarce. Methodology/Principal Findings To evaluate lung changes associated with dengue infection, we retrospectively analyzed 2,020 confirmed cases of dengue. Twenty-nine of these patients (11 females and 18 males aged 16–90 years) underwent chest computed tomography (CT), which yielded abnormal findings in 17 patients: 16 patients had pleural effusion (the sole finding in six patients) and 11 patients had pulmonary abnormalities. Lung parenchyma involvement ranged from subtle to moderate unilateral and bilateral abnormalities. The most common finding was ground-glass opacity in eight patients, followed by consolidation in six patients. Less common findings were airspace nodules (two patients), interlobular septal thickening (two patients), and peribronchovascular interstitial thickening (one patient). Lung histopathological findings in four fatal cases showed thickening of the alveolar septa, hemorrhage, and interstitial edema. Conclusions/Significance In this largest series involving the use of chest CT to evaluate lung involvement in patients with dengue, CT findings of lower respiratory tract involvement were uncommon. When abnormalities were present, pleural effusion was the most frequent finding and lung involvement was often mild or moderate and bilateral. Extensive lung abnormalities are infrequent even in severe disease and when present should lead physicians to consider other diagnostic possibilities. PMID:24836605

  8. Pathogenesis of Dengue Vaccine Viruses in Mosquitoes.

    DTIC Science & Technology

    1980-01-01

    1973). Sabin (1948) showed that attenuated dpngiie, passed through mosquitoes, did not revert to pathogenicity frnr man. -7- Thus even if the vaccine ...AD-A138 518 PATHOGENESIS OF DENGUE VACCINE YIRUSES IN MOSQUITOES 1/ (U) YALE UNIV NEW HAVEN CONN SCHOOL OF MEDICINE B J BEATY ET AL. 9i JAN 80 DRND7...34 ’ UNCLASSIFIED 0{) AD 0Pathogenesis of dengue vaccine viruses in mosquitoes -First Annual Report Barry I. Beaty, Ph.D. Thomas H. G

  9. Dengue vaccine development: strategies and challenges.

    PubMed

    Ramakrishnan, Lakshmy; Pillai, Madhavan Radhakrishna; Nair, Radhakrishnan R

    2015-03-01

    Infection with dengue virus may result in dengue fever or a more severe outcome, such as dengue hemorrhagic syndrome/shock. Dengue virus infection poses a threat to endemic regions for four reasons: the presence of four serotypes, each with the ability to cause a similar disease outcome, including fatality; difficulties related to vector control; the lack of specific treatment; and the nonavailability of a suitable vaccine. Vaccine development is considered challenging due to the severity of the disease observed in individuals who have acquired dengue-specific immunity, either passively or actively. Therefore, the presence of vaccine-induced immunity against a particular serotype may prime an individual to severe disease on exposure to dengue virus. Vaccine development strategies include live attenuated vaccines, chimeric, DNA-based, subunit, and inactivated vaccines. Each of the candidates is in various stages of preclinical and clinical development. Issues pertaining to selection pressures, viral interaction, and safety still need to be evaluated in order to induce a complete protective immune response against all four serotypes. This review highlights the various strategies that have been employed in vaccine development, and identifies the obstacles to producing a safe and effective vaccine.

  10. Inclusion of dengue in TDR's disease portfolio.

    PubMed

    1999-08-01

    This article reports the outcome of the informal consultation of the WHO in-house expert scientists on the proposed inclusion of dengue and tuberculosis in the Training in Tropical Diseases (TDR) portfolio to be reviewed during the 22nd session of the Joint Coordinating Board. The purpose of the meeting was to identify research gaps, pinpoint research needed, and proposed a potential agenda for TDR activities regarding dengue and dengue hemorrhagic fever (DHF). During the meeting, WHO staff presented an analysis of the global situation for dengue and an outline of WHO activities in dengue control and vaccine development. Three discussion groups proposed a list of priority subjects where TDR could initiate activities: 1) in social, economic and behavioral research; 2) in vector research; 3) in diagnosis; 4) in pathophysiology; and 5) in vaccine discovery and development. At present, the only method for controlling or preventing dengue and DHF rely on controlling the mosquito vector. Therefore, developing appropriate and efficient vector control methods, improving laboratory diagnosis and case management of patients, and developing an effective vaccine were the primary objectives of research and capability strengthening.

  11. Pediatric ischemic stroke due to dengue vasculitis.

    PubMed

    Nanda, Subrat Kumar; Jayalakshmi, Sita; Mohandas, Surath

    2014-10-01

    Dengue infection is an important arboviral infection in southeast Asia, especially in India. Neurological manifestations of dengue are increasingly recognized. We report an ischemic stroke due to dengue vasculitis in an 8-year-old child. We present a girl with a short febrile illness followed by episodic severe headache, with gradually progressive hemiparesis and visual impairment. Her brain magnetic resonance imaging revealed multiple infarctions in the anterior and posterior circulation. The magnetic resonance angiogram revealed irregular narrowing of bilateral middle cerebral arteries, right anterior cerebral artery, left posterior cerebral, and bilateral vertebral arteries suggestive of vasculitis. Her dengue serology was strongly positive for immunoglobulin M with 68.9 panbio units. The rest of the evaluation for pediatric stroke was unremarkable. She was treated with intravenous followed by oral corticosteroids and recovered totally with resolution of vasculitis on magnetic resonance angiogram over the next 3 months. This child illustrates possible immune-mediated vasculitis caused by dengue infection which is rather a rare presentation in a child who subsequently recovered well. One should consider dengue in childhood strokes in endemic regions. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Development of Peptide Vaccines in Dengue.

    PubMed

    Reginald, Kavita; Chan, Yanqi; Plebanski, Magdalena; Poh, Chit Laa

    2017-09-13

    Dengue is one of the most important arboviral infection worldwide, infecting up to 390 million people and causing 25,000 deaths annually. Although a licensed dengue vaccine is available, it is not efficacious against dengue serotypes that infect people living in South East Asia, where dengue is an endemic disease. Hence, there is an urgent need to develop an efficient dengue vaccine for this region. Data from different clinical trials indicate that a successful dengue vaccine must elicit both neutralizing antibodies and cell mediated immunity. This can be achieved by designing a multi-epitope peptide vaccine comprising B, CD8+ and CD4+ T cell epitopes. As recognition of T cell epitopes are restricted by human leukocyte antigens (HLA), T cell epitopes which are able to recognize several major HLAs will be preferentially included in the vaccine design. While peptide vaccines are safe, biocompatible and cost-effective, it is poorly immunogenic. Strategies to improve its immunogenicity by the use of long peptides, adjuvants and nanoparticle delivery mechanisms are discussed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  13. Dengue mortality in Colombia, 1985-2012.

    PubMed

    Chaparro-Narváez, Pablo; León-Quevedo, Willian; Castañeda-Orjuela, Carlos Andrés

    2016-02-11

    Dengue in Colombia is an important public health problem due to the huge economic and social costs it has caused, especially during the disease outbreaks.  To describe the behavior of dengue mortality in Colombia between 1985 and 2012.  We conducted a descriptive study. Information was obtained from mortality and population projection databases provided by the Departamento Administrativo Nacional de Estadística (DANE) for the 1985-2012 period. Mortality rates, rate ratios, and case fatality rates were estimated.  A total of 1,990 dengue deaths were registered during this period in Colombia. Dengue mortality rates presented an increasing trend with statistical significance between 1985 and 1998. Higher mortality rates were reported in men both younger than 5 years and older than 65 years. Between 1995 and 2012, category 1 to 4 municipalities reported the highest mortality rates. Case fatality rates varied during the period between 0.01% and 0.39%.  Dengue is an avoidable disease that should disappear from mortality statistics as a cause of death. The event is avoidable if the proposed activities from the Estrategia de Gestión Integrada (EGI)-Dengue are implemented and evaluated. We recommend encouraging the development of an informational culture to contribute to decision making and prioritizing resource allocation.

  14. Antioxidants in patients with dengue viral infection.

    PubMed

    Chandrasena, Lal G; Peiris, Hemantha; Kamani, J; Wanigasuriya, P; Jayaratne, Shantilal D; Wijayasiri, W A A; Wijesekara, G Udaya S

    2014-09-01

    An alteration in the oxidation/reduction (redox) status of humans infected with virus infections may contrioute to tefl pariiogeiiesin anu ciniiua1 manifestations of the disease. Alterations in redox markers begin prior to the onset of clinical symptoms, suggesting early changes in the oxidant/antioxidant balance. Early identification of redox markers may be of clinical usefulness in the management of patients with dengue virus infection. We conducted a hospital based comparative cross sectional study of 55 patients serologically confirmed to have dengue infection and 55 clinically healthy age and sex matched subjects as controls to assess oxidative stress in acute dengue virus infection. Blood samples were drawn on the fifth day after symptom onset and analyzed for Trolox equivalent antioxidant capacity (TEAC), reduced glutathione (GSH), glutathione peroxidase (GPx) and paraoxonase (PON) activity. The results showed significantly lower levels of plasma TEAC, serum PON and erythrocyte GSH and GPx activity among dengue patients than in controls. Of the antioxidants investigated, PON appeared to be the most sensitive marker of oxidative stress in dengue virus infection. Serum PON may be a potentially useful marker of oxidative stress in patients with dengue virus infection.

  15. Backward bifurcations in dengue transmission dynamics.

    PubMed

    Garba, S M; Gumel, A B; Abu Bakar, M R

    2008-09-01

    A deterministic model for the transmission dynamics of a strain of dengue disease, which allows transmission by exposed humans and mosquitoes, is developed and rigorously analysed. The model, consisting of seven mutually-exclusive compartments representing the human and vector dynamics, has a locally-asymptotically stable disease-free equilibrium (DFE) whenever a certain epidemiological threshold, known as the basic reproduction number(R(0)) is less than unity. Further, the model exhibits the phenomenon of backward bifurcation, where the stable DFE coexists with a stable endemic equilibrium. The epidemiological consequence of this phenomenon is that the classical epidemiological requirement of making R(0) less than unity is no longer sufficient, although necessary, for effectively controlling the spread of dengue in a community. The model is extended to incorporate an imperfect vaccine against the strain of dengue. Using the theory of centre manifold, the extended model is also shown to undergo backward bifurcation. In both the original and the extended models, it is shown, using Lyapunov function theory and LaSalle Invariance Principle, that the backward bifurcation phenomenon can be removed by substituting the associated standard incidence function with a mass action incidence. In other words, in addition to establishing the presence of backward bifurcation in models of dengue transmission, this study shows that the use of standard incidence in modelling dengue disease causes the backward bifurcation phenomenon of dengue disease.

  16. Dengue in Bali: Clinical characteristics and genetic diversity of circulating dengue viruses

    PubMed Central

    Yohan, Benediktus; Lestarini, Asri; Hayati, Rahma F.; Meutiawati, Febrina; Suryana, Ketut; Widarsa, Tangking; Budiyasa, Dewa G.; Budiyasa, Ngurah; Myint, Khin S. A.

    2017-01-01

    A high number of dengue cases are reported annually in Bali. Despite the endemicity, limited data on dengue is available for Bali localities. Molecular surveillance study was conducted to explore the clinical and virological characteristics of dengue patients in urban Denpasar and rural Gianyar areas in Bali during the peak season in 2015. A total of 205 adult dengue-suspected patients were recruited in a prospective cross-sectional study. Demographic and clinical information were obtained, and dengue screening was performed using NS1 and IgM/IgG ELISAs. Viral RNA was subsequently extracted from patients’ sera for serotyping using conventional RT-PCR and Simplexa Dengue real-time RT-PCR, followed by genotyping with sequencing method. We confirmed 161 patients as having dengue by NS1 and RT-PCR. Among 154 samples successfully serotyped, the DENV-3 was predominant, followed by DENV-1, DENV-2, and DENV-4. Serotype predominance was different between Denpasar and Gianyar. Genotyping results classify DENV-1 isolates into Genotype I and DENV-2 as Cosmopolitan Genotype. The classification grouped isolates into Genotype I and II for DENV-3 and DENV-4, respectively. Clinical parameters showed no relationship between infecting serotypes and severity. We observed the genetic diversity of circulating DENV isolates and their relatedness with historical data and importation to other countries. Our data highlights the role of this tourist destination as a potential source of dengue transmission in the region. PMID:28531223

  17. Country- and age-specific optimal allocation of dengue vaccines.

    PubMed

    Ndeffo Mbah, Martial L; Durham, David P; Medlock, Jan; Galvani, Alison P

    2014-02-07

    Several dengue vaccines are under development, and some are expected to become available imminently. Concomitant with the anticipated release of these vaccines, vaccine allocation strategies for dengue-endemic countries in Southeast Asia and Latin America are currently under development. We developed a model of dengue transmission that incorporates the age-specific distributions of dengue burden corresponding to those in Thailand and Brazil, respectively, to determine vaccine allocations that minimize the incidence of dengue hemorrhagic fever, taking into account limited availability of vaccine doses in the initial phase of production. We showed that optimal vaccine allocation strategies vary significantly with the demographic burden of dengue hemorrhagic fever. Consequently, the strategy that is optimal for one country may be sub-optimal for another country. More specifically, we showed that, during the first years following introduction of a dengue vaccine, it is optimal to target children for dengue mass vaccination in Thailand, whereas young adults should be targeted in Brazil.

  18. International Dengue Vaccine Communication and Advocacy: Challenges and Way Forward.

    PubMed

    Carvalho, Ana; Van Roy, Rebecca; Andrus, Jon

    2016-01-01

    Dengue vaccine introduction will likely occur soon. However, little has been published on international dengue vaccine communication and advocacy. More effort at the international level is required to review, unify and strategically disseminate dengue vaccine knowledge to endemic countries' decision makers and potential donors. Waiting to plan for the introduction of new vaccines until licensure may delay access in developing countries. Concerted efforts to communicate and advocate for vaccines prior to licensure are likely challenged by unknowns of the use of dengue vaccines and the disease, including uncertainties of vaccine impact, vaccine access and dengue's complex pathogenesis and epidemiology. Nevertheless, the international community has the opportunity to apply previous best practices for vaccine communication and advocacy. The following key strategies will strengthen international dengue vaccine communication and advocacy: consolidating existing coalitions under one strategic umbrella, urgently convening stakeholders to formulate the roadmap for integrated dengue prevention and control, and improving the dissemination of dengue scientific knowledge.

  19. Dengue fever among Israeli expatriates in Delhi, 2015: implications for dengue incidence in Delhi, India.

    PubMed

    Neuberger, Ami; Turgeman, Avigail; Lustig, Yaniv; Schwartz, Eli

    2016-03-01

    We present the data of 13 dengue cases diagnosed between 1 August and 15 September 2015 among 240 Israeli expatriates residing in Delhi. Attack rates were similar between adults (6/128, 4.7%) and children (7/112, 6.3%). dengue virus (DENV-2) was identified in two and DENV-1 in one dengue-seropositive sample. Another febrile patient was diagnosed with chikungunya virus infection. The reported incidence of dengue fever among people living in Delhi was lower than 0.1% as of September 2015. Based on our results, we hypothesize that the incidence of dengue fever in Delhi is grossly underestimated. © International Society of Travel Medicine, 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Transmission spectroscopy of dengue viral infection Transmission spectroscopy of dengue viral infection

    NASA Astrophysics Data System (ADS)

    Firdous, S.; Ahmed, M.; Rehman, A.; Nawaz, M.; Anwar, S.; Murtaza, S.

    2012-04-01

    We presented the rapid diagnostic test for dengue infection based on light spectrum of human blood. The transmission spectra of dengue infected whole blood samples have been recorded in ultra violet to near infrared range (400 - 800 nm) of about 30 conformed infected patients and compared to normal blood samples. Transmission spectra of dengue infected blood illustrate a strong band from 400 - 600 nm with prominant peaks at 540 and 580 nm, where is in case of normal blood below 600 nm, total absorption has been observed. These prominent peaks from 400 - 600 nm are characteristics of cells damage and dangue virus antibodies immunoglobulin G (IgG) and immunoglobulin M (IgM) produced against dengue antigen. The presented diagnostic method is non invasive, cost effective, easy and fast screening technique for dengue infected patients.

  1. Symptomatic Dengue Disease in Five Southeast Asian Countries: Epidemiological Evidence from a Dengue Vaccine Trial

    PubMed Central

    Taurel, Anne-Frieda; Capeding, Maria Rosario; Tran, Ngoc Huu; Hadinegoro, Sri Rezeki; Chotpitayasunondh, Tawee; Chong, Chee Kheong; Wartel, T. Anh; Beucher, Sophie; Frago, Carina; Moureau, Annick; Simmerman, Mark; Laot, Thelma; L’Azou, Maïna; Bouckenooghe, Alain

    2016-01-01

    Dengue incidence has increased globally, but empirical burden estimates are scarce. Prospective methods are best-able to capture all severities of disease. CYD14 was an observer-blinded dengue vaccine study conducted in children 2–14 years of age in Indonesia, Malaysia, Thailand, the Philippines, and Vietnam. The control group received no vaccine and resembled a prospective, observational study. We calculated the rates of dengue according to different laboratory or clinical criteria to make inferences about dengue burden, and compared with rates reported in the passive surveillance systems to calculate expansion factors which describe under-reporting. Over 6,933 person-years of observation in the control group there were 319 virologically confirmed dengue cases, a crude attack rate of 4.6%/year. Of these, 92 cases (28.8%) were clinically diagnosed as dengue fever or dengue hemorrhagic fever by investigators and 227 were not, indicating that most symptomatic disease fails to satisfy existing case definitions. When examining different case definitions, there was an inverse relationship between clinical severity and observed incidence rates. CYD14’s active surveillance system captured a greater proportion of symptomatic dengue than national passive surveillance systems, giving rise to expansion factors ranging from 0.5 to 31.7. This analysis showed substantial, unpredictable and variable under-reporting of symptomatic dengue, even within a controlled clinical trial environment, and emphasizes that burden estimates are highly sensitive to case definitions. These data will assist in generating disease burden estimates and have important policy implications when considering the introduction and health economics of dengue prevention and control interventions. PMID:27532617

  2. Symptomatic Dengue Disease in Five Southeast Asian Countries: Epidemiological Evidence from a Dengue Vaccine Trial.

    PubMed

    Nealon, Joshua; Taurel, Anne-Frieda; Capeding, Maria Rosario; Tran, Ngoc Huu; Hadinegoro, Sri Rezeki; Chotpitayasunondh, Tawee; Chong, Chee Kheong; Wartel, T Anh; Beucher, Sophie; Frago, Carina; Moureau, Annick; Simmerman, Mark; Laot, Thelma; L'Azou, Maïna; Bouckenooghe, Alain

    2016-08-01

    Dengue incidence has increased globally, but empirical burden estimates are scarce. Prospective methods are best-able to capture all severities of disease. CYD14 was an observer-blinded dengue vaccine study conducted in children 2-14 years of age in Indonesia, Malaysia, Thailand, the Philippines, and Vietnam. The control group received no vaccine and resembled a prospective, observational study. We calculated the rates of dengue according to different laboratory or clinical criteria to make inferences about dengue burden, and compared with rates reported in the passive surveillance systems to calculate expansion factors which describe under-reporting. Over 6,933 person-years of observation in the control group there were 319 virologically confirmed dengue cases, a crude attack rate of 4.6%/year. Of these, 92 cases (28.8%) were clinically diagnosed as dengue fever or dengue hemorrhagic fever by investigators and 227 were not, indicating that most symptomatic disease fails to satisfy existing case definitions. When examining different case definitions, there was an inverse relationship between clinical severity and observed incidence rates. CYD14's active surveillance system captured a greater proportion of symptomatic dengue than national passive surveillance systems, giving rise to expansion factors ranging from 0.5 to 31.7. This analysis showed substantial, unpredictable and variable under-reporting of symptomatic dengue, even within a controlled clinical trial environment, and emphasizes that burden estimates are highly sensitive to case definitions. These data will assist in generating disease burden estimates and have important policy implications when considering the introduction and health economics of dengue prevention and control interventions.

  3. Dengue specific immunoglobulins M, A, and E in primary and secondary dengue 4 infected Salvadorian children.

    PubMed

    Vazquez, Susana; Lozano, Celina; Perez, Ana Beatriz; Castellanos, Yinet; Ruiz, Didye; Calzada, Naifi; Guzmán, Maria Guadalupe

    2014-09-01

    El Salvador is a Central American country that has been affected by several dengue outbreaks. This study investigated the levels of IgM, IgA, and IgE anti-dengue antibodies in serum samples from children in El Salvador, with a clinical and serological diagnosis of dengue infection during the dengue 4 outbreak in 2002-2003. Seventy one serum samples were tested by ELISA and cases were classified in three groups: 13 primary dengue fever (PDF), 21 secondary dengue fever (SDF), and 37 secondary dengue hemorrhagic fever (SDHF). Also, the specificity of anti-dengue IgM for the different serotypes was tested. No significant differences in the IgM response were found between PDF and SDF, but these were detected between PDF and SDHF (P = 0.0053) and between SDF and SDHF (P = 0.0003). The IgA and IgE values showed a statistically significant difference between primary and secondary groups. The highest positivity percentage of IgA was between 95% (SDF) and 100% (SDHF) towards day 7 of onset of fever. All secondary cases were positive for IgE antibodies. The specificity of IgM was determined for DENV-4 virus in primary and secondary DF groups. This is the first study on dengue cases in Salvadorian children related to the immune response of different immunoglobulins to the type of infection and the clinical picture. Further prospective studies are needed to define if the pattern of immunoglobulins can determine early dengue infection and/or severity. © 2013 Wiley Periodicals, Inc.

  4. Dengue in the Americas and Southeast Asia: do they differ?

    PubMed

    Halstead, Scott B

    2006-12-01

    The populations of Southeast Asia (SE Asia) and tropical America are similar, and all four dengue viruses of Asian origin are endemic in both regions. Yet, during comparable 5-year periods, SE Asia experienced 1.16 million cases of dengue hemorrhagic fever (DHF), principally in children, whereas in the Americas there were 2.8 million dengue fever (DF) cases, principally in adults, and only 65,000 DHF cases. This review aims to explain these regional differences. In SE Asia, World War II amplified Aedes aegypti populations and the spread of dengue viruses. In the Americas, efforts to eradicate A. aegypti in the 1940s and 1950s contained dengue epidemics mainly to the Caribbean Basin. Cuba escaped infections with the American genotype dengue-2 and an Asian dengue-3 endemic in the 1960s and 1970s. Successive infections with dengue-1 and an Asian genotype dengue-2 resulted in the 1981 DHF epidemic. When this dengue-2 virus was introduced in other Caribbean countries, it encountered populations highly immune to the American genotype dengue-2. During the 1980s and 1990s, rapidly expanding populations of A. aegypti in Brazil permitted successive epidemics of dengue-1, -2, and -3. These exposures, however, resulted mainly in DF, with surprisingly few cases of DHF. The absence of high rates of severe dengue disease in Brazil, as elsewhere in the Americas, may be partly explained by the widespread prevalence of human dengue resistance genes. Understanding the nature and distribution of these genes holds promise for containing severe dengue. Future research on dengue infections should emphasize population-based designs.

  5. Superensemble forecasts of dengue outbreaks

    PubMed Central

    Kandula, Sasikiran; Shaman, Jeffrey

    2016-01-01

    In recent years, a number of systems capable of predicting future infectious disease incidence have been developed. As more of these systems are operationalized, it is important that the forecasts generated by these different approaches be formally reconciled so that individual forecast error and bias are reduced. Here we present a first example of such multi-system, or superensemble, forecast. We develop three distinct systems for predicting dengue, which are applied retrospectively to forecast outbreak characteristics in San Juan, Puerto Rico. We then use Bayesian averaging methods to combine the predictions from these systems and create superensemble forecasts. We demonstrate that on average, the superensemble approach produces more accurate forecasts than those made from any of the individual forecasting systems. PMID:27733698

  6. Unusual Presentation of Dengue Fever

    PubMed Central

    Aslam, Moaz; Aleem, Numra A.; Zahid, Mohammad F.; Rahman, Arshalooz J.

    2016-01-01

    Dengue fever (DF) is an acute febrile illness that follows a self-limiting course. However, some patients suffer from complications, including myocarditis, due to the involvement of other organs. A child presented at the Aga Khan University Hospital in Karachi, Pakistan, in June 2013 with a high-grade fever, malaise and epigastric pain radiating to the chest. Positive DF antigen and immunoglobulin M assays confirmed the diagnosis of DF. Persistent bradycardia with low blood pressure led to further cardiac investigations which showed a decreased ejection fraction and raised serum cardiac enzymes, indicating myocardial damage. With supportive care and use of inotropes, the spontaneous normalisation of cardiac enzyme levels and ejection fraction was observed. The child was discharged five days after admission. This case highlights the importance of identifying myocarditis in DF patients suffering from cardiac symptoms that are not explained by other potential aetiologies. Awareness, early suspicion and supportive care are essential to ensure favourable outcomes. PMID:26909198

  7. Describing dengue epidemics: Insights from simple mechanistic models

    NASA Astrophysics Data System (ADS)

    Aguiar, Maíra; Stollenwerk, Nico; Kooi, Bob W.

    2012-09-01

    We present a set of nested models to be applied to dengue fever epidemiology. We perform a qualitative study in order to show how much complexity we really need to add into epidemiological models to be able to describe the fluctuations observed in empirical dengue hemorrhagic fever incidence data offering a promising perspective on inference of parameter values from dengue case notifications.

  8. Dengue Virus 1 Outbreak in Buenos Aires, Argentina, 2016.

    PubMed

    Tittarelli, Estefanía; Lusso, Silvina B; Goya, Stephanie; Rojo, Gabriel L; Natale, Mónica I; Viegas, Mariana; Mistchenko, Alicia S; Valinotto, Laura E

    2017-10-01

    The largest outbreak of dengue in Buenos Aires, Argentina, occurred during 2016. Phylogenetic, phylodynamic, and phylogeographic analyses of 82 samples from dengue patients revealed co-circulation of 2 genotype V dengue virus lineages, suggesting that this virus has become endemic to the Buenos Aires metropolitan area.

  9. Fatal Fulminant Hepatic Failure in a Diabetic with Primary Dengue

    PubMed Central

    Viswanathan, Stalin; Iqbal, Nayyar; Anemon, P. Philip; Kumar, G. Shyam

    2010-01-01

    We report a 49-year-old diabetic with dengue hemorrhagic fever who developed fulminant hepatitis, severe coagulopathy, shock, and refractory metabolic acidosis and died on the eighth day of illness. This is the only second report of an adult with fatal fulminant hepatic failure due to dengue, and the first case arising from a primary dengue infection. PMID:21234316

  10. Management of dengue in Australian travellers: a retrospective multicentre analysis.

    PubMed

    Tai, Alex Yc; McGuinness, Sarah L; Robosa, Roselle; Turner, David; Huang, G Khai Lin; Leder, Karin; Korman, Tony M; Thevarajan, Irani; Stewardson, Andrew J; Padiglione, Alexander A; Johnson, Douglas F

    2017-04-17

    To describe the epidemiology, clinical and laboratory features and outcomes of dengue in returned Australian travellers, applying the revised WHO dengue classification (2009) to this population. Retrospective case series analysis of confirmed dengue cases hospitalised at one of four Australian tertiary hospitals, January 2012 - May 2015. Clinical features, laboratory findings and outcomes of patients with dengue; dengue classification according to 2009 WHO guidelines. 208 hospitalised patients (median age, 32 years; range, 4-76 years) were included in the study. Dengue was most frequently acquired in Indonesia (94 patients, 45%) and Thailand (40, 19%). The most common clinical features were fever (98% of patients) and headache (76%). 84 patients (40%) met the WHO criteria for dengue with warning signs, and one the criteria for severe dengue; the most common warning signs were mucosal bleeding (44 patients, 21%) and abdominal pain (43, 21%). Leukopenia (176 patients, 85%), thrombocytopenia (133, 64%), and elevated liver enzyme levels (154, 76%) were the most common laboratory findings. 46 patients (22%) had serological evidence of previous exposure to dengue virus. WHO guidelines were documented as a management benchmark in ten cases (5%); 46 patients (22%) received non-steroidal anti-inflammatory drugs (NSAIDs). A significant proportion of returning Australian travellers hospitalised for dengue have unrecognised warning signs of severe disease. Many received NSAIDs, which can increase the risk of haemorrhage in dengue. As travel to Asia from Australia continues to increase, it is vital for averting serious outcomes that clinicians can recognise and manage dengue.

  11. Reemergence and Autochthonous Transmission of Dengue Virus, Eastern China, 2014.

    PubMed

    Wang, Wen; Yu, Bin; Lin, Xian-Dan; Kong, De-Guang; Wang, Jian; Tian, Jun-Hua; Li, Ming-Hui; Holmes, Edward C; Zhang, Yong-Zhen

    2015-09-01

    In 2014, 20 dengue cases were reported in the cities of Wenzhou (5 cases) and Wuhan (15 cases), China, where dengue has rarely been reported. Dengue virus 1 was detected in 4 patients. Although most of these cases were likely imported, epidemiologic analysis provided evidence for autochthonous transmission.

  12. Seroprevalence of acute dengue in a Malaysian tertiary medical centre

    PubMed Central

    Ding, Chuan Hun; Rashid, Zetti Zainol; Rahman, Md. Mostafizur; Khang, NanFeng; Low, Wan Ngor; Hussin, Nurabrar; Marzuki, Melissa Iqlima; Jaafar, Alyaa Nadhira; Roslan, Nurul Ain’ Nabilla; Chandrasekaran, Terukumar

    2016-01-01

    Objectives: The aims of this study were to determine the seroprevalence of acute dengue in Universiti Kebangsaan Malaysia (UKM) Medical Centre and its correlation with selected haematological and biochemical parameters. Methods: This cross-sectional study was conducted from January to June 2015. A patient was serologically diagnosed with acute dengue if the dengue virus IgG, IgM or NS-1 antigen was reactive. Results: Out of 1,774 patients suspected to have acute dengue, 1,153 were serologically diagnosed with the infection, resulting in a seroprevalence of 64.9%. Dengue-positive patients had a lower mean platelet count (89 × 109/L) compared to the dengue-negative patients (171 × 109/L) (p<0.0001). The mean total white cell count was also lower in the dengue-positive cases (4.7 × 109/L vs. 7.2 × 109/L; p<0.0001). The mean haematocrit was higher in patients with acute dengue (42.5% vs. 40.0%; p<0.0001). Likewise, the serum alanine transaminase level was also higher in patients with acute dengue (108 U/L vs. 54 U/L; p<0.0001). Conclusions: Dengue is very prevalent in UKM Medical Centre as most patients suspected to have acute dengue had serological evidence of the infection. The platelet count was the single most likely parameter to be abnormal (i.e. low) in patients with acute dengue. PMID:27182269

  13. Differential proteomic analysis of virus-enriched fractions obtained from plasma pools of patients with dengue fever or severe dengue.

    PubMed

    Fragnoud, Romain; Flamand, Marie; Reynier, Frederic; Buchy, Philippe; Duong, Vasna; Pachot, Alexandre; Paranhos-Baccala, Glaucia; Bedin, Frederic

    2015-11-14

    Dengue is the most widespread mosquito-borne viral disease of public health concern. In some patients, endothelial cell and platelet dysfunction lead to life-threatening hemorrhagic dengue fever or dengue shock syndrome. Prognostication of disease severity is urgently required to improve patient management. The pathogenesis of severe dengue has not been fully elucidated, and the role of host proteins associated with viral particles has received little exploration. The proteomes of virion-enriched fractions purified from plasma pools of patients with dengue fever or severe dengue were compared. Virions were purified by ultracentrifugation combined with a water-insoluble polyelectrolyte-based technique. Following in-gel hydrolysis, peptides were analyzed by nano-liquid chromatography coupled to ion trap mass spectrometry and identified using data libraries. Both dengue fever and severe dengue viral-enriched fractions contained identifiable viral envelope proteins and host cellular proteins. Canonical pathway analysis revealed the identified host proteins are mainly involved in the coagulation cascade, complement pathway or acute phase response signaling pathway. Some host proteins were over- or under-represented in plasma from patients with severe dengue compared to patients with dengue fever. ELISAs were used to validate differential expression of a selection of identified host proteins in individual plasma samples of patients with dengue fever compared to patients with severe dengue. Among 22 host proteins tested, two could differentiate between dengue fever and severe dengue in two independent cohorts (olfactomedin-4: area under the curve (AUC), 0.958; and platelet factor-4: AUC, 0.836). A novel technique of virion-enrichment from plasma has allowed to identify two host proteins that have prognostic value for classifying patients with acute dengue who are more likely to develop a severe dengue. The impact of these host proteins on pathogenicity and disease outcome

  14. Awareness of dengue and practice of dengue control among the semi-urban community: a cross sectional survey.

    PubMed

    Naing, Cho; Ren, Wong Yih; Man, Chan Yuk; Fern, Koh Pei; Qiqi, Chua; Ning, Choo Ning; Ee, Clarice Wong Syun

    2011-12-01

    Primary prevention is the most effective measure in dengue prevention and control. The objectives were (i) to determine the level of knowledge and practice of dengue control amongst the study community, and (ii) to explore the factors affecting practice of dengue control in the study area. A cross-sectional study was conducted in a semi-urban Town of Malaysia, using a structured questionnaire covering sociodemography, knowledge related to dengue, knowledge related to Aedes mosquito and preventive measures against the disease. For comparison of survey responses, chi-square test was applied for categorical data. To explore the factors affecting the practice of dengue control, a linear regression model was introduced. Almost all of the respondents (95%) had heard about dengue. Overall, misconceptions of dengue transmission were identified and the practice of dengue control in the study population was insufficient. About half (50.5%) had misconceptions that Aedes can breed in dirty water and the preferred biting time is dusk or sunset (45.6%). Only 44.5% of the households surveyed had covered their water containers properly. Significant associations were found between knowledge scores of dengue and age (P = 0.001), education level (P = 0.001), marital status (P = 0.012), and occupation (P = 0.007). In regression analysis, only the knowledge of dengue was significantly and positively associated with practice on dengue control. A future study with larger samples and more variables to assess the knowledge, attitudes and practices of dengue control is recommended.

  15. Epidemiology of dengue: past, present and future prospects

    PubMed Central

    Murray, Natasha Evelyn Anne; Quam, Mikkel B; Wilder-Smith, Annelies

    2013-01-01

    Dengue is currently regarded globally as the most important mosquito-borne viral disease. A history of symptoms compatible with dengue can be traced back to the Chin Dynasty of 265–420 AD. The virus and its vectors have now become widely distributed throughout tropical and subtropical regions of the world, particularly over the last half-century. Significant geographic expansion has been coupled with rapid increases in incident cases, epidemics, and hyperendemicity, leading to the more severe forms of dengue. Transmission of dengue is now present in every World Health Organization (WHO) region of the world and more than 125 countries are known to be dengue endemic. The true impact of dengue globally is difficult to ascertain due to factors such as inadequate disease surveillance, misdiagnosis, and low levels of reporting. Currently available data likely grossly underestimates the social, economic, and disease burden. Estimates of the global incidence of dengue infections per year have ranged between 50 million and 200 million; however, recent estimates using cartographic approaches suggest this number is closer to almost 400 million. The expansion of dengue is expected to increase due to factors such as the modern dynamics of climate change, globalization, travel, trade, socioeconomics, settlement and also viral evolution. No vaccine or specific antiviral therapy currently exists to address the growing threat of dengue. Prompt case detection and appropriate clinical management can reduce the mortality from severe dengue. Effective vector control is the mainstay of dengue prevention and control. Surveillance and improved reporting of dengue cases is also essential to gauge the true global situation as indicated in the objectives of the WHO Global Strategy for Dengue Prevention and Control, 2012–2020. More accurate data will inform the prioritization of research, health policy, and financial resources toward reducing this poorly controlled disease. The objective

  16. Dengue in an area of the Colombian Caribbean

    PubMed Central

    Rodríguez-Barreto, Heidi; Mattar-Velilla, Salim

    2015-01-01

    Background: In Colombia, dengue is an endemic disease and the four serotypes have been reported. Objective: To describe the frequency and severity of dengue in an area of the Colombian Caribbean (Department of Cordoba) Methods: A retrospective study was conducted. Two data sources were analysed: The database from the Direction of Health in Córdoba, and clinical registers of patients diagnosed with haemorrhagic fevers and fevers of unknown origin in reference hospitals. Results: The mean incidence of dengue between 2003-2010 was 36.5 cases/105 inhabitants (CI95%: 34.3-37.5) and adjusted for sub-reporting, could be between 178.5 and 521.6. The mean incidence of severe dengue was 4.7 cases/105 inhabitants (CI95%: 4.3-5.0). Mean mortality rate due to dengue was 0.3 cases/105 inhabitants. The fatality rate was below 1%. The mean total leukocyte count in patients with dengue was 6,181 mm3 (CI95%: 5,973-6,389) and with severe Dengue was 4,729 mm3 (CI95%: 4,220-5,238). The average platelet count in patients with Dengue was 118,793/mm3 (CI95%: 107,255-130,331) and in patients with Severe Dengue 77,655 (CI95%: 59,640-95,670). Both differences were statistically significant (p <0.05). The frequency of laboratories test per patient in patients with Dengue and severe Dengue were different. Conclusion: The department of Cordoba is a highly endemic zone of Dengue and severe Dengue in the Colombian Caribbean. Moreover, the results show significant differences between dengue and severe dengue so much in tests as in frequency of use of healthcare services. PMID:26019378

  17. Analysis of the Optimal Vaccination Age for Dengue in Brazil with a Tetravalent Dengue Vaccine.

    PubMed

    Maier, Sandra B; Huang, Xiao; Massad, Eduardo; Amaku, Marcos; Burattini, Marcelo N; Greenhalgh, David

    2017-09-18

    In this paper we study a mathematical model to analyse the optimal vaccination age against Dengue in Brazil. Data from Brazil are used to estimate the basic reproduction numbers for each of the four Dengue serotypes and then the optimal vaccination age is calculated using a method due to Hethcote [1]. The vaccine has different efficacies against each serotype. Vaccination that is too early is ineffective as individuals are protected by maternal antibodies but leaving vaccination until later may allow the disease to spread. First of all the optimal vaccination ages are calculated where there is just one serotype in circulation and then when there are multiple serotypes. The calculations are done using data both assuming constant vaccine efficacy and age-dependent vaccine efficacy against a given serotype. The multiple serotype calculations are repeated assuming that the first infection is a risky infection and that it is not (to model Dengue Antibody Enhancement). The calculations are then repeated when any third or fourth Dengue infections are asymptomatic, so that two Dengue infections with different serotypes provide effective permanent immunity. The calculations are also repeated when the age-dependent risk function (fitted to Brazilian data) is hospitalisation from Dengue and when it is mortality due to Dengue. We find a wide variety of optimal vaccination ages depending on both the serotypes in circulation and the assumptions of the model. Copyright © 2017. Published by Elsevier Inc.

  18. Dengue Virus Genome Uncoating Requires Ubiquitination.

    PubMed

    Byk, Laura A; Iglesias, Néstor G; De Maio, Federico A; Gebhard, Leopoldo G; Rossi, Mario; Gamarnik, Andrea V

    2016-06-28

    The process of genome release or uncoating after viral entry is one of the least-studied steps in the flavivirus life cycle. Flaviviruses are mainly arthropod-borne viruses, including emerging and reemerging pathogens such as dengue, Zika, and West Nile viruses. Currently, dengue virus is one of the most significant human viral pathogens transmitted by mosquitoes and is responsible for about 390 million infections every year around the world. Here, we examined for the first time molecular aspects of dengue virus genome uncoating. We followed the fate of the capsid protein and RNA genome early during infection and found that capsid is degraded after viral internalization by the host ubiquitin-proteasome system. However, proteasome activity and capsid degradation were not necessary to free the genome for initial viral translation. Unexpectedly, genome uncoating was blocked by inhibiting ubiquitination. Using different assays to bypass entry and evaluate the first rounds of viral translation, a narrow window of time during infection that requires ubiquitination but not proteasome activity was identified. In this regard, ubiquitin E1-activating enzyme inhibition was sufficient to stabilize the incoming viral genome in the cytoplasm of infected cells, causing its retention in either endosomes or nucleocapsids. Our data support a model in which dengue virus genome uncoating requires a nondegradative ubiquitination step, providing new insights into this crucial but understudied viral process. Dengue is the most significant arthropod-borne viral infection in humans. Although the number of cases increases every year, there are no approved therapeutics available for the treatment of dengue infection, and many basic aspects of the viral biology remain elusive. After entry, the viral membrane must fuse with the endosomal membrane to deliver the viral genome into the cytoplasm for translation and replication. A great deal of information has been obtained in the last decade

  19. Clinically Profiling Pediatric Patients with Dengue

    PubMed Central

    Pothapregada, Sriram; Kamalakannan, Banupriya; Thulasingham, Mahalaskhmy; Sampath, Srinivasan

    2016-01-01

    Objective: To study the clinical profile and outcome of dengue fever in children at a tertiary care hospital in Puducherry. Materials and Methods: All children (0-12 years of age) diagnosed and confirmed as dengue fever from August 2012 to January 2015 were reviewed retrospectively from hospital case records as per the revised World Health Organization guidelines for dengue fever. The diagnosis was confirmed by NS1 antigen-based ELISA test or dengue serology for IgM and IgG antibodies, and the data were analyzed using SPSS 16.0 statistical software. After collecting the data, all the variables were summarized by descriptive statistics. Results: Among the 261 confirmed cases of dengue fever non-severe and severe dengue infection was seen in 60.9% and 39.1%, respectively. The mean age (standard deviation) of the presentation was 6.9 + 3.3 years and male: female ratio was 1.2:1. The most common clinical manifestations were fever (94.6%), conjunctival congestion (89.6%), myalgia (81.9%), coryza (79.7%), headache (75.1%), palmar erythema (62.8%), and retro-orbital pain (51.3%). The common early warning signs at the time of admission were persistent vomiting (75.1%), liver enlargement (59.8%), cold and clammy extremities (45.2%), pain abdomen (31.0%), hypotension (29.5%), restlessness (26.4%), giddiness (23.0%), bleeding (19.9%), and oliguria (18.4%). The common manifestation of severe dengue infection was shock (39.1%), bleeding (19.9%), and multi-organ dysfunction (2.3%). The most common complications were liver dysfunction, acute respiratory distress syndrome, encephalopathy, pleural effusion, ascites, myocarditis, myositis, acute kidney injury, and disseminated intravascular coagulopathy. Platelet count did not always correlate well with the severity of bleeding. There were six deaths (2.3%) and out of them four presented with impaired consciousness (66.6%). The common causes for poor outcome were multiorgan failure, encephalopathy, and fluid refractory shock

  20. Climatic factors influencing dengue cases in Dhaka city: A model for dengue prediction

    PubMed Central

    Karim, Md. Nazmul; Munshi, Saif Ullah; Anwar, Nazneen; Alam, Md. Shah

    2012-01-01

    Background & objectives: Transmission of dengue virus depends on the presence of Aedes mosquito. Mosquito generation and development is known to be influenced by the climate. This study was carried out to examine whether the climatic factors data can be used to predict yearly dengue cases of Dhaka city, Bangladesh. Methods: Monthly reported dengue cases and climate data for the years 2000–2008 were obtained from the Directorate General of Health Services (DGHS) and Meteorological Department of Dhaka, Bangladesh, respectively. Data for the period 2000 to 2007 were used for development of a model through multiple linear regressions. Retrospective validation of the model was done with 2001, 2003, 2005 and 2008 data. Log transformation of the dependent variable was done to normalize data for linear regression. Average monthly humidity, rainfall, minimum and maximum temperature were used as independent variables and number of dengue cases reported monthly was used as dependent variable. Accuracy of the model for predicting outbreak was assessed through receiver operative characteristics (ROC) curve. Results: Climatic factors, i.e. rainfall, maximum temperature and relative humidity were significantly correlated with monthly reported dengue cases. The model incorporating climatic data of two-lag month explained 61 per cent of variation in number of reported dengue cases and this model was found to predict dengue outbreak (≥ 200 cases) with considerable accuracy [area under ROC curve = 0.89, 95%CI = (0.89-0.98)]. Interpretation & conclusions: Our results showed that the climate had a major effect on the occurrence of dengue infection in Dhaka city. Though the prediction model had some limitations in predicting the monthly number of dengue cases, it could forecast possible outbreak two months in advance with considerable accuracy. PMID:22885261

  1. Dengue vaccine: local decisions, global consequences.

    PubMed

    López-Gatell, Hugo; Alpuche-Aranda, Celia M; Santos-Preciado, José I; Hernández-Ávila, Mauricio

    2016-11-01

    As new vaccines against diseases that are prevalent in low- and middle-income countries gradually become available, national health authorities are presented with new regulatory and policy challenges. The use of CYD-TDV - a chimeric tetravalent, live-attenuated dengue vaccine - was recently approved in five countries. Although promising for public health, this vaccine has only partial and heterogeneous efficacy and may have substantial adverse effects. In trials, children who were aged 2-5 years when first given CYD-TDV were seven times more likely to be hospitalized for dengue, in the third year post-vaccination, than their counterparts in the control group. As it has not been clarified whether this adverse effect is only a function of age or is determined by dengue serostatus, doubts have been cast over the long-term safety of this vaccine in seronegative individuals of any age. Any deployment of the vaccine, which should be very cautious and only considered after a rigorous evaluation of the vaccine's risk-benefit ratio in explicit national and subnational scenarios, needs to be followed by a long-term assessment of the vaccine's effects. Furthermore, any implementation of dengue vaccines must not weaken the political and financial support of preventive measures that can simultaneously limit the impacts of dengue and several other mosquito-borne pathogens.

  2. Homotypic Dengue Virus Reinfections in Nicaraguan Children

    PubMed Central

    Waggoner, Jesse J.; Balmaseda, Angel; Gresh, Lionel; Sahoo, Malaya K.; Montoya, Magelda; Wang, Chunling; Abeynayake, Janaki; Kuan, Guillermina; Pinsky, Benjamin A.; Harris, Eva

    2016-01-01

    Background. Infection with any of the 4 related dengue virus serotypes (DENV-1–4) is thought to result in lifelong immunity to homotypic reinfection (ie, reinfection with the same serotype). Methods. Archived serum samples collected as part of an ongoing pediatric dengue cohort study in Nicaragua were tested for DENV by real-time reverse transcription polymerase chain reaction. Samples were collected from 2892 children who presented with an acute febrile illness clinically attributed to a non-DENV cause (hereafter, “C cases”). Test results were added to a database of previously identified symptomatic dengue cases in the cohort to identify repeat infections. Results. Four patients with homotypic DENV reinfections were identified and confirmed among 29 repeat DENV infections (13.8%) with serotype confirmation. Homotypic reinfections with DENV-1, DENV-2, and DENV-3 occurred 325–621 days after the initial infection. Each patient experienced 1 symptomatic dengue case and 1 DENV-positive C case, and 2 patients presented with symptomatic dengue during their second infection. These DENV-positive C cases did not elicit long-lived humoral immune responses, despite viremia levels of up to 6.44 log10 copies per mL of serum. Conclusions. We describe the first set of virologically confirmed homotypic DENV reinfections. Such cases challenge the current understanding of DENV immunity and have important implications for modeling DENV transmission. PMID:26984144

  3. Validation of dengue infection severity score

    PubMed Central

    Pongpan, Surangrat; Patumanond, Jayanton; Wisitwong, Apichart; Tawichasri, Chamaiporn; Namwongprom, Sirianong

    2014-01-01

    Objective To validate a simple scoring system to classify dengue viral infection severity to patients in different settings. Methods The developed scoring system derived from 777 patients from three tertiary-care hospitals was applied to 400 patients in the validation data obtained from another three tertiary-care hospitals. Percentage of correct classification, underestimation, and overestimation was compared. The score discriminative performance in the two datasets was compared by analysis of areas under the receiver operating characteristic curves. Results Patients in the validation data were different from those in the development data in some aspects. In the validation data, classifying patients into three severity levels (dengue fever, dengue hemorrhagic fever, and dengue shock syndrome) yielded 50.8% correct prediction (versus 60.7% in the development data), with clinically acceptable underestimation (18.6% versus 25.7%) and overestimation (30.8% versus 13.5%). Despite the difference in predictive performances between the validation and the development data, the overall prediction of the scoring system is considered high. Conclusion The developed severity score may be applied to classify patients with dengue viral infection into three severity levels with clinically acceptable under- or overestimation. Its impact when used in routine clinical practice should be a topic for further study. PMID:24623999

  4. Dengue vaccine: local decisions, global consequences

    PubMed Central

    López-Gatell, Hugo; Alpuche-Aranda, Celia M; Santos-Preciado, José I

    2016-01-01

    Abstract As new vaccines against diseases that are prevalent in low- and middle-income countries gradually become available, national health authorities are presented with new regulatory and policy challenges. The use of CYD-TDV – a chimeric tetravalent, live-attenuated dengue vaccine – was recently approved in five countries. Although promising for public health, this vaccine has only partial and heterogeneous efficacy and may have substantial adverse effects. In trials, children who were aged 2–5 years when first given CYD-TDV were seven times more likely to be hospitalized for dengue, in the third year post-vaccination, than their counterparts in the control group. As it has not been clarified whether this adverse effect is only a function of age or is determined by dengue serostatus, doubts have been cast over the long-term safety of this vaccine in seronegative individuals of any age. Any deployment of the vaccine, which should be very cautious and only considered after a rigorous evaluation of the vaccine’s risk–benefit ratio in explicit national and subnational scenarios, needs to be followed by a long-term assessment of the vaccine’s effects. Furthermore, any implementation of dengue vaccines must not weaken the political and financial support of preventive measures that can simultaneously limit the impacts of dengue and several other mosquito-borne pathogens. PMID:27821888

  5. [Clinical and epidemiological characteristic of dengue].

    PubMed

    Murillo-Llanes, Joel; Soto-Valenzuela, Humberto; Flores-Flores, Paula; Peraza-Garay, Felipe

    2007-01-01

    To describe the clinical and epidemiological characteristics of dengue fever (DF) and dengue hemorrhagic fever (DHF). A cross-sectional study was conducted in the Hospital General de Culiacan Dr. Bernardo J. Gastélum and the Hospital General de Zona 28 of IMSS from September to November 2003, with patients having dengue diagnosis, which was classified according to the WHO criteria. The statistical program Stata v6 was used for the analysis. 231 dengue cases (DF: 90.48 %; DHF 9.52 %) were included. Average age was 34.5 +/- 15 years. 61.7% of DF cases were women, while 77.3% of DHF cases were men. DHF cases went to the hospital in 4.7 +/- 2 days, while DF cases went in 3.4 +/- 2.2 days (p = 0.004). DHF cases had more often headache, retroocular pain, arthralgias, diarrhea and vomiting (p < 0.05). DF cases showed hemorrhagic manifestations (24.8%); plasma leakage (6.7%) and thrombocytopenia (34.4%); petequiae, gingival bleeding and epistaxis were associated to thrombocytopenia below 39 000/mm(3) (p < 0.05); neutropenia, prolonged partial thromboplastin time elevated transaminases were observed more often in DHF cases (p <0.05). the main variables associated with DHF were: male gender, fever, vomiting and gingival bleeding but not previous history of dengue; the major hemoconcentration, the major severity of thrombocytopenia.

  6. Dengue Vectors and their Spatial Distribution

    PubMed Central

    Higa, Yukiko

    2011-01-01

    The distribution of dengue vectors, Ae. aegypti and Ae. albopictus, is affected by climatic factors. In addition, since their life cycles are well adapted to the human environment, environmental changes resulting from human activity such as urbanization exert a great impact on vector distribution. The different responses of Ae. aegypti and Ae albopictus to various environments result in a difference in spatial distribution along north-south and urban-rural gradients, and between the indoors and outdoors. In the north-south gradient, climate associated with survival is an important factor in spatial distribution. In the urban-rural gradient, different distribution reflects a difference in adult niches and is modified by geographic and human factors. The direct response of the two species to the environment around houses is related to different spatial distribution indoors and outdoors. Dengue viruses circulate mainly between human and vector mosquitoes, and the vector presence is a limiting factor of transmission. Therefore, spatial distribution of dengue vectors is a significant concern in the epidemiology of the disease. Current technologies such as GIS, satellite imagery and statistical models allow researchers to predict the spatial distribution of vectors in the changing environment. Although it is difficult to confirm the actual effect of environmental and climate changes on vector abundance and vector-borne diseases, environmental changes caused by humans and human behavioral changes due to climate change can be expected to exert an impact on dengue vectors. Longitudinal monitoring of dengue vectors and viruses is therefore necessary. PMID:22500133

  7. Gravitraps for management of dengue clusters in Singapore.

    PubMed

    Lee, Caleb; Vythilingam, Indra; Chong, Chee-Seng; Abdul Razak, Muhammad Aliff; Tan, Cheong-Huat; Liew, Christina; Pok, Kwoon-Yong; Ng, Lee-Ching

    2013-05-01

    Although Singapore has an intensive dengue control program, dengue remains endemic with regular outbreaks. We report development and use of a novel adult oviposition trap, the Gravitrap, in managing dengue cluster areas. The Gravitrap is a simple, hay infusion-filled cylindrical trap with a sticky inner surface to serve as an oviposition site for gravid female Aedes mosquitoes. Wire gauze fitted above the water level minimizes the risk of it being an unwanted breeding habitat. The Gravitrap was deployed in 11 dengue cluster areas throughout Singapore. Aedes aegypti was the predominant mosquito caught in the trap and some (5.73%) were found to be positive for dengue virus.

  8. Current Status of Dengue Therapeutics Research and Development

    PubMed Central

    Ooi, Eng Eong; Vasudevan, Subhash G.

    2017-01-01

    Abstract Dengue is a significant global health problem. Even though a vaccine against dengue is now available, which is a notable achievement, its long-term protective efficacy against each of the 4 dengue virus serotypes remains to be definitively determined. Consequently, drugs directed at the viral targets or critical host mechanisms that can be used safely as prophylaxis or treatment to effectively ameliorate disease or reduce disease severity and fatalities are still needed to reduce the burden of dengue. This review will provide a brief account of the status of therapeutics research and development for dengue. PMID:28403438

  9. Dengue Fever with rectus sheath hematoma: a case report.

    PubMed

    Sharma, Anurag; Bhatia, Sonia; Singh, Rajendra Pratap; Malik, Gaurav

    2014-04-01

    Dengue fever, also known as breakbone fever, is an infectious tropical disease caused by the Dengue virus. It is associated with a number of complications, which are well documented. However, Dengue fever associated with rectus sheath hematoma (RSH) is a very rare complication. Only one case report has been published prior supporting the association of Dengue fever with RSH. We report a case of Dengue fever who presented with RSH and was successfully treated conservatively. RSH is also an uncommon cause of acute abdominal pain. It is accumulation of blood in the sheath of the rectus abdominis, secondary to rupture of an epigastric vessel or muscle tear.

  10. Severe thrombotic events associated with dengue fever, Brazil.

    PubMed

    da Costa, Paulo Sérgio Gonçalves; Ribeiro, Geyza Machado; Junior, Cleber Soares; da Costa Campos, Lenilton

    2012-10-01

    Dengue fever has been a major problem in hospital settings in Brazil for the past 15 years. The main concern has been the severe forms, i.e., dengue hemorrhagic fever and dengue shock syndrome. Hemorrhagic events of different degrees have also been a major concern. We report five cases of large vein thrombotic events associated with the acute phase of dengue fever, including a previously non-reported case of mesenteric vein thrombosis. Complications such as these could have been overlooked in the diagnosis of dengue fever, given that the major concern is the hemorrhagic event.

  11. Understanding the relative importance of global dengue risk factors.

    PubMed

    Lowe, Rachel

    2015-10-01

    Dengue is a mosquito-transmitted viral infection of major international public health concern. Global environmental and socio-economic change has created ideal conditions for the global expansion of dengue transmission. Innovative modelling tools help in understanding the global determinants of dengue risk and the relative impact of environmental and socio-economic factors on dengue transmission and spread. While climatic factors may act as a limiting factor on the global scale, other processes may play a dominant role at the local level. Understanding the spatial scales at which environmental and socio-economic factors dominate can help to target appropriate dengue control and prevention strategies.

  12. Current Status of Dengue Therapeutics Research and Development.

    PubMed

    Low, Jenny G H; Ooi, Eng Eong; Vasudevan, Subhash G

    2017-03-01

    Dengue is a significant global health problem. Even though a vaccine against dengue is now available, which is a notable achievement, its long-term protective efficacy against each of the 4 dengue virus serotypes remains to be definitively determined. Consequently, drugs directed at the viral targets or critical host mechanisms that can be used safely as prophylaxis or treatment to effectively ameliorate disease or reduce disease severity and fatalities are still needed to reduce the burden of dengue. This review will provide a brief account of the status of therapeutics research and development for dengue. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America.

  13. 75 FR 6211 - Prospective Grant of Exclusive License: Purified Inactivated Dengue Tetravalent Vaccine...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-08

    ... Viruses and Chimeric Dengue Viruses''-- European Patent Application Number 02739358.6, filed May 22, 2002... Deletion in the 3'-UTR of Dengue Types 1,2,3, and 4, or Antigenic Chimeric Dengue Viruses 1,2,3, and 4... which enhance the replication of dengue virus type 4 and an antigenic chimeric dengue virus type 2/4...

  14. 78 FR 43219 - Prospective Grant of Exclusive License: Live Attenuated Dengue Tetravalent Vaccine Containing a...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-19

    ... et al., ``Development of Mutations Useful for Attenuating Dengue Viruses and Chimeric Dengue Viruses... Antigenic Chimeric Dengue Viruses 1,2,3, And 4'', United States Patent Application Number 10/970,640 (now...., ``Mutations which enhance the replication of dengue virus type 4 and an antigenic chimeric dengue virus type...

  15. Safety Testing of Dengue-1 and Dengue-3 Seeds for Human Challenges, Unattenuated.

    DTIC Science & Technology

    1987-10-26

    Maryland 21701-5012 ELEMENT NO. NO. 3M1- NO0. CESSION NO. 11. TITLE (Inciude Security Clanafication) 627A 127A80I C E 09 (U) Safety Testing of Dengue -1...and Dengue -3 Seeds for Human Challenges, Unattenuated 12. PERSONAL AUrWOR(S) Potash, Loui.s 13a. TYPE OF REPORT 13b. TIME COVERED 14. DATE OF REPORT...of necessary and identify by block number) FIELD GROUP SUB-GROUP 06 13 ngue-M- Dengue -3; Hepatitis A; Viral seeds; Vaccine no;’-- 03 I 19. ABSTRACI’ 4

  16. Best Practices in Dengue Surveillance: A Report from the Asia-Pacific and Americas Dengue Prevention Boards

    PubMed Central

    Beatty, Mark E.; Stone, Amy; Fitzsimons, David W.; Hanna, Jeffrey N.; Lam, Sai Kit; Vong, Sirenda; Guzman, Maria G.; Mendez-Galvan, Jorge F.; Halstead, Scott B.; Letson, G. William; Kuritsky, Joel; Mahoney, Richard; Margolis, Harold S.

    2010-01-01

    Background Dengue fever is a virus infection that is spread by the Aedes aegypti mosquito and can cause severe disease especially in children. Dengue fever is a major problem in tropical and sub-tropical regions of the world. Methodology/Principal Findings We invited dengue experts from around the world to attend meetings to discuss dengue surveillance. We reviewed literature, heard detailed reports on surveillance programs, and shared expert opinions. Results Presentations by 22 countries were heard during the 2.5 day meetings. We describe the best methods of surveillance in general, the stakeholders in dengue surveillance, and the steps from mosquito bite to reporting of a dengue case to explore how best to carry out dengue surveillance. We also provide details and a comparison of the dengue surveillance programs by the presenting countries. Conclusions/Significance The experts provided recommendations for achieving the best possible data from dengue surveillance accepting the realities of the real world (e.g., limited funding and staff). Their recommendations included: (1) Every dengue endemic country should make reporting of dengue cases to the government mandatory; (2) electronic reporting systems should be developed and used; (3) at minimum dengue surveillance data should include incidence, hospitalization rates, deaths by age group; (4) additional studies should be completed to check the sensitivity of the system; (5) laboratories should share expertise and data; (6) tests that identify dengue virus should be used in patients with fever for four days or less and antibody tests should be used after day 4 to diagnose dengue; and (7) early detection and prediction of dengue outbreaks should be goals for national surveillance systems. PMID:21103381

  17. The Association of Cytokines with Severe Dengue in Children

    PubMed Central

    Mangione, Julia N.A.; Huy, Nguyen Tien; Lan, Nguyen Thi Phuong; Mbanefo, Evaristus Chibunna; Ha, Tran Thi Ngoc; Bao, Lam Quoc; Nga, Cao Thi Phi; Tuong, Vo Van; Dat, Tran Van; Thuy, Tran Thi; Tuan, Ha Manh; Huong, Vu Thi Que; Hirayama, Kenji

    2014-01-01

    Background: Dengue virus infection is a major public health problem. A hypothesis put forward for severe dengue is the cytokine storm, a sudden increase in cytokines that induces vascular permeability. Previous studies and our recent meta-analysis showed that IL-6, IL-8, IFNγ, TNFα, VEGF-A and VCAM-1 are associated with dengue shock syndrome. Therefore, in this study we aim to validate the association of these cytokines with severe dengue. Methods & Findings: In a hospital based-case control study in Vietnam, children with dengue fever, other febrile illness and healthy controls were recruited. Dengue virus infection was confirmed by several diagnostic tests. Multiplex immunoassay using Luminex technology was used to measure cytokines simultaneously. A positive association with dengue shock syndrome was found for VCAM-1, whereas a negative association was found for IFNγ. Furthermore, multivariate logistic analysis also showed that VCAM-1 and IFNγ were independently correlated with dengue shock syndrome. Conclusion: IFNγ and VCAM-1 were associated with dengue shock syndrome, although their role in the severe dengue pathogenesis remains unclear. Additional studies are required to shed further light on the function of these cytokines in severe dengue. PMID:25589878

  18. Estimation of dengue infection for travelers in Thailand.

    PubMed

    Polwiang, Sittisede

    2016-01-01

    Dengue infection among travelers has become one of the most public health concerns in present days. The importation of dengue virus can initiate an outbreak in non-endemic regions. Thailand is one of the countries topping the list of highest dengue infections in travelers. This study estimates the risk of dengue infection among travelers during their visit in Thailand by using a mathematical model with seasonal variations. The risk of dengue infection in high dengue season is 2.50-4.07 times that on low dengue season depending on the locations. The average daily risk of dengue infections of Thailand per 100,000 travelers is 2.14 and 7.03 for low and high dengue season, respectively. The highest rate of infection is Rayong and the lowest rate is Sing Buri. Several popular tourist provinces are high dengue endemic areas. This study provides useful information on dengue infection among travelers. The main factors are the time of arrival in the year, the duration of stay of the travelers and the locations where the travelers spend most of their time. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Diagnosis of Dengue Infection Using Conventional and Biosensor Based Techniques.

    PubMed

    Parkash, Om; Shueb, Rafidah Hanim

    2015-10-19

    Dengue is an arthropod-borne viral disease caused by four antigenically different serotypes of dengue virus. This disease is considered as a major public health concern around the world. Currently, there is no licensed vaccine or antiviral drug available for the prevention and treatment of dengue disease. Moreover, clinical features of dengue are indistinguishable from other infectious diseases such as malaria, chikungunya, rickettsia and leptospira. Therefore, prompt and accurate laboratory diagnostic test is urgently required for disease confirmation and patient triage. The traditional diagnostic techniques for the dengue virus are viral detection in cell culture, serological testing, and RNA amplification using reverse transcriptase PCR. This paper discusses the conventional laboratory methods used for the diagnosis of dengue during the acute and convalescent phase and highlights the advantages and limitations of these routine laboratory tests. Subsequently, the biosensor based assays developed using various transducers for the detection of dengue are also reviewed.

  20. Dengue: the risk to developed and developing countries.

    PubMed Central

    Monath, T P

    1994-01-01

    Dengue viruses are members of the Flaviviridae, transmitted principally in a cycle involving humans and mosquito vectors. In the last 20 years the incidence of dengue fever epidemics has increased and hyperendemic transmission has been established over a geographically expanding area. A severe form, dengue hemorrhagic fever (DHF), is an immunopathologic disease occurring in persons who experience sequential dengue infections. The risk of sequential infections, and consequently the incidence of DHF, has risen dramatically, first in Asia and now in the Americas. At the root of the emergence of dengue as a major health problem are changes in human demography and behavior, leading to unchecked populations of and increased exposure to the principal domestic mosquito vector, Aedes aegypti. Virus-specified factors also influence the epidemiology of dengue. Speculations on future events in the epidemiology, evolution, and biological expression of dengue are presented. Images PMID:8146129

  1. Dengue vaccine: a valuable asset for the future.

    PubMed

    Jindal, Harashish; Bhatt, Bhumika; Malik, Jagbir Singh; S K, Shashikantha

    2014-01-01

    Dengue has emerged as one of the major global public health problems. The disease has broken out of its shell and has spread due to increased international travel and climatic changes. Globally, over 2.5 billion people accounting for >40% of the world's population are at risk from dengue. Since the 1940s, dengue vaccines have been under investigation. A live-attenuated tetravalent vaccine based on chimeric yellow fever-dengue virus (CYD-TDV) has progressed to phase III efficacy studies. Dengue vaccine has been found to be a cost-effective intervention to reduce morbidity and mortality. Current dengue vaccine candidates aim to protect against the 4 dengue serotypes, but the recent discovery of a fifth serotype could complicate vaccine development. In recent years, an urgent need has been felt for a vaccine to prevent the morbidity and mortality from this disease in a cost-effective way.

  2. Vaccines for the prevention of dengue: development update.

    PubMed

    Thomas, Stephen J; Endy, Timothy P

    2011-06-01

    The dengue viruses (DENV) are mosquito-borne flaviviruses which cause a spectrum of clinical disease known as "dengue," and have emerged and re-emerged as a significant global health problem. It is estimated more than 120 countries currently have endemic DENV transmission, 55% of the world's population is at risk of infection, and there are between 70-500 million infections of which 2.1 million are clinically severe resulting in 21,000 deaths annually. By all estimates the global dengue problem will continue to worsen due to the increasing mobility of the population, ecological changes, and the inability to effectively sustain vector control. There are no licensed antivirals or vaccines to treat or prevent dengue. The development and widespread use of a safe and efficacious dengue vaccine is required to significantly reduce the global dengue burden. In this review the authors discuss dengue vaccines currently in the pre-clinical and clinical development pipeline.

  3. Unusual Presentation of Dengue Fever-Cerebral Venous Thrombosis

    PubMed Central

    Vairamon, Pradhosh M; Gowtham, Thiruvengadam; Das, Ashok Kumar

    2015-01-01

    Dengue infection can present as febrile illness with thrombocytopenia, dengue shock syndrome and dengue haemorrhagic fever. Neurological manifestation of dengue infection is more predominant in endemic region. Here, we report a case with unusual neurological presentation of dengue infection. A 16-year-old boy presented with fever for two week duration, headache and double vision involving left eye for two days. He had multiple erythematous rashes all over the body on 3rd day and treated conservatively. On examination he had bilateral papilloedema, left eye restricted abduction. His investigation revealed thrombocytopenia and positive dengue serology. His MRI brain with venogram showed bilateral transverse sinus thrombosis. Hence he was diagnosed as cerebral venous thrombosis due to dehydration with underlying dengue infection. He was hydrated and managed conservatively. On 3rd day his double vision started improving. His repeat MR Venogram was done after two week duration, which revealed recanalisation of bilateral transverse sinus. PMID:26266153

  4. Diagnosis of Dengue Infection Using Conventional and Biosensor Based Techniques

    PubMed Central

    Parkash, Om; Hanim Shueb, Rafidah

    2015-01-01

    Dengue is an arthropod-borne viral disease caused by four antigenically different serotypes of dengue virus. This disease is considered as a major public health concern around the world. Currently, there is no licensed vaccine or antiviral drug available for the prevention and treatment of dengue disease. Moreover, clinical features of dengue are indistinguishable from other infectious diseases such as malaria, chikungunya, rickettsia and leptospira. Therefore, prompt and accurate laboratory diagnostic test is urgently required for disease confirmation and patient triage. The traditional diagnostic techniques for the dengue virus are viral detection in cell culture, serological testing, and RNA amplification using reverse transcriptase PCR. This paper discusses the conventional laboratory methods used for the diagnosis of dengue during the acute and convalescent phase and highlights the advantages and limitations of these routine laboratory tests. Subsequently, the biosensor based assays developed using various transducers for the detection of dengue are also reviewed. PMID:26492265

  5. Clinical and Oral Implications of Dengue Fever: A Review

    PubMed Central

    Roopashri, G; Vaishali, M R; David, Maria Priscilla; Baig, Muqeet; Navneetham, Anuradha; Venkataraghavan, Karthik

    2015-01-01

    Dengue is a viral infection with fatal potential complications. It is also called as break-bone fever. Worldwide dengue infection is the most common mosquito-borne viral disease. It is caused by vector Aedesa egypti and represents a major public health issue in more than 100 tropical countries. The word dengue is obtained from Swahili phrase Ka-dinga pepo meaning “cramplikeseizure.” Dengue viral infections are characterized by abrupt febrile illness, but can also lead to significant morbidity and mortality. Hence, it requires an early and correct diagnosis. Gingival bleeding is the most common oral manifestation of dengue infection. Although oral lesions are uncommon in dengue infections and if manifested, may be mistaken for bleeding disorders. This review emphasizes the significance of oral lesions as it may be the early indicators of dengue hemorrhagic fever. PMID:25859113

  6. [A possible fifth dengue virus serotype].

    PubMed

    da Silva Voorham, Júlia M

    2014-01-01

    Sylvatic dengue viruses are both evolutionarily and ecologically distinguishable from the human dengue virus (DENV). Sporadic episodes of sylvatic human infections in West Africa and Southeast Asia suggest that sylvatic DENV regularly come into contact with human beings. Following a study on the sylvatic transmission cycle in Malaysia in 2007, researchers announced that a new DENV serotype, DENV-5, had been discovered. Scientists are still sceptical about these new findings, and indicate that more data is necessary to determine whether this 'new' virus really is a different serotype or whether it is a variant of one of the four DENV serotypes already known. The good news is that this new variant has not yet established itself in the human transmission cycle. However, if it really is a new serotype this will have implications for the long-term control of dengue using vaccines currently under development.

  7. Impediments of reporting dengue cases in India.

    PubMed

    Das, Sushmita; Sarfraz, Asim; Jaiswal, Nitesh; Das, Pradeep

    2017-03-02

    Dengue has emerged as one of the most important mosquito-borne, fatal flaviviral disease, apparently expanding as a global health problem. An estimated 3.6 billion people are at risk for dengue, with 50 million infections per year occurring across 100 countries globally. The annual number of dengue fever cases in India is many times higher than it is officially reported. This under reporting would play a major role in the government's decision-making. Underestimating of the disease in India encumbers its people from taking preventive measures, discourages efforts to ensnare the sources of the disease and deliberates efforts for vaccine research. In this article, we highlight the probable impediments of under reporting leading to its impact on national and global public health and also offer key remedies to effectively address the issues across the clinics to the community level.

  8. Dengue Virus Evolution and Virulence Models

    PubMed Central

    Rico-Hesse, Rebeca

    2008-01-01

    Dengue virus transmission has increased dramatically in the past 2 decades, making this virus one of the most important mosquito-borne human pathogens. The emergence of dengue hemorrhagic fever in most tropical countries has made its control a public health priority, but no vaccines or treatments exist. Little is understood about dengue virus pathogenesis, because no other animals develop symptoms of disease, and research, therefore, has been limited to studies involving patients. Although epidemiologic and evolutionary studies have pointed to host and viral factors in determining disease outcome, only recently developed models could prove the importance of viral genotypes in causing severe epidemics. The influence of host immune status and mosquito vectorial capacity are also being tested in mathematical models to determine virus population dynamics. Therefore, new technologies are allowing us to better understand how specific virus variants cause more disease than others, and these virus variants should be targeted for detection, control, and treatment. PMID:17479944

  9. Optimal Repellent Usage to Combat Dengue Fever.

    PubMed

    Dorsett, Chasity; Oh, Hyunju; Paulemond, Marie Laura; Rychtář, Jan

    2016-05-01

    Dengue fever is one of the most important vector-borne diseases. It is transmitted by Aedes Stegomyia aegypti, and one of the most effective strategies to combat the disease is the reduction of exposure to bites of these mosquitoes. In this paper, we present a game-theoretical model in which individuals choose their own level of protection against mosquito bites in order to maximize their own benefits, effectively balancing the cost of protection and the risk of contracting the dengue fever. We find that even when the usage of protection is strictly voluntary, as soon as the cost of protection is about 10,000 times less than the cost of contracting dengue fever, the optimal level of protection will be within 5 % of the level needed for herd immunity.

  10. Hepatitis and thrombocytopenia: markers of dengue mortality.

    PubMed

    Krishnamoorthy, Smitha; Bhatt, Arun N; Mathew, Celine Thalappillil; Ittyachen, Abraham M

    2017-04-01

    Dengue fever is of great concern to public health in India as it contributes significantly to the burden of healthcare. The aim of our study was to measure mortality in dengue and its association with hepatitis and thrombocytopenia. Our study was performed in a tertiary care setting in the state of Kerala in southern India. Adult patients admitted in the year 2013 were included. Among 1308 confirmed dengue patients, the mortality rate was 1.76%. Hepatitis and thrombocytopenia were present in over 80% of all patients, but severe hepatitis was seen in 11.4% and severe thrombocytopenia in 9.3%. These were markers of fatal outcome. Other factors significantly associated with mortality were age >60 years, male sex, diabetes and the presence of any co-morbidity.

  11. [Imported dengue: an emerging arbovirosis in Spain].

    PubMed

    Ramos Geldres, T T; García López-Hortelano, M; Baquero-Artigao, F; Montero Vega, D; López Quintana, B; Mellado Peña, M J

    2015-01-01

    Dengue is caused by one of 4 serotypes of dengue virus. Only imported cases have been reported in Spain. The main clinical findings are fever and exanthema, although there may be severe forms, particularly in secondary infections. Five children with a primary, non severe dengue infection are presented. The diagnosis was based on clinical suspicion and epidemiological history, and confirmed by immunochromatography and ELISA tests. The outcome was favourable in all cases. It is important to consider this diagnosis in international travellers that present with fever within the 14 days of returning from an endemic area, in order to get an early diagnosis, adequate treatment and a good prognosis. Copyright © 2014 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

  12. Dengue vaccines: challenges, development, current status and prospects.

    PubMed

    Ghosh, A; Dar, L

    2015-01-01

    Infection with dengue virus (DENV) is the most rapidly spreading mosquito-borne viral disease in the world. The clinical spectrum of dengue, caused by any of the four serotypes of DENV, ranges from mild self-limiting dengue fever to severe dengue, in the form dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Increased rates of hospitalization due to severe dengue, during outbreaks, result in massive economic losses and strained health services. In the absence of specific antiviral therapy, control of transmission of DENV by vector management is the sole method available for decreasing dengue-associated morbidity. Since vector control strategies alone have not been able to satisfactorily achieve reduction in viral transmission, the implementation of a safe, efficacious and cost-effective dengue vaccine as a supplementary measure is a high public health priority. However, the unique and complex immunopathology of dengue has complicated vaccine development. Dengue vaccines have also been challenged by critical issues like lack of animal models for the disease and absence of suitable markers of protective immunity. Although no licensed dengue vaccine is yet available, several vaccine candidates are under phases of development, including live attenuated virus vaccines, live chimeric virus vaccines, inactivated virus vaccines, subunit vaccines, DNA vaccines and viral-vectored vaccines. Although some vaccine candidates have progressed from animal trials to phase II and III in humans, a number of issues regarding implementation of dengue vaccine in countries like India still need to be addressed. Despite the current limitations, collaborative effects of regulatory bodies like World Health Organization with vaccine manufacturers and policy makers, to facilitate vaccine development and standardize field trials can make a safe and efficacious dengue vaccine a reality in near future.

  13. Research on Climate and Dengue in Malaysia: A Systematic Review.

    PubMed

    Hii, Yien Ling; Zaki, Rafdzah Ahmad; Aghamohammadi, Nasrin; Rocklöv, Joacim

    2016-03-01

    Dengue is a climate-sensitive infectious disease. Climate-based dengue early warning may be a simple, low-cost, and effective tool for enhancing surveillance and control. Scientific studies on climate and dengue in local context form the basis for advancing the development of a climate-based early warning system. This study aims to review the current status of scientific studies in climate and dengue and the prospect or challenges of such research on a climate-based dengue early warning system in a dengue-endemic country, taking Malaysia as a case study. We reviewed the relationship between climate and dengue derived from statistical modeling, laboratory tests, and field studies. We searched electronic databases including PubMed, Scopus, EBSCO (MEDLINE), Web of Science, and the World Health Organization publications, and assessed climate factors and their influence on dengue cases, mosquitoes, and virus and recent development in the field of climate and dengue. Few studies in Malaysia have emphasized the relationship between climate and dengue. Climatic factors such as temperature, rainfall, and humidity are associated with dengue; however, these relationships were not consistent. Climate change projections for Malaysia show a mounting risk for dengue in the future. Scientific studies on climate and dengue enhance dengue surveillance in the long run. It is essential for institutions in Malaysia to promote research on climate and vector-borne diseases to advance the development of climate-based early warning systems. Together, effective strategies that improve existing research capacity, maximize the use of limited resources, and promote local-international partnership are crucial for sustaining research on climate and health.

  14. Cost of dengue outbreaks: literature review and country case studies

    PubMed Central

    2013-01-01

    Background Dengue disease surveillance and vector surveillance are presumed to detect dengue outbreaks at an early stage and to save – through early response activities – resources, and reduce the social and economic impact of outbreaks on individuals, health systems and economies. The aim of this study is to unveil evidence on the cost of dengue outbreaks. Methods Economic evidence on dengue outbreaks was gathered by conducting a literature review and collecting information on the costs of recent dengue outbreaks in 4 countries: Peru, Dominican Republic, Vietnam, and Indonesia. The literature review distinguished between costs of dengue illness including cost of dengue outbreaks, cost of interventions and cost-effectiveness of interventions. Results Seventeen publications on cost of dengue showed a large range of costs from 0.2 Million US$ in Venezuela to 135.2 Million US$ in Brazil. However, these figures were not standardized to make them comparable. Furthermore, dengue outbreak costs are calculated differently across the publications, and cost of dengue illness is used interchangeably with cost of dengue outbreaks. Only one paper from Australia analysed the resources saved through active dengue surveillance. Costs of vector control interventions have been reported in 4 studies, indicating that the costs of such interventions are lower than those of actual outbreaks. Nine papers focussed on the cost-effectiveness of dengue vaccines or dengue vector control; they do not provide any direct information on cost of dengue outbreaks, but their modelling methodologies could guide future research on cost-effectiveness of national surveillance systems. The country case studies – conducted in very different geographic and health system settings - unveiled rough estimates for 2011 outbreak costs of: 12 million US$ in Vietnam, 6.75 million US$ in Indonesia, 4.5 million US$ in Peru and 2.8 million US$ in Dominican Republic (all in 2012 US$). The proportions of the

  15. Understanding dengue pathogenesis: implications for vaccine design.

    PubMed Central

    Stephenson, John R.

    2005-01-01

    In the second half of the twentieth century dengue spread throughout the tropics, threatening the health of a third of the world's population. Dengue viruses cause 50-100 million cases of acute febrile disease every year, including more than 500,000 reported cases of the severe forms of the disease--dengue haemorrhagic fever and dengue shock syndrome. Attempts to create conventional vaccines have been hampered by the lack of suitable experimental models, the need to provide protection against all four serotypes simultaneously and the possible involvement of virus-specific immune responses in severe disease. The current understanding of dengue pathogenesis is outlined in this review, with special emphasis on the role of the immune response. The suspected involvement of the immune system in increased disease severity and vascular damage has raised concerns about every vaccine design strategy proposed so far. Clearly more research is needed on understanding the correlates of protection and mechanisms of pathogenesis. There is, however, an urgent need to provide a solution to the escalating global public health problems caused by dengue infections. Better disease management, vector control and improved public health measures will help reduce the current disease burden, but a safe and effective vaccine is probably the only long-term solution. Although concerns have been raised about the possible safety and efficacy of both conventional and novel vaccine technologies, the situation is now so acute that it is not possible to wait for the perfect vaccine. Consequently the careful and thorough evaluation of several of the current candidate vaccines may be the best approach to halting the spread of disease. PMID:15868023

  16. [Epidemiological dynamics of Dengue on Easter Island].

    PubMed

    Canals, Mauricio; González, Christian; Canals, Andrea; Figueroa, Daniela

    2012-08-01

    Dengue is considered an emerging disease with an increasing prevalence especially in South America. In 2002, an epidemic of classic Dengue (DENV-1) occurred unexpectedly on Easter Island, where it had never been detected before. It reappeared in 2006-2007 and 2008, 2009 and 2011. The aim of this study was to estimate the most relevant parameters of the epidemiological dynamics of transmission of Dengue on Easter Island and to model the dynamics since 2002, comparing the predictions with the actual situation observed. Of the total cases, 52.27% were females and 47.73% men. The average age of infection was 31.38 ± 18.37 years, similar in men and women. We estimated the reproductive number R0 = 3.005 with an IC0,95 = [1.92, 4.61]. The inter-epidemic period reached an estimated T = 5.20 to 6.8 years. The case simulation showed recurrent epidemics with decreasing magnitude (damped oscillations), which is a known phenomenon in models of dengue and malaria. There was good qualitative fit to the epidemiological dynamics from 2002 onwards. It accurately predicted the rise in cases between 2006 and 2011. The predicted number of cases during the 2002 epidemic is greater than the confirmed cases and the predicted epidemic was faster than notified cases. Interepidemic period in the simulation was 6.72 years between 2002 and 2008 and 4.68 years between 2008 and 2013. From the theoretical perspective, the first epidemic had affected 94% of the population (approximately 3500 cases), but 639 were reported suggesting underreporting and a lot of sub-clinical cases occurred. Future epidemic of decreasing size are expected, although the main danger are epidemics of hemorrhagic dengue fever resulting from the introduction of different dengue virus serotypes.

  17. Sensorineural hearing loss in hemorrhagic dengue?

    PubMed Central

    Ribeiro, Bruna Natália Freire; Guimarães, Alexandre Caixeta; Yazawa, Felipe; Takara, Tammy Fumiko Messias; de Carvalho, Guilherme Machado; Zappelini, Carlos Eduardo Monteiro

    2014-01-01

    Introduction Dengue is an acute febrile infectious disease, with high fever followed by symptoms flu-like. Dengue hemorrhagic fever (DHF) is a vascular leak syndrome and could present spontaneous bleeding and worsening of symptoms after some days. Dengue could have some ENT manifestations, however hearing loss is not one of them. Sudden hearing loss is considered as sensorineural or perceptual hearing loss with a sudden onset in a person without other prior otological history. The relation between infectious diseases and sudden hearing are been investigated, some viruses were already linked, but the relation between dengue virus and sudden hearing still remains unknown. This article has the goal of presenting a case of DHF that evolved with SSHL in his hospitalization process. Presentation of case We report a 60 years-male patient of with DHF who developed bilateral secretory otitis media and sensorineural hearing loss after the fifth day of onset of symptoms. His hearing loss remained even after 7 months and the patient was referred for hearing aid fitting. Discussion and conclusion This is the first case report that brings together DHF and sudden hearing loss. In the development of this case no other cause to sudden hearing loss was found and the correlation between dengue and hearing loss was questioned. In the literature review was found that some viruses, as mumps virus, varicella-zoster virus and HSV-1 and HSV-2 are related to sudden hearing loss, all of them fit in the viral theory. Besides the viral theory of sudden hearing loss, there is the vascular theory that is the occlusion of the end artery that supplies the cochlea. DHF has a vascular commitment, and the hypothesis of a vascular cause could be elicited in this case. Many studies in this area are needed and this article has the objective of elicit the discussion about the subject. Could dengue be associated with sensorineural hearing loss? PMID:25625489

  18. T cell responses and dengue haemorrhagic fever.

    PubMed

    Screaton, Gavin; Mongkolsapaya, Juthathip

    2006-01-01

    The enhancement of severe disease upon secondary infection makes dengue almost unique among infectious pathogens and presents a serious challenge to vaccine design. Several key observations have been made which shed light onto this phenomenon particularly that antibodies can enhance Fc receptor-dependent uptake of virus into macrophages thereby increasing virus replication. Furthermore there seems to be a relationship between the peak virus load and disease severity. However, a second key feature of dengue is that the life-threatening symptoms do not correlate with the period of high viraemia; instead they occur at a time when the virus load is in steep decline. The coincidence of severe disease manifestations with defervescence and virus control suggests that the symptoms may be a consequence of the immune response to the virus rather than virus induced cytopathology. One of the key elements in the immune response to viruses are T cells which can both secrete a host of inflammatory cytokines and also be directly cytotoxic to infected cells. There are a number of experimental models of T cell-induced immunopathology including in responses to viruses. Particularly interesting in this respect are models of RSV-induced immunopathology, which have direct relevance to vaccine design as a formalin-inactivated vaccine to RSV actually enhanced disease in children when they became naturally infected with RSV, an echo of the disease enhancement seen in dengue. We will present an analysis of CD8+ T cell responses to a number of novel T cell epitopes during dengue infection and also analyse the function and cytokine secretion of these cells. We suggest that an exaggerated and partially misdirected T cell response seen in secondary dengue infection may be part of the complex series of events leading to dengue haemorrhagic fever and shock.

  19. Cost-effectiveness of dengue vaccination in Yucatán, Mexico using a dynamic dengue transmission model.

    PubMed

    Shim, Eunha

    2017-01-01

    The incidence of dengue fever (DF) is steadily increasing in Mexico, burdening health systems with consequent morbidities and mortalities. On December 9th, 2015, Mexico became the first country for which the dengue vaccine was approved for use. In anticipation of a vaccine rollout, analysis of the cost-effectiveness of the dengue vaccination program that quantifies the dynamics of disease transmission is essential. We developed a dynamic transmission model of dengue in Yucatán, Mexico and its proposed vaccination program to incorporate herd immunity into our analysis of cost-effectiveness analysis. Our model also incorporates important characteristics of dengue epidemiology, such as clinical cross-immunity and susceptibility enhancement upon secondary infection. Using our model, we evaluated the cost-effectiveness and economic impact of an imperfect dengue vaccine in Yucatán, Mexico. Our study indicates that a dengue vaccination program would prevent 90% of cases of symptomatic DF incidence as well as 90% of dengue hemorrhagic fever (DHF) incidence and dengue-related deaths annually. We conclude that a dengue vaccine program in Yucatán, Mexico would be very cost-effective as long as the vaccination cost per individual is less than $140 and $214 from health care and societal perspectives, respectively. Furthermore, at an exemplary vaccination cost of $250 USD per individual on average, dengue vaccination is likely to be cost-effective 43% and 88% of the time from health care and societal perspectives, respectively.

  20. Pathogenesis of Dengue Vaccine Viruses in Mosquitoes.

    DTIC Science & Technology

    1984-01-01

    type 2 (Price, 1973), and attenuated Japanese encephalitis vaccine virus (Chen and Beaty, 1982). Sabin (1948) showed that attenuated dengue virus...M194 992 PATHOGENESIS OF DENGUJE VACCINE VIRUSES IN NOSSUITOES vi1 (u) COLORADO STATE UNIV FORT COLLINS DEPT OF MICROBIOLOGY AND ENVIRONMENTAL...IW AV wWW W N A A~~ Nq .. mcFILE COPY 0)0 AD PATHOGENESIS OF DENGUE VACCINE VIRUSES IN MOSQUITOES Annual Report Barry J. Beaty, Ph.D. D T IC ELECTE

  1. Why are people with dengue dying? A scoping review of determinants for dengue mortality.

    PubMed

    Carabali, Mabel; Hernandez, Libia Milena; Arauz, Maria Jose; Villar, Luis Angel; Ridde, Valéry

    2015-07-30

    Dengue is a viral disease whose clinical spectrum ranges from unapparent to severe forms and fatal outcomes. Although dengue death is 99% avoidable, every year around 20,000 deaths are estimated to occur in more than 100 countries. We consider that, along with biological factors, social determinants of health (SDHs) are related to dengue deaths as well. A scoping review was conducted to explore what has been written about the role of SDHs in dengue mortality. The inclusion criteria were that documents (grey or peer-reviewed) had to include information about dengue fatal cases in humans and be published between 1997 and 2013 and written in English, Spanish, Portuguese or French. The search was conducted using a set of key words related to dengue mortality in several electronic databases: PubMed, LILACS, COCHRANE, Scielo, Science Direct, WHOLIS, OpenGrey, OpenSingle and Google Scholar. Information on SDHs was categorized under individual, social and environmental, and health systems dimensions. A summative content analysis using QDA Miner was conducted to assess the frequency of information on SDHs and its contextual meaning in the reviewed literature. The role of each SDH in dengue mortality was assessed using content analysis results. From a total of 971 documents retrieved, 78 met the criteria. Those documents were published in the Americas region (50.0%), Asia (38.4%), Europe (9.0%) and Africa (2.6%). The described SDHs related to dengue deaths included, in the individual dimension: age, ethnicity, education, type of infection and immunological status; and in the social dimension: poverty and care-seeking behavior. The health systems dimension included access, opportunity, and quality of care, as well as health staff knowledge. Ethnicity was considered a determinant that depends on cultural and socioeconomic conditions. Along with biological factors, there are several SDHs related to dengue mortality. However, only a few of these have been systematically analyzed

  2. Characterization of the 2013 dengue epidemic in Myanmar with dengue virus 1 as the dominant serotype.

    PubMed

    Ngwe Tun, Mya Myat; Kyaw, Aung Kyaw; Makki, Nader; Muthugala, Rohitha; Nabeshima, Takeshi; Inoue, Shingo; Hayasaka, Daisuke; Moi, Meng Ling; Buerano, Corazon C; Thwe, Saw Myat; Thant, Kyaw Zin; Morita, Kouichi

    2016-09-01

    In 2013 in Myanmar, dengue epidemic occurred with 20,255 cases including 84 deaths. This study aimed to determine the serological and molecular characteristics of dengue virus (DENV) infection among children with clinical diagnosis of dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS) during this period. Single acute serum samples were collected from 300 children in Mandalay Children Hospital, Mandalay, Myanmar. Out of the 300 children, 175 (58.3%) and 183 (61%) were positive for anti-dengue IgM and anti-dengue IgG, respectively. Among the IgM positives, 41 (23.4%) had primary DENV infection. Thirty-nine DENV strains (23 DENV-1, 10 DENV-2 and 6 DENV-4) were successfully isolated after inoculation of the patient serum samples onto C6/36 cells. DENV 1 was the dominant serotype in the 2013 epidemic. There was no correlation between the infecting serotypes and clinical severities. The DENV-1 strains belonged to three lineages of the genotype 1; the DENV-2 strains were of the Asian I genotype and were separated into two lineages; and DENV-4 strains belonged to the same lineage of genotype I. It is of interest to note the diversity of DENV-1 and -2 circulating in the same location during June-August 2013. These DENV isolates were genetically close (98%-100%) to the other previously reported isolates from Myanmar and its neighboring countries, namely China, Thailand, Sri Lanka, Cambodia and Vietnam. Primary DENV infection was still high among the severe dengue cases. Different serotypes of DENV were co-circulating in 2013, however, genotype shift was not observed. Additionally, amino acid mutations were detected in the study strains not seen in the previously reported strains from other countries and Myanmar. This paper provided information on the circulating serotypes for the last 15years and the recent dengue situation in Mandalay, Myanmar after 2006. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Complete Genome Sequence of a Dengue Virus Serotype 4 Strain Isolated in Roraima, Brazil

    PubMed Central

    Souza, Victor C.; Silva, George A. V.; Maito, Rodrigo M.; Granja, Fabiana; Siqueira, Thalita; Acosta, Pablo O. A.

    2012-01-01

    Dengue is the most important arboviral disease worldwide. We report the complete genome sequence of a dengue virus serotype 4, genotype II strain isolated in 2010 from a patient with classical dengue fever in Boa Vista, Roraima, Brazil. PMID:22247521

  4. Serological characterization of dengue virus infections observed among dengue hemorrhagic fever/dengue shock syndrome cases in upper Myanmar.

    PubMed

    Ngwe Tun, Mya Myat; Thant, Kyaw Zin; Inoue, Shingo; Kurosawa, Yae; Lwin, Yee Yee; Lin, Sanda; Aye, Kay Thi; Thet Khin, Pe; Myint, Tin; Htwe, Khin; Mapua, Cynthia A; Natividad, Filipinas F; Hirayama, Kenji; Morita, Kouichi

    2013-07-01

    In Myanmar, dengue fever (DF)/dengue hemorrhagic fever (DHF) is one of the leading causes of morbidity and mortality among children. From Pyinmana Hospital in 2004 and Mandalay Children Hospital in 2006, 160 patients diagnosed clinically to have DHF/dengue shock syndrome (DSS) were examined for immunoglobulin M (IgM) and IgG levels. A focus reduction neutralization test was also used to determine primary or secondary dengue virus (DENV) infection. By using IgM-capture ELISA, 139 cases were confirmed as DENV infections. Of these IgM-positives, 94 samples were collected 7-24 days from the onset of illness, to which 13 (14%) and 81 (86%) were determined to be primary and secondary DENV infections, respectively. The 13 primary DENV infection cases were spread among the various severity groups (DHF grade I-IV and DSS) and represented age groups ranging from <1 year of age to 9 years of age. The patients in these primary infection cases showed a remarkably high IgM with a low IgG titer response compared with the secondary infection cases. No significant differences were observed in IgG titers with clinical severity. The data obtained in this study suggest that primary DENV infection cases exist certainly among DHF/DSS cases in Myanmar, and that additional mechanism(s) aside from the antibody-dependent enhancement mechanism could have influenced the clinical severity in DHF/DSS cases.

  5. DengueME: A Tool for the Modeling and Simulation of Dengue Spatiotemporal Dynamics †

    PubMed Central

    de Lima, Tiago França Melo; Lana, Raquel Martins; de Senna Carneiro, Tiago Garcia; Codeço, Cláudia Torres; Machado, Gabriel Souza; Ferreira, Lucas Saraiva; de Castro Medeiros, Líliam César; Davis Junior, Clodoveu Augusto

    2016-01-01

    The prevention and control of dengue are great public health challenges for many countries, particularly since 2015, as other arboviruses have been observed to interact significantly with dengue virus. Different approaches and methodologies have been proposed and discussed by the research community. An important tool widely used is modeling and simulation, which help us to understand epidemic dynamics and create scenarios to support planning and decision making processes. With this aim, we proposed and developed DengueME, a collaborative open source platform to simulate dengue disease and its vector’s dynamics. It supports compartmental and individual-based models, implemented over a GIS database, that represent Aedes aegypti population dynamics, human demography, human mobility, urban landscape and dengue transmission mediated by human and mosquito encounters. A user-friendly graphical interface was developed to facilitate model configuration and data input, and a library of models was developed to support teaching-learning activities. DengueME was applied in study cases and evaluated by specialists. Other improvements will be made in future work, to enhance its extensibility and usability. PMID:27649226

  6. [Dengue virus serotype 1 (DENV-1) from Colombia: its contribution to dengue occurrence in Santander].

    PubMed

    Ocazionez-Jiménez, Raquel E; Ortiz-Báez, Ayda Susana; Gómez-Rangel, Sergio Yebrail; Miranda-Esquivel, Daniel R

    2013-09-01

    Between 1998 and 2008 all dengue virus serotypes circulated in the Departamento de Santander, an endemic region in northeastern Colombia. No information is available as to the role of serotype 1 (DENV-1) with respect to epidemiology of dengue. To analyze the relationship between changes in DENV-1 predominance with respect to genetic diversity, prevalence of others serotypes and occurrence of severe dengue. Virus genetic diversity was studied by phylogenetic analysis comparing E gene sequences from 12 viral strains. Data about serotypes predominance obtained in previous studies and official data about dengue incidence were used for analysis. Selected viruses grouped into genotype V together DENV-1 from Latin America countries, and segregation in four lineages was evidenced. Changes in virus predominance coincided with replacement of lineage, increase in prevalence of DENV-2 and DENV-3 and increase of severe dengue. Genetic divergence could have contributed to changes in DENV-1 predominance. The relationship of the virus with DENV-2 and DENV-3 could create scenarios that promote occurrence of severe cases. More studies are required to ascertain the precise role of serotypes in the epidemiology of dengue.

  7. DengueME: A Tool for the Modeling and Simulation of Dengue Spatiotemporal Dynamics.

    PubMed

    de Lima, Tiago França Melo; Lana, Raquel Martins; de Senna Carneiro, Tiago Garcia; Codeço, Cláudia Torres; Machado, Gabriel Souza; Ferreira, Lucas Saraiva; de Castro Medeiros, Líliam César; Davis Junior, Clodoveu Augusto

    2016-09-15

    The prevention and control of dengue are great public health challenges for many countries, particularly since 2015, as other arboviruses have been observed to interact significantly with dengue virus. Different approaches and methodologies have been proposed and discussed by the research community. An important tool widely used is modeling and simulation, which help us to understand epidemic dynamics and create scenarios to support planning and decision making processes. With this aim, we proposed and developed DengueME, a collaborative open source platform to simulate dengue disease and its vector's dynamics. It supports compartmental and individual-based models, implemented over a GIS database, that represent Aedes aegypti population dynamics, human demography, human mobility, urban landscape and dengue transmission mediated by human and mosquito encounters. A user-friendly graphical interface was developed to facilitate model configuration and data input, and a library of models was developed to support teaching-learning activities. DengueME was applied in study cases and evaluated by specialists. Other improvements will be made in future work, to enhance its extensibility and usability.

  8. Una guia a los padres acerca del sistema educacional = A Parent's Guide to Education. Spanish Edition.

    ERIC Educational Resources Information Center

    Rowch, Nancy

    A guide for Spanish-speaking parents of elementary and secondary school students in Nebraska provides in Spanish, and then in English, information concerning education in the state. Topics covered include: state policy concerning enrolling children in school, medical requirements for enrollment and attendance, the school curriculum requirements…

  9. Una guia a los padres acerca del sistema educacional = A Parent's Guide to Education. Spanish Edition.

    ERIC Educational Resources Information Center

    Rowch, Nancy

    A guide for Spanish-speaking parents of elementary and secondary school students in Nebraska provides in Spanish, and then in English, information concerning education in the state. Topics covered include: state policy concerning enrolling children in school, medical requirements for enrollment and attendance, the school curriculum requirements…

  10. Postmortem Diagnosis of Dengue as an Epidemiological Surveillance Tool

    PubMed Central

    de Góes Cavalcanti, Luciano Pamplona; Nunes de Melo Braga, Deborah; Maria Alexandre da Silva, Lívia; Gondim Aguiar, Marina; Castiglioni, Mariana; Silva-Junior, José Udevanier; Montenegro de Carvalho Araújo, Fernanda; Allana da Costa Pereira, Renata; Malta, Danielle Lima; Pompeu, Margarida Maria de Lima

    2016-01-01

    Dengue remains a problem in Brazil, and a substantial number of cases that progress to death are not diagnosed by health services. We evaluated the impact of a protocol adopted by the Coroner's Office Rocha Furtado (CO-RF) for the detection of unreported deaths from dengue in Brazil. We evaluated prospectively cases of deaths referred to the CO-RF with suspicion of dengue and those referred with other diagnosis in which the pathologists suspected dengue as the cause of death. Biological material was collected from all bodies autopsied, for which the suspected cause of death was dengue, between January 2011 and December 2012. Of the 214 bodies autopsied, 134 (62.6%) tested positive for dengue; of these cases, 121 were classified as dengue according to the World Health Organization's case definition (1997 or 2009, as appropriate). Thus, CO-RF detected 90 deaths from dengue, which were not suspected during disease progression. This CO-RF protocol, through a combined effort of the surveillance and laboratory teams, increased the detection of fatal dengue cases by 5-fold. This is the largest series of autopsies performed in cases of death related to dengue in the world to date. PMID:26598561

  11. Cost of Dengue Vector Control Activities in Malaysia

    PubMed Central

    Packierisamy, P. Raviwharmman; Ng, Chiu-Wan; Dahlui, Maznah; Inbaraj, Jonathan; Balan, Venugopalan K.; Halasa, Yara A.; Shepard, Donald S.

    2015-01-01

    Dengue fever, an arbovirus disease transmitted by Aedes mosquitoes, has recently spread rapidly, especially in the tropical countries of the Americas and Asia-Pacific regions. It is endemic in Malaysia, with an annual average of 37,937 reported dengue cases from 2007 to 2012. This study measured the overall economic impact of dengue in Malaysia, and estimated the costs of dengue prevention. In 2010, Malaysia spent US$73.5 million or 0.03% of the country's GDP on its National Dengue Vector Control Program. This spending represented US$1,591 per reported dengue case and US$2.68 per capita population. Most (92.2%) of this spending occurred in districts, primarily for fogging. A previous paper estimated the annual cost of dengue illness in the country at US$102.2 million. Thus, the inclusion of preventive activities increases the substantial estimated cost of dengue to US$175.7 million, or 72% above illness costs alone. If innovative technologies for dengue vector control prove efficacious, and a dengue vaccine was introduced, substantial existing spending could be rechanneled to fund them. PMID:26416116

  12. Internal travel and risk of dengue transmission in Colombia.

    PubMed

    Chaparro, Pablo E; de la Hoz, Fernando; Lozano Becerra, Juan C; Repetto, Silvia A; Alba Soto, Catalina D

    2014-09-01

    Human behavior plays a key role in the dynamics of dengue transmission. However, research on the relationship between human movement and dengue transmission within endemic countries is limited. From January 2008 to December 2011, the authors of this study conducted a retrospective analysis of imported dengue infections in Bogotá, Colombia. Bogotá is a vector-transmission-free city that is also the capital district and most populated municipality in Colombia. The study revealed that 1) Bogotá inhabitants acquired dengue infection in diverse localities throughout the country but the largest proportion of cases (35.6%) were contracted at popular tourist destinations in dengue-endemic areas near Bogotá (<200-km radius from city limits), and 2) the number of imported dengue cases increased after major holidays, a transmission pattern not seen in dengue-endemic areas, where disease incidence correlates with rainy periods. It is therefore recommended that physicians consider the effect of travel when diagnosing their patients' illnesses, especially outside dengue-endemic areas where diagnosis of the disease can be challenging due to its nonspecific symptoms. The study also showed that analysis of dengue cases imported to regions free of vector transmission can generate an evidence-based model for characterizing the impact of human movement on the spread of diseases like dengue in countries where they are endemic.

  13. An innovative forecasting and dashboard system for Malaysian dengue trends

    NASA Astrophysics Data System (ADS)

    Jamil, Jastini Mohd; Shaharanee, Izwan Nizal Mohd

    2016-08-01

    Dengue fever has been recognized in over 100 countries and 2.5 billion people live in areas where dengue is endemic. It is currently a serious arthropod-borne disease, affecting around 50-100 million people worldwide every year. Dengue fever is also prevalent in Malaysia with numerous cases including mortality recorded over the past year. In 2012, a total of 21,900 cases of dengue fever were reported with 35 deaths. Dengue, a mosquito-transmitted virus, causes a high fever accompanied by significant pain in afflicted patient and the Aedes Aegypti mosquito is the primary disease carrier. Knowing the dangerous effect of dengue fever, thus one of the solutions is to implement an innovative forecasting and dashboard system of dengue spread in Malaysia, with emphasize on an early prediction of dengue outbreak. Specifically, the model developed will provide with a valuable insight into strategically managing and controlling the future dengue epidemic. Importantly, this research will deliver the message to health policy makers such as The Ministry of Health Malaysia (MOH), practitioners, and researchers of the importance to integrate their collaboration in exploring the potential strategies in order to reduce the future burden of the increase in dengue transmission cases in Malaysia.

  14. Cost of Dengue Vector Control Activities in Malaysia.

    PubMed

    Packierisamy, P Raviwharmman; Ng, Chiu-Wan; Dahlui, Maznah; Inbaraj, Jonathan; Balan, Venugopalan K; Halasa, Yara A; Shepard, Donald S

    2015-11-01

    Dengue fever, an arbovirus disease transmitted by Aedes mosquitoes, has recently spread rapidly, especially in the tropical countries of the Americas and Asia-Pacific regions. It is endemic in Malaysia, with an annual average of 37,937 reported dengue cases from 2007 to 2012. This study measured the overall economic impact of dengue in Malaysia, and estimated the costs of dengue prevention. In 2010, Malaysia spent US$73.5 million or 0.03% of the country's GDP on its National Dengue Vector Control Program. This spending represented US$1,591 per reported dengue case and US$2.68 per capita population. Most (92.2%) of this spending occurred in districts, primarily for fogging. A previous paper estimated the annual cost of dengue illness in the country at US$102.2 million. Thus, the inclusion of preventive activities increases the substantial estimated cost of dengue to US$175.7 million, or 72% above illness costs alone. If innovative technologies for dengue vector control prove efficacious, and a dengue vaccine was introduced, substantial existing spending could be rechanneled to fund them. © The American Society of Tropical Medicine and Hygiene.

  15. The prevention and control of dengue after Typhoon Haiyan

    PubMed Central

    Aumentado, Charito; Cerro, Boyd Roderick; Olobia, Leonido; Suy, Lyndon Lee; Reyes, Aldrin; Kusumawathie, Pahalagedera HD; Sagrado, Maria; Hall, Julie Lyn; Abeyasinghe, Rabindra; Foxwell, Alice Ruth

    2015-01-01

    Objective Many of the areas in the Philippines affected by Typhoon Haiyan are endemic for dengue; therefore, dengue prevention was a priority in the initial post-disaster risk assessment. We describe the dengue prevention and response strategies applied after Haiyan. Methods The dengue response was implemented by a wide range of national and international stakeholders. Priorities included the rapid re-establishment of an effective surveillance system to quickly identify new dengue cases, monitor trends and determine the geographical distribution of cases. Dengue rapid diagnostic tests (RDTs) were distributed to sentinel health facilities, and comprehensive vector control activities and entomological surveys were implemented. Several training sessions for key stakeholders and awareness campaigns for communities were organized. Results There were RDT-positive dengue cases reported from urban and semi-urban areas where entomological surveys also confirmed a high density of Aedes aegypti mosquitoes. Although there was an increase in dengue cases in January 2014, the number of cases remained below the epidemic threshold throughout the remaining months of 2014. Discussion There was no large outbreak of dengue after Haiyan, possibly due to the targeted, multifaceted and rapid response for dengue after Haiyan. However, surveillance differed after Typhoon Haiyan, making comparisons with previous years difficult. Multiple players contributed to the response that was also facilitated by close communication and coordination within the Health Cluster. PMID:26767138

  16. The prevention and control of dengue after Typhoon Haiyan.

    PubMed

    Aumentado, Charito; Cerro, Boyd Roderick; Olobia, Leonido; Suy, Lyndon Lee; Reyes, Aldrin; Kusumawathie, Pahalagedera H D; Sagrado, Maria; Hall, Julie Lyn; Abeyasinghe, Rabindra; Foxwell, Alice Ruth; Vestergaard, Lasse S

    2015-01-01

    Many of the areas in the Philippines affected by Typhoon Haiyan are endemic for dengue; therefore, dengue prevention was a priority in the initial post-disaster risk assessment. We describe the dengue prevention and response strategies applied after Haiyan. The dengue response was implemented by a wide range of national and international stakeholders. Priorities included the rapid re-establishment of an effective surveillance system to quickly identify new dengue cases, monitor trends and determine the geographical distribution of cases. Dengue rapid diagnostic tests (RDTs) were distributed to sentinel health facilities, and comprehensive vector control activities and entomological surveys were implemented. Several training sessions for key stakeholders and awareness campaigns for communities were organized. There were RDT-positive dengue cases reported from urban and semi-urban areas where entomological surveys also confirmed a high density of Aedes aegypti mosquitoes. Although there was an increase in dengue cases in January 2014, the number of cases remained below the epidemic threshold throughout the remaining months of 2014. There was no large outbreak of dengue after Haiyan, possibly due to the targeted, multifaceted and rapid response for dengue after Haiyan. However, surveillance differed after Typhoon Haiyan, making comparisons with previous years difficult. Multiple players contributed to the response that was also facilitated by close communication and coordination within the Health Cluster.

  17. [Dengue vaccines. A reality for Argentina?].

    PubMed

    Orellano, Pablo W; Salomón, Oscar D

    2016-01-01

    Dengue outbreaks have occurred yearly in Argentina since 1998. A number of candidate vaccines have been tested in endemic countries. The most advanced one was licensed in three countries of Latin America for children over 9 years of age. In the present article the benefits and drawbacks of these vaccines as well as the challenges for the implementation of a vaccination strategy in Argentina are discussed. Furthermore, a risk stratification strategy with new criteria and a multidisciplinary vision is suggested as a possible path for the assessment of the pertinence of a vaccination program in areas showing the highest risk of dengue transmission and/or for people at the greatest risk of developing severe dengue. It is also suggested that the definition regarding the status of endemicity should take into account the local realities. Finally, this paper proposes a broad discussion on the evidences, the expected impact and instrumental aspects that would be involved in the incorporation of a dengue vaccine, marketed or in development, into the national immunization program, and especially which subpopulation should be targeted for the immunization strategy to be cost-effective.

  18. Human Immune Response to Dengue Infections

    DTIC Science & Technology

    1991-06-30

    complex 32 x 4G2 (Table 35, Exp. 4). A bispecific antibody which is specific for Fc RI and Toxoplasma gondii (32 x anti-TG) did not enhance infection...culture fluids of cells infected with dengue virus alone (Table 36, Exp. 2). A bispecific antibody linking Fc’RII to Toxoplasma gondii (IV.3 x anti-Tg

  19. Dengue vaccine: come let's fight the menace.

    PubMed

    Chawla, Sumit; Sahoo, Soumya Swaroop; Singh, Inderjeet; Verma, Madhur; Gupta, Vikas; Kumari, Sneh

    2015-01-01

    Although dengue has a global distribution, the World Health Organization (WHO) South-East Asia region together with Western Pacific region bears nearly 75% of the current global disease burden. Globally, the societal burden has been estimated to be approximately 528 to 1300 disability-adjusted life years (DALY) per million to populations in endemic regions Dengue is believed to infect 50 to 100 million people worldwide a year with half a million life-threatening infections requiring hospitalization, resulting in approximately 12,500 to 25,000 deaths. Despite being known for decades and nearly half the world's population is at risk for infection with as many as 100 million cases occurring annually, the pitiable state is that we still have no antiviral drugs to treat it and no vaccines to prevent it. In recent years, however, the development of dengue vaccines has accelerated dramatically in tandem with the burgeoning dengue problem with a rejuvenated vigour. However, recent progress in molecular-based vaccine strategies, as well as a renewed commitment by the World Health Organization (WHO) to co-ordinate global efforts on vaccine development, finally provides hope that control of this serious disease may be at hand. Today, several vaccines are in various stages of advanced development, with clinical trials currently underway on 5 candidate vaccines. Trials in the most advanced stages are showing encouraging preliminary data, and the leading candidate could be licensed as early as 2015.

  20. Multiobjective Genetic Algorithm applied to dengue control.

    PubMed

    Florentino, Helenice O; Cantane, Daniela R; Santos, Fernando L P; Bannwart, Bettina F

    2014-12-01

    Dengue fever is an infectious disease caused by a virus of the Flaviridae family and transmitted to the person by a mosquito of the genus Aedes aegypti. This disease has been a global public health problem because a single mosquito can infect up to 300 people and between 50 and 100 million people are infected annually on all continents. Thus, dengue fever is currently a subject of research, whether in the search for vaccines and treatments for the disease or efficient and economical forms of mosquito control. The current study aims to study techniques of multiobjective optimization to assist in solving problems involving the control of the mosquito that transmits dengue fever. The population dynamics of the mosquito is studied in order to understand the epidemic phenomenon and suggest strategies of multiobjective programming for mosquito control. A Multiobjective Genetic Algorithm (MGA_DENGUE) is proposed to solve the optimization model treated here and we discuss the computational results obtained from the application of this technique. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Dengue platelets meet Sir Arthur Conan Doyle.

    PubMed

    Bray, Paul F

    2013-11-14

    In this issue of Blood, Hottz et al provide compelling evidence that dengue virus (DV) induces (1) platelet synthesis of interleukin-1b (IL-1b); (2) platelet-derived IL-1b–containing microvesicles (MVs) that increase vascular permeability; and (3) DV-triggered inflammasome activation in platelets.

  2. Economic Value of Dengue Vaccine in Thailand

    PubMed Central

    Lee, Bruce Y.; Connor, Diana L.; Kitchen, Sarah B.; Bacon, Kristina M.; Shah, Mirat; Brown, Shawn T.; Bailey, Rachel R.; Laosiritaworn, Yongjua; Burke, Donald S.; Cummings, Derek A. T.

    2011-01-01

    With several candidate dengue vaccines under development, this is an important time to help stakeholders (e.g., policy makers, scientists, clinicians, and manufacturers) better understand the potential economic value (cost-effectiveness) of a dengue vaccine, especially while vaccine characteristics and strategies might be readily altered. We developed a decision analytic Markov simulation model to evaluate the potential health and economic value of administering a dengue vaccine to an individual (≤ 1 year of age) in Thailand from the societal perspective. Sensitivity analyses evaluated the effects of ranging various vaccine (e.g., cost, efficacy, side effect), epidemiological (dengue risk), and disease (treatment-seeking behavior) characteristics. A ≥ 50% efficacious vaccine was highly cost-effective [< 1× per capita gross domestic product (GDP) ($4,289)] up to a total vaccination cost of $60 and cost-effective [< 3× per capita GDP ($12,868)] up to a total vaccination cost of $200. When the total vaccine series was $1.50, many scenarios were cost saving. PMID:21540387

  3. Dengue Virus Genome Uncoating Requires Ubiquitination

    PubMed Central

    Byk, Laura A.; Iglesias, Néstor G.; De Maio, Federico A.; Gebhard, Leopoldo G.; Rossi, Mario

    2016-01-01

    ABSTRACT The process of genome release or uncoating after viral entry is one of the least-studied steps in the flavivirus life cycle. Flaviviruses are mainly arthropod-borne viruses, including emerging and reemerging pathogens such as dengue, Zika, and West Nile viruses. Currently, dengue virus is one of the most significant human viral pathogens transmitted by mosquitoes and is responsible for about 390 million infections every year around the world. Here, we examined for the first time molecular aspects of dengue virus genome uncoating. We followed the fate of the capsid protein and RNA genome early during infection and found that capsid is degraded after viral internalization by the host ubiquitin-proteasome system. However, proteasome activity and capsid degradation were not necessary to free the genome for initial viral translation. Unexpectedly, genome uncoating was blocked by inhibiting ubiquitination. Using different assays to bypass entry and evaluate the first rounds of viral translation, a narrow window of time during infection that requires ubiquitination but not proteasome activity was identified. In this regard, ubiquitin E1-activating enzyme inhibition was sufficient to stabilize the incoming viral genome in the cytoplasm of infected cells, causing its retention in either endosomes or nucleocapsids. Our data support a model in which dengue virus genome uncoating requires a nondegradative ubiquitination step, providing new insights into this crucial but understudied viral process. PMID:27353759

  4. Proteinuria during dengue fever in children.

    PubMed

    Andries, Anne-Claire; Duong, Veasna; Cappelle, Julien; Ong, Sivuth; Kerleguer, Alexandra; Ly, Sowath; Tarantola, Arnaud; Horwood, Paul F; Sakuntabhai, Anavaj; Dussart, Philippe; Buchy, Philippe

    2017-02-01

    This study aimed to investigate proteinuria occurring during dengue disease in children and assess if measurement of this parameter can help physicians in the clinical management of patients. Proteinuria was assessed by dipstick and quantified by urine protein:creatinine ratio (UPCR) in samples from patients hospitalized with a confirmed dengue infection and in healthy controls. The dipstick tested positive in 42.9% of the patients presenting at hospital with dengue versus 20.0% in healthy controls. UPCR increased during the critical phase of the disease; peaking one week after fever onset then decreasing as the patients recovered. Patients with warnings signs or severe dengue were more likely to present with proteinuria detected by UPCR at the time of hospital admission compared to patients without warning signs. The sensitivity of this marker, however, was limited as only 16.1% of the patients with warning signs had proteinuria. Urine dipstick and UPCR do not seem to be very valuable for the triage of the patients at the time of the initial consultation but the observation of a decrease of the UPCR during the course of the illness appears to indicate an evolution towards recovery. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. Dengue Virus Serotype 4, Northeastern Peru, 2008

    PubMed Central

    Forshey, Brett M.; Morrison, Amy C.; Cruz, Cristhopher; Rocha, Claudio; Vilcarromero, Stalin; Guevara, Carolina; Camacho, Daria E.; Alava, Araceli; Madrid, César; Beingolea, Luis; Suarez, Víctor; Comach, Guillermo

    2009-01-01

    In 2008, dengue virus serotype 4 (DENV-4) emerged in northeastern Peru, causing a large outbreak and displacing DENV-3, which had predominated for the previous 6 years. Phylogenetic analysis of 2008 and 2009 isolates support their inclusion into DENV-4 genotype II, forming a lineage distinct from strains that had previously circulated in the region. PMID:19891873

  6. Dengue virus serotype 4, northeastern Peru, 2008.

    PubMed

    Forshey, Brett M; Morrison, Amy C; Cruz, Cristhopher; Rocha, Claudio; Vilcarromero, Stalin; Guevara, Carolina; Camacho, Daria E; Alava, Araceli; Madrid, César; Beingolea, Luis; Suarez, Victor; Comach, Guillermo; Kochel, Tadeusz J

    2009-11-01

    In 2008, dengue virus serotype 4 (DENV-4) emerged in northeastern Peru, causing a large outbreak and displacing DENV-3, which had predominated for the previous 6 years. Phylogenetic analysis of 2008 and 2009 isolates support their inclusion into DENV-4 genotype II, forming a lineage distinct from strains that had previously circulated in the region.

  7. Influenza Illness among Case-Patients Hospitalized for Suspected Dengue, El Salvador, 2012.

    PubMed

    Chacon, Rafael; Clara, Alexey Wilfrido; Jara, Jorge; Armero, Julio; Lozano, Celina; El Omeiri, Nathalie; Widdowson, Marc-Alain; Azziz-Baumgartner, Eduardo

    2015-01-01

    We estimate the proportion of patients hospitalized for suspected dengue that tested positive for influenza virus in El Salvador during the 2012 influenza season. We tested specimens from 321 hospitalized patients: 198 patients with SARI and 123 patients with suspected dengue. Among 121 hospitalized suspected dengue (two co-infected excluded) patients, 28% tested positive for dengue and 19% positive for influenza; among 35 with suspected dengue and respiratory symptoms, 14% were positive for dengue and 39% positive for influenza. One percent presented co-infection between influenza and dengue. Clinicians should consider the diagnosis of influenza among patients with suspected dengue during the influenza season.

  8. Influenza Illness among Case-Patients Hospitalized for Suspected Dengue, El Salvador, 2012

    PubMed Central

    Chacon, Rafael; Jara, Jorge; Armero, Julio; Lozano, Celina

    2015-01-01

    We estimate the proportion of patients hospitalized for suspected dengue that tested positive for influenza virus in El Salvador during the 2012 influenza season. We tested specimens from 321 hospitalized patients: 198 patients with SARI and 123 patients with suspected dengue. Among 121 hospitalized suspected dengue (two co-infected excluded) patients, 28% tested positive for dengue and 19% positive for influenza; among 35 with suspected dengue and respiratory symptoms, 14% were positive for dengue and 39% positive for influenza. One percent presented co-infection between influenza and dengue. Clinicians should consider the diagnosis of influenza among patients with suspected dengue during the influenza season. PMID:26485296

  9. Is dengue severity related to nutritional status?

    PubMed

    Kalayanarooj, Siripen; Nimmannitya, Suchitra

    2005-03-01

    A retrospective review of dengue patients admitted to Queen Sirikit National Institute of Child Health (previously known as Children's Hospital) from 1995 to 1999 revealed 4,532 confirmed cases of dengue infection; 80.9% were dengue hemorrhagic fever (DHF) and 19.1% were dengue fever cases (DF). Among the DHF patients; 30.6% had shock. The majority of them, 66.6%, had a normal nutritional status, while 9.3% were malnourished and 24.2% had obesity as classified by weight for age. Compared with control patients with other diagnoses (excluding HIV/AIDS patients), malnourished children had a lower risk of contracting dengue infection (odds ratio = 0.48, 95% Cl = 0.39-0.60, p = 0.000) while obese children had a greater risk of infection with dengue viruses (odds ratio = 1.96, 95% Cl = 1.55-2.5, p = 0.000). The clinical signs, symptoms and laboratory findings of dengue were almost the same among the 3 groups of malnourished, normal, and obese patients. The minor differences observed were that in obese children liver enlargement was found less often; maculopapular/convalescence rash and elevations of alanine aminotransferase were found more often. Malnourished patients had a higher risk of developing shock (37.8%) than normal (29.9%) and obese patients (30.2%) (p = 0.000). Obese patients had more unusual presentations: encephalopathy (1.3%) and associated infections (4.8%), than normal (0.5% and 2.7%) and malnourished patients (1.2% and 3.1%). Complications of fluid overload were found more in obese patients (6.5%) compared to normal (3.2%) and malnourished patients (2.1%) (p = 0.000). The case-fatality rates (CFR) in malnourished patients and obese patients were 0.5% and 0.4%, respectively, while in normal patients the CFR was 0.07%. Under and over nutrition DHF patients had either a greater risk of shock or unusual presentations and complications, which can lead to severe disease or complications and probably a higher CFR.

  10. Visualizing dengue virus through Alexa Fluor labeling.

    PubMed

    Zhang, Summer; Tan, Hwee Cheng; Ooi, Eng Eong

    2011-07-09

    The early events in the interaction between virus and cell can have profound influence on the outcome of infection. Determining the factors that influence this interaction could lead to improved understanding of disease pathogenesis and thus influence vaccine or therapeutic design. Hence, the development of methods to probe this interaction would be useful. Recent advancements in fluorophores development and imaging technology can be exploited to improve our current knowledge on dengue pathogenesis and thus pave the way to reduce the millions of dengue infections occurring annually. The enveloped dengue virus has an external scaffold consisting of 90 envelope glycoprotein (E) dimers protecting the nucleocapsid shell, which contains a single positive strand RNA genome. The identical protein subunits on the virus surface can thus be labeled with an amine reactive dye and visualized through immunofluorescent microscopy. Here, we present a simple method of labeling of dengue virus with Alexa Fluor succinimidyl ester dye dissolved directly in a sodium bicarbonate buffer that yielded highly viable virus after labeling. There is no standardized procedure for the labeling of live virus and existing manufacturer's protocol for protein labeling usually requires the reconstitution of dye in dimethyl sulfoxide. The presence of dimethyl sulfoxide, even in minute quantities, can block productive infection of virus and also induce cell cytotoxicity. The exclusion of the use of dimethyl sulfoxide in this protocol thus reduced this possibility. Alexa Fluor dyes have superior photostability and are less pH-sensitive than the common dyes, such as fluorescein and rhodamine, making them ideal for studies on cellular uptake and endosomal transport of the virus. The conjugation of Alexa Fluor dye did not affect the recognition of labeled dengue virus by virus-specific antibody and its putative receptors in host cells. This method could have useful applications in virological studies.

  11. The successful induction of T-cell and antibody responses by a recombinant measles virus-vectored tetravalent dengue vaccine provides partial protection against dengue-2 infection

    PubMed Central

    Hu, Hui-Mei; Chen, Hsin-Wei; Hsiao, Yu-Ju; Wu, Szu-Hsien; Chung, Han-Hsuan; Hsieh, Chun-Hsiang; Chong, Pele; Leng, Chih-Hsiang; Pan, Chien-Hsiung

    2016-01-01

    ABSTRACT Dengue has a major impact on global public health, and the use of dengue vaccine is very limited. In this study, we evaluated the immunogenicity and protective efficacy of a dengue vaccine made from a recombinant measles virus (MV) that expresses envelope protein domain III (ED3) of dengue-1 to 4. Following immunization with the MV-vectored dengue vaccine, mice developed specific interferon-gamma and antibody responses against dengue virus and MV. Neutralizing antibodies against MV and dengue viruses were also induced, and protective levels of FRNT50 ≥ 10 to 4 serotypes of dengue viruses were detected in the MV-vectored dengue vaccine-immunized mice. In addition, specific interferon-gamma and antibody responses to dengue viruses were still induced by the MV-vectored dengue vaccine in mice that were pre-infected with MV. This finding suggests that the pre-existing immunity to MV did not block the initiation of immune responses. By contrast, mice that were pre-infected with dengue-3 exhibited no effect in terms of their antibody responses to MV and dengue viruses, but a dominant dengue-3-specific T-cell response was observed. After injection with dengue-2, a detectable but significantly lower viremia and a higher titer of anti-dengue-2 neutralizing antibodies were observed in MV-vectored dengue vaccine-immunized mice versus the vector control, suggesting that an anamnestic antibody response that provided partial protection against dengue-2 was elicited. Our results with regard to T-cell responses and the effect of pre-immunity to MV or dengue viruses provide clues for the future applications of an MV-vectored dengue vaccine. PMID:26901482

  12. Molecular and epidemiologic analysis of dengue virus isolates from Somalia.

    PubMed

    Kanesa-thasan, N; Chang, G J; Smoak, B L; Magill, A; Burrous, M J; Hoke, C H

    1998-01-01

    Nucleotide sequence analysis was performed on 14 dengue virus isolates (13 dengue-2 viruses and 1 dengue-3 virus) recovered from febrile soldiers in Somalia in 1993. The dengue-2 viruses were most closely related to dengue-2 virus recovered in Somalia in 1984. However, differences in nucleotide sequence (0.35% to 1.35%) were evident among the 1993 isolates. These differences were closely associated with the geographic location of the infection as well as with different times of infection at the same location. Genetic difference between strains was not associated with differences in clinical features. Molecular analysis of dengue viruses is a useful adjunct to epidemiologic investigation of their distribution over distance and time.

  13. Advances in using Internet searches to track dengue

    PubMed Central

    Yang, Shihao; Kou, Samuel C.; Brownstein, John S.; Brooke, Nicholas

    2017-01-01

    Dengue is a mosquito-borne disease that threatens over half of the world’s population. Despite being endemic to more than 100 countries, government-led efforts and tools for timely identification and tracking of new infections are still lacking in many affected areas. Multiple methodologies that leverage the use of Internet-based data sources have been proposed as a way to complement dengue surveillance efforts. Among these, dengue-related Google search trends have been shown to correlate with dengue activity. We extend a methodological framework, initially proposed and validated for flu surveillance, to produce near real-time estimates of dengue cases in five countries/states: Mexico, Brazil, Thailand, Singapore and Taiwan. Our result shows that our modeling framework can be used to improve the tracking of dengue activity in multiple locations around the world. PMID:28727821

  14. Advances in using Internet searches to track dengue.

    PubMed

    Yang, Shihao; Kou, Samuel C; Lu, Fred; Brownstein, John S; Brooke, Nicholas; Santillana, Mauricio

    2017-07-01

    Dengue is a mosquito-borne disease that threatens over half of the world's population. Despite being endemic to more than 100 countries, government-led efforts and tools for timely identification and tracking of new infections are still lacking in many affected areas. Multiple methodologies that leverage the use of Internet-based data sources have been proposed as a way to complement dengue surveillance efforts. Among these, dengue-related Google search trends have been shown to correlate with dengue activity. We extend a methodological framework, initially proposed and validated for flu surveillance, to produce near real-time estimates of dengue cases in five countries/states: Mexico, Brazil, Thailand, Singapore and Taiwan. Our result shows that our modeling framework can be used to improve the tracking of dengue activity in multiple locations around the world.

  15. [Evaluation of the Brazilian National Dengue Control Plan].

    PubMed

    Pessanha, José Eduardo Marques; Caiaffa, Waleska Teixeira; César, Cibele Comini; Proietti, Fernando Augusto

    2009-07-01

    This study aimed to describe and evaluate dengue patterns after the implementation of the National Dengue Control Plan (PNCD). Incidence rates were analyzed and correlated with previous rates and climatic, demographic, and socioeconomic variables for the Brazilian municipalities that were targeted for priority dengue control. We conducted descriptive studies of epidemiological indicators after the implementation of the national plan and a statistical analysis considering the incidence rates from the previous period and climatic, demographic, and socioeconomic variables, using multiple linear regression. We found a significant association between dengue incidence during the period following implementation of the PNCD (2003-2006) as compared to pre-implementation (2001-2002), after adjusting for geographic and climatic indicators. Our findings suggest that the plan's objectives were not fully achieved. In conclusion, the persistent occurrence of dengue epidemics requires changes and reevaluation of current strategies, along with improvements in the dengue surveillance system.

  16. Economic Impact of Dengue Illness in the Americas

    PubMed Central

    Shepard, Donald S.; Coudeville, Laurent; Halasa, Yara A.; Zambrano, Betzana; Dayan, Gustavo H.

    2011-01-01

    The growing burden of dengue in endemic countries and outbreaks in previously unaffected countries stress the need to assess the economic impact of this disease. This paper synthesizes existing studies to calculate the economic burden of dengue illness in the Americas from a societal perspective. Major data sources include national case reporting data from 2000 to 2007, prospective cost of illness studies, and analyses quantifying underreporting in national routine surveillance systems. Dengue illness in the Americas was estimated to cost $2.1 billion per year on average (in 2010 US dollars), with a range of $1–4 billion in sensitivity analyses and substantial year to year variation. The results highlight the substantial economic burden from dengue in the Americas. The burden for dengue exceeds that from other viral illnesses, such as human papillomavirus (HPV) or rotavirus. Because this study does not include some components (e.g., vector control), it may still underestimate total economic consequences of dengue. PMID:21292885

  17. Cardiac tamponade presenting as early manifestation in dengue fever.

    PubMed

    Bendwal, Suresh; Malviya, Kavita; Jatav, O P; Malviya, Kapil

    2014-03-01

    Dengue fever (DF) is an outbreak prone viral disease transmitted by aedes mosquitoes. It is often associated with evidence of plasma leakage due to increased vascular permeability manifested by pleural effusion, ascites, hypoproteinaemia and pericardial effusion. Cases of small pericardial effusion have been reported in association with dengue fever, largely with dengue haemorrhagic fever (DHF) during epidemic outbreaks. Dengue may rarely present with cardiac tamponade as early manifestation and urgent pericardiocentesis is life saving. A 34 year old male presented with low grade fever, headache, myalgia and breathlessness. Echocardiography revealed large pericardial effusion with right ventricular diagnostic collapse requiring urgent drainage. Subsequently patient improved. Dengue serology (both IgM and IgG) was reported as markedly elevated supporting a diagnosis of classic dengue fever.

  18. Underrecognition of Dengue during 2013 Epidemic in Luanda, Angola.

    PubMed

    Sharp, Tyler M; Moreira, Rosa; Soares, Maria José; Miguel da Costa, Lúis; Mann, Jennifer; DeLorey, Mark; Hunsperger, Elizabeth; Muñoz-Jordán, Jorge L; Colón, Candimar; Margolis, Harold S; de Caravalho, Adelaide; Tomashek, Kay M

    2015-08-01

    During the 2013 dengue epidemic in Luanda, Angola, 811 dengue rapid diagnostic test-positive cases were reported to the Ministry of Health. To better understand the magnitude of the epidemic and identify risk factors for dengue virus (DENV) infection, we conducted cluster surveys around households of case-patients and randomly selected households 6 weeks after the peak of the epidemic. Of 173 case cluster participants, 16 (9%) exhibited evidence of recent DENV infection. Of 247 random cluster participants, 25 (10%) had evidence of recent DENV infection. Of 13 recently infected participants who had a recent febrile illness, 7 (54%) had sought medical care, and 1 (14%) was hospitalized with symptoms consistent with severe dengue; however, none received a diagnosis of dengue. Behavior associated with protection from DENV infection included recent use of mosquito repellent or a bed net. These findings suggest that the 2013 dengue epidemic was larger than indicated by passive surveillance data.

  19. Evaluation of Internet-Based Dengue Query Data: Google Dengue Trends

    PubMed Central

    Gluskin, Rebecca Tave; Johansson, Michael A.; Santillana, Mauricio; Brownstein, John S.

    2014-01-01

    Dengue is a common and growing problem worldwide, with an estimated 70–140 million cases per year. Traditional, healthcare-based, government-implemented dengue surveillance is resource intensive and slow. As global Internet use has increased, novel, Internet-based disease monitoring tools have emerged. Google Dengue Trends (GDT) uses near real-time search query data to create an index of dengue incidence that is a linear proxy for traditional surveillance. Studies have shown that GDT correlates highly with dengue incidence in multiple countries on a large spatial scale. This study addresses the heterogeneity of GDT at smaller spatial scales, assessing its accuracy at the state-level in Mexico and identifying factors that are associated with its accuracy. We used Pearson correlation to estimate the association between GDT and traditional dengue surveillance data for Mexico at the national level and for 17 Mexican states. Nationally, GDT captured approximately 83% of the variability in reported cases over the 9 study years. The correlation between GDT and reported cases varied from state to state, capturing anywhere from 1% of the variability in Baja California to 88% in Chiapas, with higher accuracy in states with higher dengue average annual incidence. A model including annual average maximum temperature, precipitation, and their interaction accounted for 81% of the variability in GDT accuracy between states. This climate model was the best indicator of GDT accuracy, suggesting that GDT works best in areas with intense transmission, particularly where local climate is well suited for transmission. Internet accessibility (average ∼36%) did not appear to affect GDT accuracy. While GDT seems to be a less robust indicator of local transmission in areas of low incidence and unfavorable climate, it may indicate cases among travelers in those areas. Identifying the strengths and limitations of novel surveillance is critical for these types of data to be used to make

  20. Clinical Score to Differentiate Scrub Typhus and Dengue: A Tool to Differentiate Scrub Typhus and Dengue

    PubMed Central

    Mitra, Shubhanker; Gautam, Ira; Jambugulam, Mohan; Abhilash, Kundavaram Paul Prabhakar; Jayaseeelan, Vishalakshi

    2017-01-01

    Background: Dengue and scrub typhus share similar clinical and epidemiological features, and are difficult to differentiate at initial presentation. Many places are endemic to both these infections where they comprise the majority of acute undifferentiated febrile illnesses. Materials and Methods: We aimed to develop a score that can differentiate scrub typhus from dengue. In this cross-sectional study, 188 cases of scrub typhus and 201 cases of dengue infection who presented to the emergency department or medicine outpatient clinic from September 2012 to April 2013 were included. Univariate followed by multivariate logistic regression analysis was performed to identify clinical features and laboratory results that were significantly different between the two groups. Each variable was assigned scores based on the strength of association and receiver operating characteristics area under the curve (ROC-AUC) was generated and compared. Six scoring models were explored to ascertain the model with the best fit. Results: Model 2 was developed using the following six variables: oxygen saturation (>90%, ≤90%), total white blood cell count (<4000, 4001–7000 and >7000 cells/cumm), hemoglobin (≤14 and >14 g/dL), total bilirubin (<2 and ≥2 mg/dL), serum glutamic oxaloacetic transaminase (>200 and ≥200 IU/dL), and altered sensorium (present or absent). Each variable was assigned scores based on its strength of association. The AUC-ROC curve (95% confidence interval) for model 2 was 0.84 (0.79–0.89). At the cut off score of 13, the sensitivity and specificity were 85% and 77% respectively, with a higher score favoring dengue. Conclusion: In areas of high burden of ST and dengue, model 2 (the “clinical score to differentiate scrub typhus and dengue fever”) is a simple and rapid clinical scoring system that may be used to differentiate scrub typhus and dengue at initial presentation. PMID:28250620

  1. Evaluation of Internet-based dengue query data: Google Dengue Trends.

    PubMed

    Gluskin, Rebecca Tave; Johansson, Michael A; Santillana, Mauricio; Brownstein, John S

    2014-02-01

    Dengue is a common and growing problem worldwide, with an estimated 70-140 million cases per year. Traditional, healthcare-based, government-implemented dengue surveillance is resource intensive and slow. As global Internet use has increased, novel, Internet-based disease monitoring tools have emerged. Google Dengue Trends (GDT) uses near real-time search query data to create an index of dengue incidence that is a linear proxy for traditional surveillance. Studies have shown that GDT correlates highly with dengue incidence in multiple countries on a large spatial scale. This study addresses the heterogeneity of GDT at smaller spatial scales, assessing its accuracy at the state-level in Mexico and identifying factors that are associated with its accuracy. We used Pearson correlation to estimate the association between GDT and traditional dengue surveillance data for Mexico at the national level and for 17 Mexican states. Nationally, GDT captured approximately 83% of the variability in reported cases over the 9 study years. The correlation between GDT and reported cases varied from state to state, capturing anywhere from 1% of the variability in Baja California to 88% in Chiapas, with higher accuracy in states with higher dengue average annual incidence. A model including annual average maximum temperature, precipitation, and their interaction accounted for 81% of the variability in GDT accuracy between states. This climate model was the best indicator of GDT accuracy, suggesting that GDT works best in areas with intense transmission, particularly where local climate is well suited for transmission. Internet accessibility (average ∼ 36%) did not appear to affect GDT accuracy. While GDT seems to be a less robust indicator of local transmission in areas of low incidence and unfavorable climate, it may indicate cases among travelers in those areas. Identifying the strengths and limitations of novel surveillance is critical for these types of data to be used to make

  2. Meteorologically Driven Simulations of Dengue Epidemics in San Juan, PR

    PubMed Central

    Morin, Cory W.; Monaghan, Andrew J.; Hayden, Mary H.; Barrera, Roberto; Ernst, Kacey

    2015-01-01

    Meteorological factors influence dengue virus ecology by modulating vector mosquito population dynamics, viral replication, and transmission. Dynamic modeling techniques can be used to examine how interactions among meteorological variables, vectors and the dengue virus influence transmission. We developed a dengue fever simulation model by coupling a dynamic simulation model for Aedes aegypti, the primary mosquito vector for dengue, with a basic epidemiological Susceptible-Exposed-Infectious-Recovered (SEIR) model. Employing a Monte Carlo approach, we simulated dengue transmission during the period of 2010–2013 in San Juan, PR, where dengue fever is endemic. The results of 9600 simulations using varied model parameters were evaluated by statistical comparison (r2) with surveillance data of dengue cases reported to the Centers for Disease Control and Prevention. To identify the most influential parameters associated with dengue virus transmission for each period the top 1% of best-fit model simulations were retained and compared. Using the top simulations, dengue cases were simulated well for 2010 (r2 = 0.90, p = 0.03), 2011 (r2 = 0.83, p = 0.05), and 2012 (r2 = 0.94, p = 0.01); however, simulations were weaker for 2013 (r2 = 0.25, p = 0.25) and the entire four-year period (r2 = 0.44, p = 0.002). Analysis of parameter values from retained simulations revealed that rain dependent container habitats were more prevalent in best-fitting simulations during the wetter 2010 and 2011 years, while human managed (i.e. manually filled) container habitats were more prevalent in best-fitting simulations during the drier 2012 and 2013 years. The simulations further indicate that rainfall strongly modulates the timing of dengue (e.g., epidemics occurred earlier during rainy years) while temperature modulates the annual number of dengue fever cases. Our results suggest that meteorological factors have a time-variable influence on dengue transmission relative to other important

  3. Imported dengue virus serotype 1 from Madeira to Finland 2012.

    PubMed

    Huhtamo, E; Korhonen, Em; Vapalahti, O

    2013-02-21

    Imported dengue cases originating from the Madeiran outbreak are increasingly reported. In 2012 five Finnish travellers returning from Madeira were diagnosed with dengue fever. Viral sequence data was obtained from two patients. The partial C-preM sequences (399 and 396 bp respectively) were found similar to that of an autochthonous case from Madeira. The partial E-gene sequence (933 bp) which was identical among the two patients grouped phylogenetically with South American strains of dengue virus serotype 1.

  4. Knowledge, attitudes and practices regarding dengue infection in Westmoreland, Jamaica

    PubMed Central

    Shuaib, Faisal; Todd, Dana; Campbell-Stennett, Dianne; Ehiri, John; Jolly, Pauline E.

    2010-01-01

    Background Dengue virus infection causes significant morbidity and mortality in most tropical and sub-tropical countries of the world. Dengue fever is endemic in Jamaica and continues to be a public health concern. There is a paucity of information on knowledge, attitudes, and practices (KAP) of Jamaicans regarding dengue infection. Objective To describe dengue related knowledge, attitudes and practices (KAP) of residents of Westmoreland, Jamaica. Methods A cross-sectional questionnaire survey of 192 parents attending child health clinics in the Parish of Westmoreland was conducted. Results More than half of the parents (54%) had good knowledge about signs, symptoms, and modes of transmission of dengue. Approximately 47% considered dengue to be a serious but preventable disease to which they are vulnerable. Nevertheless, a majority (77%) did not use effective dengue preventive methods such as screening of homes and 51% did not use bed nets. Educational attainment (OR, 2.98; CI, 1.23–7.23) was positively associated with knowledge of dengue. There was no correlation between knowledge about dengue and preventive practices (p=0.34). Radio and TV were the predominant sources of information about dengue fever. Conclusion Our findings suggest that the good knowledge about dengue fever among residents of Westmoreland did not translate to adoption of preventive measures. Health program planners and practitioners need to identify and facilitate removal of barriers to behavior change related to control of dengue fever among the population. Future campaigns should focus on educating and encouraging individuals and families to adopt such simple, inexpensive preventive actions, such as, use of insecticide treated bed nets and screening of homes. PMID:21132094

  5. Fatal Dengue Myocarditis despite the Use of Extracorporeal Membrane Oxygenation

    PubMed Central

    2016-01-01

    Dengue is an important mosquitoes-borne viral disease which is endemic in tropics and subtropics region. Rapid spreading of disease to previously unaffected region was found in recent years. Atypical manifestations, such as myocarditis, were reported during large outbreak. There is a wide range of clinical manifestations of cardiac involvement in dengue, but rarely fatal. Here we reported a case of fulminant dengue myocarditis in fatal outcome despite cardiac mechanical support. PMID:28018687

  6. Dengue Type 3 Virus, Saint Martin, 2003–2004

    PubMed Central

    Pastorino, Boris A.M.; Bessaud, Maël; Gravier, Patrick; Tock, Fabienne; Couissinier-Paris, Patricia; Martial, Jenny; Huc-Anais, Patricia; Césaire, Raymond; Grandadam, Marc; Tolou, Hugues J.

    2005-01-01

    We describe the spread of a dengue virus during an outbreak in Saint Martin island (French West Indies) during winter 2003–2004. Dengue type 3 viruses were isolated from 6 patients exhibiting clinical symptoms. This serotype had not been detected on the island during the preceding 3 years. Genome sequence determinations and analyses showed a common origin with dengue type 3 viruses isolated in Martinique 2 years earlier. PMID:15890134

  7. The Clinical and Serological Profile of Pediatric Dengue.

    PubMed

    Ramabhatta, Sujatha; Palaniappan, Saravanan; Hanumantharayappa, Navya; Begum, Shaik Vajidunnisa

    2017-09-08

    To classify suspected dengue into dengue, dengue with warning signs and severe dengue, based on clinical features as per the revised WHO guidelines with special emphasis on serology. It was a prospective cross-sectional study for five years from 2011-2016 in a tertiary care medical college hospital in Bangalore. All cases of fever of three to five days duration with symptoms like dengue were enrolled for the study. They were categorized into three groups as per the Revised WHO 2012 criteria. Laboratory parameters, serology, ultrasound abdomen and X-ray were done in almost all patients. Data was analysed by SPSS software, version 16, and different groups were compared with Chi square test. Five hundred sixty eight children were diagnosed to have dengue fever; 4.2% of the sample belonged to infancy. Majority were in the age group of 5-10 y (42.6%). Fever and flushing were present in majority of the children. Gastrointestinal bleed was more commonly seen in the severe dengue group. Dengue nonstructural protein antigen (NS1Ag) was positive in 78%, immunoglobulin M (IgM) in 15.8% and immunoglobulin G (IgG) in 14.6%. Children with IgG had more complications, though not statistically significant. Mortality was reported in 1.2%. Dengue serology helped to confirm the diagnosis, however did not help in patient management. There is a considerable overlap in the symptomatology of dengue with warning signs and severe dengue. More studies are required on the severity and type of response to treatment in infants and obese adoloscents with severe dengue.

  8. The Effects of Weather and Climate Change on Dengue

    PubMed Central

    Colón-González, Felipe J.; Fezzi, Carlo; Lake, Iain R.; Hunter, Paul R.

    2013-01-01

    Background There is much uncertainty about the future impact of climate change on vector-borne diseases. Such uncertainty reflects the difficulties in modelling the complex interactions between disease, climatic and socioeconomic determinants. We used a comprehensive panel dataset from Mexico covering 23 years of province-specific dengue reports across nine climatic regions to estimate the impact of weather on dengue, accounting for the effects of non-climatic factors. Methods and Findings Using a Generalized Additive Model, we estimated statistically significant effects of weather and access to piped water on dengue. The effects of weather were highly nonlinear. Minimum temperature (Tmin) had almost no effect on dengue incidence below 5°C, but Tmin values above 18°C showed a rapidly increasing effect. Maximum temperature above 20°C also showed an increasing effect on dengue incidence with a peak around 32°C, after which the effect declined. There is also an increasing effect of precipitation as it rose to about 550 mm, beyond which such effect declines. Rising access to piped water was related to increasing dengue incidence. We used our model estimations to project the potential impact of climate change on dengue incidence under three emission scenarios by 2030, 2050, and 2080. An increase of up to 40% in dengue incidence by 2080 was estimated under climate change while holding the other driving factors constant. Conclusions Our results indicate that weather significantly influences dengue incidence in Mexico and that such relationships are highly nonlinear. These findings highlight the importance of using flexible model specifications when analysing weather–health interactions. Climate change may contribute to an increase in dengue incidence. Rising access to piped water may aggravate dengue incidence if it leads to increased domestic water storage. Climate change may therefore influence the success or failure of future efforts against dengue. PMID:24244765

  9. Enhancing the Immunogenicity of a Tetravalent Dengue DNA Vaccine

    DTIC Science & Technology

    2016-08-01

    AWARD NUMBER: W81XWH-15-2-0029 TITLE: Enhancing the Immunogenicity of a Tetravalent Dengue DNA Vaccine PRINCIPAL INVESTIGATOR: Maya...TITLE AND SUBTITLE Enhancing the Immunogenicity of a Tetravalent Dengue DNA 5a. CONTRACT NUMBER Vaccine 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...personnel is priority research area for the US DoD. Phase 1 clinical trials demonstrated that the Naval Medical Research Center’s DNA based dengue vaccine

  10. Field Evaluation of Lethal Ovitrap against Dengue Vectors

    DTIC Science & Technology

    2005-04-01

    AD Award Number: DAMD17-02-1-0217 TITLE: Field Evaluation of Lethal Ovitrap against Dengue Vectors PRINCIPAL INVESTIGATOR: Dr. Lane Foil CONTRACTING...2005 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Field Evaluation of Lethal Ovitrap against Dengue Vectors 5b. GRANT NUMBER DAMD17-02-1-0217 5c. PROGRAM...to effectively sample dengue mosquito vector populations, particularly Aedes aegypti for over a decade. Modifying a standard ovitrap by incorporating

  11. Dengue Serotypes 2 and 3 in US Forces in Somalia

    DTIC Science & Technology

    1994-01-01

    Reduction Project (0704-0 188). Wasnington. DC 20503 DATE 3. REPORT TYPE AND DATES COVERED 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS Dengue serotynes 2...illnesses among US forces in Som3lia revealed dengue viruses as an important identifiable cause. 90 consecutively admitted patients temperatures of...at least 38.10 C were studied. Flavivirus infection was confirmed by positive dengue IgM and/or hemagluttinin inhibition tests in 15 of 84 individuals

  12. Meteorologically Driven Simulations of Dengue Epidemics in San Juan, PR.

    PubMed

    Morin, Cory W; Monaghan, Andrew J; Hayden, Mary H; Barrera, Roberto; Ernst, Kacey

    2015-08-01

    Meteorological factors influence dengue virus ecology by modulating vector mosquito population dynamics, viral replication, and transmission. Dynamic modeling techniques can be used to examine how interactions among meteorological variables, vectors and the dengue virus influence transmission. We developed a dengue fever simulation model by coupling a dynamic simulation model for Aedes aegypti, the primary mosquito vector for dengue, with a basic epidemiological Susceptible-Exposed-Infectious-Recovered (SEIR) model. Employing a Monte Carlo approach, we simulated dengue transmission during the period of 2010-2013 in San Juan, PR, where dengue fever is endemic. The results of 9600 simulations using varied model parameters were evaluated by statistical comparison (r2) with surveillance data of dengue cases reported to the Centers for Disease Control and Prevention. To identify the most influential parameters associated with dengue virus transmission for each period the top 1% of best-fit model simulations were retained and compared. Using the top simulations, dengue cases were simulated well for 2010 (r2 = 0.90, p = 0.03), 2011 (r2 = 0.83, p = 0.05), and 2012 (r2 = 0.94, p = 0.01); however, simulations were weaker for 2013 (r2 = 0.25, p = 0.25) and the entire four-year period (r2 = 0.44, p = 0.002). Analysis of parameter values from retained simulations revealed that rain dependent container habitats were more prevalent in best-fitting simulations during the wetter 2010 and 2011 years, while human managed (i.e. manually filled) container habitats were more prevalent in best-fitting simulations during the drier 2012 and 2013 years. The simulations further indicate that rainfall strongly modulates the timing of dengue (e.g., epidemics occurred earlier during rainy years) while temperature modulates the annual number of dengue fever cases. Our results suggest that meteorological factors have a time-variable influence on dengue transmission relative to other important

  13. Dengue Contingency Planning: From Research to Policy and Practice

    PubMed Central

    Runge-Ranzinger, Silvia; Kroeger, Axel; Olliaro, Piero; McCall, Philip J.; Sánchez Tejeda, Gustavo; Lloyd, Linda S.; Hakim, Lokman; Bowman, Leigh R.; Horstick, Olaf; Coelho, Giovanini

    2016-01-01

    Background Dengue is an increasingly incident disease across many parts of the world. In response, an evidence-based handbook to translate research into policy and practice was developed. This handbook facilitates contingency planning as well as the development and use of early warning and response systems for dengue fever epidemics, by identifying decision-making processes that contribute to the success or failure of dengue surveillance, as well as triggers that initiate effective responses to incipient outbreaks. Methodology/Principal findings Available evidence was evaluated using a step-wise process that included systematic literature reviews, policymaker and stakeholder interviews, a study to assess dengue contingency planning and outbreak management in 10 countries, and a retrospective logistic regression analysis to identify alarm signals for an outbreak warning system using datasets from five dengue endemic countries. Best practices for managing a dengue outbreak are provided for key elements of a dengue contingency plan including timely contingency planning, the importance of a detailed, context-specific dengue contingency plan that clearly distinguishes between routine and outbreak interventions, surveillance systems for outbreak preparedness, outbreak definitions, alert algorithms, managerial capacity, vector control capacity, and clinical management of large caseloads. Additionally, a computer-assisted early warning system, which enables countries to identify and respond to context-specific variables that predict forthcoming dengue outbreaks, has been developed. Conclusions/Significance Most countries do not have comprehensive, detailed contingency plans for dengue outbreaks. Countries tend to rely on intensified vector control as their outbreak response, with minimal focus on integrated management of clinical care, epidemiological, laboratory and vector surveillance, and risk communication. The Technical Handbook for Surveillance, Dengue Outbreak

  14. Cross-serotype neutralization of dengue virus in Aotus nancymae monkeys.

    PubMed

    Kochel, Tadeusz J; Watts, Douglas M; Gozalo, Alfonso S; Ewing, Daniel F; Porter, Kevin R; Russell, Kevin L

    2005-03-15

    Previously, we observed that serum from humans immune to dengue serotype 1 (dengue-1) neutralized the American genotype of dengue serotype 2 (American-2) to a greater extent than it neutralized the Asian genotype of dengue serotype 2 (Asian-2). To determine if this activity is protective, Aotus nancymae monkeys were infected with dengue-1 followed by either American-2 or Asian-2. Dengue-1-infected animals produced antibody with neutralizing titers of 2656 antibodies against dengue-1, 409 against American-2, and <20 against Asian-2. Infection with American-2 did not produce detectable viremia in either dengue-1-immune or dengue-1-naive animals. These findings support the hypothesis that dengue-1 immunity might have prevented disease or altered the severity of disease in individuals sequentially infected with dengue-1 and American-2.

  15. Dengue serotype surveillance among patients admitted for dengue in two major hospitals in Selangor, Malaysia, 2010-2011.

    PubMed

    Ab-Fatah, M; Subenthiran, S; Abdul-Rahman, P S A; Saat, Z; Thayan, R

    2015-03-01

    Dengue serotype surveillance is important as any changes in serotype distribution may result in an outbreak or increase in severe dengue cases. This study aimed to determine circulating dengue serotypes in two hospitals in Selangor. Serum samples were collected from patients admitted for dengue at these two major public hospitals i.e. Hospital Sungai Buloh (HSB) and Hospital Tunku Ampuan Rahimah (HTAR) between November 2010 and August 2011 and subjected to real-time RT-PCR using SYBR® Green. All four dengue serotypes were detected in samples from both hospitals. The predominating serotype was dengue 1 in samples from both hospitals (HSB, DENV-1; 25.53 % and HTAR, DENV-1; 32.1 %).

  16. The growing burden of dengue in Latin America.

    PubMed

    Tapia-Conyer, Roberto; Méndez-Galván, Jorge F; Gallardo-Rincón, Héctor

    2009-10-01

    The re-emergence and subsequent failure to control dengue in Latin America provides a compelling illustration of the clinical, political and socio-economic challenges to eradicating dengue across the world. Insufficient political commitment, inadequate financial resources and increased urbanisation have contributed to the re-emergence and dramatic increase in dengue fever and dengue haemorrhagic fever in all 19 Latin American countries previously certified as free of Aedes aegypti. Difficulties with diagnosis, asymptomatic infection and the lack of effective surveillance systems account for the discrepancies between antibody prevalence against dengue and reported cases. Accurate incidence data and appreciation of the economic impact of dengue at regional, national and international levels are essential to securing political and economic commitment for dengue control efforts as well as increased scientific and social awareness. Environmental control efforts require an integrated and systematic approach at both the national and community level, while successful introduction of a dengue vaccine will require an educational programme that clearly communicates the cost-effectiveness and desirability of this interventional measure. In addition, countries must anticipate their national regulatory requirements, and vaccination strategies should be optimised according to the dengue epidemiology of each country. A broad scope is required to finance vaccination programmes to ensure individual countries' monetary shortcomings are addressed.

  17. Latest developments and future directions in dengue vaccines

    PubMed Central

    Thisyakorn, Chule

    2014-01-01

    Dengue is a mosquito-borne disease which is currently an expanding global health problem. The disease is caused by four closely related viruses, the dengue virus. There are no specific dengue therapeutics and prevention is currently limited to vector control measures. Development of an effective tetravalent dengue vaccine would therefore represent a major advance in the control of the disease and is considered a high public health priority. While a licensed dengue vaccine is not yet available, the scope and intensity of dengue vaccine development has increased dramatically in the last decade. The uniqueness of the dengue viruses and the spectrum of disease resulting from infection have made dengue vaccine development difficult. Several vaccine candidates are currently being evaluated in clinical studies. The candidate currently at the most advanced clinical development stage, a live-attenuated tetravalent vaccine based on chimeric yellow fever dengue virus, has progressed to phase III efficacy studies. Several other live-attenuated vaccines, as well as subunit, DNA and purified inactivated vaccine candidates, are at earlier stages of clinical development. Additional technological approaches, such as virus-vectored and virus-like particle-based vaccines, are under evaluation in preclinical studies. PMID:24757522

  18. The 2012 dengue outbreak in Madeira: exploring the origins.

    PubMed

    Wilder-Smith, A; Quam, M; Sessions, O; Rocklov, J; Liu-Helmersson, J; Franco, L; Khan, K

    2014-02-27

    In 2012, Madeira reported its first major outbreak of dengue. To identify the origin of the imported dengue virus, we investigated the interconnectivity via air travel between dengue-endemic countries and Madeira, and compared available sequences against GenBank. There were 22,948 air travellers to Madeira in 2012, originating from twenty-nine dengue-endemic countries; 89.6% of these international travellers originated from Venezuela and Brazil. We developed an importation index that takes into account both travel volume and the extent of dengue incidence in the country of origin. Venezuela and Brazil had by far the highest importation indices compared with all other dengue-endemic countries. The importation index for Venezuela was twice as high as that for Brazil. When taking into account seasonality in the months preceding the onset of the Madeira outbreak, this index was even seven times higher for Venezuela than for Brazil during this time. Dengue sequencing shows that the virus responsible for the Madeira outbreak was most closely related to viruses circulating in Venezuela, Brazil and Columbia. Applying the importation index, Venezuela was identified as the most likely origin of importation of dengue virus via travellers to Madeira. We propose that the importation index is a new additional tool that can help to identify and anticipate the most probable country of origin for importation of dengue into currently non-endemic countries.

  19. Dengue virus life cycle: viral and host factors modulating infectivity.

    PubMed

    Rodenhuis-Zybert, Izabela A; Wilschut, Jan; Smit, Jolanda M

    2010-08-01

    Dengue virus (DENV 1-4) represents a major emerging arthropod-borne pathogen. All four DENV serotypes are prevalent in the (sub) tropical regions of the world and infect 50-100 million individuals annually. Whereas the majority of DENV infections proceed asymptomatically or result in self-limited dengue fever, an increasing number of patients present more severe manifestations, such as dengue hemorrhagic fever and dengue shock syndrome. In this review we will give an overview of the infectious life cycle of DENV and will discuss the viral and host factors that are important in controlling DENV infection.

  20. Agent-based modeling to simulate the dengue spread

    NASA Astrophysics Data System (ADS)

    Deng, Chengbin; Tao, Haiyan; Ye, Zhiwei

    2008-10-01

    In this paper, we introduce a novel method ABM in simulating the unique process for the dengue spread. Dengue is an acute infectious disease with a long history of over 200 years. Unlike the diseases that can be transmitted directly from person to person, dengue spreads through a must vector of mosquitoes. There is still no any special effective medicine and vaccine for dengue up till now. The best way to prevent dengue spread is to take precautions beforehand. Thus, it is crucial to detect and study the dynamic process of dengue spread that closely relates to human-environment interactions where Agent-Based Modeling (ABM) effectively works. The model attempts to simulate the dengue spread in a more realistic way in the bottom-up way, and to overcome the limitation of ABM, namely overlooking the influence of geographic and environmental factors. Considering the influence of environment, Aedes aegypti ecology and other epidemiological characteristics of dengue spread, ABM can be regarded as a useful way to simulate the whole process so as to disclose the essence of the evolution of dengue spread.

  1. Recent expansion of dengue virus serotype 3 in West Africa.

    PubMed

    Franco, L; Di Caro, A; Carletti, F; Vapalahti, O; Renaudat, C; Zeller, H; Tenorio, A

    2010-02-18

    Due to non-existing or limited surveillance in Africa, little is known about the epidemiology of dengue illness in the continent. Serological and virological data obtained from returning European travellers is a key complement to this often flawed information. In the past years, dengue 3 virus has emerged in West Africa and has been detected in travellers returning to Europe. The first dengue epidemic in Cape Verde with more than 17,000 cases from September to December 2009 demonstrated that dengue virus is still expanding worldwide to new territories.

  2. Investigational drugs in early development for treating dengue infection.

    PubMed

    Beesetti, Hemalatha; Khanna, Navin; Swaminathan, Sathyamangalam

    2016-09-01

    Dengue has emerged as the most significant arboviral disease of the current century. A drug for dengue is an urgent unmet need. As conventional drug discovery efforts have not produced any promising clinical candidates, there is a shift toward re-positioning pre-existing drugs for dengue to fast-track dengue drug development. This article provides an update on the current status of recently completed and ongoing dengue drug trials. All dengue drug trials described in this article were identified from a list of >230 trials that were returned upon searching the World Health Organization's International Clinical Trials Registry Platform web portal using the search term 'dengue' on December 31(st), 2015. None of the handful of drugs tested so far has yielded encouraging results. Early trial experience has served to emphasize the challenge of drug testing in the short therapeutic time window available, the need for tools to predict 'high-risk' patients early on and the limitations of the existing pre-clinical model systems. Significant investment of efforts and resources is a must before the availability of a safe, effective and inexpensive dengue drug becomes a reality. Currently, supportive fluid therapy remains the only option available for dengue treatment.

  3. Serological Evidence of Dengue Fever Among Refugees, Hargeysa, Somalia

    DTIC Science & Technology

    1989-01-01

    AD-A24 1 179 Q O0T!119910 j •___ C PUBLICATION REPORT 1602 84/89-90 SEROLOGICAL EVIDENCE OF DENGUE FEVER AMONG REFUGEES, HARGEYOA, SOMALIA BY Boulos...of Dengue Fever Among Refugees, Hargeysa, Somalia Boulos A.M. Botros, Douglas M. Watts, Atef K. Soliman, Adel W. Salib, Mahmoud I. Moussa, H. Mursal...Tukei PM 1982). Epidemic Dengue fever caused by Dengue tion, antibody demonstrated by the EIA, IFA, and HI type-2 virus in Kenya: Preliminary results

  4. Dengue fever mimicking acute appendicitis: A case report.

    PubMed

    McFarlane, M E C; Plummer, J M; Leake, P A; Powell, L; Chand, V; Chung, S; Tulloch, K

    2013-01-01

    Dengue fever is an acute viral disease, which usually presents as a mild febrile illness. Patients with severe disease present with dengue haemorrhagic fever or dengue toxic shock syndrome. Rarely, it presents with abdominal symptoms mimicking acute appendicitis. We present a case of a male patient presenting with right iliac fossa pain and suspected acute appendicitis that was later diagnosed with dengue fever following a negative appendicectomy. A 13-year old male patient presented with fever, localized right-sided abdominal pain and vomiting. Abdominal ultrasound was not helpful and appendicectomy was performed due to worsening abdominal signs and an elevated temperature. A normal appendix with enlarged mesenteric nodes was found at surgery. Complete blood count showed thrombocytopenia with leucopenia. Dengue fever was now suspected and confirmed by IgM enzyme-linked immunosorbent assay against dengue virus. This unusual presentation of dengue fever mimicking acute appendicitis should be suspected during viral outbreaks and in patients with atypical symptoms and cytopenias on blood evaluation in order to prevent unnecessary surgery. This case highlights the occurrence of abdominal symptoms and complications that may accompany dengue fever. Early recognition of dengue fever mimicking acute appendicitis will avoid non-therapeutic operation and the diagnosis may be aided by blood investigations indicating a leucopenia, which is uncommon in patients with suppurative acute appendicitis. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. Seir Model for Transmission of Dengue Fever in Selangor Malaysia

    NASA Astrophysics Data System (ADS)

    Syafruddin, S.; Noorani, M. S. M.

    In this paper, we study a system of differential equations that models the population dynamics of SEIR vector transmission of dengue fever. The model studied breeding value based on the number of reported cases of dengue fever in Selangor because the state had the highest case in Malaysia. The model explains that maximum level of human infection rate of dengue fever achieved in a very short period. It is also revealed that there existed suitability result between theoretical and empirical calculation using the model. The result of SEIR model will hopefully provide an insight into the spread of dengue fever in Selangor Malaysia and basic form for modeling this area.

  6. Clinical and Virological Features of Dengue in Vietnamese Infants

    PubMed Central

    Bich Chau, Tran Nguyen; Anders, Katherine L.; Lien, Le Bich; Hung, Nguyen Thanh; Minh Hieu, Lu Thi; Tuan, Nguyen Minh; Thuy, Tran Thi; Phuong, Le Thi; Hong Tham, Nguyen Thi; Lanh, Mai Ngoc; Farrar, Jeremy J.; Whitehead, Stephen S.; Simmons, Cameron P.

    2010-01-01

    Background Infants account for a small proportion of the overall dengue case burden in endemic countries but can be clinically more difficult to manage. The clinical and laboratory features in infants with dengue have not been extensively characterised. Methodology/Principal Findings This prospective, cross-sectional descriptive study of infants hospitalized with dengue was conducted in Vietnam from November 2004 to December 2007. More than two-thirds of 303 infants enrolled on clinical suspicion of dengue had a serologically confirmed dengue virus (DENV) infection. Almost all were primary dengue infections and 80% of the infants developed DHF/DSS. At the time of presentation and during hospitalization, the clinical signs and symptoms in infants with dengue were difficult to distinguish from those with other febrile illnesses, suggesting that in infants early laboratory confirmation could assist appropriate management. Detection of plasma NS1 antigen was found to be a sensitive marker of acute dengue in infants with primary infection, especially in the first few days of illness. Conclusions/Significance Collectively, these results provide a systematic description of the clinical features of dengue in infants and highlight the value of NS1 detection for diagnosis. PMID:20405057

  7. Transverse Myelitis as an Unusual Complication of Dengue Fever.

    PubMed

    Mota, Mânlio Tasso de Oliveira; Estofolete, Cássia Fernanda; Zini, Nathalia; Terzian, Ana Carolina Bernardes; Gongora, Delzi Vinha Nunes; Maia, Irineu Luiz; Nogueira, Maurício Lacerda

    2017-02-08

    Dengue fever is the most common arbovirus disease, and presents with a large spectrum of clinical manifestations ranging from asymptomatic disease through to the development of dengue hemorrhagic fever. These extreme cases can lead to dengue shock syndrome, and sometimes death. Spinal cord involvement in dengue virus (DENV) infections is rare. Here, we report a case in which the patient developed acute transverse myelitis (TM) without paraparesis following a DENV infection. This case highlights the importance of physicians' awareness of the possible link between DENV and TM in endemic areas.

  8. Dengue fever in the San Juan Bay Estuary: Evaluating the ...

    EPA Pesticide Factsheets

    Dengue is transmitted by Aedes aegypti, a species that thrives in cities. Here we ask which elements within the urban environment could be managed to reduce the potential for Dengue occurrence. In particular, we study the potential of wetlands in the SJBE to buffer from vector proliferation. Wetlands provide ecosystem services such as heat and water hazard mitigation, water purification and habitat for a diversity of species, all of which are factors that have been shown to affect Dengue vectors. As such, we hypothesize that within coastal neighborhoods in the SJBE wetlands, ecosystem services lead to lower Dengue occurrence. We test this hypothesis using Dengue data from 2010-2013, which includes the largest epidemic in PR history. Our analytical model includes relevant socio-economic factors and environmental controls that may also affect Dengue dynamics. Results indicated a negative effect of neighborhood mangrove cover and a positive effect of percent flood area on Dengue prevalence. Moreover, heat hazards were positively correlated with dengue prevalence and negatively correlated with neighborhood mangrove cover. Dengue prevalence did not correlate with herbaceous wetlands, or with the ecosystem services of water quality or vertebrate species richness. Mosquito borne diseases are an increasingly important health concern, which pose great challenges for safe and sustainable control and eradication. This reality calls for management approaches that consider m

  9. Epidemiological trends of dengue in mainland China, 2005-2015.

    PubMed

    Sun, Jimin; Lu, Liang; Wu, Haixia; Yang, Jun; Xu, Lei; Sang, Shaowei; Liu, Qiyong

    2017-04-01

    To explore the epidemiological trend of dengue in mainland China. Data on dengue cases reported from 2005 to 2015 were collected, and epidemiological trends, including average age, occupation, seasonal distribution, and interval from illness onset to confirmation, were analyzed using SPSS 19.0 and R 3.1.1. A total of 59 334 dengue cases were recorded in China during the years 2005-2015. Most dengue cases occurred in individuals aged between 21 years and 50 years. Of note, the median age of dengue cases did not show a trend towards becoming younger; the median age was significantly older than that of cases in dengue endemic areas. The proportion of cases occurring during September and October was higher in 2012-2015 than in 2005-2011. The number of affected provinces ranged between 10 and 27 and the number of affected counties ranged between 42 and 415. The median time from illness onset to confirmation of dengue decreased sharply in 2015, indicating that comprehensive measures have been taken in mainland China. Although the number of dengue cases has increased and the affected areas have expanded in recent years, dengue is still an imported disease and does not present an endemic trend in mainland China. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  10. Antiviral activity of lanatoside C against dengue virus infection.

    PubMed

    Cheung, Yan Yi; Chen, Karen Caiyun; Chen, Huixin; Seng, Eng Khuan; Chu, Justin Jang Hann

    2014-11-01

    Dengue infection poses a serious threat globally due to its recent rapid spread and rise in incidence. Currently, there is no approved vaccine or effective antiviral drug for dengue virus infection. In response to the urgent need for the development of an effective antiviral for dengue virus, the US Drug Collection library was screened in this study to identify compounds with anti-dengue activities. Lanatoside C, an FDA approved cardiac glycoside was identified as a candidate anti-dengue compound. Our data revealed that lanatoside C has an IC50 of 0.19μM for dengue virus infection in HuH-7 cells. Dose-dependent reduction in dengue viral RNA and viral proteins synthesis were also observed upon treatment with increasing concentrations of lanatoside C. Time of addition study indicated that lanatoside C inhibits the early processes of the dengue virus replication cycle. Furthermore, lanatoside C can effectively inhibit all four serotypes of dengue virus, flavivirus Kunjin, alphavirus Chikungunya and Sindbis virus as well as the human enterovirus 71. These findings suggest that lanatoside C possesses broad spectrum antiviral activity against several groups of positive-sense RNA viruses.

  11. Infection risk to travelers going to dengue fever endemic regions.

    PubMed

    Pongsumpun, P; Patanarapelert, K; Sriprom, M; Varamit, S; Tang, I M

    2004-03-01

    The risk of dengue virus infection to travelers visiting dengue fever endemic regions was studied through the use of mathematical modeling. A Susceptible-Infected-Recovered (SIR) model is used to describe the transmission of dengue fever (DF) in an endemic region into which tourists enter. The dynamics of a new class of human, the traveler, is incorporated into the systems of first order differential equations in the SIR describing the dynamics of the transmission in the host region. Using standard dynamic analysis methods, the numbers of travelers who become infected with the dengue virus are calculated as a function of the length of time the tourist stays in the region.

  12. STUDIES UPON THE ETIOLOGY OF DENGUE FEVER

    PubMed Central

    Harris, William H.; Duval, Charles W.

    1924-01-01

    The dengue cases studied during this epidemic were, as a whole, typical examples of the disease. The onset was sudden, often of a violent character, ushered in with severe headache and backache, vague pains throughout the body, and fever ranging from 101–105°F. On the 2nd or 3rd day a maculopapular eruption appeared, generally on the neck, chest, and arms, but sometimes more widely disseminated. In most instances the fever remained for 3 or 4 days, after which it dropped to normal to rise again in 24 to 48 hours. The secondary rise, while occasionally higher than the primary one, was as a rule of a milder character. A few cases occurred in which marked jaundice existed. As reported for previous epidemics, no fatalities were recorded and hence no human material for histological study was available. Those cases caught in the fastigium of the disease were selected when possible as a source of material. The leucocytic count in all of the observed human cases was below normal. The experiments herein reported upon the transmission of dengue fever to the guinea pig are based upon the use of material secured from sixteen typical human cases of the disease, and upon the inoculation of many animals. Of the 143 animals used for the initial transmission, 42, representing eleven human cases out of the sixteen studied, reacted in a characteristic manner. The reaction occasioned in these animals by the inoculations closely resembles the symptoms seen in human dengue, differing only in the absence of exanthem. The primary pyrexia following regularly after a definite incubation period of 2 to 5 days, the secondary rise in temperature after a 24 to 48 hour remission ("saddleback"curve), and the concomitant fall in the circulating leucocytes present a syndrome identical with that of the human disease. Dark-field and special tinctorial studies of the dengue material, both human and experimental, have failed to reveal any visible spirochetal microorganism. It seems unlikely that an

  13. Safety Testing of Dengue-1 and Dengue-3 Seeds for Human Challenges, Unattenuated; Hepatitis A Virus, Strain HM-175

    DTIC Science & Technology

    1989-03-21

    Frederick, Maryland 21701-5012 ELEMENT NO. NO. 3M1- NO.N. I62770A 162770A870 I AC 029 (U) Safety Testing of Dengue -1 and Dengue -3 Seeds for Human...Conwu on F~vwn it Rtconat and .ewoy by block IIUW*bS)r FIELD GROUP SUl.GROUP 06 13 -- i engue-l; Dengue -3; Hepatitis A; Viral seeds; Vacn-,1A 19. ABSTRACT

  14. Vector dynamics and transmission of dengue virus: implications for dengue surveillance and prevention strategies: vector dynamics and dengue prevention.

    PubMed

    Scott, Thomas W; Morrison, Amy C

    2010-01-01

    Accounting for variation in mosquito vector populations will improve dengue surveillance and prevention. Because Aedes aegypti, the principle dengue virus (DENV) vector, transmit the virus with remarkable efficiency, entomological thresholds are especially low. Assessing risk of human infection based on immature mosquito indices has proven difficult. Greater emphasis should be placed on relative abundance of adult vectors in relation to human serotype-specific herd immunity, introduction of unique viruses, mosquito-human contact and weather. The most appropriate spatial scale for assessing entomological risk is the individual household. The scale for measuring DENV transmission risk has yet to be determined but is clearly larger than the household and likely to exceed several city blocks. Because households are expected to be a primary site for human DENV infection, intradomicile vector control strategies should be a priority, especially when the force of transmission is high. The most effective intervention strategy will combine vector control with vaccine delivery for rapid and sustained disease prevention.

  15. Acute Renal Failure in Dengue Infection

    PubMed Central

    Subramanyam, Nambakam Tanuja

    2017-01-01

    Introduction Acute Renal Failure (RF) is a rare but well recognized complication of Dengue Infection (DI). There has been paucity of published data regarding renal involvement in DI. Aim The aim of the present study was to elucidate different clinical presentations, disease outcomes of DI. To study the frequency, severity and predictors of RF in DI. Materials and Methods Patients diagnosed either as Dengue Fever (DF) or Dengue Haemorrhagic Fever/Dengue Shock Syndrome (DHF/DSS) respectively were enrolled for this study. The diagnostic criteria for DI were febrile illness associated with one of the following: 1) detection of dengue-specific IgM capture antibody or Non-Structural Protein1 (NS1) antigen; or 2) a four-fold or greater increase of dengue-specific IgG capture antibody by ELISA and haemoagglutination inhibition assay. Patients were diagnosed as having Acute RF, if serum creatinine was >1.2 mg/dl or who showed improvement by 50% in serum creatinine from the initial value. It is an observational study of medical charts, data of age, gender, and medical history of any underlying diseases in association with the severity of DI of each patient recorded. All of the laboratory results were collected. Parameters that influenced the clinical presentations and outcomes for development of classical DF or DHF/DSS in patients with or without RF were analysed and compared. Descriptive and inferential statistical analysis was carried. The Statistical software namely SAS 9.2, SPSS 15.0, Stata 10.1, Med Calc 9.0.1, Systat 12.0 and R environment ver.2.11.1 were used. Results Most common symptoms were fever followed by headache and pain in abdomen. Among the patients with RF, all patients had recovery. The patients with DHF/DSS were more susceptible to develop renal failure compared to DF group. There were statistically significant higher frequencies of renal failure, haemoconcentration, thrombocytopenia, low serum cholesterol. Patients in the RF group also had significantly

  16. Epidemiological features of dengue and chikungunya infections in Burma.

    PubMed

    Thaung, U; Ming, C K; Swe, T; Thein, S

    1975-06-01

    A serological survey for antibody to dengue and chikungunya was carried out in all 14 divisions and states and 2 border towns in Burma during 1973-74. Dengue HI antibody prevalence rate of less than 10% was observed in Arakan and Shan States, 10 to 30% in the Irrawaddy, Pegu, Mandalay Divisions and Kachin, Mon and Karen States, 31 to 60% in Sagaing Division, and over 60% in Rangoon, Magwe and Tenasserim Divisions. Similarly, chikungunya HI antibody prevalence rate of less than 10% was observed in Arakan State, 10 to 30% in the Irrawaddy, Pegu, Mandalay and Sagaing Divisions and Kachin State, 31 to 60% in Rangoon Division and Mon State. Both dengue and chikungunya antibodies were detected where Aedes aegypti mosquitoes were prevalent but the antibody prevalent rates were not directly proportional to the premises index. No HI antibody to dengue nor chikungunya was detected in Aedes aegypti free hilly areas, Chin and Kayah States, but was detected in the Shan State, Dengue and chikungunya infections were observed both in rural and urban populations. Dengue and chikungunya infections affected all socioeconomic classes in Rangoon equally but in Mandalay high socioeconomic class was nearly 3 times less affected than lower socioeconomic class. The infrequencies of dengue and chikungunya infections were observed to be 2 to 3 times higher in residents of Rangoon City than those of other towns. In Rangoon the antibody prevalence rates to dengue increased progressively with age while in other towns no appreciable increase in rates with age was observed. Both sexes were equally affected. This study provides strong circumstantial evidence that dengue and chikungunya viruses are highly and widely distributed throughout Burma, and that new outbreaks of haemorrhagic fever could occur in previously free areas following introduction of dengue viruses into populations previously exposed to one type of dengue.

  17. Interferon-γ-induced protein 10 in Dengue Virus infection.

    PubMed

    Fallahi, P; Elia, G

    2016-01-01

    Dengue virus (DENV) infection causes dengue fever, dengue hemorrhagic fever, or dengue shock syndrome. Interferons (IFNs), and IFN-γ dependent chemokines, chemokine (C-X-C motif) ligand (CXCL)10/IFN-γ-induced protein 10 (IP-10), CXCL9/MIG and CXCL11/I-TAC, and their common receptor chemokine (C-X-C motif) receptor (CXCR)3 are induced by DENV infection; however it has been shown that the latter two could not compensate for the absence of IP-10. This paper reviews studies about DENV and IP-10. Evidences show the importance of IP-10 induction during DENV infection, in macrophages, lymphocytes, hepatic cells, denritic cells, in skin and in the brain. Furthermore it has been shown that chemokines IP-10, I-TAC and their receptor CXCR3 are involved in severity of dengue; in fact, pulmonary effusion or ascites, painful hepatomegaly or aspartate aminotransferase increase, are correlated with IP-10 levels. It has been also demonstrated that IP-10 was more elevated in subjects who subsequently developed dengue hemorrhagic fever or dengue shock syndrome. It has been also shown that IP-10 has a direct action in control of dengue viral replication. Furthermore IP-10 circulating levels may be used to discriminate dengue fever from other febbrile diseases. This is of particular importance in certain situations, for example to discriminate occupationally acquired dengue, in patients with febbrile disorders coming from endemic countries. These studies suggested that these chemokines can be used as potential biomarkers for differential diagnosis and the disease progression, while others can be used to control dengue viral replication, thus representing a viable targets for drug therapy.

  18. A predictive model to differentiate dengue from other febrile illness.

    PubMed

    Fernández, Eduardo; Smieja, Marek; Walter, Stephen D; Loeb, Mark

    2016-11-22

    Dengue is a major public health problem in tropical and subtropical countries and has a presentation similar to other febrile illnesses. Since laboratory confirmation is frequently delayed, the majority of dengue cases are diagnosed based on symptoms. The objective of this study was to identify clinical, hematological and demographical parameters that could be used as predictors of dengue fever among patients with febrile illness. We conducted a retrospective cohort study of 548 patients presenting with febrile syndrome to the largest public hospitals in Honduras. Patients' clinical, laboratory, and demographic data as well as dengue laboratory detection by either serology or viral isolation were used to build a predictive statistical model to identify dengue cases. Of 548 patients, 390 were confirmed with dengue infection while 158 had negative results. Univariable analysis revealed seven variables associated with dengue: male sex, petechiae, skin rash, myalgia, retro-ocular pain, positive tourniquet test, and gingival bleeding. In multivariable logistic regression analysis, retro-ocular pain petechiae and gingival bleeding were associated with increased risk, while epistaxis and paleness of skin were associated with reduced risk of dengue. Using a value of 0.6 (i.e., 60% probability for a case to be positive based on the equation values), our model had a sensitivity of 86.2%, a specificity of 27.2%, and an overall accuracy of 69.2%; allowing for the diagnosis of dengue to be ruled out and for other febrile conditions to be investigated. Among Honduran patients presenting with febrile illness, our analysis identified key symptoms associated with dengue fever, however the overall accuracy of our model was still low and specificity remains a concern. Our model requires validation in other populations with a similar pattern of dengue transmission.

  19. Invariant NKT Cell Response to Dengue Virus Infection in Human

    PubMed Central

    Matangkasombut, Ponpan; Chan-in, Wilawan; Opasawaschai, Anunya; Pongchaikul, Pisut; Tangthawornchaikul, Nattaya; Vasanawathana, Sirijitt; Limpitikul, Wannee; Malasit, Prida; Duangchinda, Thaneeya; Screaton, Gavin; Mongkolsapaya, Juthathip

    2014-01-01

    Background Dengue viral infection is a global health threat without vaccine or specific treatment. The clinical outcome varies from asymptomatic, mild dengue fever (DF) to severe dengue hemorrhagic fever (DHF). While adaptive immune responses were found to be detrimental in the dengue pathogenesis, the roles of earlier innate events remain largely uninvestigated. Invariant natural killer T (iNKT) cells represent innate-like T cells that could dictate subsequent adaptive response but their role in human dengue virus infection is not known. We hypothesized that iNKT cells play a role in human dengue infection. Methods Blood samples from a well-characterized cohort of children with DF, DHF, in comparison to non-dengue febrile illness (OFI) and healthy controls at various time points were studied. iNKT cells activation were analyzed by the expression of CD69 by flow cytometry. Their cytokine production was then analyzed after α-GalCer stimulation. Further, the CD1d expression on monocytes, and CD69 expression on conventional T cells were measured. Results iNKT cells were activated during acute dengue infection. The level of iNKT cell activation associates with the disease severity. Furthermore, these iNKT cells had altered functional response to subsequent ex vivo stimulation with α-GalCer. Moreover, during acute dengue infection, monocytic CD1d expression was also upregulated and conventional T cells also became activated. Conclusion iNKT cells might play an early and critical role in the pathogenesis of severe dengue viral infection in human. Targeting iNKT cells and CD1d serve as a potential therapeutic strategy for severe dengue infection in the future. PMID:24945350

  20. Dengue NS1 and prM antibodies increase the sensitivity of acute dengue diagnosis test and differentiate from Japanese encephalitis infection.

    PubMed

    Gowri Sankar, S; Balaji, T; Venkatasubramani, K; Thenmozhi, V; Dhananjeyan, K J; Paramasivan, R; Tyagi, B K; John Vennison, S

    2014-05-01

    Accurate and early diagnosis of dengue infection is essential for dengue case management. In outbreak conditions, it is essential to include two different tests to diagnose dengue and the choice depends on the number of days after the onset of illness in which the sample is collected. During the laboratory diagnosis of dengue in late acute and convalescent phase by MAC-ELISA, it is necessary to rule out possible cross reactions of closely related flavivirus, such as Japanese encephalitis virus which is commonly co-circulating. In the present investigation, the usefulness of dengue virus NS1 and prM antibodies in diagnosing and differentiating dengue from Japanese encephalitis infection was assessed using samples collected during out-breaks. It was shown here that, detection of antibodies against dengue NS1 and prM proteins increases the sensitivity of dengue diagnosis until 15days. Moreover, detection of antibodies against both proteins was able to differentiate dengue from Japanese encephalitis infection.

  1. Asymptomatic humans transmit dengue virus to mosquitoes

    PubMed Central

    Duong, Veasna; Lambrechts, Louis; Paul, Richard E.; Ly, Sowath; Lay, Rath Srey; Long, Kanya C.; Huy, Rekol; Tarantola, Arnaud; Scott, Thomas W.; Sakuntabhai, Anavaj; Buchy, Philippe

    2015-01-01

    Three-quarters of the estimated 390 million dengue virus (DENV) infections each year are clinically inapparent. People with inapparent dengue virus infections are generally considered dead-end hosts for transmission because they do not reach sufficiently high viremia levels to infect mosquitoes. Here, we show that, despite their lower average level of viremia, asymptomatic people can be infectious to mosquitoes. Moreover, at a given level of viremia, DENV-infected people with no detectable symptoms or before the onset of symptoms are significantly more infectious to mosquitoes than people with symptomatic infections. Because DENV viremic people without clinical symptoms may be exposed to more mosquitoes through their undisrupted daily routines than sick people and represent the bulk of DENV infections, our data indicate that they have the potential to contribute significantly more to virus transmission to mosquitoes than previously recognized. PMID:26553981

  2. The Medicinal Chemistry of Dengue Virus.

    PubMed

    Behnam, Mira A M; Nitsche, Christoph; Boldescu, Veaceslav; Klein, Christian D

    2016-06-23

    The dengue virus and related flaviviruses are an increasing global health threat. In this perspective, we comment on and review medicinal chemistry efforts aimed at the prevention or treatment of dengue infections. We include target-based approaches aimed at viral or host factors and results from phenotypic screenings in cellular assay systems for viral replication. This perspective is limited to the discussion of results that provide explicit chemistry or structure-activity relationship (SAR), or appear to be of particular interest to the medicinal chemist for other reasons. The discovery and development efforts discussed here may at least partially be extrapolated toward other emerging flaviviral infections, such as West Nile virus. Therefore, this perspective, although not aimed at flaviviruses in general, should also be able to provide an overview of the medicinal chemistry of these closely related infectious agents.

  3. Texas Lifestyle Limits Transmission of Dengue Virus

    PubMed Central

    Lathrop, Sarah; Bunning, Michel; Biggerstaff, Brad; Singer, Daniel; Tiwari, Tejpratap; Baber, Laura; Amador, Manuel; Thirion, Jaime; Hayes, Jack; Seca, Calixto; Mendez, Jorge; Ramirez, Bernardo; Robinson, Jerome; Rawlings, Julie; Vorndam, Vance; Waterman, Stephen; Gubler, Duane; Clark, Gary; Hayes, Edward

    2003-01-01

    Urban dengue is common in most countries of the Americas, but has been rare in the United States for more than half a century. In 1999 we investigated an outbreak of the disease that affected Nuevo Laredo, Tamaulipas, Mexico, and Laredo, Texas, United States, contiguous cities that straddle the international border. The incidence of recent cases, indicated by immunoglobulin M antibody serosurvey, was higher in Nuevo Laredo, although the vector, Aedes aegypti, was more abundant in Laredo. Environmental factors that affect contact with mosquitoes, such as air-conditioning and human behavior, appear to account for this paradox. We conclude that the low prevalence of dengue in the United States is primarily due to economic, rather than climatic, factors. PMID:12533286

  4. Costs of dengue prevention and incremental cost of dengue outbreak control in Guantanamo, Cuba.

    PubMed

    Baly, Alberto; Toledo, Maria E; Rodriguez, Karina; Benitez, Juan R; Rodriguez, Maritza; Boelaert, Marleen; Vanlerberghe, Veerle; Van der Stuyft, Patrick

    2012-01-01

    To assess the economic cost of routine Aedes aegypti control in an at-risk environment without dengue endemicity and the incremental costs incurred during a sporadic outbreak. The study was conducted in 2006 in the city of Guantanamo, Cuba. We took a societal perspective to calculate costs in months without dengue transmission (January-July) and during an outbreak (August-December). Data sources were bookkeeping records, direct observations and interviews. The total economic cost per inhabitant (p.i.) per month. (p.m.) increased from 2.76 USD in months without dengue transmission to 6.05 USD during an outbreak. In months without transmission, the routine Aedes control programme cost 1.67 USD p.i. p.m. Incremental costs during the outbreak were mainly incurred by the population and the primary/secondary level of the healthcare system, hardly by the vector control programme (1.64, 1.44 and 0.21 UDS increment p.i. p.m., respectively). The total cost for managing a hospitalized suspected dengue case was 296.60 USD (62.0% direct medical, 9.0% direct non-medical and 29.0% indirect costs). In both periods, the main cost drivers for the Aedes control programme, the healthcare system and the community were the value of personnel and volunteer time or productivity losses. Intensive efforts to keep A. aegypti infestation low entail important economic costs for society. When a dengue outbreak does occur eventually, costs increase sharply. In-depth studies should assess which mix of activities and actors could maximize the effectiveness and cost-effectiveness of routine Aedes control and dengue prevention. © 2011 Blackwell Publishing Ltd.

  5. First Experimental In Vivo Model of Enhanced Dengue Disease Severity through Maternally Acquired Heterotypic Dengue Antibodies

    PubMed Central

    Ng, Jowin Kai Wei; Zhang, Summer Lixin; Tan, Hwee Cheng; Yan, Benedict; Maria Martinez Gomez, Julia; Tan, Wei Yu; Lam, Jian Hang; Tan, Grace Kai Xin; Ooi, Eng Eong; Alonso, Sylvie

    2014-01-01

    Dengue (DEN) represents the most serious arthropod-borne viral disease. DEN clinical manifestations range from mild febrile illness to life-threatening hemorrhage and vascular leakage. Early epidemiological observations reported that infants born to DEN-immune mothers were at greater risk to develop the severe forms of the disease upon infection with any serotype of dengue virus (DENV). From these observations emerged the hypothesis of antibody-dependent enhancement (ADE) of disease severity, whereby maternally acquired anti-DENV antibodies cross-react but fail to neutralize DENV particles, resulting in higher viremia that correlates with increased disease severity. Although in vitro and in vivo experimental set ups have indirectly supported the ADE hypothesis, direct experimental evidence has been missing. Furthermore, a recent epidemiological study has challenged the influence of maternal antibodies in disease outcome. Here we have developed a mouse model of ADE where DENV2 infection of young mice born to DENV1-immune mothers led to earlier death which correlated with higher viremia and increased vascular leakage compared to DENV2-infected mice born to dengue naïve mothers. In this ADE model we demonstrated the role of TNF-α in DEN-induced vascular leakage. Furthermore, upon infection with an attenuated DENV2 mutant strain, mice born to DENV1-immune mothers developed lethal disease accompanied by vascular leakage whereas infected mice born to dengue naïve mothers did no display any clinical manifestation. In vitro ELISA and ADE assays confirmed the cross-reactive and enhancing properties towards DENV2 of the serum from mice born to DENV1-immune mothers. Lastly, age-dependent susceptibility to disease enhancement was observed in mice born to DENV1-immune mothers, thus reproducing epidemiological observations. Overall, this work provides direct in vivo demonstration of the role of maternally acquired heterotypic dengue antibodies in the enhancement of dengue

  6. Dengue infection in neotropical forest mammals.

    PubMed

    de Thoisy, Benoît; Lacoste, Vincent; Germain, Adeline; Muñoz-Jordán, Jorge; Colón, Candimar; Mauffrey, Jean-François; Delaval, Marguerite; Catzeflis, François; Kazanji, Mirdad; Matheus, Séverine; Dussart, Philippe; Morvan, Jacques; Setién, Alvaro Aguilar; Deparis, Xavier; Lavergne, Anne

    2009-04-01

    In South America, dengue is the arbovirus-transmitted disease with the highest incidence. Unlike other arboviruses, wild mammals have no confirmed role in the cycle of dengue in the neotropics, although serological studies have suggested a possible secondary amplification cycle involving mammals other than nonhuman primates. In French Guiana, where all four serotypes (DENV-1, DENV-2, DENV-3, DENV-4) are present, the disease is endemic with outbreak events. To determine whether wild mammals can be infected by DENV, rodents, marsupials, and bats were captured over several periods, from 2001 to 2007, at two sites. The first location is a secondary forest surrounded by an urban area where dengue is endemic. The second location is a forest edge site where the disease has not yet emerged. A total of 10,000 trap-nights were performed and 616 mammals were captured. RNAs representing the four DENV serotypes were detected at both sites by reverse-transcriptase polymerase chain reaction in the livers and/or sera of 92 mammals belonging to 14 out of 32 species distributed among all the orders investigated: Rodentia (33 positive/146 tested), Marsupialia (40/318), and Chiroptera (19/152). Sequence analyses of a portion of the capsid and premembrane junction revealed that mammal strains of DENV-1, DENV-2, DENV-3, and DENV-4 had only 92.6%, 89%, 95%, and 95.8% identity, respectively, with strains circulating in the human population during the same periods. Regarding DENV-2, strains related (99% identity) to those responsible for an epidemic event in humans in French Guiana concurrent to the capture sessions were also evidenced, suggesting that wild mammals in edge habitats can be infected by circulating human strains. Our results demonstrate, for the first time, that neotropical wild mammals can be infected with dengue virus. The question of whether mammals maintain DENV in enzootic cycles and can play a role in its reemergence in human populations remains to be answered.

  7. Dengue: recent past and future threats

    PubMed Central

    Rogers, David J.

    2015-01-01

    This article explores four key questions about statistical models developed to describe the recent past and future of vector-borne diseases, with special emphasis on dengue: (1) How many variables should be used to make predictions about the future of vector-borne diseases?(2) Is the spatial resolution of a climate dataset an important determinant of model accuracy?(3) Does inclusion of the future distributions of vectors affect predictions of the futures of the diseases they transmit?(4) Which are the key predictor variables involved in determining the distributions of vector-borne diseases in the present and future?Examples are given of dengue models using one, five or 10 meteorological variables and at spatial resolutions of from one-sixth to two degrees. Model accuracy is improved with a greater number of descriptor variables, but is surprisingly unaffected by the spatial resolution of the data. Dengue models with a reduced set of climate variables derived from the HadCM3 global circulation model predictions for the 1980s are improved when risk maps for dengue's two main vectors (Aedes aegypti and Aedes albopictus) are also included as predictor variables; disease and vector models are projected into the future using the global circulation model predictions for the 2020s, 2040s and 2080s. The Garthwaite–Koch corr-max transformation is presented as a novel way of showing the relative contribution of each of the input predictor variables to the map predictions. PMID:25688021

  8. Idiopathic purpura fulminans in dengue hemorrhagic fever.

    PubMed

    Karunatilaka, D H; De Silva, J R S; Ranatunga, P K; Gunasekara, T Mr; Faizal, M Am; Malavige, G N

    2007-08-01

    Purpura fulminans is a rapidly progressive thrombotic disease that has been described during both severe bacterial and viral infections. Disseminated intravascular coagulation (DIC), antiphospholipid antibodies and acquired or congenital C and S protein deficiency are thought to play a role in its pathogenesis. Here we report the case of a 4-year-old girl who developed gangrene of all her fingers and toes following dengue shock syndrome complicated by DIC and also discuss its management.

  9. Pathogenesis of Dengue Vaccine Viruses in Mosquitoes.

    DTIC Science & Technology

    1982-07-01

    Aedes aegyti mosquitoes. The vaccine virus was markedly less efficient in its ability to infect mosquitoes orally. After ingesting infectious bloodmeals... Aedes aepypti mosquitoes. The vaccine virus was markedly less efficient iFn its ability to infect mosquitoes orally. After ingesting infectious...transmission potential of dengue-2 parent and candidate vaccine viruses in Aedes aegypti and Aedes albopictus mosquitoes. Both strains were capable of

  10. Enhanced performance of an innovative dengue IgG/IgM rapid diagnostic test using an anti-dengue EDI monoclonal antibody and dengue virus antigen

    PubMed Central

    Lee, Jihoo; Kim, Young-Eun; Kim, Hak-Yong; Sinniah, Mangalam; Chong, Chom-Kyu; Song, Hyun-Ok

    2015-01-01

    High levels of anti-dengue IgM or IgG can be detected using numerous rapid diagnostic tests (RDTs). However, the sensitivity and specificity of these tests are reduced by changes in envelope glycoprotein antigenicity that inevitably occur in limited expression systems. A novel RDT was designed to enhance diagnostic sensitivity. Dengue viruses cultured in animal cells were used as antigens to retain the native viral coat protein. Monoclonal antibodies (mAbs) were then developed, for the first time, against domain I of envelope glycoprotein (EDI). The anti-dengue EDI mAb was employed as a capturer, and EDII and EDIII, which are mainly involved in the induction of neutralizing antibodies in patients, were fully available to bind to anti-dengue IgM or IgG in patients. A one-way automatic blood separation device prevented reverse migration of plasma and maximize the capture of anti-dengue antibodies at the test lines. A clinical evaluation in the field proved that the novel RDT (sensitivities of 96.5% and 96.7% for anti-dengue IgM and IgG) is more effective in detecting anti-dengue antibodies than two major commercial tests (sensitivities of 54.8% and 82% for SD BIOLINE; 50.4% and 75.3% for PanBio). The innovative format of RDT can be applied to other infectious viral diseases. PMID:26655854

  11. Dengue in Malaysia: Factors Associated with Dengue Mortality from a National Registry.

    PubMed

    Liew, Su May; Khoo, Ee Ming; Ho, Bee Kiau; Lee, Yew Kong; Omar, Mimi; Ayadurai, Vickneswari; Mohamed Yusoff, Fazlina; Suli, Zailiza; Mudin, Rose Nani; Goh, Pik Pin; Chinna, Karuthan

    2016-01-01

    The increasing incidence and geographical distribution of dengue has had significant impact on global healthcare services and resources. This study aimed to determine the factors associated with dengue-related mortality in a cohort of Malaysian patients. This was a retrospective cohort study of patients in the Malaysian National Dengue Registry of 2013. The outcome measure was dengue-related mortality. Associations between sociodemographic and clinical variables with the outcome were analysed using multivariate analysis. There were 43 347 cases of which 13081 were serologically confirmed. The mean age was 30.0 years (SD 15.7); 60.2% were male. The incidence of dengue increased towards the later part of the calendar year. There were 92 probable dengue mortalities, of which 41 were serologically confirmed. Multivariate analysis in those with positive serology showed that increasing age (OR 1.03; CI:1.01-1.05), persistent vomiting (OR 13.34; CI: 1.92-92.95), bleeding (OR 5.84; CI 2.17-15.70) and severe plasma leakage (OR 66.68; CI: 9.13-487.23) were associated with mortality. Factors associated with probable dengue mortality were increasing age (OR 1.04; CI:1.03-1.06), female gender (OR 1.53; CI:1.01-2.33), nausea and/or vomiting (OR 1.80; CI:1.17-2.77), bleeding (OR 3.01; CI:1.29-7.04), lethargy and/or restlessness (OR 5.97; CI:2.26-15.78), severe plasma leakage (OR 14.72; CI:1.54-140.70), and shock (OR 1805.37; CI:125.44-25982.98), in the overall study population. Older persons and those with persistent vomiting, bleeding or severe plasma leakage, which were associated with mortality, at notification should be monitored closely and referred early if indicated. Doctors and primary care practitioners need to detect patients with dengue early before they develop these severe signs and symptoms.

  12. Genetic elimination of dengue vector mosquitoes.

    PubMed

    Wise de Valdez, Megan R; Nimmo, Derric; Betz, John; Gong, Hong-Fei; James, Anthony A; Alphey, Luke; Black, William C

    2011-03-22

    An approach based on mosquitoes carrying a conditional dominant lethal gene (release of insects carrying a dominant lethal, RIDL) is being developed to control the transmission of dengue viruses by vector population suppression. A transgenic strain, designated OX3604C, of the major dengue vector, Aedes aegypti, was engineered to have a repressible female-specific flightless phenotype. This strain circumvents the need for radiation-induced sterilization, allows genetic sexing resulting in male-only releases, and permits the release of eggs instead of adult mosquitoes. OX3604C males introduced weekly into large laboratory cages containing stable target mosquito populations at initial ratios of 8.5-101 OX3604Ctarget eliminated the populations within 10-20 weeks. These data support the further testing of this strain in contained or confined field trials to evaluate mating competitiveness and environmental and other effects. Successful completion of the field trials should facilitate incorporation of this approach into area-wide dengue control or elimination efforts as a component of an integrated vector management strategy.

  13. Pharmacological intervention for dengue virus infection.

    PubMed

    Lai, Jenn-Haung; Lin, Yi-Ling; Hsieh, Shie-Liang

    2017-04-01

    Dengue virus (DENV) infection has a considerable health impact in tropical and subtropical countries worldwide. Escalation of infection rates greatly increases morbidity and mortality, most commonly from deaths due to dengue hemorrhagic fever and dengue shock syndrome. Although the development of an effective, long-lasting vaccine has been a major aim for control and prevention of DENV infection, the currently licensed vaccine has limitations and is less than satisfactory. Thus, there remains an important need to identify effective and tolerable medications for treatment of DENV-infected patients both in the early phase, to prevent progression to fatal outcomes, and to minimize deaths after patients develop severe complications. This review will address several specific points, including (1) approaches to identify anti-DENV medications, (2) recent advances in the development of potential compounds targeting DENV infection, (3) experience with clinical trials of regimens for DENV infection, (4) some available medications of potential for clinical trials against DENV infection, (5) reasons for unsuccessful outcomes and challenges of anti-DENV treatments, and (6) directions for developing or selecting better anti-DENV strategies. This review provides useful guidance for clinicians selecting drugs for DENV-infected patients with severe manifestations or potential fatal disease progression, and for basic researchers seeking to develop effective anti-DENV regimens. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Ecological and immunological determinants of dengue epidemics

    PubMed Central

    Wearing, Helen J.; Rohani, Pejman

    2006-01-01

    The management of infectious diseases is an increasingly important public health issue, the effective implementation of which is often complicated by difficulties in teasing apart the relative roles of extrinsic and intrinsic factors influencing transmission. Dengue, a vector-borne strain polymorphic disease, is one such infection where transmission dynamics are affected by environmental variables as well as immune-mediated serotype interactions. To understand how alternative hypotheses concerning dengue infection and transmission may explain observed multiannual cycles in disease incidence, we adopt a theoretical approach that combines both ecological and immunological mechanisms. We demonstrate that, contrary to perceived wisdom, patterns generated solely by antibody-dependent enhancement or heterogeneity in virus virulence are not consistent with serotype-specific notification data in important ways. Furthermore, to generate epidemics with the characteristic signatures observed in data, we find that a combination of seasonal variation in vector demography and, crucially, a short-lived period of cross-immunity is sufficient. We then show how understanding the persistence and eradication of dengue serotypes critically depends on the alternative assumed mechanisms. PMID:16868086

  15. Severe Plasmodium knowlesi with dengue coinfection.

    PubMed

    Che Rahim, Mohd Jazman; Mohammad, Nurashikin; Besari, Alwi Muhd; Wan Ghazali, Wan Syamimee

    2017-02-20

    We report a case of severe Plasmodium knowlesi and dengue coinfection in a previously healthy 59-year-old Malay man who presented with worsening shortness of breath, high-grade fever with chills and rigors, dry cough, myalgia, arthralgia, chest discomfort and poor appetite of 1 week duration. There was a history mosquito fogging around his neighbourhood in his hometown. Further history revealed that he went to a forest in Jeli (northern part of Kelantan) 3 weeks prior to the event. Initially he was treated as severe dengue with plasma leakage complicated with type 1 respiratory failure as evidenced by positive serum NS1-antigen and thrombocytopenia. Blood for malarial parasite (BFMP) was sent for test as there was suspicion of malaria due to persistent thrombocytopenia despite recovering from dengue infection and the presence of a risk factor. The test revealed high count of malaria parasite. Confirmatory PCR identified the parasite to be Plasmodium knowlesi Intravenous artesunate was administered to the patient immediately after acquiring the BFMP result. Severe malaria was complicated with acute kidney injury and septicaemic shock. Fortunately the patient made full recovery and was discharged from the ward after 2 weeks of hospitalisation. 2017 BMJ Publishing Group Ltd.

  16. [Dengue fever: from disease to vaccination].

    PubMed

    Teyssou, R

    2009-08-01

    Dengue is a tropical disease affecting 110 countries throughout the world and placing over 3 billion people at risk of infection. According the World Health Organization 70 to 500 million persons are infected every year including 2 million who develop hemorrhagic form and 20,000 who die. Children are at highest risk for death. Due to the absence of specialized laboratories in most endemic regions and to the lack of specifici clinical presentation, the incidence of dengue and its economic costs are certainly underestimated. Dengue iscaused by an arbovirus belonging to the Flavivirus genus of the family Flaviviridae. There are four dengue virus serotypes and no cross protection between them. The disease is transmitted through the bites of mosquitoes belonging to the Aedes genus, mainly Aedes aegypti. However A. albopictus has played an important role in the spread of the disease and other species may be involved in specific locations (e.g., A. polynesiensis in the South Pacific). There is no specific treatment for dengue. Management of severe forms depends on symptomatic treatment of hemorrhagic complications and hypovolemic shock. Prevention requires control of vector mosquitoes that is difficult to implement and maintain. Dengue is a major emerging infectious disease with a heavy impact on public health. The high human and economic costs as well as the absence of specific preventive measures underscore the need to develop a vaccine. However finding and distributing such a vaccine to populations at risk is hampered by numerous obstacles. The most notable challenges standing in the way of development of a candidate vaccine are as follows: absence of an animal model, which has important implications for the preclinical development strategy; need to develop a live attenuated vaccine; existence of 4 antigenically distinct serotypes with the resulting risk of competition between vaccine strains; immunologic risks related to antibody-dependent enhancement that has been

  17. Primary dengue fever associated with hemophagocytic syndrome: a report of three imported cases, Bordeaux, France.

    PubMed

    Ribeiro, Emmanuel; Kassab, Somar; Pistone, Thierry; Receveur, Marie-Catherine; Fialon, Pierre; Malvy, Denis

    2014-01-01

    The dengue virus is responsible for a wide range of symptoms that can be classified into two distinct syndromes: classical dengue fever and severe dengue fever. Among the complicating forms, hemophagocytic syndrome (HPS) has been previously reported in case series of patients with secondary dengue fever outside of endemic settings. Of note, the occurrence of HPS has not yet been included among the criteria for defining severe dengue fever. We herein present three patients with HPS related to confirmed primary dengue virus infection. Clinicians should therefore consider hemophagocytosis as a complication during severe dengue infection in naïve patients.

  18. Clinical predictors of dengue fever co-infected with leptospirosis among patients admitted for dengue fever - a pilot study.

    PubMed

    Suppiah, Jeyanthi; Chan, Shie-Yien; Ng, Min-Wern; Khaw, Yam-Sim; Ching, Siew-Mooi; Mat-Nor, Lailatul Akmar; Ahmad-Najimudin, Naematul Ain; Chee, Hui-Yee

    2017-06-28

    Dengue and leptospirosis infections are currently two major endemics in Malaysia. Owing to the overlapping clinical symptoms between both the diseases, frequent misdiagnosis and confusion of treatment occurs. As a solution, the present work initiated a pilot study to investigate the incidence related to co-infection of leptospirosis among dengue patients. This enables the identification of more parameters to predict the occurrence of co-infection. Two hundred sixty eight serum specimens collected from patients that were diagnosed for dengue fever were confirmed for dengue virus serotyping by real-time polymerase chain reaction. Clinical, laboratory and demographic data were extracted from the hospital database to identify patients with confirmed leptospirosis infection among the dengue patients. Thus, frequency of co-infection was calculated and association of the dataset with dengue-leptospirosis co-infection was statistically determined. The frequency of dengue co-infection with leptospirosis was 4.1%. Male has higher preponderance of developing the co-infection and end result of shock as clinical symptom is more likely present among co-infected cases. It is also noteworthy that, DENV 1 is the common dengue serotype among all cases identified as dengue-leptospirosis co-infection in this study. The increasing incidence of leptospirosis among dengue infected patients has posed the need to precisely identify the presence of co-infection for the betterment of treatment without mistakenly ruling out either one of them. Thus, anticipating the possible clinical symptoms and laboratory results of dengue-leptospirosis co-infection is essential.

  19. The immunogenicity of tetravalent dengue DNA vaccine in mice pre-exposed to Japanese encephalitis or Dengue virus antigens.

    PubMed

    Prompetchara, Eakachai; Ketloy, Chutitorn; Keelapang, Poonsook; Sittisombut, Nopporn; Ruxrungtham, Kiat

    2015-09-01

    Asian countries are an endemic area for both dengue (DENV) and Japanese encephalitis viruses (JEV). While JEV vaccines have been used extensively in this region, DENV vaccines remains under development. Whether preexisting naturally acquired or vaccination-induced immunity against JEV may affect the immune response to dengue vaccine candidate is unclear. In this study we used mice previously immunized with JEV vaccines to evaluate the impact on dengue-specific neutralizing antibody responses to a tetravalent dengue DNA vaccine candidate (TDNA). A tetravalent cocktail of plasmids encoding pre-membrane and envelope proteins from each dengue serotype was administered into mice which had been previously primed with inactivated or live-attenuated JEV vaccines, or dengue serotype2 virus (DENV-2). Neutralizing antibody response was measured employing a plaque reduction neutralization test at two weeks after the priming and at four weeks after the second dose of the dengue tetravalent plasmids. Inactivated or live-attenuated JEV vaccines, or DENV-2 induced low levels of neutralizing antibodies against the homologous viruses (JE and dengue virus, respectively). DENV-2 injection induced also low levels of cross-reactive antibodies against DENV-1, -3 and -4. JEV vaccines have no effect on the dengue-specific neutralizing antibody responses to the subsequent TDNA immunization. Pre-exposure to DENV-2 infection increased DENV-2 specific response neutralizing antibody to two doses of TDNA plasmids by six folds, but did not affect antibody response to other serotypes. Priming with JEV vaccines did not impact on dengue virus-specific neutralizing antibody response to a dengue TDNA vaccine candidate in mice.

  20. Findings at brain MRI in children with dengue fever and neurological symptoms.

    PubMed

    Rastogi, Ruchi; Garg, Bhavya

    2016-01-01

    Dengue is a flavivirus of the genus arbovirus with four serotypes, from DEN 1 to DEN 4. There has been an increase in incidence of dengue infection in children in the tropics and subtropics. Dengue has a variable clinical presentation, with many patients being asymptomatic. Its clinical manifestations in children vary from fever and arthralgia to life-threatening dengue hemorrhagic fever and dengue shock syndrome. We describe MRI findings in children with neurological involvement including dengue encephalopathy, acute hypoxic injury and dengue encephalitis. Dengue encephalopathy is usually secondary to multisystem derangement such as shock, hepatitis, coagulopathy and concurrent bacterial infection and is relatively common. Dengue encephalitis from direct neuronal invasion is rare. Nonspecific changes are seen on brain MRI in dengue infection. Clinical and laboratory findings as well as outcome do not necessarily correspond with brain MRI findings.

  1. Dengue Knowledge and Preventive Practices in Iquitos, Peru

    PubMed Central

    Paz-Soldán, Valerie A.; Morrison, Amy C.; Cordova Lopez, Jhonny J.; Lenhart, Audrey; Scott, Thomas W.; Elder, John P.; Sihuincha, Moises; Kochel, Tadeusz J.; Halsey, Eric S.; Astete, Helvio; McCall, Philip J.

    2015-01-01

    As part of a cluster-randomized trial to evaluate insecticide-treated curtains for dengue prevention in Iquitos, Peru, we surveyed 1,333 study participants to examine knowledge and reported practices associated with dengue and its prevention. Entomological data from 1,133 of these households were linked to the survey. Most participants knew that dengue was transmitted by mosquito bite (85.6%), but only few (18.6%) knew that dengue vectors bite during daytime. Most commonly recognized dengue symptoms were fever (86.6%), headache (76.4%), and muscle/joint pain (67.9%). Most commonly reported correct practices for mosquito control were cleaning homes (61.6%), using insecticide sprays (23%), and avoiding having standing water at home (12.3%). Higher education was associated with higher knowledge about dengue, including transmission and vector control. Higher socioeconomic status was associated with increased reported use of preventive practices requiring money expenditure. We were less likely to find Aedes aegypti eggs, larvae, or pupae in households that had < 5-year-old children at home. Although dengue has been transmitted in Iquitos since the 1990s and the Regional Health Authority routinely fumigates households, treats domestic water containers with larvicide, and issues health education messages through mass media, knowledge of dengue transmission and household practices for prevention could be improved. PMID:26503276

  2. Assessing weather effects on dengue disease in Malaysia.

    PubMed

    Cheong, Yoon Ling; Burkart, Katrin; Leitão, Pedro J; Lakes, Tobia

    2013-11-26

    The number of dengue cases has been increasing on a global level in recent years, and particularly so in Malaysia, yet little is known about the effects of weather for identifying the short-term risk of dengue for the population. The aim of this paper is to estimate the weather effects on dengue disease accounting for non-linear temporal effects in Selangor, Kuala Lumpur and Putrajaya, Malaysia, from 2008 to 2010. We selected the weather parameters with a Poisson generalized additive model, and then assessed the effects of minimum temperature, bi-weekly accumulated rainfall and wind speed on dengue cases using a distributed non-linear lag model while adjusting for trend, day-of-week and week of the year. We found that the relative risk of dengue cases is positively associated with increased minimum temperature at a cumulative percentage change of 11.92% (95% CI: 4.41-32.19), from 25.4 °C to 26.5 °C, with the highest effect delayed by 51 days. Increasing bi-weekly accumulated rainfall had a positively strong effect on dengue cases at a cumulative percentage change of 21.45% (95% CI: 8.96, 51.37), from 215 mm to 302 mm, with the highest effect delayed by 26-28 days. The wind speed is negatively associated with dengue cases. The estimated lagged effects can be adapted in the dengue early warning system to assist in vector control and prevention plan.

  3. Therapeutic antibodies as a treatment option for dengue fever.

    PubMed

    Chan, Kuan Rong; Ong, Eugenia Z; Ooi, Eng Eong

    2013-11-01

    Dengue fever is the most prevalent mosquito-borne viral disease globally with about 100 million cases of acute dengue annually. Severe dengue infection can result in a life-threatening illness. In the absence of either a licensed vaccine or antiviral drug against dengue, therapeutic antibodies that neutralize dengue virus (DENV) may serve as an effective medical countermeasure against severe dengue. However, therapeutic antibodies would need to effectively neutralize all four DENV serotypes. It must not induce antibody-dependent enhancement of DENV infection in monocytes/macrophages through Fc gamma receptor (FcγR)-mediated phagocytosis, which is hypothesized to increase the risk of severe dengue. Here, we review the strategies and technologies that can be adopted to develop antibodies for therapeutic applications. We also discuss the mechanism of antibody neutralization in the cells targeted by DENV that express Fc gamma receptor. These studies have provided significant insight toward the use of therapeutic antibodies as a potentially promising bulwark against dengue.

  4. Community beliefs and practices about dengue in Puerto Rico

    USDA-ARS?s Scientific Manuscript database

    In spite of long-term endemicity and repeated government and private efforts, effective, sustained community participation for dengue prevention is still a challenge in Puerto Rico. This study explored differences found in interviews conducted in 2001 in attitudes toward dengue and its prevention by...

  5. Perinatal transmission of dengue: a report of 7 cases.

    PubMed

    Ribeiro, Christiane Fernandes; Lopes, Vânia Glória Silami; Brasil, Patrícia; Coelho, Janice; Muniz, Adriana Gouveia; Nogueira, Rita Maria Ribeiro

    2013-11-01

    Perinatal transmission of dengue virus was confirmed by the evidence of virus in fetal tissue, newborn serum, and placenta of pregnant women. Abortion, several different clinical findings, and placental inflammatory findings were documented. No association was seen between severity of maternal dengue and disease of the newborn.

  6. Dengue fever presenting with acute cerebellitis: a case report.

    PubMed

    Withana, Milinda; Rodrigo, Chaturaka; Chang, Thashi; Karunanayake, Panduka; Rajapakse, Senaka

    2014-03-05

    The incidence of dengue fever is on the rise in tropical countries. In Sri Lanka, nearly 45,000 patients were reported in 2012. With the increasing numbers, rare manifestations of dengue are occasionally encountered. We report a patient who presented with bilateral cerebellar signs as the presenting feature of dengue. A 45-year-old previously healthy female from the suburbs of Colombo, Sri Lanka presented with an acute febrile illness associated with unsteadiness of gait. Clinical examination revealed a scanning dysarthria and marked horizontal nystagmus with bilateral dysmetria, dysdiadokokinesia and incordination more prominent on the right. Her gait was wide-based and ataxic with a tendency to fall to the right more than to the left. Dengue nonstructural protein antigen 1 test and IgM antibody testing both became positive indicating acute dengue infection. She recovered from the febrile episode within 9 days since the onset of fever but cerebellar symptoms outlasted the fever by one week. The magnetic resonance imaging of brain was normal and cerebellar signs resolved spontaneously by day 17 of the illness. Cerebellar syndrome in association with dengue fever has been reported in only four instances and our patient is the first reported case of dengue fever presenting with cerebellitis as the first manifestation of disease. This case report is intended to highlight the occurrence of acute cerebellitis as a presenting syndrome of the expanding list of unusual neurological manifestations of dengue infection.

  7. Guillain-Barre syndrome following dengue fever and literature review.

    PubMed

    Ralapanawa, Dissanayake Mudiyanselage Priyantha Udaya Kumara; Kularatne, Senanayake Abeysinghe Mudiyanselage; Jayalath, Widana Arachilage Thilak Ananda

    2015-11-27

    Dengue is an arboviral infection that classically presents with fever, joint pain, headaches, skin flush and morbilliform rashes. The incidence of neurological symptoms and complications in dengue varies from 1 to 25% that include encephalopathy, Guillain-Barre syndrome (GBS), acute motor weakness, seizures, neuritis, hypokalaemic paralysis, pyramidal tract signs, and a few more. Dengue fever as an antecedent infection in GBS is uncommon. A 34-years-old Sri Lankan Sinhalese male presented with fever, headache and myalgia of 3 days and developed leucopenia and thrombocytopenia without evidence of haemoconcentration. The diagnosis of dengue fever was confirmed as he had positive dengue NS1 antigen test on the third day of fever. He made full recovery and was discharged after 4 days of hospital stay. Six days later, he presented with history of acute flaccid weakness of both lower limbs and upper limbs which was of progressive ascending nature. The electromyography had evidence of demyelinating neuropathy and cerebrospinal fluid showed albuminocytological dissociation. Subsequently, IgM for dengue virus was positive. Dengue is endemic in Sri Lanka. Post dengue Guillain-Barre syndrome is a potential neurological complications of this infection.

  8. Projections of increased and decreased dengue incidence under climate change.

    PubMed

    Williams, C R; Mincham, G; Faddy, H; Viennet, E; Ritchie, S A; Harley, D

    2016-10-01

    Dengue is the world's most prevalent mosquito-borne disease, with more than 200 million people each year becoming infected. We used a mechanistic virus transmission model to determine whether climate warming would change dengue transmission in Australia. Using two climate models each with two carbon emission scenarios, we calculated future dengue epidemic potential for the period 2046-2064. Using the ECHAM5 model, decreased dengue transmission was predicted under the A2 carbon emission scenario, whereas some increases are likely under the B1 scenario. Dengue epidemic potential may decrease under climate warming due to mosquito breeding sites becoming drier and mosquito survivorship declining. These results contradict most previous studies that use correlative models to show increased dengue transmission under climate warming. Dengue epidemiology is determined by a complex interplay between climatic, human host, and pathogen factors. It is therefore naive to assume a simple relationship between climate and incidence, and incorrect to state that climate warming will uniformly increase dengue transmission, although in general the health impacts of climate change will be negative.

  9. Dengue in the United States of America: A Worsening Scenario?

    PubMed Central

    Rios, Maria

    2013-01-01

    Dengue is a febrile illness caused by any of the four dengue virus types (DENV-1 to -4, genus Flavivirus, family Flaviviridae) mainly transmitted by the mosquito Aedes aegypti. DENV can be transmitted by blood transfusion. Dengue has been historically present in the continental United States (US), in the state of Hawaii, and in the US insular territories in the Caribbean and the Pacific. During the second half of the 20th century, most of the cases reported in the US were imported cases brought to the country by travelers. Since 2009, cases of autochthonous dengue have been recognized in the state of Florida after 75 years of absence, followed by intensification of transmission in endemic places including the US territories of US Virgin Islands and Puerto Rico, which experienced a large dengue epidemic in 2010. The widespread distribution of dengue mosquito vectors, deficient mosquito control measures and increased frequency of DENV-infected visitors to the US coming from dengue-endemic locations or places experiencing epidemics appear to be jointly responsible for the emergence and reemergence of dengue in the US and its territories. PMID:23865061

  10. Investigation of spatiotemporal relationship between dengue fever and drought

    NASA Astrophysics Data System (ADS)

    Lee, Chieh-Han; Yu, Hwa-Lung

    2016-04-01

    Dengue Fever is a vector-borne disease that is transmitted between human and mosquitos in tropical and sub-tropical regions. Previous studies have found significant relationship between the epidemic of dengue cases and climate variables, especially temperature and precipitation. Besides, the natural phenomena (e.g., drought) are considered that significantly drop the number of dengue cases by killing vector's breeding environment. However, in Kaohsiung City, Taiwan, there are evidences that the temporal pattern of dengue is correlated to drought events. Kaohsiung City experienced two main dengue outbreaks in 2002 and 2014 that both years were confirmed with serious drought. Especially in 2014, Kaohsiung City was suffered from extremely dengue outbreak in 2014 that reported the highest number of dengue cases in the history. Otherwise, another nearby city, Tainan City, had reported the biggest outbreak in 2015. This study constructs the spatiotemporal model of dengue incidences and index of drought events (Standardized Precipitation Index, SPI) based on the distributed lag nonlinear model (DLNM). Other meteorological measures are also included in the analysis.

  11. The GOOD-BYE TO DENGUE GAME: Debriefing Study

    ERIC Educational Resources Information Center

    Lennon, Jeffrey L.; Coombs, David W.

    2005-01-01

    This study examined the use of postgame debriefing of a health educational board game activity on dengue fever in a Filipino student population. The debriefing used a series of specific open-ended questions, exploring students' feelings about the game and game-related questionnaires, students' perceptions of important information about dengue from…

  12. Dengue data and surveillance in Tanzania: a systematic literature review.

    PubMed

    Ward, Tara; Samuel, Moody; Maoz, Dorit; Runge-Ranzinger, Silvia; Boyce, Ross; Toledo, Joao; Velayudhan, Raman; Horstick, Olaf

    2017-08-01

    Although there is evidence that dengue virus is circulating in Tanzania, the country lacks a dengue surveillance system. Consequently, the true estimate of dengue seroprevalence, as well as the incidence in the population, the frequency and magnitude of outbreaks is unknown. This study therefore sought to systematically review available dengue data from Tanzania. The systematic review was conducted and reported using the PRISMA tool. Five databases (PubMed, Embase, Web of Science, WHOLIS and Google Scholar) were searched for articles using various keywords on the illness, data and geographical location. Identified articles were assessed for inclusion based on predefined eligibility criteria. Data were extracted from included articles, analysed and reported. Based on the 10 seroprevalence studies in defined populations with estimates of acute confirmed infections that were included in the review, the estimated seroprevalence of past dengue infection in Tanzania ranged from 50.6% in a health facility-based study to 11% in a population-based study. Acute confirmed infections of dengue were estimated to be as high as 38.2% of suspected cases. Only one study reported on an outbreak. It is evident that dengue needs to become part of regular disease surveillance in Tanzania. Control measures need to be instituted with a focus on building human resource capacity and integrating dengue control measures in ongoing health programmes, for both preventive and curative interventions. Systematic reviews are valuable in assessing health issues when surveillance data are not available. © 2017 John Wiley & Sons Ltd.

  13. The GOOD-BYE TO DENGUE GAME: Debriefing Study

    ERIC Educational Resources Information Center

    Lennon, Jeffrey L.; Coombs, David W.

    2005-01-01

    This study examined the use of postgame debriefing of a health educational board game activity on dengue fever in a Filipino student population. The debriefing used a series of specific open-ended questions, exploring students' feelings about the game and game-related questionnaires, students' perceptions of important information about dengue from…

  14. Dengue virus type 3, South Pacific Islands, 2013.

    PubMed

    Cao-Lormeau, Van-Mai; Roche, Claudine; Musso, Didier; Mallet, Henri-Pierre; Dalipanda, Tenneth; Dofai, Alfred; Nogareda, Francisco; Nilles, Eric J; Aaskov, John

    2014-06-01

    After an 18-year absence, dengue virus serotype 3 reemerged in the South Pacific Islands in 2013. Outbreaks in western (Solomon Islands) and eastern (French Polynesia) regions were caused by different genotypes. This finding suggested that immunity against dengue virus serotype, rather than virus genotype, was the principal determinant of reemergence.

  15. Hanta virus infection during dengue virus infection outbreak in Indonesia.

    PubMed

    Suharti, Catharina; van Gorp, Eric C M; Dolmans, Wil M V; Groen, Jan; Hadisaputro, Suharyo; Djokomoeljanto, Robert J; D M E, Osterhaus Ab; van der Meer, Jos W M

    2009-04-01

    To investigate which recent infection could have caused the present dengue-like symptoms, in adult patients clinically fulfilling the WHO criteria for dengue, in which serologically were not confirmed for dengue virus infections. Prospective study. During an outbreak of dengue (between May 1995 and May 1996) 118 consecutive adults (>13 years) suspected by the WHO 1997 case definition of DF or DHF were investigated. Patients were examined for history of illness, physical and laboratory findings consisting of full blood counts, prothrombin time (PT), activated partial thromboplastin time (aPTT), liver function (bilirubin, ASAT, ALAT), renal function (creatinine), and serological assays included dengue, hantavirus, chikungunya, R. typhi, R. tsutsugamuchi, rubella virus, influenza A virus, and leptospira. In 58 of the total 118 patients, recent dengue virus infection was serologically confirmed. In 20 of the remaining 60 patients, we found serological evidence of another recent infection: hantavirus (5), chikungunya virus (2), R. typhi (5), R. tsutsugamuchi (2), rubella virus (3), influenza A virus (1), and leptospira (2). No evidence for recent infection with any of the mentioned agents was detected in the remaining 40 specimens. We conclude that based on clinical characteristics alone, it is not easy to diagnose dengue. Specific laboratory tests to differentiate dengue from other febrile illnesses are needed. Among these, in Indonesia hantavirus infection should be considered as well.

  16. Dengue Knowledge and Preventive Practices in Iquitos, Peru.

    PubMed

    Paz-Soldán, Valerie A; Morrison, Amy C; Cordova Lopez, Jhonny J; Lenhart, Audrey; Scott, Thomas W; Elder, John P; Sihuincha, Moises; Kochel, Tadeusz J; Halsey, Eric S; Astete, Helvio; McCall, Philip J

    2015-12-01

    As part of a cluster-randomized trial to evaluate insecticide-treated curtains for dengue prevention in Iquitos, Peru, we surveyed 1,333 study participants to examine knowledge and reported practices associated with dengue and its prevention. Entomological data from 1,133 of these households were linked to the survey. Most participants knew that dengue was transmitted by mosquito bite (85.6%), but only few (18.6%) knew that dengue vectors bite during daytime. Most commonly recognized dengue symptoms were fever (86.6%), headache (76.4%), and muscle/joint pain (67.9%). Most commonly reported correct practices for mosquito control were cleaning homes (61.6%), using insecticide sprays (23%), and avoiding having standing water at home (12.3%). Higher education was associated with higher knowledge about dengue, including transmission and vector control. Higher socioeconomic status was associated with increased reported use of preventive practices requiring money expenditure. We were less likely to find Aedes aegypti eggs, larvae, or pupae in households that had < 5-year-old children at home. Although dengue has been transmitted in Iquitos since the 1990s and the Regional Health Authority routinely fumigates households, treats domestic water containers with larvicide, and issues health education messages through mass media, knowledge of dengue transmission and household practices for prevention could be improved. © The American Society of Tropical Medicine and Hygiene.

  17. Dengue Outbreak in Hadramout, Yemen, 2010: An Epidemiological Perspective

    PubMed Central

    Ghouth, Abdulla Salim Bin; Amarasinghe, Ananda; Letson, G. William

    2012-01-01

    We analyzed surveillance data of a dengue outbreak (2010) reported to the Hadramout Health Office (Yemen) and retrospectively analyzed dengue-related epidemiological and entomological events reported in Hadramout from 2005 to 2009. A total of 630 immunoglobulin M (IgM) -confirmed dengue cases of 982 febrile cases was reported during the period from February to June of 2010; 12 cases died, giving case fatality a rate of 1.9%. Among febrile cases, the highest proportion of dengue cases (37.3%) was reported in the 15- to 24-year-old age group. The overall attack rate was 0.89/1,000. The average number of cases reported by month over the preceding 5-year period compared with the 2010 data is consistent with endemicity of dengue in the region and supports epidemic designation for the dengue activity in 2010. Recognition of endemic dengue transmission and potential for substantial dengue epidemics highlight the need for consistent laboratory-based surveillance that can support prevention and control activities accordingly. PMID:22665621

  18. Isolation of Ancestral Sylvatic Dengue Virus Type 1, Malaysia

    PubMed Central

    Teoh, Boon-Teong; Sam, Sing-Sin; Abd-Jamil, Juraina

    2010-01-01

    Ancestral sylvatic dengue virus type 1, which was isolated from a monkey in 1972, was isolated from a patient with dengue fever in Malaysia. The virus is neutralized by serum of patients with endemic DENV-1 infection. Rare isolation of this virus suggests a limited spillover infection from an otherwise restricted sylvatic cycle. PMID:21029545

  19. [Dengue with unusual clinical features in an infant. Case report].

    PubMed

    Méndez-Domínguez, Nina; Achach-Medina, Kikey; Morales-Gual, Yareni María; Gómez-Carro, Salvador

    2016-07-01

    The state of Yucatan, in Mexico, is an endemic area for dengue. During 2015, there was an unpredicted increase in the number of expected cases of dengue fever. To describe and analyse the clinical presentation, progress, and management of a case of dengue infection with non-specific clinical manifestations in an infant which resulted in a dengue shock syndrome. One month old infant admitted to hospital with a generalised rash and a history of being bitten by an insect. He was diagnosed with anaphylaxis based on clinical manifestations and anamnesis. While in hospital, he developed hypotension, tachycardia, anaemia, and respiratory distress. He was transferred to the intensive care unit, but died on the fifth day. He tested positive to dengue virus in the PCR test and for IgG antibodies using Elisa. The basic cause of death was dengue shock syndrome. Dengue fever in young infant infections may be afebrile, so it is important to suspect them appropriately in the presence of a generalised rash, tachycardia, and hypotension, in order to avoid the deadly consequences of dengue shock. Copyright © 2016 Sociedad Chilena de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

  20. Potential biomarkers for the clinical prognosis of severe dengue.

    PubMed

    Silva, Mayara Marques Carneiro da; Gil, Laura Helena Vega Gonzales; Marques, Ernesto Torres de Azevedo; Calzavara-Silva, Carlos Eduardo

    2013-09-01

    Currently, several assays can confirm acute dengue infection at the point-of-care. However, none of these assays can predict the severity of the disease symptoms. A prognosis test that predicts the likelihood of a dengue patient to develop a severe form of the disease could permit more efficient patient triage and treatment. We hypothesise that mRNA expression of apoptosis and innate immune response-related genes will be differentially regulated during the early stages of dengue and might predict the clinical outcome. Aiming to identify biomarkers for dengue prognosis, we extracted mRNA from the peripheral blood mononuclear cells of mild and severe dengue patients during the febrile stage of the disease to measure the expression levels of selected genes by quantitative polymerase chain reaction. The selected candidate biomarkers were previously identified by our group as differentially expressed in microarray studies. We verified that the mRNA coding for CFD, MAGED1, PSMB9, PRDX4 and FCGR3B were differentially expressed between patients who developed clinical symptoms associated with the mild type of dengue and patients who showed clinical symptoms associated with severe dengue. We suggest that this gene expression panel could putatively serve as biomarkers for the clinical prognosis of dengue haemorrhagic fever.

  1. Seroepidemiology of Asymptomatic Dengue Virus Infection in Jeddah, Saudi Arabia

    PubMed Central

    Jamjoom, Ghazi A.; Azhar, Esam I.; Kao, Moujahid A.; Radadi, Raja M.

    2016-01-01

    BACKGROUND Although virologically confirmed dengue fever has been recognized in Jeddah, Saudi Arabia, since 1994, causing yearly outbreaks, no proper seroepidemiologic studies on dengue virus have been conducted in this region. Such studies can define the extent of infection by this virus and estimate the proportion that may result in disease. The aim of this study was to measure the seroprevalence of past dengue virus infection in healthy Saudi nationals from different areas in the city of Jeddah and to investigate demographic and environmental factors that may increase exposure to infection. METHODS Sera were collected from 1984 Saudi subjects attending primary health care centers in six districts of Jeddah. These included general patients of various ages seeking routine vaccinations, antenatal care or treatment of different illnesses excluding fever or suspected dengue. A number of blood donors were also tested. Serum samples were tested by enzyme immunoassay (EIA) for IgG antibodies to dengue viruses 1, 2, 3, 4. A questionnaire was completed for each patient recording various anthropometric data and factors that may indicate possible risk of exposure to mosquito bites and dengue infection. Patients with missing data and those who reported a history of dengue fever were excluded from analysis, resulting in a sample of 1939 patients to be analyzed. RESULTS The overall prevalence of dengue virus infection as measured by anti-dengue IgG antibodies from asymptomatic residents in Jeddah was 47.8% (927/1939) and 37% (68/184) in blood donors. Infection mostly did not result in recognizable disease, as only 19 of 1956 subjects with complete information (0.1%) reported having dengue fever in the past. Anti dengue seropositivity increased with age and was higher in males than females and in residents of communal housing and multistory buildings than in villas. One of the six districts showed significant increase in exposure rate as compared to the others. Availability of

  2. [Dengue fever cases in Czech workers returning from the Maldives].

    PubMed

    Trojánek, Milan; Tomíčková, Dora; Roháčová, Hana; Kosina, Pavel; Gebouský, Jan; Dvořák, Jan; Chmelik, Vaclav; Batistová, Květoslava; Husa, Petr; Maixner, Jan; Sojková, Naděžda; Zelená, Hana; Marešová, Vilma; Stejskal, František

    2013-09-01

    The objective of this study is to present epidemiological characteristics and clinical symptoms of dengue fever cases in Czech workers who acquired the infection while working on the island of Fushivelavaru, Maldives. Furthermore, the study compares the sensitivity of novel direct detection assays, i.e. Real-Time Polymerase Chain Reaction (RT-PCR) and detection of Dengue NS1 antigen. The retrospective study evaluated the clinical course of dengue fever cases in Czech workers returning from a job in the Maldives who were diagnosed with dengue virus infection from September 1 to October 31, 2012. The laboratory diagnosis of dengue fever was based on the serological detection of IgM and IgG antibodies, detection of dengue NS1 antigen by enzyme-linked immunosobent assay (ELISA), and detection of dengue virus DNA by RT-PCR. The infection with dengue virus was confirmed in 18 males with a median age of 40 years (IQR 36-47) who returned from a job in the Maldives. Only one patient required admission to the hospital while the others were treated on an outpatient basis. The most frequently observed symptoms were fever (18), headache (9), muscle and joint pain (8 and 7, respectively), and rash (9). Typical laboratory findings were leukocytopenia and thrombocytopenia, a low CRP level, and elevated aminotransferase activity. The clinical course was uncomplicated in all patients. The dengue NS1 antigen detection (positive in all 10 patients with acute dengue fever) showed significantly higher sensitivity than the detection of viral RNA using RT-PCR (positive in 4 patients), p = 0.011. Although the vast majority of dengue fever cases are diagnosed among travellers returning from the tropics, the presented study points out the risks posed by dengue fever to long-term workers in endemic areas. The infection in the serologically naïve hosts is usually uncomplicated; however, infected persons are at significant risk of developing a severe complicated clinical course if challenged

  3. Cavity Forming Pneumonia Due to Staphylococcus aureus Following Dengue Fever.

    PubMed

    Miyata, Nobuyuki; Yoshimura, Yukihiro; Tachikawa, Natsuo; Amano, Yuichiro; Sakamoto, Yohei; Kosuge, Youko

    2015-11-01

    While visiting Malaysia, a 22-year-old previously healthy Japanese man developed myalgia, headache, and fever, leading to a diagnosis of classical dengue fever. After improvement and returning to Japan after a five day hospitalization, he developed productive cough several days after defervescing from dengue. Computed tomography (CT) thorax scan showed multiple lung cavities. A sputum smear revealed leukocytes with phagocytized gram-positive cocci in clusters, and grew an isolate Staphylococcus aureus sensitive to semi-synthetic penicillin; he was treated successfully with ceftriaxone and cephalexin. This second reported case of pneumonia due to S. aureus occurring after dengue fever, was associated both with nosocomial exposure and might have been associated with dengue-associated immunosuppression. Clinicians should pay systematic attention to bacterial pneumonia following dengue fever to establish whether such a connection is causally associated. © The American Society of Tropical Medicine and Hygiene.

  4. Unilateral massive hemothorax in Dengue hemorrhagic fever: a unique presentation.

    PubMed

    Karanth, Suman S; Gupta, Anurag; Prabhu, Mukhyaprana

    2012-09-01

    Dengue hemorrhagic fever is a more serious form of disease characterised by plasma leakage syndrome, thrombocytopenia and disseminated intravascular coagulation. We present a 51 year old male who presented with fever, petechiae and acute onset of breathlessness. Emergency chest rhoentogram showed a massive right sided pleural effusion. On insertion of intercostal drain, there was a sudden gush of blood tinged fluid suggestive of hemothorax. There was no history of trauma or bleeding tendencies. Laboratory investigations revealed a raised hematocrit and severe thrombocytopenia. Dengue IgM was surprisingly positive. After aggressive supportive management the patient gradually improved and was discharged. While bilateral pleural effusion is a known occurrence in dengue hemorrhagic fever, massive hemothorax is unheard of. We report the first case in literature of dengue hemorrhagic fever presenting as unilateral massive hemothorax. A suspicion of dengue must also be borne in mind in cases of non-traumatic hemothorax especially in endemic areas.

  5. Towards antiviral therapies for treating dengue virus infections.

    PubMed

    Kaptein, Suzanne Jf; Neyts, Johan

    2016-10-01

    Dengue virus is an emerging human pathogen that poses a huge public health burden by infecting annually about 390 million individuals of which a quarter report with clinical manifestations. Although progress has been made in understanding dengue pathogenesis, a licensed vaccine or antiviral therapy against this virus is still lacking. Treatment of patients is confined to symptomatic alleviation and supportive care. The development of dengue therapeutics thus remains of utmost importance. This review focuses on the few molecules that were evaluated in dengue virus-infected patients: balapiravir, chloroquine, lovastatin, prednisolone and celgosivir. The lessons learned from these clinical trials can be very helpful for the design of future trials for the next generation of dengue virus inhibitors. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. The History of Dengue Outbreaks in the Americas

    PubMed Central

    Brathwaite Dick, Olivia; San Martín, José L.; Montoya, Romeo H.; del Diego, Jorge; Zambrano, Betzana; Dayan, Gustavo H.

    2012-01-01

    Dengue is a viral disease usually transmitted by Aedes aegypti mosquitoes. Dengue outbreaks in the Americas reported in medical literature and to the Pan American Health Organization are described. The outbreak history from 1600 to 2010 was categorized into four phases: Introduction of dengue in the Americas (1600–1946); Continental plan for the eradication of the Ae. aegypti (1947–1970) marked by a successful eradication of the mosquito in 18 continental countries by 1962; Ae. aegypti reinfestation (1971–1999) caused by the failure of the mosquito eradication program; Increased dispersion of Ae. aegypti and dengue virus circulation (2000–2010) characterized by a marked increase in the number of outbreaks. During 2010 > 1.7 million dengue cases were reported, with 50,235 severe cases and 1,185 deaths. A dramatic increase in the number of outbreaks has been reported in recent years. Urgent global action is needed to avoid further disease spread. PMID:23042846

  7. Geographical structure of dengue transmission and its determinants in Thailand.

    PubMed

    Nagao, Y; Svasti, P; Tawatsin, A; Thavara, U

    2008-06-01

    Expansion of dengue has been attributed to urbanization. To test this concept, we examined dengue transmission intensities in Thailand. We used the inverse of mean age of dengue haemorrhagic fever (DHF) cases as a surrogate of dengue transmission intensity (or force of infection). The transmission intensity in Bangkok decreased rapidly since the mid-1990s, to levels that are currently lower than in other regions. Regression analysis revealed that transmission intensity is highest in the Northeastern rural region, mainly due to scarcity of private water wells. Private wells reduce the need for household water containers, the major breeding sites for vectors. Cumulatively, these results show that urbanization is not necessarily associated with intense dengue transmission in Thailand. Paradoxically, the DHF incidence in Bangkok has surpassed other regions despite declines in transmission intensity. This finding implies the existence of endemic stability (i.e. low incidence of a clinical illness in spite of high transmission intensity).

  8. Multiple dengue virus types harbored by individual mosquitoes.

    PubMed

    Angel, Bennet; Angel, Annette; Joshi, Vinod

    2015-10-01

    The existing knowledge on pathogenesis and aetiology of DHF establishes that Dengue Hemorrhagic Fever (DHF) and Dengue Shock Syndrome (DSS) are caused by two subsequent infections of two different serotypes of dengue affecting a common human population with a time gap. Present studies have been undertaken on 212 laboratory reared infected individual mosquitoes from larvae collected from 31 dengue endemic towns of Rajasthan, India. Type specific DEN viruses were detected from individual mosquitoes employing RT-PCR. In 78.7% of 212 infected individual mosquitoes studied, vertically transmitted multiple DENV types were observed. We report for the first time that single mosquitoes contain multiple dengue virus types. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Seven native cases of dengue in Abidjan, Ivory Coast.

    PubMed

    Aoussi, E B F; Ehui, E; Kassi, N A; Kouakou, G; Nouhou, Y; Adjogoua, E V; Eholié, S; Bissagnéné, E

    2014-09-01

    We had for aim to describe the epidemiological, clinical, biological, and outcome features of dengue fever in Abidjan, in 2010. We retrospectively studied the files of patients hospitalized for dengue fever in 2010, in Abidjan. The diagnosis was made on clinical symptoms and positive dengue PCR and/or IgM. Seven patients were included (5 men, 2 women, median age of 51years [31-65years]). They presented with a febrile pain syndrome (n=7), jaundice (n=3), rash (n=2), and hematemesis complicated by thrombocytopenia (n=6) and leukopenia (n=5). Three patients had a positive IgM serology and 4 had a positive dengue PCR for DENV-3. The outcome was favorable for 6 patients, and 1 patient died of severe hemorrhage. The authors advocate the implementation of epidemiological surveillance of dengue and vector control in the Ivory Coast. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  10. Clinical profile of dengue hemorrhagic fever cases in Mexico.

    PubMed

    Navarrete-Espinosa, Joel; Gómez-Dantés, Héctor; Celis-Quintal, Juan Germán; Vázquez-Martínez, José Luis

    2005-01-01

    Dengue hemorrhagic fever is a public health problem in Mexico since 1994. With four serotypes circulating the risk of epidemic dengue hemorrhagic fever is increasing. We describe the clinical features of confirmed cases in the social security health system (IMSS) from 1995 to 2003. Clinical picture and epidemiological features were compared and a multivariate model was fitted to evaluate associations. Cases were divided into two groups: 438 patients with dengue fever, including 109 cases with hemorrhagic manifestations without thrombocytopenia, and 977 cases with dengue hemorrhagic fever, including 79 deaths. The main risk factors associated with mortality were hematemesis (RR 2.6; CI 95% 1.4-4.6) and melena (RR 2.2; Cl 95% 1.2-3.7). Our results characterize the clinical profile of dengue hemorrhagic fever cases in Mexico and identify prognostic factors to alert clinician for the prevention of a fatal evolution.

  11. The history of dengue outbreaks in the Americas.

    PubMed

    Brathwaite Dick, Olivia; San Martín, José L; Montoya, Romeo H; del Diego, Jorge; Zambrano, Betzana; Dayan, Gustavo H

    2012-10-01

    Dengue is a viral disease usually transmitted by Aedes aegypti mosquitoes. Dengue outbreaks in the Americas reported in medical literature and to the Pan American Health Organization are described. The outbreak history from 1600 to 2010 was categorized into four phases: Introduction of dengue in the Americas (1600-1946); Continental plan for the eradication of the Ae. aegypti (1947-1970) marked by a successful eradication of the mosquito in 18 continental countries by 1962; Ae. aegypti reinfestation (1971-1999) caused by the failure of the mosquito eradication program; Increased dispersion of Ae. aegypti and dengue virus circulation (2000-2010) characterized by a marked increase in the number of outbreaks. During 2010 > 1.7 million dengue cases were reported, with 50,235 severe cases and 1,185 deaths. A dramatic increase in the number of outbreaks has been reported in recent years. Urgent global action is needed to avoid further disease spread.

  12. Dengue Infection Increases the Locomotor Activity of Aedes aegypti Females

    PubMed Central

    Luz, Paula M.; Castro, Márcia G.; Lourenço-de-Oliveira, Ricardo; Sorgine, Marcos H. F.; Peixoto, Alexandre A.

    2011-01-01

    Background Aedes aegypti is the main vector of the virus causing Dengue fever, a disease that has increased dramatically in importance in recent decades, affecting many tropical and sub-tropical areas of the globe. It is known that viruses and other parasites can potentially alter vector behavior. We investigated whether infection with Dengue virus modifies the behavior of Aedes aegypti females with respect to their activity level. Methods/Principal Findings We carried out intrathoracic Dengue 2 virus (DENV-2) infections in Aedes aegypti females and recorded their locomotor activity behavior. We observed an increase of up to ∼50% in the activity of infected mosquitoes compared to the uninfected controls. Conclusions Dengue infection alters mosquito locomotor activity behavior. We speculate that the higher levels of activity observed in infected Aedes aegypti females might involve the circadian clock. Further studies are needed to assess whether this behavioral change could have implications for the dynamics of Dengue virus transmission. PMID:21408119

  13. Clinical and laboratory factors associated with mortality in dengue.

    PubMed

    Saroch, Atul; Arya, Vivek; Sinha, Nitin; Taneja, R S; Sahai, Pooja; Mahajan, R K

    2017-04-01

    Dengue is endemic in more than 100 countries, giving rise to an increased number of deaths in the last five years in the South-East Asian region. We report our findings from a retrospective study of adults admitted with confirmed dengue at our institution. We studied the clinical and laboratory parameters associated with mortality in these patients. Of the 172 hospitalised patients studied, 156 (90.69 %) recovered while 16 (9.3%) died. Univariate analysis showed altered sensorium on presentation, lower haemoglobin and haematocrit levels, higher serum creatinine, higher serum transaminase and lower serum albumin levels to be significantly associated with mortality in dengue. Further, using stepwise multivariate logistic regression, altered sensorium ( P = 0.006) and hypoalbuminemia ( P = 0.013) were identified as independent predictors of mortality in dengue. Identification of these parameters early in the course of disease should prompt intensification of treatment in dengue cases.

  14. Characterization of dengue virus serotype 4 infection in Jakarta, Indonesia.

    PubMed

    Dewi, Beti Ernawati; Naiggolan, Leonard; Putri, Dwi Hilda; Rachmayanti, Novia; Albar, Sarah; Indriastuti, Nadia Tita; Sjamsuridzal, Wellyzar; Sudiro, T Mirawati

    2014-01-01

    Dengue hemorrhagic fever has become a worldwide health issue. Heterologous infection by different serotypes may lead to severe forms of dengue infection and even death. In a cohort study in Jakarta from 2009 to 2010 with inclusion criteria of adults with fever of less than 48 hours, 72% were confirmed dengue infection from a total of suspected 190 dengue patients. Using RT-PCR, 16 patients were infected with DENV-4 with or without co-infection with other serotype(s). Dengue fever (DF) patients (73%) were infected with DENV-4 alone, while mixed infections were present in more severe clinical manifestations of DHF grade I and II. The nucleotide sequences of envelope (E) protein gene of 3 isolates of DENV-4 showed that they belonged to genotype II. There were 50 nucleotide substitutions, but only 3 amino acid changes were found at positions 130, 233 and 455, present in E protein isolated from DHF grade II patient.

  15. Performance of the Tourniquet Test for Diagnosing Dengue in Peru

    PubMed Central

    Halsey, Eric S.; Vilcarromero, Stalin; Forshey, Brett M.; Rocha, Claudio; Bazan, Isabel; Stoddard, Steven T.; Kochel, Tadeusz J.; Casapia, Martin; Scott, Thomas W.; Morrison, Amy C.

    2013-01-01

    The tourniquet test (TT) is a physical examination maneuver often performed on patients suspected of having dengue. It has been incorporated into dengue diagnostic guidelines and is used in clinical studies. However, little is known about TT performance characteristics in different patient types or epidemiologic conditions. In the dengue-endemic city of Iquitos, Peru, we performed TTs and dengue laboratory assays on 13,548 persons with febrile disease, recruited through either active (n = 1,095) or passive (n = 12,453) surveillance. The sensitivity was 52% and 56%, the specificity was 58% and 68%, the positive predictive value was 45% and 55%, and the negative predictive value was 64% and 69% for persons enrolled in active and passive surveillance, respectively. We demonstrated that the TT was more sensitive identifying dengue disease in women and those of younger age and that sensitivity increased the later a person came to a medical clinic for care. PMID:23716410

  16. Performance of the tourniquet test for diagnosing dengue in Peru.

    PubMed

    Halsey, Eric S; Vilcarromero, Stalin; Forshey, Brett M; Rocha, Claudio; Bazan, Isabel; Stoddard, Steven T; Kochel, Tadeusz J; Casapia, Martin; Scott, Thomas W; Morrison, Amy C

    2013-07-01

    The tourniquet test (TT) is a physical examination maneuver often performed on patients suspected of having dengue. It has been incorporated into dengue diagnostic guidelines and is used in clinical studies. However, little is known about TT performance characteristics in different patient types or epidemiologic conditions. In the dengue-endemic city of Iquitos, Peru, we performed TTs and dengue laboratory assays on 13,548 persons with febrile disease, recruited through either active (n = 1,095) or passive (n = 12,453) surveillance. The sensitivity was 52% and 56%, the specificity was 58% and 68%, the positive predictive value was 45% and 55%, and the negative predictive value was 64% and 69% for persons enrolled in active and passive surveillance, respectively. We demonstrated that the TT was more sensitive identifying dengue disease in women and those of younger age and that sensitivity increased the later a person came to a medical clinic for care.

  17. Analysis of Dengue Virus Enhancing Epitopes Using Peptide Antigens Derived From the Envelope Glycoprotein Gene Sequence.

    DTIC Science & Technology

    1991-11-29

    AD-A261 707 AD____ ARMY PROJECT ORDER NO: 89PP9961 TITLE: ANALYSIS OF DENGUE VIRUS ENHANCING EPITOPES USING PEPTIDE ANTIGENS DERIVED FROM THE...DATES COVERED 29 Nov 91 Final Report (9/1/89 - 11/30/91) 4. TITLE AND SUBTITLE Ana ysis or Dengue Vnrus nancing 5. FUNDING NUMBERS Epitopes Using...biological events leading to the development of severe disease manifestations of dengue infections ( dengue hemorrhagic fever/ dengue shock syndrome

  18. Upper gastrointestinal haemorrhage in severe dengue: To scope or not to scope?

    PubMed

    Lim, C H; Benjamin, N H S; Kan, F K

    2017-02-01

    Upper gastrointestinal haemorrhage (UGIH) in severe dengue represents a clinical dilemma in term of management. The recommended treatment in dengue with UGIH involves blood product transfusion support and proton pump inhibitor (PPI) infusion. Despite being the mainstay of treatment in non-dengue UGIH, the role of endoscopic haemostatic intervention in severe dengue remains controversial. In the present report, we present a case of severe dengue complicated with upper gastrointestinal haemorrhage successfully underwent early therapeutic endoscopic intervention in a district hospital.

  19. Preparing for introduction of a dengue vaccine: recommendations from the 1st Dengue v2V Asia-Pacific Meeting.

    PubMed

    Lam, Sai Kit; Burke, Donald; Capeding, Maria Rosario; Chong, Chee Keong; Coudeville, Laurent; Farrar, Jeremy; Gubler, Duane; Hadinegoro, Sri Rezeki; Hanna, Jeffrey; Lang, Jean; Lee, Han Lim; Leo, Yee Sin; Luong, Chan Quang; Mahoney, Richard; McBride, John; Mendez-Galvan, Jorge; Ng, Lee Ching; Nimmannitya, Suchitra; Ooi, Eng Eong; Shepard, Donald; Smit, Jaco; Teyssou, Rémy; Thomas, Laurent; Torresi, Joseph; Vasconcelos, Pedro; Wirawan, Dewa Nyoman; Yoksan, Sutee

    2011-11-28

    Infection with dengue virus is a major public health problem in the Asia-Pacific region and throughout tropical and sub-tropical regions of the world. Vaccination represents a major opportunity to control dengue and several candidate vaccines are in development. Experts in dengue and in vaccine introduction gathered for a two day meeting during which they examined the challenges inherent to the introduction of a dengue vaccine into the national immunisation programmes of countries of the Asia-Pacific. The aim was to develop a series of recommendations to reduce the delay between vaccine licensure and vaccine introduction. Major recommendations arising from the meeting included: ascertaining and publicising the full burden and cost of dengue; changing the perception of dengue in non-endemic countries to help generate global support for dengue vaccination; ensuring high quality active surveillance systems and diagnostics; and identifying sustainable sources of funding, both to support vaccine introduction and to maintain the vaccination programme. The attendees at the meeting were in agreement that with the introduction of an effective vaccine, dengue is a disease that could be controlled, and that in order to ensure a vaccine is introduced as rapidly as possible, there is a need to start preparing now.

  20. [Coexistence of acute appendicitis and dengue fever: A case report].

    PubMed

    Osuna-Ramos, Juan Fidel; Silva-Gracia, Carlos; Maya-Vacio, Gerardo Joel; Romero-Utrilla, Alejandra; Ríos-Burgueño, Efrén Rafael; Velarde-Félix, Jesús Salvador

    2017-01-03

    Dengue is the most important human viral disease transmitted by mosquitoes. It can be asymptomatic or it can present in any of its 3clinical forms: Dengue fever, dengue haemorrhagic fever and dengue shock syndrome. However, some atypical manifestations have been reported in surgical emergencies caused by acute appendicitis in patients with dengue fever. We report the case of an 18-year-old Mexican male who presented to the emergency department of the General Hospital of Culiacan, Sinaloa, with symptoms of dengue fever, accompanied by crampy abdominal pain with positive Rovsing and Dunphy signs. Dengue infection was confirmed by a positive NS1 antigen test performed by enzyme-linked immunosorbent assay. An abdominal ultrasound revealed an appendicular process; as the abdominal pain in the right side kept increasing, an open appendectomy was performed. Abundant inflammatory liquid was observed during the surgery, and the pathology laboratory reported an oedematous appendix with fibrinopurulent plaques, which agreed with acute ulcerative appendicitis. The patient was discharged fully recovered without complications during the follow-up period. Acute abdominal pain can be caused in some cases by dengue infection. This can be confusing, which can lead to unnecessary surgical interventions, creating additional morbidities and costs for the patient. This unusual and coincident acute appendicitis with dengue highlights the importance of performing careful clinical studies for appropriate decision making, especially in dengue endemic regions during an outbreak of this disease. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

  1. Evaluation of dengue fever reports during an epidemic, Colombia.

    PubMed

    Romero-Vega, Liliana; Pacheco, Oscar; de la Hoz-Restrepo, Fernando; Díaz-Quijano, Fredi Alexander

    2014-12-01

    OBJECTIVE To assess the validity of dengue fever reports and how they relate to the definition of case and severity. METHODS Diagnostic test assessment was conducted using cross-sectional sampling from a universe of 13,873 patients treated during the fifth epidemiological period in health institutions from 11 Colombian departments in 2013. The test under analyses was the reporting to the National Public Health Surveillance System, and the reference standard was the review of histories identified by active institutional search. We reviewed all histories of patients diagnosed with dengue fever, as well as a random sample of patients with febrile syndromes. The specificity and sensitivity of reports were estimated for this purpose, considering the inverse of the probability of being selected for weighting. The concordance between reporting and the findings of the active institutional search was calculated using Kappa statistics. RESULTS We included 4,359 febrile patients, and 31.7% were classified as compatible with dengue fever (17 with severe dengue fever; 461 with dengue fever and warning signs; 904 with dengue fever and no warning signs). The global sensitivity of reports was 13.2% (95%CI 10.9;15.4) and specificity was 98.4% (95%CI 97.9;98.9). Sensitivity varied according to severity: 12.1% (95%CI 9.3;14.8) for patients presenting dengue fever with no warning signs; 14.5% (95%CI 10.6;18.4) for those presenting dengue fever with warning signs, and 40.0% (95%CI 9.6;70.4) for those with severe dengue fever. Concordance between reporting and the findings of the active institutional search resulted in a Kappa of 10.1%. CONCLUSIONS Low concordance was observed between reporting and the review of clinical histories, which was associated with the low reporting of dengue fever compatible cases, especially milder cases.

  2. Platelet activation and apoptosis modulate monocyte inflammatory responses in dengue

    PubMed Central

    Hottz, Eugenio D.; Medeiros-de-Moraes, Isabel M.; Vieira-de-Abreu, Adriana; de Assis, Edson F.; Vals-de-Souza, Rogério; Castro-Faria-Neto, Hugo C.; Weyrich, Andrew S.; Zimmerman, Guy A.; Bozza, Fernando A.; Bozza, Patrícia T.

    2014-01-01

    Background Dengue is the most prevalent human arbovirus disease in the world. Dengue infection has a large spectrum of clinical manifestations from self-limited febrile illness to severe syndromes accompanied by bleeding and shock. Thrombocytopenia and vascular leak with altered cytokine profiles in plasma are features of severe dengue. Although monocytes have been recognized as important sources of cytokines in dengue, the contributions of platelet-monocyte interactions to inflammatory responses in dengue have not been addressed. Patients/Methods Patients with dengue were investigated for platelet-monocyte aggregate formation and markers of monocyte activation. Platelet-induced cytokine responses by monocytes and underlying mechanisms were also investigated in vitro. Results We observed increased levels of platelet-monocyte aggregates in blood samples from patients with dengue, especially patients with thrombocytopenia and increased vascular permeability. Moreover, the exposure of monocytes from healthy volunteers to platelets from patients with dengue induced the secretion of the cytokines IL-1β, IL-8, IL-10 and MCP-1, while the exposure to platelets from healthy volunteers only induced the secretion of MCP-1. In addition to the well-established modulation of monocyte cytokine responses by activated platelets through P-selectin binding, we found that interaction of monocytes with apoptotic platelets mediate IL-10 secretion through phosphatidylserine recognition in platelet-monocyte aggregates. Moreover, IL-10 secretion required platelet-monocyte contact but not phagocytosis. Conclusions Together, our results demonstrate that activated and apoptotic platelets aggregate with monocytes during dengue infection and signal specific cytokine responses that may contribute to the pathogenesis of dengue. PMID:25015827

  3. Analysis of significant factors for dengue fever incidence prediction.

    PubMed

    Siriyasatien, Padet; Phumee, Atchara; Ongruk, Phatsavee; Jampachaisri, Katechan; Kesorn, Kraisak

    2016-04-16

    Many popular dengue forecasting techniques have been used by several researchers to extrapolate dengue incidence rates, including the K-H model, support vector machines (SVM), and artificial neural networks (ANN). The time series analysis methodology, particularly ARIMA and SARIMA, has been increasingly applied to the field of epidemiological research for dengue fever, dengue hemorrhagic fever, and other infectious diseases. The main drawback of these methods is that they do not consider other variables that are associated with the dependent variable. Additionally, new factors correlated to the disease are needed to enhance the prediction accuracy of the model when it is applied to areas of similar climates, where weather factors such as temperature, total rainfall, and humidity are not substantially different. Such drawbacks may consequently lower the predictive power for the outbreak. The predictive power of the forecasting model-assessed by Akaike's information criterion (AIC), Bayesian information criterion (BIC), and the mean absolute percentage error (MAPE)-is improved by including the new parameters for dengue outbreak prediction. This study's selected model outperforms all three other competing models with the lowest AIC, the lowest BIC, and a small MAPE value. The exclusive use of climate factors from similar locations decreases a model's prediction power. The multivariate Poisson regression, however, effectively forecasts even when climate variables are slightly different. Female mosquitoes and seasons were strongly correlated with dengue cases. Therefore, the dengue incidence trends provided by this model will assist the optimization of dengue prevention. The present work demonstrates the important roles of female mosquito infection rates from the previous season and climate factors (represented as seasons) in dengue outbreaks. Incorporating these two factors in the model significantly improves the predictive power of dengue hemorrhagic fever forecasting

  4. A rare case of dengue encephalopathy complicating a term pregnancy.

    PubMed

    Rajagopala, Lavanya; Satharasinghe, Ravindra L; Karunarathna, Madhava

    2017-02-02

    Dengue fever has an expanded clinical spectrum ranging from an asymptomatic infection to life threatening dengue hemorrhagic fever and refractory shock. Dengue infection in pregnancy can be a diagnostic dilemma, particularly considering the physiological changes in pregnancy and the obstetric complications encountered in clinical practice. Hence the knowledge of its diagnosis and management in its atypical presentations is of paramount importance. Here we report an unusual case of uncomplicated dengue encephalopathy in a term mother, probably the first to be reported from the Indian subcontinent. A 28 year old woman, 37 weeks of pregnancy presented with fever of four days duration. She eventually developed irritability, altered sensorium, somnolence, and unresponsiveness to commands by the 5th day of febrile illness without any circulatory compromise. Physical examination and investigations including serology confirmed dengue fever. After excluding all other possible causes, the transient neurological deterioration was finally attributed to dengue encephalopathy which is an uncommon manifestation of the disease, particularly in pregnancy. Her deteriorated neurological status which had lasted for 6 days improved spontaneously with the convalescence of dengue infection. Cautious fluid management was carried out in correlation to clinical and hematological parameters. The pregnancy was continued uncomplicated till the platelet count had risen to more than 50,000 cells/cumm. She delivered vaginally a healthy male baby. Dengue fever in pregnancy is increasingly being encountered due to its rising disease burden. Dengue encephalitis/encephalopathy must be suspected in the differential diagnosis of fever and altered sensorium, even in pregnancy, in the tropical countries where the infection is rampant. Management of dengue infection in term pregnancy is a challenge for both the clinician and obstetrician. Further discussion and research are mandatory to decide on

  5. Dengue and soluble mediators of the innate immune system.

    PubMed

    Espada-Murao, Lyre Anni; Morita, Kouichi

    2011-12-01

    Huge emphasis has been placed on the role of the adaptive immune system in dengue pathogenesis. Yet there is increasing evidence for the importance of the innate immune system in regulating dengue infection and possibly influencing the disease. This review focuses on the interplay between the innate immune system and dengue and highlights the role of soluble immunological mediators. Type I and type II interferons of the innate immune system demonstrate non-overlapping roles in dengue infection. Furthermore, while some IFN responses to dengue are protective, others may exert disease-related effects on the host. But aside from interferons, a number of cytokines have also been implicated in dengue pathogenesis. Our expanding knowledge of cytokines indicates that these soluble mediators act upon a complicated network of events to provoke the disease. This cytokine storm is generally attributed to massive T cell activation as an outcome of secondary infection. However, there is reason to believe that innate immune response-derived cytokines also have contributory effects, especially in the context of severe cases of primary dengue infection. Another less popular but interesting perspective on dengue pathogenesis is the effect of mosquito feeding on host immune responses and viral infection. Various studies have shown that soluble factors from vector saliva have the capacity to alter immune reactions and thereby influence pathogen transmission and establishment. Hence, modulation of the innate immune system at various levels of infection is a critical component of dengue disease. In the absence of an approved drug or vaccine for dengue, soluble mediators of the innate immune system could be a strategic foothold for developing anti-viral therapeutics and improving clinical management.

  6. Evaluation of dengue fever reports during an epidemic, Colombia

    PubMed Central

    Romero-Vega, Liliana; Pacheco, Oscar; de la Hoz-Restrepo, Fernando; Díaz-Quijano, Fredi Alexander

    2014-01-01

    OBJECTIVE To assess the validity of dengue fever reports and how they relate to the definition of case and severity. METHODS Diagnostic test assessment was conducted using cross-sectional sampling from a universe of 13,873 patients treated during the fifth epidemiological period in health institutions from 11 Colombian departments in 2013. The test under analyses was the reporting to the National Public Health Surveillance System, and the reference standard was the review of histories identified by active institutional search. We reviewed all histories of patients diagnosed with dengue fever, as well as a random sample of patients with febrile syndromes. The specificity and sensitivity of reports were estimated for this purpose, considering the inverse of the probability of being selected for weighting. The concordance between reporting and the findings of the active institutional search was calculated using Kappa statistics. RESULTS We included 4,359 febrile patients, and 31.7% were classified as compatible with dengue fever (17 with severe dengue fever; 461 with dengue fever and warning signs; 904 with dengue fever and no warning signs). The global sensitivity of reports was 13.2% (95%CI 10.9;15.4) and specificity was 98.4% (95%CI 97.9;98.9). Sensitivity varied according to severity: 12.1% (95%CI 9.3;14.8) for patients presenting dengue fever with no warning signs; 14.5% (95%CI 10.6;18.4) for those presenting dengue fever with warning signs, and 40.0% (95%CI 9.6;70.4) for those with severe dengue fever. Concordance between reporting and the findings of the active institutional search resulted in a Kappa of 10.1%. CONCLUSIONS Low concordance was observed between reporting and the review of clinical histories, which was associated with the low reporting of dengue fever compatible cases, especially milder cases. PMID:26039392

  7. Cloning and application of recombinant dengue virus prM-M protein for serodiagnosis of dengue virus infection.

    PubMed

    Wichit, Sineewanlaya; Yongpradoem, Hatairat; Surasombatpattana, Pornapat; Leaungwuttiwong, Pornsawan; Kalambaheti, Thareerat; Jampangern, Wipawee; Jittmittraphap, Akanitt

    2013-03-01

    We studied the use of the precursor to the M structural protein (prM) found only on the surface of mature dengue virus as a target protein to detect dengue virus infection. Recombinant D2-16681 prM-M protein was constructed and tested for immunogenicity with dengue and Japanese encephalitis patient sera by Western blot analysis and indirect ELISA. The sensitivity and specificity of indirect ELISA were 48.1 and 85.5%, respectively, and Western blot assay were 23.1 and 98.7%, respectively, for detection of dengue virus. Although the sensitivity of the indirect ELISA is low, the indirect ELISA using recombinant D2-16681 prM-M proteins as antigen may be used for early detection of dengue virus infection.

  8. Pediatric measles vaccine expressing a dengue tetravalent antigen elicits neutralizing antibodies against all four dengue viruses.

    PubMed

    Brandler, Samantha; Ruffie, Claude; Najburg, Valérie; Frenkiel, Marie-Pascale; Bedouelle, Hughes; Desprès, Philippe; Tangy, Frédéric

    2010-09-24

    Dengue disease is an increasing global health problem that threatens one-third of the world's population. To control this emerging arbovirus, an efficient preventive vaccine is still needed. Because four serotypes of dengue virus (DV) coexist and antibody-dependent enhanced infection may occur, most strategies developed so far rely on the administration of tetravalent formulations of four live attenuated or chimeric viruses. Here, we evaluated a new strategy based on the expression of a single minimal tetravalent DV antigen by a single replicating viral vector derived from pediatric live-attenuated measles vaccine (MV). We generated a recombinant MV vector expressing a DV construct composed of the four envelope domain III (EDIII) from the four DV serotypes fused with the ectodomain of the membrane protein (ectoM). After two injections in mice susceptible to MV infection, the recombinant vector induced neutralizing antibodies against the four serotypes of dengue virus. When immunized mice were further inoculated with live DV from each serotype, a strong memory neutralizing response was raised against all four serotypes. A combined measles-dengue vaccine might be attractive to immunize infants against both diseases where they co-exist.

  9. Analysis of Dengue Serotype 4 in Sri Lanka during the 2012-2013 Dengue Epidemic.

    PubMed

    Uehara, Anna; Tissera, Hasitha Aravinda; Bodinayake, Champica K; Amarasinghe, Ananda; Nagahawatte, Ajith; Tillekeratne, L Gayani; Cui, Jie; Reller, Megan E; Palihawadana, Paba; Gunasena, Sunethra; Desilva, Aruna Dharshan; Wilder-Smith, Annelies; Gubler, Duane J; Woods, Christopher W; Sessions, October M

    2017-07-01

    The four serotypes of dengue virus (DENV-1, -2, -3, and -4) have had a rapidly expanding geographic range and are now endemic in over 100 tropical and subtropical countries. Sri Lanka has experienced periodic dengue outbreaks since the 1960s, but since 1989 epidemics have become progressively larger and associated with more severe disease. The dominant virus in the 2012 epidemic was DENV-1, but DENV-4 infections were also commonly observed. DENV-4 transmission was first documented in Sri Lanka when it was isolated from a traveler in 1978, but has been comparatively uncommon since dengue surveillance began in the early 1980s. To better understand the molecular epidemiology of DENV-4 infections in Sri Lanka, we conducted whole-genome sequencing on dengue patient samples from two different geographic locations. Phylogenetic analysis indicates that all sequenced DENV-4 strains belong to genotype 1 and are most closely related to DENV-4 viruses previously found in Sri Lanka and those recently found to be circulating in India and Pakistan.

  10. Monoclonal Antibodies for Dengue Virus prM Glycoprotein Protect Mice against Lethal Dengue Infection

    DTIC Science & Technology

    1989-09-15

    Nile virus and a prelysozomal endosome prM glycoprotein of dengue virus can also be required for viral replication . PrM Mabs 2H2 protective against...tech- bodies can prevent lethal alphavirus encepha- niques to preserve immunogenicity, to deter- litis. Nature 297: 70-72. UI:82173237 mine whether

  11. Molecular surveillance of dengue in Semarang, Indonesia revealed the circulation of an old genotype of dengue virus serotype-1.

    PubMed

    Fahri, Sukmal; Yohan, Benediktus; Trimarsanto, Hidayat; Sayono, S; Hadisaputro, Suharyo; Dharmana, Edi; Syafruddin, Din; Sasmono, R Tedjo

    2013-01-01

    Dengue disease is currently a major health problem in Indonesia and affects all provinces in the country, including Semarang Municipality, Central Java province. While dengue is endemic in this region, only limited data on the disease epidemiology is available. To understand the dynamics of dengue in Semarang, we conducted clinical, virological, and demographical surveillance of dengue in Semarang and its surrounding regions in 2012. Dengue cases were detected in both urban and rural areas located in various geographical features, including the coastal and highland areas. During an eight months' study, a total of 120 febrile patients were recruited, of which 66 were serologically confirmed for dengue infection using IgG/IgM ELISA and/or NS1 tests. The cases occurred both in dry and wet seasons. Majority of patients were under 10 years old. Most patients were diagnosed as dengue hemorrhagic fever, followed by dengue shock syndrome and dengue fever. Serotyping was performed in 31 patients, and we observed the co-circulation of all four dengue virus (DENV) serotypes. When the serotypes were correlated with the severity of the disease, no direct correlation was observed. Phylogenetic analysis of DENV based on Envelope gene sequence revealed the circulation of DENV-2 Cosmopolitan genotype and DENV-3 Genotype I. A striking finding was observed for DENV-1, in which we found the co-circulation of Genotype I with an old Genotype II. The Genotype II was represented by a virus strain that has a very slow mutation rate and is very closely related to the DENV strain from Thailand, isolated in 1964 and never reported in other countries in the last three decades. Moreover, this virus was discovered in a cool highland area with an elevation of 1,001 meters above the sea level. The discovery of this old DENV strain may suggest the silent circulation of old virus strains in Indonesia.

  12. Molecular Surveillance of Dengue in Semarang, Indonesia Revealed the Circulation of an Old Genotype of Dengue Virus Serotype-1

    PubMed Central

    Trimarsanto, Hidayat; Sayono, S.; Hadisaputro, Suharyo; Dharmana, Edi; Syafruddin, Din; Sasmono, R. Tedjo

    2013-01-01

    Dengue disease is currently a major health problem in Indonesia and affects all provinces in the country, including Semarang Municipality, Central Java province. While dengue is endemic in this region, only limited data on the disease epidemiology is available. To understand the dynamics of dengue in Semarang, we conducted clinical, virological, and demographical surveillance of dengue in Semarang and its surrounding regions in 2012. Dengue cases were detected in both urban and rural areas located in various geographical features, including the coastal and highland areas. During an eight months' study, a total of 120 febrile patients were recruited, of which 66 were serologically confirmed for dengue infection using IgG/IgM ELISA and/or NS1 tests. The cases occurred both in dry and wet seasons. Majority of patients were under 10 years old. Most patients were diagnosed as dengue hemorrhagic fever, followed by dengue shock syndrome and dengue fever. Serotyping was performed in 31 patients, and we observed the co-circulation of all four dengue virus (DENV) serotypes. When the serotypes were correlated with the severity of the disease, no direct correlation was observed. Phylogenetic analysis of DENV based on Envelope gene sequence revealed the circulation of DENV-2 Cosmopolitan genotype and DENV-3 Genotype I. A striking finding was observed for DENV-1, in which we found the co-circulation of Genotype I with an old Genotype II. The Genotype II was represented by a virus strain that has a very slow mutation rate and is very closely related to the DENV strain from Thailand, isolated in 1964 and never reported in other countries in the last three decades. Moreover, this virus was discovered in a cool highland area with an elevation of 1,001 meters above the sea level. The discovery of this old DENV strain may suggest the silent circulation of old virus strains in Indonesia. PMID:23951374

  13. NF90 Binds the Dengue Virus RNA 3′ Terminus and Is a Positive Regulator of Dengue Virus Replication

    PubMed Central

    Gehrke, Lee

    2011-01-01

    Background Viral RNA translation and replication are regulated by sequence and structural elements in the 5′ and 3′ untranslated regions (UTR) and by host cell and/or viral proteins that bind them. Dengue virus has a single-stranded RNA genome with positive polarity, a 5′ m7GpppG cap, and a conserved 3′-terminal stem loop (SL) that is linked to proposed functions in viral RNA transcription and translation. Mechanisms explaining the contributions of host proteins to viral RNA translation and replication are poorly defined, yet understanding host protein-viral RNA interactions may identify new targets for therapeutic intervention. This study was directed at identifying functionally significant host proteins that bind the conserved dengue virus RNA 3′ terminus. Methodology/Principal Findings Proteins eluted from a dengue 3′ SL RNA affinity column at increasing ionic strength included two with double-strand RNA binding motifs (NF90/DRBP76 and DEAH box polypeptide 9/RNA helicase A (RHA)), in addition to NF45, which forms a heterodimer with NF90. Although detectable NF90 and RHA proteins localized to the nucleus of uninfected cells, immunofluorescence revealed cytoplasmic NF90 in dengue virus-infected cells, leading us to hypothesize that NF90 has a functional role(s) in dengue infections. Cells depleted of NF90 were used to quantify viral RNA transcript levels and production of infectious dengue virus. NF90 depletion was accompanied by a 50%-70% decrease in dengue RNA levels and in production of infectious viral progeny. Conclusions/Significance The results indicate that NF90 interacts with the 3′ SL structure of the dengue RNA and is a positive regulator of dengue virus replication. NF90 depletion diminished the production of infectious dengue virus by more than 50%, which may have important significance for identifying therapeutic targets to limit a virus that threatens more than a billion people worldwide. PMID:21386893

  14. Evaluation of dengue virus strains for human challenge studies.

    PubMed

    Mammen, M P; Lyons, A; Innis, B L; Sun, W; McKinney, D; Chung, R C Y; Eckels, K H; Putnak, R; Kanesa-thasan, N; Scherer, J M; Statler, J; Asher, L V; Thomas, S J; Vaughn, D W

    2014-03-14

    Discordance between the measured levels of dengue virus neutralizing antibody and clinical outcomes in the first-ever efficacy study of a dengue tetravalent vaccine (Lancet, Nov 2012) suggests a need to re-evaluate the process of pre-screening dengue vaccine candidates to better predict clinical benefit prior to large-scale vaccine trials. In the absence of a reliable animal model and established correlates of protection for dengue, a human dengue virus challenge model may provide an approach to down-select vaccine candidates based on their ability to reduce risk of illness following dengue virus challenge. We report here the challenge of flavivirus-naïve adults with cell culture-passaged dengue viruses (DENV) in a controlled setting that resulted in uncomplicated dengue fever (DF). This sets the stage for proof-of-concept efficacy studies that allow the evaluation of dengue vaccine candidates in healthy adult volunteers using qualified DENV challenge strains well before they reach field efficacy trials involving children. Fifteen flavivirus-naïve adult volunteers received 1 of 7 DENV challenge strains (n=12) or placebo (n=3). Of the twelve volunteers who received challenge strains, five (two DENV-1 45AZ5 and three DENV-3 CH53489 cl24/28 recipients) developed DF, prospectively defined as ≥2 typical symptoms, ≥48h of sustained fever (>100.4°F) and concurrent viremia. Based on our study and historical data, we conclude that the DENV-1 and DENV-3 strains can be advanced as human challenge strains. Both of the DENV-2 strains and one DENV-4 strain failed to meet the protocol case definition of DF. The other two DENV-4 strains require additional testing as the illness approximated but did not satisfy the case definition of DF. Three volunteers exhibited effusions (1 pleural/ascites, 2 pericardial) and 1 volunteer exhibited features of dengue (rash, lymphadenopathy, neutropenia and thrombocytopenia), though in the absence of fever and symptoms. The occurrence of

  15. The dengue and dengue hemorrhagic fever epidemic in Puerto Rico, 1994-1995.

    PubMed

    Rigau-Pérez, J G; Vorndam, A V; Clark, G G

    2001-01-01

    From June 1, 1994 to May 31, 1995 a total of 24,700 cases of dengue (7.01/1,000 population) were reported to the laboratory-based surveillance system in Puerto Rico (1991-1994, annual average: 2.55/1,000). Dengue virus 2 predominated. The earliest indicator of epidemic activity was the virus isolation rate in May 1994 (14.0% versus 5.7% average). The male-to-female ratio among cases was 1:1.1; 65.4% were younger than 30 years (the 10 to 19 year age group had the highest incidence, 11.8/1,000). At least 5,687 cases (23.0%) showed a hemorrhagic manifestation; 4,662 (18.9%) were hospitalized, and 40 died (0.2%; 10 laboratory-positive). Two cases documented by laboratory were transmitted by unusual routes--intrapartum and through a bone marrow transplant. Among 2,004 hospitalized cases reported by infection control nurses, 139 (6.9%) fulfilled the criteria for dengue hemorrhagic fever (DHF) and another 13 cases (0.6%) had dengue shock syndrome. This epidemic produced the largest number of hospitalizations, DHF cases, and deaths from any dengue epidemic in Puerto Rico. Severity did not change throughout the year. Surveillance capabilities were maintained by temporary, simplified reporting methods, none of which could be recommended as the single method of choice for surveillance; each must be used (on site, or as a service available from a reference laboratory) at the right time in the epidemic cycle. The utility of comparisons of current and previous data underscores the value of long-term surveillance. Our analysis was unable to document whether significantly increased transmission occurred more often in cities where the water supply was rationed or where the local landfill was closed.

  16. Developing a Time Series Predictive Model for Dengue in Zhongshan, China Based on Weather and Guangzhou Dengue Surveillance Data.

    PubMed

    Zhang, Yingtao; Wang, Tao; Liu, Kangkang; Xia, Yao; Lu, Yi; Jing, Qinlong; Yang, Zhicong; Hu, Wenbiao; Lu, Jiahai

    2016-02-01

    Dengue is a re-emerging infectious disease of humans, rapidly growing from endemic areas to dengue-free regions due to favorable conditions. In recent decades, Guangzhou has again suffered from several big outbreaks of dengue; as have its neighboring cities. This study aims to examine the impact of dengue epidemics in Guangzhou, China, and to develop a predictive model for Zhongshan based on local weather conditions and Guangzhou dengue surveillance information. We obtained weekly dengue case data from 1st January, 2005 to 31st December, 2014 for Guangzhou and Zhongshan city from the Chinese National Disease Surveillance Reporting System. Meteorological data was collected from the Zhongshan Weather Bureau and demographic data was collected from the Zhongshan Statistical Bureau. A negative binomial regression model with a log link function was used to analyze the relationship between weekly dengue cases in Guangzhou and Zhongshan, controlling for meteorological factors. Cross-correlation functions were applied to identify the time lags of the effect of each weather factor on weekly dengue cases. Models were validated using receiver operating characteristic (ROC) curves and k-fold cross-validation. Our results showed that weekly dengue cases in Zhongshan were significantly associated with dengue cases in Guangzhou after the treatment of a 5 weeks prior moving average (Relative Risk (RR) = 2.016, 95% Confidence Interval (CI): 1.845-2.203), controlling for weather factors including minimum temperature, relative humidity, and rainfall. ROC curve analysis indicated our forecasting model performed well at different prediction thresholds, with 0.969 area under the receiver operating characteristic curve (AUC) for a threshold of 3 cases per week, 0.957 AUC for a threshold of 2 cases per week, and 0.938 AUC for a threshold of 1 case per week. Models established during k-fold cross-validation also had considerable AUC (average 0.938-0.967). The sensitivity and specificity

  17. Developing a Time Series Predictive Model for Dengue in Zhongshan, China Based on Weather and Guangzhou Dengue Surveillance Data

    PubMed Central

    Liu, Kangkang; Xia, Yao; Lu, Yi; Jing, Qinlong; Yang, Zhicong; Hu, Wenbiao; Lu, Jiahai

    2016-01-01

    Background Dengue is a re-emerging infectious disease of humans, rapidly growing from endemic areas to dengue-free regions due to favorable conditions. In recent decades, Guangzhou has again suffered from several big outbreaks of dengue; as have its neighboring cities. This study aims to examine the impact of dengue epidemics in Guangzhou, China, and to develop a predictive model for Zhongshan based on local weather conditions and Guangzhou dengue surveillance information. Methods We obtained weekly dengue case data from 1st January, 2005 to 31st December, 2014 for Guangzhou and Zhongshan city from the Chinese National Disease Surveillance Reporting System. Meteorological data was collected from the Zhongshan Weather Bureau and demographic data was collected from the Zhongshan Statistical Bureau. A negative binomial regression model with a log link function was used to analyze the relationship between weekly dengue cases in Guangzhou and Zhongshan, controlling for meteorological factors. Cross-correlation functions were applied to identify the time lags of the effect of each weather factor on weekly dengue cases. Models were validated using receiver operating characteristic (ROC) curves and k-fold cross-validation. Results Our results showed that weekly dengue cases in Zhongshan were significantly associated with dengue cases in Guangzhou after the treatment of a 5 weeks prior moving average (Relative Risk (RR) = 2.016, 95% Confidence Interval (CI): 1.845–2.203), controlling for weather factors including minimum temperature, relative humidity, and rainfall. ROC curve analysis indicated our forecasting model performed well at different prediction thresholds, with 0.969 area under the receiver operating characteristic curve (AUC) for a threshold of 3 cases per week, 0.957 AUC for a threshold of 2 cases per week, and 0.938 AUC for a threshold of 1 case per week. Models established during k-fold cross-validation also had considerable AUC (average 0.938–0.967). The

  18. Travel-associated Dengue surveillance - United States, 2006-2008.

    PubMed

    2010-06-18

    Dengue is caused by four antigenically related viruses (DENV-1, DENV-2, DENV-3, and DENV-4). Dengue fever is endemic in most tropical and subtropical areas of the world, and in 2007 nearly 1 million cases were reported in the Americas alone. Dengue infections commonly occur among U.S. residents returning from travel to endemic areas and are more prevalent than malaria among returning travelers from the Caribbean, South America, South Central Asia, and Southeast Asia. This report summarizes information about dengue cases reported to CDC through two CDC-maintained passive surveillance systems: 1) the ArboNET surveillance system, a national CDC arboviral surveillance system maintained by CDC's Arboviral Diseases Branch and initially developed in response to the introduction of West Nile virus in the United States, and 2) a system maintained for decades by the CDC Dengue Branch (CDCDB), which collects information on all suspected dengue cases whose specimens are sent to the branch. During 2006-2008, a total of 1,125 unique reports were made to either ArboNET or CDCDB. Of these, the highest proportion of laboratory-confirmed and probable cases with known travel histories were in persons who reported travel to the Dominican Republic (121; 20%), Mexico (55; 9%), and India (43; 7%). Health-care providers should consider dengue in the differential diagnosis of patients with a history of travel to endemic areas within 14 days of fever onset.

  19. Value of routine dengue diagnosis in endemic countries.

    PubMed

    Ayukekbong, James Ayukepi; Oyero, Olufunmilayo G; Nnukwu, Samuel Ekpesu; Mesumbe, Henry Nzike; Fobisong, Cajetang Nkong

    2017-02-12

    Dengue is one of the most common arthropod-borne viral diseases in humans and it is a leading cause of illness and death in the tropical and subtropical regions of the world. It is thought to account for 400 million cases annually among approximately 3.97 billion people at risk of infection in 128 endemic countries. Despite the global prevalence of the disease, the availability of a vaccine is limited in most countries in the endemic areas. Most endemic countries in South America, South East Asia and Africa serve as attractive touristic sites for people from non-endemic countries who become infected and export the virus to dengue-free regions. Dengue fever typically resembles malaria and in endemic countries most cases of dengue are treated as presumptive malaria. Consequently, routine dengue diagnosis among persons with fever will offer early treatment and reduce the burden of the disease. Also, routine testing among travellers from endemic countries will reduce importation and prevent the geographical expansion of dengue. In this essay, we seek to highlight the usefulness of routine dengue testing in endemic countries.

  20. Heart and Skeletal Muscle Are Targets of Dengue Virus Infection

    PubMed Central

    Salgado, Doris Martha; Eltit, José Miguel; Mansfield, Keith; Panqueba, César; Castro, Dolly; Vega, Martha Rocio; Xhaja, Kris; Schmidt, Diane; Martin, Katherine J.; Allen, Paul D.; Rodriguez, Jairo Antonio; Dinsmore, Jonathan H.; López, José Rafael; Bosch, Irene

    2010-01-01

    Background Dengue fever is one of the most significant re-emerging tropical diseases, despite our expanding knowledge of the disease, viral tropism is still not known to target heart tissues or muscle. Methods A prospective pediatric clinical cohort of 102 dengue hemorrhagic fever patients from Colombia, South America, was followed for 1 year. Clinical diagnosis of myocarditis was routinely performed. Electrocardiograph and echocardiograph analysis were performed to confirm those cases. Immunohistochemistry for detection of dengue virus and inflammatory markers was performed on autopsied heart tissue. In vitro studies of human striated skeletal fibers (myotubes) infected with dengue virus were used as a model for myocyte infection. Measurements of intracellular Ca2+ concentration as well as immunodetection of dengue virus and inflammation markers in infected myotubes were performed. Results Eleven children with dengue hemorrhagic fever presented with symptoms of myocarditis. Widespread viral infection of the heart, myocardial endothelium, and cardiomyocytes, accompanied by inflammation was observed in 1 fatal case. Immunofluorescence confocal microscopy showed that myotubes were infected by dengue virus and had increased expression of the inflammatory genes and protein IP-10. The infected myotubes also had increases in intracellular Ca2+ concentration. Conclusions Vigorous infection of heart tissues in vivo and striated skeletal cells in vitro are demonstrated. Derangements of Ca2+ storage in the infected cells may directly contribute to the presentation of myocarditis in pediatric patients. PMID:20032806

  1. Quality of life among adults with confirmed dengue in Brazil.

    PubMed

    Martelli, Celina Maria Turchi; Nascimento, Nazareth Elias; Suaya, Jose A; Siqueira, Joao Bosco; Souza, Wayner Vieira; Turchi, Marilia Dalva; Guilarde, Adriana Oliveira; Peres, Joao Borges; Shepard, Donald S

    2011-10-01

    The main objective of this study was to measure the quality of life (QoL) during a dengue episode. We conducted a facility-based survey in central Brazil in 2005 and recruited 372 laboratory-confirmed dengue patients greater than 12 years of age in hospital and ambulatory settings. We administered the World Health Organization QoL instrument approximately 15 days after the onset of symptoms. We used principal component analysis with varimax rotation to identify domains related to QoL. The median age of interviewees was 36 years. Most (85%) reported their general health status as very good or good before the dengue episode. Although ambulatory patients were mainly classified as having dengue fever, 44.8% of hospitalized patients had dengue hemorrhagic fever or intermediate dengue. Principal component analysis identified five principal components related to cognition, sleep and energy, mobility, self-care, pain, and discomfort, which explained 73% of the variability of the data matrix. Hospitalized patients had significantly lower mean scores for dimensions cognition, self-care, and pain than ambulatory patients. This investigation documented the generally poor QoL during a dengue episode caused by the large number of domains affected and significant differences between health care settings.

  2. Value of routine dengue diagnosis in endemic countries

    PubMed Central

    Ayukekbong, James Ayukepi; Oyero, Olufunmilayo G; Nnukwu, Samuel Ekpesu; Mesumbe, Henry Nzike; Fobisong, Cajetang Nkong

    2017-01-01

    Dengue is one of the most common arthropod-borne viral diseases in humans and it is a leading cause of illness and death in the tropical and subtropical regions of the world. It is thought to account for 400 million cases annually among approximately 3.97 billion people at risk of infection in 128 endemic countries. Despite the global prevalence of the disease, the availability of a vaccine is limited in most countries in the endemic areas. Most endemic countries in South America, South East Asia and Africa serve as attractive touristic sites for people from non-endemic countries who become infected and export the virus to dengue-free regions. Dengue fever typically resembles malaria and in endemic countries most cases of dengue are treated as presumptive malaria. Consequently, routine dengue diagnosis among persons with fever will offer early treatment and reduce the burden of the disease. Also, routine testing among travellers from endemic countries will reduce importation and prevent the geographical expansion of dengue. In this essay, we seek to highlight the usefulness of routine dengue testing in endemic countries. PMID:28239567

  3. Quality of Life among Adults with Confirmed Dengue in Brazil

    PubMed Central

    Martelli, Celina Maria Turchi; Nascimento, Nazareth Elias; Suaya, Jose A.; Siqueira, Joao Bosco; Souza, Wayner Vieira; Turchi, Marilia Dalva; Guilarde, Adriana Oliveira; Peres, Joao Borges; Shepard, Donald S.

    2011-01-01

    The main objective of this study was to measure the quality of life (QoL) during a dengue episode. We conducted a facility-based survey in central Brazil in 2005 and recruited 372 laboratory-confirmed dengue patients greater than 12 years of age in hospital and ambulatory settings. We administered the World Health Organization QoL instrument approximately 15 days after the onset of symptoms. We used principal component analysis with varimax rotation to identify domains related to QoL. The median age of interviewees was 36 years. Most (85%) reported their general health status as very good or good before the dengue episode. Although ambulatory patients were mainly classified as having dengue fever, 44.8% of hospitalized patients had dengue hemorrhagic fever or intermediate dengue. Principal component analysis identified five principal components related to cognition, sleep and energy, mobility, self-care, pain, and discomfort, which explained 73% of the variability of the data matrix. Hospitalized patients had significantly lower mean scores for dimensions cognition, self-care, and pain than ambulatory patients. This investigation documented the generally poor QoL during a dengue episode caused by the large number of domains affected and significant differences between health care settings. PMID:21976580

  4. Pathogenesis of Dengue: Dawn of a New Era

    PubMed Central

    Halstead, Scott B.

    2015-01-01

    Dengue virus (DENV) infections of humans were long thought to be self-limited and of low mortality. Beginning in the 1950s, at the time when four different DENVs were discovered, a lethal variant of dengue emerged. Dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) initially observed in Southeast Asia now has spread throughout the world. Two risk factors for DHF/DSS are well-established: severe disease occurs during a second heterotypic DENV infection or during a first DENV infection in infants born to dengue-immune mothers. A large number of hypotheses have been proposed to explain severe dengue disease. As discussed, few of them attempt to explain why severe disease occurs under the two different immunological settings. New experimental evidence has demonstrated that DENV non-structural protein 1 (NS1) is toll-receptor 4 agonist that stimulates primary human myeloid cells to produce the same cytokines observed during the course of severe dengue disease. In addition, NS1 directly damages endothelial cells. These observations have been repeated and extended to an in vivo mouse model. The well-established phenomenon, antibody-dependent enhancement of DENV infection in Fc-receptor-bearing cells, should similarly enhance the production of DENV NS1 in humans, providing a unitary mechanism for severe disease in both immunological settings PMID:26918141

  5. AfroColombian ethnicity, a paradoxical protective factor against Dengue

    PubMed Central

    Alzate, Alberto; Martínez Romero, Héctor Jairo; Concha-Eastman, Alberto Ignacio

    2016-01-01

    Introduction: Dengue is a priority public health problem. During epidemics in Cuba and Haiti, ethnic African descendant population had lower risk of dengue, and the ethnic factor was proposed as a protective one. Objective: To determine the relation between the Dengue's cumulative incidence and the Afro-Colombian proportion in communities of Cali, during the epidemic of 2013. Methods: This study was conducted in Cali, Colombia. The design was ecological, using information from the National Census 2005 projected to 2013, from the National Administrative Department of Statistics (DANE), and the National Epidemiological Surveillance System. It was obtained the Pearson´s correlation coefficient between cumulative incidence and the proportion of Afro-Colombian population by communities. Additionally, the cumulative incidences of dengue were evaluated in two zones with different proportion of Afro-Colombian population. The association was also evaluated for aggregation bias, confounding by social variables, and interaction by area of ​​residence. Results: Dengue´s cumulative incidence was significantly lower for Afro-Colombians regardless of the proportion of Afro-Colombian population in the area of residence. The relative risk of dengue between non-Afro-Colombians and Afro-Colombians was 9.4 (95% CI=8.4-10.6) in zones with high proportion of Afro-Colombian population, while the relative risk of dengue was 4.0 (95% CI :3.6 - 4.4) in the zone with lower proportion of Afro-Colombian population. There was no evidence of aggregation bias or confounding in the association by social variables. Conclusions: The Afro-Colombian population had a significantly lower risk of getting dengue and its complications, compared with the non-Afro-Colombian population. The non-Afro-Colombian populations living in areas with a high proportion of Afro-Colombians increase their risk of dengue more than double, suggesting an asymptomatic viremic environment. PMID:27821892

  6. Dengue hemorrhagic fever--U.S.-Mexico border, 2005.

    PubMed

    2007-08-10

    Dengue fever is a mosquito-transmitted disease caused by any of four closely related virus serotypes (DEN-1, DEN-2, DEN-3, and DEN-4) of the genus Flavivirus. Infection with one of these serotypes provides lifelong immunity to the infecting serotype only. Therefore, persons can acquire a second dengue infection from a different serotype, and second infections place them at greater risk for dengue hemorrhagic fever (DHF), the more severe form of the disease. DHF is characterized by bleeding manifestations, thrombocytopenia, and increased vascular permeability that can lead to life-threatening shock. In south Texas, near the border with Mexico, sporadic, locally acquired outbreaks of dengue fever have been reported previously; however, on the Texas side of the border, these outbreaks have not included recognized cases of locally acquired DHF in persons native to the area. In July 2005, a case of DHF was reported in a resident of Brownsville, Texas. In August 2005, health authorities in the neighboring state of Tamaulipas, Mexico, reported an ongoing dengue outbreak with 1,251 cases of dengue fever, including 223 cases (17.8%) of DHF. To characterize this dengue outbreak, the Texas Department of State Health Services (TDSHS), Mexican health authorities, and CDC conducted a clinical and epidemiologic investigation. This report summarizes the results of that investigation, which determined that the percentage of DHF cases associated with dengue fever outbreaks at the Texas-Tamaulipas border has increased. Health-care providers along the U.S. border with Mexico should be vigilant for DHF and familiar with its diagnosis and management to reduce the number of severe illnesses and deaths associated with outbreaks of dengue fever.

  7. Clinical course of dengue in patients with thalassaemia.

    PubMed

    Natesirinilkul, Rungrote; Tantiworawit, Adisak; Charoenkwan, Pimlak

    2013-02-01

    Dengue and thalassaemia are prevalent in tropical regions. Thalassaemia patients with dengue present with atypical clinical manifestations and may experience more severe disease and complications. To investigate the clinical manifestations and outcome in thalassaemia patients with dengue. Medical records of thalassaemia patients aged from birth to 18 years with serologically-confirmed dengue who were admitted to Chiang Mai University Hospital, Thailand from January 2005 to December 2010 were reviewed retrospectively. Clinical presentation, laboratory results and outcome were analysed. Twenty patients were included and their mean (SD) age was 13·6 (3·1) years. Patients were as follows: haemoglobin H (HbH)/Hb Constant Spring disease 7, HbH disease 3, HbH disease/HbE trait one, beta-thalassaemia/HbE disease 7, beta-thalassaemia/HbS disease one and unspecified thalassaemia one. Four patients had primary and the others secondary dengue. Five patients (25%) had severe dengue, three with severe liver involvement, one with a massive upper gastro-intestinal haemorrhage and one with acute interstitial nephritis, raised creatinine and seizures. Nineteen patients required red cells transfusions. All made a full recovery. Almost all patients presented with haemoglobin lower than baseline. While mean (SD) haemoglobin at baseline was 8·2 (1·6) g/dl, mean (SD) haemoglobin on admission was 6·4 (1·6) g/dl. Median maximum AST and ALT levels were 359 (range 42-5344) and 81 (12-1846) units/L, respectively. Thalassaemia patients with dengue present with anaemia rather than haemoconcentration. Most patients have markedly increased AST levels in relation to ALT, and severe dengue, especially severe liver involvement, is common. In patients with thalassaemia, awareness of the atypical manifestations should aid early recognition of dengue.

  8. Forecast of Dengue Incidence Using Temperature and Rainfall

    PubMed Central

    Hii, Yien Ling; Zhu, Huaiping; Ng, Nawi; Ng, Lee Ching; Rocklöv, Joacim

    2012-01-01

    Introduction An accurate early warning system to predict impending epidemics enhances the effectiveness of preventive measures against dengue fever. The aim of this study was to develop and validate a forecasting model that could predict dengue cases and provide timely early warning in Singapore. Methodology and Principal Findings We developed a time series Poisson multivariate regression model using weekly mean temperature and cumulative rainfall over the period 2000–2010. Weather data were modeled using piecewise linear spline functions. We analyzed various lag times between dengue and weather variables to identify the optimal dengue forecasting period. Autoregression, seasonality and trend were considered in the model. We validated the model by forecasting dengue cases for week 1 of 2011 up to week 16 of 2012 using weather data alone. Model selection and validation were based on Akaike's Information Criterion, standardized Root Mean Square Error, and residuals diagnoses. A Receiver Operating Characteristics curve was used to analyze the sensitivity of the forecast of epidemics. The optimal period for dengue forecast was 16 weeks. Our model forecasted correctly with errors of 0.3 and 0.32 of the standard deviation of reported cases during the model training and validation periods, respectively. It was sensitive enough to distinguish between outbreak and non-outbreak to a 96% (CI = 93–98%) in 2004–2010 and 98% (CI = 95%–100%) in 2011. The model predicted the outbreak in 2011 accurately with less than 3% possibility of false alarm. Significance We have developed a weather-based dengue forecasting model that allows warning 16 weeks in advance of dengue epidemics with high sensitivity and specificity. We demonstrate that models using temperature and rainfall could be simple, precise, and low cost tools for dengue forecasting which could be used to enhance decision making on the timing, scale of vector control operations, and utilization of limited

  9. Is dengue a disease of poverty? A systematic review.

    PubMed

    Mulligan, Kate; Dixon, Jenna; Sinn, Chi-Ling Joanna; Elliott, Susan J

    2015-02-01

    Policy prescriptions for combating dengue fever tend to focus on addressing environmental and social conditions of poverty. However, while poverty has long been considered a determinant of dengue, the research evidence for such a relationship is not well established. Results of a systematic review of the research literature designed to identify and assess the current state of the empirical evidence for the dengue-poverty link reveal a mixed story. Of 260 peer-reviewed articles referencing dengue-poverty relationships, only 12 English-language studies empirically assessed these relationships. Our analysis covering various social and economic conditions of poverty showed no clear associations with dengue rates. While nine of the 12 studies demonstrated some positive associations between measures of dengue and poverty (measured inconsistently through income, education, structural housing condition, overcrowding, and socioeconomic status), nine also presented null results and five with negative results. Of the five studies relating to access to water and sanitation, four reported null associations. Income and physical housing conditions were more consistently correlated with dengue outcomes than other poverty indicators. The small size of this sample, and the heterogeneity of measures and scales used to capture conditions of poverty, make it difficult to assess the strength and consistency of associations between various poverty indicators and dengue outcomes. At present, the global body of eligible English-language peer-reviewed literature investigating dengue-poverty relationships is too small to support a definitive relationship. We conclude that more research, particularly using standardized measures of both outcomes and indicators, is needed to support evidence-informed policies and approaches.

  10. Challenges for the formulation of a universal vaccine against dengue.

    PubMed

    Chokephaibulkit, Kulkanya; Perng, Guey Chuen

    2013-05-01

    Dengue is rapidly becoming a disease of an escalating global public health concern. The disease is a vector-borne disease, transmitted by the bite of an Aedes spp. mosquito. Dynamic clinical manifestations, ranging from asymptomatic, flu-like febrile illness, dengue fever (DF) to dengue hemorrhagic fever (DHF) with or without dengue shock syndrome (DSS), make the disease one of the most challenging to diagnose and treat. DF is a self-limited illness, while DHF/DSS, characterized by plasma leakage resulting from an increased vascular permeability, can have severe consequences, including death. The pathogenesis of dengue virus infection remains poorly understood, mainly due to the lack of a suitable animal model that can recapitulate the cardinal features of human dengue diseases. Currently, there is no specific treatment or antiviral therapy available for dengue virus infection and supportive care with vigilant monitoring is the principle course of treatment. Since vector control programs have been largely unsuccessful in preventing outbreaks, vaccination seems to be the most viable option for prevention. There are four dengue viral serotypes and each one of them is capable of causing severe dengue. Although immunity induced by infection by one serotype is effective in protection against the homologous viral serotype, it only has a transient protective effect against infection with the other three serotypes. The meager cross protective immunity generated wanes over time and may even induce a harmful effect at the time of subsequent secondary infection. Thus, it is imperative to have a vaccine that can elicit equal and long-lasting immunity to all four serotypes simultaneously. Numerous tetravalent vaccines are currently either in the pipeline for clinical trials or under development. For those frontrunner tetravalent vaccines in clinical trials, despite good safety and immunogenicity profiles registered, issues such as imbalanced immune responses between serotypes

  11. Licensed Dengue Vaccine: Public Health Conundrum and Scientific Challenge

    PubMed Central

    Halstead, Scott B.

    2016-01-01

    A tetravalent live attenuated vaccine composed of chimeras of yellow fever 17D and the four dengue viruses (chimeric yellow fever dengue [CYD]) manufactured by Sanofi Pasteur has completed phase III clinical testing in over 35,000 children 2–16 years of age. The vaccine was recently licensed in four countries. During the first 2 years of observation, CYD vaccine efficacy ranged between 30% and 79% in 10 different countries with an overall efficacy of 56.8%. During year 3, there was an overall efficacy against hospitalization of 16.7%, but a relative risk of hospitalization of 1.6 among children younger than 9 years and 4.95 in children 5 years of age and younger. Vaccination of seronegative children resulted in universal broad dengue neutralizing antibody responses, but poor protection against breakthrough dengue cases. Unless proven otherwise, such breakthrough cases in vaccinated subjects should be regarded as vaccine antibody-enhanced (ADE). The provenance of these cases can be studied serologically using original antigenic sin immune responses in convalescent sera. In conventional dengue vaccine efficacy clinical trials, persons vaccinated as seronegatives may be hospitalized with breakthrough ADE infections, whereas in the placebo group, dengue infection of monotypic immunes results in hospitalization. Vaccine efficacy trial design must identify dengue disease etiology by separately measuring efficacy in seronegatives and seropositives. The reason(s) why CYD vaccine failed to raise protective dengue virus immunity are unknown. To achieve a safe and protective dengue vaccine, careful studies of monotypic CYD vaccines in humans should precede field trials of tetravalent formulations. PMID:27352870

  12. Dengue infections in non-immune travellers to Thailand.

    PubMed

    Massad, E; Rocklov, J; Wilder-Smith, A

    2013-02-01

    Dengue is the most frequent arboviral disease and is expanding geographically. Dengue is also increasingly being reported in travellers, in particular in travellers to Thailand. However, data to quantify the risk of travellers acquiring dengue when travelling to Thailand are lacking. Using mathematical modelling, we set out to estimate the risk of non-immune persons acquiring dengue when travelling to Thailand. The model is deterministic with stochastic parameters and assumes a Poisson distribution for the mosquitoes' biting rate and a Gamma distribution for the probability of acquiring dengue from an infected mosquito. From the force of infection we calculated the risk of dengue acquisition for travellers to Thailand arriving in a typical year (averaged over a 17-year period) in the high season of transmission. A traveller arriving in the high season of transmission and remaining for 7 days has a risk of acquiring dengue of 0·2% (95% CI 0·16-0·23), whereas the risk for travel of 15 and 30 days' duration is 0·46% (95% CI 0·41-0·50) and 0·81% (95% CI 0·76-0·87), respectively. Our data highlight that the risk of non-immune travellers acquiring dengue in Thailand is substantial. The incidence of 0·81% after a 1-month stay is similar to that reported in prospective seroconversion studies in Israeli travellers to Thailand, highlighting that our models are consistent with actual data. Risk estimates based on mathematical modelling offer more detailed information depending on various travel scenarios, and will help the travel medicine provider give better evidence-based advice for travellers to dengue-endemic countries.

  13. Attack rates of dengue fever in Swedish travellers.

    PubMed

    Rocklöv, Joacim; Lohr, Wolfgang; Hjertqvist, Marika; Wilder-Smith, Annelies

    2014-06-01

    Dengue is endemic in many countries visited by Swedish travellers. We aimed to determine the attack rate of dengue in Swedish travellers and analyse the trends over time and the geographical variation. We obtained the following data from the Swedish Institute for Communicable Disease Control for the y 1995-2010: number of Swedish residents with confirmed dengue, the country and year of infection. We also obtained registers on the Swedish annual air traveller arrivals to dengue endemic areas from the United Nations World Tourist Organization for the time period. We estimated attack rates with 95% confidence intervals (CI). In total, 925 Swedish travellers with confirmed dengue were reported. We found an increasing trend over time for most destinations. The majority of the dengue cases were acquired in Thailand (492 out of 925 travellers; 53%), with an attack rate of 13.6 (95% CI 12.7, 14.4) per 100,000 travellers. However, the 2 highest attack rates per 100,000 travellers were found for Sri Lanka (45.3, 95% CI 34.3, 56.4) and Bangladesh (42.6, 95% CI 23.8, 61.5). Information on attack rates in travellers is more helpful in guiding travel medicine practitioners than reports of absolute numbers, as the latter reflect travel preferences rather than the true risk. Although the majority of dengue infections in Swedish travellers were acquired in Thailand, the attack rates for dengue in travellers to Sri Lanka and Bangladesh were much higher. These data aid in refining information on the risk of dengue in travellers.

  14. Expanded dengue syndrome: subacute thyroiditis and intracerebral hemorrhage

    PubMed Central

    2012-01-01

    Background Although most symptomatic dengue infections follow an uncomplicated course, complications and unusual manifestations are increasingly being reported due to rising disease burden. Expanded dengue syndrome is a new entity added into World Health Organization (WHO) classification system to incorporate this wide spectrum of unusual manifestations. We report a case of expanded dengue syndrome with subacute thyroiditis and intracerebral hemorrhage. This is the first case report of thyroiditis in dengue infection. Case presentation A 20 years old man presented with fever, myalgias, arthralgias, retro-orbital pain, vomiting and gum bleeding during a large dengue outbreak in Lahore, Pakistan. On 7th day of illness patient became afebrile, but he developed severe headaches, unconsciousness followed by altered behavior. On 9th day of illness patient developed painful neck swelling accompanied by fever, tremors, palpitations, hoarseness of voice and odynophagia. Examination revealed acutely swollen, tender thyroid gland along with features of hyperthyroidism. Laboratory evaluation revealed stable hematocrit, thrombocytopenia and leukopenia. Patient had seroconverted for anti-dengue IgM antibodies on the 10th day of illness. A non-contrast Computed Tomogram (CT) of the brain showed right frontal lobe hematoma. Thyroid profile showed increased free T3 and T4 and low TSH. Technetium thyroid scan showed reduced tracer uptake. He was diagnosed as having subacute thyroiditis and treated with oral prednisolone and propranolol. Follow up CT brain showed resolving hematoma. Patient’s recovery was uneventful. Conclusion Subacute thyroiditis may develop during the course of dengue fever and should be included as a manifestation of expanded dengue syndrome. It should be suspected in patients with dengue fever who develop painful thyroid swelling and clinical features of hyperthyroidism. PMID:23033818

  15. AfroColombian ethnicity, a paradoxical protective factor against Dengue.

    PubMed

    Rojas Palacios, Jorge Humberto; Alzate, Alberto; Martínez Romero, Héctor Jairo; Concha-Eastman, Alberto Ignacio

    2016-09-30

    Dengue is a priority public health problem. During epidemics in Cuba and Haiti, ethnic African descendant population had lower risk of dengue, and the ethnic factor was proposed as a protective one. To determine the relation between the Dengue's cumulative incidence and the Afro-Colombian proportion in communities of Cali, during the epidemic of 2013. This study was conducted in Cali, Colombia. The design was ecological, using information from the National Census 2005 projected to 2013, from the National Administrative Department of Statistics (DANE), and the National Epidemiological Surveillance System. It was obtained the Pearson´s correlation coefficient between cumulative incidence and the proportion of Afro-Colombian population by communities. Additionally, the cumulative incidences of dengue were evaluated in two zones with different proportion of Afro-Colombian population. The association was also evaluated for aggregation bias, confounding by social variables, and interaction by area of ​​residence. Dengue´s cumulative incidence was significantly lower for Afro-Colombians regardless of the proportion of Afro-Colombian population in the area of residence. The relative risk of dengue between non-Afro-Colombians and Afro-Colombians was 9.4 (95% CI=8.4-10.6) in zones with high proportion of Afro-Colombian population, while the relative risk of dengue was 4.0 (95% CI :3.6 - 4.4) in the zone with lower proportion of Afro-Colombian population. There was no evidence of aggregation bias or confounding in the association by social variables. The Afro-Colombian population had a significantly lower risk of getting dengue and its complications, compared with the non-Afro-Colombian population. The non-Afro-Colombian populations living in areas with a high proportion of Afro-Colombians increase their risk of dengue more than double, suggesting an asymptomatic viremic environment.

  16. Dengue virus-like particles: construction and application.

    PubMed

    Shang, Weilong; Liu, Jie; Yang, Jie; Hu, Zhen; Rao, Xiancai

    2012-04-01

    Virus-like particles (VLPs) are shell-like viruses that lack virus-specific genetic materials. Many viral-structured proteins can assemble into VLPs, which mimic the overall structure of virus particles and can elicit strong immune responses in a host. Dengue viruses (DENVs), from the genus Flavivirus, are transmitted to humans through the bites of an infected Aedes mosquito. DENVs cause several diseases that prevailed mainly in tropical and subtropical areas. However, effective treatment measures and preventive strategies for dengue diseases are still lacking. The present minireview summarized the assembly and maturation of DENVs, the strategies and effective factors for dengue VLP construction, and the application of DENV VLPs.

  17. Dengue vaccine: hypotheses to understand CYD-TDV-induced protection.

    PubMed

    Guy, Bruno; Jackson, Nicholas

    2016-01-01

    Dengue virus (DENV) is a human pathogen with a large impact on public health. Although no vaccine against DENV is currently licensed, a recombinant vaccine - chimeric yellow fever virus-DENV tetravalent dengue vaccine (CYD-TDV) - has shown efficacy against symptomatic dengue disease in two recent Phase III clinical trials. Safety observations were also recently reported for these trials. In this Opinion article, we review the data from recent vaccine clinical trials and discuss the putative mechanisms behind the observed efficacy of the vaccine against different forms of the disease, focusing on the interactions between the infecting virus, pre-existing host immunity and vaccine-induced immune responses.

  18. Dengue Fever Presenting Atypically with Viral Conjunctivitis and Subacute Thyroiditis.

    PubMed

    Sheraz, Faizan; Tahir, Hassan; Saqi, Jannavi; Daruwalla, Vistasp

    2016-06-01

    The majority of dengue viral infections are asymptomatic, though symptoms may range from self-limiting febrile illness to life threatening hemorrhagic manifestations. As the burden of disease is dramatically rising in recent years, more patients with atypical presentations and rare complications are increasingly reported. Dengue virus may rarely involve different organ systems including CNS, liver, and heart. However, involvement of eye and thyroid is extremely rare. We present a case of 32-year old patient who presented with conjunctivitis and subacute thyroiditis and was found to have dengue viral infection as the cause of these conditions.

  19. Recent advances in dengue pathogenesis and clinical management.

    PubMed

    Simmons, Cameron P; McPherson, Kirsty; Van Vinh Chau, Nguyen; Hoai Tam, D T; Young, Paul; Mackenzie, Jason; Wills, Bridget

    2015-12-10

    This review describes and commentates on recent advances in the understanding of dengue pathogenesis and immunity, plus clinical research on vaccines and therapeutics. We expand specifically on the role of the dermis in dengue virus infection, the contribution of cellular and humoral immune responses to pathogenesis and immunity, NS1 and mechanisms of virus immune evasion. Additionally we review a series of therapeutic intervention trials for dengue, as well as recent clinical research aimed at improving clinical diagnosis, risk prediction and disease classification. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. Animal models for studying dengue pathogenesis and therapy.

    PubMed

    Chan, Kitti Wing Ki; Watanabe, Satoru; Kavishna, Ranmali; Alonso, Sylvie; Vasudevan, Subhash G

    2015-11-01

    Development of a suitable animal model for dengue virus disease is critical for understanding pathogenesis and for preclinical testing of antiviral drugs and vaccines. Many laboratory animal models of dengue virus infection have been investigated, but the challenges of recapitulating the complete disease still remain. In this review, we provide a comprehensive coverage of existing models, from man to mouse, with a specific focus on recent advances in mouse models for addressing the mechanistic aspects of severe dengue in humans. This article forms part of a symposium in Antiviral Research on flavivirus drug discovery. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Dengue infection associated hemophagocytic syndrome: Therapeutic interventions and outcome.

    PubMed

    Wan Jamaludin, Wan Fariza; Periyasamy, Petrick; Wan Mat, Wan Rahiza; Abdul Wahid, S Fadilah

    2015-08-01

    Infection associated hemophagocytic syndrome is increasingly recognized as a potentially fatal complication of dengue fever. It should be suspected with prolonged fever beyond seven days associated with hepatosplenomegaly, hyperferritinemia, worsening cytopenias and development of multiorgan dysfunction. Surge of similar pro-inflammatory cytokines observed in dengue associated hemophagocytic syndrome and multiorgan dysfunction may indicate they are part of related inflammatory spectrum. A proportion of patients recovered with supportive therapy, however most required interventions with corticosteroids, intravenous immunoglobulin or chemotherapy. We report three cases of dengue associated IAHS with good outcome following early recognition and treatment with dexamethasone and intravenous immunoglobulin. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Fundus Findings in Dengue Fever: A Case Report.

    PubMed

    Şahan, Berna; Tatlıpınar, Sinan; Marangoz, Deniz; Çiftçi, Ferda

    2015-10-01

    Dengue fever is a flavivirus infection transmitted through infected mosquitoes, and is endemic in Southeast Asia, Central and South America, the Pacific, Africa and the Eastern Mediterranean region. A 41-year-old male patient had visual impairment after travelling to Thailand, which is one of the endemic areas. Cotton wool spots were observed on fundus examination. Fundus fluorescein angiography showed minimal vascular leakage from areas near the cotton wool spots and dot hemorrhages in the macula. Dengue fever should be considered in patients with visual complaints who traveled to endemic areas of dengue fever.

  3. Dengue Fever Presenting as Purtscher-like Retinopathy.

    PubMed

    Lima, Luiz H; Vianello, Silvana; Pimentel, Sérgio; Costa de Andrade, Gabriel; Zett, Claudio; Muller, Léo; Farah, Michel E; Belfort, Rubens

    2017-03-21

    To report the fundus manifestations and spectral-domain optical coherence tomographic (SD-OCT) features of dengue fever presenting as Purtscher-like retinopathy. Retrospective review of two cases of dengue fever. Color fundus photograph revealed the presence of cotton-wool spots in a Purtscher-like configuration in the posterior pole of all study eyes. SD-OCT demonstrated increased reflectivity signal in the inner retinal layers, and after a variable follow-up period, there was complete disappearance of cotton-wool spots and persistence of the hyperreflectivity signal. We report two unique cases of dengue fever associated with retinal lesions in a configuration of Purtscher-like retinopathy.

  4. Clinical Profile of Atypical Manifestations of Dengue Fever.

    PubMed

    Pothapregada, Sriram; Kamalakannan, Banupriya; Thulasingam, Mahalakshmy

    2016-06-01

    To study the clinical profile and outcome of the atypical manifestations of dengue fever in children. All children (0-12 y of age) diagnosed and confirmed as dengue fever at a tertiary care hospital at Puducherry, between the 1st of August 2012 and January 31st 2015 were reviewed retrospectively from hospital case records as per the revised World Health Organization (WHO) guidelines 2011 for dengue fever. The diagnosis was confirmed by NS1 antigen-based ELISA test or dengue serology for IgM and IgG antibodies and the data was analyzed using SPSS 16.0 statistical software. Out of 254 children admitted with dengue fever, non-severe dengue and severe dengue were seen in 62.6 % and 37.4 % respectively. Atypical manifestations were seen in 106 cases (41.7 %). Mean age of presentation was 6.9(3.3) y. M: F ratio was 1.2:1. The common manifestations of severe dengue infection were shock (37.4 %), bleeding (20.1 %) and multi-organ dysfunction (2.4 %). The most common atypical manifestations of dengue fever were lymphadenopathy (41.7 %), splenomegaly (21.2 %), biphasic fever (18.1 %), hepatitis (11.4 %), febrile diarrhea (6.3 %), refractory shock (2.4 %) and impaired consciousness (1.9 %). The other atypical manifestations present were portal hypertension, acalculous cholecystitis, appendicitis, acute respiratory distress syndrome (ARDS), myocarditis, pericardial effusion, paroxysmal supraventricular tachycardia (PSVT), myositis, acute kidney injury (AKI), hemophagocytic syndrome and disseminated intravascular coagulopathy (DIC). Platelet count did not always correlate well with the severity of bleeding. There were six deaths (2.4 %) and out of them four presented with impaired consciousness (66.6 %). The common causes for poor outcome were multiorgan failure, encephalopathy and refractory shock. The atypical manifestations of dengue fever are no more a rare entity. Clinicians should have a high index of suspicion and vigilance for atypical manifestations of

  5. Structure and Functional Studies on Dengue-2 Virus Genome

    DTIC Science & Technology

    1986-03-01

    AD STRUCTURE AND FUNCTIONAL STUDIES ON DENGUE -2 VIRUS GENOME FINAL Report Lfl C’) Radha Krishnan Padmanabhan, Ph.D. 0) March 1, 1986 Supported by U.S...and Functional Studies on Dengue -2 Virus Genome 12. PERSONAL AUTHOR(S) Radha Krishnan Padmanabhan 13a. TYPE OF REPORT 13b. TIME COVERED 14. DATE OF...3’-end of Dengue RNA in order to facilitate cDNA synthesis by oligo d(T) priming as proposed in the original research project. 2. We also showed that

  6. Structure and Functional Studies on Dengue-2 Virus Genome

    DTIC Science & Technology

    1986-03-01

    AD_ _ _ Lfl oSTRUCTURE AND FUNCTIONAL STUDIES ON DENGUE -2 VIRUS GENOME 0Annual Report Radha Krishnan Padmanabhan, Ph.D. March 1, 1986 Supported by...Studies on Dengue -2 Virus Genome 12 PERSONAL AUTHOR(S) Radha Krishnan Padmanabhan 13a TYPE OF REPORT 1 3b TIME COVERED 14 DATE OF REPORT (Year, Month, Day...analysis of these clones totalling 06 01 14,586 nucleotides: Deduced amino acid sequences of dengue virI 19 ABSTRACT (Continue on reverse of

  7. Genetically engineered resistance to dengue-2 virus transmission in mosquitoes.

    PubMed

    Olson, K E; Higgs, S; Gaines, P J; Powers, A M; Davis, B S; Kamrud, K I; Carlson, J O; Blair, C D; Beaty, B J

    1996-05-10

    The control of arthropod-borne virus diseases such as dengue may ultimately require the genetic manipulation of mosquito vectors to disrupt virus transmission to human populations. To reduce the ability of mosquitoes to transmit dengue viruses, a recombinant Sindbis virus was used to transduce female Aedes aegypti with a 567-base antisense RNA targeted to the premembrane coding region of dengue type 2 (DEN-2) virus. The transduced mosquitoes were unable to support replication of DEN-2 virus in their salivary glands and therefore were not able to transmit the virus.

  8. Dengue Surveillance in Veterans Affairs Healthcare Facilities, 2007–2010

    PubMed Central

    Schirmer, Patricia L.; Lucero-Obusan, Cynthia A.; Benoit, Stephen R.; Santiago, Luis M.; Stanek, Danielle; Dey, Achintya; Martinez, Mirsonia; Oda, Gina; Holodniy, Mark

    2013-01-01

    Background Although dengue is endemic in Puerto Rico (PR), 2007 and 2010 were recognized as epidemic years. In the continental United States (US), outside of the Texas-Mexico border, there had not been a dengue outbreak since 1946 until dengue re-emerged in Key West, Florida (FL), in 2009–2010. The objective of this study was to use electronic and manual surveillance systems to identify dengue cases in Veterans Affairs (VA) healthcare facilities and then to clinically compare dengue cases in Veterans presenting for care in PR and in FL. Methodology Outpatient encounters from 1/2007–12/2010 and inpatient admissions (only available from 10/2009–12/2010) with dengue diagnostic codes at all VA facilities were identified using VA's Electronic Surveillance System for Early Notification of Community-based Epidemics (ESSENCE). Additional case sources included VA data from Centers for Disease Control and Prevention BioSense and VA infection preventionists. Case reviews were performed. Categorical data was compared using Mantel-Haenszel or Fisher Exact tests and continuous variables using t-tests. Dengue case residence was mapped. Findings Two hundred eighty-eight and 21 PR and FL dengue cases respectively were identified. Of 21 FL cases, 12 were exposed in Key West and 9 were imported. During epidemic years, FL cases had significantly increased dengue testing and intensive care admissions, but lower hospitalization rates and headache or eye pain symptoms compared to PR cases. There were no significant differences in clinical symptoms, laboratory abnormalities or outcomes between epidemic and non-epidemic year cases in FL and PR. Confirmed/probable cases were significantly more likely to be hospitalized and have thrombocytopenia or leukopenia compared to suspected cases. Conclusions Dengue re-introduction in the continental US warrants increased dengue surveillance and education in VA. Throughout VA, under-testing of suspected cases highlights the need to emphasize use

  9. Economic Impact of Dengue: Multicenter Study across Four Brazilian Regions

    PubMed Central

    Martelli, Celina Maria Turchi; Siqueira, Joao Bosco; Parente, Mirian Perpetua Palha Dias; Zara, Ana Laura de Sene Amancio; Oliveira, Consuelo Silva; Braga, Cynthia; Pimenta, Fabiano Geraldo; Cortes, Fanny; Lopez, Juan Guillermo; Bahia, Luciana Ribeiro; Mendes, Marcia Costa Ooteman; da Rosa, Michelle Quarti Machado; de Siqueira Filha, Noemia Teixeira; Constenla, Dagna; de Souza, Wayner Vieira

    2015-01-01

    Background Dengue is an increasing public health concern in Brazil. There is a need for an updated evaluation of the economic impact of dengue within the country. We undertook this multicenter study to evaluate the economic burden of dengue in Brazil. Methods We estimated the economic burden of dengue in Brazil for the years 2009 to 2013 and for the epidemic season of August 2012- September 2013. We conducted a multicenter cohort study across four endemic regions: Midwest, Goiania; Southeast, Belo Horizonte and Rio de Janeiro; Northeast: Teresina and Recife; and the North, Belem. Ambulatory or hospitalized cases with suspected or laboratory-confirmed dengue treated in both the private and public sectors were recruited. Interviews were scheduled for the convalescent period to ascertain characteristics of the dengue episode, date of first symptoms/signs and recovery, use of medical services, work/school absence, household spending (out-of-pocket expense) and income lost using a questionnaire developed for a previous cost study. We also extracted data from the patients’ medical records for hospitalized cases. Overall costs per case and cumulative costs were calculated from the public payer and societal perspectives. National cost estimations took into account cases reported in the official notification system (SINAN) with adjustment for underreporting of cases. We applied a probabilistic sensitivity analysis using Monte Carlo simulations with 90% certainty levels (CL). Results We screened 2,223 cases, of which 2,035 (91.5%) symptomatic dengue cases were included in our study. The estimated cost for dengue for the epidemic season (2012–2013) in the societal perspective was US$ 468 million (90% CL: 349–590) or US$ 1,212 million (90% CL: 904–1,526) after adjusting for under-reporting. Considering the time series of dengue (2009–2013) the estimated cost of dengue varied from US$ 371 million (2009) to US$ 1,228 million (2013). Conclusions The economic burden

  10. Isolation and characterization of two phenotypically distinct dengue type-2 virus isolates from the same dengue hemorrhagic Fever patient.

    PubMed

    Kinoshita, Hitomi; Mathenge, Edward Gitau Matumbi; Hung, Nguyen Thanh; Huong, Vu Thi Que; Kumatori, Atsushi; Yu, Fuxun; Parquet, Maria Carmen; Inoue, Shingo; Matias, Ronald Roll; Natividad, Filipinas Florendo; Morita, Kouichi; Hasebe, Futoshi

    2009-09-01

    Dengue is the one of the most prevalent arthropod-borne viral diseases. Dengue virus circulates between humans and mosquitoes, and causes a wide range of disease in humans. To elucidate the link between the cell tropism of dengue virus and its pathogenesis, peripheral blood cells of infected patients were analyzed by flow cytometry. The dengue virus antigen was detected in peripheral CD19+ cells (B cells) in one dengue hemorrhagic fever patient. Two dengue type-2 virus isolates were recovered from this patient using mosquito cell line C6/36 and human hematopoietic cell line K562, and designated VNHCM18-C/02 and VNHCM18-K/02, respectively. VNHCM18-K/02 exhibited strong binding ability and high infectivity to a B-lymphocyte cell line (RPMI8226) but showed poor growth in C6/36 cells, while VNHCM18-C/02 more efficiently and dominantly grew in C6/36 cells but did not efficiently bind to nor infect the B-cell line. Three amino acid differences were detected; one in an envelope protein (E-62) and two in nonstructural proteins. The distinct cell-binding to RPMI8226 was attributed to the difference between the two isolates in envelope protein E-62. Thus, we isolated two dengue type-2 virus variants with different cell-tropisms from the same patient, suggesting possible co-circulation in the patient.

  11. Arterial hypertension and skin allergy are risk factors for progression from dengue to dengue hemorrhagic fever: a case control study.

    PubMed

    Teixeira, Maria Glória; Paixão, Enny S; Costa, Maria da Conceição N; Cunha, Rivaldo V; Pamplona, Luciano; Dias, Juarez P; Figueiredo, Camila A; Figueiredo, Maria Aparecida A; Blanton, Ronald; Morato, Vanessa; Barreto, Maurício L; Rodrigues, Laura C

    2015-05-01

    Currently, knowledge does not allow early prediction of which cases of dengue fever (DF) will progress to dengue hemorrhagic fever (DHF), to allow early intervention to prevent progression or to limit severity. The objective of this study is to investigate the hypothesis that some specific comorbidities increase the likelihood of a DF case progressing to DHF. A concurrent case-control study, conducted during dengue epidemics, from 2009 to 2012. Cases were patients with dengue fever that progressed to DHF, and controls were patients of dengue fever who did not progress to DHF. Logistic regression was used to estimate the association between DHF and comorbidities. There were 490 cases of DHF and 1,316 controls. Among adults, progression to DHF was associated with self-reported hypertension (OR = 1.6; 95% CI 1.1-2.1) and skin allergy (OR = 1.8; 95% CI 1.1-3.2) with DHF after adjusting for ethnicity and socio-economic variables. There was no statistically significant association between any chronic disease and progression to DHF in those younger than 15 years. Physicians attending patients with dengue fever should keep those with hypertension or skin allergies in health units to monitor progression for early intervention. This would reduce mortality by dengue.

  12. Arterial Hypertension and Skin Allergy Are Risk Factors for Progression from Dengue to Dengue Hemorrhagic Fever: A Case Control Study

    PubMed Central

    Teixeira, Maria Glória; Paixão, Enny S.; Costa, Maria da Conceição N.; Cunha, Rivaldo V.; Pamplona, Luciano; Dias, Juarez P.; Figueiredo, Camila A.; Figueiredo, Maria Aparecida A.; Blanton, Ronald; Morato, Vanessa; Barreto, Maurício L.; Rodrigues, Laura C.

    2015-01-01

    Background Currently, knowledge does not allow early prediction of which cases of dengue fever (DF) will progress to dengue hemorrhagic fever (DHF), to allow early intervention to prevent progression or to limit severity. The objective of this study is to investigate the hypothesis that some specific comorbidities increase the likelihood of a DF case progressing to DHF. Methods A concurrent case-control study, conducted during dengue epidemics, from 2009 to 2012. Cases were patients with dengue fever that progressed to DHF, and controls were patients of dengue fever who did not progress to DHF. Logistic regression was used to estimate the association between DHF and comorbidities. Results There were 490 cases of DHF and 1,316 controls. Among adults, progression to DHF was associated with self-reported hypertension (OR = 1.6; 95% CI 1.1-2.1) and skin allergy (OR = 1.8; 95% CI 1.1-3.2) with DHF after adjusting for ethnicity and socio-economic variables. There was no statistically significant association between any chronic disease and progression to DHF in those younger than 15 years. Conclusions Physicians attending patients with dengue fever should keep those with hypertension or skin allergies in health units to monitor progression for early intervention. This would reduce mortality by dengue. PMID:25996882

  13. C1q binding to Dengue Virus inhibits infection of THP-1 and cellular inflammatory responses

    PubMed Central

    Douradinha, Bruno; McBurney, Sean P.; de Melo, Klecia M. Soares; Smith, Amanda P.; Krishna, Neel K.; Barratt-Boyes, Simon M.; Evans, Jared D.; Nascimento, Eduardo J. M.; Marques, Ernesto T. A

    2014-01-01

    Summary Dengue virus infection elicits a spectrum of clinical presentations ranging from asymptomatic to severe disease. The mechanisms leading to severe dengue are not known, however it has been reported that the complement system is hyper-activated in severe dengue. Screening of complement proteins demonstrated that C1q, a pattern recognition molecule, can bind directly to Dengue Virus Envelope protein and to whole Dengue Virus serotype 2. Incubation of Dengue Virus serotype 2 with C1q prior to infection of THP-1 cells led to decreased virus infectivity and modulation of mRNA expression of immunoregulatory molecules suggesting reduced inflammatory responses. PMID:24246304

  14. Dengue virus envelope protein domain I/II hinge: a key target for dengue virus vaccine design?

    PubMed

    Widman, Douglas G; Baric, Ralph S

    2015-01-01

    Dengue virus is the most significant arboviral pathogen worldwide with nearly 400 million infections annually and half the global population at risk of disease. Despite this tremendous public health burden, there are no licensed treatments or vaccines to prevent dengue in humans. Results from clinical trials of leading vaccine candidates have demonstrated that our current understanding of the correlates of protection from dengue is incomplete, and as such vaccine performance has been moderate, but with considerable room for improvement. Here we highlight new findings revealing key neutralizing epitopes that regulate serotype-specific immunity, and discuss their implications for design and evaluation of future vaccine candidates.

  15. Dengue prediction by the web: Tweets are a useful tool for estimating and forecasting Dengue at country and city level

    PubMed Central

    Degener, Carolin Marlen; Vinhal, Livia; Coelho, Giovanini; Meira, Wagner; Codeço, Claudia Torres; Teixeira, Mauro Martins

    2017-01-01

    Background Infectious diseases are a leading threat to public health. Accurate and timely monitoring of disease risk and progress can reduce their impact. Mentioning a disease in social networks is correlated with physician visits by patients, and can be used to estimate disease activity. Dengue is the fastest growing mosquito-borne viral disease, with an estimated annual incidence of 390 million infections, of which 96 million manifest clinically. Dengue burden is likely to increase in the future owing to trends toward increased urbanization, scarce water supplies and, possibly, environmental change. The epidemiological dynamic of Dengue is complex and difficult to predict, partly due to costly and slow surveillance systems. Methodology / Principal findings In this study, we aimed to quantitatively assess the usefulness of data acquired by Twitter for the early detection and monitoring of Dengue epidemics, both at country and city level at a weekly basis. Here, we evaluated and demonstrated the potential of tweets modeling for Dengue estimation and forecast, in comparison with other available web-based data, Google Trends and Wikipedia access logs. Also, we studied the factors that might influence the goodness-of-fit of the model. We built a simple model based on tweets that was able to ‘nowcast’, i.e. estimate disease numbers in the same week, but also ‘forecast’ disease in future weeks. At the country level, tweets are strongly associated with Dengue cases, and can estimate present and future Dengue cases until 8 weeks in advance. At city level, tweets are also useful for estimating Dengue activity. Our model can be applied successfully to small and less developed cities, suggesting a robust construction, even though it may be influenced by the incidence of the disease, the activity of Twitter locally, and social factors, including human development index and internet access. Conclusions Tweets association with Dengue cases is valuable to assist

  16. Dengue prediction by the web: Tweets are a useful tool for estimating and forecasting Dengue at country and city level.

    PubMed

    Marques-Toledo, Cecilia de Almeida; Degener, Carolin Marlen; Vinhal, Livia; Coelho, Giovanini; Meira, Wagner; Codeço, Claudia Torres; Teixeira, Mauro Martins

    2017-07-01

    Infectious diseases are a leading threat to public health. Accurate and timely monitoring of disease risk and progress can reduce their impact. Mentioning a disease in social networks is correlated with physician visits by patients, and can be used to estimate disease activity. Dengue is the fastest growing mosquito-borne viral disease, with an estimated annual incidence of 390 million infections, of which 96 million manifest clinically. Dengue burden is likely to increase in the future owing to trends toward increased urbanization, scarce water supplies and, possibly, environmental change. The epidemiological dynamic of Dengue is complex and difficult to predict, partly due to costly and slow surveillance systems. In this study, we aimed to quantitatively assess the usefulness of data acquired by Twitter for the early detection and monitoring of Dengue epidemics, both at country and city level at a weekly basis. Here, we evaluated and demonstrated the potential of tweets modeling for Dengue estimation and forecast, in comparison with other available web-based data, Google Trends and Wikipedia access logs. Also, we studied the factors that might influence the goodness-of-fit of the model. We built a simple model based on tweets that was able to 'nowcast', i.e. estimate disease numbers in the same week, but also 'forecast' disease in future weeks. At the country level, tweets are strongly associated with Dengue cases, and can estimate present and future Dengue cases until 8 weeks in advance. At city level, tweets are also useful for estimating Dengue activity. Our model can be applied successfully to small and less developed cities, suggesting a robust construction, even though it may be influenced by the incidence of the disease, the activity of Twitter locally, and social factors, including human development index and internet access. Tweets association with Dengue cases is valuable to assist traditional Dengue surveillance at real-time and low-cost. Tweets are

  17. [Susceptibility of natural populations of dengue vector to insecticides in Colombia].

    PubMed

    Santacoloma, Liliana; Chaves, Bernardo; Brochero, Helena Luisa

    2012-09-01

    Physiological resistance of natural population of Aedes aegypti to insecticides contribute to the decreased efficacy of chemical control as a main control strategy during dengue outbreaks. The susceptibility status of Ae. aegypti was assessed for the carbamate propoxur, the adulticide malathion and the larvicide temephos on 13 natural populations of Ae. aegypti immature forms were taken from 8 Colombian localities. These included the following: Bucaramanga (1), Sabana de Torres (2), Girardot (2), La Mesa (2), Villavicencio (2), Puerto López (2), San José del Guaviare (1) and Florencia (1). Susceptibility tests mainly consisted of the standardized bioassay outlined by WHO (1981) and CDC bottles (1998). Colorimetric tests were undertaken to determine enzyme levels possibly responsible for the reduction of susceptibility to organophosphate and carbamate insecticides. All specimens demonstrated susceptibility to malathion and propoxur insecticides. Four of the 13 populations revealed susceptibility to the temephos larvicide. Seven of 11 populations showed a limited increase in values for nonspecific esterase enzymes. The Bucaramanga population was the only one which showed an increase in the cytochrome P450 monooxygenases enzymes. Neither population was found with modified acetilcolinesterase. The widespread susceptibility to organophosphates used as adulticides indicated that malathion, the most used insecticide in Colombia, remains effective in interrupting the transmission of dengue. Physiological resistance to insecticides occurring in communities of a single township proved to be a localized phenomenon.

  18. Molecular epidemiology and evolutionary analysis of dengue virus type 2, circulating in Delhi, India.

    PubMed

    Sharma, Pankaj; Mittal, Veena; Chhabra, Mala; Kumari, Roop; Singh, Priyanka; Venkatesh, Srinivas

    2016-12-01

    Dengue virus type 2 (DENV-2) has been associated with severe dengue outbreaks in many countries including India. Its predominance was recorded nearly after a decade in the capital city, Delhi in 2013. The present study characterizes DENV-2 circulated during 2013-2014. Analysis based on envelope (E) gene showed the presence of two clades (I and II) of DENV-2, within the Cosmopolitan genotype. Analysis of time of most recent common ancestor revealed the existence of clade I for more than a decade (95 % HPD 13-16 years) however, clade II showed comparatively recent emergence (95 % HPD 5-13 years). Presence of different clades is of high significance as this may result in increased virus transmission and major outbreaks. Further, the presence of a unique amino acid substitution, Q325H was also observed in an isolate; 14/D2/Del/2013 (KT717981). This substitution falls in immune epitope (epitope id: 150268) and may have important role in host immune response.

  19. Clinical implications and treatment of dengue.

    PubMed

    Chawla, Pooja; Yadav, Amrita; Chawla, Viney

    2014-03-01

    Dengue is a common pathogenic disease often proving fatal, more commonly affecting the tropics. Aedes mosquito is the vector for this disease, and outbreaks of dengue often cause mass damage to life. The current review is an effort to present an insight into the causes, etiology, symptoms, transmission, diagnosis, major organs affected, mitigation and line of treatment of this disease with special emphasis on drugs of natural origin. The disease has a potential to spread as an endemic, often claiming several lives and thus requires concerted efforts to work out better treatment options. Traditional medicine offers an alternative solution and could be explored as a safer treatment option. Development of a successful vaccine and immunization technique largely remains a challenge and a better antiviral approach needs to be worked out to complement the supportive therapy. No single synthetic molecule has found to be wholly effective enough to offer curative control and the line of treatment mostly utilizes a combination of fluid replacement and antipyretics-analgesics like molecules to provide symptomatic relief. Copyright © 2014 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

  20. Mosquitoes infected with dengue viruses in Brazil

    PubMed Central

    2010-01-01

    Dengue epidemics have been reported in Brazil since 1985. The scenery has worsened in the last decade because several serotypes are circulating and producing a hyper-endemic situation, with an increase of DHF/DSS cases as well as the number of fatalities. Herein, we report dengue virus surveillance in mosquitoes using a Flavivirus genus-specific RT-Hemi-Nested-PCR assay. The mosquitoes (Culicidae, n = 1700) collected in the Northeast, Southeast and South of Brazil, between 1999 and 2005, were grouped into 154 pools. Putative genomes of DENV-1, -2 and -3 were detected in 6 mosquito pools (3.8%). One amplicon of putative DENV-1 was detected in a pool of Haemagogus leucocelaenus suggesting that this virus could be involved in a sylvatic cycle. DENV-3 was found infecting 3 pools of larvae of Aedes albopictus and the nucleotide sequence of one of these viruses was identified as DENV-3 of genotype III, phylogenetically related to other DENV-3 isolated in Brazil. This is the first report of a nucleotide sequence of DENV-3 from larvae of Aedes albopictus. PMID:20624314

  1. [Rapid centrifugation assay standarization for dengue virus isolation].

    PubMed

    Palomino, Miryam; Gutierrez, Victoria; Salas, Ramses

    2010-03-01

    The plate centrifugation assay was standardized for dengue virus isolation from serum samples. C6/36-HT cells were used determining the optimal values for centrifugation spin speed, inoculum, sera dilution, and incubation time. Then, 22 positive serum samples with viral isolation and viral strains of the four reference dengue virus serotypes were tested simultaneously by the standardized plate centrifugation method and the conventional tube culture. The isolations were typified by indirect immunofluorescent test using monoclonal antibodies. The plate centrifugation method was optimized to 200 μL of inoculum, dilution of sera 1/20, centrifugation speed at 1600 rpm/30 min, and sensitivity of 95,5% after 5 days post-inoculation. We concluded that the plate centrifugation method increased dengue virus isolation, with a significant reduction of the time of isolation for dengue virus.

  2. Help Control Mosquitoes that Spread Dengue, Chikungunya, and Zika Viruses

    MedlinePlus

    ... and annoying, the bite of an infected female mosquito ( Aedes aegypti or Aedes albopictus ) can spread dengue, ... or Zika after being bitten by an infected mosquito. • • Female mosquitoes lay several hundred eggs on the ...

  3. Risk mapping of dengue in Selangor and Kuala Lumpur, Malaysia.

    PubMed

    Hassan, Hafiz; Shohaimi, Shamarina; Hashim, Nor R

    2012-11-01

    Dengue fever is a recurring public health problem afflicting thousands of Malaysians annually. In this paper, the risk map for dengue fever in the peninsular Malaysian states of Selangor and Kuala Lumpur was modelled based on co-kriging and geographical information systems. Using population density and rainfall as the model's only input factors, the area with the highest risk for dengue infection was given as Gombak and Petaling, two districts located on opposite sides of Kuala Lumpur city that was also included in the risk assessment. Comparison of the modelled risk map with the dengue case dataset of 2010, obtained from the Ministry of Health of Malaysia, confirmed that the highest number of cases had been found in an area centred on Kuala Lumpur as predicted our risk profiling.

  4. Dengue vaccine: an update on recombinant subunit strategies.

    PubMed

    Martin, J; Hermida, L

    2016-03-01

    Dengue is an increasing public health problem worldwide, with the four serotypes of the virus infecting over 390 million people annually. There is no specific treatment or antiviral drug for dengue, and prevention is largely limited to controlling the mosquito vectors or disrupting the human-vector contact. Despite the considerable progress made in recent years, an effective vaccine against the virus is not yet available. The development of a dengue vaccine has been hampered by many unique challenges, including the need to ensure the absence of vaccine-induced enhanced severity of disease. Recombinant protein subunit vaccines offer a safer alternative to other vaccine approaches. Several subunit vaccine candidates are presently under development, based on different structural and non-structural proteins of the virus. Novel adjuvants or immunopotentiating strategies are also being tested to improve their immunogenicity. This review summarizes the current status and development trends of subunit dengue vaccines.

  5. Advances in the understanding, management, and prevention of dengue.

    PubMed

    Hermann, Laura L; Gupta, Swati B; Manoff, Susan B; Kalayanarooj, Siripen; Gibbons, Robert V; Coller, Beth-Ann G

    2015-03-01

    Dengue causes more human morbidity globally than any other vector-borne viral disease. Recent research has led to improved epidemiological methods that predict disease burden and factors involved in transmission, a better understanding of immune responses in infection, and enhanced animal models. In addition, a number of control measures, including preventative vaccines, are in clinical trials. However, significant gaps remain, including the need for better surveillance in large parts of the world, methods to predict which individuals will develop severe disease, and immunologic correlates of protection against dengue illness. During the next decade, dengue will likely expand its geographic reach and become an increasing burden on health resources in affected areas. Licensed vaccines and antiviral agents are needed in order to effectively control dengue and limit disease.

  6. Sliding window correlation analysis for dengue-climate variable relationship

    NASA Astrophysics Data System (ADS)

    Thiruchelvam, Loshini; Asirvadam, Vijanth S.; Dass, Sarat C.; Daud, Hanita; Gill, Balvinder S.

    2016-11-01

    This study discussed building of sliding windows to analyze the relationship between dengue incidences and weather variables of mean temperature, relative humidity and rainfall, across the timeline. A window sized of 20 was selected and applied to find correlation between dengue incidences and each of the weather variable. A few time lag of zero, two, four, six, and eight is compared and the time lag with best correlation is selected for each weather variable. Study did not found a good insight for analysis using mean temperature and relative humidity. For both these variables, it was suggested dengue incidences is better measured using fluctuation of maximum and minimum values. Analysis using rainfall variable was found to vary across the timeline in magnitude and direction of the correlation. Time lag of eight was found to be the most significant explaining the relationship between dengue incidences and rainfall variable.

  7. Spatial Variations in Dengue Transmission in Schools in Thailand

    PubMed Central

    Ratanawong, Pitcha; Kittayapong, Pattamaporn; Olanratmanee, Phanthip; Wilder-Smith, Annelies; Byass, Peter; Tozan, Yesim; Dambach, Peter; Quiñonez, Carlos Alberto Montenegro; Louis, Valérie R.

    2016-01-01

    Background Dengue is an important neglected tropical disease, with more than half of the world’s population living in dengue endemic areas. Good understanding of dengue transmission sites is a critical factor to implement effective vector control measures. Methods A cohort of 1,811 students from 10 schools in rural, semi-rural and semi-urban Thailand participated in this study. Seroconversion data and location of participants’ residences and schools were recorded to determine spatial patterns of dengue infections. Blood samples were taken to confirm dengue infections in participants at the beginning and the end of school term. Entomological factors included a survey of adult mosquito density using a portable vacuum aspirator during the school term and a follow up survey of breeding sites of Aedes vectors in schools after the school term. Clustering analyses were performed to detect spatial aggregation of dengue infections among participants. Results A total of 57 dengue seroconversions were detected among the 1,655 participants who provided paired blood samples. Of the 57 confirmed dengue infections, 23 (40.0%) occurred in students from 6 (6.8%) of the 88 classrooms in 10 schools. Dengue infections did not show significant clustering by residential location in the study area. During the school term, a total of 66 Aedes aegypti mosquitoes were identified from the 278 mosquitoes caught in 50 classrooms of the 10 schools. In a follow-up survey of breeding sites, 484 out of 2,399 water containers surveyed (20.2%) were identified as active mosquito breeding sites. Discussion and Conclusion Our findings suggest that dengue infections were clustered among schools and among classrooms within schools. The schools studied were found to contain a large number of different types of breeding sites. Aedes vector densities in schools were correlated with dengue infections and breeding sites in those schools. Given that only a small proportion of breeding sites in the schools

  8. Spatial Variations in Dengue Transmission in Schools in Thailand.

    PubMed

    Ratanawong, Pitcha; Kittayapong, Pattamaporn; Olanratmanee, Phanthip; Wilder-Smith, Annelies; Byass, Peter; Tozan, Yesim; Dambach, Peter; Quiñonez, Carlos Alberto Montenegro; Louis, Valérie R

    Dengue is an important neglected tropical disease, with more than half of the world's population living in dengue endemic areas. Good understanding of dengue transmission sites is a critical factor to implement effective vector control measures. A cohort of 1,811 students from 10 schools in rural, semi-rural and semi-urban Thailand participated in this study. Seroconversion data and location of participants' residences and schools were recorded to determine spatial patterns of dengue infections. Blood samples were taken to confirm dengue infections in participants at the beginning and the end of school term. Entomological factors included a survey of adult mosquito density using a portable vacuum aspirator during the school term and a follow up survey of breeding sites of Aedes vectors in schools after the school term. Clustering analyses were performed to detect spatial aggregation of dengue infections among participants. A total of 57 dengue seroconversions were detected among the 1,655 participants who provided paired blood samples. Of the 57 confirmed dengue infections, 23 (40.0%) occurred in students from 6 (6.8%) of the 88 classrooms in 10 schools. Dengue infections did not show significant clustering by residential location in the study area. During the school term, a total of 66 Aedes aegypti mosquitoes were identified from the 278 mosquitoes caught in 50 classrooms of the 10 schools. In a follow-up survey of breeding sites, 484 out of 2,399 water containers surveyed (20.2%) were identified as active mosquito breeding sites. Our findings suggest that dengue infections were clustered among schools and among classrooms within schools. The schools studied were found to contain a large number of different types of breeding sites. Aedes vector densities in schools were correlated with dengue infections and breeding sites in those schools. Given that only a small proportion of breeding sites in the schools were subjected to vector control measures (11%), this

  9. Evaluation of Nonstructural 1 Antigen Assays for the Diagnosis and Surveillance of Dengue in Singapore

    PubMed Central

    Pok, Kwoon-Yong; Lai, Yee-Ling; Sng, Joshua

    2010-01-01

    Abstract Early and accurate diagnosis of dengue is imperative for disease surveillance, which helps in the control of dengue in endemic countries. In this study, we evaluated the performance of three commercially available dengue nonstructural 1 (NS1) antigen assays (Bio-Rad Platelia™ Dengue NS1 Antigen ELISA, PanBio Dengue Early ELISA, and Bio-Rad Dengue NS1 Antigen Strip test) and compared them with reverse-transcription polymerase chain reaction (RT-PCR) and other commercially available serological assays for the diagnosis of dengue. The analysis showed RT-PCR to be the most sensitive and specific (100%) diagnostic method during the first 3 days of fever. The overall sensitivity of dengue NS1 antigen assays within the same period was 81.7%, indicating their potential role as a cost-effective and convenient alternative method to RT-PCR for the diagnosis of dengue fever in a primary healthcare setting. However, reduced sensitivity in detecting secondary dengue infections was one of the drawbacks of dengue NS1 antigen assays. Nonetheless, it remains a useful assay for the early detection of dengue and hence could play an important role in routine surveillance efforts to control dengue outbreaks in Singapore. PMID:20426686

  10. Hot spot detection and spatio-temporal dynamics of dengue in Queensland, Australia

    NASA Astrophysics Data System (ADS)

    Naish, S.; Tong, S.

    2014-11-01

    Dengue has been a major public health concern in Australia since it re-emerged in Queensland in 1992-1993. This study explored spatio-temporal distribution and clustering of locally-acquired dengue cases in Queensland State, Australia and identified target areas for effective interventions. A computerised locally-acquired dengue case dataset was collected from Queensland Health for Queensland from 1993 to 2012. Descriptive spatial and temporal analyses were conducted using geographic information system tools and geostatistical techniques. Dengue hot spots were detected using SatScan method. Descriptive spatial analysis showed that a total of 2,398 locally-acquired dengue cases were recorded in central and northern regions of tropical Queensland. A seasonal pattern was observed with most of the cases occurring in autumn. Spatial and temporal variation of dengue cases was observed in the geographic areas affected by dengue over time. Tropical areas are potential high-risk areas for mosquito-borne diseases such as dengue. This study demonstrated that the locally-acquired dengue cases have exhibited a spatial and temporal variation over the past twenty years in tropical Queensland, Australia. There is a clear evidence for the existence of statistically significant clusters of dengue and these clusters varied over time. These findings enabled us to detect and target dengue clusters suggesting that the use of geospatial information can assist the health authority in planning dengue control activities and it would allow for better design and implementation of dengue management programs.

  11. Epidemiology of Dengue Among Children Aged < 18 Months-Puerto Rico, 1999-2011.

    PubMed

    Hause, Anne M; Perez-Padilla, Janice; Horiuchi, Kalanthe; Han, George S; Hunsperger, Elizabeth; Aiwazian, Jonathan; Margolis, Harold S; Tomashek, Kay M

    2016-02-01

    Dengue, a mosquito-borne viral illness caused by dengue virus types (DENV)-1 to DENV-4, is endemic in Puerto Rico. Severe dengue usually occurs in individuals previously infected with DENV or among infants born to previously infected mothers. To describe clinical features of dengue in infants, we retrospectively characterized dengue patients aged < 18 months reported to the Passive Dengue Surveillance System (PDSS) during 1999-2011. To determine frequency of signs, symptoms, and disease severity, case report forms and medical records were evaluated for patients who tested positive for dengue by reverse transcriptase polymerase chain reaction or anti-DENV immunoglobulin Menzyme-linked immunosorbent assay. Of 4,178 reported patients aged < 18 months, 813 (19%) were laboratory positive. Of these, most had fever (92%), rash (53%), bleeding manifestations (52%), and thrombocytopenia (52%). Medical records were available for 145 (31%) of 472 hospitalized patients, of which 40% had dengue, 23% had dengue with warning signs, and 33% had severe dengue. Mean age of patients with severe dengue was 8 months. Anti-DENV immunoglobulin G (IgG) titers were not statistically different in patients with (50%) and without (59%) severe dengue. In this study, one-third of DENV-infected infants met the severe dengue case definition. The role of maternal anti-DENV IgG in development of severe disease warrants further study in prospective cohorts of mother-infant pairs.

  12. Role of Humoral versus Cellular Responses Induced by a Protective Dengue Vaccine Candidate

    PubMed Central

    Zellweger, Raphaël M.; Miller, Robyn; Eddy, William E.; White, Laura J.; Johnston, Robert E.; Shresta, Sujan

    2013-01-01

    With 2.5 billion people at risk, dengue is a major emerging disease threat and an escalating public health problem worldwide. Dengue virus causes disease ranging from a self-limiting febrile illness (dengue fever) to the potentially fatal dengue hemorrhagic fever/dengue shock syndrome. Severe dengue disease is associated with sub-protective levels of antibody, which exacerbate disease upon re-infection. A dengue vaccine should generate protective immunity without increasing severity of disease. To date, the determinants of vaccine-mediated protection against dengue remain unclear, and additional correlates of protection are urgently needed. Here, mice were immunized with viral replicon particles expressing the dengue envelope protein ectodomain to assess the relative contribution of humoral versus cellular immunity to protection. Vaccination with viral replicon particles provided robust protection against dengue challenge. Vaccine-induced humoral responses had the potential to either protect from or exacerbate dengue disease upon challenge, whereas cellular immune responses were beneficial. This study explores the immunological basis of protection induced by a dengue vaccine and suggests that a safe and efficient vaccine against dengue should trigger both arms of the immune system. PMID:24204271

  13. Transient CD4/CD8 ratio inversion and aberrant immune activation during dengue virus infection.

    PubMed

    Liu, Ching-Chuan; Huang, Kao-Jean; Lin, Yee-Shin; Yeh, Trai-Ming; Liu, Hsiao-Sheng; Lei, Huan-Yao

    2002-10-01

    The immune status after dengue virus infection was studied in dengue patients from an outbreak of serotype 3 dengue virus infection in the southern part of Taiwan during November and December 1998. Consecutive blood samples from 29 dengue patients, of whom 21 had dengue fever and 8 had dengue hemorrhagic fever/dengue shock syndrome, were collected, and the immunophenotypes of the peripheral blood mononuclear cells were determined by flow cytometry. The early activation marker CD69 appeared on lymphocytes and monocytes at day 4 after the onset of fever, and declined afterward. However, a transient reverse in the CD4/CD8 ratio occurred at days 6-10 after the onset of fever. The CD4/CD8 ratio inversion was manifested in 10 of 29 dengue patients and was encountered more frequently in dengue hemorrhagic fever/dengue shock syndrome than in dengue fever patients. Analysis of the clinical blood cell count of these 10 cases showed that increase of immature neutrophils developed at fever days 5-6, CD4(dim) or CD8(dim) monocytosis at days 6-7, and atypical lymphocytosis at days 8-10 after the onset of fever. Serum IL-6 was found at either day 7 or day 9-11. The PHA-stimulated T-cell response was depressed as well. These changes in immune parameters indicate aberrant immune activation during dengue virus infection and might be involved in the pathogenesis of dengue virus infection.

  14. Rural-urban comparisons of dengue seroprevalence in Malaysia.

    PubMed

    Chew, Cheng Hoon; Woon, Yuan Liang; Amin, Faridah; Adnan, Tassha H; Abdul Wahab, Asmah Hani; Ahmad, Zul Edzhar; Bujang, Mohd Adam; Abdul Hamid, Abdul Muneer; Jamal, Rahman; Chen, Wei Seng; Hor, Chee Peng; Yeap, Lena; Hoo, Ling Ping; Goh, Pik Pin; Lim, Teck Onn

    2016-08-18

    Each year an estimated 390 million dengue infections occur worldwide. In Malaysia, dengue is a growing public health concern but estimate of its disease burden remains uncertain. We compared the urban-rural difference of dengue seroprevalence and determined age-specific dengue seroprevalence in Malaysia. We undertook analysis on 11,821 subjects from six seroprevalence surveys conducted in Malaysia between 2001 and 2013, which composed of five urban and two rural series. Prevalence of dengue increased with age in both urban and rural locations in Malaysia, which exceeded 90 % among those aged 70 years or beyond. The age-specific rates of the 5 urban surveys overlapped without clear separation among them, while prevalence was lower in younger subjects in rural series than in urban series, the trend reversed in older subjects. There were no differences in the seroprevalence by gender, ethnicity or region. Poisson regression model confirmed the prevalence have not changed in urban areas since 2001 but in rural areas, there was a significant positive time trend such that by year 2008, rural prevalence was as high as in urban areas. Dengue seroprevalence has stabilized but persisted at a high level in urban areas since 2001, and is fast stabilizing in rural areas at the same high urban levels by 2008. The cumulative seroprevalence of dengue exceeds 90 % by the age of 70 years, which translates into 16.5 million people or 55 % of the total population in Malaysia, being infected by dengue by 2013.

  15. Differential Dengue Tropism & Neutralization: Potential Mechanisms of Pathogenesis

    DTIC Science & Technology

    2006-01-04

    demonstrate that sub-neutralizing concentrations of antibodies in vitro and in primates increased virus titers (97, 99, 100). Studies have shown that dengue...replicate less efficiently than the parental virus in non-human primate cells (28). Further, neuroadaptation of dengue 1 virus resulted in mutations in...immune sera from various non-human primate (NHP) and human studies were used in some experiments. Pooled antiDEN-2 sera was obtained from rhesus

  16. Prediction of high incidence of dengue in the Philippines.

    PubMed

    Buczak, Anna L; Baugher, Benjamin; Babin, Steven M; Ramac-Thomas, Liane C; Guven, Erhan; Elbert, Yevgeniy; Koshute, Phillip T; Velasco, John Mark S; Roque, Vito G; Tayag, Enrique A; Yoon, In-Kyu; Lewis, Sheri H

    2014-04-01

    Accurate prediction of dengue incidence levels weeks in advance of an outbreak may reduce the morbidity and mortality associated with this neglected disease. Therefore, models were developed to predict high and low dengue incidence in order to provide timely forewarnings in the Philippines. Model inputs were chosen based on studies indicating variables that may impact dengue incidence. The method first uses Fuzzy Association Rule Mining techniques to extract association rules from these historical epidemiological, environmental, and socio-economic data, as well as climate data indicating future weather patterns. Selection criteria were used to choose a subset of these rules for a classifier, thereby generating a Prediction Model. The models predicted high or low incidence of dengue in a Philippines province four weeks in advance. The threshold between high and low was determined relative to historical incidence data. Model accuracy is described by Positive Predictive Value (PPV), Negative Predictive Value (NPV), Sensitivity, and Specificity computed on test data not previously used to develop the model. Selecting a model using the F0.5 measure, which gives PPV more importance than Sensitivity, gave these results: PPV = 0.780, NPV = 0.938, Sensitivity = 0.547, Specificity = 0.978. Using the F3 measure, which gives Sensitivity more importance than PPV, the selected model had PPV = 0.778, NPV = 0.948, Sensitivity = 0.627, Specificity = 0.974. The decision as to which model has greater utility depends on how the predictions will be used in a particular situation. This method builds prediction models for future dengue incidence in the Philippines and is capable of being modified for use in different situations; for diseases other than dengue; and for regions beyond the Philippines. The Philippines dengue prediction models predicted high or low incidence of dengue four weeks in advance of an outbreak with high accuracy, as measured by PPV

  17. Assessing Weather Effects on Dengue Disease in Malaysia

    PubMed Central

    Cheong, Yoon Ling; Burkart, Katrin; Leitão, Pedro J.; Lakes, Tobia

    2013-01-01

    The number of dengue cases has been increasing on a global level in recent years, and particularly so in Malaysia, yet little is known about the effects of weather for identifying the short-term risk of dengue for the population. The aim of this paper is to estimate the weather effects on dengue disease accounting for non-linear temporal effects in Selangor, Kuala Lumpur and Putrajaya, Malaysia, from 2008 to 2010. We selected the weather parameters with a Poisson generalized additive model, and then assessed the effects of minimum temperature, bi-weekly accumulated rainfall and wind speed on dengue cases using a distributed non-linear lag model while adjusting for trend, day-of-week and week of the year. We found that the relative risk of dengue cases is positively associated with increased minimum temperature at a cumulative percentage change of 11.92% (95% CI: 4.41–32.19), from 25.4 °C to 26.5 °C, with the highest effect delayed by 51 days. Increasing bi-weekly accumulated rainfall had a positively strong effect on dengue cases at a cumulative percentage change of 21.45% (95% CI: 8.96, 51.37), from 215 mm to 302 mm, with the highest effect delayed by 26–28 days. The wind speed is negatively associated with dengue cases. The estimated lagged effects can be adapted in the dengue early warning system to assist in vector control and prevention plan. PMID:24287855

  18. The Hidden Burden of Dengue and Chikungunya in Chennai, India

    PubMed Central

    Rodríguez-Barraquer, Isabel; Solomon, Sunil S.; Kuganantham, Periaswamy; Srikrishnan, Aylur Kailasom; Vasudevan, Canjeevaram K.; Iqbal, Syed H.; Balakrishnan, Pachamuthu; Solomon, Suniti; Mehta, Shruti H.; Cummings, Derek A. T.

    2015-01-01

    Background Dengue and chikungunya are rapidly expanding viruses transmitted by mosquitoes of the genus Aedes. Few epidemiological studies have examined the extent of transmission of these infections in South India despite an increase in the number of reported cases, and a high suitability for transmission. Methods and findings We conducted a household-based seroprevalence survey among 1010 individuals aged 5-40 years living in fifty randomly selected spatial locations in Chennai, Tamil Nadu. Participants were asked to provide a venous blood sample and to complete a brief questionnaire with basic demographic and daily activity information. Previous exposure to dengue and chikungunya was determined using IgG indirect ELISA (Panbio) and IgG ELISA (Novatec), respectively. We used this data to estimate key transmission parameters (force of infection and basic reproductive number) and to explore factors associated with seropositivity. While only 1% of participants reported history of dengue and 20% of chikungunya, we found that 93% (95%CI 89-95%) of participants were seropositive to dengue virus, and 44% (95%CI 37-50%) to chikungunya. Age-specific seroprevalence was consistent with long-tem, endemic circulation of dengue and suggestive of epidemic chikungunya transmission. Seropositivity to dengue and chikungunya were significantly correlated, even after adjusting for individual and household factors. We estimate that 23% of the susceptible population gets infected by dengue each year, corresponding to approximately 228,000 infections. This transmission intensity is significantly higher than that estimated in known hyperendemic settings in Southeast Asia and the Americas. Conclusions These results provide unprecedented insight into the very high transmission potential of dengue and chikungunya in Chennai and underscore the need for enhanced surveillance and control methods. PMID:26181441

  19. Detection of dengue virus type 4 in Easter Island, Chile.

    PubMed

    Fernández, J; Vera, L; Tognarelli, J; Fasce, R; Araya, P; Villagra, E; Roos, O; Mora, J

    2011-10-01

    We report the detection of dengue virus type 4 (DENV-4) for the first time in Easter Island, Chile. The virus was detected in serum samples of two patients treated at the Hospital in Easter Island. The two samples were IgM positive, and the infection was confirmed by RT-PCR and genetic sequencing; viral isolation was possible with one of them. The Easter Island isolates were most closely related to genotype II of dengue type 4.

  20. DENGUE DURING PREGNANCY: ASSOCIATION WITH LOW BIRTH WEIGHT AND PREMATURITY

    PubMed Central

    RIBEIRO, Christiane Fernandes; LOPES, Vânia Glória Silami; Brasil, Patricia; da Silva, Licinio Esmeraldo; RIBEIRO, Pedro Henrique Fernandes Josephson; UGENTI, Luca Cipriani; NOGUEIRA, Rita Maria Ribeiro

    2016-01-01

    The aim of this study was to evaluate the effects of dengue virus infection during pregnancy and its correlation with low birth weight, prematurity, and asphyxia. A non-concurrent cohort study reveals the association of dengue during pregnancy with prematurity and low birth weight, when birth occurred during the maternal-fetal viremia period (p = 0.016 and p < 0.0001, respectively). PMID:26910454

  1. A preliminary study of dengue infection in Brunei.

    PubMed

    Osman, Osmali; Fong, Mun Yik; Devi, Shamala

    2007-07-01

    The purpose of this study was to examine the extent of dengue infection in Brunei and to determine the predominant serotype circulating in the country. The study generated useful epidemiological data on dengue infection in Brunei. A total of 271 samples from patients suspected of having dengue infections were selected and analyzed. All patients were seen in clinics and hospitals in Brunei. The samples were collected from April 2005 to April 2006 and transported to the WHO Collaborating Centre for Arbovirus Reference and Research, University of Malaya, Malaysia. The following tests were used to achieve the objectives: in-house IgM-capture enzyme-linked immunosorbent assay, virus isolation in mosquito albopictus cell line (C6/36), and viral RNA detection and serotyping by reverse transcriptase-polymerase chain reaction (RT-PCR). The results show that 45 people were positive for dengue-specific IgM (27 males and 18 females), while RT-PCR detected dengue viral RNA in 12 patients, 3 identified as DEN-1 and 9 as DEN-2. Dengue virus was isolated from 6 patients using the C6/36 cell line; 3 were DEN-2 isolates and 3 were DEN-1 isolates. These data show that dengue virus is circulating in Brunei and the predominant infecting serotype for that period was DEN-2 followed by DEN-1. This study is the first to report the detection and isolation of dengue virus from Brunei using RT-PCR and culture in the C6/36 albopictus mosquito cell line.

  2. A novel indirect ELISA for diagnosis of dengue fever.

    PubMed

    Narayan, Rohan; Raja, Senthil; Kumar, Senthil; Sambasivam, Mohana; Jagadeesan, Raja; Arunagiri, Kavita; Krishnasamy, Kaveri; Palani, Gunasekaran

    2016-07-01

    Dengue fever (DF) is associated with significant morbidity and mortality in the tropical and sub-tropical regions of the world. Since there are no effective antiviral drugs for treatment, clinicians often rely on the accurate diagnosis of dengue fever to begin supportive therapy at early stages of the illness. The objective of this study was to develop an in-house dengue virus serotype 2 (DENV-2) non-structural protein- 5 (NS5) based indirect ELISA. DENV-2 was raised in Vero cells and the viral proteins were separated and subsequently the NS5 protein was eluted. Serum samples from primary and secondary dengue fever patients; and acute and convalescent samples from Japanese encephalitis (JE) and West Nile virus (WNV) cases were used to validate the ELISA. The assay was found to be 100 per cent specific in detecting DENV-2 specific antibodies from patient's serum. However, in terms of sensitivity, the assay could detect IgM antibodies only from 90 per cent of the primary dengue samples. The IgM/IgG ratio of the primary and secondary samples was 7.24 and 0.64, respectively. The results indicate that the DENV-2 NS5 ELISA is dengue group specific and can be used to differentiate dengue infection from other circulating Flavivirus infections. This NS5 ELISA can also be used to distinguish between primary and secondary dengue fever on the basis of IgM/IgG ratios. Further studies with larger sample sizes and different DENV serotypes are required to validate the ELISA.

  3. Distribution, seasonal variation & dengue transmission prediction in Sisaket, Thailand

    PubMed Central

    Wongkoon, S.; Jaroensutasinee, M.; Jaroensutasinee, K.

    2013-01-01

    Background & objectives: Environmental factors including weather variables may play a significant role in the transmission of dengue. This study investigated the effect of seasonal variation on the abundance of Aedes aegypti and Ae. albopictus larvae and explored the impact of weather variability on dengue transmission in Sisaket, Thailand. Methods: The monthly mosquito larval surveys were carried out in urban and rural areas in Sisaket, Thailand from January to December 2010. Data on monthly-reported cases of dengue fever over the period 2004-2010 were obtained from the Ministry of Public Health. Weather data over the same period were obtained from the Thai Meteorological Department. Chi-square test was used to find the differences relating to seasonal variability, areas of study, and mosquito species factors using entomological survey data. Time series Poisson regression analysis was performed using data on monthly weather variables and dengue cases. Results: There were more Ae. aegypti larvae per household than Ae. albopictus larvae in the winter and rainy seasons. More Aedes larvae per household were found in the rainy season than in the winter and summer seasons. Relative humidity at a lag of one month and rainy days in the current month were significant predictors of dengue incidence in Sisaket. Interpretation & conclusions: Increased rain during the current month and less humidity during the previous month might trigger a higher incidence of dengue epidemic in Sisaket. The present findings suggest that the dengue incidence corresponds with the number of Aedes larvae. The seasonal patterns of dengue outbreaks coincide with the rainy season. PMID:24135179

  4. DENGUE DURING PREGNANCY: ASSOCIATION WITH LOW BIRTH WEIGHT AND PREMATURITY.

    PubMed

    Ribeiro, Christiane Fernandes; Lopes, Vânia Glória Silami; Brasil, Patricia; Silva, Licinio Esmeraldo da; Ribeiro, Pedro Henrique Fernandes Josephson; Ugenti, Luca Cipriani; Nogueira, Rita Maria Ribeiro

    2016-01-01

    The aim of this study was to evaluate the effects of dengue virus infection during pregnancy and its correlation with low birth weight, prematurity, and asphyxia. A non-concurrent cohort study reveals the association of dengue during pregnancy with prematurity and low birth weight, when birth occurred during the maternal-fetal viremia period (p = 0.016 and p < 0.0001, respectively).

  5. Prevention and control of influenza and dengue through vaccine development.

    PubMed

    Greenberg, David P; Robertson, Corwin A; Gordon, Daniel M

    2013-08-01

    Influenza and dengue are viral illnesses of global public health importance, especially among children. Accordingly, these diseases have been the focus of efforts to improve their prevention and control. Influenza vaccination offers the best protection against clinical disease caused by strains contained within the specific year's formulation. It is not uncommon for there to be a mismatch between vaccine strains and circulating strains, particularly with regards to the B lineages. For more than a decade, two distinct lineages of influenza B (Yamagata and Victoria) have co-circulated in the US with varying frequencies, but trivalent influenza vaccines contain only one B-lineage strain and do not offer adequate protection against the alternate B-lineage. Quadrivalent influenza vaccines (QIVs), containing two A strains (H1N1 and H3N2) and two B strains (one from each lineage) have been developed to help protect against the four strains predicted to be the most likely to be circulating. The QIV section of this article discusses epidemiology of pediatric influenza, importance of influenza B in children, potential benefits of QIV, and new quadrivalent vaccines. In contrast to influenza, a vaccine against dengue is not yet available in spite of many decades of research and development. A global increase in reports of dengue fever (DF) and its more severe presentations, dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS), suggest that US physicians will increasingly encounter patients with this disease. Similarities of the early signs and symptoms of influenza and dengue and the differences in disease management necessitates a better understanding of the epidemiology, clinical presentation, management, and prevention of DF by US physicians, including pediatricians. The article also provides a brief overview of dengue and discusses dengue vaccine development.

  6. Cost-Effectiveness of Dengue Vaccination Programs in Brazil.

    PubMed

    Shim, Eunha

    2017-05-01

    AbstractThe first approved dengue vaccine, CYD-TDV, a chimeric, live-attenuated, tetravalent dengue virus vaccine, was recently licensed in 13 countries, including Brazil. In light of recent vaccine approval, we modeled the cost-effectiveness of potential vaccination policies mathematically based on data from recent vaccine efficacy trials that indicated that vaccine efficacy was lower in seronegative individuals than in seropositive individuals. In our analysis, we investigated several vaccination programs, including routine vaccination, with various vaccine coverage levels and those with and without large catch-up campaigns. As it is unclear whether the vaccine protects against infection or just against disease, our model incorporated both direct and indirect effects of vaccination. We found that in the presence of vaccine-induced indirect protection, the cost-effectiveness of dengue vaccination decreased with increasing vaccine coverage levels because the marginal returns of herd immunity decreases with vaccine coverage. All routine dengue vaccination programs that we considered were cost-effective, reducing dengue incidence significantly. Specifically, a routine dengue vaccination of 9-year-olds would be cost-effective when the cost of vaccination per individual is less than $262. Furthermore, the combination of routine vaccination and large catch-up campaigns resulted in a greater reduction of dengue burden (by up to 93%) than routine vaccination alone, making it a cost-effective intervention as long as the cost per course of vaccination is $255 or less. Our results show that dengue vaccination would be cost-effective in Brazil even with a relatively low vaccine efficacy in seronegative individuals.

  7. Locally acquired Dengue--Key West, Florida, 2009-2010.

    PubMed

    2010-05-21

    Dengue is the most common vector-borne viral disease in the world, causing an estimated 50-100 million infections and 25,000 deaths each year. During 1946-1980, no cases of dengue acquired in the continental United States were reported. Since 1980, a few locally acquired U.S. cases have been confirmed along the Texas-Mexico border, temporally associated with large outbreaks in neighboring Mexican cities. On September 1, 2009, a New York physician notified the Monroe County (Florida) Health Department (MCHD) and the Florida Department of Health (FDOH) of a suspected dengue case in a New York state resident whose only recent travel was to Key West, Florida. CDC confirmed the diagnosis, and a press release was issued to notify the public and Key West physicians of the potential risk for locally acquired dengue infections. In the next 2 weeks, two dengue infections in Key West residents without recent travel were reported and confirmed. Subsequently, enhanced and active surveillance identified 24 more Key West cases during 2009. On April 13, 2010, another Key West dengue case was reported to FDOH, bringing the total to 28. This report describes the first three dengue cases reported in 2009, briefly summarizes the 2010 case, highlights preliminary findings from the ongoing investigation, and outlines measures used to mitigate and control the outbreak. Clinicians should include dengue in the differential diagnosis of acute febrile illnesses in patients who live in or have recently traveled to subtropical areas of the United States or to the tropics.

  8. Treatment Effectiveness of Amantadine Against Dengue Virus Infection

    PubMed Central

    Lin, Chieh-Cheng; Chen, Wen-Ching

    2016-01-01

    Case series Patient: — Final Diagnosis: Dengue fever infection Symptoms: Bone pain • fever Medication: — Clinical Procedure: — Specialty: Infectious Diseases Objective: Unusual or unexpected effect of treatment Background: About 400 million cases of dengue, a mosquito-borne disease, are reported annually, but no drug is yet available for treatment. In 1988, at Feng Lin Clinic, Taiwan, we encountered about 10,000 cases and tested various drugs before confirming an antiviral effect of amantadine against dengue virus in vitro. After we administered amantadine to patients for 1–2 days, most achieved full remission. None experienced potentially life-threatening dengue hemorrhagic fever or dengue shock syndrome. Herein, we present 34 cases from recent clinical experience that show amantadine’s unusual effect against dengue virus infection. Case Report: We divided 34 patients with symptoms of dengue fever, confirmed by a screening test, into 3 groups: 6 Category 1 patients received amantadine at onset, 21 Category 2 patients received amantadine within 2–6 days, and 7 Contrast group patients received no amantadine because they visited other clinics or were admitted to a large hospital. When Category 1 patients were treated with amantadine 100 mg 3 times per day, all symptoms dramatically subsided within 1–2 days. In Category 2 patients, most symptoms diminished within 1–2 days after starting the same regimen. In the Contrast group, all symptoms persisted 7 days after onset. White blood cell and platelet counts in Category 1 and 2 patients recovered to normal range, but remained below low normal in the Contrast group. Conclusions: Amantadine is effective and should be given as soon as possible to stop the disease course if dengue fever is confirmed through screening or clinical signs and symptoms. A well-designed larger sample study is warranted to test this effectiveness. PMID:27920420

  9. Molecular surveillance of Dengue in Sukabumi, West Java province, Indonesia.

    PubMed

    Nusa, Roy; Prasetyowati, Heni; Meutiawati, Febrina; Yohan, Benediktus; Trimarsanto, Hidayat; Setianingsih, Tri Yuli; Sasmono, R Tedjo

    2014-06-11

    Dengue is endemic and affects people in all Indonesian provinces. Increasing dengue cases have been observed every year in Sukabumi in West Java province. Despite the endemicity, limited data is available on the genetic of dengue viruses (DENV) circulating in the country. To understand the dynamics of dengue disease, we performed molecular and serological surveillance of dengue in Sukabumi. A total of 113 patients were recruited for this study. Serological data were obtained using anti-dengue IgM and IgG tests plus dengue NS1 antigen detection. Dengue detection and serotyping were performed using real-time RT-PCR. Viruses were isolated and the envelope genes were sequenced. Phylogenetic and evolutionary analyses were performed to determine the genotype of the viruses and their evolutionary rates. Real-time RT-PCR detected DENV in 25 (22%) of 113 samples. Serotyping revealed the predominance of DENV-2 (16 isolates, 64%), followed by DENV-1 (5 isolates, 20%), and DENV-4 (4 isolates, 16%). No DENV-3 was detected in the samples. Co-circulation of genotype I and IV of DENV-1 was observed. The DENV-2 isolates all belonged to the Cosmopolitan genotype, while DENV-4 isolates were grouped into genotype II. Overall, their evolutionary rates were similar to DENV from other countries. We revealed the distribution of DENV serotypes and genotypes in Sukabumi. Compared to data obtained from other cities in Indonesia, we observed the differing predominance of DENV serotypes but similar genotype distribution, where the infecting viruses were closely related with Indonesian endemic viruses isolated previously.

  10. Molecular epidemiology of dengue in Jamaica dengue virus genotypes in Jamaica, 2007.

    PubMed

    Brown, M G; Salas, R A; Vickers, I E; Heslop, O D; Smikle, M F

    2011-03-01

    The genotypes of dengue viruses (DENV) isolated from patients with dengue in Jamaica during 2007 were determined using DNA sequencing and phylogenetic analysis of the C-prM gene junction. The 17 DENV analysed included strains of DENVserotypes 1 (DENV-1, n = 3), DENV-2 (n = 7) and DENV-4 (n = 7). All strains ofDENV-1 were classified as genotype III, while 1 of 7 strains of DENV-2 belonged to the Asian American/Asian genotype, genotype I/III (Jamaica genotype), 2 were genotype V, the American genotype and 4 strains clustered with reference strains belonging to genotype IV. The 6 DENV-4 strains from Jamaica and the control strain clustered together in a separate clade from Caribbean/American reference strains, which belong to genotype II and Asian strains, classified as genotypes I and III. There has been little evolution in the DENV-1 strains circulating in Jamaica over the years and this might reduce the risk of outbreaks due to this serotype. In contrast, the high genetic diversity in strains of DENV-2 viruses in circulation, the presence of more recently introduced genotypes and a new clade of DENV-4 might contribute to the epidemic potential of these DENV serotypes. These preliminary data clearly indicate the need to maintain laboratory surveillance, and other control measures against hyperendemicity of dengue in Jamaica.

  11. Superinfection interference between dengue-2 and dengue-4 viruses in Aedes aegypti mosquitoes.

    PubMed

    Muturi, Ephantus J; Buckner, Eva; Bara, Jeffrey

    2017-04-01

    Dengue virus consists of four antigenically distinct serotypes (DENV 1-4) that are transmitted to humans by Aedes aegypti and Aedes albopictus mosquitoes. In many dengue-endemic regions, co-circulation of two or more DENV serotypes is fairly common increasing the likelihood for exposure of the two vectors to multiple serotypes. We used a model system of DENV-2 and DENV-4 to investigate how prior exposure of Aedes aegypti to one DENV serotype affects its susceptibility to another serotype. Aedes aegypti mosquitoes were sequentially infected with DENV-2 and DENV-4 and the infection and dissemination rates for each virus determined. We found that prior infection of Ae. aegypti mosquitoes with DENV-4 rendered them significantly less susceptible to secondary infection with DENV-2. Although the results were not statistically significant, mosquitoes infected with DENV-2 were also less susceptible to secondary infection with DENV-4. The midgut dissemination and population dissemination rates for DENV-2 were significantly higher than those of DENV-4 when either virus was administered 7 days after administration of either a non-infectious blood meal or a blood meal containing a heterologous dengue serotype. These results demonstrate that superinfection interference between DENV serotypes is possible within Ae. aegypti mosquitoes, but its effect on DENV epidemiology may be dependent on the fitness of interacting serotypes. © 2017 John Wiley & Sons Ltd.

  12. Epidemic dengue and dengue hemorrhagic fever at the Texas-Mexico border: results of a household-based seroepidemiologic survey, December 2005.

    PubMed

    Ramos, Mary M; Mohammed, Hamish; Zielinski-Gutierrez, Emily; Hayden, Mary H; Lopez, Jose Luis Robles; Fournier, Marta; Trujillo, Alfredo Rodríguez; Burton, Roy; Brunkard, Joan M; Anaya-Lopez, Luis; Banicki, Allison Abell; Morales, Pablo Kuri; Smith, Brian; Muñoz, Jorge L; Waterman, Stephen H

    2008-03-01

    A dengue-2 epidemic causing dengue hemorrhagic fever (DHF) occurred in the contiguous border cities of Matamoros, Tamaulipas (Mexico), and Brownsville, TX, in 2005. In December, we conducted a household-based epidemiologic survey to determine the incidence and seroprevalence of dengue infection among Matamoros and Brownsville residents and to identify risk factors associated with infection. Antibodies to dengue were measured in 273 individuals. The estimated incidence of recent dengue infection was 32% and 4% among Matamoros and Brownsville participants, respectively. The estimated prevalence of past dengue infection was 77% and 39% among Matamoros and Brownsville participants, respectively. The Breteau index was 28 in Matamoros and 16 in Brownsville, reflecting an abundant winter population of Aedes mosquitoes. Discarded waste tires and buckets were the two largest categories of infested containers found in both cities. Our results underscore the risk for epidemic dengue and DHF in the Texas-Mexico border region.

  13. A potential risk assessment of a dengue outbreak in north central Texas, USA. (Part 1 of 2): Abundance and temporal variation of dengue vectors.

    PubMed

    Lee, Joon-Hak; Stahl, Matt; Sawlis, Scott; Suzuki, Sumi; Lee, Jib Ho

    2009-06-01

    In response to three imported dengue cases in north central Texas as well as increased case numbers in Texas and adjoining Mexican states in 2005, the authors assessed the potential risk of a dengue outbreak in north central Texas by investigating abundance and temporal variation of dengue vectors in 2006. Dengue vector abundance was monitored from 54 sites in Dallas County, Texas, from June to November 2006, using oviposition traps. Both dengue vectors--the yellow fever mosquito, Aedes aegypti, and the Asian tiger mosquito, Aedes albopictus--were present. Of the two, Ae. albopictus was more abundant and its abundance appeared to be positively affected by temperature and precipitation. Potential risk of a dengue outbreak was predicted based on the abundance and temporal variation of dengue vectors and a long-term trend of breeding season precipitation and warmer winter temperatures.

  14. Memories of Astronomy Education in Brazil: Clippings from the Discourses of Interviewed Researchers on the Subject. (Spanish Title: Memorias de la Educación en Astronomía en Brasil: Recortes de los Discursos de Investigadores Entrevistados Acerca del Tema ) Memórias da Educação em Astronomia no Brasil: Recortes a Partir das Falas de Pesquisadores Entrevistados sobre o Tema

    NASA Astrophysics Data System (ADS)

    Iachel, Gustavo; Nardi, Roberto

    2014-12-01

    This paper presents a historical retrospective concerning data from a research in Astronomy Education in Brazil, after 1973. It was organized on the basis of the speech analysis of national researchers considered references in this field by their peers. Furthermore, it was elaborated on the basis of other studies from the areas of Science Education, Physics and Astronomy. This historical overview was developed in order to facilitate understanding of the contexts in which the interviewed researchers have developed professionally. Moreover, we attempted to recover the memory of the growing field of research in Astronomy Education in the country. We believe that the history presented can help those trying to understand the past in an attempt to resolve current and future demands. Se presenta en este artículo una retrospectiva histórica referente a datos provenientes de la investigación en enseñanza de la astronomía en el Brasil, después de 1973, organizada sobre la base del análisis de los discursos de los investigadores nacionales considerados referencias en este campo, y también en la lectura de las publicaciones en las áreas de Enseñanza de las Ciencias, Física y Astronomía. Este repaso histórico se desarrolló con el fin de facilitar la comprensión de los contextos en los que los investigadores entrevistados se han desarrollado profesionalmente. Por otra parte, se intentó recuperar la memoria del creciente campo de la investigación en Educación en Astronomía en el país. Creemos que el relato presentado puede contribuir a quien trata de comprender el pasado, en un intento de resolver las demandas actuales y futuras. Relata-se neste artigo uma retrospectiva histórica referente a dados provenientes de pesquisa em Educação em Astronomia no país, pós 1973, organizada com base na análise das falas de pesquisadores considerados referências nacionais nesse campo, como também na leitura de publicações das áreas de ensino de Ciências, F

  15. Acute hemorrhagic encephalitis: An unusual presentation of dengue viral infection

    PubMed Central

    Nadarajah, Jeyaseelan; Madhusudhan, Kumble Seetharama; Yadav, Ajay Kumar; Gupta, Arun Kumar; Vikram, Naval Kumar

    2015-01-01

    Dengue is a common viral infection worldwide with presentation varying from clinically silent infection to dengue fever, dengue hemorrhagic fever, and severe fulminant dengue shock syndrome. Neurological manifestation usually results from multisystem dysfunction secondary to vascular leak. Presentation as hemorrhagic encephalitis is very rare. Here we present the case of a 13-year-old female admitted with generalized tonic clonic seizures. Plain computed tomography (CT) scan of head revealed hypodensities in bilateral deep gray matter nuclei and right posterior parietal lobe without any hemorrhage. Cerebrospinal fluid (CSF) and serology were positive for IgM and IgG antibodies to dengue viral antigen. Contrast-enhanced magnetic resonance imaging (MRI) revealed multifocal T2 and fluid attenuated inversion recovery (FLAIR) hyperintensities in bilateral cerebral parenchyma including basal ganglia. No hemorrhage was seen. She was managed with steroids. As her clinical condition deteriorated, after being stable for 2 days, repeat MRI was done which revealed development of hemorrhage within the lesions, and diagnosis of acute hemorrhagic encephalitis of dengue viral etiology was made. PMID:25709166

  16. Acute hemorrhagic encephalitis: An unusual presentation of dengue viral infection.

    PubMed

    Nadarajah, Jeyaseelan; Madhusudhan, Kumble Seetharama; Yadav, Ajay Kumar; Gupta, Arun Kumar; Vikram, Naval Kumar

    2015-01-01

    Dengue is a common viral infection worldwide with presentation varying from clinically silent infection to dengue fever, dengue hemorrhagic fever, and severe fulminant dengue shock syndrome. Neurological manifestation usually results from multisystem dysfunction secondary to vascular leak. Presentation as hemorrhagic encephalitis is very rare. Here we present the case of a 13-year-old female admitted with generalized tonic clonic seizures. Plain computed tomography (CT) scan of head revealed hypodensities in bilateral deep gray matter nuclei and right posterior parietal lobe without any hemorrhage. Cerebrospinal fluid (CSF) and serology were positive for IgM and IgG antibodies to dengue viral antigen. Contrast-enhanced magnetic resonance imaging (MRI) revealed multifocal T2 and fluid attenuated inversion recovery (FLAIR) hyperintensities in bilateral cerebral parenchyma including basal ganglia. No hemorrhage was seen. She was managed with steroids. As her clinical condition deteriorated, after being stable for 2 days, repeat MRI was done which revealed development of hemorrhage within the lesions, and diagnosis of acute hemorrhagic encephalitis of dengue viral etiology was made.

  17. Next-generation dengue vaccines: novel strategies currently under development.

    PubMed

    Durbin, Anna P; Whitehead, Stephen S

    2011-10-01

    Dengue has become the most important arboviral infection worldwide with more than 30 million cases of dengue fever estimated to occur each year. The need for a dengue vaccine is great and several live attenuated dengue candidate vaccines are proceeding through clinical evaluation. The need to induce a balanced immune response against all four DENV serotypes with a single vaccine has been a challenge for dengue vaccine developers. A live attenuated DENV chimeric vaccine produced by Sanofi Pasteur has recently entered Phase III evaluation in numerous dengue-endemic regions of the world. Viral interference between serotypes contained in live vaccines has required up to three doses of the vaccine be given over a 12-month period of time. For this reason, novel DENV candidate vaccines are being developed with the goal of achieving a protective immune response with an immunization schedule that can be given over the course of a few months. These next-generation candidates include DNA vaccines, recombinant adenovirus vectored vaccines, alphavirus replicons, and sub-unit protein vaccines. Several of these novel candidates will be discussed.

  18. Dengue Virus Exposures Among Deployed U.S. Military Personnel

    PubMed Central

    Hesse, Elisabeth M.; Martinez, Luis J.; Jarman, Richard G.; Lyons, Arthur G.; Eckels, Kenneth H.; De La Barrera, Rafael A.; Thomas, Stephen J.

    2017-01-01

    Dengue virus infections have adversely impacted U.S. military operations since the Spanish–American War. The erosion of mission capabilities and lost duty days are underestimated. Appreciating the incidence and prevalence of dengue infections in U.S. military personnel is important to inform disease prevention strategies. Banked pre- and post-deployment serum samples from 1,000 U.S. military personnel with a single deployment to a dengue-endemic region were tested using a screening microneutralization assay to detect anti-dengue-virus-neutralizing antibodies. A total of 76 (7.6%) post-deployment samples were positive and 15 of the pre-deployment samples were negative. These figures represent an infection incidence of 1.5% and total of 17.6 seroconversions per 10,000 deployment months. These data represent a deploying military population with a relatively high background rate of dengue seropositivity, a low level of infection during deployment compared with background infection rates in the local populations, and the potential for worsening clinical attack rates with increased frequency of deployment. Additional studies are required to more clearly elucidate the dengue infection and disease risk in U.S. military personnel. PMID:28193746

  19. Economic Cost and Burden of Dengue in the Philippines

    PubMed Central

    Edillo, Frances E.; Halasa, Yara A.; Largo, Francisco M.; Erasmo, Jonathan Neil V.; Amoin, Naomi B.; Alera, Maria Theresa P.; Yoon, In-Kyu; Alcantara, Arturo C.; Shepard, Donald S.

    2015-01-01

    Dengue, the world's most important mosquito-borne viral disease, is endemic in the Philippines. During 2008–2012, the country's Department of Health reported an annual average of 117,065 dengue cases, placing the country fourth in dengue burden in southeast Asia. This study estimates the country's annual number of dengue episodes and their economic cost. Our comparison of cases between active and passive surveillance in Punta Princesa, Cebu City yielded an expansion factor of 7.2, close to the predicted value (7.0) based on the country's health system. We estimated an annual average of 842,867 clinically diagnosed dengue cases, with direct medical costs (in 2012 US dollars) of $345 million ($3.26 per capita). This is 54% higher than an earlier estimate without Philippines-specific costs. Ambulatory settings treated 35% of cases (representing 10% of direct costs), whereas inpatient hospitals served 65% of cases (representing 90% of direct costs). The economic burden of dengue in the Philippines is substantial. PMID:25510723

  20. Economic cost and burden of dengue in the Philippines.

    PubMed

    Edillo, Frances E; Halasa, Yara A; Largo, Francisco M; Erasmo, Jonathan Neil V; Amoin, Naomi B; Alera, Maria Theresa P; Yoon, In-Kyu; Alcantara, Arturo C; Shepard, Donald S

    2015-02-01

    Dengue, the world's most important mosquito-borne viral disease, is endemic in the Philippines. During 2008-2012, the country's Department of Health reported an annual average of 117,065 dengue cases, placing the country fourth in dengue burden in southeast Asia. This study estimates the country's annual number of dengue episodes and their economic cost. Our comparison of cases between active and passive surveillance in Punta Princesa, Cebu City yielded an expansion factor of 7.2, close to the predicted value (7.0) based on the country's health system. We estimated an annual average of 842,867 clinically diagnosed dengue cases, with direct medical costs (in 2012 US dollars) of $345 million ($3.26 per capita). This is 54% higher than an earlier estimate without Philippines-specific costs. Ambulatory settings treated 35% of cases (representing 10% of direct costs), whereas inpatient hospitals served 65% of cases (representing 90% of direct costs). The economic burden of dengue in the Philippines is substantial. © The American Society of Tropical Medicine and Hygiene.