MaHog1, a Hog1-type mitogen-activated protein kinase gene, contributes to stress tolerance and virulence of the entomopathogenic fungus Metarhizium acridum.

PubMed

Jin, Kai; Ming, Yue; Xia, Yu Xian

2012-12-01

Fungal biocontrol agents have great potential in integrated pest management. However, poor efficacy and sensitivity to various adverse factors have hampered their wide application. In eukaryotic cells, Hog1 kinase plays a critical role in stress responses. In this study, MaHog1 (GenBank accession no. EFY85878), encoding a member of the Hog1/Sty1/p38 mitogen-activated protein kinase family in Metarhizium (Me.) acridum, was identified. Targeted gene disruption was used to analyse the role of MaHog1 in virulence and tolerance of adverse factors. Mutants with MaHog1 depletion showed increased sensitivity to high osmotic stress, high temperature and oxidative stress, and exhibited remarkable resistance to cell wall-disturbing agents. These results suggest that Hog1 kinase has a conserved function in regulating multistress responses among fungi, and that MaHog1 might influence cell wall biogenesis in Me. acridum. Bioassays conducted with topical inoculation and intrahaemocoel injection revealed that MaHog1 is required for both penetration and postpenetration development of Me. acridum. MaHog1 disruption resulted in a significant reduction in virulence, likely due to the combination of a decrease in conidial germination, a reduction in appressorium formation and a decline in growth rate in insect haemolymph, which might be caused by impairing fungal tolerance of various stresses during infection.

PCA-HOG symmetrical feature based diseased cell detection

NASA Astrophysics Data System (ADS)

Wan, Min-jie

2016-04-01

A histogram of oriented gradient (HOG) feature is applied to the field of diseased cell detection, which can detect diseased cells in high resolution tissue images rapidly, accurately and efficiently. Firstly, motivated by symmetrical cellular forms, a new HOG symmetrical feature based on the traditional HOG feature is proposed to meet the condition of cell detection. Secondly, considering the high feature dimension of traditional HOG feature leads to plenty of memory resources and long runtime in practical applications, a classical dimension reduction method called principal component analysis (PCA) is used to reduce the dimension of high-dimensional HOG descriptor. Because of that, computational speed is increased greatly, and the accuracy of detection can be controlled in a proper range at the same time. Thirdly, support vector machine (SVM) classifier is trained with PCA-HOG symmetrical features proposed above. At last, practical tissue images is detected and analyzed by SVM classifier. In order to verify the effectiveness of this new algorithm, it is practically applied to conduct diseased cell detection which takes 200 pieces of H&E (hematoxylin & eosin) high resolution staining histopathological images collected from 20 breast cancer patients as a sample. The experiment shows that the average processing rate can be 25 frames per second and the detection accuracy can be 92.1%.

Examination of Salmonella and Escherichia coli translocation from hog manure to forage, soil, and cattle grazed on the hog manure-treated pasture.

PubMed

Holley, Richard; Walkty, Joël; Blank, Gregory; Tenuta, Mario; Ominski, Kimberly; Krause, Denis; Ng, Lai-King

2008-01-01

Use of hog (Sus scrofa) manure as a fertilizer is a practical solution for waste re-utilization, however, it may serve as a vehicle for environmental and domestic animal contamination. Work was conducted to determine whether pathogens, naturally present in hog manure could be detected in cattle (Bos taurus) grazed on the manure-treated pasture, and whether forage contamination occurred. During two 3 mo summer trials manure was applied to yield < or = 124 kg available N per hectare in a single spring or split spring and fall application. Samples of hog manure, forage, soil, and cattle feces were analyzed for naturally occurring Salmonella, Yersinia enterocolitica, and Escherichia coli. To follow movement of Salmonella in the environment isolates were identified to serovar and serotyped. Transfer of E. coli from hog manure to soil and cattle was examined by randomly amplified polymorphic DNA (RAPD) analysis of >600 E. coli isolates. While Y. enterocolitica was absent from all samples, in both years S. enterica Derby and S. enterica Krefeld were found in most hog manure samples, but were only on forage samples in the second year. Salmonella enterica Typhimurium, absent from hog manure was present on some forage in the first year. Cattle feces and soil samples were consistently Salmonella negative. These contaminations could not be traced to manure application. During this study, Salmonella and E. coli found in hog manure had different RAPD genomic profiles from those found in the feces of cattle grazing on manure-treated pasture.

Cholera

PubMed Central

Harris, Jason B.; LaRocque, Regina C.; Qadri, Firdausi; Ryan, Edward T.; Calderwood, Stephen B.

2013-01-01

Summary Cholera is an acute, secretory diarrhea caused by infection with Vibrio cholerae of the O1 and O139 serogroups. Cholera is endemic in over 50 countries and also causes large epidemics. Since 1817, seven cholera pandemics have spread from Asia to much of the world. The 7th pandemic began in 1961 and affects 3–5 million people each year, killing 120,000. Although mild cholera may be indistinguishable from other diarrheal illnesses, the presentation of severe cholera is distinct, with dramatic diarrheal purging. Management of patients with cholera involves aggressive fluid replacement; effective therapy can decrease mortality from over 50% to less than 0.2%. Antibiotics decrease volume and duration of diarrhea by 50% and are recommended for patients with moderate to severe dehydration. Prevention of cholera depends on access to safe water and sanitation. Two oral cholera vaccines are available and the most effective use of these in integrated prevention programs is being actively evaluated. PMID:22748592

Assessing landowners' attitudes toward wild hogs and support for control options.

PubMed

Caplenor, Carlotta A; Poudyal, Neelam C; Muller, Lisa I; Yoest, Chuck

2017-10-01

Wild hogs (Sus scrofa) are an invasive species with destructive habits, particularly rooting and wallowing, which can directly impact agricultural crops, pasture land, and water quality. Considering wild hogs are widely dispersed across the landscape, they are extremely difficult to control. Disagreements can arise among different stakeholders over whether and how their populations should be managed. The purpose of this article was to examine Tennessee, United States landowners' attitudes toward wild hogs, to compare acceptability of control methods, and to evaluate factors significantly influencing public support for regulations to control wild hogs. Logistic regression was employed to analyze data collected from a statewide survey of rural landowners in the fall of 2015. Landowners had overwhelmingly negative attitudes towards wild hogs, and were concerned about their impact on the natural environment and rural economy. Although landowners showed support for controlling wild hogs, levels of acceptability for management options varied. Respondents favored active management and supported education and incentive-based control programs to control wild hogs. Cognitive concepts such as social and personal norms and awareness of consequences, as well as demographic characteristics, significantly predicted landowners' support for state regulations to control wild hogs in Tennessee. Findings increase our understanding of the human dimensions of wild hog management and that of other similarly invasive animals, and may guide resource managers in designing effective and socially acceptable management strategies to control wild hog populations in Tennessee and elsewhere. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cholera.

PubMed

Harris, Jason B; LaRocque, Regina C; Qadri, Firdausi; Ryan, Edward T; Calderwood, Stephen B

2012-06-30

Cholera is an acute, secretory diarrhoea caused by infection with Vibrio cholerae of the O1 or O139 serogroup. It is endemic in more than 50 countries and also causes large epidemics. Since 1817, seven cholera pandemics have spread from Asia to much of the world. The seventh pandemic began in 1961 and affects 3-5 million people each year, killing 120,000. Although mild cholera can be indistinguishable from other diarrhoeal illnesses, the presentation of severe cholera is distinct, with pronounced diarrhoeal purging. Management of patients with cholera involves aggressive fluid replacement; effective therapy can decrease mortality from more than 50% to less than 0·2%. Antibiotic treatment decreases volume and duration of diarrhoea by 50% and is recommended for patients with moderate to severe dehydration. Prevention of cholera depends on access to safe water and sanitation. Two oral cholera vaccines are available and the most effective use of these in integrated prevention programmes is being actively assessed. Copyright © 2012 Elsevier Ltd. All rights reserved.

A method for real-time implementation of HOG feature extraction

NASA Astrophysics Data System (ADS)

Luo, Hai-bo; Yu, Xin-rong; Liu, Hong-mei; Ding, Qing-hai

2011-08-01

Histogram of oriented gradient (HOG) is an efficient feature extraction scheme, and HOG descriptors are feature descriptors which is widely used in computer vision and image processing for the purpose of biometrics, target tracking, automatic target detection(ATD) and automatic target recognition(ATR) etc. However, computation of HOG feature extraction is unsuitable for hardware implementation since it includes complicated operations. In this paper, the optimal design method and theory frame for real-time HOG feature extraction based on FPGA were proposed. The main principle is as follows: firstly, the parallel gradient computing unit circuit based on parallel pipeline structure was designed. Secondly, the calculation of arctangent and square root operation was simplified. Finally, a histogram generator based on parallel pipeline structure was designed to calculate the histogram of each sub-region. Experimental results showed that the HOG extraction can be implemented in a pixel period by these computing units.

Cholera.

PubMed Central

Kaper, J B; Morris, J G; Levine, M M

1995-01-01

Despite more than a century of study, cholera still presents challenges and surprises to us. Throughout most of the 20th century, cholera was caused by Vibrio cholerae of the O1 serogroup and the disease was largely confined to Asia and Africa. However, the last decade of the 20th century has witnessed two major developments in the history of this disease. In 1991, a massive outbreak of cholera started in South America, the one continent previously untouched by cholera in this century. In 1992, an apparently new pandemic caused by a previously unknown serogroup of V. cholerae (O139) began in India and Bangladesh. The O139 epidemic has been occurring in populations assumed to be largely immune to V. cholerae O1 and has rapidly spread to many countries including the United States. In this review, we discuss all aspects of cholera, including the clinical microbiology, epidemiology, pathogenesis, and clinical features of the disease. Special attention will be paid to the extraordinary advances that have been made in recent years in unravelling the molecular pathogenesis of this infection and in the development of new generations of vaccines to prevent it. PMID:7704895

Yeast Hog1 proteins are sequestered in stress granules during high-temperature stress.

PubMed

Shiraishi, Kosuke; Hioki, Takahiro; Habata, Akari; Yurimoto, Hiroya; Sakai, Yasuyoshi

2018-01-09

The yeast high-osmolarity glycerol (HOG) pathway plays a central role in stress responses. It is activated by various stresses, including hyperosmotic stress, oxidative stress, high-temperature stress and exposure to arsenite. Hog1, the crucial MAP kinase of the pathway, localizes to the nucleus in response to high osmotic concentrations, i.e. high osmolarity; but, otherwise, little is known about its intracellular dynamics and regulation. By using the methylotrophic yeast Candida boidinii , we found that CbHog1-Venus formed intracellular dot structures after high-temperature stress in a reversible manner. Microscopic observation revealed that CbHog1-mCherry colocalized with CbPab1-Venus, a marker protein of stress granules. Hog1 homologs in Pichia pastoris and Schizosaccharomyces pombe also exhibited similar dot formation under high-temperature stress, whereas Saccharomyces cerevisiae Hog1 (ScHog1)-GFP did not. Analysis of CbHog1-Venus in C. boidinii revealed that a β-sheet structure in the N-terminal region was necessary and sufficient for its localization to stress granules. Physiological studies revealed that sequestration of activated Hog1 proteins in stress granules was responsible for downregulation of Hog1 activity under high-temperature stress.This article has an associated First Person interview with the first author of the paper. © 2018. Published by The Company of Biologists Ltd.

Production costs and animal welfare for four stylized hog production systems.

PubMed

Seibert, Lacey; Norwood, F Bailey

2011-01-01

Nonhuman animal welfare is arguably the most contentious issue facing the hog industry. Animal advocacy groups influence the regulation of hog farms and induce some consumers to demand more humane pork products. Hog producers are understandably reluctant to improve animal well being unless the premium they extract exceeds the corresponding increase in cost. To better understand the relationship between animal welfare and production costs under different farm systems, this study investigates 4 stylized hog production systems. The results show that increasing animal welfare for all hogs in the United States will increase retail pork prices by a maximum of 2% for a small welfare increase and 5% for a large welfare increase. The cost of banning gestation crates measured by this study is lower than the consumer willingness-to-pay from other studies.

9 CFR 311.24 - Hogs affected with tapeworm cysts.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Hogs affected with tapeworm cysts. 311.24 Section 311.24 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF... affected with tapeworm cysts. Carcasses of hogs affected with tapeworm cysts (Cysticercus cellulosae) may...

9 CFR 311.24 - Hogs affected with tapeworm cysts.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Hogs affected with tapeworm cysts. 311.24 Section 311.24 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF... affected with tapeworm cysts. Carcasses of hogs affected with tapeworm cysts (Cysticercus cellulosae) may...

9 CFR 311.24 - Hogs affected with tapeworm cysts.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Hogs affected with tapeworm cysts. 311.24 Section 311.24 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF... affected with tapeworm cysts. Carcasses of hogs affected with tapeworm cysts (Cysticercus cellulosae) may...

9 CFR 311.24 - Hogs affected with tapeworm cysts.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Hogs affected with tapeworm cysts. 311.24 Section 311.24 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF... affected with tapeworm cysts. Carcasses of hogs affected with tapeworm cysts (Cysticercus cellulosae) may...

9 CFR 311.24 - Hogs affected with tapeworm cysts.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Hogs affected with tapeworm cysts. 311.24 Section 311.24 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF... INSPECTION AND CERTIFICATION DISPOSAL OF DISEASED OR OTHERWISE ADULTERATED CARCASSES AND PARTS § 311.24 Hogs...

Cholera.

PubMed

Lippi, Donatella; Gotuzzo, Eduardo; Caini, Saverio

2016-08-01

Cholera is an acute disease of the gastrointestinal tract caused by Vibrio cholerae. Cholera was localized in Asia until 1817, when a first pandemic spread from India to several other regions of the world. After this appearance, six additional major pandemics occurred during the 19th and 20th centuries, the latest of which originated in Indonesia in the 1960s and is still ongoing. In 1854, a cholera outbreak in Soho, London, was investigated by the English physician John Snow (1813 to 1858). He described the time course of the outbreak, managed to understand its routes of transmission, and suggested effective measures to stop its spread, giving rise to modern infectious disease epidemiology. The germ responsible for cholera was discovered twice: first by the Italian physician Filippo Pacini during an outbreak in Florence, Italy, in 1854, and then independently by Robert Koch in India in 1883, thus favoring the germ theory over the miasma theory of disease. Unlike many other infectious diseases, such as plague, smallpox, and poliomyelitis, cholera persists as a huge public health problem worldwide, even though there are effective methods for its prevention and treatment. The main reasons for its persistence are socioeconomic rather than purely biological; cholera flourishes where there are unsatisfactory hygienic conditions and where a breakdown of already fragile sanitation and health infrastructure occurs because of natural disasters or humanitarian crises.

Cholera Treatment

MedlinePlus

... Travelers Publications, Data, & Statistics Outbreak Response Resources Health Promotion Materials Fact Sheets Posters Videos Training & Education CDC ... improve cholera symptoms in children. Related Pages Health Promotion Materials Cholera Treatment Centers Vaccines Cholera Training and ...

Update: cholera--Western Hemisphere, and recommendations for treatment of cholera.

PubMed

1991-08-16

Epidemic cholera appeared in Peru in January 1991 and subsequently spread to Ecuador, Colombia, Chile, Brazil, Mexico, and Guatemala. Cholera can be a severe, life-threatening illness but is highly preventable and easily treated; however, few health-care practitioners in the United States have experience identifying and treating cholera. This report provides an update on cholera in the Western Hemisphere and provides recommendations on the clinical diagnosis and treatment of cholera in the United States.

THTM: A template matching algorithm based on HOG descriptor and two-stage matching

NASA Astrophysics Data System (ADS)

Jiang, Yuanjie; Ruan, Li; Xiao, Limin; Liu, Xi; Yuan, Feng; Wang, Haitao

2018-04-01

We propose a novel method for template matching named THTM - a template matching algorithm based on HOG (histogram of gradient) and two-stage matching. We rely on the fast construction of HOG and the two-stage matching that jointly lead to a high accuracy approach for matching. TMTM give enough attention on HOG and creatively propose a twice-stage matching while traditional method only matches once. Our contribution is to apply HOG to template matching successfully and present two-stage matching, which is prominent to improve the matching accuracy based on HOG descriptor. We analyze key features of THTM and perform compared to other commonly used alternatives on a challenging real-world datasets. Experiments show that our method outperforms the comparison method.

9 CFR 310.11 - Cleaning of hog carcasses before incising.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Cleaning of hog carcasses before incising. 310.11 Section 310.11 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT... AND VOLUNTARY INSPECTION AND CERTIFICATION POST-MORTEM INSPECTION § 310.11 Cleaning of hog carcasses...

Widespread epidemic cholera caused by a restricted subset of Vibrio cholerae clones.

PubMed

Moore, S; Thomson, N; Mutreja, A; Piarroux, R

2014-05-01

Since 1817, seven cholera pandemics have plagued humankind. As the causative agent, Vibrio cholerae, is autochthonous in the aquatic ecosystem and some studies have revealed links between outbreaks and fluctuations in climatic and aquatic conditions, it has been widely assumed that cholera epidemics are triggered by environmental factors that promote the growth of local bacterial reservoirs. However, mounting epidemiological findings and genome sequence analysis of clinical isolates have indicated that epidemics are largely unassociated with most of the V. cholerae strains in aquatic ecosystems. Instead, only a specific subset of V. cholerae El Tor 'types' appears to be responsible for current epidemics. A recent report examining the evolution of a variety of V. cholerae strains indicates that the current pandemic is monophyletic and originated from a single ancestral clone that has spread globally in successive waves. In this review, we examine the clonal nature of the disease, with the example of the recent history of cholera in the Americas. Epidemiological data and genome sequence-based analysis of V. cholerae isolates demonstrate that the cholera epidemics of the 1990s in South America were triggered by the importation of a pathogenic V. cholerae strain that gradually spread throughout the region until local outbreaks ceased in 2001. Latin America remained almost unaffected by the disease until a new toxigenic V. cholerae clone was imported into Haiti in 2010. Overall, cholera appears to be largely caused by a subset of specific V. cholerae clones rather than by the vast diversity of V. cholerae strains in the environment. © 2014 The Authors Clinical Microbiology and Infection © 2014 European Society of Clinical Microbiology and Infectious Diseases.

Cholera

MedlinePlus

... from cholera. WHO 2016. www.who.int/cholera/technical/en/ . Accessed March 18, 2016. Review Date 3/ ... Duplication for commercial use must be authorized in writing by ADAM Health Solutions. About MedlinePlus Site Map ...

Cholera studies*

PubMed Central

Pollitzer, R.

1957-01-01

Discussing the symptomatology of cholera, the author deals first with the incubation period, the clinical types, choleraic diarrhoea, and cholerine; he then considers in detail the various stages of cholera gravis and the relapses and complications that may be met. This is followed by sections on diagnosis and differential diagnosis, and on prognosis and the various factors influencing it. The author's highly detailed review of the treatment of cholera which concludes this study is divided into three parts, dealing with attempts at specific therapy, with infusion treatment, and with adjuvant treatment. PMID:13426761

Gastrointestinal helminths of wild hogs and their potential livestock and public health significance in Jamaica.

PubMed

Okoro, C K; Wilson, B S; Lorenzo-Morales, J; Robinson, R D

2016-03-01

An investigation into the potential for transmission of gastrointestinal helminths from wild hogs to livestock and humans was prompted by concerns of recreational wild-hog hunting in the Caribbean region and the recent practice, by livestock farmers in Jamaica, of co-rearing wild and domesticated swine. Thirty-one wild hogs from the Hellshire Hills, a dry limestone forest in southern Jamaica, were necropsied during the period June 2004 to August 2006. Thirteen of the captured animals were male and 18 female. Four species of adult helminths were recovered from the gastrointestinal tracts of the wild hogs: Hyostrongylus rubidus (77%), Globocephalus urosubulatus (48%), Oesophagostomum dentatum (42%) and Macroacanthorhynchus hirudinaceus (77%). Two (6.2%), ten (32.2%) and 18 (58.0%) hogs harboured one, two and three species of helminths, respectively. Mean infection intensities varied from 8.1 for M. hirudinaceus, to 115.5 for O. dentatum. There was no association between any of the recovered helminths and sex of the host; however, a multivariate analysis indicated a positive association between the prevalence of G. urosubulatus and host age (odds ratio (OR) = 6.517). Domesticated hogs co-reared with wild hogs are potentially at risk of infection with all four helminths, while wild-hog hunters and pig farmers may be exposed to M. hirudinaceus.

Study of the ubiquitous hog farm system using wireless sensor networks for environmental monitoring and facilities control.

PubMed

Hwang, Jeonghwan; Yoe, Hyun

2010-01-01

Many hog farmers are now suffering from high pig mortality rates due to various wasting diseases and increased breeding costs, etc. It is therefore necessary for hog farms to implement systematic and scientific pig production technology to increase productivity and produce high quality pork in order to solve these problems. In this study, we describe such a technology by suggesting a ubiquitous hog farm system which applies WSN (Wireless Sensor Network) technology to the pig industry. We suggest that a WSN and CCTV (Closed-circuit television) should be installed on hog farms to collect environmental and image information which shall then help producers not only in monitoring the hog farm via the Web from outside the farm, but also facilitate the control of hog farm facilities in remote locations. In addition, facilities can be automatically controlled based on breeding environment parameters which are already set up and a SMS notice service to notify of deviations shall provide users with convenience. Hog farmers may increase production and improve pork quality through this ubiquitous hog farm system and prepare a database with information collected from environmental factors and the hog farm control devices, which is expected to provide information needed to design and implement suitable control strategies for hog farm operation.

Study of the Ubiquitous Hog Farm System Using Wireless Sensor Networks for Environmental Monitoring and Facilities Control

PubMed Central

Hwang, Jeonghwan; Yoe, Hyun

2010-01-01

Many hog farmers are now suffering from high pig mortality rates due to various wasting diseases and increased breeding costs, etc. It is therefore necessary for hog farms to implement systematic and scientific pig production technology to increase productivity and produce high quality pork in order to solve these problems. In this study, we describe such a technology by suggesting a ubiquitous hog farm system which applies WSN (Wireless Sensor Network) technology to the pig industry. We suggest that a WSN and CCTV (Closed-circuit television) should be installed on hog farms to collect environmental and image information which shall then help producers not only in monitoring the hog farm via the Web from outside the farm, but also facilitate the control of hog farm facilities in remote locations. In addition, facilities can be automatically controlled based on breeding environment parameters which are already set up and a SMS notice service to notify of deviations shall provide users with convenience. Hog farmers may increase production and improve pork quality through this ubiquitous hog farm system and prepare a database with information collected from environmental factors and the hog farm control devices, which is expected to provide information needed to design and implement suitable control strategies for hog farm operation. PMID:22163497

Wildlife of southern forests habitat & management (Chapter 16): Wild Hogs

Treesearch

James G. Dickson; John J. Mayer; John D. Dickson

2003-01-01

Wild hogs or swine are medium to large-sized, stout-bodied, and proportionately short-legged hoofed mammals with thick skin covered with sparse to dense coats of coarse bristles. These animals have elongated heads and snouts ending in a disc-like pad through which the external nares open. The only other species in the southern United States that resembles the wild hog...

Cholera: current epidemiology.

PubMed

Crowcroft, N S

1994-12-09

Cholera remains an important cause of morbidity and mortality worldwide. Its epidemiology has changed in the 1990s, with the spread of the seventh pandemic to the western hemisphere and the emergence of a new serogroup, Vibrio cholerae O139. The spread of cholera may be rapid and unpredictable because of aeroplane travel, international shipping, and the migration of people due to war or political unrest. Increasing amounts of largely untreated faeces from growing human populations favour cholera's survival. Most of the world has inadequate sanitation, and future prospects are undermined by the impact of international debt on ailing economies. Furthermore, because cholera is difficult to eradicate from water it is likely to remain a serious threat to public health for some time. Progress is being made in the development of oral vaccines against V. cholerae O1 and serogroup O139.

INTERIOR OF HOG BARN SHOWING MILKING STANCHIONS AND DIAGONAL SHEATHING, ...

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

INTERIOR OF HOG BARN SHOWING MILKING STANCHIONS AND DIAGONAL SHEATHING, LOOKING EAST. (In the 1940s the hog barn was converted to a calf barn to service the growing dairy. After a fire on the property took the Engle’s main barn in 1954, the building was converted into a milking parlor.) - Engle Farm, Barn, 89 South Ebey Road, Coupeville, Island County, WA

Hog-ringer speeds seed trap construction

Treesearch

D.O. Hall

1964-01-01

An upholsterer's hog-ringer, with Hill's No. 1 pig rings, increased production of one-foot-square wire seed traps by 25 percent. A design modification allowed two bottom sections to be cut from a 36-inch roll of wire.

Cholera in Children

MedlinePlus

... Issues Listen Español Text Size Email Print Share Cholera Page Content Article Body Cholera is an infection of the intestines caused by ... that can range from mild to extremely severe. Cholera is rare in the United States but if ...

The Hog1 Mitogen-Activated Protein Kinase Mediates a Hypoxic Response in Saccharomyces cerevisiae

PubMed Central

Hickman, Mark J.; Spatt, Dan; Winston, Fred

2011-01-01

We have studied hypoxic induction of transcription by studying the seripauperin (PAU) genes of Saccharomyces cerevisiae. Previous studies showed that PAU induction requires the depletion of heme and is dependent upon the transcription factor Upc2. We have now identified additional factors required for PAU induction during hypoxia, including Hog1, a mitogen-activated protein kinase (MAPK) whose signaling pathway originates at the membrane. Our results have led to a model in which heme and ergosterol depletion alters membrane fluidity, thereby activating Hog1 for hypoxic induction. Hypoxic activation of Hog1 is distinct from its previously characterized response to osmotic stress, as the two conditions cause different transcriptional consequences. Furthermore, Hog1-dependent hypoxic activation is independent of the S. cerevisiae general stress response. In addition to Hog1, specific components of the SAGA coactivator complex, including Spt20 and Sgf73, are also required for PAU induction. Interestingly, the mammalian ortholog of Spt20, p38IP, has been previously shown to interact with the mammalian ortholog of Hog1, p38. Taken together, our results have uncovered a previously unknown hypoxic-response pathway that may be conserved throughout eukaryotes. PMID:21467572

Assessing hog lagoon waste contamination in the Cape Fear Watershed using Bacteroidetes 16S rRNA gene pyrosequencing.

PubMed

Arfken, Ann M; Song, Bongkeun; Mallin, Michael A

2015-09-01

Hog lagoons can be major sources of waste and nutrient contamination to watersheds adjacent to pig farms. Fecal source tracking methods targeting Bacteroidetes 16S rRNA genes in pig fecal matter may underestimate or fail to detect hog lagoon contamination in riverine environments. In order to detect hog lagoon wastewater contamination in the Cape Fear Watershed, where a large number of hog farms are present, we conducted pyrosequencing analyses of Bacteroidetes 16S rRNA genes in hog lagoon waste and identified new hog lagoon-specific marker sequences. Additional pyrosequencing analyses of Bacteroidetes 16S rRNA genes were conducted with surface water samples collected at 4 sites during 5 months in the Cape Fear Watershed. Using an operational taxonomic unit (OTU) identity cutoff value of 97 %, these newly identified hog lagoon markers were found in 3 of the river samples, while only 1 sample contained the pig fecal marker. In the sample containing the pig fecal marker, there was a relatively high percentage (14.1 %) of the hog lagoon markers and a low pig fecal marker relative abundance of 0.4 % in the Bacteroidetes 16S rRNA gene sequences. This suggests that hog lagoon contamination must be somewhat significant in order for pig fecal markers to be detected, and low levels of hog lagoon contamination cannot be detected targeting only pig-specific fecal markers. Thus, new hog lagoon markers have a better detection capacity for lagoon waste contamination, and in conjunction with a pig fecal marker, provide a more comprehensive and accurate detection of hog lagoon waste contamination in susceptible watersheds.

The global burden of cholera

PubMed Central

Lopez, Anna Lena; You, Young Ae; Kim, Young Eun; Sah, Binod; Maskery, Brian; Clemens, John

2012-01-01

Abstract Objective To estimate the global burden of cholera using population-based incidence data and reports. Methods Countries with a recent history of cholera were classified as endemic or non-endemic, depending on whether they had reported cholera cases in at least three of the five most recent years. The percentages of the population in each country that lacked access to improved sanitation were used to compute the populations at risk for cholera, and incidence rates from published studies were applied to groups of countries to estimate the annual number of cholera cases in endemic countries. The estimates of cholera cases in non-endemic countries were based on the average numbers of cases reported from 2000 to 2008. Literature-based estimates of cholera case-fatality rates (CFRs) were used to compute the variance-weighted average cholera CFRs for estimating the number of cholera deaths. Findings About 1.4 billion people are at risk for cholera in endemic countries. An estimated 2.8 million cholera cases occur annually in such countries (uncertainty range: 1.4–4.3) and an estimated 87 000 cholera cases occur in non-endemic countries. The incidence is estimated to be greatest in children less than 5 years of age. Every year about 91 000 people (uncertainty range: 28 000 to 142 000) die of cholera in endemic countries and 2500 people die of the disease in non-endemic countries. Conclusion The global burden of cholera, as determined through a systematic review with clearly stated assumptions, is high. The findings of this study provide a contemporary basis for planning public health interventions to control cholera. PMID:22461716

Household and Individual Risk Factors for Cholera among Cholera Vaccine Recipients in Rural Haiti.

PubMed

Matias, Wilfredo R; Teng, Jessica E; Hilaire, Isabelle J; Harris, Jason B; Franke, Molly F; Ivers, Louise C

2017-08-01

Oral cholera vaccination was used as part of cholera control in Haiti, but the vaccine does not provide complete protection. We conducted secondary data analyses of a vaccine effectiveness study in Haiti to evaluate risk factors for cholera among cholera vaccine recipients. Individuals vaccinated against cholera that presented with acute watery diarrhea and had a stool sample positive for Vibrio cholerae O1 were included as cases. Up to four vaccinated individuals who did not present for treatment of diarrhea were included as controls for each case, and matched by location of residence, enrollment time, and age. We evaluated sociodemographic characteristics and risk factors for cholera. Univariable and multivariable logistic regression were performed to identify risk factors for cholera among vaccinees. Thirty-three vaccine recipients with culture-confirmed cholera were included as cases. One-hundred-and-seventeen of their matched controls reported receiving vaccine and were included as controls. In a multivariable analysis, self-reporting use of branded household water disinfection products as a means of treating water (adjusted relative risk [aRR] = 44.3, 95% confidence interval [CI] = 4.19-468.05, P = 0.002), and reporting having a latrine as the main household toilet (aRR = 4.22, 95% CI = 1.23-14.43, P = 0.02), were independent risk factors for cholera. Self-reporting always treating water (aRR = 0.09, 95% CI = 0.01-0.57, P = 0.01) was associated with protection against cholera. The field effectiveness of water, sanitation, and hygiene interventions used in combination with cholera vaccination in cholera control should be measured and monitored over time to identify and remediate shortcomings, and ensure successful impact on disease control.

[Cholera in pediatrics].

PubMed

Lezama-Basulto, L A; Mota-Hernández, F

1993-09-01

Cholerae is a grave and acute bacterial intestine infection which is caused by a bacilo, V. cholerae 01, that produces toxic products. Its clinical symptoms range from abundant liquid diarrhoea combined with vomiting and rapid dehydration. It is highly lethal when right treatment is not applied. There are also cases of cholera where victims do not show any symptoms of it, that is asymptomatic carriers. Any clinical suspicion of cholerae has to be corroborated by epidemiological data and its diagnostic confirmation should be done by isolating the bacteria, V. cholerae. When beginning the treatment, it is not necessary to confirm the diagnostic and this is based on the restitution of the liquids lost through vomiting and facing using any methods that are recommended for any other type of diarrhoea. The antimicrobial treatment is used only for grave cases. This present revision includes recent knowledge about cholerae emphasising on the effective management of cases through an adequate use of right treatment methods and also using the principal prevention measures against dissemination of this disease.

Human gait recognition by pyramid of HOG feature on silhouette images

NASA Astrophysics Data System (ADS)

Yang, Guang; Yin, Yafeng; Park, Jeanrok; Man, Hong

2013-03-01

As a uncommon biometric modality, human gait recognition has a great advantage of identify people at a distance without high resolution images. It has attracted much attention in recent years, especially in the fields of computer vision and remote sensing. In this paper, we propose a human gait recognition framework that consists of a reliable background subtraction method followed by the pyramid of Histogram of Gradient (pHOG) feature extraction on the silhouette image, and a Hidden Markov Model (HMM) based classifier. Through background subtraction, the silhouette of human gait in each frame is extracted and normalized from the raw video sequence. After removing the shadow and noise in each region of interest (ROI), pHOG feature is computed on the silhouettes images. Then the pHOG features of each gait class will be used to train a corresponding HMM. In the test stage, pHOG feature will be extracted from each test sequence and used to calculate the posterior probability toward each trained HMM model. Experimental results on the CASIA Gait Dataset B1 demonstrate that with our proposed method can achieve very competitive recognition rate.

Pheromone-Induced Morphogenesis Improves Osmoadaptation Capacity by Activating the HOG MAPK Pathway**

PubMed Central

Baltanás, Rodrigo; Bush, Alan; Couto, Alicia; Durrieu, Lucía; Hohmann, Stefan; Colman-Lerner, Alejandro

2013-01-01

Environmental and internal conditions expose cells to a multiplicity of stimuli whose consequences are difficult to predict. Here, we investigate the response to mating pheromone of yeast cells adapted to high osmolarity. Events downstream of pheromone binding involve two mitogen-activated protein kinase (MAPK) cascades: the pheromone response (PR) and the cell-wall integrity response (CWI). Although these MAPK pathways share components with each and a third MAPK pathway, the high osmolarity response (HOG), they are normally only activated by distinct stimuli, a phenomenon called insulation. We found that in cells adapted to high osmolarity, PR activated the HOG pathway in a pheromone- and osmolarity- dependent manner. Activation of HOG by the PR was not due to loss of insulation, but rather a response to a reduction in internal osmolarity, which resulted from an increase in glycerol release caused by the PR. By analyzing single-cell time courses, we found that stimulation of HOG occurred in discrete bursts that coincided with the “shmooing” morphogenetic process. Activation required the polarisome, the cell wall integrity MAPK Slt2, and the aquaglyceroporin Fps1. HOG activation resulted in high glycerol turnover that improved adaptability to rapid changes in osmolarity. Our work shows how a differentiation signal can recruit a second, unrelated sensory pathway to enable responses to yeast to multiple stimuli. PMID:23612707

Household and Individual Risk Factors for Cholera among Cholera Vaccine Recipients in Rural Haiti

PubMed Central

Matias, Wilfredo R.; Teng, Jessica E.; Hilaire, Isabelle J.; Harris, Jason B.; Franke, Molly F.; Ivers, Louise C.

2017-01-01

Abstract. Oral cholera vaccination was used as part of cholera control in Haiti, but the vaccine does not provide complete protection. We conducted secondary data analyses of a vaccine effectiveness study in Haiti to evaluate risk factors for cholera among cholera vaccine recipients. Individuals vaccinated against cholera that presented with acute watery diarrhea and had a stool sample positive for Vibrio cholerae O1 were included as cases. Up to four vaccinated individuals who did not present for treatment of diarrhea were included as controls for each case, and matched by location of residence, enrollment time, and age. We evaluated sociodemographic characteristics and risk factors for cholera. Univariable and multivariable logistic regression were performed to identify risk factors for cholera among vaccinees. Thirty-three vaccine recipients with culture-confirmed cholera were included as cases. One-hundred-and-seventeen of their matched controls reported receiving vaccine and were included as controls. In a multivariable analysis, self-reporting use of branded household water disinfection products as a means of treating water (adjusted relative risk [aRR] = 44.3, 95% confidence interval [CI] = 4.19–468.05, P = 0.002), and reporting having a latrine as the main household toilet (aRR = 4.22, 95% CI = 1.23–14.43, P = 0.02), were independent risk factors for cholera. Self-reporting always treating water (aRR = 0.09, 95% CI = 0.01–0.57, P = 0.01) was associated with protection against cholera. The field effectiveness of water, sanitation, and hygiene interventions used in combination with cholera vaccination in cholera control should be measured and monitored over time to identify and remediate shortcomings, and ensure successful impact on disease control. PMID:28722575

Feral Hogs Management at Merritt Island National Wildlife Refuge: Analysis of Current Management Program

NASA Technical Reports Server (NTRS)

Rosenfeld, Arie; Hinkle, C. Ross; Epstein, Marc

2002-01-01

This ST1 Technical Memorandum (TM) summarizes a two-month project on feral hog management in Merritt Island National Wildlife Refuge (MINWR). For this project, feral hogs were marked and recaptured, with the help of local trappers, to estimate population size and habitat preferences. Habitat covers included vegetation cover and Light Detection and Ranging (LIDAR) data for MINWR. In addition, an analysis was done of hunting records compiled by the Refuge and hog-car accidents compiled by KSC Security.

Actions of cholera toxin and the prevention and treatment of cholera

NASA Astrophysics Data System (ADS)

Holmgren, Jan

1981-07-01

The drastic intestinal secretion of fluid and electrolytes that is characteristic of cholera is the result of reasonably well understood cellular and biochemical actions of the toxin secreted by Vibrio cholerae. Based on this understanding it is possible to devise new techniques for the treatment and prophylaxis of cholera to complement those based on fluid replacement therapy and sanitation.

Cholera studies*†

PubMed Central

Pollitzer, R.; Burrows, W.

1955-01-01

Relevant information regarding the numerous problems encountered in cholera immunity is dealt with in great detail in this study. Toxin production, bacterial virulence, serological reactions, and the antigenic structure of V. cholerae are discussed. Natural, passive, and active cholera immunity receives special attention, the authors describing the various means of vaccination as well as the evaluation of the immunity induced. PMID:13240451

Cholera Vaccine

MedlinePlus

Why get vaccinated?Cholera is a disease that can cause severe diarrhea and vomiting. If it isn't treated quickly, it can lead ... 130,000 people are thought to die from cholera each year, almost all of them in countries ...

Human Impairment from Living near Confined Animal (Hog) Feeding Operations

PubMed Central

Kilburn, Kaye H.

2012-01-01

Problem. To determine whether neighbors around manure lagoons and massive hog confinement buildings who complained of offensive odors and symptoms had impaired brain and lung functions. Method. We compared near hog manure neighbors of lagoons to people living beyond 3 kilometers in Ohio and to unexposed people controls in a nearby state for neurophysiological, cognitive, recall and memory functions, and pulmonary performance. Results. The 25 exposed subjects averaged 4.3 neurobehavioral abnormalities, significantly different from 2.5 for local controls and 2.3 for Tennessee controls. Exposed subjects mean forced vital capacity and expiratory volume in 1 sec were reduced significantly compared to local and regional controls. Conclusions. Near neighbors of hog enclosures and manure lagoon gases had impaired neurobehavioral functions and pulmonary functions and these effects extended to nearby people thought to be controls. Hydrogen sulfide must be abated because people living near lagoons cannot avoid rotten egg gas. PMID:22496706

Cost-effectiveness of oral cholera vaccine in a stable refugee population at risk for epidemic cholera and in a population with endemic cholera.

PubMed Central

Murray, J.; McFarland, D. A.; Waldman, R. J.

1998-01-01

Recent large epidemics of cholera with high incidence and associated mortality among refugees have raised the question of whether oral cholera vaccines should be considered as an additional preventive measure in high-risk populations. The potential impact of oral cholera vaccines on populations prone to seasonal endemic cholera has also been questioned. This article reviews the potential cost-effectiveness of B-subunit, killed whole-cell (BS-WC) oral cholera vaccine in a stable refugee population and in a population with endemic cholera. In the population at risk for endemic cholera, mass vaccination with BS-WC vaccine is the least cost-effective intervention compared with the provision of safe drinking-water and sanitation or with treatment of the disease. In a refugee population at risk for epidemic disease, the cost-effectiveness of vaccination is similar to that of providing safe drinking-water and sanitation alone, though less cost-effective than treatment alone or treatment combined with the provision of water and sanitation. The implications of these data for public health decision-makers and programme managers are discussed. There is a need for better information on the feasibility and costs of administering oral cholera vaccine in refugee populations and populations with endemic cholera. PMID:9803585

Dynamic processes at stress promoters regulate the bimodal expression of HOG response genes

PubMed Central

2011-01-01

Osmotic stress triggers the activation of the HOG (high osmolarity glycerol) pathway in Saccharomyces cerevisiae. This signaling cascade culminates in the activation of the MAPK (mitogen-activated protein kinase) Hog1. Quantitative single cell measurements revealed a discrepancy between kinase- and transcriptional activities of Hog1. While kinase activity increases proportionally to stress stimulus, gene expression is inhibited under low stress conditions. Interestingly, a slow stochastic gene activation process is responsible for setting a tunable threshold for gene expression under basal or low stress conditions, which generates a bimodal expression pattern at intermediate stress levels. PMID:22446531

Cholera studies*

PubMed Central

Pollitzer, R.

1957-01-01

The first section of this study deals with areas where cholera is endemic and with the conditions normally favouring endemicity. Turning next to epidemics, the author discusses their origin and types, climatic influences on them, their periodicity and the possibility of forecasting them, the role played in them by different serological races of V. cholerae, and the causes of their decline. In a section on the factors governing the local spread of cholera, he considers contact and water-borne infection; the role of contaminated food and drink, of fomites, of flies, and of carriers; and the incidence according to sex, age, race, and occupation. The last part deals with factors governing the spread of cholera over longer distances, and includes discussion of the effect of movements of individuals and groups and of assemblies of the population on pilgrimages or at religious festivals. PMID:13472431

Improving immunization approaches to cholera.

PubMed

Saha, Amit; Rosewell, Alexander; Hayen, Andrew; MacIntyre, C Raina; Qadri, Firdausi

2017-03-01

Cholera's impact is greatest in resource-limited countries. In the last decade several large epidemics have led to a global push to improve and implement the tools for cholera prevention and control. Areas covered: PubMed, Google Scholar and the WHO website were searched to review the literature and summarize the current status of cholera vaccines to make recommendations on improving immunization approaches to cholera. Oral cholera vaccines (OCVs) have demonstrated their effectiveness in endemic, outbreak response and emergency settings, highlighting their potential for wider adoption. While two doses of the currently available OCVs are recommended by manufacturers, a single dose would be easier to implement. Encouragingly, recent studies have shown that cold chain requirements may no longer be essential. The establishment of the global OCV stockpile in 2013 has been a major advance in cholera preparedness. New killed and live-attenuated vaccines are being actively explored as candidate vaccines for endemic settings and/or as a traveller's vaccine. The recent advances in cholera vaccination approaches should be considered in the global cholera control strategy. Expert commentary: The development of affordable cholera vaccines is a major success to improve cholera control. New vaccines and country specific interventions will further reduce the burden of this disease globally.

Targeting the MEF2-Like Transcription Factor Smp1 by the Stress-Activated Hog1 Mitogen-Activated Protein Kinase

PubMed Central

Nadal, Eulàlia de; Casadomé, Laura; Posas, Francesc

2003-01-01

Exposure of Saccharomyces cerevisiae to increases in extracellular osmolarity activates the stress-activated Hog1 mitogen-activated protein kinase (MAPK), which is essential for cell survival upon osmotic stress. Yeast cells respond to osmotic stress by inducing the expression of a very large number of genes, and the Hog1 MAPK plays a critical role in gene transcription upon stress. To understand how Hog1 controls gene expression, we designed a genetic screen to isolate new transcription factors under the control of the MAPK and identified the MEF2-like transcription factor, Smp1, as a target for Hog1. Overexpression of SMP1 induced Hog1-dependent expression of osmoresponsive genes such as STL1, whereas smp1Δ cells were defective in their expression. Consistently, smp1Δ cells displayed reduced viability upon osmotic shock. In vivo coprecipitation and phosphorylation studies showed that Smp1 and Hog1 interact and that Smp1 is phosphorylated upon osmotic stress in a Hog1-dependent manner. Hog1 phosphorylated Smp1 in vitro at the C-terminal region. Phosphorylation of Smp1 by the MAPK is essential for its function, since a mutant allele unable to be phosphorylated by the MAPK displays impaired stress responses. Thus, our data indicate that Smp1 acts downstream of Hog1, controlling a subset of the responses induced by the MAPK. Moreover, Smp1 concentrates in the nucleus during the stationary phase, and the lack of SMP1 results in cells that lose viability in the stationary phase. Localization of Smp1 depends on HOG1, and consistently, hog1Δ cells also lose viability during this growth phase. These data suggest that Smp1 could be mediating a role for the Hog1 MAPK during the stationary phase. PMID:12482976

Identifying cholera "hotspots" in Uganda: An analysis of cholera surveillance data from 2011 to 2016

PubMed Central

Bwire, Godfrey; Sack, David A.; Nakinsige, Anne; Naigaga, Martha; Debes, Amanda K.; Ngwa, Moise C.; Brooks, W. Abdullah; Garimoi Orach, Christopher

2017-01-01

Background Despite advance in science and technology for prevention, detection and treatment of cholera, this infectious disease remains a major public health problem in many countries in sub-Saharan Africa, Uganda inclusive. The aim of this study was to identify cholera hotspots in Uganda to guide the development of a roadmap for prevention, control and elimination of cholera in the country. Methodology/Principle findings We obtained district level confirmed cholera outbreak data from 2011 to 2016 from the Ministry of Health, Uganda. Population and rainfall data were obtained from the Uganda Bureau of Statistics, and water, sanitation and hygiene data from the Ministry of Water and Environment. A spatial scan test was performed to identify the significantly high risk clusters. Cholera hotspots were defined as districts whose center fell within a significantly high risk cluster or where a significantly high risk cluster was completely superimposed onto a district. A zero-inflated negative binomial regression model was employed to identify the district level risk factors for cholera. In total 11,030 cases of cholera were reported during the 6-year period. 37(33%) of 112 districts reported cholera outbreaks in one of the six years, and 20 (18%) districts experienced cholera at least twice in those years. We identified 22 districts as high risk for cholera, of which 13 were near a border of Democratic Republic of Congo (DRC), while 9 districts were near a border of Kenya. The relative risk of having cholera inside the high-risk districts (hotspots) were 2 to 22 times higher than elsewhere in the country. In total, 7 million people were within cholera hotspots. The negative binomial component of the ZINB model shows people living near a lake or the Nile river were at increased risk for cholera (incidence rate ratio, IRR = 0.98, 95% CI: 0.97 to 0.99, p < .01); people living near the border of DRC/Kenya or higher incidence rate in the neighboring districts were increased

Identifying cholera "hotspots" in Uganda: An analysis of cholera surveillance data from 2011 to 2016.

PubMed

Bwire, Godfrey; Ali, Mohammad; Sack, David A; Nakinsige, Anne; Naigaga, Martha; Debes, Amanda K; Ngwa, Moise C; Brooks, W Abdullah; Garimoi Orach, Christopher

2017-12-01

Despite advance in science and technology for prevention, detection and treatment of cholera, this infectious disease remains a major public health problem in many countries in sub-Saharan Africa, Uganda inclusive. The aim of this study was to identify cholera hotspots in Uganda to guide the development of a roadmap for prevention, control and elimination of cholera in the country. We obtained district level confirmed cholera outbreak data from 2011 to 2016 from the Ministry of Health, Uganda. Population and rainfall data were obtained from the Uganda Bureau of Statistics, and water, sanitation and hygiene data from the Ministry of Water and Environment. A spatial scan test was performed to identify the significantly high risk clusters. Cholera hotspots were defined as districts whose center fell within a significantly high risk cluster or where a significantly high risk cluster was completely superimposed onto a district. A zero-inflated negative binomial regression model was employed to identify the district level risk factors for cholera. In total 11,030 cases of cholera were reported during the 6-year period. 37(33%) of 112 districts reported cholera outbreaks in one of the six years, and 20 (18%) districts experienced cholera at least twice in those years. We identified 22 districts as high risk for cholera, of which 13 were near a border of Democratic Republic of Congo (DRC), while 9 districts were near a border of Kenya. The relative risk of having cholera inside the high-risk districts (hotspots) were 2 to 22 times higher than elsewhere in the country. In total, 7 million people were within cholera hotspots. The negative binomial component of the ZINB model shows people living near a lake or the Nile river were at increased risk for cholera (incidence rate ratio, IRR = 0.98, 95% CI: 0.97 to 0.99, p < .01); people living near the border of DRC/Kenya or higher incidence rate in the neighboring districts were increased risk for cholera in a district (IRR = 0

Impact of oral cholera vaccines in cholera-endemic countries: A mathematical modeling study.

PubMed

Kim, Jong-Hoon; Mogasale, Vittal; Burgess, Colleen; Wierzba, Thomas F

2016-04-19

Impact evaluation of vaccination programs is necessary for making decisions to introduce oral cholera vaccines (OCVs) in cholera-endemic countries. We analyzed data to forecast the future global burden of cholera. We developed a mathematical model of cholera transmission in three countries as examples: Nigeria, Uganda, and Indonesia. After fitting the model, we evaluated the impact of OCVs delivered in four vaccination strategies varying by target age group and frequency of vaccination over the period of 2015-2030. Data suggest that the global annual incidence of cholera will increase from 3046238 in 2015 to 3787385 in 2030 with the highest burden in Asia and Africa where overall population size is large and the proportion of population with access to improved sanitation facilities is low. We estimate that OCV will reduce the cumulative incidence of cholera by half in Indonesia and >80% in Nigeria and Uganda when delivered to 1+ year olds every three years at a coverage rate of 50%, although cholera may persist through higher coverage rates (i.e., >90%). The proportion of person-to-person transmission compared to water-to-person transmission is positively correlated with higher vaccination impact in all three countries. Periodic OCV vaccination every three or five years can significantly reduce the global burden of cholera although cholera may persist even with high OCV coverage. Vaccination impact will likely vary depending on local epidemiological conditions including age distribution of cases and relative contribution of different transmission routes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cholera outbreaks in Africa.

PubMed

Mengel, Martin A; Delrieu, Isabelle; Heyerdahl, Leonard; Gessner, Bradford D

2014-01-01

During the current seventh cholera pandemic, Africa bore the major brunt of global disease burden. More than 40 years after its resurgence in Africa in 1970, cholera remains a grave public health problem, characterized by large disease burden, frequent outbreaks, persistent endemicity, and high CFRs, particularly in the region of the central African Great Lakes which might act as reservoirs for cholera. There, cases occur year round with a rise in incidence during the rainy season. Elsewhere in sub-Saharan Africa, cholera occurs mostly in outbreaks of varying size with a constant threat of widespread epidemics. Between 1970 and 2011, African countries reported 3,221,050 suspected cholera cases to the World Health Organization, representing 46 % of all cases reported globally. Excluding the Haitian epidemic, sub-Saharan Africa accounted for 86 % of reported cases and 99 % of deaths worldwide in 2011. The number of cholera cases is possibly much higher than what is reported to the WHO due to the variation in modalities, completeness, and case definition of national cholera data. One source on country specific incidence rates for Africa, adjusting for underreporting, estimates 1,341,080 cases and 160,930 deaths (52.6 % of 2,548,227 estimated cases and 79.6 % of 209,216 estimated deaths worldwide). Another estimates 1,411,453 cases and 53,632 deaths per year, respectively (50 % of 2,836,669 estimated cases and 58.6 % of 91,490 estimated deaths worldwide). Within Africa, half of all cases between 1970 and 2011 were notified from only seven countries: Angola, Democratic Republic of the Congo, Mozambique, Nigeria, Somalia, Tanzania, and South Africa. In contrast to a global trend of decreasing case fatality ratios (CFRs), CFRs have remained stable in Africa at approximately 2 %. Early propagation of cholera outbreaks depends largely on the extent of individual bacterial shedding, host and organism characteristics, the likelihood of people coming into contact with

Cholera studies*†

PubMed Central

Pollitzer, R.

1955-01-01

In this study, the author describes in detail experimental cholera infection of mammals (infection by the oral route, intragastric inoculation, and intestinal, gall-bladder, and parenteral infection). The pathogenicity for lower animals is examined, and certain observations on insects are included. The second part of the study is devoted to the pathology of human cholera (morbid anatomy distribution of the causative organisms in the dead bodies of cholera victims, and pathogenesis). PMID:13284569

Cholera: foodborne transmission and its prevention.

PubMed

Estrada-García, T; Mintz, E D

1996-10-01

The last several years have witnessed a tremendous increase in reported cholera cases across the globe. The explosive arrival of the seventh cholera pandemic in Latin American in 1991, dramatic epidemics of cholera on the Indian subcontinent and in Southeast Asia due to the newly recognized Vibrio cholerae O139 strain, and the often deadly presence of cholera among populations affected by political and social upheaval in Africa and Eastern Europe are evidence that many countries have failed to adopt effective measures for cholera prevention and control. Foodborne transmission of cholera has been well documented by epidemiologic investigations in nearly every continent, and its interruption is a critical component to any integrated programme for cholera prevention and control. We emphasize clear and effective guidelines for the prevention of foodborne cholera transmission that are drawn from a comprehensive review of relevant epidemiologic and laboratory data.

Cholera in the 21st century.

PubMed

Charles, Richelle C; Ryan, Edward T

2011-10-01

This review will focus on recent advances in our understanding of biologic and environmental factors that shape current cholera outbreaks, advances in our understanding of host-pathogen interactions during cholera, and recent evolution of current treatment and cholera prevention strategies. New research studies have improved our understanding of a number of dynamic factors that shape the ecology of Vibrio cholerae and influence its transmission, including the role of lytic bacteriophage, biofilm formation, a hyperinfectious state of human-passaged V. cholerae, and the impact of severe weather events. Provision of safe water and improved sanitation continue to be the mainstays of preventing cholera transmission; however, the role of cholera vaccination as a control measure in both endemic and epidemic settings is evolving. Recent advances in our understanding of long-lived protective immunity after natural infection may aid in the global efforts to control cholera. Improved understanding of factors associated with protective immunity and dynamic factors associated with cholera outbreaks may lead to improved control and prevention strategies for cholera.

Opposing PKA and Hog1 signals control the post-transcriptional response to glucose availability in Cryptococcus neoformans.

PubMed

Banerjee, Dithi; Bloom, Amanda L M; Panepinto, John C

2016-10-01

The pathogenic fungus Cryptococcus neoformans must adapt to glucose-limited conditions in the lung and glucose replete conditions upon dissemination to the brain. We report that glucose controls ribosome biogenesis and translation by modulating mRNA decay through a balance of PKA and Hog1 signalling. Glucose signalling through PKA stabilized ribosomal protein (RP) mRNAs whereas glucose starvation destabilized RP transcripts through Hog1. Glucose starvation-induced oxidative stress response genes, and treatment of glucose-fed cells with reactive oxygen species (ROS) generating compounds repressed RP transcripts, both of which were dependent on Hog1. Stabilization of RP transcripts led to retention of polysomes in a hog1Δ mutant, whereas stabilization of RP transcripts by cyclic AMP did not affect translation repression, suggesting that Hog1 alone signals translation repression. In sum, this work describes a novel antagonism between PKA and Hog1 controlling ribosome biogenesis via mRNA stability in response to glucose availability in this important human pathogen. © 2016 John Wiley & Sons Ltd.

Promotion of Cholera Awareness among Households of Cholera Patients: A Randomized Controlled Trial of the Cholera-Hospital-Based-Intervention-for-7 Days (CHoBI7) Intervention

PubMed Central

Saif-Ur-Rahman, K. M.; Parvin, Tahmina; Bhuyian, Sazzadul Islam; Zohura, Fatema; Begum, Farzana; Rashid, Mahamud-Ur; Biswas, Shwapon Kumar; Sack, David; Sack, R. Bradley; Monira, Shirajum; Alam, Munirul; Shaly, Nusrat Jahan; George, Christine Marie

2016-01-01

Previous studies have demonstrated that household contacts of cholera patients are highly susceptible to cholera infections for a 7-day period after the presentation of the index patient in the hospital. However, there is no standard of care to prevent cholera transmission in this high-risk population. Furthermore, there is limited information available on awareness of cholera transmission and prevention among cholera patients and their household contacts. To initiate a standard of care for this high-risk population, we developed the Cholera-Hospital-Based-Intervention-for-7-Days (CHoBI7), which delivers a handwashing with soap and water treatment intervention to household contacts during the time they spend with the admitted cholera patient in the hospital and reinforces these messages through home visits. To test CHoBI7, we conducted a randomized controlled trial among 302 intervention cholera patient household members and 302 control cholera patient household members in Dhaka, Bangladesh. In this study, we evaluated the effectiveness of the CHoBI7 intervention in increasing awareness of cholera transmission and prevention, and the key times for handwashing with soap. We observed a significant increase in cholera knowledge score in the intervention arm compared with the control arm at both the 1-week follow-up {score coefficient = 2.34 (95% confidence interval [CI] = 1.96, 2.71)} and 6 to 12-month follow-up period (score coefficient = 1.59 [95% CI = 1.05, 2.13]). This 1-week hospital- and home-based intervention led to a significant increase in knowledge of cholera transmission and prevention which was sustained 6 to 12 months post-intervention. These findings suggest that the CHoBI7 intervention presents a promising approach to increase cholera awareness among this high-risk population. PMID:27799644

Promotion of Cholera Awareness Among Households of Cholera Patients: A Randomized Controlled Trial of the Cholera-Hospital-Based-Intervention-for-7 Days (CHoBI7) Intervention.

PubMed

Saif-Ur-Rahman, K M; Parvin, Tahmina; Bhuyian, Sazzadul Islam; Zohura, Fatema; Begum, Farzana; Rashid, Mahamud-Ur; Biswas, Shwapon Kumar; Sack, David; Sack, R Bradley; Monira, Shirajum; Alam, Munirul; Shaly, Nusrat Jahan; George, Christine Marie

2016-12-07

Previous studies have demonstrated that household contacts of cholera patients are highly susceptible to cholera infections for a 7-day period after the presentation of the index patient in the hospital. However, there is no standard of care to prevent cholera transmission in this high-risk population. Furthermore, there is limited information available on awareness of cholera transmission and prevention among cholera patients and their household contacts. To initiate a standard of care for this high-risk population, we developed the Cholera-Hospital-Based-Intervention-for-7-Days (CHoBI7), which delivers a handwashing with soap and water treatment intervention to household contacts during the time they spend with the admitted cholera patient in the hospital and reinforces these messages through home visits. To test CHoBI7, we conducted a randomized controlled trial among 302 intervention cholera patient household members and 302 control cholera patient household members in Dhaka, Bangladesh. In this study, we evaluated the effectiveness of the CHoBI7 intervention in increasing awareness of cholera transmission and prevention, and the key times for handwashing with soap. We observed a significant increase in cholera knowledge score in the intervention arm compared with the control arm at both the 1-week follow-up {score coefficient = 2.34 (95% confidence interval [CI] = 1.96, 2.71)} and 6 to 12-month follow-up period (score coefficient = 1.59 [95% CI = 1.05, 2.13]). This 1-week hospital- and home-based intervention led to a significant increase in knowledge of cholera transmission and prevention which was sustained 6 to 12 months post-intervention. These findings suggest that the CHoBI7 intervention presents a promising approach to increase cholera awareness among this high-risk population. © The American Society of Tropical Medicine and Hygiene.

Cholera - management and prevention.

PubMed

Davies, Hannah G; Bowman, Conor; Luby, Stephen P

2017-06-01

Cholera is an acute secretory diarrhoeal infection caused by the bacterium Vibrio cholerae. It is likely to have originated in the Indian sub-continent; however, it spread to cause six worldwide pandemics between 1817-1923. The ongoing seventh worldwide pandemic of cholera began in 1961. The intensity, duration and severity of cholera epidemics have been increasing, signaling the need for more effective control and prevention measures. The response to the cholera pandemics of the 19th century led to the development of safe and effective sanitation and water systems which have effectively removed the risk of cholera in many settings. However, such systems are not in place to protect billions of people worldwide. Although some progress has been made in expanding access to water in recent years, achieving optimal infrastructure will, in the most optimistic scenario, take decades. Climate change, extreme weather events and rapid urbanisation suggests that alternatives to the current paradigm of providing large centralised water and sanitation systems should be considered, including smaller decentralised systems. The aim of this review paper is to provide an overview of current knowledge regarding management of cholera with a focus on prevention measures including vaccination and water and sanitation interventions. © 2017 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

Phylogenetic Diversity of Vibrio cholerae Associated with Endemic Cholera in Mexico from 1991 to 2008.

PubMed

Choi, Seon Young; Rashed, Shah M; Hasan, Nur A; Alam, Munirul; Islam, Tarequl; Sadique, Abdus; Johura, Fatema-Tuz; Eppinger, Mark; Ravel, Jacques; Huq, Anwar; Cravioto, Alejandro; Colwell, Rita R

2016-03-15

An outbreak of cholera occurred in 1991 in Mexico, where it had not been reported for more than a century and is now endemic. Vibrio cholerae O1 prototype El Tor and classical strains coexist with altered El Tor strains (1991 to 1997). Nontoxigenic (CTX(-)) V. cholerae El Tor dominated toxigenic (CTX(+)) strains (2001 to 2003), but V. cholerae CTX(+) variant El Tor was isolated during 2004 to 2008, outcompeting CTX(-) V. cholerae. Genomes of six Mexican V. cholerae O1 strains isolated during 1991 to 2008 were sequenced and compared with both contemporary and archived strains of V. cholerae. Three were CTX(+) El Tor, two were CTX(-) El Tor, and the remaining strain was a CTX(+) classical isolate. Whole-genome sequence analysis showed the six isolates belonged to five distinct phylogenetic clades. One CTX(-) isolate is ancestral to the 6th and 7th pandemic CTX(+) V. cholerae isolates. The other CTX(-) isolate joined with CTX(-) non-O1/O139 isolates from Haiti and seroconverted O1 isolates from Brazil and Amazonia. One CTX(+) isolate was phylogenetically placed with the sixth pandemic classical clade and the V. cholerae O395 classical reference strain. Two CTX(+) El Tor isolates possessing intact Vibrio seventh pandemic island II (VSP-II) are related to hybrid El Tor isolates from Mozambique and Bangladesh. The third CTX(+) El Tor isolate contained West African-South American (WASA) recombination in VSP-II and showed relatedness to isolates from Peru and Brazil. Except for one isolate, all Mexican isolates lack SXT/R391 integrative conjugative elements (ICEs) and sensitivity to selected antibiotics, with one isolate resistant to streptomycin. No isolates were related to contemporary isolates from Asia, Africa, or Haiti, indicating phylogenetic diversity. Sequencing of genomes of V. cholerae is critical if genetic changes occurring over time in the circulating population of an area of endemicity are to be understood. Although cholera outbreaks occurred rarely

Fish as Hosts of Vibrio cholerae.

PubMed

Halpern, Malka; Izhaki, Ido

2017-01-01

Vibrio cholerae , the causative agent of pandemic cholera, is abundant in marine and freshwater environments. Copepods and chironomids are natural reservoirs of this species. However, the ways V. cholerae is globally disseminated are as yet unknown. Here we review the scientific literature that provides evidence for the possibility that some fish species may be reservoirs and vectors of V. cholerae . So far, V. cholerae has been isolated from 30 fish species (22 freshwater; 9 marine). V. cholerae O1 was reported in a few cases. In most cases V. cholerae was isolated from fish intestines, but it has also been detected in gills, skin, kidney, liver and brain tissue. In most cases the fish were healthy but in some, they were diseased. Nevertheless, Koch postulates were not applied to prove that V. cholerae and not another agent was the cause of the disease in the fish. Evidence from the literature correlates raw fish consumption or fish handling to a few cholera cases or cholera epidemics. Thus, we can conclude that V. cholerae inhabits some marine and freshwater fish species. It is possible that fish may protect the bacteria in unfavorable habitats while the bacteria may assist the fish to digest its food. Also, fish may disseminate the bacteria in the aquatic environment and may transfer it to waterbirds that consume them. Thus, fish are reservoirs of V. cholerae and may play a role in its global dissemination.

Fish as Hosts of Vibrio cholerae

PubMed Central

Halpern, Malka; Izhaki, Ido

2017-01-01

Vibrio cholerae, the causative agent of pandemic cholera, is abundant in marine and freshwater environments. Copepods and chironomids are natural reservoirs of this species. However, the ways V. cholerae is globally disseminated are as yet unknown. Here we review the scientific literature that provides evidence for the possibility that some fish species may be reservoirs and vectors of V. cholerae. So far, V. cholerae has been isolated from 30 fish species (22 freshwater; 9 marine). V. cholerae O1 was reported in a few cases. In most cases V. cholerae was isolated from fish intestines, but it has also been detected in gills, skin, kidney, liver and brain tissue. In most cases the fish were healthy but in some, they were diseased. Nevertheless, Koch postulates were not applied to prove that V. cholerae and not another agent was the cause of the disease in the fish. Evidence from the literature correlates raw fish consumption or fish handling to a few cholera cases or cholera epidemics. Thus, we can conclude that V. cholerae inhabits some marine and freshwater fish species. It is possible that fish may protect the bacteria in unfavorable habitats while the bacteria may assist the fish to digest its food. Also, fish may disseminate the bacteria in the aquatic environment and may transfer it to waterbirds that consume them. Thus, fish are reservoirs of V. cholerae and may play a role in its global dissemination. PMID:28293221

Cholera in Brest, France.

PubMed

Pougnet, Laurence; Pougnet, Richard; Voarino, Audrey; Sapin, Jeanne; Drouillard, Isabelle; Quilici, Marie Laure; Désidéri-Vaillant, Catherine

2018-01-01

This is a case report about a 54-year-old man with hypovolemic shock, due to diarrhea and major vomiting after his return from India. The isolation of Vibrio cholerae serogroup O1 (Ogawa serotype) explains this typical clinical presentation of cholera, seen in 10% of cholera cases only. The patient had co-infection with Vibrio cholerae and Campylobacter coli. Co-infections appear to be frequent in endemic areas. The purpose of this case report is to recall the relevance of Vibrio isolation when the clinical context is evocative (diarrhea on travel return, raw sea food consumption).

9 CFR 319.144 - Whole hog sausage.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Whole hog sausage. 319.144 Section 319.144 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... CERTIFICATION DEFINITIONS AND STANDARDS OF IDENTITY OR COMPOSITION Sausage Generally: Fresh Sausage § 319.144...

9 CFR 319.144 - Whole hog sausage.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Whole hog sausage. 319.144 Section 319.144 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... CERTIFICATION DEFINITIONS AND STANDARDS OF IDENTITY OR COMPOSITION Sausage Generally: Fresh Sausage § 319.144...

A Hybrid Vehicle Detection Method Based on Viola-Jones and HOG + SVM from UAV Images

PubMed Central

Xu, Yongzheng; Yu, Guizhen; Wang, Yunpeng; Wu, Xinkai; Ma, Yalong

2016-01-01

A new hybrid vehicle detection scheme which integrates the Viola-Jones (V-J) and linear SVM classifier with HOG feature (HOG + SVM) methods is proposed for vehicle detection from low-altitude unmanned aerial vehicle (UAV) images. As both V-J and HOG + SVM are sensitive to on-road vehicles’ in-plane rotation, the proposed scheme first adopts a roadway orientation adjustment method, which rotates each UAV image to align the roads with the horizontal direction so the original V-J or HOG + SVM method can be directly applied to achieve fast detection and high accuracy. To address the issue of descending detection speed for V-J and HOG + SVM, the proposed scheme further develops an adaptive switching strategy which sophistically integrates V-J and HOG + SVM methods based on their different descending trends of detection speed to improve detection efficiency. A comprehensive evaluation shows that the switching strategy, combined with the road orientation adjustment method, can significantly improve the efficiency and effectiveness of the vehicle detection from UAV images. The results also show that the proposed vehicle detection method is competitive compared with other existing vehicle detection methods. Furthermore, since the proposed vehicle detection method can be performed on videos captured from moving UAV platforms without the need of image registration or additional road database, it has great potentials of field applications. Future research will be focusing on expanding the current method for detecting other transportation modes such as buses, trucks, motors, bicycles, and pedestrians. PMID:27548179

A Hybrid Vehicle Detection Method Based on Viola-Jones and HOG + SVM from UAV Images.

PubMed

Xu, Yongzheng; Yu, Guizhen; Wang, Yunpeng; Wu, Xinkai; Ma, Yalong

2016-08-19

A new hybrid vehicle detection scheme which integrates the Viola-Jones (V-J) and linear SVM classifier with HOG feature (HOG + SVM) methods is proposed for vehicle detection from low-altitude unmanned aerial vehicle (UAV) images. As both V-J and HOG + SVM are sensitive to on-road vehicles' in-plane rotation, the proposed scheme first adopts a roadway orientation adjustment method, which rotates each UAV image to align the roads with the horizontal direction so the original V-J or HOG + SVM method can be directly applied to achieve fast detection and high accuracy. To address the issue of descending detection speed for V-J and HOG + SVM, the proposed scheme further develops an adaptive switching strategy which sophistically integrates V-J and HOG + SVM methods based on their different descending trends of detection speed to improve detection efficiency. A comprehensive evaluation shows that the switching strategy, combined with the road orientation adjustment method, can significantly improve the efficiency and effectiveness of the vehicle detection from UAV images. The results also show that the proposed vehicle detection method is competitive compared with other existing vehicle detection methods. Furthermore, since the proposed vehicle detection method can be performed on videos captured from moving UAV platforms without the need of image registration or additional road database, it has great potentials of field applications. Future research will be focusing on expanding the current method for detecting other transportation modes such as buses, trucks, motors, bicycles, and pedestrians.

Knowledge, Attitudes, and Practices regarding Diarrhea and Cholera following an Oral Cholera Vaccination Campaign in the Solomon Islands

PubMed Central

Burnett, Eleanor; Dalipanda, Tenneth; Ogaoga, Divi; Gaiofa, Jenny; Jilini, Gregory; Halpin, Alison; Dietz, Vance; Date, Kashmira; Mintz, Eric; Hyde, Terri; Wannemuehler, Kathleen; Yen, Catherine

2016-01-01

Background In response to a 2011 cholera outbreak in Papua New Guinea, the Government of the Solomon Islands initiated a cholera prevention program which included cholera disease prevention and treatment messaging, community meetings, and a pre-emptive cholera vaccination campaign targeting 11,000 children aged 1–15 years in selected communities in Choiseul and Western Provinces. Methodology and Principal Findings We conducted a post-vaccination campaign, household-level survey about knowledge, attitudes, and practices regarding diarrhea and cholera in areas targeted and not targeted for cholera vaccination. Respondents in vaccinated areas were more likely to have received cholera education in the previous 6 months (33% v. 9%; p = 0.04), to know signs and symptoms (64% vs. 22%; p = 0.02) and treatment (96% vs. 50%; p = 0.02) of cholera, and to be aware of cholera vaccine (48% vs. 14%; p = 0.02). There were no differences in water, sanitation, and hygiene practices. Conclusions This pre-emptive OCV campaign in a cholera-naïve community provided a unique opportunity to assess household-level knowledge, attitudes, and practices regarding diarrhea, cholera, and water, sanitation, and hygiene (WASH). Our findings suggest that education provided during the vaccination campaign may have reinforced earlier mass messaging about cholera and diarrheal disease in vaccinated communities. PMID:27548678

Knowledge, Attitudes, and Practices regarding Diarrhea and Cholera following an Oral Cholera Vaccination Campaign in the Solomon Islands.

PubMed

Burnett, Eleanor; Dalipanda, Tenneth; Ogaoga, Divi; Gaiofa, Jenny; Jilini, Gregory; Halpin, Alison; Dietz, Vance; Date, Kashmira; Mintz, Eric; Hyde, Terri; Wannemuehler, Kathleen; Yen, Catherine

2016-08-01

In response to a 2011 cholera outbreak in Papua New Guinea, the Government of the Solomon Islands initiated a cholera prevention program which included cholera disease prevention and treatment messaging, community meetings, and a pre-emptive cholera vaccination campaign targeting 11,000 children aged 1-15 years in selected communities in Choiseul and Western Provinces. We conducted a post-vaccination campaign, household-level survey about knowledge, attitudes, and practices regarding diarrhea and cholera in areas targeted and not targeted for cholera vaccination. Respondents in vaccinated areas were more likely to have received cholera education in the previous 6 months (33% v. 9%; p = 0.04), to know signs and symptoms (64% vs. 22%; p = 0.02) and treatment (96% vs. 50%; p = 0.02) of cholera, and to be aware of cholera vaccine (48% vs. 14%; p = 0.02). There were no differences in water, sanitation, and hygiene practices. This pre-emptive OCV campaign in a cholera-naïve community provided a unique opportunity to assess household-level knowledge, attitudes, and practices regarding diarrhea, cholera, and water, sanitation, and hygiene (WASH). Our findings suggest that education provided during the vaccination campaign may have reinforced earlier mass messaging about cholera and diarrheal disease in vaccinated communities.

9 CFR 311.22 - Hogs affected with urticaria, tinea tonsurans, demodex follicurlorum, or erythema.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Hogs affected with urticaria, tinea tonsurans, demodex follicurlorum, or erythema. 311.22 Section 311.22 Animals and Animal Products FOOD SAFETY... OTHERWISE ADULTERATED CARCASSES AND PARTS § 311.22 Hogs affected with urticaria, tinea tonsurans, demodex...

Involvement of the mitogen activated protein kinase Hog1p in the response of Candida albicans to iron availability

PubMed Central

2013-01-01

Background Iron is an essential nutrient for almost all organisms, and generating iron limiting conditions for pathogens is one of the host defense strategies against microbial infections. Excess of iron can be toxic; therefore, iron uptake is tightly controlled. The high affinity iron uptake system of the opportunistic pathogenic yeast Candida albicans has been shown to be essential for virulence. Several transcription factors and regulators of iron uptake genes were identified, but the knowledge of signaling pathways is still limited. Gene expression profiling of the Δhog1 deletion mutant indicated an involvement of the mitogen activated protein (MAP) kinase Hog1p. However, the function of Hog1p in the response of C. albicans to iron availability was not studied in detail. Thus, we analyzed phenotypic and molecular responses of C. albicans to different iron concentrations particularly with respect to the activity of the Hog1p MAP kinase module. Results We observed flocculation of yeast cells, when the iron ion concentration was equal to or higher than 5 μM. This phenotype was dependent on the MAP kinase Hog1p and the corresponding MAP kinase kinase Pbs2p. Moreover, high extracellular iron ion concentrations led to hyper-phosphorylation of Hog1p. We determined lower amounts of multicopper ferroxidase (MCFO) proteins and lower ferric reductase activity, when the iron ion concentration in the medium was increased. This effect was also observed for the Δhog1 mutant. However, the amounts of MCFO proteins and the cell surface ferric reductase activity were increased in the Δhog1 in comparison to wild type cells. This effect was independent of iron availability in growth media. Conclusions In C. albicans, the MAP kinase Hog1p is part of the network regulating the response of the organism to iron availability. Hog1p was transiently phosphorylated under high iron concentrations and was essential for a flocculent phenotype. Furthermore, deletion of HOG1 led to

The Hog1 MAP Kinase Promotes the Recovery from Cell Cycle Arrest Induced by Hydrogen Peroxide in Candida albicans

PubMed Central

Correia, Inês; Alonso-Monge, Rebeca; Pla, Jesús

2017-01-01

Eukaryotic cell cycle progression in response to environmental conditions is controlled via specific checkpoints. Signal transduction pathways mediated by MAPKs play a crucial role in sensing stress. For example, the canonical MAPKs Mkc1 (of the cell wall integrity pathway), and Hog1 (of the HOG pathway), are activated upon oxidative stress. In this work, we have analyzed the effect of oxidative stress induced by hydrogen peroxide on cell cycle progression in Candida albicans. Hydrogen peroxide was shown to induce a transient arrest at the G1 phase of the cell cycle. Specifically, a G1 arrest was observed, although phosphorylation of Mkc1 and Hog1 MAPKs can take place at all stages of the cell cycle. Interestingly, hog1 (but not mkc1) mutants required a longer time compared to wild type cells to resume growth after hydrogen peroxide challenge. Using GFP-labeled cells and mixed cultures of wild type and hog1 cells we were able to show that hog1 mutants progress faster through the cell cycle under standard growth conditions in the absence of stress (YPD at 37°C). Consequently, hog1 mutants exhibited a smaller cell size. The altered cell cycle progression correlates with altered expression of the G1 cyclins Cln3 and Pcl2 in hog1 cells compared to the wild type strain. In addition, Hgc1 (a hypha-specific G1 cyclin) as well as Cln3 displayed a different kinetics of expression in the presence of hydrogen peroxide in hog1 mutants. Collectively, these results indicate that Hog1 regulates the expression of G1 cyclins not only in response to oxidative stress, but also under standard growth conditions. Hydrogen peroxide treated cells did not show fluctuations in the mRNA levels for SOL1, which are observed in untreated cells during cell cycle progression. In addition, treatment with hydrogen peroxide prevented degradation of Sol1, an effect which was enhanced in hog1 mutants. Therefore, in C. albicans, the MAPK Hog1 mediates cell cycle progression in response to oxidative

In a time of cholera.

PubMed

Grace, P A

2014-03-01

Dr. Nathaniel Alcock in his book A treatise on cholera described 22 cases of cholera that he treated in 1832. Blood-letting, either by leeches or venesection, was an essential part of the treatment. The belief was that reducing the blood volume would relieve stress on the heart and lungs allowing for better function. The receipts of the Townsend Street Cholera Hospital where Dr. Alcock worked show how extensive the practice was. Outside Dublin, local Boards of Health dealt with the cholera epidemic. Various public measures such as street cleaning and removal of patients to temporary hospitals were undertaken and various cures were tried. The overall mortality rate from cholera in Ireland during the epidemic was 38 %, but in some areas much higher. Even as cholera was spreading in the 1830s, a number of doctors were showing that intravenous fluids could dramatically alter the course of the disease. Unfortunately, their work was ignored and blood-letting continued to be a major component of the treatment of cholera for another 55 years.

7 CFR 1230.113 - Collection and remittance of assessments for the sale of feeder pigs and market hogs.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 10 2011-01-01 2011-01-01 false Collection and remittance of assessments for the sale of feeder pigs and market hogs. 1230.113 Section 1230.113 Agriculture Regulations of the Department... pigs and market hogs. Pursuant to the provisions of § 1230.71, purchasers of feeder pigs or market hogs...

7 CFR 1230.113 - Collection and remittance of assessments for the sale of feeder pigs and market hogs.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 10 2014-01-01 2014-01-01 false Collection and remittance of assessments for the sale of feeder pigs and market hogs. 1230.113 Section 1230.113 Agriculture Regulations of the Department... pigs and market hogs. Pursuant to the provisions of § 1230.71, purchasers of feeder pigs or market hogs...

7 CFR 1230.113 - Collection and remittance of assessments for the sale of feeder pigs and market hogs.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 10 2012-01-01 2012-01-01 false Collection and remittance of assessments for the sale of feeder pigs and market hogs. 1230.113 Section 1230.113 Agriculture Regulations of the Department... pigs and market hogs. Pursuant to the provisions of § 1230.71, purchasers of feeder pigs or market hogs...

7 CFR 1230.113 - Collection and remittance of assessments for the sale of feeder pigs and market hogs.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 10 2013-01-01 2013-01-01 false Collection and remittance of assessments for the sale of feeder pigs and market hogs. 1230.113 Section 1230.113 Agriculture Regulations of the Department... pigs and market hogs. Pursuant to the provisions of § 1230.71, purchasers of feeder pigs or market hogs...

7 CFR 1230.113 - Collection and remittance of assessments for the sale of feeder pigs and market hogs.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false Collection and remittance of assessments for the sale of feeder pigs and market hogs. 1230.113 Section 1230.113 Agriculture Regulations of the Department... pigs and market hogs. Pursuant to the provisions of § 1230.71, purchasers of feeder pigs or market hogs...

Epidemiology of Cholera in the Philippines

PubMed Central

Lopez, Anna Lena; Macasaet, Lino Y.; Ylade, Michelle; Tayag, Enrique A.; Ali, Mohammad

2015-01-01

Background Despite being a cholera-endemic country, data on cholera in the Philippines remain sparse. Knowing the areas where cholera is known to occur and the factors that lead to its occurrence will assist in planning preventive measures and disaster mitigation. Methods Using sentinel surveillance data, PubMed and ProMED searches covering information from 2008–2013 and event-based surveillance reports from 2010–2013, we assessed the epidemiology of cholera in the Philippines. Using spatial log regression, we assessed the role of water, sanitation and population density on the incidence of cholera. Results and Discussion We identified 12 articles from ProMED and none from PubMed that reported on cholera in the Philippines from 2008 to 2013. Data from ProMed and surveillance revealed 42,071 suspected and confirmed cholera cases reported from 2008 to 2013, among which only 5,006 were confirmed. 38 (47%) of 81 provinces and metropolitan regions reported at least one confirmed case of cholera and 32 (40%) reported at least one suspected case. The overall case fatality ratio in sentinel sites was 0.62%, but was 2% in outbreaks. All age groups were affected. Using both confirmed and suspected cholera cases, the average annual incidence in 2010–2013 was 9.1 per 100,000 population. Poor access to improved sanitation was consistently associated with higher cholera incidence. Paradoxically, access to improved water sources was associated with higher cholera incidence using both suspected and confirmed cholera data sources. This finding may have been due to the breakdown in the infrastructure and non-chlorination of water supplies, emphasizing the need to maintain public water systems. Conclusion Our findings confirm that cholera affects a large proportion of the provinces in the country. Identifying areas most at risk for cholera will support the development and implementation of policies to minimize the morbidity and mortality due to this disease. PMID:25569505

Outbreak of cholera in the Republic of Congo and the Democratic Republic of Congo, and cholera worldwide.

PubMed

Kelvin, Alyson Ann

2011-10-13

Cholera is an acute intestinal disease caused by infection of the Vibrio cholerae bacterium.  Often manifested as a constant diarrhoeal disease, Cholera is associated with significant mortality as well as economic loss due to the strain on health care.  Cholera often affects nations with lower economic status.  The recent outbreak of cholera in the Republic of Congo and the Democratic Republic of Congo has affected thousands of people.  Here we review the past cholera epidemiology, molecular mechanisms of the bacterium, and the political and environmental aspects that affect the treatment and eradication of this disease.

Hybrid Vibrio cholerae El Tor lacking SXT identified as the cause of a cholera outbreak in the Philippines.

PubMed

Klinzing, David C; Choi, Seon Young; Hasan, Nur A; Matias, Ronald R; Tayag, Enrique; Geronimo, Josefina; Skowronski, Evan; Rashed, Shah M; Kawashima, Kent; Rosenzweig, C Nicole; Gibbons, Henry S; Torres, Brian C; Liles, Veni; Alfon, Alicia C; Juan, Maria Luisa; Natividad, Filipinas F; Cebula, Thomas A; Colwell, Rita R

2015-04-21

Cholera continues to be a global threat, with high rates of morbidity and mortality. In 2011, a cholera outbreak occurred in Palawan, Philippines, affecting more than 500 people, and 20 individuals died. Vibrio cholerae O1 was confirmed as the etiological agent. Source attribution is critical in cholera outbreaks for proper management of the disease, as well as to control spread. In this study, three V. cholerae O1 isolates from a Philippines cholera outbreak were sequenced and their genomes analyzed to determine phylogenetic relatedness to V. cholerae O1 isolates from recent outbreaks of cholera elsewhere. The Philippines V. cholerae O1 isolates were determined to be V. cholerae O1 hybrid El Tor belonging to the seventh-pandemic clade. They clustered tightly, forming a monophyletic clade closely related to V. cholerae O1 hybrid El Tor from Asia and Africa. The isolates possess a unique multilocus variable-number tandem repeat analysis (MLVA) genotype (12-7-9-18-25 and 12-7-10-14-21) and lack SXT. In addition, they possess a novel 15-kb genomic island (GI-119) containing a predicted type I restriction-modification system. The CTXΦ-RS1 array of the Philippines isolates was similar to that of V. cholerae O1 MG116926, a hybrid El Tor strain isolated in Bangladesh in 1991. Overall, the data indicate that the Philippines V. cholerae O1 isolates are unique, differing from recent V. cholerae O1 isolates from Asia, Africa, and Haiti. Furthermore, the results of this study support the hypothesis that the Philippines isolates of V. cholerae O1 are indigenous and exist locally in the aquatic ecosystem of the Philippines. Genetic characterization and phylogenomics analysis of outbreak strains have proven to be critical for probing clonal relatedness to strains isolated in different geographical regions and over time. Recently, extensive genetic analyses of V. cholerae O1 strains isolated in different countries have been done. However, genome sequences of V. cholerae O1

Environmental bacteriophages active on biofilms and planktonic forms of toxigenic Vibrio cholerae: Potential relevance in cholera epidemiology.

PubMed

Naser, Iftekhar Bin; Hoque, M Mozammel; Abdullah, Ahmed; Bari, S M Nayeemul; Ghosh, Amar N; Faruque, Shah M

2017-01-01

Phages isolated from environmental waters in Bangladesh were tested for their host specificity towards V. cholerae O1 and O139, and the ability to disperse V. cholerae biofilms formed in the laboratory. Representative phages were further characterized by electron microscopy and whole genome sequencing. Selected phages were then introduced in various combinations to biofilms of toxigenic V. cholerae added to samples of river water, and the dispersion of biofilms as well as the growth kinetics of V. cholerae and the phages were monitored. A phage cocktail composed of three different phages isolated from surface waters in Bangladesh and designated as JSF7, JSF4, and JSF3 could significantly influence the distribution and concentration of the active planktonic form and biofilm associated form of toxigenic V. cholerae in water. While JSF7 showed a biofilm degrading activity and dispersed cells from both V. cholerae O1 and O139 derived biofilms thus increasing the concentration of planktonic V. cholerae in water, JSF4 and JSF3 showed strong bactericidal activity against V. cholerae O1 and O139 respectively. A mixture of all three phages could effectively reduce both biofilm-associated and planktonic V. cholerae in river water microcosms. Besides potential applicability in phage-mediated control of cholera, our results have relevance in appreciating possible intricate role of diverse environmental phages in the epidemiology of the disease, since both biofilms and phages influence the prevalence and infectivity of V. cholerae in a variety of ways.

Non-toxigenic environmental Vibrio cholerae O1 strain from Haiti provides evidence of pre-pandemic cholera in Hispaniola.

PubMed

Azarian, Taj; Ali, Afsar; Johnson, Judith A; Jubair, Mohammad; Cella, Eleonora; Ciccozzi, Massimo; Nolan, David J; Farmerie, William; Rashid, Mohammad H; Sinha-Ray, Shrestha; Alam, Meer T; Morris, J Glenn; Salemi, Marco

2016-10-27

Vibrio cholerae is ubiquitous in aquatic environments, with environmental toxigenic V. cholerae O1 strains serving as a source for recurrent cholera epidemics and pandemic disease. However, a number of questions remain about long-term survival and evolution of V. cholerae strains within these aquatic environmental reservoirs. Through monitoring of the Haitian aquatic environment following the 2010 cholera epidemic, we isolated two novel non-toxigenic (ctxA/B-negative) Vibrio cholerae O1. These two isolates underwent whole-genome sequencing and were investigated through comparative genomics and Bayesian coalescent analysis. These isolates cluster in the evolutionary tree with strains responsible for clinical cholera, possessing genomic components of 6 th and 7 th pandemic lineages, and diverge from "modern" cholera strains around 1548 C.E. [95% HPD: 1532-1555]. Vibrio Pathogenicity Island (VPI)-1 was present; however, SXT/R391-family ICE and VPI-2 were absent. Rugose phenotype conversion and vibriophage resistance evidenced adaption for persistence in aquatic environments. The identification of V. cholerae O1 strains in the Haitian environment, which predate the first reported cholera pandemic in 1817, broadens our understanding of the history of pandemics. It also raises the possibility that these and similar environmental strains could acquire virulence genes from the 2010 Haitian epidemic clone, including the cholera toxin producing CTXϕ.

[Evaluation of the ELISA method for cholera toxin determination in Vibrio cholerae cultures].

PubMed

González-Bonilla, C; Gutiérrez-Cogco, L; Moguel-Pech, L; Villanueva-Zamudio, A

1994-01-01

ELISA test was evaluated in 503 cultures of Vibrio cholerae O1 y 303 Non-O1. The cultures were isolated from sewage from different states of México between june 1991 and october 1992. The sensitivity was 100% and specificity was 96%. Only 12 strains of V. cholerae Non-O1 were positive for CT toxin. When these cultures were confirmed by polymerase chain reaction (PCR) for cholera toxin, the results were negative. ELISA test is a good alternative to be used for toxin production in cultures of V. cholerae, it needs confirmation only with O1 negative and Non-O1 positive reactions.

PiHOG1, a stress regulator MAP kinase from the root endophyte fungus Piriformospora indica, confers salinity stress tolerance in rice plants

PubMed Central

Jogawat, Abhimanyu; Vadassery, Jyothilakshmi; Verma, Nidhi; Oelmüller, Ralf; Dua, Meenakshi; Nevo, Eviatar; Johri, Atul Kumar

2016-01-01

In this study, yeast HOG1 homologue from the root endophyte Piriformospora indica (PiHOG1) was isolated and functionally characterized. Functional expression of PiHOG1 in S. cerevisiae ∆hog1 mutant restored osmotolerance under high osmotic stress. Knockdown (KD) transformants of PiHOG1 generated by RNA interference in P. indica showed that genes for the HOG pathway, osmoresponse and salinity tolerance were less stimulated in KD-PiHOG1 compared to the wild-type under salinity stress. Furthermore, KD lines are impaired in the colonization of rice roots under salinity stress of 200 mM NaCl, and the biomass of the host plants, their shoot and root lengths, root number, photosynthetic pigment and proline contents were reduced as compared to rice plants colonized by WT P. indica. Therefore, PiHOG1 is critical for root colonisation, salinity tolerance and the performance of the host plant under salinity stress. Moreover, downregulation of PiHOG1 resulted not only in reduced and delayed phosphorylation of the remaining PiHOG1 protein in colonized salinity-stressed rice roots, but also in the downregulation of the upstream MAP kinase genes PiPBS2 and PiSSK2 involved in salinity tolerance signalling in the fungus. Our data demonstrate that PiHOG1 is not only involved in the salinity response of P. indica, but also helping host plant to overcome salinity stress. PMID:27849025

Seasonal Cholera Caused by Vibrio cholerae Serogroups O1 and O139 in the Coastal Aquatic Environment of Bangladesh

PubMed Central

Alam, Munirul; Hasan, Nur A.; Sadique, Abdus; Bhuiyan, N. A.; Ahmed, Kabir U.; Nusrin, Suraia; Nair, G. Balakrish; Siddique, A. K.; Sack, R. Bradley; Sack, David A.; Huq, Anwar; Colwell, Rita R.

2006-01-01

Since Vibrio cholerae O139 first appeared in 1992, both O1 El Tor and O139 have been recognized as the epidemic serogroups, although their geographic distribution, endemicity, and reservoir are not fully understood. To address this lack of information, a study of the epidemiology and ecology of V. cholerae O1 and O139 was carried out in two coastal areas, Bakerganj and Mathbaria, Bangladesh, where cholera occurs seasonally. The results of a biweekly clinical study (January 2004 to May 2005), employing culture methods, and of an ecological study (monthly in Bakerganj and biweekly in Mathbaria from March 2004 to May 2005), employing direct and enrichment culture, colony blot hybridization, and direct fluorescent-antibody methods, showed that cholera is endemic in both Bakerganj and Mathbaria and that V. cholerae O1, O139, and non-O1/non-O139 are autochthonous to the aquatic environment. Although V. cholerae O1 and O139 were isolated from both areas, most noteworthy was the isolation of V. cholerae O139 in March, July, and September 2004 in Mathbaria, where seasonal cholera was clinically linked only to V. cholerae O1. In Mathbaria, V. cholerae O139 emerged as the sole cause of a significant outbreak of cholera in March 2005. V. cholerae O1 reemerged clinically in April 2005 and established dominance over V. cholerae O139, continuing to cause cholera in Mathbaria. In conclusion, the epidemic potential and coastal aquatic reservoir for V. cholerae O139 have been demonstrated. Based on the results of this study, the coastal ecosystem of the Bay of Bengal is concluded to be a significant reservoir for the epidemic serogroups of V. cholerae. PMID:16751520

Environmental signatures associated with cholera epidemics

PubMed Central

Constantin de Magny, Guillaume; Murtugudde, Raghu; Sapiano, Mathew R. P.; Nizam, Azhar; Brown, Christopher W.; Busalacchi, Antonio J.; Yunus, Mohammad; Nair, G. Balakrish; Gil, Ana I.; Lanata, Claudio F.; Calkins, John; Manna, Byomkesh; Rajendran, Krishnan; Bhattacharya, Mihir Kumar; Huq, Anwar; Sack, R. Bradley; Colwell, Rita R.

2008-01-01

The causative agent of cholera, Vibrio cholerae, has been shown to be autochthonous to riverine, estuarine, and coastal waters along with its host, the copepod, a significant member of the zooplankton community. Temperature, salinity, rainfall and plankton have proven to be important factors in the ecology of V. cholerae, influencing the transmission of the disease in those regions of the world where the human population relies on untreated water as a source of drinking water. In this study, the pattern of cholera outbreaks during 1998–2006 in Kolkata, India, and Matlab, Bangladesh, and the earth observation data were analyzed with the objective of developing a prediction model for cholera. Satellite sensors were used to measure chlorophyll a concentration (CHL) and sea surface temperature (SST). In addition, rainfall data were obtained from both satellite and in situ gauge measurements. From the analyses, a statistically significant relationship between the time series for cholera in Kolkata, India, and CHL and rainfall anomalies was determined. A statistically significant one month lag was observed between CHL anomaly and number of cholera cases in Matlab, Bangladesh. From the results of the study, it is concluded that ocean and climate patterns are useful predictors of cholera epidemics, with the dynamics of endemic cholera being related to climate and/or changes in the aquatic ecosystem. When the ecology of V. cholerae is considered in predictive models, a robust early warning system for cholera in endemic regions of the world can be developed for public health planning and decision making. PMID:19001267

Multi-site cholera surveillance within the African Cholera Surveillance Network shows endemicity in Mozambique, 2011-2015.

PubMed

Semá Baltazar, Cynthia; Langa, José Paulo; Dengo Baloi, Liliana; Wood, Richard; Ouedraogo, Issaka; Njanpop-Lafourcade, Berthe-Marie; Inguane, Dorteia; Elias Chitio, Jucunu; Mhlanga, Themba; Gujral, Lorna; D Gessner, Bradford; Munier, Aline; A Mengel, Martin

2017-10-01

Mozambique suffers recurrent annual cholera outbreaks especially during the rainy season between October to March. The African Cholera Surveillance Network (Africhol) was implemented in Mozambique in 2011 to generate accurate detailed surveillance data to support appropriate interventions for cholera control and prevention in the country. Africhol was implemented in enhanced surveillance zones located in the provinces of Sofala (Beira), Zambézia (District Mocuba), and Cabo Delgado (Pemba City). Data were also analyzed from the three outbreak areas that experienced the greatest number of cases during the time period under observation (in the districts of Cuamba, Montepuez, and Nampula). Rectal swabs were collected from suspected cases for identification of Vibrio cholerae, as well as clinical, behavioral, and socio-demographic variables. We analyzed factors associated with confirmed, hospitalized, and fatal cholera using multivariate logistic regression models. A total of 1,863 suspected cases and 23 deaths (case fatality ratio (CFR), 1.2%) were reported from October 2011 to December 2015. Among these suspected cases, 52.2% were tested of which 23.5% were positive for Vibrio cholerae O1 Ogawa. Risk factors independently associated with the occurrence of confirmed cholera were living in Nampula city district, the year 2014, human immunodeficiency virus infection, and the primary water source for drinking. Cholera was endemic in Mozambique during the study period with a high CFR and identifiable risk factors. The study reinforces the importance of continued cholera surveillance, including a strong laboratory component. The results enhanced our understanding of the need to target priority areas and at-risk populations for interventions including oral cholera vaccine (OCV) use, and assess the impact of prevention and control strategies. Our data were instrumental in informing integrated prevention and control efforts during major cholera outbreaks in recent years.

Hybrid Vibrio cholerae El Tor Lacking SXT Identified as the Cause of a Cholera Outbreak in the Philippines

PubMed Central

Klinzing, David C.; Choi, Seon Young; Hasan, Nur A.; Matias, Ronald R.; Tayag, Enrique; Geronimo, Josefina; Skowronski, Evan; Rashed, Shah M.; Kawashima, Kent; Rosenzweig, C. Nicole; Gibbons, Henry S.; Torres, Brian C.; Liles, Veni; Alfon, Alicia C.; Juan, Maria Luisa; Natividad, Filipinas F.; Cebula, Thomas A.

2015-01-01

ABSTRACT Cholera continues to be a global threat, with high rates of morbidity and mortality. In 2011, a cholera outbreak occurred in Palawan, Philippines, affecting more than 500 people, and 20 individuals died. Vibrio cholerae O1 was confirmed as the etiological agent. Source attribution is critical in cholera outbreaks for proper management of the disease, as well as to control spread. In this study, three V. cholerae O1 isolates from a Philippines cholera outbreak were sequenced and their genomes analyzed to determine phylogenetic relatedness to V. cholerae O1 isolates from recent outbreaks of cholera elsewhere. The Philippines V. cholerae O1 isolates were determined to be V. cholerae O1 hybrid El Tor belonging to the seventh-pandemic clade. They clustered tightly, forming a monophyletic clade closely related to V. cholerae O1 hybrid El Tor from Asia and Africa. The isolates possess a unique multilocus variable-number tandem repeat analysis (MLVA) genotype (12-7-9-18-25 and 12-7-10-14-21) and lack SXT. In addition, they possess a novel 15-kb genomic island (GI-119) containing a predicted type I restriction-modification system. The CTXΦ-RS1 array of the Philippines isolates was similar to that of V. cholerae O1 MG116926, a hybrid El Tor strain isolated in Bangladesh in 1991. Overall, the data indicate that the Philippines V. cholerae O1 isolates are unique, differing from recent V. cholerae O1 isolates from Asia, Africa, and Haiti. Furthermore, the results of this study support the hypothesis that the Philippines isolates of V. cholerae O1 are indigenous and exist locally in the aquatic ecosystem of the Philippines. PMID:25900650

Environmental Monitoring of Endemic Cholera

NASA Astrophysics Data System (ADS)

ElNemr, W.; Jutla, A. S.; Constantin de Magny, G.; Hasan, N. A.; Islam, M.; Sack, R.; Huq, A.; Hashem, F.; Colwell, R.

2012-12-01

Cholera remains a major public health threat. Since Vibrio cholerae, the causative agent of the disease, is autochthonous to riverine, estuarine, and coastal waters, it is unlikely the bacteria can be eradicated from its natural habitat. Prediction of disease, in conjunction with preventive vaccination can reduce the prevalence rate of a disease. Understanding the influence of environmental parameters on growth and proliferation of bacteria is an essential first step in developing prediction methods for outbreaks. Large scale geophysical variables, such as SST and coastal chlorophyll, are often associated with conditions favoring growth of V. cholerae. However, local environmental factors, meaning biological activity in ponds from where the bulk of populations in endemic regions derive water for daily usage, are either neglected or oversimplified. Using data collected from several sites in two geographically distinct locations in South Asia, we have identified critical local environmental factors associated with cholera outbreak. Of 18 environmental variables monitored for water sources in Mathbaria (a coastal site near the Bay of Bengal) and Bakergonj (an inland site) of Bangladesh, water depth and chlorophyll were found to be important factors associated with initiation of cholera outbreaks. Cholera in coastal regions appears to be related to intrusion. However, monsoonal flooding creates conditions for cholera epidemics in inland regions. This may be one of the first attempts to relate in-situ environmental observations with cholera. We anticipate that it will be useful for further development of prediction models in the resource constrained regions.

Antibiotics resistance in El Tor Vibrio cholerae 01 isolated during cholera outbreaks in Mozambique from 2012 to 2015

PubMed Central

2017-01-01

Rationale Mozambique has recorded cyclically epidemic outbreaks of cholera. Antibiotic therapy is recommended in specific situations for management and control of cholera outbreaks. However, an increase in resistance rates to antibiotics by Vibrio cholerae has been reported in several epidemic outbreaks worldwide. On the other hand, there are few recent records of continuous surveillance of antibiotics susceptibility pattern of V. cholerae in Mozambique. Goals The purpose of this study was to evaluate antibiotics resistance pattern of Vibrio cholerae O1 Ogawa isolated during Cholera outbreaks in Mozambique to commonly used antibiotics. Methodology We analyzed data from samples received in the context of surveillance and response to Cholera outbreaks in the National Reference Laboratory of Microbiology from the National Institute of Health of Mozambique, 159 samples suspected of cholera from cholera treatment centers of, Metangula (09), Memba (01), Tete City (08), Moatize (01), Morrumbala (01) districts, City of Quelimane (01), Lichinga (06) and Nampula (86) districts, from 2012 to 2015. Laboratory culture and standard biochemical tests were employed to isolate and identify Vibrio cholerae; serotypes were determined by antisera agglutination reaction in blade. Biotype and presence of important virulence factors analysis was done by PCR. Antibiotics susceptibility pattern was detected by disk diffusion method Kirby Bauer. Antibiotic susceptibility and results were interpreted by following as per recommendations of CLSI (Clinical and Laboratory Standards Institute) 2014. All samples were collected and tested in the context of Africhol Project, approved by the National Bioethics Committee for Health. Results Among isolates from of Vibrio cholerae O1 El Tor Ogawa resistance to Sulphamethoxazole-trimethropim was 100% (53/53) to Trimethoprim-, being 100% (54/54) for Ampicillin, 99% (72/74) for Nalidixic Acid, 97% (64/66) to Chloramphenicol, 95% (42/44) for Nitrofurantoin

Antibiotics resistance in El Tor Vibrio cholerae 01 isolated during cholera outbreaks in Mozambique from 2012 to 2015.

PubMed

Dengo-Baloi, Liliana Candida; Semá-Baltazar, Cynthia Amino; Manhique, Lena Vania; Chitio, Jucunu Elias; Inguane, Dorteia Luísa; Langa, José Paulo

2017-01-01

Mozambique has recorded cyclically epidemic outbreaks of cholera. Antibiotic therapy is recommended in specific situations for management and control of cholera outbreaks. However, an increase in resistance rates to antibiotics by Vibrio cholerae has been reported in several epidemic outbreaks worldwide. On the other hand, there are few recent records of continuous surveillance of antibiotics susceptibility pattern of V. cholerae in Mozambique. The purpose of this study was to evaluate antibiotics resistance pattern of Vibrio cholerae O1 Ogawa isolated during Cholera outbreaks in Mozambique to commonly used antibiotics. We analyzed data from samples received in the context of surveillance and response to Cholera outbreaks in the National Reference Laboratory of Microbiology from the National Institute of Health of Mozambique, 159 samples suspected of cholera from cholera treatment centers of, Metangula (09), Memba (01), Tete City (08), Moatize (01), Morrumbala (01) districts, City of Quelimane (01), Lichinga (06) and Nampula (86) districts, from 2012 to 2015. Laboratory culture and standard biochemical tests were employed to isolate and identify Vibrio cholerae; serotypes were determined by antisera agglutination reaction in blade. Biotype and presence of important virulence factors analysis was done by PCR. Antibiotics susceptibility pattern was detected by disk diffusion method Kirby Bauer. Antibiotic susceptibility and results were interpreted by following as per recommendations of CLSI (Clinical and Laboratory Standards Institute) 2014. All samples were collected and tested in the context of Africhol Project, approved by the National Bioethics Committee for Health. Among isolates from of Vibrio cholerae O1 El Tor Ogawa resistance to Sulphamethoxazole-trimethropim was 100% (53/53) to Trimethoprim-, being 100% (54/54) for Ampicillin, 99% (72/74) for Nalidixic Acid, 97% (64/66) to Chloramphenicol, 95% (42/44) for Nitrofurantoin and (19/20) Cotrimoxazole, 83% (80

Elevation and cholera: an epidemiological spatial analysis of the cholera epidemic in Harare, Zimbabwe, 2008-2009

PubMed Central

2012-01-01

Background In highly populated African urban areas where access to clean water is a challenge, water source contamination is one of the most cited risk factors in a cholera epidemic. During the rainy season, where there is either no sewage disposal or working sewer system, runoff of rains follows the slopes and gets into the lower parts of towns where shallow wells could easily become contaminated by excretes. In cholera endemic areas, spatial information about topographical elevation could help to guide preventive interventions. This study aims to analyze the association between topographic elevation and the distribution of cholera cases in Harare during the cholera epidemic in 2008 and 2009. Methods We developed an ecological study using secondary data. First, we described attack rates by suburb and then calculated rate ratios using whole Harare as reference. We illustrated the average elevation and cholera cases by suburbs using geographical information. Finally, we estimated a generalized linear mixed model (under the assumption of a Poisson distribution) with an Empirical Bayesian approach to model the relation between the risk of cholera and the elevation in meters in Harare. We used a random intercept to allow for spatial correlation of neighboring suburbs. Results This study identifies a spatial pattern of the distribution of cholera cases in the Harare epidemic, characterized by a lower cholera risk in the highest elevation suburbs of Harare. The generalized linear mixed model showed that for each 100 meters of increase in the topographical elevation, the cholera risk was 30% lower with a rate ratio of 0.70 (95% confidence interval=0.66-0.76). Sensitivity analysis confirmed the risk reduction with an overall estimate of the rate ratio between 20% and 40%. Conclusion This study highlights the importance of considering topographical elevation as a geographical and environmental risk factor in order to plan cholera preventive activities linked with water and

Cholera in the Americas.

PubMed

1991-01-01

The cholera epidemic 1st hit South America in January 1991 in the coastal town of Chancay, Peru. In 2 weeks, it spread over 2000 km of the Pacific coast. By the end of the 1st month, it had already reached the mountains and tropical forests. By August 1991, cholera cases were reported in order of appearances in Ecuador, Colombia, Chile, Brazil, the US, Mexico, Guatemala, Bolivia, and El Salvador. Health authorities still do not know how it was introduced into South America. The case fatality rate has remained at a low of 1%, probably due to the prompt actions of health authorities in informing the public of the epidemic and what preventive cautions should be taken. This epidemic is part of the 7th pandemic which originated in Celebes, Indonesia in 1961. Cholera can spread relatively unchecked in Latin America because sewage in urban areas is not treated even though they do have sewage collection systems. The untreated wastewater enters rivers and the ocean. Consumption of raw seafood is not unusual and has been responsible for cholera infection in some cases. In fact, many countries placed import restrictions on marine products from Peru following the outbreak at a loss of $US10-$US40 million. Municipal sewage treatment facilities, especially stabilization ponds, would prevent the spread of cholera and other pathogens. In rural areas, pit latrines located away from wells can effectively dispose of human wastes. Most water supplies in Latin America are not disinfected. Disinfection drinking water with adequate levels of chlorine would effectively destroy V. cholera. If this is not possible, boiling the water for 2-3 minutes would destroy the pathogen. Any cases of cholera must be reported to PAHO. PAHO has responded to the outbreak by forming a Cholera Task Force and arranged transport of oral rehydration salts, intravenous fluids, antibiotics, and other essential medical supplies.

Phylogenetic Diversity of Vibrio cholerae Associated with Endemic Cholera in Mexico from 1991 to 2008

PubMed Central

Choi, Seon Young; Rashed, Shah M.; Hasan, Nur A.; Alam, Munirul; Islam, Tarequl; Sadique, Abdus; Johura, Fatema-Tuz; Eppinger, Mark; Huq, Anwar; Cravioto, Alejandro

2016-01-01

ABSTRACT An outbreak of cholera occurred in 1991 in Mexico, where it had not been reported for more than a century and is now endemic. Vibrio cholerae O1 prototype El Tor and classical strains coexist with altered El Tor strains (1991 to 1997). Nontoxigenic (CTX−) V. cholerae El Tor dominated toxigenic (CTX+) strains (2001 to 2003), but V. cholerae CTX+ variant El Tor was isolated during 2004 to 2008, outcompeting CTX− V. cholerae. Genomes of six Mexican V. cholerae O1 strains isolated during 1991 to 2008 were sequenced and compared with both contemporary and archived strains of V. cholerae. Three were CTX+ El Tor, two were CTX− El Tor, and the remaining strain was a CTX+ classical isolate. Whole-genome sequence analysis showed the six isolates belonged to five distinct phylogenetic clades. One CTX− isolate is ancestral to the 6th and 7th pandemic CTX+ V. cholerae isolates. The other CTX− isolate joined with CTX− non-O1/O139 isolates from Haiti and seroconverted O1 isolates from Brazil and Amazonia. One CTX+ isolate was phylogenetically placed with the sixth pandemic classical clade and the V. cholerae O395 classical reference strain. Two CTX+ El Tor isolates possessing intact Vibrio seventh pandemic island II (VSP-II) are related to hybrid El Tor isolates from Mozambique and Bangladesh. The third CTX+ El Tor isolate contained West African-South American (WASA) recombination in VSP-II and showed relatedness to isolates from Peru and Brazil. Except for one isolate, all Mexican isolates lack SXT/R391 integrative conjugative elements (ICEs) and sensitivity to selected antibiotics, with one isolate resistant to streptomycin. No isolates were related to contemporary isolates from Asia, Africa, or Haiti, indicating phylogenetic diversity. PMID:26980836

Multi-site cholera surveillance within the African Cholera Surveillance Network shows endemicity in Mozambique, 2011–2015

PubMed Central

Langa, José Paulo; Dengo Baloi, Liliana; Wood, Richard; Ouedraogo, Issaka; Njanpop-Lafourcade, Berthe-Marie; Inguane, Dorteia; Elias Chitio, Jucunu; Mhlanga, Themba; Gujral, Lorna; D. Gessner, Bradford; Munier, Aline; A. Mengel, Martin

2017-01-01

Background Mozambique suffers recurrent annual cholera outbreaks especially during the rainy season between October to March. The African Cholera Surveillance Network (Africhol) was implemented in Mozambique in 2011 to generate accurate detailed surveillance data to support appropriate interventions for cholera control and prevention in the country. Methodology/Principal findings Africhol was implemented in enhanced surveillance zones located in the provinces of Sofala (Beira), Zambézia (District Mocuba), and Cabo Delgado (Pemba City). Data were also analyzed from the three outbreak areas that experienced the greatest number of cases during the time period under observation (in the districts of Cuamba, Montepuez, and Nampula). Rectal swabs were collected from suspected cases for identification of Vibrio cholerae, as well as clinical, behavioral, and socio-demographic variables. We analyzed factors associated with confirmed, hospitalized, and fatal cholera using multivariate logistic regression models. A total of 1,863 suspected cases and 23 deaths (case fatality ratio (CFR), 1.2%) were reported from October 2011 to December 2015. Among these suspected cases, 52.2% were tested of which 23.5% were positive for Vibrio cholerae O1 Ogawa. Risk factors independently associated with the occurrence of confirmed cholera were living in Nampula city district, the year 2014, human immunodeficiency virus infection, and the primary water source for drinking. Conclusions/Significance Cholera was endemic in Mozambique during the study period with a high CFR and identifiable risk factors. The study reinforces the importance of continued cholera surveillance, including a strong laboratory component. The results enhanced our understanding of the need to target priority areas and at-risk populations for interventions including oral cholera vaccine (OCV) use, and assess the impact of prevention and control strategies. Our data were instrumental in informing integrated prevention and

[Improvement of laboratory diagnostics of cholera due to genetically altered (hybrid) variants of cholera Vibrio biovar El Tor].

PubMed

Savel'eva, I V; Khatsukov, K X; Savel'eva, E I; Moskvitina, S I; Kovalev, D A; Savel'ev, V N; Kulichenko, A N; Antonenko, A D; Babenyshev, B V

2015-01-01

Improvement of laboratory diagnostics of cholera taking into the account appearance of hybrid variants of cholera vibrio El Tor biovar in the 1990s. Phenotypic and molecular-genetic properties of typical toxigenic (151 strains) and hybrid (102 strains) variants of El Tor biovar cholera vibrios, isolated in the Caucuses in 1970-1990 and 1993-1998, respectively, were studied. Toxigenicity gene DNA fragments, inherent to El Tor biovars or classic, were detected by using a reagent kit "Genes of Vibrio cholerae variant ctxB-rstR-rstC, REF" developed by us. Reagent kit "Genes of V. cholerae variant ctxB-rstR-rstC, REF" is proposed to be used for laboratory diagnostics of cholera during study of material from humans or environmental objects and for identification of V. cholerae 01 on genome level in PCR-analysis as a necessary addition to the classic scheme of bacteriological analysis. Laboratory diagnostics of cholera due to genetically altered (hybrid) variants of cholera vibrio El Tor biovar is based on a complex study of material from humans and environmental objects by routine bacteriologic and PCR-analysis methods with the aim of detection of gene DNA fragments in the studied material, that determine biovar (classic or El Tor), identification of V. cholerae O1 strains with differentiation of El Tor vibrios into typical and altered, as well as determination of enterotoxin, produced by the specific cholera vibrio strain (by the presence ctxB(El) or ctxB(Cl) gene DNA fragment, coding biosynthesis of CT-2 or CT-1, respectively).

Mitogen-activated protein kinase Hog1 is activated in response to curcumin exposure in the budding yeast Saccharomyces cerevisiae.

PubMed

Azad, Gajendra Kumar; Singh, Vikash; Thakare, Mayur Jankiram; Baranwal, Shivani; Tomar, Raghuvir Singh

2014-12-19

Curcumin (CUR), an active polyphenol derived from the spice turmeric, has been traditionally used for centuries in ancient Indian medicine to treat a number of diseases. The physiological effects of CUR have been shown to be diverse; however, the target molecules and pathways that CUR affects have yet to be fully described. Here, we demonstrate for the first time that the budding yeast mitogen-activated protein kinase (MAPK) Hog1 is essential for the response to CUR. Moreover, CUR-induced Hog1 phosphorylation was rescued by supplementation of iron to the growth medium. Hog1 was rapidly phosphorylated upon CUR treatment, but unlike the response to hyperosmotic shock (0.8 M NaCl), it remains activated for an extended period of time. A detailed analysis of HOG pathway mutants revealed that Pbs2p, Ptc2p, and Ssk2p are required for optimal CUR-induced Hog1 phosphorylation. We also observed a Hog1 dependent transcriptional response to CUR treatment that involved the up-regulation of glycerol-3-phosphate dehydrogenase 1 (GPD1), a factor that is essential for the hyperosmotic stress response. Our present finding revealed the role of Hog1 MAPK in regulation of CUR-induced transcriptional response. We anticipate that our finding will enhance the understanding on the molecular mode of action of CUR on S. cerevisiae.

22. William E. Barrett, Photographer, August 1975. CHIPPER OR 'HOG' ...

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

22. William E. Barrett, Photographer, August 1975. CHIPPER OR 'HOG' FOR REDUCING SCRAPS TO WOOD CHIPS. HOUSING PARTIALLY REMOVED. - Meadow River Lumber Company, Highway 60, Rainelle, Greenbrier County, WV

Genomic and Phenotypic Characterization of Vibrio cholerae Non-O1 Isolates from a US Gulf Coast Cholera Outbreak

PubMed Central

Grim, Christopher J.; Onifade, Tiffiani J.; Cinar, Hediye N.; Tall, Ben D.; Taviani, Elisa; Hasan, Nur A.; Abdullah, AbdulShakur H.; Carter, Laurenda; Sahu, Surasri N.; Kothary, Mahendra H.; Chen, Arlene; Baker, Ron; Hutchinson, Richard; Blackmore, Carina; Cebula, Thomas A.; Huq, Anwar; Colwell, Rita R.

2014-01-01

Between November 2010, and May 2011, eleven cases of cholera, unrelated to a concurrent outbreak on the island of Hispaniola, were recorded, and the causative agent, Vibrio cholerae serogroup O75, was traced to oysters harvested from Apalachicola Bay, Florida. From the 11 diagnosed cases, eight isolates of V. cholerae were isolated and their genomes were sequenced. Genomic analysis demonstrated the presence of a suite of mobile elements previously shown to be involved in the disease process of cholera (ctxAB, VPI-1 and -2, and a VSP-II like variant) and a phylogenomic analysis showed the isolates to be sister taxa to toxigenic V. cholerae V51 serogroup O141, a clinical strain isolated 23 years earlier. Toxigenic V. cholerae O75 has been repeatedly isolated from clinical cases in the southeastern United States and toxigenic V. cholerae O141 isolates have been isolated globally from clinical cases over several decades. Comparative genomics, phenotypic analyses, and a Caenorhabditis elegans model of infection for the isolates were conducted. This analysis coupled with isolation data of V. cholerae O75 and O141 suggests these strains may represent an underappreciated clade of cholera-causing strains responsible for significant disease burden globally. PMID:24699521

Genomic and phenotypic characterization of Vibrio cholerae non-O1 isolates from a US Gulf Coast cholera outbreak.

PubMed

Haley, Bradd J; Choi, Seon Young; Grim, Christopher J; Onifade, Tiffiani J; Cinar, Hediye N; Tall, Ben D; Taviani, Elisa; Hasan, Nur A; Abdullah, Abdulshakur H; Carter, Laurenda; Sahu, Surasri N; Kothary, Mahendra H; Chen, Arlene; Baker, Ron; Hutchinson, Richard; Blackmore, Carina; Cebula, Thomas A; Huq, Anwar; Colwell, Rita R

2014-01-01

Between November 2010, and May 2011, eleven cases of cholera, unrelated to a concurrent outbreak on the island of Hispaniola, were recorded, and the causative agent, Vibrio cholerae serogroup O75, was traced to oysters harvested from Apalachicola Bay, Florida. From the 11 diagnosed cases, eight isolates of V. cholerae were isolated and their genomes were sequenced. Genomic analysis demonstrated the presence of a suite of mobile elements previously shown to be involved in the disease process of cholera (ctxAB, VPI-1 and -2, and a VSP-II like variant) and a phylogenomic analysis showed the isolates to be sister taxa to toxigenic V. cholerae V51 serogroup O141, a clinical strain isolated 23 years earlier. Toxigenic V. cholerae O75 has been repeatedly isolated from clinical cases in the southeastern United States and toxigenic V. cholerae O141 isolates have been isolated globally from clinical cases over several decades. Comparative genomics, phenotypic analyses, and a Caenorhabditis elegans model of infection for the isolates were conducted. This analysis coupled with isolation data of V. cholerae O75 and O141 suggests these strains may represent an underappreciated clade of cholera-causing strains responsible for significant disease burden globally.

Cholera Prevention and Control

MedlinePlus

... name=”commit” type=”submit” value=”Submit” /> Prevention & Control Recommend on Facebook Tweet Share Compartir Prevention of ... of cholera and other diarrheal disease prevention. Prevention & Control Topics Ending Cholera: The Global Roadmap to 2030 ...

Cholera studies*†

PubMed Central

Pollitzer, R.

1955-01-01

The morphological characteristics, biochemical properties, and cultural characteristics of V. cholerae are described in great detail in this study. The author also discusses the resistance of the organism to temperature, humidity, sunlight, and various chemicals, as well as the viability of V. cholerae outside the body (in faeces, contaminated material, food, beverages, water, etc.). PMID:14379012

Boron contents and isotopic compositions of hog manure, selected fertilizers, and water in Minnesota

USGS Publications Warehouse

Komor, S.C.

1997-01-01

Boron-isotope (δ11B) values may be useful as surrogate tracers of contaminants and indicators of water mixing in agricultural settings. This paper characterizes the B contents and isotopic compositions of hog manure and selected fertilizers, and presents δ11B data for ground and surface water from two agricultural areas. Boron concentrations in dry hog manure averaged 61 mg/kg and in commercial fertilizers ranged from below detection limits in some brands of ammonium nitrate and urea to 382 mg/kg in magnesium sulfate. Values of δ11B of untreated hog manure ranged from 7.2 to 11.2o/oo and of N fertilizers were −2.0 to 0.7o/oo. In 22 groundwater samples from a sand-plain aquifer in east-central Minnesota, B concentrations averaged 0.04 mg/L and δ11B values ranged from 2.3 to 41.5o/oo. Groundwater beneath a hog feedlot and a cultivated field where hog manure was applied had B-isotope compositions consistent with the water containing hog-manure leachate. In a 775-km2 watershed with silty-loam soils in southcentral Minnesota: 18 samples of subsurface drainage from corn (Zea mays L.) and soybean (Glycine max L. Merr.) fields had average B concentrations of 0.06 mg/L and δ11B values of 5.3 to 15.1o/oo; 27 stream samples had average B concentrations of 0.05 mg/L and δ11B values of 1.0 to 19.0o/oo; and eight groundwater samples had average B concentrations of 0.09 mg/L and δ11B values of −0.3 to 23.0o/oo. Values of δ11B and B concentrations, when plotted against one another, define a curved mixing trend that suggests subsurface drainage and stream water contain mixtures of B from shallow and deep groundwater.

Biology of Vibrio cholera. Editorial overview.

PubMed

Cava, Felipe

2017-09-01

In this monographic issue, we have the pleasure to present contributions from six of the leading laboratories at the forefront of Vibrio cholerae genetics, ecology and evolution, together with a brief tribute by Diego Romero to Doctor Jaime Ferrán y Clua, a pioneering Spanish bacteriologist who developed the first vaccine against this pathogen. V. cholerae is a free-living aquatic bacterium that interacts with and infects a variety of organisms. In humans it causes cholera, the deadly diarrhoea that was responsible for millions of deaths during seven pandemics since 1817, and still thousands every year. The Boucher lab presents a study of the ecology, evolution and dispersal of pandemic V. cholerae biotypes in relation to environmental reservoirs. They show how both species-specific and lineage-specific genetic determinants play a role in the ability of V. cholerae strains to cause pandemics, having evolved gradually over centuries. One of the key aspects that makes a particularly successful pathogen is its genomic plasticity. The V. cholerae genome contains a superintegron (SI) that is involved in development and dissemination of antibiotic resistance genes among diverse bacterial species, permitting population expansion in challenging conditions. Escudero and Mazel review the SI as a true hotspot of V. cholerae's genomic diversity and low-cost memory of adaptive functions in its complex lifestyle and ecology. Another remarkable aspect of V. cholerae 's genetics is the presence of two chromosomes. Segregation and division in multi-chromosomal becteria is relatively complex, and V. cholerae remains the paradigm. Espinosa and colleagues review the cell cycle of V. cholerae , comparing and contrasting with that of E. coli . In addition to genome plasticity, V. cholerae uses a variety of attack/defence strategies to compete and thrive in different niches, through interaction with bacteriophages, bacteria and eukaryotes. The role of phages in the life cycle of V

Antibacterial activity of Psidium guajava leaf and bark against multidrug-resistant Vibrio cholerae: implication for cholera control.

PubMed

Rahim, Niaz; Gomes, Donald James; Watanabe, Haruo; Rahman, Sabita Rizwana; Chomvarin, Chariya; Endtz, Hubert Ph; Alam, Munirul

2010-07-01

In clinical cholera, a 3-day course of antibiotic complements extensive rehydration therapy by reducing stool volume, shortening the illness, and averting death. However, antibiotic therapy, which has lifesaving implications for cholera, is often hindered due to multidrug resistance in Vibrio cholerae, the cause of cholera. Crude aqueous mixture and water soluble methanol extract from leaf and bark of Psidium guajava, a tropical fruit guava of the family Myrtaceae, showed strong antibacterial activity against multidrug-resistant V. cholerae O1. The in vitro minimum inhibitory concentration of the crude aqueous mixture and water soluble methanol extract, which was bactericidal against 10(7) CFU/mL of V. cholerae was determined to be 1,250 microg/mL and 850 microg/mL, respectively. The antibacterial activity of P. guajava was stable at 100 degrees C for 15-20 min, suggesting nonprotein nature of the active component. The growth of V. cholerae in rice oral rehydration saline (ORS) was completely inhibited when 10 mg/mL (wt/vol) of crude aqueous mixture was premixed with the ORS in a ratio of 1:7 (vol. extract/vol. ORS). P. guajava, which is widely distributed in Bangladesh, thus offers great potential for use in indigenous, herbal medicine for controlling epidemics of cholera.

Vibrio cholerae Colonization of Soft-Shelled Turtles

PubMed Central

Wang, Jiazheng; Yan, Meiying; Gao, He; Lu, Xin

2017-01-01

ABSTRACT Vibrio cholerae is an important human pathogen and environmental microflora species that can both propagate in the human intestine and proliferate in zooplankton and aquatic organisms. Cholera is transmitted through food and water. In recent years, outbreaks caused by V. cholerae-contaminated soft-shelled turtles, contaminated mainly with toxigenic serogroup O139, have been frequently reported, posing a new foodborne disease public health problem. In this study, the colonization by toxigenic V. cholerae on the body surfaces and intestines of soft-shelled turtles was explored. Preferred colonization sites on the turtle body surfaces, mainly the carapace and calipash of the dorsal side, were observed for the O139 and O1 strains. Intestinal colonization was also found. The colonization factors of V. cholerae played different roles in the colonization of the soft-shelled turtle's body surface and intestine. Mannose-sensitive hemagglutinin (MSHA) of V. cholerae was necessary for body surface colonization, but no roles were found for toxin-coregulated pili (TCP) or N-acetylglucosamine-binding protein A (GBPA). Both TCP and GBPA play important roles for colonization in the intestine, whereas the deletion of MSHA revealed only a minor colonization-promoting role for this factor. Our study demonstrated that V. cholerae can colonize the surfaces and the intestines of soft-shelled turtles and indicated that the soft-shelled turtles played a role in the transmission of cholera. In addition, this study showed that the soft-shelled turtle has potential value as an animal model in studies of the colonization and environmental adaption mechanisms of V. cholerae in aquatic organisms. IMPORTANCE Cholera is transmitted through water and food. Soft-shelled turtles contaminated with Vibrio cholerae (commonly the serogroup O139 strains) have caused many foodborne infections and outbreaks in recent years, and they have become a foodborne disease problem. Except for

Vibrio cholerae Colonization of Soft-Shelled Turtles.

PubMed

Wang, Jiazheng; Yan, Meiying; Gao, He; Lu, Xin; Kan, Biao

2017-07-15

Vibrio cholerae is an important human pathogen and environmental microflora species that can both propagate in the human intestine and proliferate in zooplankton and aquatic organisms. Cholera is transmitted through food and water. In recent years, outbreaks caused by V. cholerae -contaminated soft-shelled turtles, contaminated mainly with toxigenic serogroup O139, have been frequently reported, posing a new foodborne disease public health problem. In this study, the colonization by toxigenic V. cholerae on the body surfaces and intestines of soft-shelled turtles was explored. Preferred colonization sites on the turtle body surfaces, mainly the carapace and calipash of the dorsal side, were observed for the O139 and O1 strains. Intestinal colonization was also found. The colonization factors of V. cholerae played different roles in the colonization of the soft-shelled turtle's body surface and intestine. Mannose-sensitive hemagglutinin (MSHA) of V. cholerae was necessary for body surface colonization, but no roles were found for toxin-coregulated pili (TCP) or N -acetylglucosamine-binding protein A (GBPA). Both TCP and GBPA play important roles for colonization in the intestine, whereas the deletion of MSHA revealed only a minor colonization-promoting role for this factor. Our study demonstrated that V. cholerae can colonize the surfaces and the intestines of soft-shelled turtles and indicated that the soft-shelled turtles played a role in the transmission of cholera. In addition, this study showed that the soft-shelled turtle has potential value as an animal model in studies of the colonization and environmental adaption mechanisms of V. cholerae in aquatic organisms. IMPORTANCE Cholera is transmitted through water and food. Soft-shelled turtles contaminated with Vibrio cholerae (commonly the serogroup O139 strains) have caused many foodborne infections and outbreaks in recent years, and they have become a foodborne disease problem. Except for epidemiological

Dynamics in genome evolution of Vibrio cholerae.

PubMed

Banerjee, Rachana; Das, Bhabatosh; Balakrish Nair, G; Basak, Surajit

2014-04-01

Vibrio cholerae, the etiological agent of the acute secretary diarrheal disease cholera, is still a major public health concern in developing countries. In former centuries cholera was a permanent threat even to the highly developed populations of Europe, North America, and the northern part of Asia. Extensive studies on the cholera bug over more than a century have made significant advances in our understanding of the disease and ways of treating patients. V. cholerae has more than 200 serogroups, but only few serogroups have caused disease on a worldwide scale. Until the present, the evolutionary relationship of these pandemic causing serogroups was not clear. In the last decades, we have witnessed a shift involving genetically and phenotypically varied pandemic clones of V. cholerae in Asia and Africa. The exponential knowledge on the genome of several representatives V. cholerae strains has been used to identify and analyze the key determinants for rapid evolution of cholera pathogen. Recent comparative genomic studies have identified the presence of various integrative mobile genetic elements (IMGEs) in V. cholerae genome, which can be used as a marker of differentiation of all seventh pandemic clones with very similar core genome. This review attempts to bring together some of the important researches in recent times that have contributed towards understanding the genetics, epidemiology and evolution of toxigenic V. cholerae strains. Copyright © 2014 Elsevier B.V. All rights reserved.

Cholera outbreaks (2012) in three districts of Nepal reveal clonal transmission of multi-drug resistant Vibrio cholerae O1

PubMed Central

2014-01-01

Background Although endemic cholera causes significant morbidity and mortality each year in Nepal, lack of information about the causal bacterium often hinders cholera intervention and prevention. In 2012, diarrheal outbreaks affected three districts of Nepal with confirmed cases of mortality. This study was designed to understand the drug response patterns, source, and transmission of Vibrio cholerae associated with 2012 cholera outbreaks in Nepal. Methods V. cholerae (n = 28) isolated from 2012 diarrhea outbreaks {n = 22; Kathmandu (n = 12), Doti (n = 9), Bajhang (n = 1)}, and surface water (n = 6; Kathmandu) were tested for antimicrobial response. Virulence properties and DNA fingerprinting of the strains were determined by multi-locus genetic screening employing polymerase chain reaction, DNA sequencing, and pulsed-field gel electrophoresis (PFGE). Results All V. cholerae strains isolated from patients and surface water were confirmed to be toxigenic, belonging to serogroup O1, Ogawa serotype, biotype El Tor, and possessed classical biotype cholera toxin (CTX). Double-mismatch amplification mutation assay (DMAMA)-PCR revealed the V. cholerae strains to possess the B-7 allele of ctx subunit B. DNA sequencing of tcpA revealed a point mutation at amino acid position 64 (N → S) while the ctxAB promoter revealed four copies of the tandem heptamer repeat sequence 5'-TTTTGAT-3'. V. cholerae possessed all the ORFs of the Vibrio seventh pandemic island (VSP)-I but lacked the ORFs 498–511 of VSP-II. All strains were multidrug resistant with resistance to trimethoprim-sulfamethoxazole (SXT), nalidixic acid (NA), and streptomycin (S); all carried the SXT genetic element. DNA sequencing and deduced amino acid sequence of gyrA and parC of the NAR strains (n = 4) revealed point mutations at amino acid positions 83 (S → I), and 85 (S → L), respectively. Similar PFGE (NotI) pattern revealed the Nepalese V. cholerae to be clonal

Relationship between Distinct African Cholera Epidemics Revealed via MLVA Haplotyping of 337 Vibrio cholerae Isolates.

PubMed

Moore, Sandra; Miwanda, Berthe; Sadji, Adodo Yao; Thefenne, Hélène; Jeddi, Fakhri; Rebaudet, Stanislas; de Boeck, Hilde; Bidjada, Bawimodom; Depina, Jean-Jacques; Bompangue, Didier; Abedi, Aaron Aruna; Koivogui, Lamine; Keita, Sakoba; Garnotel, Eric; Plisnier, Pierre-Denis; Ruimy, Raymond; Thomson, Nicholas; Muyembe, Jean-Jacques; Piarroux, Renaud

2015-01-01

Since cholera appeared in Africa during the 1970s, cases have been reported on the continent every year. In Sub-Saharan Africa, cholera outbreaks primarily cluster at certain hotspots including the African Great Lakes Region and West Africa. In this study, we applied MLVA (Multi-Locus Variable Number Tandem Repeat Analysis) typing of 337 Vibrio cholerae isolates from recent cholera epidemics in the Democratic Republic of the Congo (DRC), Zambia, Guinea and Togo. We aimed to assess the relationship between outbreaks. Applying this method, we identified 89 unique MLVA haplotypes across our isolate collection. MLVA typing revealed the short-term divergence and microevolution of these Vibrio cholerae populations to provide insight into the dynamics of cholera outbreaks in each country. Our analyses also revealed strong geographical clustering. Isolates from the African Great Lakes Region (DRC and Zambia) formed a closely related group, while West African isolates (Togo and Guinea) constituted a separate cluster. At a country-level scale our analyses revealed several distinct MLVA groups, most notably DRC 2011/2012, DRC 2009, Zambia 2012 and Guinea 2012. We also found that certain MLVA types collected in the DRC persisted in the country for several years, occasionally giving rise to expansive epidemics. Finally, we found that the six environmental isolates in our panel were unrelated to the epidemic isolates. To effectively combat the disease, it is critical to understand the mechanisms of cholera emergence and diffusion in a region-specific manner. Overall, these findings demonstrate the relationship between distinct epidemics in West Africa and the African Great Lakes Region. This study also highlights the importance of monitoring and analyzing Vibrio cholerae isolates.

Molecular Characterization of the Circulating Strains of Vibrio cholerae during 2010 Cholera Outbreak in Nigeria

PubMed Central

Oyedeji, Kolawole S.; Niemogha, Mary-Theresa; Nwaokorie, Francisca O.; Bamidele, Tajudeen A.; Ochoga, Michael; Akinsinde, Kehinde A.; Brai, Bartholomew I.; Oladele, David; Omonigbehin, Emmanuel A.; Bamidele, Moses; Fesobi, Toun W.; Musa, Adesola Z.; Adeneye, Adeniyi K.; Ujah, Innocent A.

2013-01-01

This study aimed at characterizing the phenotypic and toxigenic status of circulating strains of cholera during outbreaks in Nigeria, employing molecular typing techniques. Two hundred and one samples of rectal swabs, stool, vomitus, water (from the well, borehole, sachet, stream, and tap) and disinfectants (sodium hypochlorite) were collected from three states in the country. The samples were inoculated on thiosulphate-citrate bile salt-sucrose (TCBS), Cary-Blair transport medium and smeared on glass slides for direct examination. The Vibrio cholerae isolates were serotyped, biotyped, and characterized using PCR of the cytotoxin gene A (ctxA), wbeO1, and wbfO139 gene primer. Of the 201 samples screened, 96 were positive for V. cholerae O1 (48%), with 69 (72%) positive for ctxA gene. The results from this study showed that the circulating strains of cholera in Nigeria were of Ogawa serotype, also observed in other outbreaks in Nigeria (1991, 1992, and 1996). However, the strains were of the Classical biotype and were mainly (72%) ctxA gene-positive. This current investigation has confirmed the production of cholera toxin by the circulating strains, and this could be harnessed for possible cholera vaccine production in Nigeria. PMID:23930335

Genetic characteristics of drug-resistant Vibrio cholerae O1 causing endemic cholera in Dhaka, 2006–2011

PubMed Central

Rashed, Shah M.; Mannan, Shahnewaj B.; Johura, Fatema-tuz; Islam, M. Tarequl; Sadique, Abdus; Watanabe, Haruo; Sack, R. Bradley; Huq, Anwar; Colwell, Rita R.; Cravioto, Alejandro

2012-01-01

Vibrio cholerae O1 biotype El Tor (ET), causing the seventh cholera pandemic, was recently replaced in Bangladesh by an altered ET possessing ctxB of the Classical (CL) biotype, which caused the first six cholera pandemics. In the present study, V. cholerae O1 strains associated with endemic cholera in Dhaka between 2006 and 2011 were analysed for major phenotypic and genetic characteristics. Of 54 representative V. cholerae isolates tested, all were phenotypically ET and showed uniform resistance to trimethoprim/sulfamethoxazole (SXT) and furazolidone (FR). Resistance to tetracycline (TE) and erythromycin (E) showed temporal fluctuation, varying from year to year, while all isolates were susceptible to gentamicin (CN) and ciprofloxacin (CIP). Year-wise data revealed erythromycin resistance to be 33.3 % in 2006 and 11 % in 2011, while tetracycline resistance accounted for 33, 78, 0, 100 and 27 % in 2006, 2007, 2008, 2009 and 2010, respectively; interestingly, all isolates tested were sensitive to TE in 2011, as observed in 2008. All V. cholerae isolates tested possessed genetic elements such as SXT, ctxAB, tcpAET, rstRET and rtxC; none had IntlI (Integron I). Double mismatch amplification mutation assay (DMAMA)-PCR followed by DNA sequencing and analysis of the ctxB gene revealed a point mutation at position 58 (C→A), which has resulted in an amino acid substitution from histidine (H) to asparagine (N) at position 20 (genotype 7) since 2008. Although the multi-resistant strains having tetracycline resistance showed minor genetic divergence, V. cholerae strains were clonal, as determined by a PFGE (NotI)-based dendrogram. This study shows 2008–2010 to be the time of transition from ctxB genotype 1 to genotype 7 in V. cholerae ET causing endemic cholera in Dhaka, Bangladesh. PMID:22977073

Cholera studies*

PubMed Central

Swaroop, S.; Pollitzer, R.

1955-01-01

In this study, figures relating to cholera deaths occurring in individual countries, from 1900 to 1952, are recorded as well as the incidence of the disease from 1923 up to the present time. The mode of spread of cholera from its endemic home in India to outside countries is described in relation to favourable seasons, main routes followed by the infection, and the role played by large religious gatherings. The incidence of the disease in the various seaports infected within recent years is discussed. PMID:14364186

Evaluation of the SD Bioline Cholera Rapid Diagnostic Test During the 2016 Cholera Outbreak in Lusaka, Zambia.

PubMed

Mwaba, John; Ferreras, Eva; Chizema-Kawesa, Elizabeth; Mwimbe, Daniel; Tafirenyika, Francis; Rauzier, Jean; Blake, Alexandre; Rakesh, Ankur; Poncin, Marc; Stoitsova, Savina; Kwenda, Geoffrey; Azman, Andrew S; Chewe, Orbrie; Serafini, Micaela; Lukwesa-Musyani, Chileshe; Cohuet, Sandra; Quilici, Marie-Laure; Luquero, Francisco J; Page, Anne-Laure

2018-05-31

To assess the performance of the SD Bioline Cholera Ag O1/O139 rapid diagnostic test (RDT) compared to a reference standard combining culture and PCR for the diagnosis of cholera cases during an outbreak. RDT and bacterial culture were performed on site using fresh stools collected from cholera suspected cases, and from stools enriched in alkaline peptone water. Dried stool samples on filter paper were tested for V. cholerae by PCR in Lusaka (as part of a laboratory technology transfer project) and at a reference laboratory in Paris, France. A sample was considered positive for cholera by the reference standard if any of the culture or PCR tests was positive for V. cholerae O1 or O139. Among the 170 samples tested with SD Bioline and compared to the reference standard, the RDT showed a sensitivity of 90.9% (95% CI: 81.3-96.6) and specificity of 95.0% (95% CI: 89.1-98.4). After enrichment, the sensitivity was 95.5% (95% CI: 87.3-99.1) and specificity 100% (5% CI: 96.5-100). The observed sensitivity and specificity were within recommendations set by the Global Task Force for Cholera Control on the use of cholera RDT (sensitivity=90% : specificity=85%). Although the sample size was small, our findings suggest that the SD Bioline RDT could be used in the field to rapidly alert public health officials to the likely presence of cholera cases when an outbreak is suspected. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Epidemic cholera spreads like wildfire

NASA Astrophysics Data System (ADS)

Roy, Manojit; Zinck, Richard D.; Bouma, Menno J.; Pascual, Mercedes

2014-01-01

Cholera is on the rise globally, especially epidemic cholera which is characterized by intermittent and unpredictable outbreaks that punctuate periods of regional disease fade-out. These epidemic dynamics remain however poorly understood. Here we examine records for epidemic cholera over both contemporary and historical timelines, from Africa (1990-2006) and former British India (1882-1939). We find that the frequency distribution of outbreak size is fat-tailed, scaling approximately as a power-law. This pattern which shows strong parallels with wildfires is incompatible with existing cholera models developed for endemic regions, as it implies a fundamental role for stochastic transmission and local depletion of susceptible hosts. Application of a recently developed forest-fire model indicates that epidemic cholera dynamics are located above a critical phase transition and propagate in similar ways to aggressive wildfires. These findings have implications for the effectiveness of control measures and the mechanisms that ultimately limit the size of outbreaks.

Environmental Factors Influencing Epidemic Cholera

PubMed Central

Jutla, Antarpreet; Whitcombe, Elizabeth; Hasan, Nur; Haley, Bradd; Akanda, Ali; Huq, Anwar; Alam, Munir; Sack, R. Bradley; Colwell, Rita

2013-01-01

Cholera outbreak following the earthquake of 2010 in Haiti has reaffirmed that the disease is a major public health threat. Vibrio cholerae is autochthonous to aquatic environment, hence, it cannot be eradicated but hydroclimatology-based prediction and prevention is an achievable goal. Using data from the 1800s, we describe uniqueness in seasonality and mechanism of occurrence of cholera in the epidemic regions of Asia and Latin America. Epidemic regions are located near regional rivers and are characterized by sporadic outbreaks, which are likely to be initiated during episodes of prevailing warm air temperature with low river flows, creating favorable environmental conditions for growth of cholera bacteria. Heavy rainfall, through inundation or breakdown of sanitary infrastructure, accelerates interaction between contaminated water and human activities, resulting in an epidemic. This causal mechanism is markedly different from endemic cholera where tidal intrusion of seawater carrying bacteria from estuary to inland regions, results in outbreaks. PMID:23897993

Epidemic cholera spreads like wildfire

PubMed Central

Roy, Manojit; Zinck, Richard D.; Bouma, Menno J.; Pascual, Mercedes

2014-01-01

Cholera is on the rise globally, especially epidemic cholera which is characterized by intermittent and unpredictable outbreaks that punctuate periods of regional disease fade-out. These epidemic dynamics remain however poorly understood. Here we examine records for epidemic cholera over both contemporary and historical timelines, from Africa (1990–2006) and former British India (1882–1939). We find that the frequency distribution of outbreak size is fat-tailed, scaling approximately as a power-law. This pattern which shows strong parallels with wildfires is incompatible with existing cholera models developed for endemic regions, as it implies a fundamental role for stochastic transmission and local depletion of susceptible hosts. Application of a recently developed forest-fire model indicates that epidemic cholera dynamics are located above a critical phase transition and propagate in similar ways to aggressive wildfires. These findings have implications for the effectiveness of control measures and the mechanisms that ultimately limit the size of outbreaks. PMID:24424273

Epidemic cholera spreads like wildfire.

PubMed

Roy, Manojit; Zinck, Richard D; Bouma, Menno J; Pascual, Mercedes

2014-01-15

Cholera is on the rise globally, especially epidemic cholera which is characterized by intermittent and unpredictable outbreaks that punctuate periods of regional disease fade-out. These epidemic dynamics remain however poorly understood. Here we examine records for epidemic cholera over both contemporary and historical timelines, from Africa (1990-2006) and former British India (1882-1939). We find that the frequency distribution of outbreak size is fat-tailed, scaling approximately as a power-law. This pattern which shows strong parallels with wildfires is incompatible with existing cholera models developed for endemic regions, as it implies a fundamental role for stochastic transmission and local depletion of susceptible hosts. Application of a recently developed forest-fire model indicates that epidemic cholera dynamics are located above a critical phase transition and propagate in similar ways to aggressive wildfires. These findings have implications for the effectiveness of control measures and the mechanisms that ultimately limit the size of outbreaks.

Sustained Local Diversity of Vibrio cholerae O1 Biotypes in a Previously Cholera-Free Country

PubMed Central

2016-01-01

ABSTRACT Although the current cholera pandemic can trace its origin to a specific time and place, many variants of Vibrio cholerae have caused this disease over the last 50 years. The relative clinical importance and geographical distribution of these variants have changed with time, but most remain in circulation. Some countries, such as Mexico and Haiti, had escaped the current pandemic, until large epidemics struck them in 1991 and 2010, respectively. Cholera has been endemic in these countries ever since. A recent retrospective study in mBio presents the results of more than 3 decades of V. cholerae monitoring from environmental and clinical sources in Mexico (S. Y. Choi et al., mBio 7:e02160-15, 2016, http://dx.doi.org/10.1128/mBio.02160-15). It reveals that multiple V. cholerae variants, including classical strains from the previous pandemic, as well as completely novel biotypes, have been circulating in Mexico. This discovery has important implications for the epidemiology and evolution of V. cholerae. PMID:27143391

Sustained Local Diversity of Vibrio cholerae O1 Biotypes in a Previously Cholera-Free Country.

PubMed

Boucher, Yan

2016-05-03

Although the current cholera pandemic can trace its origin to a specific time and place, many variants of Vibrio cholerae have caused this disease over the last 50 years. The relative clinical importance and geographical distribution of these variants have changed with time, but most remain in circulation. Some countries, such as Mexico and Haiti, had escaped the current pandemic, until large epidemics struck them in 1991 and 2010, respectively. Cholera has been endemic in these countries ever since. A recent retrospective study in mBio presents the results of more than 3 decades of V. cholerae monitoring from environmental and clinical sources in Mexico (S. Y. Choi et al., mBio 7:e02160-15, 2016, http://dx.doi.org/10.1128/mBio.02160-15). It reveals that multiple V. cholerae variants, including classical strains from the previous pandemic, as well as completely novel biotypes, have been circulating in Mexico. This discovery has important implications for the epidemiology and evolution of V. cholerae. Copyright © 2016 Boucher.

How Will Climate Change Impact Cholera Outbreaks?

NASA Astrophysics Data System (ADS)

Nasr Azadani, F.; Jutla, A.; Rahimikolu, J.; Akanda, A. S.; Huq, A.; Colwell, R. R.

2014-12-01

Environmental parameters associated with cholera are well documented. However, cholera continues to be a global public health threat. Uncertainty in defining environmental processes affecting growth and multiplication of the cholera bacteria can be affected significantly by changing climate at different temporal and spatial scales, either through amplification of the hydroclimatic cycle or by enhanced variability of large scale geophysical processes. Endemic cholera in the Bengal Delta region of South Asia has a unique pattern of two seasonal peaks and there are associated with asymmetric and episodic variability in river discharge. The first cholera outbreak in spring is related with intrusion of bacteria laden coastal seawater during low river discharge. Cholera occurring during the fall season is hypothesized to be associated with high river discharge related to a cross-contamination of water resources and, therefore, a second wave of disease, a phenomenon characteristic primarily in the inland regions. Because of difficulties in establishing linkage between coarse resolutions of the Global Climate Model (GCM) output and localized disease outbreaks, the impact of climate change on diarrheal disease has not been explored. Here using the downscaling method of Support Vector Machines from HADCM3 and ECHAM models, we show how cholera outbreak patterns are changing in the Bengal Delta. Our preliminary results indicate statistically significant changes in both seasonality and magnitude in the occurrence of cholera over the next century. Endemic cholera is likely to transform into epidemic forms and new geographical areas will be at risk for cholera outbreaks.

Vaxchora: A Single-Dose Oral Cholera Vaccine.

PubMed

Cabrera, Adriana; Lepage, Jayne E; Sullivan, Karyn M; Seed, Sheila M

2017-07-01

To review trials evaluating the efficacy and safety of Vaxchora, a reformulated, single-dose, oral, lyophilized Vibrio cholerae CVD 103-HgR vaccine for the prevention of travel-related cholera caused by V cholerae serogroup O1. A literature search was conducted using MEDLINE (1946 to January week 3, 2017) and EMBASE (1996 to 2017 week 3). Keywords included oral cholera vaccine, single-dose, Vaxchora, and CVD 103-HgR. Limits included human, clinical trials published in English since 2010. ClinicalTrials.gov was used as a source for unpublished data. Additional data sources were obtained through bibliographic review of selected articles. Studies that addressed the safety and efficacy of Vaxchora, the reformulated, single-dose oral CVD 103-HgR cholera vaccine, were selected for analysis. Approval of Vaxchora, was based on efficacy of the vaccine in human trials demonstrating 90.3% protection among those challenged with V cholerae 10 days after vaccination and in immunogenicity studies with 90% systemic vibriocidal antibody conversion at 6 months after a single-dose of vaccine. Tolerability was acceptable, with the most common adverse effects reported to be fatigue, headache, and abdominal pain. Vaxchora is the only FDA-approved, single-dose oral vaccine for the prevention of cholera caused by V cholerae serogroup O1 in adult travelers from the United States going to cholera-affected areas. Safety and efficacy has not been established in children, immunocompromised persons, and pregnant or breastfeeding women or those living in cholera-endemic areas.

[Complications and treatment of cholera during pregnancy].

PubMed

Figueroa Damian, R; Villagrana Zesati, R; Kasis Ariceaga, D

1994-07-01

Since 1961 cholera has spread in many countries reaching a pandemic form. Since 1991 Mexico has been involved in this pandemia. Near 20% of all cases of cholera in our country happen in fertile women, so the possibility of the association between cholera and pregnancy is high. We present the case of a pregnant woman, who during her third trimester presented a episode of cholera, developing premature labor. Furthermore is revised the medical literature about the general principles of the management of cholera, and the association between pregnancy and the intestinal infection.

The Vaccine Candidate Vibrio cholerae 638 Is Protective against Cholera in Healthy Volunteers

PubMed Central

García, Luis; Jidy, Manuel Díaz; García, Hilda; Rodríguez, Boris L.; Fernández, Roberto; Año, Gemma; Cedré, Bárbara; Valmaseda, Tania; Suzarte, Edith; Ramírez, Margarita; Pino, Yadira; Campos, Javier; Menéndez, Jorge; Valera, Rodrigo; González, Daniel; González, Irma; Pérez, Oliver; Serrano, Teresita; Lastre, Miriam; Miralles, Fernando; del Campo, Judith; Maestre, Jorge Luis; Pérez, José Luis; Talavera, Arturo; Pérez, Antonio; Marrero, Karen; Ledón, Talena; Fando, Rafael

2005-01-01

Vibrio cholerae 638 is a living candidate cholera vaccine strain attenuated by deletion of the CTXΦ prophage from C7258 (O1, El Tor Ogawa) and by insertion of the Clostridium thermocellum endoglucanase A gene into the hemagglutinin/protease coding sequence. This vaccine candidate was previously found to be well tolerated and immunogenic in volunteers. This article reports a randomized, double-blind, placebo-controlled trial conducted to test short-term protection conferred by 638 against subsequent V. cholerae infection and disease in volunteers in Cuba. A total of 45 subjects were enrolled and assigned to receive vaccine or placebo. The vaccine contained 109 CFU of freshly harvested 638 buffered with 1.3% NaHCO3, while the placebo was buffer alone. After vaccine but not after placebo intake, 96% of volunteers had at least a fourfold increase in vibriocidal antibody titers, and 50% showed a doubling of at least the lipopolysaccharide-specific immunoglobulin A titers in serum. At 1 month after vaccination, five volunteers from the vaccine group and five from the placebo group underwent an exploratory challenge study with 109 CFU of ΔCTXΦ attenuated mutant strain V. cholerae 81. Only two volunteers from the vaccine group shed strain 81 in their feces, but none of them experienced diarrhea; in the placebo group, all volunteers excreted the challenge strain, and three had reactogenic diarrhea. An additional 12 vaccinees and 9 placebo recipients underwent challenge with 7 × 105 CFU of virulent strain V. cholerae 3008 freshly harvested from a brain heart infusion agar plate and buffered with 1.3% NaHCO3. Three volunteers (25%) from the vaccine group and all from the placebo group shed the challenge agent in their feces. None of the 12 vaccinees but 7 volunteers from the placebo group had diarrhea, and 2 of the latter exhibited severe cholera (>5,000 g of diarrheal stool). These results indicate that at 1 month after ingestion of a single oral dose (109 CFU) of strain

The vaccine candidate Vibrio cholerae 638 is protective against cholera in healthy volunteers.

PubMed

García, Luis; Jidy, Manuel Díaz; García, Hilda; Rodríguez, Boris L; Fernández, Roberto; Año, Gemma; Cedré, Bárbara; Valmaseda, Tania; Suzarte, Edith; Ramírez, Margarita; Pino, Yadira; Campos, Javier; Menéndez, Jorge; Valera, Rodrigo; González, Daniel; González, Irma; Pérez, Oliver; Serrano, Teresita; Lastre, Miriam; Miralles, Fernando; Del Campo, Judith; Maestre, Jorge Luis; Pérez, José Luis; Talavera, Arturo; Pérez, Antonio; Marrero, Karen; Ledón, Talena; Fando, Rafael

2005-05-01

Vibrio cholerae 638 is a living candidate cholera vaccine strain attenuated by deletion of the CTXPhi prophage from C7258 (O1, El Tor Ogawa) and by insertion of the Clostridium thermocellum endoglucanase A gene into the hemagglutinin/protease coding sequence. This vaccine candidate was previously found to be well tolerated and immunogenic in volunteers. This article reports a randomized, double-blind, placebo-controlled trial conducted to test short-term protection conferred by 638 against subsequent V. cholerae infection and disease in volunteers in Cuba. A total of 45 subjects were enrolled and assigned to receive vaccine or placebo. The vaccine contained 10(9) CFU of freshly harvested 638 buffered with 1.3% NaHCO(3), while the placebo was buffer alone. After vaccine but not after placebo intake, 96% of volunteers had at least a fourfold increase in vibriocidal antibody titers, and 50% showed a doubling of at least the lipopolysaccharide-specific immunoglobulin A titers in serum. At 1 month after vaccination, five volunteers from the vaccine group and five from the placebo group underwent an exploratory challenge study with 10(9) CFU of DeltaCTXPhi attenuated mutant strain V. cholerae 81. Only two volunteers from the vaccine group shed strain 81 in their feces, but none of them experienced diarrhea; in the placebo group, all volunteers excreted the challenge strain, and three had reactogenic diarrhea. An additional 12 vaccinees and 9 placebo recipients underwent challenge with 7 x 10(5) CFU of virulent strain V. cholerae 3008 freshly harvested from a brain heart infusion agar plate and buffered with 1.3% NaHCO(3). Three volunteers (25%) from the vaccine group and all from the placebo group shed the challenge agent in their feces. None of the 12 vaccinees but 7 volunteers from the placebo group had diarrhea, and 2 of the latter exhibited severe cholera (>5,000 g of diarrheal stool). These results indicate that at 1 month after ingestion of a single oral dose (10

Vibrio cholerae Serogroup O139: Isolation from Cholera Patients and Asymptomatic Household Family Members in Bangladesh between 2013 and 2014.

PubMed

Chowdhury, Fahima; Mather, Alison E; Begum, Yasmin Ara; Asaduzzaman, Muhammad; Baby, Nabilah; Sharmin, Salma; Biswas, Rajib; Uddin, Muhammad Ikhtear; LaRocque, Regina C; Harris, Jason B; Calderwood, Stephen B; Ryan, Edward T; Clemens, John D; Thomson, Nicholas R; Qadri, Firdausi

2015-11-01

Cholera is endemic in Bangladesh, with outbreaks reported annually. Currently, the majority of epidemic cholera reported globally is El Tor biotype Vibrio cholerae isolates of the serogroup O1. However, in Bangladesh, outbreaks attributed to V. cholerae serogroup O139 isolates, which fall within the same phylogenetic lineage as the O1 serogroup isolates, were seen between 1992 and 1993 and in 2002 to 2005. Since then, V. cholerae serogroup O139 has only been sporadically isolated in Bangladesh and is now rarely isolated elsewhere. Here, we present case histories of four cholera patients infected with V. cholerae serogroup O139 in 2013 and 2014 in Bangladesh. We comprehensively typed these isolates using conventional approaches, as well as by whole genome sequencing. Phenotypic typing and PCR confirmed all four isolates belonging to the O139 serogroup. Whole genome sequencing revealed that three of the isolates were phylogenetically closely related to previously sequenced El Tor biotype, pandemic 7, toxigenic V. cholerae O139 isolates originating from Bangladesh and elsewhere. The fourth isolate was a non-toxigenic V. cholerae that, by conventional approaches, typed as O139 serogroup but was genetically divergent from previously sequenced pandemic 7 V. cholerae lineages belonging to the O139 or O1 serogroups. These results suggest that previously observed lineages of V. cholerae O139 persist in Bangladesh and can cause clinical disease and that a novel disease-causing non-toxigenic O139 isolate also occurs.

[Vibrio cholerae sepsis in the neonate].

PubMed

Santamaría Muñoz, R; Ramírez Aguilera, P; Pansza, R; Acevedo, E; Hernández Estrada, E

2002-10-01

Vibrio cholerae sepsis is infrequent, especially in neonates although sporadic cases have been reported in older patients. We report the case of a neonate who was admitted to the intensive care unit for hypovolemic shock secondary to diarrhea caused by V. cholerae that developed into bacteremia. The predisposing factors were low socioeconomic status, home delivery, delayed presentation at the health center, and active maternal gastrointestinal infection with V. cholerae. The organism identified in blood and feces culture was identified as V. cholerae 0 -1, biotype Thor, serotype Ogawa, which correlated with the clinical presentation.

The incubation period of cholera: a systematic review.

PubMed

Azman, Andrew S; Rudolph, Kara E; Cummings, Derek A T; Lessler, Justin

2013-05-01

Recent large cholera outbreaks highlight the need for improved understanding of the pathogenesis and epidemiology of cholera. The incubation period of cholera has important implications for clinical and public health decision-making, yet statements of the incubation period of cholera are often imprecise. Here we characterize the distribution of cholera's incubation period. We conducted a systematic review of the literature for statements of the incubation period of cholera and data that might aid in its estimation. We extracted individual-level data, parametrically estimated the distribution of toxigenic cholera's incubation period, and evaluated evidence for differences between strains. The incubation period did not differ by a clinically significant margin between strains (except O1 El Tor Ogawa). We estimate the median incubation period of toxigenic cholera to be 1.4 days (95% CI, 1.3-1.6). Five percent of cholera cases will develop symptoms by 0.5 days (95% CI 0.4-0.5), and 95% by 4.4 days (95% CI 3.9-5.0) after infection. We recommend that cholera investigations use a recall period of at least five days to capture relevant exposures; significantly longer than recent risk factor studies from the Haitian epidemic. This characterization of cholera's incubation period can help improve clinical and public health practice and advance epidemiologic research. Copyright © 2012 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

[Alteration of cholera toxin biosynthesis in Vibrio cholerae 01 as a result of temperate phage 139 integration into bacterial chromosome].

PubMed

Eroshenko, G A; Smirnova, N I

2002-01-01

Infection of V. cholerae 01 (classical and eltor biovars) cells with the temperate cholera phage 139 derived from V. cholerae serogroup 0139 followed by integration of the phage genome into the bacterial chromosome significantly increased the production of cholera toxin, the main virulence factor. The level of toxin biosynthesis in the lysogenic V. cholerae classical strain increased 3-fold and that in V. eltor thirty times in comparison with the parental strains. Increased production of cholera toxin was not associated with an increase in the number of copies of genes involved in its biosynthesis but seemed to be due to changes in toxinogenesis regulation.

Dissecting the role of histidine kinase and HOG1 mitogen-activated protein kinase signalling in stress tolerance and pathogenicity of Parastagonospora nodorum on wheat

PubMed Central

John, Evan; Lopez-Ruiz, Francisco; Rybak, Kasia; Mousley, Carl J.; Oliver, Richard P.

2016-01-01

The HOG1 mitogen-activated protein kinase (MAPK) pathway is activated through two-component histidine kinase (HK) signalling. This pathway was first characterized in the budding yeast Saccharomyces cerevisiae as a regulator of osmotolerance. The fungus Parastagonospora nodorum is the causal agent of septoria nodorum blotch of wheat. This pathogen uses host-specific effectors in tandem with general pathogenicity mechanisms to carry out its infection process. Genes showing strong sequence homology to S. cerevisiae HOG1 signalling pathway genes have been identified in the genome of P. nodorum. In this study, we examined the role of the pathway in the virulence of P. nodorum on wheat by disrupting putative pathway component genes: HOG1 (SNOG_13296) MAPK and NIK1 (SNOG_11631) hybrid HK. Mutants deleted in NIK1 and HOG1 were insensitive to dicarboximide and phenylpyrrole fungicides, but not a fungicide that targets ergosterol biosynthesis. Furthermore, both Δnik1 and Δhog1 mutants showed increased sensitivity to hyperosmotic stress. However, HOG1, but not NIK1, is required for tolerance to elevated temperatures. HOG1 deletion conferred increased tolerance to 6-methoxy-2-benzoxazolinone, a cereal phytoalexin. This suggests that the HOG1 signalling pathway is not exclusively associated with NIK1. Both Δnik1 and Δhog1 mutants retained the ability to infect and cause necrotic lesions on wheat. However, we observed that the Δhog1 mutation resulted in reduced production of pycnidia, asexual fruiting bodies that facilitate spore dispersal during late infection. Our study demonstrated the overlapping and distinct roles of a HOG1 MAPK and two-component HK signalling in P. nodorum growth and pathogenicity. PMID:26978567

Reconstruction of the High-Osmolarity Glycerol (HOG) Signaling Pathway from the Halophilic Fungus Wallemia ichthyophaga in Saccharomyces cerevisiae.

PubMed

Konte, Tilen; Terpitz, Ulrich; Plemenitaš, Ana

2016-01-01

The basidiomycetous fungus Wallemia ichthyophaga grows between 1.7 and 5.1 M NaCl and is the most halophilic eukaryote described to date. Like other fungi, W. ichthyophaga detects changes in environmental salinity mainly by the evolutionarily conserved high-osmolarity glycerol (HOG) signaling pathway. In Saccharomyces cerevisiae, the HOG pathway has been extensively studied in connection to osmotic regulation, with a valuable knock-out strain collection established. In the present study, we reconstructed the architecture of the HOG pathway of W. ichthyophaga in suitable S. cerevisiae knock-out strains, through heterologous expression of the W. ichthyophaga HOG pathway proteins. Compared to S. cerevisiae, where the Pbs2 (ScPbs2) kinase of the HOG pathway is activated via the SHO1 and SLN1 branches, the interactions between the W. ichthyophaga Pbs2 (WiPbs2) kinase and the W. ichthyophaga SHO1 branch orthologs are not conserved: as well as evidence of poor interactions between the WiSho1 Src-homology 3 (SH3) domain and the WiPbs2 proline-rich motif, the absence of a considerable part of the osmosensing apparatus in the genome of W. ichthyophaga suggests that the SHO1 branch components are not involved in HOG signaling in this halophilic fungus. In contrast, the conserved activation of WiPbs2 by the S. cerevisiae ScSsk2/ScSsk22 kinase and the sensitivity of W. ichthyophaga cells to fludioxonil, emphasize the significance of two-component (SLN1-like) signaling via Group III histidine kinase. Combined with protein modeling data, our study reveals conserved and non-conserved protein interactions in the HOG signaling pathway of W. ichthyophaga and therefore significantly improves the knowledge of hyperosmotic signal processing in this halophilic fungus.

Tracking Cholera in Coastal Regions using Satellite Observations

PubMed Central

Jutla, Antarpreet S; Akanda, Ali S; Islam, Shafiqul

2010-01-01

Cholera remains a significant health threat across the globe. The pattern and magnitude of the seven global pandemics suggest that cholera outbreaks primarily originate in coastal regions and then spread inland through secondary means. Cholera bacteria show strong association with plankton abundance in coastal ecosystems. This review study investigates relationship(s) between cholera incidence and coastal processes and explores utility of using remote sensing data to track coastal plankton blooms, using chlorophyll as a surrogate variable for plankton abundance, and subsequent cholera outbreaks. Most studies over the last several decades have primarily focused on the microbiological and epidemiological understanding of cholera outbreaks. Accurate identification and mechanistic understanding of large scale climatic, geophysical and oceanic processes governing cholera-chlorophyll relationship is important for developing cholera prediction models. Development of a holistic understanding of these processes requires long and reliable chlorophyll dataset(s), which are beginning to be available through satellites. We have presented a schematic pathway and a modeling framework that relate cholera with various hydroclimatic and oceanic variables for understanding disease dynamics using latest advances in remote sensing. Satellite data, with its unprecedented spatial and temporal coverage, have potentials to monitor coastal processes and track cholera outbreaks in endemic regions. PMID:21072249

Detection of cholera (ctx) and zonula occludens (zot) toxin genes in Vibrio cholerae O1, O139 and non-O1 strains.

PubMed

Rivera, I G; Chowdhury, M A; Sanchez, P S; Sato, M I; Huq, A; Colwell, R R; Martins, M T

1995-09-01

Vibrio cholerae O1 and V. cholerae non-O1 strains isolated from environmental samples collected in São Paulo, Brazil, during cholera epidemics and pre-epidemic periods were examined for the presence of toxin genes. V. cholerae O1 strains isolated from clinical samples in Peru and Mexico, and V. cholerae O139 strains from India were also examined for the presence of ctx (cholera toxin gene) and zot (zonula occludens toxin gene) by polymerase chain reaction (PCR). A modified DNA-extraction method applied in this study yielded satisfactory recovery of genomic DNA from vibrios. Results showed that strains of V. cholerae O1 isolated during the preepidemic period were ctx (-)/zot (-) whereas strains isolated during the epidemic were ctx (+)/zot (+). All V. cholerae non-O1 strains tested in the study were ctx (-)/zot (-), whereas all V. cholerae O139 strains were ctx (+)/zot (+). Rapid detection of the virulence genes (ctx and zot) can be achieved by PCR and this can serve as an important tool in the epidemiology and surveillance of V. cholerae.

Cholera ante portas - The re-emergence of cholera in Kinshasa after a ten-year hiatus.

PubMed

Bompangue, Didier; Vesenbeckh, Silvan Manuel; Giraudoux, Patrick; Castro, Marcia; Muyembe, Jean-Jacques; Kebela Ilunga, Benoît; Murray, Megan

2012-02-17

Cholera is an endemic disease in certain well-defined areas in the east of the Democratic Republic of Congo (DRC). The west of the country, including the mega-city Kinshasa, has been free of cases since mid 2001 when the last outbreak ended. We used routinely collected passive surveillance data to construct epidemic curves of the cholera cases and map the spatio-temporal progress of the disease during the first 47 weeks of 2011. We compared the spatial distribution of disease spread to that which occurred in the last cholera epidemic in Kinshasa between 1996 and 2001. To better understand previous determinants of cholera spread in this region, we conducted a correlation analysis to assess the impact of rainfall on weekly health zone cholera case counts between December 1998 and March 2001 and a Generalized Linear Model (GLM) regression analysis to identify factors that have been associated with the most vulnerable health zones within Kinshasa between October 1998 and June 1999. In February 2011, cholera reemerged in a region surrounding Kisangani and gradually spread westwards following the course of the Congo River to Kinshasa, home to 10 million people. Ten sampled isolates were confirmed to be Vibrio cholerae O1, biotype El Tor, serotype Inaba, resistant to trimethoprim-sulfa, furazolidone, nalidixic acid, sulfisoxaole, and streptomycin, and intermediate resistant to Chloramphenicol. An analysis of a previous outbreak in Kinshasa shows that rainfall was correlated with case counts and that health zone population densities as well as fishing and trade activities were predictors of case counts. Cholera is particularly difficult to tackle in the DRC. Given the duration of the rainy season and increased riverine traffic from the eastern provinces in late 2011, we expect further increases in cholera in the coming months and especially within the mega-city Kinshasa. We urge all partners involved in the response to remain alert.Didier Bompangue and Silvan Vesenbeckh

Hybrid microarray based on double biomolecular markers of DNA and carbohydrate for simultaneous genotypic and phenotypic detection of cholera toxin-producing Vibrio cholerae.

PubMed

Shin, Hwa Hui; Seo, Jeong Hyun; Kim, Chang Sup; Hwang, Byeong Hee; Cha, Hyung Joon

2016-05-15

Life-threatening diarrheal cholera is usually caused by water or food contaminated with cholera toxin-producing Vibrio cholerae. For the prevention and surveillance of cholera, it is crucial to rapidly and precisely detect and identify the etiological causes, such as V. cholerae and/or its toxin. In the present work, we propose the use of a hybrid double biomolecular marker (DBM) microarray containing 16S rRNA-based DNA capture probe to genotypically identify V. cholerae and GM1 pentasaccharide capture probe to phenotypically detect cholera toxin. We employed a simple sample preparation method to directly obtain genomic DNA and secreted cholera toxin as target materials from bacterial cells. By utilizing the constructed DBM microarray and prepared samples, V. cholerae and cholera toxin were detected successfully, selectively, and simultaneously; the DBM microarray was able to analyze the pathogenicity of the identified V. cholerae regardless of whether the bacteria produces toxin. Therefore, our proposed DBM microarray is a new effective platform for identifying bacteria and analyzing bacterial pathogenicity simultaneously. Copyright © 2015 Elsevier B.V. All rights reserved.

The HOG pathway controls osmotic regulation of transcription via the stress response element (STRE) of the Saccharomyces cerevisiae CTT1 gene.

PubMed Central

Schüller, C; Brewster, J L; Alexander, M R; Gustin, M C; Ruis, H

1994-01-01

The HOG signal pathway of the yeast Saccharomyces cerevisiae is defined by the PBS2 and HOG1 genes encoding members of the MAP kinase kinase and of the MAP kinase family, respectively. Mutations in this pathway (deletions of PBS2 or HOG1, or point mutations in HOG1) almost completely abolish the induction of transcription by osmotic stress that is mediated by stress response elements (STREs). We have demonstrated previously that STREs also mediate induction of transcription by heat shock, nitrogen starvation and oxidative stress. This study shows that they are also activated by low external pH, sorbate, benzoate or ethanol stress. Induction by these other stress signals appears to be HOG pathway independent. HOG1-dependent osmotic induction of transcription of the CTT1 gene encoding the cytosolic catalase T occurs in the presence of a protein synthesis inhibitor and can be detected rapidly after an increase of tyrosine phosphorylation of Hog1p triggered by high osmolarity. Consistent with a role of STREs in the induction of stress resistance, a number of other stress protein genes (e.g. HSP104) are regulated like CTT1. Furthermore, catalase T was shown to be important for viability under severe osmotic stress, and heat shock was demonstrated to provide cross-protection against osmotic stress. Images PMID:7523111

The HOG pathway controls osmotic regulation of transcription via the stress response element (STRE) of the Saccharomyces cerevisiae CTT1 gene.

PubMed

Schüller, C; Brewster, J L; Alexander, M R; Gustin, M C; Ruis, H

1994-09-15

The HOG signal pathway of the yeast Saccharomyces cerevisiae is defined by the PBS2 and HOG1 genes encoding members of the MAP kinase kinase and of the MAP kinase family, respectively. Mutations in this pathway (deletions of PBS2 or HOG1, or point mutations in HOG1) almost completely abolish the induction of transcription by osmotic stress that is mediated by stress response elements (STREs). We have demonstrated previously that STREs also mediate induction of transcription by heat shock, nitrogen starvation and oxidative stress. This study shows that they are also activated by low external pH, sorbate, benzoate or ethanol stress. Induction by these other stress signals appears to be HOG pathway independent. HOG1-dependent osmotic induction of transcription of the CTT1 gene encoding the cytosolic catalase T occurs in the presence of a protein synthesis inhibitor and can be detected rapidly after an increase of tyrosine phosphorylation of Hog1p triggered by high osmolarity. Consistent with a role of STREs in the induction of stress resistance, a number of other stress protein genes (e.g. HSP104) are regulated like CTT1. Furthermore, catalase T was shown to be important for viability under severe osmotic stress, and heat shock was demonstrated to provide cross-protection against osmotic stress.

In Vitro Inhibition of Cholera Toxin Production in Vibrio cholerae by Methanol Extract of Sweet Fennel Seeds and Its Components.

PubMed

Chatterjee, Shruti; Zahid, M Shamim Hasan; Awasthi, Sharda Prasad; Chowdhury, Nityananda; Asakura, Masahiro; Hinenoya, Atsushi; Ramamurthy, T; Iwaoka, Emiko; Aoki, Shunji; Yamasaki, Shinji

2016-09-21

A newly emerged Vibrio cholerae O1 El Tor variant strain with multidrug resistance is considered a threat to public health. Recent strategies to suppress virulence factors production instead of bacterial growth may lead to less selective pressure for the emergence of resistant strains. The use of spices and their active constituents as the inhibitory agents against cholera toxin (CT) production in V. cholerae may be an alternative approach to treat cholera. In this study, we examined the potential of sweet fennel seed (Foeniculum vulgare Miller var. dulce) methanol extract to inhibit CT production in V. cholerae without affecting viability. The methanol extract of sweet fennel seeds significantly inhibited CT production in various V. cholerae strains, regardless of serogroup or biotype. Interestingly, trans-anethole and 4-allylanisole, essential oil components of sweet fennel seeds, also demonstrated similar effects. Here, we report that sub-bactericidal concentrations of sweet fennel seed methanol extract and its major components can drastically inhibit CT production in various V. cholerae strains.

Fish as Reservoirs and Vectors of Vibrio cholerae

PubMed Central

Senderovich, Yigal; Izhaki, Ido; Halpern, Malka

2010-01-01

Vibrio cholerae, the etiologic agent of cholera, is autochthonous to various aquatic environments, but despite intensive efforts its ecology remains an enigma. Recently, it was suggested that copepods and chironomids, both considered as natural reservoirs of V. cholerae, are dispersed by migratory waterbirds, thus possibly distributing the bacteria between water bodies within and between continents. Although fish have been implicated in the scientific literature with cholera cases, as far as we know, no study actually surveyed the presence of the bacteria in the fish. Here we show for the first time that fish of various species and habitats contain V. cholerae in their digestive tract. Fish (n = 110) were randomly sampled from freshwater and marine habitats in Israel. Ten different fish species sampled from freshwater habitats (lake, rivers and fish ponds), and one marine species, were found to carry V. cholerae. The fish intestine of Sarotherodon galilaeus harboured ca. 5×103 V. cholerae cfu per 1 gr intestine content—high rates compared with known V. cholerae cfu numbers in the bacteria's natural reservoirs. Our results, combined with evidence from the literature, suggest that fish are reservoirs of V. cholerae. As fish carrying the bacteria swim from one location to another (some fish species move from rivers to lakes or sea and vice versa), they serve as vectors on a small scale. Nevertheless, fish are consumed by waterbirds, which disseminate the bacteria on a global scale. Moreover, V. cholerae isolates had the ability to degrade chitin, indicating a commensal relationship between V. cholerae and fish. Better understanding of V. cholerae ecology can help reduce the times that human beings come into contact with this pathogen and thus minimize the health risk this poses. PMID:20066040

Fish as reservoirs and vectors of Vibrio cholerae.

PubMed

Senderovich, Yigal; Izhaki, Ido; Halpern, Malka

2010-01-06

Vibrio cholerae, the etiologic agent of cholera, is autochthonous to various aquatic environments, but despite intensive efforts its ecology remains an enigma. Recently, it was suggested that copepods and chironomids, both considered as natural reservoirs of V. cholerae, are dispersed by migratory waterbirds, thus possibly distributing the bacteria between water bodies within and between continents. Although fish have been implicated in the scientific literature with cholera cases, as far as we know, no study actually surveyed the presence of the bacteria in the fish. Here we show for the first time that fish of various species and habitats contain V. cholerae in their digestive tract. Fish (n = 110) were randomly sampled from freshwater and marine habitats in Israel. Ten different fish species sampled from freshwater habitats (lake, rivers and fish ponds), and one marine species, were found to carry V. cholerae. The fish intestine of Sarotherodon galilaeus harboured ca. 5 x 10(3)V. cholerae cfu per 1 gr intestine content-high rates compared with known V. cholerae cfu numbers in the bacteria's natural reservoirs. Our results, combined with evidence from the literature, suggest that fish are reservoirs of V. cholerae. As fish carrying the bacteria swim from one location to another (some fish species move from rivers to lakes or sea and vice versa), they serve as vectors on a small scale. Nevertheless, fish are consumed by waterbirds, which disseminate the bacteria on a global scale. Moreover, V. cholerae isolates had the ability to degrade chitin, indicating a commensal relationship between V. cholerae and fish. Better understanding of V. cholerae ecology can help reduce the times that human beings come into contact with this pathogen and thus minimize the health risk this poses.

Updated Global Burden of Cholera in Endemic Countries

PubMed Central

Ali, Mohammad; Nelson, Allyson R.; Lopez, Anna Lena; Sack, David A.

2015-01-01

Background The global burden of cholera is largely unknown because the majority of cases are not reported. The low reporting can be attributed to limited capacity of epidemiological surveillance and laboratories, as well as social, political, and economic disincentives for reporting. We previously estimated 2.8 million cases and 91,000 deaths annually due to cholera in 51 endemic countries. A major limitation in our previous estimate was that the endemic and non-endemic countries were defined based on the countries’ reported cholera cases. We overcame the limitation with the use of a spatial modelling technique in defining endemic countries, and accordingly updated the estimates of the global burden of cholera. Methods/Principal Findings Countries were classified as cholera endemic, cholera non-endemic, or cholera-free based on whether a spatial regression model predicted an incidence rate over a certain threshold in at least three of five years (2008-2012). The at-risk populations were calculated for each country based on the percent of the country without sustainable access to improved sanitation facilities. Incidence rates from population-based published studies were used to calculate the estimated annual number of cases in endemic countries. The number of annual cholera deaths was calculated using inverse variance-weighted average case-fatality rate (CFRs) from literature-based CFR estimates. We found that approximately 1.3 billion people are at risk for cholera in endemic countries. An estimated 2.86 million cholera cases (uncertainty range: 1.3m-4.0m) occur annually in endemic countries. Among these cases, there are an estimated 95,000 deaths (uncertainty range: 21,000-143,000). Conclusion/Significance The global burden of cholera remains high. Sub-Saharan Africa accounts for the majority of this burden. Our findings can inform programmatic decision-making for cholera control. PMID:26043000

Toll-like receptor 2 is upregulated by hog confinement dust in an IL-6 dependent manner in the airway epithelium

PubMed Central

Bailey, KL; Poole, JA; Mathisen, TL; Wyatt, TA; Von Essen, SG; Romberger, DJ

2009-01-01

Hog confinement workers are at high risk to develop chronic bronchitis as a result of their exposure to organic dust. Chronic bronchitis is characterized by inflammatory changes of the airway epithelium. A key mediator in inflammation is Toll-like receptor 2 (TLR2). We investigated the role of TLR2 in pulmonary inflammation induced by hog confinement dust. Normal Human Bronchial Epithelial Cells (NHBE) were grown in culture and exposed to hog confinement dust extract. Hog confinement dust upregulated airway epithelial cell TLR2 mRNA in a concentration and time-dependent manner using real-time PCR. There was a similar increase in TLR2 protein at 48 hours as shown by Western blot. TLR2 was upregulated on the surface of airway epithelial cells as shown by flow cytometry. A similar upregulation of pulmonary TLR2 mRNA and protein was shown in a murine model of hog confinement dust exposure. Hog confinement dust is known to stimulate epithelial cells to produce IL-6. In order to determine whether TLR2 expression was being regulated by IL-6, the production of IL-6 was blocked using an IL-6 neutralizing antibody. This resulted in attenuation of the dust-induced upregulation of TLR2. To further demonstrate the importance of IL-6 in the regulation of TLR2, NHBE were directly stimulated with recombinant human IL-6. IL-6 alone was able to upregulate TLR2 in airway epithelial cells. Hog confinement dust upregulates TLR2 in the airway epithelium through an IL-6 dependent mechanism. PMID:18359883

Understanding the Hydrology of Cholera in South Asia

NASA Astrophysics Data System (ADS)

Akanda, A. S.; Jutla, A. S.; Islam, S.

2007-12-01

Cholera is an acute waterborne illness caused by the bacterium Vibrio cholerae. The disease remains a major public health issue in several regions of the developing world, mainly in coastal areas around the tropics. Cholera incidences have been historically linked to climate variables and more recently with El Nino-Southern Oscillation. The occurrence of cholera shows bi-annual seasonal peaks and strong inter-annual variability in the Ganges basin region of South Asia. However, the role of hydrologic variables in the seasonal patterns of cholera epidemics is less understood. Preliminary results suggest that a unique combination of increasing water temperature and higher salinity in the coastal zone during the low flow season provide the situation amenable to the first outbreak of cholera in the spring season. Other major factors contributing to the subsequent spread of the disease are sea surface height, monsoon precipitation, and coastal phytoplankton concentration. We will further examine the lag periods between the dominant environmental variables and cholera incidences to understand the seasonal dynamics of cholera in South Asia.

21 CFR 866.3930 - Vibrio cholerae serological reagents.

Code of Federal Regulations, 2014 CFR

2014-04-01

... cholera caused by the bacterium Vibrio cholerae and provides epidemiological information on cholera... (salts) depletion, and by vomiting, muscle cramps, and prostration. If untreated, the severe dehydration...

21 CFR 866.3930 - Vibrio cholerae serological reagents.

Code of Federal Regulations, 2012 CFR

2012-04-01

... cholera caused by the bacterium Vibrio cholerae and provides epidemiological information on cholera... (salts) depletion, and by vomiting, muscle cramps, and prostration. If untreated, the severe dehydration...

21 CFR 866.3930 - Vibrio cholerae serological reagents.

Code of Federal Regulations, 2013 CFR

2013-04-01

... cholera caused by the bacterium Vibrio cholerae and provides epidemiological information on cholera... (salts) depletion, and by vomiting, muscle cramps, and prostration. If untreated, the severe dehydration...

The Burden of Cholera in Uganda

PubMed Central

Bwire, Godfrey; Malimbo, Mugagga; Maskery, Brian; Kim, Young Eun; Mogasale, Vittal; Levin, Ann

2013-01-01

Introduction In 2010, the World Health Organization released a new cholera vaccine position paper, which recommended the use of cholera vaccines in high-risk endemic areas. However, there is a paucity of data on the burden of cholera in endemic countries. This article reviewed available cholera surveillance data from Uganda and assessed the sufficiency of these data to inform country-specific strategies for cholera vaccination. Methods The Uganda Ministry of Health conducts cholera surveillance to guide cholera outbreak control activities. This includes reporting the number of cases based on a standardized clinical definition plus systematic laboratory testing of stool samples from suspected cases at the outset and conclusion of outbreaks. This retrospective study analyzes available data by district and by age to estimate incidence rates. Since surveillance activities focus on more severe hospitalized cases and deaths, a sensitivity analysis was conducted to estimate the number of non-severe cases and unrecognized deaths that may not have been captured. Results Cholera affected all ages, but the geographic distribution of the disease was very heterogeneous in Uganda. We estimated that an average of about 11,000 cholera cases occurred in Uganda each year, which led to approximately 61–182 deaths. The majority of these cases (81%) occurred in a relatively small number of districts comprising just 24% of Uganda's total population. These districts included rural areas bordering the Democratic Republic of Congo, South Sudan, and Kenya as well as the slums of Kampala city. When outbreaks occurred, the average duration was about 15 weeks with a range of 4–44 weeks. Discussion There is a clear subdivision between high-risk and low-risk districts in Uganda. Vaccination efforts should be focused on the high-risk population. However, enhanced or sentinel surveillance activities should be undertaken to better quantify the endemic disease burden and high-risk populations

Drug response and genetic properties of Vibrio cholerae associated with endemic cholera in north-eastern Thailand, 2003–2011

PubMed Central

Chomvarin, Chariya; Johura, Fatema-Tuz; Mannan, Shahnewaj B.; Jumroenjit, Warin; Kanoktippornchai, Boonnapa; Tangkanakul, Waraluk; Tantisuwichwong, Napaporn; Huttayananont, Sriwanna; Watanabe, Haruo; Hasan, Nur A.; Huq, Anwar; Cravioto, Alejandro; Colwell, Rita R.

2013-01-01

Cholera, caused by Vibrio cholerae, results in significant morbidity and mortality worldwide, including Thailand. Representative V. cholerae strains associated with endemic cholera (n = 32), including strains (n = 3) from surface water sources, in Khon Kaen, Thailand (2003–2011), were subjected to microbiological, molecular and phylogenetic analyses. According to phenotypic and related genetic data, all tested V. cholerae strains belonged to serogroup O1, biotype El Tor (ET), Inaba (IN) or Ogawa (OG). All of the strains were sensitive to gentamicin and ciprofloxacin, while multidrug-resistant (MDR) strains showing resistance to erythromycin, tetracycline, trimethoprim/sulfamethoxazole and ampicillin were predominant in 2007. V. cholerae strains isolated before and after 2007 were non-MDR. All except six diarrhoeal strains possessed ctxA and ctxB genes and were toxigenic altered ET, confirmed by MAMA-PCR and DNA sequencing. Year-wise data revealed that V. cholerae INET strains isolated between 2003 and 2004, plus one strain isolated in 2007, lacked the RS1 sequence (rstC) and toxin-linked cryptic plasmid (TLC)-specific genetic marker, but possessed CTXCL prophage genes ctxBCL and rstRCL. A sharp genetic transition was noted, namely the majority of V. cholerae strains in 2007 and all in 2010 and 2011 were not repressor genotype rstRCL but instead were rstRET, and all ctx+ strains possessed RS1 and TLC-specific genetic markers. DNA sequencing data revealed that strains isolated since 2007 had a mutation in the tcpA gene at amino acid position 64 (N→S). Four clonal types, mostly of environmental origin, including subtypes, reflected genetic diversity, while distinct signatures were observed for clonally related, altered ET from Thailand, Vietnam and Bangladesh, confirmed by distinct subclustering patterns observed in the PFGE (NotI)-based dendrogram, suggesting that endemic cholera is caused by V. cholerae indigenous to Khon Kaen. PMID:23319310

Epidemic risk from cholera introductions into Mexico.

PubMed

Moore, Sean M; Shannon, Kerry L; Zelaya, Carla E; Azman, Andrew S; Lessler, Justin

2014-02-21

Stemming from the 2010 cholera outbreak in Haiti, cholera transmission in Hispaniola continues with over 40,000 cases in 2013. The presence of an ongoing cholera outbreak in the region poses substantial risks to countries throughout the Americas, particularly in areas with poor infrastructure. Since September 9, 2013 nearly 200 cholera cases have been reported in Mexico, as a result of introductions from Hispaniola or Cuba. There appear to have been multiple introductions into Mexico resulting in outbreaks of 2 to over 150 people. Using publicly available data, we attempt to estimate the reproductive number (R) of cholera in Mexico, and thereby assess the potential of continued introductions to establish a sustained epidemic. We estimate R for cholera in Mexico to be between 0.8 to 1.1, depending on the number of introductions, with the confidence intervals for the most plausible estimates crossing 1. These results suggest that the efficiency of cholera transmission in some regions of Mexico is near that necessary for a large epidemic. Intensive surveillance, evaluation of water and sanitation infrastructure, and planning for rapid response are warranted steps to avoid potential large epidemics in the region.

Impact of Drainage Networks on Cholera Outbreaks in Lusaka, Zambia

PubMed Central

Suzuki, Hiroshi; Fujino, Yasuyuki; Kimura, Yoshinari; Cheelo, Meetwell

2009-01-01

Objectives. We investigated the association between precipitation patterns and cholera outbreaks and the preventative roles of drainage networks against outbreaks in Lusaka, Zambia. Methods. We collected data on 6542 registered cholera patients in the 2003–2004 outbreak season and on 6045 cholera patients in the 2005–2006 season. Correlations between monthly cholera incidences and amount of precipitation were examined. The distribution pattern of the disease was analyzed by a kriging spatial analysis method. We analyzed cholera case distribution and spatiotemporal cluster by using 2590 cholera cases traced with a global positioning system in the 2005–2006 season. The association between drainage networks and cholera cases was analyzed with regression analysis. Results. Increased precipitation was associated with the occurrence of cholera outbreaks, and insufficient drainage networks were statistically associated with cholera incidences. Conclusions. Insufficient coverage of drainage networks elevated the risk of cholera outbreaks. Integrated development is required to upgrade high-risk areas with sufficient infrastructure for a long-term cholera prevention strategy. PMID:19762668

Costs of Illness Due to Endemic Cholera

PubMed Central

Poulos, C.; Riewpaiboon, A.; Stewart, J.F.; Clemens, J.; Guh, S.; Agtini, M.; Sur, D.; Islam, Z.; Lucas, M.; Whittington, D.

2013-01-01

Summary Economic analyses of cholera immunization programmes require estimates of the costs of cholera. The Diseases of the Most Impoverished programme measured the public, provider, and patient costs of culture-confirmed cholera in four study sites with endemic cholera using a combination of hospital- and community-based studies. Families with culture-proven cases were surveyed at home 7 and 14 days after confirmation of illness. Public costs were measured at local health facilities using a micro-costing methodology. Hospital-based studies found that the costs of severe cholera were USD 32 and 47 in Matlab and Beira. Community-based studies in North Jakarta and Kolkata found that cholera cases cost between USD 28 and USD 206, depending on hospitalization. Patient costs of illness as a percentage of average monthly income were 21% and 65% for hospitalized cases in Kolkata and North Jakarta, respectively. This burden on families is not captured by studies that adopt a provider perspective. PMID:21554781

Persistence of plasmids, cholera toxin genes, and prophage DNA in classical Vibrio cholerae O1.

PubMed

Cook, W L; Wachsmuth, K; Johnson, S R; Birkness, K A; Samadi, A R

1984-07-01

Plasmid profiles, the location of cholera toxin subunit A genes, and the presence of the defective VcA1 prophage genome in classical Vibrio cholerae isolated from patients in Bangladesh in 1982 were compared with those in older classical strains isolated during the sixth pandemic and with those in selected eltor and nontoxigenic O1 isolates. Classical strains typically had two plasmids (21 and 3 megadaltons), eltor strains typically had no plasmids, and nontoxigenic O1 strains had zero to three plasmids. The old and new isolates of classical V. cholerae had two HindIII chromosomal digest fragments containing cholera toxin subunit A genes, whereas the eltor strains from Eastern countries had one fragment. The eltor strains from areas surrounding the Gulf of Mexico also had two subunit A gene fragments, which were smaller and easily distinguished from the classical pattern. All classical strains had 8 to 10 HindIII fragments containing the defective VcA1 prophage genome; none of the Eastern eltor strains had these genes, and the Gulf Coast eltor strains contained a different array of weakly hybridizing genes. These data suggest that the recent isolates of classical cholera in Bangladesh are closely related to the bacterial strain(s) which caused classical cholera during the sixth pandemic. These data do not support hypotheses that either the eltor or the nontoxigenic O1 strains are precursors of the new classical strains.

Cholera ante portas – The re-emergence of cholera in Kinshasa after a ten-year hiatus

PubMed Central

Bompangue, Didier; Vesenbeckh, Silvan Manuel; Giraudoux, Patrick; Castro, Marcia; Muyembe, Jean-Jacques; Kebela Ilunga, Benoît; Murray, Megan

2012-01-01

Background: Cholera is an endemic disease in certain well-defined areas in the east of the Democratic Republic of Congo (DRC). The west of the country, including the mega-city Kinshasa, has been free of cases since mid 2001 when the last outbreak ended. Methods and Findings: We used routinely collected passive surveillance data to construct epidemic curves of the cholera cases and map the spatio-temporal progress of the disease during the first 47 weeks of 2011. We compared the spatial distribution of disease spread to that which occurred in the last cholera epidemic in Kinshasa between 1996 and 2001. To better understand previous determinants of cholera spread in this region, we conducted a correlation analysis to assess the impact of rainfall on weekly health zone cholera case counts between December 1998 and March 2001 and a Generalized Linear Model (GLM) regression analysis to identify factors that have been associated with the most vulnerable health zones within Kinshasa between October 1998 and June 1999. In February 2011, cholera reemerged in a region surrounding Kisangani and gradually spread westwards following the course of the Congo River to Kinshasa, home to 10 million people. Ten sampled isolates were confirmed to be Vibrio cholerae O1, biotype El Tor, serotype Inaba, resistant to trimethoprim-sulfa, furazolidone, nalidixic acid, sulfisoxaole, and streptomycin, and intermediate resistant to Chloramphenicol. An analysis of a previous outbreak in Kinshasa shows that rainfall was correlated with case counts and that health zone population densities as well as fishing and trade activities were predictors of case counts. Conclusion: Cholera is particularly difficult to tackle in the DRC. Given the duration of the rainy season and increased riverine traffic from the eastern provinces in late 2011, we expect further increases in cholera in the coming months and especially within the mega-city Kinshasa. We urge all partners involved in the response to remain

Hydroquinone, a benzene metabolite, induces Hog1-dependent stress response signaling and causes aneuploidy in Saccharomyces cerevisiae.

PubMed

Shiga, Takeki; Suzuki, Hiroyuki; Yamamoto, Ayumi; Yamamoto, Hiroaki; Yamamoto, Kazuo

2010-01-01

Previously, we have shown that phenyl hydroquinone, a hepatic metabolite of the Ames test-negative carcinogen o-phenylphenol, efficiently induced aneuploidy in Saccharomyces cerevisiae by arresting the cell cycle at the G2/M transition as a result of the activation of the Hog1 (p38 MAPK homolog)-Swe1 (Wee1 homolog) pathway. In this experiment, we examined the aneuploidy forming effects of hydroquinone, a benzene metabolite, since both phenyl hydroquinone and hydroquinone are Ames-test negative carcinogens and share similar molecular structures. As was seen in phenyl hydroquinone, hydroquinone induced aneuploidy in yeast by delaying the cell cycle at the G2/M transition. Deficiencies in SWE1 and HOG1 abolished the hydroquinone-induced delay at the G2/M transition and aneuploidy formation. Furthermore, Hog1 was phosphorylated by hydroquinone, which may stabilize Swe1. These data indicate that the hydroquinone-induced G2/M transition checkpoint, which is activated by the Hog1-Swe1 pathway, plays a role in the formation of aneuploidy.

Crystallization of isoelectrically homogeneous cholera toxin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spangler, B.D.; Westbrook, E.M.

1989-02-07

Past difficulty in growing good crystals of cholera toxin has prevented the study of the crystal structure of this important protein. The authors have determined that failure of cholera toxin to crystallize well has been due to its heterogeneity. They have now succeeded in overcoming the problem by isolating a single isoelectric variant of this oligomeric protein (one A subunit and five B subunits). Cholera toxin purified by their procedure readily forms large single crystals. The crystal form has been described previously. They have recorded data from native crystals of cholera toxin to 3.0-{angstrom} resolution with our electronic area detectors.more » With these data, they have found the orientation of a 5-fold symmetry axis within these crystals, perpendicular to the screw dyad of the crystal. They are now determining the crystal structure of cholera toxin by a combination of multiple heavy-atom isomorphous replacement and density modification techniques, making use of rotational 5-fold averaging of the B subunits.« less

Characterization of highly virulent multidrug resistant Vibrio cholerae isolated from a large cholera outbreak in Ghana.

PubMed

Feglo, Patrick Kwame; Sewurah, Miriam

2018-01-18

The purpose of this study was to investigate the virulent factors of Vibrio cholerae which caused an unprecedented large cholera outbreak in Ghana in 2014 and progressed into 2015, affected 28,975 people with 243 deaths. The V. cholerae isolates were identified to be the classical V. cholerae 01 biotype El Tor, serotype Ogawa, responsible for the large cholera outbreak in Ghana. These El Tor strains bear CtxAB and Tcp virulent genes, making the strains highly virulent. The strains also bear SXT transmissible element coding their resistance to antibiotics, causing high proportions of the strains to be multidrug resistant, with resistant proportions of 95, 90 and 75% to trimethoprim/sulfamethoxazole, ampicillin and ceftriaxone respectively. PFGE patterns indicated that the isolates clustered together with the same pattern and showed clusters similar to strains circulating in DR Congo, Cameroun, Ivory Coast and Togo. The strains carried virulence genes which facilitated the disease causation and spread. This is the first time these virulent genes were determined on the Ghanaian Vibrio strains.

Integrated view of Vibrio cholerae in the Americas.

PubMed

Domman, Daryl; Quilici, Marie-Laure; Dorman, Matthew J; Njamkepo, Elisabeth; Mutreja, Ankur; Mather, Alison E; Delgado, Gabriella; Morales-Espinosa, Rosario; Grimont, Patrick A D; Lizárraga-Partida, Marcial Leonardo; Bouchier, Christiane; Aanensen, David M; Kuri-Morales, Pablo; Tarr, Cheryl L; Dougan, Gordon; Parkhill, Julian; Campos, Josefina; Cravioto, Alejandro; Weill, François-Xavier; Thomson, Nicholas R

2017-11-10

Latin America has experienced two of the largest cholera epidemics in modern history; one in 1991 and the other in 2010. However, confusion still surrounds the relationships between globally circulating pandemic Vibrio cholerae clones and local bacterial populations. We used whole-genome sequencing to characterize cholera across the Americas over a 40-year time span. We found that both epidemics were the result of intercontinental introductions of seventh pandemic El Tor V. cholerae and that at least seven lineages local to the Americas are associated with disease that differs epidemiologically from epidemic cholera. Our results consolidate historical accounts of pandemic cholera with data to show the importance of local lineages, presenting an integrated view of cholera that is important to the design of future disease control strategies. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Use of passive samplers to measure atmospheric ammonia levels in a high-density industrial hog farm area of eastern North Carolina

NASA Astrophysics Data System (ADS)

Wilson, Sacoby M.; Serre, Marc L.

Hog concentrated animal feeding operations (CAFOs) in North Carolina release ammonia (NH 3), hydrogen sulfide, VOCs, and particulate matter to the atmosphere. These operations are located mainly in the NC coastal plain and can create potential health hazards for nearby human populations. Limited work has been performed to measure NH 3 at the community level to assess potential human exposure. In an effort to address this issue, a study was designed to measure NH 3 levels near hog CAFOs and community locations (i.e. homes and schools) in Eastern NC. NH 3 was collected using passive diffusion tubes in triplicate exposed primarily in weekly intervals. Sampling occurred from October 2003 to May 2004 (20 sites) and from July 2004 to October 2004 (23 sites) at varying distances from hog CAFOs in close proximity to homes and schools. Average weekly NH3 levels were measured as mass (μg NH 3-N) and converted to concentration (ppb). Mean level of 13.8 ppb near homes and schools (<2 km) was 4-12 times greater than ambient background levels (1-3 ppb), reaching as high as 80 ppb. Exposed sites (<2 km from a hog CAFO) had a mean level of 12.8 ppb which was over 2 times higher than the mean level of 5.5 ppb at less exposed sites (>2 km from a hog CAFO). The study establishes that passive sampling can be effectively used to measure average atmospheric ammonia levels at community locations near hog CAFOs in Eastern NC. The collected data indicate the relative exposure for human populations who live near a hog CAFO. The closer a populace is to the hog CAFO, the more intense the exposure. These results require more validation in the field by comparison to a reference method.

Riverbed Sediments as Reservoirs of Multiple Vibrio cholerae Virulence-Associated Genes: A Potential Trigger for Cholera Outbreaks in Developing Countries.

PubMed

Abia, Akebe Luther King; Ubomba-Jaswa, Eunice; Momba, Maggy Ndombo Benteke

2017-01-01

Africa remains the most cholera stricken continent in the world as many people lacking access to safe drinking water rely mostly on polluted rivers as their main water sources. However, studies in these countries investigating the presence of Vibrio cholerae in aquatic environments have paid little attention to bed sediments. Also, information on the presence of virulence-associated genes (VAGs) in environmental ctx -negative V. cholerae strains in this region is lacking. Thus, we investigated the presence of V. cholerae VAGs in water and riverbed sediment of the Apies River, South Africa. Altogether, 120 samples (60 water and 60 sediment samples) collected from ten sites on the river (January and February 2014) were analysed using PCR. Of the 120 samples, 37 sediment and 31 water samples were positive for at least one of the genes investigated. The haemolysin gene (hlyA) was the most isolated gene. The cholera toxin (ctxAB) and non-O1 heat-stable (stn/sto) genes were not detected. Genes were frequently detected at sites influenced by human activities. Thus, identification of V. cholerae VAGs in sediments suggests the possible presence of V. cholerae and identifies sediments of the Apies River as a reservoir for potentially pathogenic V. cholerae with possible public health implications.

Human Gut Microbiota Predicts Susceptibility to Vibrio cholerae Infection.

PubMed

Midani, Firas S; Weil, Ana A; Chowdhury, Fahima; Begum, Yasmin A; Khan, Ashraful I; Debela, Meti D; Durand, Heather K; Reese, Aspen T; Nimmagadda, Sai N; Silverman, Justin D; Ellis, Crystal N; Ryan, Edward T; Calderwood, Stephen B; Harris, Jason B; Qadri, Firdausi; David, Lawrence A; LaRocque, Regina C

2018-04-12

Cholera is a public health problem worldwide and the risk factors for infection are only partially understood. We prospectively studied household contacts of cholera patients to compare those who were infected with those who were not. We constructed predictive machine learning models of susceptibility using baseline gut microbiota data. We identified bacterial taxa associated with susceptibility to Vibrio cholerae infection and tested these taxa for interactions with V. cholerae in vitro. We found that machine learning models based on gut microbiota predicted V. cholerae infection as well as models based on known clinical and epidemiological risk factors. A 'predictive gut microbiota' of roughly 100 bacterial taxa discriminated between contacts who developed infection and those who did not. Susceptibility to cholera was associated with depleted levels of microbes from the phylum Bacteroidetes. By contrast, a microbe associated with cholera by our modeling framework, Paracoccus aminovorans, promoted the in vitro growth of V. cholerae. Gut microbiota structure, clinical outcome, and age were also linked. These findings support the hypothesis that abnormal gut microbial communities are a host factor related to V. cholerae susceptibility.

Ship detection based on rotation-invariant HOG descriptors for airborne infrared images

NASA Astrophysics Data System (ADS)

Xu, Guojing; Wang, Jinyan; Qi, Shengxiang

2018-03-01

Infrared thermal imagery is widely used in various kinds of aircraft because of its all-time application. Meanwhile, detecting ships from infrared images attract lots of research interests in recent years. In the case of downward-looking infrared imagery, in order to overcome the uncertainty of target imaging attitude due to the unknown position relationship between the aircraft and the target, we propose a new infrared ship detection method which integrates rotation invariant gradient direction histogram (Circle Histogram of Oriented Gradient, C-HOG) descriptors and the support vector machine (SVM) classifier. In details, the proposed method uses HOG descriptors to express the local feature of infrared images to adapt to changes in illumination and to overcome sea clutter effects. Different from traditional computation of HOG descriptor, we subdivide the image into annular spatial bins instead of rectangle sub-regions, and then Radial Gradient Transform (RGT) on the gradient is applied to achieve rotation invariant histogram information. Considering the engineering application of airborne and real-time requirements, we use SVM for training ship target and non-target background infrared sample images to discriminate real ships from false targets. Experimental results show that the proposed method has good performance in both the robustness and run-time for infrared ship target detection with different rotation angles.

Factors associated with cholera in Kenya, 2008-2013

PubMed Central

Cowman, Gretchen; Otipo, Shikanga; Njeru, Ian; Achia, Thomas; Thirumurthy, Harsha; Bartram, Jamie; Kioko, Jackson

2017-01-01

Introduction Kenya experienced widespread cholera outbreaks in 1997-1999 and 2007-2010. The re-emergence of cholera in Kenya in 2015 indicates that cholera remains a public health threat. Understanding past outbreaks is important for preventing future outbreaks. This study investigated the relationship between cholera occurrence in Kenya and various environmental and demographic factors related to water, sanitation, socio-economic status, education, urbanization and availability of health facilities during the time period 2008-2013. Methods The primary outcome analyzed was the number of cholera cases at the district level, obtained from the Kenya Ministry of Health's national cholera surveillance records. Values of independent variables were obtained from the 2009 Kenya Population and Housing Census and other national surveys. The data were analyzed using a zero-inflated negative binomial regression model. Results Multivariate analysis indicated that the risk of cholera was associated with open defecation, use of unimproved water sources, poverty headcount ratio and the number of health facilities per 100,000 population (p < 0.05). No statistically significant association was found between cholera occurrence and education, percentage of population living in urban areas or population density. Conclusion The Sustainable Development Goals and Kenya's blueprint for development, Kenya Vision 2030, call for access to sanitation facilities and clean water for all by 2030. Kenya has made important economic strides in recent years but continues to be affected by diseases like cholera that are associated with low socio-economic status. Further expansion of access to sanitation facilities and clean water is necessary for preventing cholera in Kenya. PMID:29515719

Factors associated with cholera in Kenya, 2008-2013.

PubMed

Cowman, Gretchen; Otipo, Shikanga; Njeru, Ian; Achia, Thomas; Thirumurthy, Harsha; Bartram, Jamie; Kioko, Jackson

2017-01-01

Kenya experienced widespread cholera outbreaks in 1997-1999 and 2007-2010. The re-emergence of cholera in Kenya in 2015 indicates that cholera remains a public health threat. Understanding past outbreaks is important for preventing future outbreaks. This study investigated the relationship between cholera occurrence in Kenya and various environmental and demographic factors related to water, sanitation, socio-economic status, education, urbanization and availability of health facilities during the time period 2008-2013. The primary outcome analyzed was the number of cholera cases at the district level, obtained from the Kenya Ministry of Health's national cholera surveillance records. Values of independent variables were obtained from the 2009 Kenya Population and Housing Census and other national surveys. The data were analyzed using a zero-inflated negative binomial regression model. Multivariate analysis indicated that the risk of cholera was associated with open defecation, use of unimproved water sources, poverty headcount ratio and the number of health facilities per 100,000 population (p < 0.05). No statistically significant association was found between cholera occurrence and education, percentage of population living in urban areas or population density. The Sustainable Development Goals and Kenya's blueprint for development, Kenya Vision 2030 , call for access to sanitation facilities and clean water for all by 2030. Kenya has made important economic strides in recent years but continues to be affected by diseases like cholera that are associated with low socio-economic status. Further expansion of access to sanitation facilities and clean water is necessary for preventing cholera in Kenya.

Effectiveness of an oral cholera vaccine campaign to prevent clinically-significant cholera in Odisha State, India.

PubMed

Wierzba, Thomas F; Kar, Shantanu K; Mogasale, Vijayalaxmi V; Kerketta, Anna S; You, Young Ae; Baral, Prameela; Khuntia, Hemant K; Ali, Mohammad; Kim, Yang Hee; Rath, Shyam Bandhu; Bhattachan, Anuj; Sah, Binod

2015-05-15

A clinical trial conducted in India suggests that the oral cholera vaccine, Shanchol, provides 65% protection over five years against clinically-significant cholera. Although the vaccine is efficacious when tested in an experimental setting, policymakers are more likely to use this vaccine after receiving evidence demonstrating protection when delivered to communities using local health department staff, cold chain equipment, and logistics. We used a test-negative, case-control design to evaluate the effectiveness of a vaccination campaign using Shanchol and validated the results using a cohort approach that addressed disparities in healthcare seeking behavior. The campaign was conducted by the local health department using existing resources in a cholera-endemic area of Puri District, Odisha State, India. All non-pregnant residents one year of age and older were offered vaccine. Over the next two years, residents seeking care for diarrhea at one of five health facilities were asked to enroll following informed consent. Cases were patients seeking treatment for laboratory-confirmed V. cholera-associated diarrhea. Controls were patients seeking treatment for V. cholerae negative diarrhea. Of 51,488 eligible residents, 31,552 individuals received one dose and 23,751 residents received two vaccine doses. We identified 44 V. cholerae O1-associated cases and 366 non V. cholerae diarrhea controls. The adjusted protective effectiveness for persons receiving two doses was 69.0% (95% CI: 14.5% to 88.8%), which is similar to the adjusted estimates obtained from the cohort approach. A statistical trend test suggested a single dose provided a modicum of protection (33%, test for trend, p=0.0091). This vaccine was found to be as efficacious as the results reported from a clinical trial when administered to a rural population using local health personnel and resources. This study provides evidence that this vaccine should be widely deployed by public health departments in

Cholera: an overview with reference to the Yemen epidemic.

PubMed

Rabaan, Ali A

2018-06-22

Cholera is a secretory diarrhoeal disease caused by infection with Vibrio cholerae, primarily the V. cholerae O1 El Tor biotype. There are approximately 2.9 million cases in 69 endemic countries annually, resulting in 95 000 deaths. Cholera is associated with poor infrastructure and lack of access to sanitation and clean drinking water. The current cholera epidemic in Yemen, linked to spread of V. cholerae O1 (Ogawa serotype), is associated with the ongoing war. This has devastated infrastructure and health services. The World Health Organization had estimated that 172 286 suspected cases arose between 27th April and 19th June 2017, including 1170 deaths. While there are three oral cholera vaccines prequalified by the World Health Organization, there are issues surrounding vaccination campaigns in conflict situations, exacerbated by external factors such as a global vaccine shortage. Major movements of people complicates surveillance and administration of double doses of vaccines. Cholera therapy mainly depends on rehydration, with use of antibiotics in more severe infections. Concerns have arisen about the rise of antibiotic resistance in cholera, due to mobile genetic elements. In this review, we give an overview of cholera epidemiology, virulence, antibiotic resistance, therapy and vaccines, in the light of the ongoing epidemic in Yemen.

In vitro growth of Vibrio cholerae in cholera stool fluid leads to differential expression of virulence factors.

PubMed

Sánchez, J; Castillo, G; Medrano, A I; Martinez-Palomo, A; Rodríguez, M H

1995-01-01

We report on the physiological response of Vibrio cholerae upon growth on bacteria-free intestinal fluids prepared from feces of individuals in the acute phase of cholera. Sterilized stool fluids supported growth of V. cholerae to reach 0.3-0.4 O.D. units (600 nm) at 37 degrees C. Scanning electron microscopy showed vibrios to be slender and elongated as compared to bacteria in synthetic media. Growth in stool fluid apparently induced expression of several immunoreactive proteins using cholera convalescent sera. Supernatants of fluid-grown vibrios had undetectable cholera toxin (CT) concentrations. Soluble hemagglutinins and soluble proteases were much less reduced when compared to cultures in Syncase or AKI media while cell-associated mannose-sensitive hemagglutinin (MSHA) was expressed at good levels. Lack of production of CT in fluid devoid of tissue may be due to absence of stimulating elements in intact intestine. Alternatively, culturing V. cholerae in stool fluid might resemble a late proliferation stage where downregulation of toxin might occur. Irrespectively, concomitant production of other virulence factors represents a phenomenon of differential regulation by fluid. Efforts are now underway to determine if this response depends upon factors in stool fluid acting through known genetic regulatory cascades or other. Attempts are also geared to identify fluid-induced proteins and their genes.

An evolutionarily stable strategy and the critical point of hog futures trading entities based on replicator dynamic theory: 2006-2015 data for China's 22 provinces.

PubMed

Pang, Jinbo; Deng, Lingfei; Wang, Gangyi

2017-01-01

Although frequent fluctuations in domestic hog prices seriously affect the stability and robustness of the hog supply chain, hog futures (an effective hedging instrument) have not been listed in China. To better understand hog futures market hedging, it is important to study the steady state of intersubjective bidding. This paper uses evolutionary game theory to construct a game model between hedgers and speculators in the hog futures market, and replicator dynamic equations are then used to obtain the steady state between the two trading entities. The results show that the steady state is one in which hedgers adopt a "buy" strategy and speculators adopt a "do not speculate" strategy, but this type of extreme steady state is not easily realized. Thus, to explore the rational proportion of hedgers and speculators in the evolutionary stabilization strategy, bidding processes were simulated using weekly average hog prices from 2006 to 2015, such that the conditions under which hedgers and speculators achieve a steady state could be analyzed. This task was performed to achieve the stability critical point, and we show that only when the value of λ is satisfied and the conditions of hog futures price changes and futures price are satisfied can hedgers and speculators achieve a rational proportion and a stable hog futures market. This market can thus provide a valuable reference for the development of the Chinese hog futures market and the formulation and guidance of relevant departmental policies.

Cholera on a Gulf Coast oil rig.

PubMed

Johnston, J M; Martin, D L; Perdue, J; McFarland, L M; Caraway, C T; Lippy, E C; Blake, P A

1983-09-01

A single case of severe diarrhea on a floating Texas oil rig was followed two days later by what proved to be the largest outbreak of cholera in the United States in over a century. After isolation of toxigenic Vibrio cholerae El Tor Inaba of the typical United States phage type from the index patient's stool, the ensuing investigation detected 14 additional cases of cholera and one asymptomatic infection serologically. Infection was associated with eating rice on the oil rig on a particular day (P = 0.03) when an open valve permitted the rig's drinking-water system to be contaminated by canal water containing sewage (including that from the index patient) discharged from the rig. The rice had been rinsed in the contaminated water after cooking, and before being served it had been maintained at a temperature that allows V. cholerae 01 to multiply. Toxigenic V. cholerae 01 is persisting in the United States, and large common-source outbreaks of cholera can occur if proper sanitation is not maintained.

Efficacy of Ciprofloxacin for Treatment of Cholera Associated with Diminished Susceptibility to Ciprofloxacin to Vibrio cholerae O1.

PubMed

Khan, Wasif Ali; Saha, Debasish; Ahmed, Sabeena; Salam, Mohammed Abdus; Bennish, Michael Louis

2015-01-01

We identified a poor clinical response to treatment of cholera with a single 1 g dose of ciprofloxacin, a standard treatment for cholera. To determine reasons for the poor response and better therapeutic approaches we examined the minimal inhibitor concentration (MIC, n = 275) and disc-diffusion zone sizes (n = 205) for ciprofloxacin and nalidixic acid of V. cholerae O1 strains isolated in Bangladesh from 1994 to 2012, and reexamined data from 161 patients infected with Vibrio cholerae O1 recruited in four clinical trials who received single- or multiple-dose ciprofloxacin for treatment of cholera and compared their clinical response to the V. cholerae O1 susceptibility. Although all 275 isolates of V. cholerae O1 remained susceptible to ciprofloxacin using standard MIC and disc-diffusion thresholds, the MIC90 to ciprofloxacin increased from 0.010 in 1994 to 0.475 μgm/ml in 2012. Isolates became frankly resistant to nalidixic with the MIC90 increasing from 21 μgm/ml in 1994 to >256 μgm/ml and 166 of 205 isolates from 1994 to 2005 being frankly resistant using disc-diffusion testing. Isolates resistant to nalidixic acid by disc-diffusion testing had a median ciprofloxacin MIC of 0.190 μgm/ml (10th-90th centiles 0.022 to 0.380); nalidixic acid-susceptible isolates had a median ciprofloxacin MIC of 0.002 (0.002 to 0.012).The rate of clinical success with single-dose ciprofloxacin treatment for nalidixic acid-susceptible strains was 94% (61 of 65 patients) and bacteriologic success 97% (63/65) compared to 18% (12/67) and 8% (5/67) respectively with nalidixic acid-resistant strains (P<0.001 for both comparisons). Multiple-dose treatment with ciprofloxacin had 86% and 100% clinical and bacteriologic success rates respectively in patients infected with nalidixic acid-susceptible strains of V. cholerae O1 compared to clinical success 67% and bacteriologic success 60% with nalidixic acid-resistant strains. Single-dose ciprofloxacin is not effective for treating cholera

Numerical taxonomy of Vibrio cholerae and related species isolated from areas that are endemic and nonendemic for cholera.

PubMed Central

McNicol, L A; De, S P; Kaper, J B; West, P A; Colwell, R R

1983-01-01

A total of 165 strains of vibrios isolated from clinical and environmental sources in the United States, India, and Bangladesh, 11 reference cultures, and 4 duplicated cultures were compared in a numerical taxonomic study using 83 unit characters. Similarity between strains was computed by using the simple matching coefficient and the Jaccard coefficient. Strains were clustered by unweighted average linkage and single linkage algorithms. All methods gave similar cluster compositions. The estimated probability of error in the study was obtained from a comparison of the results of duplicated strains and was within acceptable limits. A total of 174 of the 180 organisms studied were divided into eight major clusters. Two clusters were identified as Vibrio cholerae, one as Vibrio mimicus, one as Vibrio parahaemolyticus, three as Vibrio species, and one as Aeromonas hydrophila. The V. mimicus cluster could be further divided into two subclusters, and the major V. cholerae group could be split into seven minor subclusters. Phenotypic traits routinely used to identify clinical isolates of V. cholerae can be used to identify environmental V. cholerae isolates. No distinction was found between strains of V. cholerae isolated from regions endemic for cholera and strains from nonendemic regions. PMID:6874901

7. CONVEYOR DISCHARGE IN HOG HAIR PROCESSING AREA, NORTHWEST CORNER ...

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

7. CONVEYOR DISCHARGE IN HOG HAIR PROCESSING AREA, NORTHWEST CORNER OF LEVEL 2; HAIR WAS TRANSPORTED BY CONVEYOR FROM BUILDING 40, THEN WASHED, DRIED AND BALED IN BUILDING 148 - Rath Packing Company, Grease Interceptor Building, Sycamore Street between Elm & Eighteenth Streets, Waterloo, Black Hawk County, IA

9 CFR 311.30 - Livestock suffocated and hogs scalded alive.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Livestock suffocated and hogs scalded alive. 311.30 Section 311.30 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT... AND VOLUNTARY INSPECTION AND CERTIFICATION DISPOSAL OF DISEASED OR OTHERWISE ADULTERATED CARCASSES AND...

Dynamics of cholera epidemics from Benin to Mauritania.

PubMed

Moore, Sandra; Dongdem, Anthony Zunuo; Opare, David; Cottavoz, Paul; Fookes, Maria; Sadji, Adodo Yao; Dzotsi, Emmanuel; Dogbe, Michael; Jeddi, Fakhri; Bidjada, Bawimodom; Piarroux, Martine; Valentin, Ouyi Tante; Glèlè, Clément Kakaï; Rebaudet, Stanislas; Sow, Amy Gassama; Constantin de Magny, Guillaume; Koivogui, Lamine; Dunoyer, Jessica; Bellet, Francois; Garnotel, Eric; Thomson, Nicholas; Piarroux, Renaud

2018-04-01

The countries of West Africa are largely portrayed as cholera endemic, although the dynamics of outbreaks in this region of Africa remain largely unclear. To understand the dynamics of cholera in a major portion of West Africa, we analyzed cholera epidemics from 2009 to 2015 from Benin to Mauritania. We conducted a series of field visits as well as multilocus variable tandem repeat analysis and whole-genome sequencing analysis of V. cholerae isolates throughout the study region. During this period, Ghana accounted for 52% of the reported cases in the entire study region (coastal countries from Benin to Mauritania). From 2009 to 2015, we found that one major wave of cholera outbreaks spread from Accra in 2011 northwestward to Sierra Leone and Guinea in 2012. Molecular epidemiology analysis confirmed that the 2011 Ghanaian isolates were related to those that seeded the 2012 epidemics in Guinea and Sierra Leone. Interestingly, we found that many countries deemed "cholera endemic" actually suffered very few outbreaks, with multi-year lulls. This study provides the first cohesive vision of the dynamics of cholera epidemics in a major portion of West Africa. This epidemiological overview shows that from 2009 to 2015, at least 54% of reported cases concerned populations living in the three urban areas of Accra, Freetown, and Conakry. These findings may serve as a guide to better target cholera prevention and control efforts in the identified cholera hotspots in West Africa.

Dynamics of cholera epidemics from Benin to Mauritania

PubMed Central

Dongdem, Anthony Zunuo; Opare, David; Cottavoz, Paul; Fookes, Maria; Sadji, Adodo Yao; Dzotsi, Emmanuel; Dogbe, Michael; Jeddi, Fakhri; Bidjada, Bawimodom; Piarroux, Martine; Valentin, Ouyi Tante; Glèlè, Clément Kakaï; Rebaudet, Stanislas; Sow, Amy Gassama; Constantin de Magny, Guillaume; Koivogui, Lamine; Dunoyer, Jessica; Bellet, Francois; Garnotel, Eric; Thomson, Nicholas; Piarroux, Renaud

2018-01-01

Background The countries of West Africa are largely portrayed as cholera endemic, although the dynamics of outbreaks in this region of Africa remain largely unclear. Methodology/Principal findings To understand the dynamics of cholera in a major portion of West Africa, we analyzed cholera epidemics from 2009 to 2015 from Benin to Mauritania. We conducted a series of field visits as well as multilocus variable tandem repeat analysis and whole-genome sequencing analysis of V. cholerae isolates throughout the study region. During this period, Ghana accounted for 52% of the reported cases in the entire study region (coastal countries from Benin to Mauritania). From 2009 to 2015, we found that one major wave of cholera outbreaks spread from Accra in 2011 northwestward to Sierra Leone and Guinea in 2012. Molecular epidemiology analysis confirmed that the 2011 Ghanaian isolates were related to those that seeded the 2012 epidemics in Guinea and Sierra Leone. Interestingly, we found that many countries deemed “cholera endemic” actually suffered very few outbreaks, with multi-year lulls. Conclusions/Significance This study provides the first cohesive vision of the dynamics of cholera epidemics in a major portion of West Africa. This epidemiological overview shows that from 2009 to 2015, at least 54% of reported cases concerned populations living in the three urban areas of Accra, Freetown, and Conakry. These findings may serve as a guide to better target cholera prevention and control efforts in the identified cholera hotspots in West Africa. PMID:29630632

[The cholera epidemic in Latin America].

PubMed

Olsvik, O

1992-05-30

An outbreak of cholera started in Peru in January 1991 and spread through most Latin American countries within a year. This was the first known epidemic of cholera in America for more than a century. In 1991, 321,334 persons were reported to have cholera in Peru, 119,063 were hospitalized, and 2,906 died. Other countries like Ecuador, Colombia, Guatemala, Brazil, Mexico, Bolivia, Chile, El Salvador, Venezuela and Honduras were also affected, but these countries combined accounted for only 20% of the cases registered in Peru. In April 1992, all Latin American countries except Uruguay, Paraguay and French Guyana have reported cholera. The mortality rate for the epidemic in Latin America was only 1%, mainly owing to good oral rehydration treatment provided by Local health services and the Pan American Health Organization. The causative organism was Vibrio cholerae, serogroup O1, serotype Inaba (and Ogawa) of the El Tor biotype. Genetic characterization shows this strain to be unique, and the designation is reserved for the Latin American strain, distinguishing it from the other El Tor isolates from the 7th pandemic.

Resurgence of cholera in Hong Kong.

PubMed Central

Lee, S. H.; Lai, S. T.; Lai, J. Y.; Leung, N. K.

1996-01-01

Cholera is one of the three diseases subject to the International Health Regulations. After a period of over 30 years, the seventh pandemic of cholera, which started in South East Asia in 1961, still shows no sign of a decline. On the contrary, it has increased its severity and invaded many other countries in Africa and Latin America. In the last two years, there has been a recrudescence of the disease in South East Asia and Western Pacific Regions. The discovery of a new strain of Vibrio cholerae 0139 in these regions is causing concern in view of its potential to cause major epidemics and higher mortality. Hong Kong had two intensive outbreaks of cholera in the last two years. The cause of these outbreaks was not clear, but adverse environmental conditions and increasing pollution of coastal waters have been implicated. The spread of cholera knows no geographical boundaries. There is a need for intensified efforts among health authorities in the affected areas to prevent the international spread of the disease. PMID:8760949

Using infrared HOG-based pedestrian detection for outdoor autonomous searching UAV with embedded system

NASA Astrophysics Data System (ADS)

Shao, Yanhua; Mei, Yanying; Chu, Hongyu; Chang, Zhiyuan; He, Yuxuan; Zhan, Huayi

2018-04-01

Pedestrian detection (PD) is an important application domain in computer vision and pattern recognition. Unmanned Aerial Vehicles (UAVs) have become a major field of research in recent years. In this paper, an algorithm for a robust pedestrian detection method based on the combination of the infrared HOG (IR-HOG) feature and SVM is proposed for highly complex outdoor scenarios on the basis of airborne IR image sequences from UAV. The basic flow of our application operation is as follows. Firstly, the thermal infrared imager (TAU2-336), which was installed on our Outdoor Autonomous Searching (OAS) UAV, is used for taking pictures of the designated outdoor area. Secondly, image sequences collecting and processing were accomplished by using high-performance embedded system with Samsung ODROID-XU4 and Ubuntu as the core and operating system respectively, and IR-HOG features were extracted. Finally, the SVM is used to train the pedestrian classifier. Experiment show that, our method shows promising results under complex conditions including strong noise corruption, partial occlusion etc.

Avian cholera in Nebraska's Rainwater Basin

USGS Publications Warehouse

Windingstad, R.M.; Hurt, J.J.; Trout, A.K.; Cary, J.

1984-01-01

The first report of avian cholera in North America occurred in northwestern Texas in winter 1944 (Quortrup et al. 1946). In 1975, mortality from avian cholera occurred for the first time in waterfowl in the Rainwater Basin of Nebraska when an estimated 25,000 birds died (Zinkl et al. 1977). Avian cholera has continued to cause mortality in wild birds in specific areas of the Basin each spring since. Losses of waterfowl from avian cholera continue to be much greater in some of the wetlands in the western part of the Basin than in the east. Several wetlands in the west have consistently higher mortality and are most often the wetlands where initial mortality is noticed each spring (Figure 1). The establishment of this disease in Nebraska is of considerable concern because of the importance of the Rainwater Basin as a spring staging area for waterfowl migrating to their breeding grounds. The wetlands in this area are on a major migration route used by an estimated 5 to 9 million ducks and several hundred thousand geese. A large portion of the western mid-continental greater white-fronted goose (Anser albifrons) population stage in the Basin each spring. Occasionally, whooping cranes (Grus americana) use these wetlands during migration, and lesser sandhill cranes (Grus canadensis) staging on the nearby Platte River sometimes use wetlands where avian cholera occurs (Anonymous 1981). Our objectives were to determine whether certain water quality variables in the Rainwater Basin differed between areas of high and low avian cholera incidence. These results would then be used for laboratory studies involving the survivability of Pasteurella multocida, the causative bacterium of avian cholera. Those studies will be reported elsewhere.

Plasma and Mucosal Immunoglobulin M, Immunoglobulin A, and Immunoglobulin G Responses to the Vibrio cholerae O1 Protein Immunome in Adults With Cholera in Bangladesh.

PubMed

Charles, Richelle C; Nakajima, Rie; Liang, Li; Jasinskas, Al; Berger, Amanda; Leung, Daniel T; Kelly, Meagan; Xu, Peng; Kovác, Pavol; Giffen, Samantha R; Harbison, James D; Chowdhury, Fahima; Khan, Ashraful I; Calderwood, Stephen B; Bhuiyan, Taufiqur Rahman; Harris, Jason B; Felgner, Philip L; Qadri, Firdausi; Ryan, Edward T

2017-07-01

Cholera is a severe dehydrating illness of humans caused by toxigenic strains of Vibrio cholerae O1 or O139. Identification of immunogenic V. cholerae antigens could lead to a better understanding of protective immunity in human cholera. We probed microarrays containing 3652 V. cholerae antigens with plasma and antibody-in-lymphocyte supernatant (ALS, a surrogate marker of mucosal immune responses) from patients with severe cholera caused by V. cholerae O1 in Bangladesh and age-, sex-, and ABO-matched Bangladeshi controls. We validated a subset of identified antigens using enzyme-linked immunosorbent assay. Overall, we identified 608 immunoreactive V. cholerae antigens in our screening, 59 of which had higher immunoreactivity in convalescent compared with acute-stage or healthy control samples (34 in plasma, 39 in mucosal ALS; 13 in both sample sets). Identified antigens included cholera toxin B and A subunits, V. cholerae O-specific polysaccharide and lipopolysaccharide, toxin coregulated pilus A, sialidase, hemolysin A, flagellins (FlaB, FlaC, and FlaD), phosphoenolpyruvate-protein phosphotransferase, and diaminobutyrate-2-oxoglutarate aminotransferase. This study is the first antibody profiling of the mucosal and systemic antibody responses to the nearly complete V. cholerae O1 protein immunome; it has identified antigens that may aid in the development of an improved cholera vaccine. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Genome assortment, not serogroup, defines Vibrio cholerae pandemic strains

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brettin, Thomas S; Bruce, David C; Challacombe, Jean F

2009-01-01

Vibrio cholerae, the causative agent of cholera, is a bacterium autochthonous to the aquatic environment, and a serious public health threat. V. cholerae serogroup O1 is responsible for the previous two cholera pandemics, in which classical and El Tor biotypes were dominant in the 6th and the current 7th pandemics, respectively. Cholera researchers continually face newly emerging and re-emerging pathogenic clones carrying combinations of new serogroups as well as of phenotypic and genotypic properties. These genotype and phenotype changes have hampered control of the disease. Here we compare the complete genome sequences of 23 strains of V. cholerae isolated frommore » a variety of sources and geographical locations over the past 98 years in an effort to elucidate the evolutionary mechanisms governing genetic diversity and genesis of new pathogenic clones. The genome-based phylogeny revealed 12 distinct V. cholerae phyletic lineages, of which one, designated the V. cholerae core genome (CG), comprises both O1 classical and EI Tor biotypes. All 7th pandemic clones share nearly identical gene content, i.e., the same genome backbone. The transition from 6th to 7th pandemic strains is defined here as a 'shift' between pathogenic clones belonging to the same O1 serogroup, but from significantly different phyletic lineages within the CG clade. In contrast, transition among clones during the present 7th pandemic period can be characterized as a 'drift' between clones, differentiated mainly by varying composition of laterally transferred genomic islands, resulting in emergence of variants, exemplified by V.cholerae serogroup O139 and V.cholerae O1 El Tor hybrid clones that produce cholera toxin of classical biotype. Based on the comprehensive comparative genomics presented in this study it is concluded that V. cholerae undergoes extensive genetic recombination via lateral gene transfer, and, therefore, genome assortment, not serogroup, should be used to define pathogenic

Vibrio cholerae genomic diversity within and between patients

PubMed Central

Levade, Inès; Terrat, Yves; Leducq, Jean-Baptiste; Weil, Ana A.; Mayo-Smith, Leslie M.; Chowdhury, Fahima; Khan, Ashraful I.; Boncy, Jacques; Buteau, Josiane; Ivers, Louise C.; Ryan, Edward T.; Charles, Richelle C.; Calderwood, Stephen B.; Qadri, Firdausi; Harris, Jason B.; LaRocque, Regina C.

2017-01-01

Cholera is a severe, water-borne diarrhoeal disease caused by toxin-producing strains of the bacterium Vibrio cholerae. Comparative genomics has revealed ‘waves’ of cholera transmission and evolution, in which clones are successively replaced over decades and centuries. However, the extent of V. cholerae genetic diversity within an epidemic or even within an individual patient is poorly understood. Here, we characterized V. cholerae genomic diversity at a micro-epidemiological level within and between individual patients from Bangladesh and Haiti. To capture within-patient diversity, we isolated multiple (8 to 20) V. cholerae colonies from each of eight patients, sequenced their genomes and identified point mutations and gene gain/loss events. We found limited but detectable diversity at the level of point mutations within hosts (zero to three single nucleotide variants within each patient), and comparatively higher gene content variation within hosts (at least one gain/loss event per patient, and up to 103 events in one patient). Much of the gene content variation appeared to be due to gain and loss of phage and plasmids within the V. cholerae population, with occasional exchanges between V. cholerae and other members of the gut microbiota. We also show that certain intra-host variants have phenotypic consequences. For example, the acquisition of a Bacteroides plasmid and non-synonymous mutations in a sensor histidine kinase gene both reduced biofilm formation, an important trait for environmental survival. Together, our results show that V. cholerae is measurably evolving within patients, with possible implications for disease outcomes and transmission dynamics. PMID:29306353

Household Transmission of Vibrio cholerae in Bangladesh

PubMed Central

Sugimoto, Jonathan D.; Koepke, Amanda A.; Kenah, Eben E.; Halloran, M. Elizabeth; Chowdhury, Fahima; Khan, Ashraful I.; LaRocque, Regina C.; Yang, Yang; Ryan, Edward T.; Qadri, Firdausi; Calderwood, Stephen B.; Harris, Jason B.; Longini, Ira M.

2014-01-01

Background Vibrio cholerae infections cluster in households. This study's objective was to quantify the relative contribution of direct, within-household exposure (for example, via contamination of household food, water, or surfaces) to endemic cholera transmission. Quantifying the relative contribution of direct exposure is important for planning effective prevention and control measures. Methodology/Principal Findings Symptom histories and multiple blood and fecal specimens were prospectively collected from household members of hospital-ascertained cholera cases in Bangladesh from 2001–2006. We estimated the probabilities of cholera transmission through 1) direct exposure within the household and 2) contact with community-based sources of infection. The natural history of cholera infection and covariate effects on transmission were considered. Significant direct transmission (p-value<0.0001) occurred among 1414 members of 364 households. Fecal shedding of O1 El Tor Ogawa was associated with a 4.9% (95% confidence interval: 0.9%–22.8%) risk of infection among household contacts through direct exposure during an 11-day infectious period (mean length). The estimated 11-day risk of O1 El Tor Ogawa infection through exposure to community-based sources was 2.5% (0.8%–8.0%). The corresponding estimated risks for O1 El Tor Inaba and O139 infection were 3.7% (0.7%–16.6%) and 8.2% (2.1%–27.1%) through direct exposure, and 3.4% (1.7%–6.7%) and 2.0% (0.5%–7.3%) through community-based exposure. Children under 5 years-old were at elevated risk of infection. Limitations of the study may have led to an underestimation of the true risk of cholera infection. For instance, available covariate data may have incompletely characterized levels of pre-existing immunity to cholera infection. Transmission via direct exposure occurring outside of the household was not considered. Conclusions Direct exposure contributes substantially to endemic transmission of symptomatic

Cholera Outbreaks in Nigeria Are Associated with Multidrug Resistant Atypical El Tor and Non-O1/Non-O139 Vibrio cholerae

PubMed Central

Marin, Michel A.; Thompson, Cristiane C.; Freitas, Fernanda S.; Fonseca, Erica L.; Aboderin, A. Oladipo; Zailani, Sambo B.; Quartey, Naa Kwarley E.; Okeke, Iruka N.; Vicente, Ana Carolina P.

2013-01-01

Background The current millennium has seen a steep rise in the number, size and case-fatalities of cholera outbreaks in many African countries. Over 40,000 cases of cholera were reported from Nigeria in 2010. Variants of Vibrio cholerae O1 El Tor biotype have emerged but very little is known about strains causing cholera outbreaks in West Africa, which is crucial for the implementation of interventions to control epidemic cholera. Methodology/Principal Findings V. cholerae isolates from outbreaks of acute watery diarrhea in Nigeria from December, 2009 to October, 2010 were identified by standard culture methods. Fifteen O1 and five non-O1/non-O139 strains were analyzed; PCR and sequencing targeted regions associated with virulence, resistance and biotype were performed. We also studied genetic interrelatedness among the strains by multilocus sequence analysis and pulsed-field gel electrophoresis. The antibiotic susceptibility was tested by the disk diffusion method and E-test. We found that multidrug resistant atypical El Tor strains, with reduced susceptibility to ciprofloxacin and chloramphenicol, characterized by the presence of the SXT element, and gyrA Ser83Ile/parC Ser85Leu alleles as well CTX phage and TCP cluster characterized by rstR ElTor, ctxB-7 and tcpA CIRS alleles, respectively, were largely responsible for cholera outbreaks in 2009 and 2010. We also identified and characterized a V. cholerae non-O1/non-O139 lineage from cholera-like diarrhea cases in Nigeria. Conclusions/Significance The recent Nigeria outbreaks have been determined by multidrug resistant atypical El Tor and non-O1/non-O139 V. cholerae strains, and it seems that the typical El Tor, from the beginning of seventh cholera pandemic, is no longer epidemic/endemic in this country. This scenario is similar to the East Africa, Asia and Caribbean countries. The detection of a highly virulent, antimicrobial resistant lineage in Nigeria is worrisome and points to a need for vaccine

Jamestown IslandHog IslandCaptain John Smith Chesapeake National Historic Trail District, ...

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

Jamestown Island-Hog Island-Captain John Smith Chesapeake National Historic Trail District, James River plus the land 0.5 miles inland, roughly from Swann's Point to Pagan River, Jamestown, James City County, VA

Metabolic Respiration Induces AMPK- and Ire1p-Dependent Activation of the p38-Type HOG MAPK Pathway

PubMed Central

Adhikari, Hema; Cullen, Paul J.

2014-01-01

Evolutionarily conserved mitogen activated protein kinase (MAPK) pathways regulate the response to stress as well as cell differentiation. In Saccharomyces cerevisiae, growth in non-preferred carbon sources (like galactose) induces differentiation to the filamentous cell type through an extracellular-signal regulated kinase (ERK)-type MAPK pathway. The filamentous growth MAPK pathway shares components with a p38-type High Osmolarity Glycerol response (HOG) pathway, which regulates the response to changes in osmolarity. To determine the extent of functional overlap between the MAPK pathways, comparative RNA sequencing was performed, which uncovered an unexpected role for the HOG pathway in regulating the response to growth in galactose. The HOG pathway was induced during growth in galactose, which required the nutrient regulatory AMP-dependent protein kinase (AMPK) Snf1p, an intact respiratory chain, and a functional tricarboxylic acid (TCA) cycle. The unfolded protein response (UPR) kinase Ire1p was also required for HOG pathway activation in this context. Thus, the filamentous growth and HOG pathways are both active during growth in galactose. The two pathways redundantly promoted growth in galactose, but paradoxically, they also inhibited each other's activities. Such cross-modulation was critical to optimize the differentiation response. The human fungal pathogen Candida albicans showed a similar regulatory circuit. Thus, an evolutionarily conserved regulatory axis links metabolic respiration and AMPK to Ire1p, which regulates a differentiation response involving the modulated activity of ERK and p38 MAPK pathways. PMID:25356552

Avian cholera

USGS Publications Warehouse

Friend, Milton

1999-01-01

Avian cholera is a contagious disease resulting from infection by the bacterium Pasteurella multocida. Several subspecies of bacteria have been proposed for P. multocida, and at least 16 different P. multocida serotypes or characteristics of antigens in bacterial cells that differentiate bacterial variants from each other have been recognized. The serotypes are further differentiated by other methods, including DNA fingerprinting. These evaluations are useful for studying the ecology of avian cholera (Fig. 7.1), because different serotypes are generally found in poultry and free-ranging migratory birds. These evaluations also show that different P. multocida serotypes are found in wild birds in the eastern United States than those that are found in the birds in the rest of the Nation (Fig. 7.2).

[Survival of Vibrio cholerae 01 in freshwater surface and endemic cholera: a geological hypothesis].

PubMed

Borroto, R J

1998-12-01

The danger that cholera is becoming endemic in Latin America makes it imperative to know the geographic location of aquatic environments where ecological conditions favor long-term survival of the toxigenic Vibrio cholerae O1 El Tor biotype, and such aquatic environments should be sampled to determine if they harbor this microorganism. For efficient and effective sampling, it would be useful to know what kinds of waters are ecologically suitable for the survival of this pathogen during periods between epidemics, and where these bodies of water are located. This paper presents the hypothesis that toxigenic V. cholerae O1's ability to survive in surface freshwaters tends to be inversely related to the altitude above sea level of these freshwaters.

The molecular epidemiology of cholera in Latin America.

PubMed

Wachsmuth, I K; Evins, G M; Fields, P I; Olsvik, O; Popovic, T; Bopp, C A; Wells, J G; Carrillo, C; Blake, P A

1993-03-01

To explain the sudden appearance and rapid spread of cholera in Latin America in January 1991, molecular techniques were used to define Vibrio cholerae O1 isolates from around the world. Restriction fragment length polymorphisms of rRNA and ctxA genes, DNA sequence of cholera toxin B subunit gene ctxB, and multilocus enzyme electrophoresis data were used to characterize 197 isolates. Worldwide, there are at least four distinct toxigenic El Tor V. cholerae O1 clones: the seventh pandemic (Eastern Hemisphere), US Gulf Coast, Australian, and Latin American. Nontoxigenic V. cholerae O1 previously isolated in Brazil, Mexico, and Peru are unlike current toxigenic isolates. The Latin American clone probably represents an extension of the seventh pandemic into the Western Hemisphere, while the US Gulf Coast clone most likely evolved separately. These data will be useful in monitoring the spread of cholera, determining the origin of outbreaks in both hemispheres, and implicating specific vehicles of transmission.

Herald waves of cholera in nineteenth century London

PubMed Central

Tien, Joseph H.; Poinar, Hendrik N.; Fisman, David N.; Earn, David J. D.

2011-01-01

Deaths from cholera in London, UK, were recorded weekly from 1824 to 1901. Three features of the time series stand out: (i) cholera deaths were strongly seasonal, with peak mortality almost always in the summer, (ii) the only non-summer outbreaks occurred in the spring of 1832, the autumn of 1848 and the winter of 1853, and (iii) extraordinarily severe summer outbreaks occurred in 1832, 1849, 1854 and 1866 (the four ‘great’ cholera years). The non-summer outbreaks of 1832, 1848 and 1853 appear to have been herald waves of newly invading cholera strains. In addition, a simple mathematical model confirms that a non-summer introduction of a new cholera strain can result in an initial herald wave, followed by a severe outbreak the following summer. Through the analysis of the genomes of nineteenth-century specimens, it may be possible to identify the strains that caused these herald waves and the well-known cholera epidemics that followed. PMID:21123253

Herald waves of cholera in nineteenth century London.

PubMed

Tien, Joseph H; Poinar, Hendrik N; Fisman, David N; Earn, David J D

2011-05-06

Deaths from cholera in London, UK, were recorded weekly from 1824 to 1901. Three features of the time series stand out: (i) cholera deaths were strongly seasonal, with peak mortality almost always in the summer, (ii) the only non-summer outbreaks occurred in the spring of 1832, the autumn of 1848 and the winter of 1853, and (iii) extraordinarily severe summer outbreaks occurred in 1832, 1849, 1854 and 1866 (the four 'great' cholera years). The non-summer outbreaks of 1832, 1848 and 1853 appear to have been herald waves of newly invading cholera strains. In addition, a simple mathematical model confirms that a non-summer introduction of a new cholera strain can result in an initial herald wave, followed by a severe outbreak the following summer. Through the analysis of the genomes of nineteenth-century specimens, it may be possible to identify the strains that caused these herald waves and the well-known cholera epidemics that followed.

Unique Clones of Vibrio cholerae O1 El Tor with Haitian Type ctxB Allele Implicated in the Recent Cholera Epidemics from Nigeria, Africa.

PubMed

Adewale, Akinsinde Kehinde; Pazhani, Gururaja Perumal; Abiodun, Iwalokun Bamidele; Afolabi, Oluwadun; Kolawole, Olukoya Daniel; Mukhopadhyay, Asish K; Ramamurthy, Thanadarayan

2016-01-01

The antimicrobial susceptibility patterns and genetic characteristics of Vibrio cholerae O1, which is responsible for several cholera epidemics in Nigeria, are not reported in detail since 2007. In this study, we screened V. cholerae O1 El Tor biotype isolates from cholera cases and water samples from different states to investigate their phenotypic and genetic attributes with special reference to their clonality. All the V. cholerae O1 biotype El Tor isolates isolated during 2007-2013 were susceptible to fluoroquinolones and tetracycline, the drugs currently used in the treatment of cholera cases in Nigeria. Emergence of CT genotype 7 (Haitian type of ctxB allele) was predominantly seen among Ogawa serotype and the CT genotype 1 (classical ctxB allele) was mostly found in Inaba serotype. Overall, V. cholerae O1 from clinical and water samples were found to be closely related as determined by the pulsed-field gel electrophoresis. V. cholerae isolates from Abia, Kano and Bauchi were found to be genetically distinct from the other states of Nigeria. Fecal contamination of the water sources may be the possible source of the cholera infection. Combined prevalence of Haitian and classical ctxB alleles were detected in Ogawa and Inaba serotypes, respectively. This study further demonstrated that V. cholerae O1 with the ctxB has been emerged similar to the isolates reported in Haiti. Our findings suggest that the use of fluoroquinolones or tetracycline/doxycycline may help in the effective management of acute cholera in the affected Nigerian states. In addition, strengthening the existing surveillance in the hospitals of all the states and supply of clean drinking water may control cholera outbreaks in the future.

[Seroepidemiology of cholera in Mexico].

PubMed

González-Bonilla, C; Valle-Valdez, J G; Núñez-León, A; Moguel-Pech, L; Villanueva-Zamudio, A

1994-01-01

Antibodies against Vibrio cholerae were determined in 2352 serum samples obtained from patients with clinical diagnosis of cholera. Samples from their contacts and from healthy people living in the same communities were also analyzed. Vibriocidal antibodies with titers 1:160 or higher were observed in 25% of the samples. An increase of vibriocidal and antitoxin antibody titers were observed in 56 to 60% of the patients in which paired samples were available, one obtained in the acute phase of the disease and the other in the convalescence, confirming the diagnosis of cholera. Differences in the antibody titers were noticed when comparing the serotype according to the geographic area and the season of the year.

Cholera in pregnancy: outcomes from a specialized cholera treatment unit for pregnant women in Léogâne, Haiti.

PubMed

Ciglenecki, Iza; Bichet, Mathieu; Tena, Javier; Mondesir, Erneau; Bastard, Mathieu; Tran, Nguyen-Toan; Antierens, Annick; Staderini, Nelly

2013-01-01

The association between cholera in pregnancy and negative fetal outcome has been described since the 19(th) century. However, there is limited published literature on the subject. We describe pregnancy outcomes from a specialized multidisciplinary hospital unit at the onset of a large cholera outbreak in Haiti in 2010 and 2011. Pregnant women with cholera were hospitalized in a specialized unit within the MSF hospital compound in Léogâne and treated using standard cholera treatment guidelines but with earlier, more intense fluid replacement. All women had intravenous access established at admission regardless of their hydration status, and all received antibiotic treatment. Data were collected on patient demographics, pregnancy and cholera status, and pregnancy outcome. In this analysis we calculated risk ratios for fetal death and performed logistic regression analysis to control for confounding factors. 263 pregnant women with cholera were hospitalized between December 2010 and July 2011. None died during hospitalization, 226 (86%) were discharged with a preserved pregnancy and 16 (6%) had live fullterm singleton births, of whom 2 died within the first 5 days postpartum. The remaining 21 pregnancies (8%) resulted in intrauterine fetal death. The risk of fetal death was associated with factors reflecting severity of the cholera episode: after adjusting for confounding factors, the strongest risk factor for fetal death was severe maternal dehydration (adjusted risk ratio for severe vs. mild dehydration was 9.4, 95% CI 2.5-35.3, p = 0.005), followed by severe vomiting (adjusted risk ratio 5.1, 95% 1.1-23.8, p = 0.041). This is the largest cohort of pregnant women with cholera described to date. The main risk factor identified for fetal death was severity of dehydration. Our experience suggests that establishing specialized multidisciplinary units which facilitate close follow-up of both pregnancy and dehydration status due to cholera could be beneficial

Time Series Analysis of Cholera in Matlab, Bangladesh, during 1988-2001

PubMed Central

Kim, Deok Ryun; Yunus, Mohammad; Emch, Michael

2013-01-01

The study examined the impact of in-situ climatic and marine environmental variability on cholera incidence in an endemic area of Bangladesh and developed a forecasting model for understanding the magnitude of incidence. Diarrhoea surveillance data collected between 1988 and 2001were obtained from a field research site in Matlab, Bangladesh. Cholera cases were defined as Vibrio cholerae O1 isolated from faecal specimens of patients who sought care at treatment centres serving the Matlab population. Cholera incidence for 168 months was correlated with remotely-sensed sea-surface temperature (SST) and in-situ environmental data, including rainfall and ambient temperature. A seasonal autoregressive integrated moving average (SARIMA) model was used for determining the impact of climatic and environmental variability on cholera incidence and evaluating the ability of the model to forecast the magnitude of cholera. There were 4,157 cholera cases during the study period, with an average of 1.4 cases per 1,000 people. Since monthly cholera cases varied significantly by month, it was necessary to stabilize the variance of cholera incidence by computing the natural logarithm to conduct the analysis. The SARIMA model shows temporal clustering of cholera at one- and 12-month lags. There was a 6% increase in cholera incidence with a minimum temperature increase of one degree celsius in the current month. For increase of SST by one degree celsius, there was a 25% increase in the cholera incidence at currrent month and 18% increase in the cholera incidence at two months. Rainfall did not influenc to cause variation in cholera incidence during the study period. The model forecast the fluctuation of cholera incidence in Matlab reasonably well (Root mean square error, RMSE: 0.108). Thus, the ambient and sea-surface temperature-based model could be used in forecasting cholera outbreaks in Matlab. PMID:23617200

Time series analysis of cholera in Matlab, Bangladesh, during 1988-2001.

PubMed

Ali, Mohammad; Kim, Deok Ryun; Yunus, Mohammad; Emch, Michael

2013-03-01

The study examined the impact of in-situ climatic and marine environmental variability on cholera incidence in an endemic area of Bangladesh and developed a forecasting model for understanding the magnitude of incidence. Diarrhoea surveillance data collected between 1988 and 2001 were obtained from a field research site in Matlab, Bangladesh. Cholera cases were defined as Vibrio cholerae O1 isolated from faecal specimens of patients who sought care at treatment centres serving the Matlab population. Cholera incidence for 168 months was correlated with remotely-sensed sea-surface temperature (SST) and in-situ environmental data, including rainfall and ambient temperature. A seasonal autoregressive integrated moving average (SARIMA) model was used for determining the impact of climatic and environmental variability on cholera incidence and evaluating the ability of the model to forecast the magnitude of cholera. There were 4,157 cholera cases during the study period, with an average of 1.4 cases per 1,000 people. Since monthly cholera cases varied significantly by month, it was necessary to stabilize the variance of cholera incidence by computing the natural logarithm to conduct the analysis. The SARIMA model shows temporal clustering of cholera at one- and 12-month lags. There was a 6% increase in cholera incidence with a minimum temperature increase of one degree celsius in the current month. For increase of SST by one degree celsius, there was a 25% increase in the cholera incidence at currrent month and 18% increase in the cholera incidence at two months. Rainfall did not influenc to cause variation in cholera incidence during the study period. The model forecast the fluctuation of cholera incidence in Matlab reasonably well (Root mean square error, RMSE: 0.108). Thus, the ambient and sea-surface temperature-based model could be used in forecasting cholera outbreaks in Matlab.

Geographical patterns of cholera in Mexico, 1991-1996.

PubMed

Borroto, R J; Martinez-Piedra, R

2000-08-01

The seventh cholera pandemic has been ongoing in Mexico since 1991 and threatens to become endemic. This paper aims to determine the geographical pattern of cholera in Mexico to define areas at high risk of endemic cholera. Ecologic research was conducted based upon the cartography of disease incidence. The 32 Mexican states were grouped into five strata according to the value of the 1991-1996 cumulative incidence rate of cholera. Rate ratios were computed for strata of states classified by geographical situation, urbanization, and poverty level. Cholera incidence was 2.47 times higher in coastal states than in the interior (95% CI : 2.42-2.52). The disease was negatively associated with urbanization. Incidence in the least urbanized stratum was four times as high as in the most urban stratum (95% CI : 3.9-4.12). The poorest stratum showed the most remarkable incidence, i.e. 5.9 times higher than the rate in the least poor stratum (95% CI : 5.73-6.04). This ecologic research suggests that high poverty level, low urbanization, and southern location are the most important predictors of endemic cholera in Mexican states. It is hypothesized that the natural environment of the coastal plains in southern states may also play a significant role in cholera incidence. Poor communities residing in the southern, predominantly rural, coastal states should be prioritized when it comes to investing in safe water supply facilities, adequate excreta disposal systems and cholera surveillance.

Vibrio cholerae: lessons for mucosal vaccine design

PubMed Central

Bishop, Anne L; Camilli, Andrew

2011-01-01

The ability of Vibrio cholerae to persist in bodies of water will continue to confound our ability to eradicate cholera through improvements to infrastructure, and thus cholera vaccines are needed. We aim for an inexpensive vaccine that can provide long-lasting protection from all epidemic cholera infections, currently caused by O1 or O139 serogroups. Recent insights into correlates of protection, epidemiology and pathogenesis may help us design improved vaccines. This notwithstanding, we have come to appreciate that even marginally protective vaccines, such as oral whole-cell killed vaccines, if widely distributed, can provide significant protection, owing to herd immunity. Further efforts are still required to provide more effective protection of young children. PMID:21162623

Effect of Dietary Minerals on Virulence Attributes of Vibrio cholerae

PubMed Central

Bhattaram, Varunkumar; Upadhyay, Abhinav; Yin, Hsin-Bai; Mooyottu, Shankumar; Venkitanarayanan, Kumar

2017-01-01

Vibrio cholerae is a water-borne pathogen responsible for causing a toxin-mediated profuse diarrhea in humans, leading to severe dehydration and death in unattended patients. With increasing reports of antibiotic resistance in V. cholerae, there is a need for alternate interventional strategies for controlling cholera. A potential new strategy for treating infectious diseases involves targeting bacterial virulence rather than growth, where a pathogen’s specific mechanisms critical for causing infection in hosts are inhibited. Since bacterial motility, intestinal colonization and cholera toxin are critical components in V. cholerae pathogenesis, attenuating these virulence factors could potentially control cholera in humans. In this study, the efficacy of sub-inhibitory concentration (SIC, highest concentration not inhibiting bacterial growth) of essential minerals, zinc (Zn), selenium (Se), and manganese (Mn) in reducing V. cholerae motility and adhesion to intestinal epithelial cells (Caco-2), cholera toxin production, and toxin binding to the ganglioside receptor (GM1) was investigated. Additionally, V. cholerae attachment and toxin production in an ex vivo mouse intestine model was determined. Further, the effect of Zn, Se and Mn on V. cholerae virulence genes, ctxAB (toxin production), fliA (motility), tcpA (intestinal colonization), and toxR (master regulon) was determined using real-time quantitative PCR. All three minerals significantly reduced V. cholerae motility, adhesion to Caco-2 cells, and cholera toxin production in vitro, and decreased adhesion and toxin production in mouse intestine ex vivo (P < 0.05). In addition, Zn, Se, and Mn down-regulated the transcription of virulence genes, ctxAB, fliA, and toxR. Results suggest that Zn, Se, and Mn could be potentially used to reduce V. cholerae virulence. However, in vivo studies in an animal model are necessary to validate these results. PMID:28579983

Virulence factors, pathogenesis and vaccine protection in cholera and ETEC diarrhea.

PubMed

Sánchez, Joaquín; Holmgren, Jan

2005-08-01

Recent work has provided new insights into the pathogenesis of the potentially life-threatening diarrheas caused by Vibrio cholerae and enterotoxigenic Escherichia coli (ETEC): a new mechanism (post-translational degradation), which is involved in the control of cholera toxin expression, has been discovered. Recent evidence also suggests that vibrios upregulate cholera toxin expression in response to intestinal fluid components, and enterotoxin-carrying bacterial outer membrane vesicles might have a function in ETEC pathogenesis. An important role of the environment is supported by the correlation between cholera incidence and elevated sea surface temperature, which supports the notion that the zooplankton is a V. cholerae reservoir. Additionally, environmental lytic cholera phages could influence cholera seasonality by 'terminating' the seasonal epidemic. Finally, the strong herd immunity elicited by an oral cholera vaccine indicates that cholera vaccination could have a significant public health impact.

An evolutionarily stable strategy and the critical point of hog futures trading entities based on replicator dynamic theory: 2006–2015 data for China’s 22 provinces

PubMed Central

Pang, Jinbo; Deng, Lingfei

2017-01-01

Although frequent fluctuations in domestic hog prices seriously affect the stability and robustness of the hog supply chain, hog futures (an effective hedging instrument) have not been listed in China. To better understand hog futures market hedging, it is important to study the steady state of intersubjective bidding. This paper uses evolutionary game theory to construct a game model between hedgers and speculators in the hog futures market, and replicator dynamic equations are then used to obtain the steady state between the two trading entities. The results show that the steady state is one in which hedgers adopt a “buy” strategy and speculators adopt a “do not speculate” strategy, but this type of extreme steady state is not easily realized. Thus, to explore the rational proportion of hedgers and speculators in the evolutionary stabilization strategy, bidding processes were simulated using weekly average hog prices from 2006 to 2015, such that the conditions under which hedgers and speculators achieve a steady state could be analyzed. This task was performed to achieve the stability critical point, and we show that only when the value of λ is satisfied and the conditions of hog futures price changes and futures price are satisfied can hedgers and speculators achieve a rational proportion and a stable hog futures market. This market can thus provide a valuable reference for the development of the Chinese hog futures market and the formulation and guidance of relevant departmental policies. PMID:28241024

Spreading of Cholera through Surface Water

NASA Astrophysics Data System (ADS)

Bertuzzo, E.; Casagrandi, R.; Gatto, M.; Rodriguez-Iturbe, I.; Rinaldo, A.

2009-12-01

Cholera epidemics are still a major public health concern to date in many areas of the world. In order to understand and forecast cholera outbreaks, one of the most important factors is the role played by the environmental matrix in which the disease spreads. We study how river networks, acting as environmental corridors for pathogens, affect the spreading of cholera epidemics. The environmental matrix in which the disease spreads is constituted by different human communities and their hydrologic interconnections. Each community is characterized by its spatial position, population size, water resources availability and hygiene conditions. By implementing a spatially explicit cholera model we seek the effects on epidemic dynamics of: i) the topology and metrics of the pathogens pathways that connect different communities; ii) the spatial distribution of the population size; and iii) the spatial distributions and quality of surface water resources and public health conditions, and how they vary with population size. The model has been applied to study the space-time evolution of a well documented cholera epidemic occurred in the KwaZulu-Natal province of South Africa. The epidemic lasted for two years and involved about 140,000 confirmed cholera cases. The model does well in reproducing the distribution of the cholera cases during the two outbreaks as well as their spatial spreading. We further extend the model by deriving the speed of propagation of traveling fronts in the case of uniformly distributed systems for different topologies: one and two dimensional lattices and river networks. The derivation of the spreading celerity proves instrumental in establishing the overall conditions for the relevance of spatially explicit models. The conditions are sought by comparison between spreading and disease timescales. Consider a cholera epidemic that starts from a point and spreads throughout a finite size system, it is possible to identify two different timescales: i

Unique Clones of Vibrio cholerae O1 El Tor with Haitian Type ctxB Allele Implicated in the Recent Cholera Epidemics from Nigeria, Africa

PubMed Central

Pazhani, Gururaja Perumal; Abiodun, Iwalokun Bamidele; Afolabi, Oluwadun; Kolawole, Olukoya Daniel; Mukhopadhyay, Asish K.; Ramamurthy, Thanadarayan

2016-01-01

Background and Objectives The antimicrobial susceptibility patterns and genetic characteristics of Vibrio cholerae O1, which is responsible for several cholera epidemics in Nigeria, are not reported in detail since 2007. In this study, we screened V. cholerae O1 El Tor biotype isolates from cholera cases and water samples from different states to investigate their phenotypic and genetic attributes with special reference to their clonality. Results All the V. cholerae O1 biotype El Tor isolates isolated during 2007–2013 were susceptible to fluoroquinolones and tetracycline, the drugs currently used in the treatment of cholera cases in Nigeria. Emergence of CT genotype 7 (Haitian type of ctxB allele) was predominantly seen among Ogawa serotype and the CT genotype 1 (classical ctxB allele) was mostly found in Inaba serotype. Overall, V. cholerae O1 from clinical and water samples were found to be closely related as determined by the pulsed-field gel electrophoresis. V. cholerae isolates from Abia, Kano and Bauchi were found to be genetically distinct from the other states of Nigeria. Conclusion Fecal contamination of the water sources may be the possible source of the cholera infection. Combined prevalence of Haitian and classical ctxB alleles were detected in Ogawa and Inaba serotypes, respectively. This study further demonstrated that V. cholerae O1 with the ctxB has been emerged similar to the isolates reported in Haiti. Our findings suggest that the use of fluoroquinolones or tetracycline/doxycycline may help in the effective management of acute cholera in the affected Nigerian states. In addition, strengthening the existing surveillance in the hospitals of all the states and supply of clean drinking water may control cholera outbreaks in the future. PMID:27479360

The health economics of cholera: A systematic review.

PubMed

Hsiao, Amber; Hall, Angela H; Mogasale, Vittal; Quentin, Wilm

2018-06-12

Vibrio cholera is a major contributor of diarrheal illness that causes significant morbidity and mortality globally. While there is literature on the health economics of diarrheal illnesses more generally, few studies have quantified the cost-of-illness and cost-effectiveness of cholera-specific prevention and control interventions. The present systematic review provides a comprehensive overview of the literature specific to cholera as it pertains to key health economic measures. A systematic review was performed with no date restrictions up through February 2017 in PubMed, Econlit, Embase, Web of Science, and Cochrane Review to identify relevant health economics of cholera literature. After removing duplicates, a total of 1993 studies were screened and coded independently by two reviewers, resulting in 22 relevant studies. Data on population, methods, and results (cost-of-illness and cost-effectiveness of vaccination) were compared by country/region. All costs were adjusted to 2017 USD for comparability. Costs per cholera case were found to be rather low: <$100 per case in most settings, even when costs incurred by patients/families and lost productivity are considered. When wider socioeconomic costs are included, estimated costs are >$1000/case. There is adequate evidence to support the economic value of vaccination for the prevention and control of cholera when vaccination is targeted at high-incidence populations and/or areas with high case fatality rates due to cholera. When herd immunity is considered, vaccination also becomes a cost-effective option for the general population and is comparable in cost-effectiveness to other routine immunizations. Cholera vaccination is a viable short-to-medium term option, especially as the upfront costs of building water, sanitation, and hygiene (WASH) infrastructure are considerably higher for countries that face a significant burden of cholera. While WASH may be the more cost-effective solution in the long-term when

Knowledge of, attitudes toward, and preventive practices relating to cholera and oral cholera vaccine among urban high-risk groups: findings of a cross-sectional study in Dhaka, Bangladesh

PubMed Central

2013-01-01

Background In endemic countries such as Bangladesh, consequences of cholera place an enormous financial and social burden on patients and their families. Cholera vaccines not only provide health benefits to susceptible populations but also have effects on the earning capabilities and financial stability of the family. Community-based research and evaluations are necessary to understand perceptions about and practices of the community relating to cholera and oral cholera vaccines. This may help identify the ways in which such vaccines may be successfully introduced, and other preventive measures can be implemented. The present study assessed the knowledge of, attitudes toward, and preventive practices relating to cholera and oral cholera vaccine among an urban population residing in a high cholera-prone setting in Dhaka, Bangladesh. Methods This cross-sectional study was conducted in an area of high cholera prevalence in 15 randomly-selected clusters in Mirpur, Dhaka city. A study team collected data through a survey and in-depth interviews during December 2010–February 2011. Results Of 2,830 families included in the final analysis, 23% could recognize cholera as acute watery diarrhea and 16% had ever heard of oral cholera vaccine. About 54% of the respondents had poor knowledge about cholera-related issues while 97% had a positive attitude toward cholera and oral cholera vaccine. One-third showed poor practice relating to the prevention of cholera. The findings showed a significant (p < 0.05) association between the respondents’ knowledge and sex, education, occupation, monthly overall household expenditure, attitudes and practice. In the adjusted model, male sex, having a lower monthly overall household expenditure, and having a less positive attitude toward cholera were the significant predictors to having poor knowledge. Conclusions The findings suggest the strengthening of health education activities to improve knowledge on cholera, its prevention and

Cholera risk factors, Papua New Guinea, 2010.

PubMed

Rosewell, Alexander; Addy, Benita; Komnapi, Lucas; Makanda, Freda; Ropa, Berry; Posanai, Enoch; Dutta, Samir; Mola, Glen; Man, W Y Nicola; Zwi, Anthony; MacIntyre, C Raina

2012-11-05

Cholera is newly emergent in Papua New Guinea but may soon become endemic. Identifying the risk factors for cholera provides evidence for targeted prevention and control measures. We conducted a hospital-based case-control study to identify cholera risk factors. Using stool culture as the standard, we evaluated a cholera point of care test in the field. 176 participants were recruited: 54 cases and 122 controls. Independent risk factors for cholera were: being over 20 years of age (aOR 2.5; 95%CI 1.1, 5.4), defecating in the open air (or river) (aOR 4.5; 95% CI 1.4, 14.4) and knowing someone who travelled to a cholera affected area (aOR 4.1; 95%CI 1.6, 10.7); while the availability of soap for handwashing at home was protective (aOR 0.41; 95%CI 0.19, 0.87). Those reporting access to a piped water distribution system in the home were twice as likely to report the availability of soap for handwashing. The sensitivity and specificity of the rapid test were 72% (95% CI 47-90) and 71% (95%CI 44-90%). Improving population access to the piped water distribution system and sanitation will likely reduce transmission by enabling enhanced hygiene and limiting the contamination of water sources. The One step V. cholerae O1/O139 Antigen Test is of limited utility for clinical decision making in a hospital setting with access to traditional laboratory methods. Settlement dwellers and mobile populations of all age groups should be targeted for interventions in Papua New Guinea.

Killed oral cholera vaccines: history, development and implementation challenges.

PubMed

Lopez, Anna Lena; Gonzales, Maria Liza Antoinette; Aldaba, Josephine G; Nair, G Balakrish

2014-09-01

Cholera is still a major global health problem, affecting mainly people living in unsanitary conditions and who are at risk for outbreaks of cholera. During the past decade, outbreaks are increasingly reported from more countries. From the early killed oral cholera vaccine, rapid improvements in vaccine development occurred as a result of a better understanding of the epidemiology of the disease, pathogenesis of cholera infection and immunity. The newer-generation oral killed cholera vaccines have been shown to be safe and effective in field trials conducted in cholera endemic areas. Likewise, they have been shown to be protective when used during outbreak settings. Aside from providing direct protection to vaccinated individuals, recent studies have demonstrated that these killed oral vaccines also confer indirect protection through herd immunity. Although new-generation oral cholera vaccines should not be considered in isolation from other preventive approaches in countries where they are most needed, especially improved water quality and sanitation, these vaccines serve as immediately available public health tools for preventing further morbidity and mortality from cholera. However, despite its availability for more than two decades, use of these vaccines has not been optimized. Although there are limitations of the currently available oral cholera vaccines, recent data show that the vaccines are safe, feasible to use even in difficult circumstances and able to provide protection in various settings. Clear identification of the areas and target population groups who will benefit from the use of the cholera vaccines will be required and strategies to facilitate accessibility and usage of these vaccines in these areas and population groups will need to be developed.

HOG MAP kinase regulation of alternariol biosynthesis in Alternaria alternata is important for substrate colonization.

PubMed

Graf, Eva; Schmidt-Heydt, Markus; Geisen, Rolf

2012-07-16

Strains of the genus Alternaria are ubiquitously present and frequently found on fruits, vegetables and cereals. One of the most commonly found species from this genus is A. alternata which is able to produce the mycotoxin alternariol among others. To date only limited knowledge is available about the regulation of the biosynthesis of alternariol, especially under conditions relevant to food. Tomatoes are a typical substrate of A. alternata and have a high water activity. On the other hand cereals with moderate water activity are also frequently colonized by A. alternata. In the current analysis it was demonstrated that even minor changes in the osmotic status of the substrate affect the alternariol biosynthesis of strains from vegetables resulting in nearly complete inhibition. High osmolarity in the environment is usually transmitted to the transcriptional level of downstream regulated genes by the HOG signal cascade (high osmolarity glycerol cascade) which is a MAP kinase transduction pathway. The phosphorylation status of the A. alternata HOG (AaHOG) was determined. Various concentrations of NaCl induce the phosphorylation of AaHOG in a concentration, time and strain dependent manner. A strain with a genetically inactivated aahog gene was no longer able to produce alternariol indicating that the activity of the aahog gene is required for alternariol biosynthesis. Further experiments revealed that the biosynthesis of alternariol is important for the fungus to colonize tomato tissue. The tight water activity dependent regulation of alternariol biosynthesis ensures alternariol biosynthesis at conditions which indicate an optimal colonization substrate for the fungus. Copyright © 2012 Elsevier B.V. All rights reserved.

Vibrio cholerae VciB Mediates Iron Reduction

PubMed Central

Peng, Eric D.

2017-01-01

ABSTRACT Vibrio cholerae is the causative agent of the severe diarrheal disease cholera. V. cholerae thrives within the human host, where it replicates to high numbers, but it also persists within the aquatic environments of ocean and brackish water. To survive within these nutritionally diverse environments, V. cholerae must encode the necessary tools to acquire the essential nutrient iron in all forms it may encounter. A prior study of systems involved in iron transport in V. cholerae revealed the existence of vciB, which, while unable to directly transport iron, stimulates the transport of iron through ferrous (Fe2+) iron transport systems. We demonstrate here a role for VciB in V. cholerae in which VciB stimulates the reduction of Fe3+ to Fe2+, which can be subsequently transported into the cell with the ferrous iron transporter Feo. Iron reduction is independent of functional iron transport but is associated with the electron transport chain. Comparative analysis of VciB orthologs suggests a similar role for other proteins in the VciB family. Our data indicate that VciB is a dimer located in the inner membrane with three transmembrane segments and a large periplasmic loop. Directed mutagenesis of the protein reveals two highly conserved histidine residues required for function. Taken together, our results support a model whereby VciB reduces ferric iron using energy from the electron transport chain. IMPORTANCE Vibrio cholerae is a prolific human pathogen and environmental organism. The acquisition of essential nutrients such as iron is critical for replication, and V. cholerae encodes a number of mechanisms to use iron from diverse environments. Here, we describe the V. cholerae protein VciB that increases the reduction of oxidized ferric iron (Fe3+) to the ferrous form (Fe2+), thus promoting iron acquisition through ferrous iron transporters. Analysis of VciB orthologs in Burkholderia and Aeromonas spp. suggest that they have a similar activity, allowing a

Does Water Hyacinth on East African Lakes Promote Cholera Outbreaks?

PubMed Central

Feikin, Daniel R.; Tabu, Collins W.; Gichuki, John

2010-01-01

Cholera outbreaks continue to occur regularly in Africa. Cholera has been associated with proximity to lakes in East Africa, and Vibrio cholerae has been found experimentally to concentrate on the floating aquatic plant, water hyacinth, which is periodically widespread in East African lakes since the late 1980s. From 1994 to 2008, Nyanza Province, which is the Kenyan province bordering Lake Victoria, accounted for a larger proportion of cholera cases than expected by its population size (38.7% of cholera cases versus 15.3% of national population). Yearly water-hyacinth coverage on the Kenyan section of Lake Victoria was positively associated with the number of cholera cases reported in Nyanza Province (r = 0.83; P = 0.0010). Water hyacinth on freshwater lakes might play a role in initiating cholera outbreaks and causing sporadic disease in East Africa. PMID:20682884

Efficacy of a Single-Dose, Inactivated Oral Cholera Vaccine in Bangladesh.

PubMed

Qadri, Firdausi; Wierzba, Thomas F; Ali, Mohammad; Chowdhury, Fahima; Khan, Ashraful I; Saha, Amit; Khan, Iqbal A; Asaduzzaman, Muhammad; Akter, Afroza; Khan, Arifuzzaman; Begum, Yasmin A; Bhuiyan, Taufiqur R; Khanam, Farhana; Chowdhury, Mohiul I; Islam, Taufiqul; Chowdhury, Atique I; Rahman, Anisur; Siddique, Shah A; You, Young A; Kim, Deok R; Siddik, Ashraf U; Saha, Nirod C; Kabir, Alamgir; Cravioto, Alejandro; Desai, Sachin N; Singh, Ajit P; Clemens, John D

2016-05-05

A single-dose regimen of the current killed oral cholera vaccines that have been prequalified by the World Health Organization would make them more attractive for use against endemic and epidemic cholera. We conducted an efficacy trial of a single dose of the killed oral cholera vaccine Shanchol, which is currently given in a two-dose schedule, in an urban area in which cholera is highly endemic. Nonpregnant residents of Dhaka, Bangladesh, who were 1 year of age or older were randomly assigned to receive a single dose of oral cholera vaccine or oral placebo. The primary outcome was vaccine protective efficacy against culture-confirmed cholera occurring 7 to 180 days after dosing. Prespecified secondary outcomes included protective efficacy against severely dehydrating culture-confirmed cholera during the same interval, against cholera and severe cholera occurring 7 to 90 versus 91 to 180 days after dosing, and against cholera and severe cholera according to age at baseline. A total of 101 episodes of cholera, 37 associated with severe dehydration, were detected among the 204,700 persons who received one dose of vaccine or placebo. The vaccine protective efficacy was 40% (95% confidence interval [CI], 11 to 60%; 0.37 cases per 1000 vaccine recipients vs. 0.62 cases per 1000 placebo recipients) against all cholera episodes, 63% (95% CI, 24 to 82%; 0.10 vs. 0.26 cases per 1000 recipients) against severely dehydrating cholera episodes, and 63% (95% CI, -39 to 90%), 56% (95% CI, 16 to 77%), and 16% (95% CI, -49% to 53%) against all cholera episodes among persons vaccinated at the age of 5 to 14 years, 15 or more years, and 1 to 4 years, respectively, although the differences according to age were not significant (P=0.25). Adverse events occurred at similar frequencies in the two groups. A single dose of the oral cholera vaccine was efficacious in older children (≥5 years of age) and in adults in a setting with a high level of cholera endemicity. (Funded by the Bill

Antimicrobial drugs for treating cholera

PubMed Central

Leibovici-Weissman, Ya'ara; Neuberger, Ami; Bitterman, Roni; Sinclair, David; Salam, Mohammed Abdus; Paul, Mical

2014-01-01

Background Cholera is an acute watery diarrhoea caused by infection with the bacterium Vibrio cholerae, which if severe can cause rapid dehydration and death. Effective management requires early diagnosis and rehydration using oral rehydration salts or intravenous fluids. In this review, we evaluate the additional benefits of treating cholera with antimicrobial drugs. Objectives To quantify the benefit of antimicrobial treatment for patients with cholera, and determine whether there are differences between classes of antimicrobials or dosing schedules. Search methods We searched the Cochrane Infectious Disease Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL); PubMed; EMBASE; African Index Medicus; LILACS; Science Citation Index; metaRegister of Controlled Trials; WHO International Clinical Trials Registry Platform; conference proceedings; and reference lists to March 2014. Selection criteria Randomized and quasi-randomized controlled clinical trials in adults and children with cholera that compared: 1) any antimicrobial treatment with placebo or no treatment; 2) different antimicrobials head-to-head; or 3) different dosing schedules or different durations of treatment with the same antimicrobial. Data collection and analysis Two reviewers independently applied inclusion and exclusion criteria, and extracted data from included trials. Diarrhoea duration and stool volume were defined as primary outcomes. We calculated mean difference (MD) or ratio of means (ROM) for continuous outcomes, with 95% confidence intervals (CI), and pooled data using a random-effects meta-analysis. The quality of evidence was assessed using the GRADE approach. Main results Thirty-nine trials were included in this review with 4623 participants. Antimicrobials versus placebo or no treatment Overall, antimicrobial therapy shortened the mean duration of diarrhoea by about a day and a half compared to placebo or no treatment (MD -36.77 hours, 95% CI -43

Nepalese origin of cholera epidemic in Haiti.

PubMed

Frerichs, R R; Keim, P S; Barrais, R; Piarroux, R

2012-06-01

Cholera appeared in Haiti in October 2010 for the first time in recorded history. The causative agent was quickly identified by the Haitian National Public Health Laboratory and the United States Centers for Disease Control and Prevention as Vibrio cholerae serogroup O1, serotype Ogawa, biotype El Tor. Since then, >500 000 government-acknowledged cholera cases and >7000 deaths have occurred, the largest cholera epidemic in the world, with the real death toll probably much higher. Questions of origin have been widely debated with some attributing the onset of the epidemic to climatic factors and others to human transmission. None of the evidence on origin supports climatic factors. Instead, recent epidemiological and molecular-genetic evidence point to the United Nations peacekeeping troops from Nepal as the source of cholera to Haiti, following their troop rotation in early October 2010. Such findings have important policy implications for shaping future international relief efforts. © 2012 The Authors. Clinical Microbiology and Infection © 2012 European Society of Clinical Microbiology and Infectious Diseases.

Finisher hog production in the Southeastern United States: Ancillary measurements derived from the National Air Emissions Monitoring Study (NAEMS)

NASA Astrophysics Data System (ADS)

Robarge, W. P.; Lee, S.; Walker, J. T.

2010-12-01

Measurements of emissions of gases and fine particulate matter from swine animal feeding operations (AFOs) in the southeastern US have typically been confined to relatively short periods (days to several weeks) and have generally focused on waste lagoons. Access to swine animal housing units and other ancillary information has been limited. The National Air Emissions Monitoring Study (NAEMS) provided a unique opportunity to characterize emissions from swine housing units for an extended period of time (~ 2 years), and allowed access to ancillary measurements regarding nutrient flows (feed amounts and composition), manure dynamics, animal inventories, water usage and farm management. Presented here is a summary of the observations made for a NAEMS finisher site (NC3B) selected as being representative of swine production in the southeastern US. Finisher hogs are raised in rotations (~ 140 days) with a target market weight of 123 kg/hog. Among the population during a rotation (700-800 hogs/barn) the actual growth rate varies with a series of “grade-outs” of market-weight hogs starting ~ 110 days from initial load-in. Derivation of the standing live-weight in the barns during a rotation therefore requires use of a growth model and summation over several different “populations” of hogs within a single barn. Up to 5 different feed formulations are fed during a rotation with %N content ranging from (3.4 to 2.2% N; total feed consumed 181,000 kg/barn). Across 4 complete rotations, N consumed was ~50 g N per hog/day. Of this amount, we estimate ~ 60% is excreted as fecal matter and urine. The TAN (NH3 + NH4+) content of the shallow pits is consistently higher (1880 ±390 mg TAN/L) than that found in the anaerobic lagoon (800 ±70 mg TAN/L), except immediately after recharge following pit-pull (pH of the two liquids was similar). The presence of a recalcitrant layer of sludge in the shallow pits (liquid height = 20 cm; sludge depth = 5-10 cm; TAN = 2500 mg N/L; total

Lipopolysaccharide-specific memory B cell responses to an attenuated live cholera vaccine are associated with protection against Vibrio cholerae infection.

PubMed

Haney, Douglas J; Lock, Michael D; Gurwith, Marc; Simon, Jakub K; Ishioka, Glenn; Cohen, Mitchell B; Kirkpatrick, Beth D; Lyon, Caroline E; Chen, Wilbur H; Sztein, Marcelo B; Levine, Myron M; Harris, Jason B

2018-05-11

The single-dose live attenuated vaccine CVD 103-HgR protects against experimental Vibrio cholerae infection in cholera-naïve adults for at least 6 months after vaccination. While vaccine-induced vibriocidal seroconversion is associated with protection, vibriocidal titers decline rapidly from their peak 1-2 weeks after vaccination. Although vaccine-induced memory B cells (MBCs) might mediate sustained protection in individuals without detectable circulating antibodies, it is unknown whether oral cholera vaccination induces a MBC response. In a study that enrolled North American adults, we measured lipopolysaccharide (LPS)- and cholera toxin (CtxB)-specific MBC responses to PXVX0200 (derived from the CVD 103-HgR strain) and assessed stool volumes following experimental Vibrio cholerae infection. We then evaluated the association between vaccine-induced MBC responses and protection against cholera. There was a significant increase in % CT-specific IgG, % LPS-specific IgG, and % LPS-specific IgA MBCs which persisted 180 days after vaccination as well as a significant association between vaccine-induced increase in % LPS-specific IgA MBCs and lower post-challenge stool volume (r = -0.56, p < 0.001). Oral cholera vaccination induces antigen-specific MBC responses, and the anamnestic LPS-specific responses may contribute to long-term protection and provide correlates of the duration of vaccine-induced protection. NCT01895855. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Improved purification process for cholera toxin and its application to the quantification of residual toxin in cholera vaccines.

PubMed

Jang, Hyun; Kim, Hyo Seung; Kim, Jeong Ah; Seo, Jin Ho; Carbis, Rodney

2009-01-01

A simplified method for the purification of cholera toxin was developed. The 569B strain of Vibrio cholerae, a recognized hyper-producer of cholera toxin, was propagated in a bioreactor under conditions that promote the production of the toxin. The toxin was separated from the bacterial cells using 0.2-microm crossflow microfiltration, the clarified toxin was passed through the membrane into the permeate, and the bacterial cells were retained in the retentate. The 0.2-microm permeate was then concentrated 3-fold and diafiltered against 10 mM phosphate buffer, pH 7.6, using 30-kDa crossflow ultrafiltration. The concentrated toxin was loaded onto a cation exchange column, the toxin was bound to the column, and most of the impurities were passed unimpeded through the column. The toxin was eluted with a salt gradient of phosphate buffer, pH7.0, containing 1.0M NaCl. The peak containing the toxin was assayed for cholera toxin and protein and the purity was determined to be 92%. The toxin peak had a low endotoxin level of 3.1 EU/microg of toxin. The purified toxin was used to prepare antiserum against whole toxin, which was used in a G(M1) ganglioside-binding ELISA to determine residual levels of toxin in an oral inactivated whole-cell cholera vaccine. The G(M1) ganglioside-binding ELISA was shown to be very sensitive and capable of detecting as little as 1 ng/ml of cholera toxin.

Cholera--New York, 1991.

PubMed

1991-08-02

Through June 26, 1991, cholera has been reported from seven countries in the Western Hemisphere: Brazil, Chile, Colombia, Ecuador, Mexico, Peru, and the United States. In the United States, a total of 14 confirmed cases of epidemic-associated cholera have been reported among persons in Florida (one) (1), Georgia (one) (2), New Jersey (eight) (1), and New York (four). This report summarizes information regarding the four cases reported in New York and describes a new laboratory procedure used to confirm the vehicle of transmission in this outbreak.

Cholera risk factors, Papua New Guinea, 2010

PubMed Central

2012-01-01

Background Cholera is newly emergent in Papua New Guinea but may soon become endemic. Identifying the risk factors for cholera provides evidence for targeted prevention and control measures. Methods We conducted a hospital-based case–control study to identify cholera risk factors. Using stool culture as the standard, we evaluated a cholera point of care test in the field. Results 176 participants were recruited: 54 cases and 122 controls. Independent risk factors for cholera were: being over 20 years of age (aOR 2.5; 95%CI 1.1, 5.4), defecating in the open air (or river) (aOR 4.5; 95% CI 1.4, 14.4) and knowing someone who travelled to a cholera affected area (aOR 4.1; 95%CI 1.6, 10.7); while the availability of soap for handwashing at home was protective (aOR 0.41; 95%CI 0.19, 0.87). Those reporting access to a piped water distribution system in the home were twice as likely to report the availability of soap for handwashing. The sensitivity and specificity of the rapid test were 72% (95% CI 47–90) and 71% (95%CI 44–90%). Conclusions Improving population access to the piped water distribution system and sanitation will likely reduce transmission by enabling enhanced hygiene and limiting the contamination of water sources. The One step V. cholerae O1/O139 Antigen Test is of limited utility for clinical decision making in a hospital setting with access to traditional laboratory methods. Settlement dwellers and mobile populations of all age groups should be targeted for interventions in Papua New Guinea. PMID:23126504

Wind direction and its linkage with Vibrio cholerae dissemination.

PubMed

Paz, Shlomit; Broza, Meir

2007-02-01

The relevance of climatic events as causative factors for cholera epidemics is well known. However, examinations of the involvement of climatic factors in intracontinental disease distribution are still absent. The spreading of cholera epidemics may be related to the dominant wind direction over land. We examined the geographic diffusion of three cholera outbreaks through their linkage with the wind direction: a) the progress of Vibrio cholerae O1 biotype El Tor in Africa during 1970-1971 and b) again in 2005-2006; and c) the rapid spread of Vibrio cholerae O139 over India during 1992-1993. We also discuss the possible influence of the wind direction on windborn dissemination by flying insects, which may serve as vectors. Analysis of air pressure data at sea level and at several altitudes over Africa, India, and Bangladesh show a correspondence between the dominant wind direction and the intracontinental spread of cholera. We explored the hypothesis that winds have assisted the progress of cholera Vibrios throughout continents. The current analysis supports the hypothesis that aeroplankton (the tiny life forms that float in the air and that may be caught and carried upward by the wind, landing far from their origin) carry the cholera bacteria from one body of water to an adjacent one. This finding may improve our understanding of how climatic factors are involved in the rapid distribution of new strains throughout a vast continental area. Awareness of the aerial transfer of Vibrio cholerae may assist health authorities by improving the prediction of the disease's geographic dissemination.

Role of the HaHOG1 MAP Kinase in Response of the Conifer Root and But Rot Pathogen (Heterobasidion annosum) to Osmotic and Oxidative Stress

PubMed Central

Raffaello, Tommaso; Keriö, Susanna; Asiegbu, Fred O.

2012-01-01

The basidiomycete Heterobasidion annosum (Fr.) Bref. s.l. is a filamentous white rot fungus, considered to be the most economically important pathogen of conifer trees. Despite the severity of the tree infection, very little is known about the molecular and biochemical aspects related to adaptation to abiotic stresses. In this study, the osmotic and oxidative tolerance as well as the role of the HaHOG1 Mitogen Activated Protein Kinase (MAPK) gene were investigated. The transcript levels of the yeast orthologues GPD1, HSP78, STL1, GRE2 and the ATPase pumps ENA1, PMR1, PMC1 known to have an important role in osmotolerance were also quantified under salt osmotic conditions. The HaHOG1 gene was used for a heterologous expression and functional study in the Saccharomyces cerevisiae Δhog1 strain. Moreover, the phosphorylation level of HaHog1p was studied under salt osmotic and oxidative stress. The result showed that H. annosum displayed a decreased growth when exposed to an increased concentration of osmotic and oxidative stressors. GPD1, HSP78, STL1 and GRE2 showed an induction already at 10 min after exposure to salt stress. Among the ATPase pumps studied, PMC1 was highly induced when the fungus was exposed to 0.2 M CaCl2 for 60 min. The heterologous expression of the HaHOG1 sequence in yeast confirmed that the gene is able to restore the osmotolerance and oxidative tolerance in the S. cerevisiae hog1Δ mutant strain. The HaHog1p was strongly phosphorylated in the presence of NaCl, KCl, H2O2 but not in the presence of CaCl2 and MgCl2. The GFP-HaHog1p fusion protein accumulated in the nuclei of the S. cerevisiae hog1Δ cells when exposed to high osmotic conditions but not under oxidative stress. These results provide the first insights about the response of H. annosum to osmotic and oxidative stress and elucidate the role of the HaHOG1 gene in such conditions. PMID:22319614

Cholera Vaccination Campaign Contributes to Improved Knowledge Regarding Cholera and Improved Practice Relevant to Waterborne Disease in Rural Haiti

PubMed Central

Aibana, Omowunmi; Franke, Molly; Teng, Jessica; Hilaire, Johanne; Raymond, Max; Ivers, Louise C.

2013-01-01

Background Haiti's cholera epidemic has been devastating partly due to underlying weak infrastructure and limited clean water and sanitation. A comprehensive approach to cholera control is crucial, yet some have argued that oral cholera vaccination (OCV) might result in reduced hygiene practice among recipients. We evaluated the impact of an OCV campaign on knowledge and health practice in rural Haiti. Methodology/Principal Findings We administered baseline surveys on knowledge and practice relevant to cholera and waterborne disease to every 10th household during a census in rural Haiti in February 2012 (N = 811). An OCV campaign occurred from May–June 2012 after which we administered identical surveys to 518 households randomly chosen from the same region in September 2012. We compared responses pre- and post-OCV campaign. Post-vaccination, there was improved knowledge with significant increase in percentage of respondents with ≥3 correct responses on cholera transmission mechanisms (odds ratio[OR] 1.91; 95% confidence interval[CI] 1.52–2.40), preventive methods (OR 1.83; 95% CI 1.46–2.30), and water treatment modalities (OR 2.75; 95% CI 2.16–3.50). Relative to pre-vaccination, participants were more likely post-OCV to report always treating water (OR 1.62; 95% CI 1.28–2.05). Respondents were also more likely to report hand washing with soap and water >4 times daily post-vaccine (OR 1.30; 95% CI 1.03–1.64). Knowledge of treating water as a cholera prevention measure was associated with practice of always treating water (OR 1.47; 95% CI 1.14–1.89). Post-vaccination, knowledge was associated with frequent hand washing (OR 2.47; 95% CI 1.35–4.51). Conclusion An OCV campaign in rural Haiti was associated with significant improvement in cholera knowledge and practices related to waterborne disease. OCV can be part of comprehensive cholera control and reinforce, not detract from, other control efforts in Haiti. PMID:24278498

Cholera vaccination campaign contributes to improved knowledge regarding cholera and improved practice relevant to waterborne disease in rural Haiti.

PubMed

Aibana, Omowunmi; Franke, Molly F; Franke, Molly; Teng, Jessica E; Teng, Jessica; Hilaire, Johanne; Raymond, Max; Ivers, Louise C

2013-11-01

Haiti's cholera epidemic has been devastating partly due to underlying weak infrastructure and limited clean water and sanitation. A comprehensive approach to cholera control is crucial, yet some have argued that oral cholera vaccination (OCV) might result in reduced hygiene practice among recipients. We evaluated the impact of an OCV campaign on knowledge and health practice in rural Haiti. We administered baseline surveys on knowledge and practice relevant to cholera and waterborne disease to every 10th household during a census in rural Haiti in February 2012 (N = 811). An OCV campaign occurred from May-June 2012 after which we administered identical surveys to 518 households randomly chosen from the same region in September 2012. We compared responses pre- and post-OCV campaign. Post-vaccination, there was improved knowledge with significant increase in percentage of respondents with ≥ 3 correct responses on cholera transmission mechanisms (odds ratio[OR] 1.91; 95% confidence interval[CI] 1.52-2.40), preventive methods (OR 1.83; 95% CI 1.46-2.30), and water treatment modalities (OR 2.75; 95% CI 2.16-3.50). Relative to pre-vaccination, participants were more likely post-OCV to report always treating water (OR 1.62; 95% CI 1.28-2.05). Respondents were also more likely to report hand washing with soap and water >4 times daily post-vaccine (OR 1.30; 95% CI 1.03-1.64). Knowledge of treating water as a cholera prevention measure was associated with practice of always treating water (OR 1.47; 95% CI 1.14-1.89). Post-vaccination, knowledge was associated with frequent hand washing (OR 2.47; 95% CI 1.35-4.51). An OCV campaign in rural Haiti was associated with significant improvement in cholera knowledge and practices related to waterborne disease. OCV can be part of comprehensive cholera control and reinforce, not detract from, other control efforts in Haiti.

Vibrio cholerae O1 Ogawa Strains Carrying the ctxB7 Allele Caused a Large Cholera Outbreak during 2014 in the Tribal Areas of Odisha, India.

PubMed

Pal, Bibhuti Bhusan; Khuntia, Hemant Kumar; Nayak, Smruti Ranjan; Mohanty, Anima; Biswal, Bhagyalaxmi

2017-09-25

The large outbreak of cholera reported during July to September 2014 in the Narla block of Kalahandi district, India, was investigated to determine the causative organism. Rectal swabs collected from patients with diarrhea and environmental water samples were cultured following standard techniques. The causative organism was identified as Vibrio cholerae O1 Ogawa biotype El Tor, and analysis by double mismatch mutation assay PCR confirmed that all strains were the ctxB7 variant of Haitian V. cholerae O1. The environmental water samples were negative for V. cholerae. The V. cholerae O1 strains were sensitive to tetracycline, ciprofloxacin, norfloxacin, ofloxacin, doxycycline, and azithromycin, but were resistant to erythromycin, gentamicin, chloramphenicol, furazolidone, neomycin, cotrimoxazole, nalidixic acid, and ampicillin. In the 2014 cholera outbreak, the early reporting of the pathogen enabled the government authorities to implement adequate control measures in time to curtail the spread of the disease. That was the second large cholera outbreak due to Haitian variants of V. cholerae O1 after the 2010 Haiti cholera outbreak reported from Odisha, India, and other locations globally. Active surveillance is required to track the spread of this strain in the Odisha region.

Synthesis of protein in intestinal cells exposed to cholera toxin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peterson, J.W.; Berg, W.D. Jr.; Coppenhaver, D.H.

1987-11-01

The mechanism by which cyclic adenosine monophosphate (AMP), formed by intestinal epithelial cells in response to cholera toxin, ultimately results in alterations in water and electrolyte transport is poorly understood. Several studies have indicated that inhibitors of transcription or translation block much of the transport of ions and water in the intestine and edema formation in tissue elicited by cholera toxin. Data presented in this study confirmed the inhibitory effects of cycloheximide on cholera toxin-induced fluid accumulation in the rabbit intestinal loop model. Neither cycloheximide nor actinomycin D altered the amount of cyclic AMP that accumulated in intestinal cells andmore » Chinese hamster ovary cells exposed to cholera toxin. An increase in (/sup 3/H) leucine incorporation was readily demonstrable in intestinal epithelial cells from rabbits challenged with Vibrio cholerae. Similarly, intestinal epithelial cells incubated with cholera toxin for 4 hr synthesized substantially more protein than controls as determined by relative incorporation of (/sup 35/S) methionine. Most of the new protein synthesized in response to cholera toxin was membrane associated and of high molecular weight. The possible significance of the toxin-induced protein relative to cholera pathogenesis was discussed.« less

Insights into Vibrio cholerae Intestinal Colonization from Monitoring Fluorescently Labeled Bacteria

PubMed Central

Millet, Yves A.; Alvarez, David; Ringgaard, Simon; von Andrian, Ulrich H.; Davis, Brigid M.; Waldor, Matthew K.

2014-01-01

Vibrio cholerae, the agent of cholera, is a motile non-invasive pathogen that colonizes the small intestine (SI). Most of our knowledge of the processes required for V. cholerae intestinal colonization is derived from enumeration of wt and mutant V. cholerae recovered from orogastrically infected infant mice. There is limited knowledge of the distribution of V. cholerae within the SI, particularly its localization along the villous axis, or of the bacterial and host factors that account for this distribution. Here, using confocal and intravital two-photon microscopy to monitor the localization of fluorescently tagged V. cholerae strains, we uncovered unexpected and previously unrecognized features of V. cholerae intestinal colonization. Direct visualization of the pathogen within the intestine revealed that the majority of V. cholerae microcolonies attached to the intestinal epithelium arise from single cells, and that there are notable regiospecific aspects to V. cholerae localization and factors required for colonization. In the proximal SI, V. cholerae reside exclusively within the developing intestinal crypts, but they are not restricted to the crypts in the more distal SI. Unexpectedly, V. cholerae motility proved to be a regiospecific colonization factor that is critical for colonization of the proximal, but not the distal, SI. Furthermore, neither motility nor chemotaxis were required for proper V. cholerae distribution along the villous axis or in crypts, suggesting that yet undefined processes enable the pathogen to find its niches outside the intestinal lumen. Finally, our observations suggest that host mucins are a key factor limiting V. cholerae intestinal colonization, particularly in the proximal SI where there appears to be a more abundant mucus layer. Collectively, our findings demonstrate the potent capacity of direct pathogen visualization during infection to deepen our understanding of host pathogen interactions. PMID:25275396

The Hog1p kinase regulates Aft1p transcription factor to control iron accumulation.

PubMed

Martins, Telma S; Pereira, Clara; Canadell, David; Vilaça, Rita; Teixeira, Vítor; Moradas-Ferreira, Pedro; de Nadal, Eulàlia; Posas, Francesc; Costa, Vítor

2018-01-01

Iron acquisition systems have to be tightly regulated to assure a continuous supply of iron, since it is essential for survival, but simultaneously to prevent iron overload that is toxic to the cells. In budding yeast, the low‑iron sensing transcription factor Aft1p is a master regulator of the iron regulon. Our previous work revealed that bioactive sphingolipids modulate iron homeostasis as yeast cells lacking the sphingomyelinase Isc1p exhibit an upregulation of the iron regulon. In this study, we show that Isc1p impacts on iron accumulation and localization. Notably, Aft1p is activated in isc1Δ cells due to a decrease in its phosphorylation and an increase in its nuclear levels. Consistently, the expression of a phosphomimetic version of Aft1p-S210/S224 that favours its nuclear export abolished iron accumulation in isc1Δ cells. Notably, the Hog1p kinase, homologue of mammalian p38, interacts with and directly phosphorylates Aft1p at residues S210 and S224. However, Hog1p-Aft1p interaction decreases in isc1Δ cells, which likely contributes to Aft1p dephosphorylation and consequently to Aft1p activation and iron overload in isc1Δ cells. These results suggest that alterations in sphingolipid composition in isc1Δ cells may impact on iron homeostasis by disturbing the regulation of Aft1p by Hog1p. To our knowledge, Hog1p is the first kinase reported to directly regulate Aft1p, impacting on iron homeostasis. Copyright © 2017 Elsevier B.V. All rights reserved.

Cell Vacuolation Caused by Vibrio cholerae Hemolysin

PubMed Central

Figueroa-Arredondo, Paula; Heuser, John E.; Akopyants, Natalia S.; Morisaki, J. Hiroshi; Giono-Cerezo, Silvia; Enríquez-Rincón, Fernando; Berg, Douglas E.

2001-01-01

Non-O1 strains of Vibrio cholerae implicated in gastroenteritis and diarrhea generally lack virulence determinants such as cholera toxin that are characteristic of epidemic strains; the factors that contribute to their virulence are not understood. Here we report that at least one-third of diarrhea-associated nonepidemic V. cholerae strains from Mexico cause vacuolation of cultured Vero cells. Detailed analyses indicated that this vacuolation was related to that caused by aerolysin, a pore-forming toxin of Aeromonas; it involved primarily the endoplasmic reticulum at early times (∼1 to 4 h after exposure), and resulted in formation of large, acidic, endosome-like multivesicular vacuoles (probably autophagosomes) only at late times (∼16 h). In contrast to vacuolation caused by Helicobacter pylori VacA protein, that induced by V. cholerae was exacerbated by agents that block vacuolar proton pumping but not by endosome-targeted weak bases. It caused centripetal redistribution of endosomes, reflecting cytoplasmic alkalinization. The gene for V. cholerae vacuolating activity was cloned and was found to correspond to hlyA, the structural gene for hemolysin. HlyA protein is a pore-forming toxin that causes ion leakage and, ultimately, eukaryotic cell lysis. Thus, a distinct form of cell vacuolation precedes cytolysis at low doses of hemolysin. We propose that this vacuolation, in itself, contributes to the virulence of V. cholerae strains, perhaps by perturbing intracellular membrane trafficking or ion exchange in target cells and thereby affecting local intestinal inflammatory or other defense responses. PMID:11179335

Cell vacuolation caused by Vibrio cholerae hemolysin.

PubMed

Figueroa-Arredondo, P; Heuser, J E; Akopyants, N S; Morisaki, J H; Giono-Cerezo, S; Enríquez-Rincón, F; Berg, D E

2001-03-01

Non-O1 strains of Vibrio cholerae implicated in gastroenteritis and diarrhea generally lack virulence determinants such as cholera toxin that are characteristic of epidemic strains; the factors that contribute to their virulence are not understood. Here we report that at least one-third of diarrhea-associated nonepidemic V. cholerae strains from Mexico cause vacuolation of cultured Vero cells. Detailed analyses indicated that this vacuolation was related to that caused by aerolysin, a pore-forming toxin of Aeromonas; it involved primarily the endoplasmic reticulum at early times (approximately 1 to 4 h after exposure), and resulted in formation of large, acidic, endosome-like multivesicular vacuoles (probably autophagosomes) only at late times (approximately 16 h). In contrast to vacuolation caused by Helicobacter pylori VacA protein, that induced by V. cholerae was exacerbated by agents that block vacuolar proton pumping but not by endosome-targeted weak bases. It caused centripetal redistribution of endosomes, reflecting cytoplasmic alkalinization. The gene for V. cholerae vacuolating activity was cloned and was found to correspond to hlyA, the structural gene for hemolysin. HlyA protein is a pore-forming toxin that causes ion leakage and, ultimately, eukaryotic cell lysis. Thus, a distinct form of cell vacuolation precedes cytolysis at low doses of hemolysin. We propose that this vacuolation, in itself, contributes to the virulence of V. cholerae strains, perhaps by perturbing intracellular membrane trafficking or ion exchange in target cells and thereby affecting local intestinal inflammatory or other defense responses.

Cholera in pregnancy: Clinical and immunological aspects.

PubMed

Khan, Ashraful I; Chowdhury, Fahima; Leung, Daniel T; Larocque, Regina C; Harris, Jason B; Ryan, Edward T; Calderwood, Stephen B; Qadri, Firdausi

2015-10-01

The objective of this study was to examine the clinical and immunological features of cholera in pregnancy. Women of reproductive age presenting to the icddr,b Dhaka hospital with cholera, and enrolled as part of a larger cohort study, were tested for pregnancy on admission. We compared initial clinical features and immune responses of pregnant patients with non-pregnant female patients at days 2, 7 and 21 after infection. Among reproductive age women enrolled between January 2001 and May 2006, 9.7% (14/144) were pregnant. The duration of diarrhoea prior to admission tended to be higher in pregnant compared to non-pregnant patients (p=0.08), but other clinical characteristics did not differ. Antibody responses to cholera toxin B subunit (CtxB), toxin-coregulated pilus A (TcpA), Vibrio cholerae lipopolysaccharide (LPS), and serum vibriocidal antibody responses, were comparable between pregnant and non-pregnant patients. There were no deaths among the pregnant cases or non-pregnant controls, and no adverse foetal outcomes, including stillbirths, during 21 days of follow up of pregnant cases. To our knowledge, this is the first report of immune responses in pregnant women with cholera. We found that pregnant woman early in pregnancy has comparable clinical illness and subsequent immune responses compared to non-pregnant women. These findings suggest that the evaluation of safety and immunogenicity of oral cholera vaccines in pregnancy should be an area of future investigations. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Characterization of a clinical Vibrio cholerae O139 isolate from Mexico.

PubMed

Parveen, Salina; Farrah, Samuel R; Gonzalez-Bonilla, Celia; Zamudio, Altagracia V; Tamplin, Mark L

2003-01-01

Pathogenic strains of Vibrio cholerae O139 possess the cholera toxin A subunit (ctxA) gene as well as the gene for toxin co-regulated pili (tcpA). We report the isolation of a ctxA-negative, tcpA-negative V. cholerae O139 strain (INDREI) from a patient in Mexico diagnosed with gastrointestinal illness. Certain phenotypic characteristics of this strain were identical to those of V. cholerae O1 biotype El Tor. Unlike ctxA-positive V. cholerae O139 strains, this strain was sensitive to a wide panel of antibiotics, including ampicillin, chloramphenicol, ciprofloxacin, gentamicin, furazolidone, nalidixic acid, nitrofurantoin, tetracycline, trimethoprim-sulfamethoxazole, and streptomycin, but was resistant to polymyxin B. Ribotype and pulsed-field gel electrophoresis profiles of INDRE1 differed from those of ctxA-positive V. cholerae O139 and other V. cholerae strains. Phenotypic characteristics of the Mexico strain were similar to those reported for V. cholerae O139 isolates from Argentina and Sri Lanka.

A novel kit for rapid detection of Vibrio cholerae O1.

PubMed

Hasan, J A; Huq, A; Tamplin, M L; Siebeling, R J; Colwell, R R

1994-01-01

We report on the development and testing of a novel, rapid, colorimetric immunodiagnostic kit, Cholera SMART, for direct detection of the presence of Vibrio cholerae O1 in clinical specimens. Unlike conventional culture methods requiring several days to complete, the Cholera SMART kit can be used directly in the field by untrained or minimally skilled personnel to detect V. cholerae O1 in less than 15 min, without cumbersome laboratory equipment. A total of 120 clinical and environmental bacterial strains, including both O1 and non-O1 serotypes of V. cholerae isolated from samples collected from a variety of geographical regions, were tested, and positive reactions were observed only with V. cholerae O1. Also, results of a field trial in Bangladesh, employing Cholera SMART, showed 100% specificity and 96% sensitivity compared with conventional culture methods. Another field trial, in Mexico, showed that Cholera SMART was 100% in agreement with a recently described coagglutination test when 108 stool specimens were tested.

Are wetlands the reservoir for avian cholera?

USGS Publications Warehouse

Samuel, M.D.; Shadduck, D.J.; Goldberg, Diana R.

2004-01-01

Wetlands have long been suspected to be an important reservoir for Pasteurella multocida and therefore the likely source of avian cholera outbreaks. During the fall of 1995a??98 we collected sediment and water samples from 44 wetlands where avian cholera epizootics occurred the previous winter or spring. We attempted to isolate P. multocida in sediment and surface water samples from 10 locations distributed throughout each wetland. We were not able to isolate P. multocida from any of the 440 water and 440 sediment samples collected from these wetlands. In contrast, during other investigations of avian cholera we isolated P. multocida from 20 of 44 wetlands, including 7% of the water and 4.5% of the sediment samples collected during or shortly following epizootic events. Our results indicate that wetlands are an unlikely reservoir for the bacteria that causes avian cholera.

The protective activity of tea against infection by Vibrio cholerae O1.

PubMed

Toda, M; Okubo, S; Ikigai, H; Suzuki, T; Suzuki, Y; Shimamura, T

1991-02-01

Extracts of black tea exhibited bactericidal activity against Vibrio cholerae O1. The tea extract inhibited the haemolysin activity of V. cholerae O1, El Tor and the morphological changes of Chinese hamster ovary cells induced by cholera toxin. Tea extract also reduced fluid accumulation induced by cholera toxin in sealed adult mice and by V. cholerae O1 in ligated intestinal loops of rabbits. These findings suggest that tea has protective activity against V. cholerae O1.

Population-Level Effect of Cholera Vaccine on Displaced Populations, South Sudan, 2014.

PubMed

Azman, Andrew S; Rumunu, John; Abubakar, Abdinasir; West, Haley; Ciglenecki, Iza; Helderman, Trina; Wamala, Joseph Francis; Vázquez, Olimpia de la Rosa; Perea, William; Sack, David A; Legros, Dominique; Martin, Stephen; Lessler, Justin; Luquero, Francisco J

2016-06-01

Following mass population displacements in South Sudan, preventive cholera vaccination campaigns were conducted in displaced persons camps before a 2014 cholera outbreak. We compare cholera transmission in vaccinated and unvaccinated areas and show vaccination likely halted transmission within vaccinated areas, illustrating the potential for oral cholera vaccine to stop cholera transmission in vulnerable populations.

Surface-attachment sequence in Vibrio Cholerae

NASA Astrophysics Data System (ADS)

Utada, Andrew; Gibiansky, Maxsim; Wong, Gerard

2013-03-01

Vibrio cholerae is a gram-negative bacterium that causes the human disease cholera. It is found natively in brackish costal waters in temperate climates, where it attaches to the surfaces of a variety of different aquatic life. V. cholerae has a single polar flagellum making it highly motile, as well as a number of different pili types, enabling it to attach to both biotic and abiotic surfaces. Using in-house built tracking software we track all surface-attaching bacteria from high-speed movies to examine the early-time attachment profile of v. cholerae onto a smooth glass surface. Similar to previous work, we observe right-handed circular swimming trajectories near surfaces; however, in addition we see a host of distinct motility mechanisms that enable rapid exploration of the surface before forming a more permanent attachment. Using isogenic mutants we show that the motility mechanisms observed are due to a complex combination of hydrodynamics and pili-surface interactions. Lauga, E., DiLuzio, W. R., Whitesides, G. M., Stone, H. A. Biophys. J. 90, 400 (2006).

Molecular tools in understanding the evolution of Vibrio cholerae

PubMed Central

Rahaman, Md. Habibur; Islam, Tarequl; Colwell, Rita R.; Alam, Munirul

2015-01-01

Vibrio cholerae, the etiological agent of cholera, has been a scourge for centuries. Cholera remains a serious health threat for developing countries and has been responsible for millions of deaths globally over the past 200 years. Identification of V. cholerae has been accomplished using a variety of methods, ranging from phenotypic strategies to DNA based molecular typing and currently whole genomic approaches. This array of methods has been adopted in epidemiological investigations, either singly or in the aggregate, and more recently for evolutionary analyses of V. cholerae. Because the new technologies have been developed at an ever increasing pace, this review of the range of fingerprinting strategies, their relative advantages and limitations, and cholera case studies was undertaken. The task was challenging, considering the vast amount of the information available. To assist the study, key references representative of several areas of research are provided with the intent to provide readers with a comprehensive view of recent advances in the molecular epidemiology of V. cholerae. Suggestions for ways to obviate many of the current limitations of typing techniques are also provided. In summary, a comparative report has been prepared that includes the range from traditional typing to whole genomic strategies. PMID:26500613

Conjugated Linoleic Acid Reduces Cholera Toxin Production In Vitro and In Vivo by Inhibiting Vibrio cholerae ToxT Activity.

PubMed

Withey, Jeffrey H; Nag, Drubhajyoti; Plecha, Sarah C; Sinha, Ritam; Koley, Hemanta

2015-12-01

The severe diarrheal disease cholera is endemic in over 50 countries. Current therapies for cholera patients involve oral and/or intravenous rehydration, often combined with the use of antibiotics to shorten the duration and intensity of the disease. However, as antibiotic resistance increases, treatment options will become limited. Linoleic acid has been shown to be a potent negative effector of V. cholerae virulence that acts on the major virulence transcription regulator protein, ToxT, to inhibit virulence gene expression. ToxT activates transcription of the two major virulence factors required for disease, cholera toxin (CT) and toxin-coregulated pilus (TCP). A conjugated form of linoleic acid (CLA) is currently sold over the counter as a dietary supplement and is generally recognized as safe by the U.S. Food and Drug Administration. This study examined whether CLA could be used as a new therapy to reduce CT production, which, in turn, would decrease disease duration and intensity in cholera patients. CLA could be used in place of traditional antibiotics and would be very unlikely to generate resistance, as it affects only virulence factor production and not bacterial growth or survival. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Adapting to the global shortage of cholera vaccines: targeted single dose cholera vaccine in response to an outbreak in South Sudan.

PubMed

Parker, Lucy A; Rumunu, John; Jamet, Christine; Kenyi, Yona; Lino, Richard Laku; Wamala, Joseph F; Mpairwe, Allan M; Ciglenecki, Iza; Luquero, Francisco J; Azman, Andrew S; Cabrol, Jean-Clement

2017-04-01

Shortages of vaccines for epidemic diseases, such as cholera, meningitis, and yellow fever, have become common over the past decade, hampering efforts to control outbreaks through mass reactive vaccination campaigns. Additionally, various epidemiological, political, and logistical challenges, which are poorly documented in the literature, often lead to delays in reactive campaigns, ultimately reducing the effect of vaccination. In June 2015, a cholera outbreak occurred in Juba, South Sudan, and because of the global shortage of oral cholera vaccine, authorities were unable to secure sufficient doses to vaccinate the entire at-risk population-approximately 1 million people. In this Personal View, we document the first public health use of a reduced, single-dose regimen of oral cholera vaccine, and show the details of the decision-making process and timeline. We also make recommendations to help improve reactive vaccination campaigns against cholera, and discuss the importance of new and flexible context-specific dose regimens and vaccination strategies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Use of oral cholera vaccine as a vaccine probe to define the geographical dimensions of person-to-person transmission of cholera.

PubMed

Ali, Mohammad; Kim, Deok Ryun; Kanungo, Suman; Sur, Dipika; Manna, Byomkesh; Digilio, Laura; Dutta, Shanta; Marks, Florian; Bhattacharya, Sujit K; Clemens, John

2018-01-01

Cholera is known to be transmitted from person to person, and inactivated oral cholera vaccines (OCVs) have been shown to confer herd protection via interruption of this transmission. However, the geographic dimensions of chains of person-to-person transmission of cholera are uncertain. The ability of OCVs to confer herd protection was used to define these dimensions in two cholera-endemic settings, one in rural Bangladesh and the other in urban India. Two large randomized, placebo-controlled trials of inactivated OCVs, one in rural Matlab, Bangladesh and the other in urban Kolkata, India, were reanalyzed. Vaccine herd protection was evaluated by relating the risk of cholera in placebo recipients to vaccine coverage of surrounding residents residing within concentric rings. In Matlab, concentric rings in 100-m increments up to 700m were evaluated; in Kolkata, 50-m increments up to 350m were evaluated. One hundred and eight cholera cases among 24667 placebo recipients were detected during 1year of post-vaccination follow-up at Matlab; 128 cholera cases among 34968 placebo recipients were detected during 3 years of follow-up in Kolkata. Consistent inverse relationships were observed between vaccine coverage of the ring and the risk of cholera in the central placebo recipient for rings with radii up to 500m in Matlab and up to 150m in Kolkata. These results suggest that the dimensions of chains of person-to-person transmission in endemic settings can be quite large and may differ substantially from setting to setting. Using OCVs as 'probes' to define these dimensions can inform geographical targeting strategies for the deployment of these vaccines in endemic settings. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Survivability and molecular variation in Vibrio cholerae from epidemic sites in China.

PubMed

Li, X Q; Wang, M; Deng, Z A; Shen, J C; Zhang, X Q; Liu, Y F; Cai, Y S; Wu, X W; DI, B

2015-01-01

The survival behaviour of Vibrio cholerae in cholera epidemics, together with its attributes of virulence-associated genes and molecular fingerprints, are significant for managing cholera epidemics. Here, we selected five strains representative of V. cholerae O1 and O139 involved in cholera events, examined their survival capacity in large volumes of water sampled from epidemic sites of a 2005 cholera outbreak, and determined virulence-associated genes and molecular subtype changes of the surviving isolates recovered. The five strains exhibited different survival capacities varying from 17 to 38 days. The virulence-associated genes of the surviving isolates remained unchanged, while their pulsotypes underwent slight variation. In particular, one waterway-isolated strain maintained virulence-associated genes and evolved to share the same pulsotype as patient strains, highlighting its role in the cholera outbreak. The strong survival capacity and molecular attributes of V. cholerae might account for its persistence in environmental waters and the long duration of the cholera outbreak, allowing effective control measures.

Effectiveness of mass oral cholera vaccination in Beira, Mozambique.

PubMed

Lucas, Marcelino E S; Deen, Jacqueline L; von Seidlein, Lorenz; Wang, Xuan-Yi; Ampuero, Julia; Puri, Mahesh; Ali, Mohammad; Ansaruzzaman, M; Amos, Juvenaldo; Macuamule, Arminda; Cavailler, Philippe; Guerin, Philippe J; Mahoudeau, Claude; Kahozi-Sangwa, Pierre; Chaignat, Claire-Lise; Barreto, Avertino; Songane, Francisco F; Clemens, John D

2005-02-24

New-generation, orally administered cholera vaccines offer the promise of improved control of cholera in sub-Saharan Africa. However, the high prevalence of human immunodeficiency virus (HIV) infection in many cholera-affected African populations has raised doubts about the level of protection possible with vaccination. We evaluated a mass immunization program with recombinant cholera-toxin B subunit, killed whole-cell (rBS-WC) oral cholera vaccine in Beira, Mozambique, a city where the seroprevalence of HIV is 20 to 30 percent. From December 2003 to January 2004, we undertook mass immunization of nonpregnant persons at least two years of age, using a two-dose regimen of rBS-WC vaccine in Esturro, Beira (population 21,818). We then assessed vaccine protection in a case-control study during an outbreak of El Tor Ogawa cholera in Beira between January and May 2004. To estimate the level of vaccine protection, antecedent rates of vaccination were compared between persons with culture-confirmed cholera severe enough to have prompted them to seek treatment and age- and sex-matched neighborhood controls without treated diarrhea. We assessed the effectiveness of the vaccine in 43 persons with cholera and 172 controls. Receipt of one or more doses of rBS-WC vaccine was associated with 78 percent protection (95 percent confidence interval, 39 to 92 percent; P=0.004). The vaccine was equally effective in children younger than five years of age and in older persons. A concurrently conducted case-control study designed to detect bias compared persons with treated, noncholeraic diarrhea and controls without diarrhea in the same population and found no protection associated with receipt of the rBS-WC vaccine. The rBS-WC vaccine was highly effective against clinically significant cholera in an urban sub-Saharan African population with a high prevalence of HIV infection. Copyright 2005 Massachusetts Medical Society.

Cholera in travelers: shifting tides in epidemiology, management, and prevention.

PubMed

Fillion, Katie; Mileno, Maria D

2015-01-01

The distribution of cholera's devastating effects has changed. While cholera is endemic in 50 countries mostly in Asia and Africa, more than half of the cases reported in 2012 were in the Western Hemisphere, predominantly Haiti. Since the current epidemic began in Haiti in 2010, there has been spread to the Dominican Republic, Cuba, and most recently Mexico. Several recent case reports document individuals returning home from affected areas with diarrhea from cholera, in some cases severe. Hopeful news reported the containment of an outbreak through the use of a Vibrio cholera vaccine. There are safe and effective oral cholera vaccines available and recommended in outbreaks and endemic areas, although they are not currently available in the USA or to travelers. This review aims to discuss the latest data to aid our current recommendations for the prevention of cholera in travelers beyond standard personal and food hygiene precautions for the prevention of travelers' diarrhea and to offer insights on the most current data available about cholera vaccine progress and potential use.

Chlorination of Household Drinking Water Among Cholera Patients' Households to Prevent Transmission of Toxigenic Vibrio cholerae in Dhaka, Bangladesh: CHoBI7 Trial.

PubMed

Rashid, Mahamud-Ur; George, Christine Marie; Monira, Shirajum; Mahmud, Toslim; Rahman, Zillur; Mustafiz, Munshi; Saif-Ur-Rahman, K M; Parvin, Tahmina; Bhuyian, Sazzadul Islam; Zohura, Fatema; Begum, Farzana; Biswas, Shwapon Kumar; Akhter, Shamima; Zhang, Xiaotong; Sack, David; Sack, R Bradley; Alam, Munirul

2016-12-07

Household members of cholera patients are at a 100 times higher risk of cholera infections than the general population because of shared contaminated drinking water sources and secondary transmission through poor household hygiene practices. In this study, we investigated the bactericidal concentration of free chlorine required to inactivate Vibrio cholerae in household drinking water in Dhaka, Bangladesh. In laboratory experiments, we found that the concentrations of free chlorine required to inactivate 10 5 colony-forming units (CFU)/mL of V. cholerae serogroups O1 and O139 were 0.1 mg/L and 0.2 mg/L, respectively. The concentration of free chlorine generated by a single chlorine tablet (sodium dichloroisocyanurate [33 mg]) after a 30-minute reaction time in a 10-L sealed vessel containing Dhaka city municipal supply water was 1.8 mg/L; and the concentration declined to 0.26 mg/L after 24 hours. In field measurements, water collected from 165 households enrolled in a randomized controlled trial (RCT) of a chlorine and handwashing with soap intervention (Cholera-Hospital-Based-Intervention-for-7-Days [CHoBI7]), we observed significantly higher free chlorine concentrations in the 82 intervention arm households (mean = 1.12 mg/L, standard deviation [SD] = 0.52, range = 0.07-2.6 mg/L) compared with the 83 control households (0.017 mg/L, SD = 0.01, range = 0-0.06 mg/L) (P < 0.001) during spot check visits. These findings suggest that point-of-use chlorine tablets present an effective approach to inactivate V. cholerae from drinking water in households of cholera patients in Dhaka city. This result is consistent with the findings from the RCT of CHoBI7 which found that this intervention led to a significant reduction in symptomatic cholera infections among household members of cholera patients and no stored drinking water samples with detectable V. cholerae. © The American Society of Tropical Medicine and Hygiene.

Chlorination of Household Drinking Water among Cholera Patients' Households to Prevent Transmission of Toxigenic Vibrio cholerae in Dhaka, Bangladesh: CHoBI7 Trial

PubMed Central

Rashid, Mahamud-ur; George, Christine Marie; Monira, Shirajum; Mahmud, Toslim; Rahman, Zillur; Mustafiz, Munshi; Saif-Ur-Rahman, K. M.; Parvin, Tahmina; Bhuyian, Sazzadul Islam; Zohura, Fatema; Begum, Farzana; Biswas, Shwapon Kumar; Akhter, Shamima; Zhang, Xiaotong; Sack, David; Sack, R. Bradley; Alam, Munirul

2016-01-01

Household members of cholera patients are at a 100 times higher risk of cholera infections than the general population because of shared contaminated drinking water sources and secondary transmission through poor household hygiene practices. In this study, we investigated the bactericidal concentration of free chlorine required to inactivate Vibrio cholerae in household drinking water in Dhaka, Bangladesh. In laboratory experiments, we found that the concentrations of free chlorine required to inactivate 105 colony-forming units (CFU)/mL of V. cholerae serogroups O1 and O139 were 0.1 mg/L and 0.2 mg/L, respectively. The concentration of free chlorine generated by a single chlorine tablet (sodium dichloroisocyanurate [33 mg]) after a 30-minute reaction time in a 10-L sealed vessel containing Dhaka city municipal supply water was 1.8 mg/L; and the concentration declined to 0.26 mg/L after 24 hours. In field measurements, water collected from 165 households enrolled in a randomized controlled trial (RCT) of a chlorine and handwashing with soap intervention (Cholera-Hospital-Based-Intervention-for-7-Days[CHoBI7]), we observed significantly higher free chlorine concentrations in the 82 intervention arm households (mean = 1.12 mg/L, standard deviation [SD] = 0.52, range = 0.07–2.6 mg/L) compared with the 83 control households (0.017 mg/L, SD = 0.01, range = 0–0.06 mg/L) (P < 0.001) during spot check visits. These findings suggest that point-of-use chlorine tablets present an effective approach to inactivate V. cholerae from drinking water in households of cholera patients in Dhaka city. This result is consistent with the findings from the RCT of CHoBI7 which found that this intervention led to a significant reduction in symptomatic cholera infections among household members of cholera patients and no stored drinking water samples with detectable V. cholerae. PMID:27698273

Cholera Epidemic - Lusaka, Zambia, October 2017-May 2018.

PubMed

Sinyange, Nyambe; Brunkard, Joan M; Kapata, Nathan; Mazaba, Mazyanga Lucy; Musonda, Kunda G; Hamoonga, Raymond; Kapina, Muzala; Kapaya, Fred; Mutale, Lwito; Kateule, Ernest; Nanzaluka, Francis; Zulu, James; Musyani, Chileshe Lukwesa; Winstead, Alison V; Davis, William W; N'cho, Hammad S; Mulambya, Nelia L; Sakubita, Patrick; Chewe, Orbie; Nyimbili, Sulani; Onwuekwe, Ezinne V C; Adrien, Nedghie; Blackstock, Anna J; Brown, Travis W; Derado, Gordana; Garrett, Nancy; Kim, Sunkyung; Hubbard, Sydney; Kahler, Amy M; Malambo, Warren; Mintz, Eric; Murphy, Jennifer; Narra, Rupa; Rao, Gouthami G; Riggs, Margaret A; Weber, Nicole; Yard, Ellen; Zyambo, Khozya D; Bakyaita, Nathan; Monze, Namani; Malama, Kennedy; Mulwanda, Jabbin; Mukonka, Victor M

2018-05-18

On October 6, 2017, an outbreak of cholera was declared in Zambia after laboratory confirmation of Vibrio cholerae O1, biotype El Tor, serotype Ogawa, from stool specimens from two patients with acute watery diarrhea. The two patients had gone to a clinic in Lusaka, the capital city, on October 4. Cholera cases increased rapidly, from several hundred cases in early December 2017 to approximately 2,000 by early January 2018 (Figure). In collaboration with partners, the Zambia Ministry of Health (MoH) launched a multifaceted public health response that included increased chlorination of the Lusaka municipal water supply, provision of emergency water supplies, water quality monitoring and testing, enhanced surveillance, epidemiologic investigations, a cholera vaccination campaign, aggressive case management and health care worker training, and laboratory testing of clinical samples. In late December 2017, a number of water-related preventive actions were initiated, including increasing chlorine levels throughout the city's water distribution system and placing emergency tanks of chlorinated water in the most affected neighborhoods; cholera cases declined sharply in January 2018. During January 10-February 14, 2018, approximately 2 million doses of oral cholera vaccine were administered to Lusaka residents aged ≥1 year. However, in mid-March, heavy flooding and widespread water shortages occurred, leading to a resurgence of cholera. As of May 12, 2018, the outbreak had affected seven of the 10 provinces in Zambia, with 5,905 suspected cases and a case fatality rate (CFR) of 1.9%. Among the suspected cases, 5,414 (91.7%), including 98 deaths (CFR = 1.8%), occurred in Lusaka residents.

Cholera, canals, and contagion: Rediscovering Dr. Beck's report.

PubMed

Tuite, Ashleigh R; Chan, Christina H; Fisman, David N

2011-08-01

Cholera first appeared in North America (in Montreal and Quebec) in 1832 and spread rapidly across the eastern half of the continent. The dispatch of American disease control experts to Lower Canada in anticipation of cholera's spread implies that medical professionals expected spread, possibly from contagion, even though the notion that cholera was contagious was disparaged in medical writings of the time, and would be until John Snow's landmark work in London in the 1850s. Snow's insights derived largely from his observations on spatial and temporal patterns of cholera cases. We discuss a document from the 1832 epidemic, the report of Dr. Lewis Beck to New York's Governor Throop, which anticipates Snow in presenting geospatial data that imply cholera's contagiousness. Beck shows that the movements of immigrants along the newly completed New York state canal system resulted in sequential cholera outbreaks along the canal's path. Although aware of the degree to which this suggested contagion, Beck argues strenuously against the contagiousness of cholera. We explore the social context of early nineteenth-century medicine that probably led Beck to disbelieve his own observations, and to favor a medical model inconsistent with his data. Themes that emerge from our inquiry include belief in disease as a physical manifestation of defective morality, stigmatization of the poor and immigrant groups, and reluctance to overturn prevailing medical models that themselves reflected the economic position of medical practitioners. We show that these themes continue to serve as obstacles to innovation in medical and public health practice today.

Influence of human behavior on cholera dynamics

PubMed Central

Wang, Xueying; Gao, Daozhou; Wang, Jin

2015-01-01

This paper is devoted to studying the impact of human behavior on cholera infection. We start with a cholera ordinary differential equation (ODE) model that incorporates human behavior via modeling disease prevalence dependent contact rates for direct and indirect transmissions and infectious host shedding. Local and global dynamics of the model are analyzed with respect to the basic reproduction number. We then extend the ODE model to a reaction-convection-diffusion partial differential equation (PDE) model that accounts for the movement of both human hosts and bacteria. Particularly, we investigate the cholera spreading speed by analyzing the traveling wave solutions of the PDE model, and disease threshold dynamics by numerically evaluating the basic reproduction number of the PDE model. Our results show that human behavior can reduce (a) the endemic and epidemic levels, (b) cholera spreading speeds and (c) the risk of infection (characterized by the basic reproduction number). PMID:26119824

Pigs immunized with a novel E2 subunit vaccine are protected from heterologous classical swine fever virus challenge

USDA-ARS?s Scientific Manuscript database

Background: Classical swine fever (CSF) or hog cholera is a highly contagious swineviral disease. CSF endemic countries have to use routine vaccination with modifiedlive virus (MLV) vaccines to prevent and control CSF. However, it is impossible toserologically differentiate MLV vaccinated pigs from...

[Identification of Vibrio cholerae O1 by flow cytometry].

PubMed

Alvarado-Alemán, F J; González-Bonilla, C; Wong-Arambula, C; Gutiérrez-Cogco, L; Sepúlveda-Amor, J; Kumate-Rodríguez, J

1994-01-01

A total of 72 peptonated water samples suspected of carrying Vibrio cholerae were assessed by laser flow cytometry (LFC) and compared with positive culture. We used a direct fluorescence technique using polyclonal (PolAb) and monoclonal antibodies (MoAb) conjugated to fluorescein. The PolAb were able to detect 33 positive samples. A clear difference among the 20 positive samples was found with only three V. cholerae O1 false negatives when MoAb were used whereas all 13 V. cholerae Non O1 samples were detected. The correlation index comparing control autofluorescence with peptonated water samples show a R = 0.69, versus 0.96 with pure V. cholerae O1 strains. Our data suggest that the LFC technique is able to recognize V. cholerae O1 from a mixture of microorganisms with high sensitivity and specificity in a few hours.

Hydroclimatic Extremes and Cholera Dynamics in the 21st Century

NASA Astrophysics Data System (ADS)

Akanda, A. S.; Jutla, A. S.; Islam, S.

2012-12-01

Cholera, an acute water-borne diarrheal illness, has reemerged as a significant health threat across much of the developing world. Despite major advances in the ecological and the microbiological understanding of the causative agent, V. cholerae, the role of the underlying climatic and environmental processes in propagating transmission is not adequately understood. Recent findings suggest a more prominent role of hydroclimatic extremes - droughts and floods - on the unique dual cholera peaks in the Bengal Delta region of South Asia, the native homeland of cholera. Increasing water scarcity and abundance, and coastal sea-level rise, influenced by changing climate patterns and large-scale climatic phenomena, is likely to adversely impact cholera transmission in South Asia. We focus on understanding how associated changes in macro-scale conditions in this region will impact micro-scale processes related to cholera in coming decades. We use the PRECIS Regional Climate Model over the Ganges-Brahmaputra-Meghna (GBM) basin region to simulate detailed high resolution projections of climate patterns for the 21st century. Precipitation outputs are analyzed for the 1980-2040 period to identify the trends and changes in hydroclimatic extremes and potential impacts on cholera dynamics over the next three decades (2010-2040), in relation to the cholera surveillance operations over the past three decades (1980-2010). We find that an increased number of extreme precipitation events with prolonged dry periods in the Ganges basin region will likely adversely affect dry season cholera outbreaks. Increased monsoon precipitation volumes in the Brahmaputra basin catchments are likely to cause record floods and subsequently trigger large epidemics in downstream areas. Our results provide new insight by identifying the changes in the two distinctly different, pre and post monsoon, cholera transmission mechanisms related to large-scale climatic controls that prevail in the region. A

Isolation of isoelectrically pure cholera toxin for crystallization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spangler, B.D.; Westbrook, E.M.

1989-01-01

We have determined that the failure of cholera toxin to crystallize well results from its isoelectric heterogeneity, which is probably due to a post-translational process such as deamidation of its B subunit. Every sample of cholera toxin we have examined from commercial or academic suppliers has been heterogeneous; heterogeneous cholera toxin does not crystallize satisfactorily. We have overcome this problem by using ion-exchange fast protein liquid chromatography (FPLC) to obtain an isoelectrically homogeneous species of cholera toxin. Homogeneous cholera toxin crystallizes readily, forming single, nonmosaic crystals suitable for x-ray diffraction studies. For this process, protein was applied to a MonoQmore » ion-exchange column, then eluted with an isocratic low salt buffer followed by a linear salt gradient (0-100 mM NaCl). Column fractions were analyzed on isoelectric focusing gels, and those fractions containing the desired homogeneous species were pooled and concentrated. Crystals formed within 24 to 48 hours in a MOPS/PEG buffer, which made use of slow isoelectric precipitation to induce crystallization. 23 refs., 6 figs.« less

Cholera epidemic in Yemen, 2016-18: an analysis of surveillance data.

PubMed

Camacho, Anton; Bouhenia, Malika; Alyusfi, Reema; Alkohlani, Abdulhakeem; Naji, Munna Abdulla Mohammed; de Radiguès, Xavier; Abubakar, Abdinasir M; Almoalmi, Abdulkareem; Seguin, Caroline; Sagrado, Maria Jose; Poncin, Marc; McRae, Melissa; Musoke, Mohammed; Rakesh, Ankur; Porten, Klaudia; Haskew, Christopher; Atkins, Katherine E; Eggo, Rosalind M; Azman, Andrew S; Broekhuijsen, Marije; Saatcioglu, Mehmet Akif; Pezzoli, Lorenzo; Quilici, Marie-Laure; Al-Mesbahy, Abdul Rahman; Zagaria, Nevio; Luquero, Francisco J

2018-06-01

In war-torn Yemen, reports of confirmed cholera started in late September, 2016. The disease continues to plague Yemen today in what has become the largest documented cholera epidemic of modern times. We aimed to describe the key epidemiological features of this epidemic, including the drivers of cholera transmission during the outbreak. The Yemen Health Authorities set up a national cholera surveillance system to collect information on suspected cholera cases presenting at health facilities. Individual variables included symptom onset date, age, severity of dehydration, and rapid diagnostic test result. Suspected cholera cases were confirmed by culture, and a subset of samples had additional phenotypic and genotypic analysis. We first conducted descriptive analyses at national and governorate levels. We divided the epidemic into three time periods: the first wave (Sept 28, 2016, to April 23, 2017), the increasing phase of the second wave (April 24, 2017, to July 2, 2017), and the decreasing phase of the second wave (July 3, 2017, to March 12, 2018). We reconstructed the changes in cholera transmission over time by estimating the instantaneous reproduction number, R t . Finally, we estimated the association between rainfall and the daily cholera incidence during the increasing phase of the second epidemic wave by fitting a spatiotemporal regression model. From Sept 28, 2016, to March 12, 2018, 1 103 683 suspected cholera cases (attack rate 3·69%) and 2385 deaths (case fatality risk 0·22%) were reported countrywide. The epidemic consisted of two distinct waves with a surge in transmission in May, 2017, corresponding to a median R t of more than 2 in 13 of 23 governorates. Microbiological analyses suggested that the same Vibrio cholerae O1 Ogawa strain circulated in both waves. We found a positive, non-linear, association between weekly rainfall and suspected cholera incidence in the following 10 days; the relative risk of cholera after a weekly rainfall of 25

Estimating effects of improved drinking water and sanitation on cholera.

PubMed

Leidner, Andrew J; Adusumilli, Naveen C

2013-12-01

Demand for adequate provision of drinking-water and sanitation facilities to promote public health and economic growth is increasing in the rapidly urbanizing countries of the developing world. With a panel of data on Asia and Africa from 1990 to 2008, associations are estimated between the occurrence of cholera outbreaks, the case rates in given outbreaks, the mortality rates associated with cholera and two disease control mechanisms, drinking-water and sanitation services. A statistically significant and negative effect is found between drinking-water services and both cholera case rates as well as cholera-related mortality rates. A relatively weak statistical relationship is found between the occurrence of cholera outbreaks and sanitation services.

Outbreak-associated Vibrio cholerae genotypes with identical pulsotypes, Malaysia, 2009.

PubMed

Teh, Cindy Shuan Ju; Suhaili, Zarizal; Lim, King Ting; Khamaruddin, Muhamad Afif; Yahya, Fariha; Sajili, Mohd Hailmi; Yeo, Chew Chieng; Thong, Kwai Lin

2012-07-01

A cholera outbreak in Terengganu, Malaysia, in November 2009 was caused by 2 El Tor Vibrio cholerae variants resistant to typical antimicrobial drugs. Evidence of replacement of treatable V. cholerae infection in the region with antimicrobial-resistant strains calls for increased surveillance and prevention measures.

78 FR 45057 - Safety Zone; Alpena Area HOG Rally Fireworks, Alpena, Michigan

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-26

...-AA00 Safety Zone; Alpena Area HOG Rally Fireworks, Alpena, Michigan AGENCY: Coast Guard, DHS. ACTION... rally in Alpena, Michigan with a fireworks display. Fireworks will be launched near the end of Mason Street, South of State Avenue, approximately 50 yards west of Thunder Bay in Alpena, Michigan. The...

Role of phytoplankton in maintaining endemicity and seasonality of cholera in Bangladesh.

PubMed

Islam, M Sirajul; Islam, M Shafiqul; Mahmud, Zahid H; Cairncross, Sandy; Clemens, John D; Collins, Andrew E

2015-09-01

In Bangladesh, cholera is endemic and maintains a regular seasonal pattern. The role of phytoplankton in maintaining endemicity and seasonality of cholera was monitored in Matlab, Bangladesh. Phytoplankton and water samples were collected from two ponds bi-weekly for 1 year. The association of Vibrio cholerae O1 with phytoplankton was studied by culture and direct fluorescent antibody techniques. The bio-physicochemical parameters of water were measured and data for cases of cholera were collected from the records of Matlab hospital. The correlation of cholera cases with levels of phytoplankton, V. cholerae and bio-physicochemical parameters of water was carried out using Pearson's correlation coefficients. V. cholerae O1 survived for 48 days in association with Anabaena variabilis in a culturable state, but survived for a year in a viable but non-culturable (VBNC) state. V. cholerae survived for 12 and 32 days in a culturable state in control water (without algae) and water with algae, respectively. There was a significant correlation between changing levels of cholera cases in the community and the blue green algae and total phytoplankton in the aquatic environment. A significant correlation was also found between the cholera cases and chlorophyll-a and VBNC V. cholerae O1 in the aquatic environment. This study demonstrated the role of phytoplankton in maintaining endemicity and seasonality of cholera in Bangladesh. © The Author 2015. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Outbreak-associated Vibrio cholerae Genotypes with Identical Pulsotypes, Malaysia, 2009

PubMed Central

Teh, Cindy Shuan Ju; Suhaili, Zarizal; Lim, King Ting; Khamaruddin, Muhamad Afif; Yahya, Fariha; Sajili, Mohd Hailmi; Yeo, Chew Chieng

2012-01-01

A cholera outbreak in Terengganu, Malaysia, in November 2009 was caused by 2 El Tor Vibrio cholerae variants resistant to typical antimicrobial drugs. Evidence of replacement of treatable V. cholerae infection in the region with antimicrobial-resistant strains calls for increased surveillance and prevention measures. PMID:22709679

Expression of accessory colonization factor subunit A (ACFA) of Vibrio cholerae and ACFA fused to cholera toxin B subunit in transgenic tomato (Solanum lycopersicum).

PubMed

Sharma, Manoj Kumar; Jani, Dewal; Thungapathra, M; Gautam, J K; Meena, L S; Singh, Yogendra; Ghosh, Amit; Tyagi, Akhilesh Kumar; Sharma, Arun Kumar

2008-05-20

In earlier study from our group, cholera toxin B subunit had been expressed in tomato for developing a plant-based vaccine against cholera. In the present investigation, gene for accessory colonization factor (acf) subunit A, earlier reported to be essential for efficient colonization in the intestine, has been expressed in Escherichia coli as well as tomato plants. Gene encoding for a chimeric protein having a fusion of cholera toxin B subunit and accessory colonization factor A was also expressed in tomato to generate more potent combinatorial antigen. CaMV35S promoter with a duplicated enhancer sequence was used for expression of these genes in tomato. Integration of transgenes into tomato genome was confirmed by PCR and Southern hybridization. Expression of the genes was confirmed at transcript and protein levels. Accessory colonization factor A and cholera toxin B subunit fused to this protein accumulated up to 0.25% and 0.08% of total soluble protein, respectively, in the fruits of transgenic plants. Whereas protein purified from E. coli, in combination with cholera toxin B subunit can be used for development of conventional subunit vaccine, tomato fruits expressing these proteins can be used together with tomato plants expressing cholera toxin B subunit for development of oral vaccine against cholera.

Cholera toxin structure, gene regulation and pathophysiological and immunological aspects.

PubMed

Sánchez, J; Holmgren, J

2008-05-01

Many notions regarding the function, structure and regulation of cholera toxin expression have remained essentially unaltered in the last 15 years. At the same time, recent findings have generated additional perspectives. For example, the cholera toxin genes are now known to be carried by a non-lytic bacteriophage, a previously unsuspected condition. Understanding of how the expression of cholera toxin genes is controlled by the bacterium at the molecular level has advanced significantly and relationships with cell-density-associated (quorum-sensing) responses have recently been discovered. Regarding the cell intoxication process, the mode of entry and intracellular transport of cholera toxin are becoming clearer. In the immunological field, the strong oral immunogenicity of the non-toxic B subunit of cholera toxin (CTB) has been exploited in the development of a now widely licensed oral cholera vaccine. Additionally, CTB has been shown to induce tolerance against co-administered (linked) foreign antigens in some autoimmune and allergic diseases.

Cholera Vaccination in Urban Haiti

PubMed Central

Rouzier, Vanessa; Severe, Karine; Juste, Marc Antoine Jean; Peck, Mireille; Perodin, Christian; Severe, Patrice; Deschamps, Marie Marcelle; Verdier, Rose Irene; Prince, Sabine; Francois, Jeannot; Cadet, Jean Ronald; Guillaume, Florence D.; Wright, Peter F.; Pape, Jean W.

2013-01-01

Successful and sustained efforts have been made to curtail the major cholera epidemic that occurred in Haiti in 2010 with the promotion of hygiene and sanitation measures, training of health personnel and establishment of treatment centers nationwide. Oral cholera vaccine (OCV) was introduced by the Haitian Ministry of Health as a pilot project in urban and rural areas. This paper reports the successful OCV pilot project led by GHESKIO Centers in the urban slums of Port-au-Prince where 52,357 persons received dose 1 and 90.8% received dose 2; estimated coverage of the at-risk community was 75%. This pilot study demonstrated the effort, community mobilization, and organizational capacity necessary to achieve these results in a challenging setting. The OCV intervention paved the way for the recent launching of a national cholera vaccination program integrated in a long-term ambitious and comprehensive plan to address Haiti's critical need in water security and sanitation. PMID:24106194

Endemicity and epidemicity of cholera

PubMed Central

Kamal, A. M.

1963-01-01

In this review of the factors governing the endemicity and epidemicity of cholera, special attention is paid to attempts to demarcate endemic areas by statistical methods, in particular by the use of Swaroop's “index of endemicity”. Once such areas are delineated, it is possible to assess the characteristic features—such as the presence of numerous water tanks, the heavy pollution of water in the dry season, and socio-cultural factors—which help to maintain continuity of infection. While some of the causes underlying epidemic outbreaks of cholera are still obscure, it is clear that these outbreaks derive in large part from the introduction of infection into communities whose members have no immunity (or have lost their immunity) to cholera, and that a very important role is played here by movements of groups of the population—particularly, in India, the movement of pilgrims and others to and from fairs and festivals. PMID:14030417

[Cytotoxic effect of Vibrio cholerae non-O1 on Vero cells].

PubMed

Figueroa-Arredondo, P; García-Lozano, H; Gutiérrez-Cogco, L; Valdespino-Gómez, J L

1994-01-01

At the present time there is still in Mexico a diarrhoeal outbreak due to Vibrio cholerae O1. In INDRE we have isolated from the same outbreak last year (jan-apr), 70 strains of Vibrio cholerae Non-O1. These were isolated from patients with a diarrhoeal illness different from cholera. Patients were of different ages and sex, and from various geographic areas. The isolated strains were confirmed by serological agglutination test with polyclonal antisera, and they neither belong to O1 serogroup or O139. We assayed all the 70 strains in Vero cells, searching for cytotoxic effect, probably attributed to cholera toxin, or any other toxin. The strains were screened by PCR for cholera toxin gene detection, and negative results were obtained. We have found only one CT-producer strain, but it was a rough one so, we are not able to affirm that is not a V. cholerae O1 serotype. Vibrio cholerae Non-O1 strains, tested in Vero cells assay, produced cytotoxic effect within 24 h. It was found that 48/70 strains (66.6%), had cytotoxic activity, showing rounding and then lysis of cells. From our results we concluded that this cytotoxic effect, is not cholera toxin related, instead we propose it could be due to an unknown virulence factor, probably a different toxin in mexican Vibrio cholerae Non-O1 strains.

Modern Cholera in the Americas: An Opportunistic Societal Infection

PubMed Central

Lee, Patrick T.

2013-01-01

In the Americas, the only two cholera epidemics of the past century have occurred in the past 25 years. Lessons from the 1991 Peruvian cholera epidemic can help to focus and refine the response to the current Haitian epidemic. After three years of acute epidemic response, we have an opportunity to refocus on the chronic conditions that make societies vulnerable to cholera. More importantly, even as international attention wanes in the aftermath of the earthquake and acute epidemic, we are faced with a need for continued and coordinated investment in improving Haiti’s structural defenses against cholera, in particular access to improved water and sanitation. PMID:24028256

Transmission dynamics of cholera: Mathematical modeling and control strategies

NASA Astrophysics Data System (ADS)

Sun, Gui-Quan; Xie, Jun-Hui; Huang, Sheng-He; Jin, Zhen; Li, Ming-Tao; Liu, Liqun

2017-04-01

Cholera, as an endemic disease around the world, has generated great threat to human society and caused enormous morbidity and mortality with weak surveillance system. In this paper, we propose a mathematical model to describe the transmission of Cholera. Moreover, basic reproduction number and the global dynamics of the dynamical model are obtained. Then we apply our model to characterize the transmission process of Cholera in China. It was found that, in order to avoid its outbreak in China, it may be better to increase immunization coverage rate and make effort to improve environmental management especially for drinking water. Our results may provide some new insights for elimination of Cholera.

Controlling cholera in the Ouest Department of Haiti using oral vaccines.

PubMed

Kirpich, Alexander; Weppelmann, Thomas A; Yang, Yang; Morris, John Glenn; Longini, Ira M

2017-04-01

Following the 2010 cholera outbreak in Haiti, a plan was initiated to provide massive improvements to the sanitation and drinking water infrastructure in order to eliminate cholera from the island of Hispaniola by 2023. Six years and a half billion dollars later, there is little evidence that any substantial improvements have been implemented; with increasing evidence that cholera has become endemic. Thus, it is time to explore strategies to control cholera in Haiti using oral cholera vaccines (OCVs). The potential effects of mass administration of OCVs on cholera transmission were assessed using dynamic compartment models fit to cholera incidence data from the Ouest Department of Haiti. The results indicated that interventions using an OCV that was 60% effective could have eliminated cholera transmission by August 2012 if started five weeks after the initial outbreak. A range of analyses on the ability of OCV interventions started January 1, 2017 to eliminate cholera transmission by 2023 were performed by considering different combinations of vaccine efficacies, vaccine administration rates, and durations of protective immunity. With an average of 50 weeks for the waiting time to vaccination and an average duration of three years for the vaccine-induced immunity, all campaigns that used an OCV with a vaccine efficacy of at least 60% successfully eliminated cholera transmission by 2023. The results of this study suggest that even with a relatively wide range of vaccine efficacies, administration rates, and durations of protective immunity, future epidemics could be controlled at a relatively low cost using mass administration of OCVs in Haiti.

Cholera: possible infection from aircraft effluent.

PubMed Central

Rondle, C. J.; Ramesh, B.; Krahn, J. B.; Sherriff, R.

1978-01-01

This paper presents the hypothesis that some cases of cholera might be due to effluent discharge from aircraft. The theoretical case is borne out by inspection of data on the physical conditions pertaining between high altitudes and ground level. A study of the distribution of isolated outbreaks and single cases of disease and their relation to major airline routes showed a reasonable correspondence. Sporadic outbreaks of cholera in Europe between 1970 and 1975 were found to lie within the flight paths of regular airline services from Calcutta, where cholera is endemic, to the Northern Hemisphere. Laboratory studies on the stability of Vibrio cholerae to conditions likely to be encountered in droplets falling from high altitude to the ground suggested that significant numbers of organisms might survive. It should be noted that in this study no account was taken of the effect of ultra-violet light on viability and it is known that at high altitides the ultraviolet light component of solar radiation is much higher than at ground level. Results of experiments where small numbers of organisms were inoculated into relatively poor media showed that rapid growth ensued and that sufficient organisms were produced to give an infective dose of Vibrio cholerae in 1-10 ml/fluid. It could be concluded that human infection could easily occur by ingestion of fluids such as milk or soup which had some time earlier received a fortuitous but slight contamination from the air. Investigation of one disinfectant (chloramine T) showed that it reacted rapidly and in a complex manner with peptone. One effect of this reaction was the elimination of bactericidal activity and it seems likely that, as at present employed, chloramine T is of doubtful value in aeroplane hygiene. One important conclusion that arises from this work is that if cholera can be spread, even only occasionally, by effluent from aircraft then close investigation should be made of the possibility of other bacteria and

Evidence of a Dominant Lineage of Vibrio cholerae-Specific Lytic Bacteriophages Shed by Cholera Patients over a 10-Year Period in Dhaka, Bangladesh

PubMed Central

Seed, Kimberley D.; Bodi, Kip L.; Kropinski, Andrew M.; Ackermann, Hans-Wolfgang; Calderwood, Stephen B.; Qadri, Firdausi; Camilli, Andrew

2011-01-01

Lytic bacteriophages are hypothesized to contribute to the seasonality and duration of cholera epidemics in Bangladesh. However, the bacteriophages contributing to this phenomenon have yet to be characterized at a molecular genetic level. In this study, we isolated and sequenced the genomes of 15 bacteriophages from stool samples from cholera patients spanning a 10-year surveillance period in Dhaka, Bangladesh. Our results indicate that a single novel bacteriophage type, designated ICP1 (for the International Centre for Diarrhoeal Disease Research, Bangladesh cholera phage 1) is present in all stool samples from cholera patients, while two other bacteriophage types, one novel (ICP2) and one T7-like (ICP3), are transient. ICP1 is a member of the Myoviridae family and has a 126-kilobase genome comprising 230 open reading frames. Comparative sequence analysis of ICP1 and related isolates from this time period indicates a high level of genetic conservation. The ubiquitous presence of ICP1 in cholera patients and the finding that the O1 antigen of lipopolysaccharide (LPS) serves as the ICP1 receptor suggest that ICP1 is extremely well adapted to predation of human-pathogenic V. cholerae O1. PMID:21304168

Cholera toxin expression by El Tor Vibrio cholerae in shallow culture growth conditions.

PubMed

Cobaxin, Mayra; Martínez, Haydee; Ayala, Guadalupe; Holmgren, Jan; Sjöling, Asa; Sánchez, Joaquín

2014-01-01

Vibrio cholerae O1 classical, El Tor and O139 are the primary biotypes that cause epidemic cholera, and they also express cholera toxin (CT). Although classical V. cholerae produces CT in various settings, the El Tor and O139 strains require specific growth conditions for CT induction, such as the so-called AKI conditions, which consist of growth in static conditions followed by growth under aerobic shaking conditions. However, our group has demonstrated that CT production may also take place in shallow static cultures. How these type of cultures induce CT production has been unclear, but we now report that in shallow culture growth conditions, there is virtual depletion of dissolved oxygen after 2.5 h of growth. Concurrently, during the first three to 4 h, endogenous CO2 accumulates in the media and the pH decreases. These findings may explain CT expression at the molecular level because CT production relies on a regulatory cascade, in which the key regulator AphB may be activated by anaerobiosis and by low pH. AphB activation stimulates TcpP synthesis, which induces ToxT production, and ToxT directly stimulates ctxAB expression, which encodes CT. Importantly, ToxT activity is enhanced by bicarbonate. Therefore, we suggest that in shallow cultures, AphB is activated by initial decreases in oxygen and pH, and subsequently, ToxT is activated by intracellular bicarbonate that has been generated from endogenous CO2. This working model would explain CT production in shallow cultures and, possibly, also in other growth conditions. Copyright © 2013 Elsevier Ltd. All rights reserved.

[Design and implementation of Geographical Information System on prevention and control of cholera].

PubMed

Li, Xiu-jun; Fang, Li-qun; Wang, Duo-chun; Wang, Lu-xi; Li, Ya-pin; Li, Yan-li; Yang, Hong; Kan, Biao; Cao, Wu-chun

2012-04-01

To build the Geographical Information System (GIS) database for prevention and control of cholera programs as well as using management analysis and function demonstration to show the spatial attribute of cholera. Data from case reporting system regarding diarrhoea, vibrio cholerae, serotypes of vibrio cholerae at the surveillance spots and seafoods, as well as surveillance data on ambient environment and climate were collected. All the data were imported to system database to show the incidence of vibrio cholerae in different provinces, regions and counties to support the spatial analysis through the spatial analysis of GIS. The epidemic trends of cholera, seasonal characteristics of the cholera and the variation of the vibrio cholerae with times were better understood. Information on hotspots, regions and time of epidemics was collected, and helpful in providing risk prediction on the incidence of vibrio cholerae. The exploitation of the software can predict and simulate the spatio-temporal risks, so as to provide guidance for the prevention and control of the disease.

Genome-Wide Study of the Defective Sucrose Fermenter Strain of Vibrio cholerae from the Latin American Cholera Epidemic

PubMed Central

Garza, Daniel Rios; Thompson, Cristiane C.; Loureiro, Edvaldo Carlos Brito; Dutilh, Bas E.; Inada, Davi Toshio; Junior, Edivaldo Costa Sousa; Cardoso, Jedson Ferreira; Nunes, Márcio Roberto T.; de Lima, Clayton Pereira Silva; Silvestre, Rodrigo Vellasco Duarte; Nunes, Keley Nascimento Barbosa; Santos, Elisabeth C. O.; Edwards, Robert A.; Vicente, Ana Carolina P.; de Sá Morais, Lena Lillian Canto

2012-01-01

The 7th cholera pandemic reached Latin America in 1991, spreading from Peru to virtually all Latin American countries. During the late epidemic period, a strain that failed to ferment sucrose dominated cholera outbreaks in the Northern Brazilian Amazon region. In order to understand the genomic characteristics and the determinants of this altered sucrose fermenting phenotype, the genome of the strain IEC224 was sequenced. This paper reports a broad genomic study of this strain, showing its correlation with the major epidemic lineage. The potentially mobile genomic regions are shown to possess GC content deviation, and harbor the main V. cholera virulence genes. A novel bioinformatic approach was applied in order to identify the putative functions of hypothetical proteins, and was compared with the automatic annotation by RAST. The genome of a large bacteriophage was found to be integrated to the IEC224's alanine aminopeptidase gene. The presence of this phage is shown to be a common characteristic of the El Tor strains from the Latin American epidemic, as well as its putative ancestor from Angola. The defective sucrose fermenting phenotype is shown to be due to a single nucleotide insertion in the V. cholerae sucrose-specific transportation gene. This frame-shift mutation truncated a membrane protein, altering its structural pore-like conformation. Further, the identification of a common bacteriophage reinforces both the monophyletic and African-Origin hypotheses for the main causative agent of the 1991 Latin America cholera epidemics. PMID:22662140

Prevalence of Vibrio cholerae with heat-stable enterotoxin (NAG-ST) and cholera toxin genes; restriction fragment length polymorphisms of NAG-ST genes among V. cholerae O serogroups from a major shrimp production area in Thailand.

PubMed

Dalsgaard, A; Serichantalergs, O; Shimada, T; Sethabutr, O; Echeverria, P

1995-09-01

A total of 148 Vibrio cholerae isolates from a major shrimp production area in Southern Thailand were examined by colony hybridisation for genes encoding heat-stable enterotoxin (NAG-ST) and cholera toxin (CT). Only non-O1 V. cholerae strains were found to harbour NAG-ST (14 of 146) whereas no strains hybridised with the CT probe. NAG-ST-positive V. cholerae non-O1 strains were isolated from shrimp farms situated close to urban areas. Five different O serogroups were found among NAG-ST positive non-O1 strains. Southern blot and restriction endonuclease analysis of NAG-ST-positive strains revealed a high degree of genetic divergence. A total of seven classes of enterotoxin gene patterns were found with HindIII and EcoRI restriction endonucleases. Enterotoxin gene patterns correlated with O-antigen expression in 84% of isolates tested. In combination with other molecular techniques Southern blot analysis with an NAG-ST oligonucleotide probe could be useful for studying the molecular epidemiology of V. cholerae non-O1 strains.

Non-01 Vibrio cholerae infections in Cancun, Mexico.

PubMed

Finch, M J; Valdespino, J L; Wells, J G; Perez-Perez, G; Arjona, F; Sepulveda, A; Bessudo, D; Blake, P A

1987-03-01

To determine the role of Vibrio cholerae as a cause of diarrheal illness in Cancun, Mexico, an investigation was conducted in July and August 1983. Although toxigenic V. cholerae 01 were not found, non-01 V. cholerae were isolated from 22 (16%) of 134 stools from persons with diarrheal illness and none of 22 stools from well persons; 58 (92%) of 63 sewage samples; 12 (86%) of 14 untreated well water samples; a home storage tank for treated water; and 5 (21%) of 24 samples of raw seafood. None of the V. cholerae isolates from patients were toxigenic. The illness occurred mainly in small children, and were characterized principally by diarrhea and abdominal pain. No patient was seriously ill, and all recovered without sequelae. Seven different serotypes of non-01 V. cholerae were isolated from the stool specimens, and Smith serotype 12 accounted for 10 (46%) of the 22 isolates. A matched-pair case-control study found that cases were more likely than controls to have eaten home prepared gelatin (P = 0.03, OR = 5/0) and seafood (P = 0.06, OR = 4/0).

Zinc oxide nanoparticles provide anti-cholera activity by disrupting the interaction of cholera toxin with the human GM1 receptor.

PubMed

Sarwar, Shamila; Ali, Asif; Pal, Mahadeb; Chakrabarti, Pinak

2017-11-03

Vibrio cholerae causes cholera and is the leading cause of diarrhea in developing countries, highlighting the need for the development of new treatment strategies to combat this disease agent. While exploring the possibility of using zinc oxide (ZnO) nanoparticles (NPs) in cholera treatment, we previously found that ZnO NPs reduce fluid accumulation in mouse ileum induced by the cholera toxin (CT) protein. To uncover the mechanism of action of ZnO NPs on CT activity, here we used classical (O395) and El Tor (C6706) V. cholerae biotypes in growth and biochemical assays. We found that a ZnO NP concentration of 10 μg/ml did not affect the growth rates of these two strains, nor did we observe that ZnO NPs reduce the expression levels of CT mRNA and protein. It was observed that ZnO NPs form a complex with CT, appear to disrupt the CT secondary structure, and block its interaction with the GM1 ganglioside receptor in the outer leaflet of the plasma membrane in intestinal (HT-29) cells and thereby reduce CT uptake into the cells. In the range of 2.5-10 μg/ml, ZnO NPs exhibited no cytotoxicity on kidney (HEK293) and HT-29 cells. We conclude that ZnO NPs prevent the first step in the translocation of cholera toxin into intestinal epithelial cells without exerting measurable toxic effects on HEK293 and HT-29 cells. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Seasonality of cholera from 1974 to 2005: a review of global patterns

PubMed Central

Emch, Michael; Feldacker, Caryl; Islam, M Sirajul; Ali, Mohammad

2008-01-01

Background The seasonality of cholera is described in various study areas throughout the world. However, no study examines how temporal cycles of the disease vary around the world or reviews its hypothesized causes. This paper reviews the literature on the seasonality of cholera and describes its temporal cycles by compiling and analyzing 32 years of global cholera data. This paper also provides a detailed literature review on regional patterns and environmental and climatic drivers of cholera patterns. Data, Methods, and Results Cholera data are compiled from 1974 to 2005 from the World Health Organization Weekly Epidemiological Reports, a database that includes all reported cholera cases in 140 countries. The data are analyzed to measure whether season, latitude, and their interaction are significantly associated with the country-level number of outbreaks in each of the 12 preceding months using separate negative binomial regression models for northern, southern, and combined hemispheres. Likelihood ratios tests are used to determine the model of best fit. The results suggest that cholera outbreaks demonstrate seasonal patterns in higher absolute latitudes, but closer to the equator, cholera outbreaks do not follow a clear seasonal pattern. Conclusion The findings suggest that environmental and climatic factors partially control the temporal variability of cholera. These results also indirectly contribute to the growing debate about the effects of climate change and global warming. As climate change threatens to increase global temperature, resulting rises in sea levels and temperatures may influence the temporal fluctuations of cholera, potentially increasing the frequency and duration of cholera outbreaks. PMID:18570659

Emergence and spread of tetracycline resistant Vibrio cholerae O1 El Tor variant during 2010 cholera epidemic in the tribal areas of Odisha, India.

PubMed

Kar, Santanu Kumar; Pal, Bibhuti Bhusan; Khuntia, Hemanta Kumar; Achary, K Gopinath; Khuntia, Chinmaye Priyadarshini

2015-04-01

The epidemics of cholera were reported in the Kashipur, K.singhpur, B cuttack blocks of Rayagada district and Mohana block of Gajapati district of Odisha during 2010. The present study was carried out to isolate the bacterial pathogen, its drug sensitivity pattern and to describe the spread of the disease in those areas. A total of 68 rectal swabs collected from patients with severe diarrhea, admitted to different health centers and diarrhea affected villages were bacteriologically analyzed. Similarly 22 water samples collected from different villages from nala, chua, etc were tested for the presence of V cholerae. Out of 68 rectal swabs tested 35 (51.5%) were V cholerae O1 Ogawa and 14(20.6%) were E coli; which might be commensals. All water samples were negative for V cholerae. The V cholerae strains were sensitive to gentamicin, norfloxacin, ciprofloxacin, azithromycin and ofloxacin; but were resistant to ampicillin, tetracycline, nalidixic acid, furazolidone, streptomycin, erythromycin, co-trimoxazole, neomycin and chloramphenicol. All V cholerae strains were 100% resistant to tetracycline and they were El Tor variants harboring ctxB gene of classical strain. The present study indicated the emergence and spread of tetracycline resistant V cholerae O1 El Tor variant in the tribal areas which needs close monitoring. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

An outbreak of cholera from food served on an international aircraft.

PubMed

Eberhart-Phillips, J; Besser, R E; Tormey, M P; Koo, D; Feikin, D; Araneta, M R; Wells, J; Kilman, L; Rutherford, G W; Griffin, P M; Baron, R; Mascola, L

1996-02-01

In February 1992, an outbreak of cholera occurred among persons who had flown on a commercial airline flight from South America to Los Angeles. This study was conducted to determine the magnitude and the cause of the outbreak. Passengers were interviewed and laboratory specimens were collected to determine the magnitude of the outbreak. A case-control study was performed to determine the vehicle of infection. Seventy-five of the 336 passengers in the United States had cholera; 10 were hospitalized and one died. Cold seafood salad, served between Lima, Peru and Los Angeles, California was the vehicle of infection (odds ratio, 11.6; 95% confidence interval, 3.3-44.5). This was the largest airline-associated outbreak of cholera ever reported and demonstrates the potential for airline-associated spread of cholera from epidemic areas to other parts of the world. Physicians should obtain a travel history and consider cholera in patients with diarrhoea who have travelled from cholera-affected countries. This outbreak also highlights the risks associated with eating cold foods prepared in cholera-affected countries.

An outbreak of cholera from food served on an international aircraft.

PubMed Central

Eberhart-Phillips, J.; Besser, R. E.; Tormey, M. P.; Koo, D.; Feikin, D.; Araneta, M. R.; Wells, J.; Kilman, L.; Rutherford, G. W.; Griffin, P. M.; Baron, R.; Mascola, L.

1996-01-01

In February 1992, an outbreak of cholera occurred among persons who had flown on a commercial airline flight from South America to Los Angeles. This study was conducted to determine the magnitude and the cause of the outbreak. Passengers were interviewed and laboratory specimens were collected to determine the magnitude of the outbreak. A case-control study was performed to determine the vehicle of infection. Seventy-five of the 336 passengers in the United States had cholera; 10 were hospitalized and one died. Cold seafood salad, served between Lima, Peru and Los Angeles, California was the vehicle of infection (odds ratio, 11.6; 95% confidence interval, 3.3-44.5). This was the largest airline-associated outbreak of cholera ever reported and demonstrates the potential for airline-associated spread of cholera from epidemic areas to other parts of the world. Physicians should obtain a travel history and consider cholera in patients with diarrhoea who have travelled from cholera-affected countries. This outbreak also highlights the risks associated with eating cold foods prepared in cholera-affected countries. PMID:8626007

A simple and convenient microtiter plate assay for the detection of bactericidal antibodies to Vibrio cholerae O1 and Vibrio cholerae O139.

PubMed

Boutonnier, Alain; Dassy, Bruno; Duménil, Rémy; Guénolé, Alain; Ratsitorahina, Maherisoa; Migliani, René; Fournier, Jean-Michel

2003-12-01

It is believed that the correlate of protection for cholera can be determined by the serum vibriocidal assay. The currently available vibriocidal assays, based on the conventional agar plating technique, are labor intensive. We developed a simple and convenient microtiter plate assay for the detection of vibriocidal antibodies that is equally as efficient for Vibrio cholerae O1 and for V. cholerae O139. The addition of succinate and neotetrazolium made it possible to measure the growth of surviving bacterial target cells by monitoring a color change. We evaluated assay parameters (target strains, growth of target cells, complement source and concentration) that may affect the reproducibility of the method for V. cholerae O139. The results obtained with the microtiter plate assay were uniformly similar to those obtained with the conventional agar plating assay, when testing both the Inaba and Ogawa serotypes of V. cholerae O1. The microtiter plate assay was also convenient for measuring the activity of animal sera and mouse monoclonal antibodies.

Health impairments arising from drinking water resources contaminated with Vibrio cholerae.

PubMed

Ramamurthy, T; Chakraborty, S; Nair, G B; Bhattacharya, S K

2000-01-01

The endemic and seasonal nature of cholera depends upon the survival of toxigenic Vibrio cholerae in various niches of the aquatic environment. To understand the transmission and ecology of V. cholerae, it is necessary to know which component in the aquatic ecosystem can harbor it and thus contribute to the endemic presence. Toxigenic V. cholerae is now recognized as an autochthonous member of the microflora in many aquatic environments based on its protracted survival and proliferation without losing the virulence determinants. This article summarizes knowledge about the ecology, survival strategies and elimination techniques of V. cholerae from natural waters with special reference to drinking water.

Predictive modeling of cholera using GRACE and TRMM satellite data

NASA Astrophysics Data System (ADS)

Jutla, A.; Akanda, A. S. S.; Colwell, R. R.

2015-12-01

Cholera outbreaks can be classified in three forms- epidemic (sudden or seasonal outbreaks), endemic (recurrence and persistence of the disease for several consecutive years) and mixed-mode endemic (combination of certain epidemic and endemic conditions) with significant spatial and temporal heterogeneity. Endemic cholera is related to floods and droughts in regions where water and sanitation infrastructure are inadequate or insufficient. With more than a decade of terrestrial water storage (TWS) data obtained from Gravity Recovery and Climate Experiment (GRACE), understanding dynamics of river discharge is now feasible. We explored lead-lag relationships between TWS in the Ganges-Brahmaputra-Meghna (GBM) basin and endemic cholera in Bangladesh. Since bimodal seasonal peaks in cholera in Bangladesh occur during the spring and autumn season, two separate models, between TWS and disease time series (2002 to 2010) were developed. TWS, hence water availability, showed an asymmetrical, strong association with spring (τ=-0.53; p<0.001) and autumn (τ=0.45; p<0.001) cholera prevalence up to five to six months in advance. One unit (cm of water) decrease in water availability in the basin increased odds of above normal cholera by 24% [confidence interval (CI) 20-31%; p<0.05] in the spring season, while an increase in regional water by one unit, through floods, increased odds of above average cholera in the autumn by 29% [CI:22-33%; p<0.05]. Epidemic cholera is related with warm temperatures and heavy rainfall. Using TRMM data for several locations in Asia and Africa, probability of cholera increases 18% [CI:15-23%; p<0.05] after heavy precipitation resulted in a societal conditions where access to safe water and sanitation was disrupted. Results from mechanistic modeling framework using systems approach that include satellite based hydroclimatic information with tradition disease transmission models will also be presented.

[Phenotypic and genotypic characterization of Vibrio cholerae O1].

PubMed

Giono-Cerezo, S; Rodríguez Angeles, M G; Gutiérrez-Cogco, L; Valdespino-Gómez, J L

1994-01-01

We made 52180 tests for isolation and identification of toxigenic V. cholerae O1 from rectal swabs and reference strains. We isolated 17.6% V. cholerae O1 strains in 1991, 43.5% in 1992 and 38.9% in 1993. The main serovar in 1991 was Inaba, whereas in 1993 a similar percentage was serovar Ogawa. The phenotype of V. cholerae strains was determined by hemolysis test, Voges-Proskauer test, polymyxin B resistance and phages 4 and 5 resistance. All of the mexican strains were El Tor. There were 2.9-0.75% hemolytic strains from 1991 to 1993, but they were negative when the test was made in tube with human erythrocytes. The resistotypes were performed in 24526 selected strains by Kirby-Bauer method and MIC tests. All of the strains were sensitive, except more than 100 strains isolated in Veracruz that were resistant to tetracycline and doxycycline. Detection of cholera toxin was made by ELISA and on culture of Vero and CHO cells. All the V. cholerae O1 strains were toxigenic. The genotype was determined by PCR and ribotyping. The PCR amplified one 564 pb fragment on V. cholerae O1. The ribotypes of mexican strains were 5 and 6a.

Osmostress induces autophosphorylation of Hog1 via a C-terminal regulatory region that is conserved in p38α.

PubMed

Maayan, Inbal; Beenstock, Jonah; Marbach, Irit; Tabachnick, Shira; Livnah, Oded; Engelberg, David

2012-01-01

Many protein kinases require phosphorylation at their activation loop for induction of catalysis. Mitogen-activated protein kinases (MAPKs) are activated by a unique mode of phosphorylation, on neighboring Tyrosine and Threonine residues. Whereas many kinases obtain their activation via autophosphorylation, MAPKs are usually phosphorylated by specific, dedicated, MAPK kinases (MAP2Ks). Here we show however, that the yeast MAPK Hog1, known to be activated by the MAP2K Pbs2, is activated in pbs2Δ cells via an autophosphorylation activity that is induced by osmotic pressure. We mapped a novel domain at the Hog1 C-terminal region that inhibits this activity. Removal of this domain provides a Hog1 protein that is partially independent of MAP2K, namely, partially rescues osmostress sensitivity of pbs2Δ cells. We further mapped a short domain (7 amino acid residues long) that is critical for induction of autophosphorylation. Its removal abolishes autophosphorylation, but maintains Pbs2-mediated phosphorylation. This 7 amino acids stretch is conserved in the human p38α. Similar to the case of Hog1, it's removal from p38α abolishes p38α's autophosphorylation capability, but maintains, although reduces, its activation by MKK6. This study joins a few recent reports to suggest that, like many protein kinases, MAPKs are also regulated via induced autoactivation.

Osmostress Induces Autophosphorylation of Hog1 via a C-Terminal Regulatory Region That Is Conserved in p38α

PubMed Central

Maayan, Inbal; Beenstock, Jonah; Marbach, Irit; Tabachnick, Shira; Livnah, Oded; Engelberg, David

2012-01-01

Many protein kinases require phosphorylation at their activation loop for induction of catalysis. Mitogen-activated protein kinases (MAPKs) are activated by a unique mode of phosphorylation, on neighboring Tyrosine and Threonine residues. Whereas many kinases obtain their activation via autophosphorylation, MAPKs are usually phosphorylated by specific, dedicated, MAPK kinases (MAP2Ks). Here we show however, that the yeast MAPK Hog1, known to be activated by the MAP2K Pbs2, is activated in pbs2Δ cells via an autophosphorylation activity that is induced by osmotic pressure. We mapped a novel domain at the Hog1 C-terminal region that inhibits this activity. Removal of this domain provides a Hog1 protein that is partially independent of MAP2K, namely, partially rescues osmostress sensitivity of pbs2Δ cells. We further mapped a short domain (7 amino acid residues long) that is critical for induction of autophosphorylation. Its removal abolishes autophosphorylation, but maintains Pbs2-mediated phosphorylation. This 7 amino acids stretch is conserved in the human p38α. Similar to the case of Hog1, it’s removal from p38α abolishes p38α’s autophosphorylation capability, but maintains, although reduces, its activation by MKK6. This study joins a few recent reports to suggest that, like many protein kinases, MAPKs are also regulated via induced autoactivation. PMID:22984552

[The immunology of cholera and the molecular biology of cholera toxin. Recent progress and future perspectives].

PubMed

Carrada-Bravo, T

1994-01-01

Vibrio cholerae has recently called the attention of researchers due to its strong immunogenicity and also because it serves as coadjunct immunomodulator of the immune response of the intestinal mucosae for the mixed added antigens as well as for those covalently linked to the toxin. The immunopathogeny of cholera is a complex phenomenon. This article presents the preliminary results of experiments conducted with laboratory rats in order to find the IgA intestinal response of rodents and humans.

Recommendations of the Advisory Committee on Immunization Practices for Use of Cholera Vaccine.

PubMed

Wong, Karen K; Burdette, Erin; Mahon, Barbara E; Mintz, Eric D; Ryan, Edward T; Reingold, Arthur L

2017-05-12

Cholera, caused by infection with toxigenic Vibrio cholerae bacteria of serogroup O1 (>99% of global cases) or O139, is characterized by watery diarrhea that can be severe and rapidly fatal without prompt rehydration. Cholera is endemic in approximately 60 countries and causes epidemics as well. Globally, cholera results in an estimated 2.9 million cases of disease and 95,000 deaths annually (1). Cholera is rare in the United States, and most U.S. cases occur among travelers to countries where cholera is endemic or epidemic. Forty-two U.S. cases were reported in 2011 after a cholera epidemic began in Haiti (2); however, <25 cases per year have been reported in the United States since 2012.

[A prognostic model of a cholera epidemic].

PubMed

Boev, B V; Bondarenko, V M; Prokop'eva, N V; San Román, R T; Raygoza-Anaya, M; García de Alba, R

1994-01-01

A new model for the prognostication of cholera epidemic on the territory of a large city is proposed. This model reflects the characteristic feature of contacting infection by sensitive individuals due to the preservation of Vibrio cholerae in their water habitat. The mathematical model of the epidemic quantitatively reflects the processes of the spread of infection by kinetic equations describing the interaction of the streams of infected persons, the causative agents and susceptible persons. The functions and parameters of the model are linked with the distribution of individuals according to the duration of the incubation period and infectious process, as well as the period of asymptomatic carrier state. The computer realization of the model by means of IBM PC/AT made it possible to study the cholera epidemic which took place in Mexico in 1833. The verified model of the cholera epidemic was used for the prognostication of the possible spread of this infection in Guadalajara, taking into account changes in the epidemiological situation and the size of the population, as well as improvements in sanitary and hygienic conditions, in the city.

El Niño, Rainfall, and the Shifting Geography of Cholera in Africa

NASA Astrophysics Data System (ADS)

Moore, S.; Azman, A. S.; Zaitchik, B. F.; McKay, H.; Lessler, J.

2017-12-01

The El Niño Southern Oscillation (ENSO) and other climate patterns can have profound impacts on the occurrence of infectious diseases. Because of the key role of water supplies in cholera transmission, a relationship between El Niño events and cholera incidence is highly plausible, and previous research has shown a link between El Niño patterns and cholera in Bangladesh. However, there is little systematic evidence for this link in Africa where many cholera cases and deaths are reported. To understand how ENSO affects the geographic distribution of cholera incidence in Africa, we used a hierarchical Bayesian approach to integrate over 17,000 annual observations of cholera incidence from 2000-2014 in over 3,000 unique locations of varying spatial extent, ranging from entire countries to neighborhoods. The resulting maps reflect modeled cholera incidence at a fine spatial resolution using reported counts of cholera cases, key explanatory variables, and a spatially-dependent covariance term. We then examined the potential mechanistic association between ENSO-related changes in cholera incidence and several environmental variables including rainfall. El Niño profoundly changed the annual geographic distribution of cholera in Africa from 2000-2014, shifting the burden to continental East Africa, where almost 50,000 additional cases occur during El Niño years. Cholera incidence during El Niño years was higher in regions of East Africa with increased rainfall, but incidence was also higher in some areas with decreased rainfall suggesting a complex relationship between rainfall and cholera incidence. Here we show clear evidence for a shift in the distribution of cholera incidence throughout Africa in El Niño and non-El Niño years, likely mediated by El Niño's impact on local climatic factors. Knowledge of this relationship between cholera and climate patterns coupled with El Niño forecasting could be used to notify countries in Africa when they are likely to see

Geospatial and temporal patterns of annual cholera outbreaks in Matlab, Bangladesh

NASA Astrophysics Data System (ADS)

Majumder, M. S.; de Klerk, K.; Meyers, D.

2012-12-01

Cholera is a waterborne diarrheal disease endemic to Bangladesh, resulting in 1 million diagnoses annually. Such disease burden results in incalculable lost wages and treatment expenses, taken from the pockets of an already impoverished society. Two seasonally correlated outbreaks of cholera occur in Bangladesh every year. In the spring and early summer, the Bay of Bengal - which serves as a natural reservoir for the cholera bacteria - flows inland, causing the first outbreak amongst coastal communities. Waste containing the cholera bacteria enters the sewage system and remains untreated due to poor water and sanitation infrastructure. Therefore, during the following monsoon season, flooding of cholera-contaminated sewage into drinking water sources results in a second outbreak. Though considered common knowledge among local populations, this geographic and temporal progression has not been empirically verified in the current literature. The aim of our ongoing study is to systematically analyze the seasonal trajectory of endemic cholera in Bangladesh. This paper discusses the results obtained from a comprehensive survey of available cholera data from the International Centre of Diarrheal Disease Research, Bangladesh (ICDDR,B) in Matlab, Bangladesh. Matlab thana is a near-coastal community that consists of 142 villages. Monsoon season takes place from June through October. Due to its proximity to the Meghna River, which opens into the Bay of Bengal, the area experiences significant flooding during these months. Using 10 years of geographically referenced cholera data, cases were plotted in time and space. Preliminary patterns suggest that villages closer to the Meghna River experience the majority of the area's cholera outbreaks and that case count is highest in late spring and late fall. April/May and November/December represent 25% and 23% of total annual case counts respectively. Moreover, villages further from the coastline demonstrate 57% higher relative

Safety of the recombinant cholera toxin B subunit, killed whole-cell (rBS-WC) oral cholera vaccine in pregnancy.

PubMed

Hashim, Ramadhan; Khatib, Ahmed M; Enwere, Godwin; Park, Jin Kyung; Reyburn, Rita; Ali, Mohammad; Chang, Na Yoon; Kim, Deok Ryun; Ley, Benedikt; Thriemer, Kamala; Lopez, Anna Lena; Clemens, John D; Deen, Jacqueline L; Shin, Sunheang; Schaetti, Christian; Hutubessy, Raymond; Aguado, Maria Teresa; Kieny, Marie Paule; Sack, David; Obaro, Stephen; Shaame, Attiye J; Ali, Said M; Saleh, Abdul A; von Seidlein, Lorenz; Jiddawi, Mohamed S

2012-01-01

Mass vaccinations are a main strategy in the deployment of oral cholera vaccines. Campaigns avoid giving vaccine to pregnant women because of the absence of safety data of the killed whole-cell oral cholera (rBS-WC) vaccine. Balancing this concern is the known higher risk of cholera and of complications of pregnancy should cholera occur in these women, as well as the lack of expected adverse events from a killed oral bacterial vaccine. From January to February 2009, a mass rBS-WC vaccination campaign of persons over two years of age was conducted in an urban and a rural area (population 51,151) in Zanzibar. Pregnant women were advised not to participate in the campaign. More than nine months after the last dose of the vaccine was administered, we visited all women between 15 and 50 years of age living in the study area. The outcome of pregnancies that were inadvertently exposed to at least one oral cholera vaccine dose and those that were not exposed was evaluated. 13,736 (94%) of the target women in the study site were interviewed. 1,151 (79%) of the 1,453 deliveries in 2009 occurred during the period when foetal exposure to the vaccine could have occurred. 955 (83%) out of these 1,151 mothers had not been vaccinated; the remaining 196 (17%) mothers had received at least one dose of the oral cholera vaccine. There were no statistically significant differences in the odds ratios for birth outcomes among the exposed and unexposed pregnancies. We found no statistically significant evidence of a harmful effect of gestational exposure to the rBS-WC vaccine. These findings, along with the absence of a rational basis for expecting a risk from this killed oral bacterial vaccine, are reassuring but the study had insufficient power to detect infrequent events. ClinicalTrials.gov NCT00709410.

Increased severity in patients presenting to hospital with diarrhea in Dhaka, Bangladesh Since emergence of the hybrid strain of Vibrio cholerae O1 is not unique to cholera patients

PubMed Central

Chowdhury, Fahima; Kuchta, Alison; Khan, Ashraful Islam; Faruque, ASG; Calderwood, Stephen B.; Ryan, Edward T.; Qadri, Firdausi

2015-01-01

In 2001, a hybrid strain of Vibrio cholerae O1 El Tor that expresses a classical cholera toxin (CT) emerged and this hybrid variant rapidly replaced the previous El Tor strain around the world. The global emergence of this variant coincided with anecdotal reports that cholera patients were presenting with more severe dehydration and disease in many locations. We compared severity of disease in cholera patients from before and after emergence of the hybrid strain at a diarrheal hospital in Dhaka, Bangladesh. We did indeed find that cholera patients presented with more severe dehydration and severe disease in the latter period; however, this was also true for “all non-cholera patients” as well. In addition, in sub-analyses of patients who presented with rotavirus and enterotoxigenic E. coli (ETEC), we found similar results. Comparing the two periods for differences in patient characteristics, nutritional status, vaccination status and income, we were unable to detect a plausible cause for patients presenting with more severe disease in the latter period. Because we observed a shift in severity for both cholera and non-cholera, our results indicate that the altered El Tor strain cannot fully explain the differences in cholera severity before and after 2001 PMID:26409202

Human Mobility Patterns and Cholera Epidemics: a Spatially Explicit Modeling Approach

NASA Astrophysics Data System (ADS)

Mari, L.; Bertuzzo, E.; Righetto, L.; Casagrandi, R.; Gatto, M.; Rodriguez-Iturbe, I.; Rinaldo, A.

2010-12-01

Cholera is an acute enteric disease caused by the ingestion of water or food contaminated by the bacterium Vibrio cholerae. Although most infected individuals do not develop severe symptoms, their stool may contain huge quantities of V.~cholerae cells. Therefore, while traveling or commuting, asymptomatic carriers can be responsible for the long-range dissemination of the disease. As a consequence, human mobility is an alternative and efficient driver for the spread of cholera, whose primary propagation pathway is hydrological transport through river networks. We present a multi-layer network model that accounts for the interplay between epidemiological dynamics, hydrological transport and long-distance dissemination of V.~cholerae due to human movement. In particular, building on top of state-of-the-art spatially explicit models for cholera spread through surface waters, we describe human movement and its effects on the propagation of the disease by means of a gravity-model approach borrowed from transportation theory. Gravity-like contact processes have been widely used in epidemiology, because they can satisfactorily depict human movement when data on actual mobility patterns are not available. We test our model against epidemiological data recorded during the cholera outbreak occurred in the KwaZulu-Natal province of South Africa during years 2000--2001. We show that human mobility does actually play an important role in the formation of the spatiotemporal patterns of cholera epidemics. In particular, long-range human movement may determine inter-catchment dissemination of V.~cholerae cells, thus in turn explaining the emergence of epidemic patterns that cannot be produced by hydrological transport alone. We also show that particular attention has to be devoted to study how heterogeneously distributed drinking water supplies and sanitation conditions may affect cholera transmission.

Acalculous cholecystitis and septicemia caused by non-O1 Vibrio cholerae: first reported case and review of biliary infections with Vibrio cholerae.

PubMed

West, B C; Silberman, R; Otterson, W N

1998-03-01

The first case of septicemic acute acalculous cholecystitis caused by non-O1 Vibrio cholerae is described in a healthy traveler, and biliary tract infections from V. cholerae are reviewed. Immediately after a vacation in Cancun, Mexico, a 55-year-old man developed acute cholecystitis. Blood and bile cultures grew non-O1 V. cholerae. At surgery, the gallbladder was acalculous, inflamed, distended, and nearly ruptured. Pathogenetic factors may have included diarrhea prophylaxis with bismuth subsalicylate, distension of the gallbladder from illness-induced fasting, and bacterial toxins in the gallbladder. The patient received i.v. cephapirin, followed by oral cephradine for a total of 10 days, and he made a quick and complete recovery. V. cholerae should be considered in the differential diagnosis of persons from endemic areas who present with cholecystitis or acute jaundice.

Epidemic waves of cholera in the last two decades in Mozambique.

PubMed

Langa, José Paulo; Sema, Cynthia; De Deus, Nilsa; Colombo, Mauro Maria; Taviani, Elisa

2015-07-04

Africa is increasingly affected by cholera. In Mozambique, cholera appeared in the early 1970s when the seventh pandemic entered Africa from the Indian subcontinent. In the following decades, several epidemics were registered in the country, the 1997-1999 epidemic being the most extended. Since then, Mozambique has been considered an endemic area for cholera, characterized by yearly outbreaks occurring with a seasonal pattern. At least three pandemic variants are thought to have originated in the Indian subcontinent and spread worldwide at different times. To understand the epidemiology of cholera in Mozambique, whether the disease re-emerges periodically or is imported by different routes of transmission, we investigated clinical V. cholerae O1 isolated during 1997-1999 and 2012-2014 epidemics. By detecting and characterizing seven genetic elements, the mobilome profile of each isolate was obtained. By comparing it to known seventh pandemic reference strains, it was possible to discern among different V. cholerae O1 variants active in the country. During 1997-1999, epidemic strains showed two different genetic profiles, both related to a pandemic clone that originated from India and was reported in other African countries in the 1990s. Isolates from 2012-2014 outbreaks showed a genetic background related to the pandemic strains currently active as the prevalent causative agent of cholera worldwide. Despite cholera being endemic in Mozambique, the epidemiology of the disease in the past 20 years has been strongly influenced by the cholera seventh pandemic waves that originated in the Indian subcontinent.

Effects of global climate on infectious disease: the cholera model.

PubMed

Lipp, Erin K; Huq, Anwar; Colwell, Rita R

2002-10-01

Recently, the role of the environment and climate in disease dynamics has become a subject of increasing interest to microbiologists, clinicians, epidemiologists, and ecologists. Much of the interest has been stimulated by the growing problems of antibiotic resistance among pathogens, emergence and/or reemergence of infectious diseases worldwide, the potential of bioterrorism, and the debate concerning climate change. Cholera, caused by Vibrio cholerae, lends itself to analyses of the role of climate in infectious disease, coupled to population dynamics of pathogenic microorganisms, for several reasons. First, the disease has a historical context linking it to specific seasons and biogeographical zones. In addition, the population dynamics of V. cholerae in the environment are strongly controlled by environmental factors, such as water temperature, salinity, and the presence of copepods, which are, in turn, controlled by larger-scale climate variability. In this review, the association between plankton and V. cholerae that has been documented over the last 20 years is discussed in support of the hypothesis that cholera shares properties of a vector-borne disease. In addition, a model for environmental transmission of cholera to humans in the context of climate variability is presented. The cholera model provides a template for future research on climate-sensitive diseases, allowing definition of critical parameters and offering a means of developing more sophisticated methods for prediction of disease outbreaks.

MOLECULAR CHARACTERIZATION OF VIBRIO CHOLERAE GENES FLGO AND FLGP

DTIC Science & Technology

2006-12-01

From - To) 25-01-2007 THESIS 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER MOLECULAR CHARACTERIZATION OF VIBRIO CHOLERAE GENES FLGO AND FLGP 5b. GRANT...CHARACTERIZATION OF VIBRIO CHOLERAE GENES FLGO AND FLGP by DAVID C. MORRIS, B.S. THESIS Presented to the Graduate Faculty of The University of Texas at San Antonio...U.S. Air Force for providing me the opportunity and means to complete the thesis. December 2006 v MOLECULAR CHARACTERIZATION OF VIBRIO CHOLERAE GENES

Genetic diversity of environmental Vibrio cholerae O1 strains isolated in Northern Vietnam.

PubMed

Takemura, Taichiro; Murase, Kazunori; Maruyama, Fumito; Tran, Thi Luong; Ota, Atsushi; Nakagawa, Ichiro; Nguyen, Dong Tu; Ngo, Tu Cuong; Nguyen, Thi Hang; Tokizawa, Asako; Morita, Masatomo; Ohnishi, Makoto; Nguyen, Binh Minh; Yamashiro, Tetsu

2017-10-01

Cholera epidemics have been recorded periodically in Vietnam during the seventh cholera pandemic. Since cholera is a water-borne disease, systematic monitoring of environmental waters for Vibrio cholerae presence is important for predicting and preventing cholera epidemics. We conducted monitoring, isolation, and genetic characterization of V. cholerae strains in Nam Dinh province of Northern Vietnam from Jul 2013 to Feb 2015. In this study, four V. cholerae O1 strains were detected and isolated from 110 analyzed water samples (3.6%); however, none of them carried the cholera toxin gene, ctxA, in their genomes. Whole genome sequencing and phylogenetic analysis revealed that the four O1 isolates were separated into two independent clusters, and one of them diverged from a common ancestor with pandemic strains. The analysis of pathogenicity islands (CTX prophage, VPI-I, VPI-II, VSP-I, and VSP-II) indicated that one strain (VNND_2014Jun_6SS) harbored an unknown prophage-like sequence with high homology to vibriophage KSF-1 phi and VCY phi, identified from Bangladesh and the USA, respectively, while the other three strains carried tcpA gene with a distinct sequence demonstrating a separate clonal lineage. These results suggest that the aquatic environment can harbor highly divergent V. cholera strains and serve as a reservoir for multiple V. cholerae virulence-associated genes which may be exchanged via mobile genetic elements. Therefore, continuous monitoring and genetic characterization of V. cholerae strains in the environment should contribute to the early detection of the sources of infection and prevention of cholera outbreaks as well as to understanding the natural ecology and evolution of V. cholerae. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Cyclo(valine-valine) inhibits Vibrio cholerae virulence gene expression.

PubMed

Vikram, Amit; Ante, Vanessa M; Bina, X Renee; Zhu, Qin; Liu, Xinyu; Bina, James E

2014-06-01

Vibrio cholerae has been shown to produce a cyclic dipeptide, cyclo(phenylalanine-proline) (cFP), that functions to repress virulence factor production. The objective of this study was to determine if heterologous cyclic dipeptides could repress V. cholerae virulence factor production. To that end, three synthetic cyclic dipeptides that differed in their side chains from cFP were assayed for virulence inhibitory activity in V. cholerae. The results revealed that cyclo(valine-valine) (cVV) inhibited virulence factor production by a ToxR-dependent process that resulted in the repression of the virulence regulator aphA. cVV-dependent repression of aphA was found to be independent of known aphA regulatory genes. The results demonstrated that V. cholerae was able to respond to exogenous cyclic dipeptides and implicated the hydrophobic amino acid side chains on both arms of the cyclo dipeptide scaffold as structural requirements for inhibitory activity. The results further suggest that cyclic dipeptides have potential as therapeutics for cholera treatment. © 2014 The Authors.

Oral cholera vaccine--for whom, when, and why?

PubMed

Topps, Maureen H

2006-01-01

The search for a safe, effective, well tolerated, low cost vaccine against the ancient cholera enemy has been ongoing since the 19th century and has been revitalized in the past two decades since the advent of recombinant technology. Large-scale field trials have readily demonstrated the tolerability and safety of oral cholera vaccine in various forms. Variable levels of protection have been shown and one challenge has been to demonstrate whether this is a cost effective treatment in differing environments including its use in endemic and epidemic areas as well as for travelers. A review of recent literature was undertaken to assess the effectiveness and uses of currently available oral cholera vaccine. While the evidence does not support the creation of formal guidelines, some clear recommendations can be made. There is undoubtedly the potential to reduce the burden of illness both in endemic and epidemic situations. For travelers, certain higher risk groups may benefit from protection against cholera. More significantly, the short term cross-protection afforded by whole cell, B subunit (WC BS) oral cholera vaccine formulations against enterotoxigenic E. coli, (ETEC), the commonest causative agent of traveler's diarrhoea, may prove to be the most important raison d'être.

Lessons learnt from 12 oral cholera vaccine campaigns in resource-poor settings.

PubMed

Hsiao, Amber; Desai, Sachin N; Mogasale, Vittal; Excler, Jean-Louis; Digilio, Laura

2017-04-01

Improving water and sanitation is the preferred choice for cholera control in the long-term. Nevertheless, vaccination is an available tool that has been shown to be a cost-effective option for cholera prevention in endemic countries or during outbreaks. In 2011 the first low-cost oral cholera vaccine for international use was given prequalification by the World Health Organization (WHO). To increase and prioritize use of the vaccine, WHO created a global stockpile in 2013 from which countries may request oral cholera vaccine for reactive campaigns. WHO has issued specific guidelines for applying for the vaccine, which was previously in short supply (despite prequalification for a second oral vaccine in 2015). The addition of a third WHO-prequalified oral cholera vaccine in 2016 is expected to increase the global stockpile considerably and alleviate supply issues. However, prioritization and best use of the vaccine (e.g. how, when and where to use) will remain challenges. We describe 12 past oral cholera vaccine campaigns, conducted in settings with varying burdens of cholera. These case studies illustrate three key challenges faced in the use of the oral cholera vaccines: regulatory hurdles, cold chain logistics and vaccine coverage and uptake. To pave the way for the introduction of current and future oral cholera vaccines, we discuss operational challenges and make recommendations for future research with respect to each of these challenges.

Molecular Epidemiology of Cholera Outbreaks during the Rainy Season in Mandalay, Myanmar.

PubMed

Roobthaisong, Amonrattana; Okada, Kazuhisa; Htun, Nilar; Aung, Wah Wah; Wongboot, Warawan; Kamjumphol, Watcharaporn; Han, Aye Aye; Yi, Yi; Hamada, Shigeyuki

2017-11-01

Cholera, caused by Vibrio cholerae , remains a global threat to public health. In Myanmar, the availability of published information on the occurrence of the disease is scarce. We report here that cholera incidence in Mandalay generally exhibited a single annual peak, with an annual average of 312 patients with severe dehydration over the past 5 years (since 2011) and was closely associated with the rainy season. We analyzed cholera outbreaks, characterized 67 isolates of V. cholerae serogroup O1 in 2015 from patients from Mandalay, and compared them with 22 V. cholerae O1 isolates (12 from Mandalay and 10 from Yangon) in 2014. The isolates carried the classical cholera toxin B subunit ( ctxB ), the toxin-coregulated pilus A ( tcpA ) of Haitian type, and repeat sequence transcriptional regulator ( rstR ) of El Tor type. Two molecular typing methods, pulsed-field gel electrophoresis and multiple-locus variable-number tandem repeat analysis (MLVA), differentiated the 89 isolates into seven pulsotypes and 15 MLVA profiles. Pulsotype Y15 and one MLVA profile (11, 7, 7, 16, 7) were predominantly found in the isolates from cholera outbreaks in Mandalay, 2015. Pulsotypes Y11, Y12, and Y15 with some MLVA profiles were detected in the isolates from two remote areas, Mandalay and Yangon, with temporal changes. These data suggested that cholera spread from the seaside to the inland area in Myanmar.

Lessons learnt from 12 oral cholera vaccine campaigns in resource-poor settings

PubMed Central

Desai, Sachin N; Mogasale, Vittal; Excler, Jean-Louis; Digilio, Laura

2017-01-01

Abstract Improving water and sanitation is the preferred choice for cholera control in the long-term. Nevertheless, vaccination is an available tool that has been shown to be a cost-effective option for cholera prevention in endemic countries or during outbreaks. In 2011 the first low-cost oral cholera vaccine for international use was given prequalification by the World Health Organization (WHO). To increase and prioritize use of the vaccine, WHO created a global stockpile in 2013 from which countries may request oral cholera vaccine for reactive campaigns. WHO has issued specific guidelines for applying for the vaccine, which was previously in short supply (despite prequalification for a second oral vaccine in 2015). The addition of a third WHO-prequalified oral cholera vaccine in 2016 is expected to increase the global stockpile considerably and alleviate supply issues. However, prioritization and best use of the vaccine (e.g. how, when and where to use) will remain challenges. We describe 12 past oral cholera vaccine campaigns, conducted in settings with varying burdens of cholera. These case studies illustrate three key challenges faced in the use of the oral cholera vaccines: regulatory hurdles, cold chain logistics and vaccine coverage and uptake. To pave the way for the introduction of current and future oral cholera vaccines, we discuss operational challenges and make recommendations for future research with respect to each of these challenges. PMID:28479625

Algal blooms in the spread and persistence of cholera.

PubMed

Epstein, P R

1993-01-01

Cholera has been long associated with the seasonality of coastal algal blooms off Bangladesh. Using fluorescent antibody (FA) techniques, microbiologists have now identified a viable, non-cultivable form of Vibrio cholerae in a wide range of marine life, including cyanobacteria (Anabaena variabilis), diatoms (Skeletonema costatum), phaeophytes (Ascophyllum nodosum), in copepod molts, and in freshwater vascular aquatic plants (water hyacinths and duckweed). In unfavourable conditions V. cholerae assumes spore-like forms; with proper nutrients, pH and temperature, it reverts to a readily transmissible and infectious state. Nitrates and phosphates in sewage and fertilizers cause eutrophication, and scientists report an increase in intensity, duration and shifts in the biodiversity of algal blooms in many coastal, brackish and fresh waters worldwide. V. cholerae has been isolated from phyto- and zooplankton in marine and fresh waters near Lima, Peru. V. cholera 01, biotype El Tor, serotype Inaba, may have arrived in the Americas in the bilge of a Chinese freighter. There, in the abundant coastal sea life along the Latin American Pacific coast, nourished by the Humboldt current and eutrophication, it found a reservoir for surviving unfavourable conditions. It is hypothesized that the algae and Vibrio populations grew exponentially; consumed by fish, mollusks and crustacea, a heavy 'inoculum' of carriers infected with V. cholerae was generated and transported into multiple coastal communities.

Cholera in the United States, 1965-1991. Risks at home and abroad.

PubMed

Weber, J T; Levine, W C; Hopkins, D P; Tauxe, R V

1994-03-14

To assess risks for cholera in the United States. Review of published reports of cholera outbreaks and sporadic cases and Centers for Disease Control and Prevention (CDC) memoranda and laboratory reports. Persons with symptomatic laboratory-diagnosed cholera treated in the United States and territories. From 1965 through 1991, 136 cases of cholera were reported. Fifty-three percent of the patients were hospitalized and three persons died (case-fatality rate, 0.02). Ninety-three infections were acquired in the United States and 42 overseas; for one case the source was unknown. Domestically acquired cholera was largely related to the endemic Gulf Coast focus of Vibrio cholerae 01 (56 cases). The major domestic food vehicle was shellfish, particularly crabs harvested from the Gulf of Mexico or nearby estuaries. In 1991, 14 (54%) of 26 domestically acquired cases were caused by food from Ecuador (n = 11) and Thailand (n = 3). During 1991, the first cases of cholera in travelers returning from South America were reported. In 1991, the rate of cholera among air travelers returning from South America was estimated as 0.3 per 100,000; among air travelers returning from Ecuador, 2.6 per 100,000. Cholera remains a small but persistent risk in the United States and for travelers. An endemic focus on the Gulf Coast, the continuing global pandemic, and the epidemic in South America make this likely to continue for years to come. Physicians should know how to diagnose and treat cholera and should report all suspected cases to their state health departments.

Comparing sociocultural features of cholera in three endemic African settings.

PubMed

Schaetti, Christian; Sundaram, Neisha; Merten, Sonja; Ali, Said M; Nyambedha, Erick O; Lapika, Bruno; Chaignat, Claire-Lise; Hutubessy, Raymond; Weiss, Mitchell G

2013-09-18

Cholera mainly affects developing countries where safe water supply and sanitation infrastructure are often rudimentary. Sub-Saharan Africa is a cholera hotspot. Effective cholera control requires not only a professional assessment, but also consideration of community-based priorities. The present work compares local sociocultural features of endemic cholera in urban and rural sites from three field studies in southeastern Democratic Republic of Congo (SE-DRC), western Kenya and Zanzibar. A vignette-based semistructured interview was used in 2008 in Zanzibar to study sociocultural features of cholera-related illness among 356 men and women from urban and rural communities. Similar cross-sectional surveys were performed in western Kenya (n = 379) and in SE-DRC (n = 360) in 2010. Systematic comparison across all settings considered the following domains: illness identification; perceived seriousness, potential fatality and past household episodes; illness-related experience; meaning; knowledge of prevention; help-seeking behavior; and perceived vulnerability. Cholera is well known in all three settings and is understood to have a significant impact on people's lives. Its social impact was mainly characterized by financial concerns. Problems with unsafe water, sanitation and dirty environments were the most common perceived causes across settings; nonetheless, non-biomedical explanations were widespread in rural areas of SE-DRC and Zanzibar. Safe food and water and vaccines were prioritized for prevention in SE-DRC. Safe water was prioritized in western Kenya along with sanitation and health education. The latter two were also prioritized in Zanzibar. Use of oral rehydration solutions and rehydration was a top priority everywhere; healthcare facilities were universally reported as a primary source of help. Respondents in SE-DRC and Zanzibar reported cholera as affecting almost everybody without differentiating much for gender, age and class. In contrast, in western

Comparing sociocultural features of cholera in three endemic African settings

PubMed Central

2013-01-01

Background Cholera mainly affects developing countries where safe water supply and sanitation infrastructure are often rudimentary. Sub-Saharan Africa is a cholera hotspot. Effective cholera control requires not only a professional assessment, but also consideration of community-based priorities. The present work compares local sociocultural features of endemic cholera in urban and rural sites from three field studies in southeastern Democratic Republic of Congo (SE-DRC), western Kenya and Zanzibar. Methods A vignette-based semistructured interview was used in 2008 in Zanzibar to study sociocultural features of cholera-related illness among 356 men and women from urban and rural communities. Similar cross-sectional surveys were performed in western Kenya (n = 379) and in SE-DRC (n = 360) in 2010. Systematic comparison across all settings considered the following domains: illness identification; perceived seriousness, potential fatality and past household episodes; illness-related experience; meaning; knowledge of prevention; help-seeking behavior; and perceived vulnerability. Results Cholera is well known in all three settings and is understood to have a significant impact on people’s lives. Its social impact was mainly characterized by financial concerns. Problems with unsafe water, sanitation and dirty environments were the most common perceived causes across settings; nonetheless, non-biomedical explanations were widespread in rural areas of SE-DRC and Zanzibar. Safe food and water and vaccines were prioritized for prevention in SE-DRC. Safe water was prioritized in western Kenya along with sanitation and health education. The latter two were also prioritized in Zanzibar. Use of oral rehydration solutions and rehydration was a top priority everywhere; healthcare facilities were universally reported as a primary source of help. Respondents in SE-DRC and Zanzibar reported cholera as affecting almost everybody without differentiating much for gender, age

Expression of cholera toxin B subunit in transgenic tomato plants.

PubMed

Jani, Dewal; Meena, Laxman Singh; Rizwan-ul-Haq, Quazi Mohammad; Singh, Yogendra; Sharma, Arun K; Tyagi, Akhilesh K

2002-10-01

Cholera toxin, secreted by Vibrio cholerae, consists of A and B subunits. The latter binds to G(M1)-ganglioside receptors as a pentamer (approximately 55 kDa). Tomato plants were transformed with the gene encoding cholera toxin B subunit (ctxB) along with an endoplasmic reticulum retention signal (SEKDEL) under the control of the CaMV 35S promoter via Agrobacterium-mediated transformation. PCR and Southern analysis confirmed the presence of the ctxB gene in transformed tomato plants. Northern analysis showed the presence of the ctxB-specific transcript. Immunoblot assays of the plant-derived protein extract showed the presence of cholera toxin subunit B (CTB) with mobility similar to purified CTB from V. cholerae. Both tomato leaves and fruits expressed CTB at levels up to 0.02 and 0.04% of total soluble protein, respectively. The G(M1)-ELISA showed that the plant-derived CTB bound specifically to G(M1)-ganglioside receptor, suggesting that it retained its native pentameric form. This study forms a basis for exploring the utility of CTB to develop tomato-based edible vaccines against cholera.

Satellites and Human Health: Potential for Tracking Cholera Outbreaks

NASA Astrophysics Data System (ADS)

Jutla, A. S.; Akanda, A. S.; Islam, S.

2009-12-01

Cholera continues to be a significant health threat across the globe. The pattern and magnitude of the seven global pandemics suggest that cholera outbreaks primarily originate in coastal regions and spread inland through secondary means. Cholera bacteria show strong association with zooplankton and phytoplankton abundance in coastal ecosystems. Characterization of space-time variability of chlorophyll, a surrogate for phytoplankton abundance, in Northern Bay of Bengal (BoB) is an essential step to develop any methodology for tracking cholera in the Bengal Delta from space. Using ten years of satellite data, this study (a) quantifies the space-time distribution of chlorophyll in BoB region and (b) presents a hypothesis as to how coastal plankton may be related with cholera outbreaks. Preliminary results suggest that variability of chlorophyll at daily scale, irrespective of spatial averaging, resembles white noise. At a monthly scale, chlorophyll shows distinct annual seasonality and chlorophyll values are significantly higher close to the coast than those in the offshore regions. At pixel level (9 km) on monthly scale, on the other hand, chlorophyll does not exhibit much persistence in time. With increased spatial averaging, temporal persistence of monthly chlorophyll increases and lag one autocorrelation stabilizes around 0.60 for 1200 km2 or larger areal averages. Spatial analyses of chlorophyll suggest that coastal region in BoB have a stable sill at 100 km range. Using satellite chlorophyll data, we observe that phytoplankton blooms occur every year in BoB, yet severe cholera outbreaks happen in certain years. This study provides a working hypothesis on how BoB coastal plankton blooms aided by regional hydroclimatic processes may lead to possible cholera outbreaks in Bengal Delta.

Cholera between 1991 and 1997 in Mexico was associated with infection by classical, El Tor, and El Tor variants of Vibrio cholerae.

PubMed

Alam, Munirul; Nusrin, Suraia; Islam, Atiqul; Bhuiyan, Nurul A; Rahim, Niaz; Delgado, Gabriela; Morales, Rosario; Mendez, Jose Luis; Navarro, Armando; Gil, Ana I; Watanabe, Haruo; Morita, Masatomo; Nair, G Balakrish; Cravioto, Alejandro

2010-10-01

Vibrio cholerae O1 biotype El Tor (ET), the cause of the current 7th pandemic, has recently been replaced in Asia and Africa by an altered ET biotype possessing cholera toxin (CTX) of the classical (CL) biotype that originally caused the first six pandemics before becoming extinct in the 1980s. Until recently, the ET prototype was the biotype circulating in Peru; a detailed understanding of the evolutionary trend of V. cholerae causing endemic cholera in Latin America is lacking. The present retrospective microbiological, molecular, and phylogenetic study of V. cholerae isolates recovered in Mexico (n = 91; 1983 to 1997) shows the existence of the pre-1991 CL biotype and the ET and CL biotypes together with the altered ET biotype in both epidemic and endemic cholera between 1991 and 1997. According to sero- and biotyping data, the altered ET, which has shown predominance in Mexico since 1991, emerged locally from ET and CL progenitors that were found coexisting until 1997. In Latin America, ET and CL variants shared a variable number of phenotypic markers, while the altered ET strains had genes encoding the CL CTX (CTX(CL)) prophage, ctxB(CL) and rstR(CL), in addition to resident rstR(ET), as the underlying regional signature. The distinct regional fingerprints for ET in Mexico and Peru and their divergence from ET in Asia and Africa, as confirmed by subclustering patterns in a pulsed-field gel electrophoresis (NotI)-based dendrogram, suggest that the Mexico epidemic in 1991 may have been a local event and not an extension of the epidemics occurring in Asia and South America. Finally, the CL biotype reservoir in Mexico is unprecedented and must have contributed to the changing epidemiology of global cholera in ways that need to be understood.

Cholera Fact Sheet

MedlinePlus

... of more than 50 partners active in cholera control globally, including academic institutions, non-governmental organisations and United Nations agencies. Through the GTFCC and with support from donors, WHO works to: promote the design and implementation of global strategies to contribute to ...

Protection against cholera from killed whole-cell oral cholera vaccines: a systematic review and meta-analysis.

PubMed

Bi, Qifang; Ferreras, Eva; Pezzoli, Lorenzo; Legros, Dominique; Ivers, Louise C; Date, Kashmira; Qadri, Firdausi; Digilio, Laura; Sack, David A; Ali, Mohammad; Lessler, Justin; Luquero, Francisco J; Azman, Andrew S

2017-10-01

Killed whole-cell oral cholera vaccines (kOCVs) are becoming a standard cholera control and prevention tool. However, vaccine efficacy and direct effectiveness estimates have varied, with differences in study design, location, follow-up duration, and vaccine composition posing challenges for public health decision making. We did a systematic review and meta-analysis to generate average estimates of kOCV efficacy and direct effectiveness from the available literature. For this systematic review and meta-analysis, we searched PubMed, Embase, Scopus, and the Cochrane Review Library on July 9, 2016, and ISI Web of Science on July 11, 2016, for randomised controlled trials and observational studies that reported estimates of direct protection against medically attended confirmed cholera conferred by kOCVs. We included studies published on any date in English, Spanish, French, or Chinese. We extracted from the published reports the primary efficacy and effectiveness estimates from each study and also estimates according to number of vaccine doses, duration, and age group. The main study outcome was average efficacy and direct effectiveness of two kOCV doses, which we estimated with random-effect models. This study is registered with PROSPERO, number CRD42016048232. Seven trials (with 695 patients with cholera) and six observational studies (217 patients with cholera) met the inclusion criteria, with an average two-dose efficacy of 58% (95% CI 42-69, I 2 =58%) and effectiveness of 76% (62-85, I 2 =0). Average two-dose efficacy in children younger than 5 years (30% [95% CI 15-42], I 2 =0%) was lower than in those 5 years or older (64% [58-70], I 2 =0%; p<0·0001). Two-dose efficacy estimates of kOCV were similar during the first 2 years after vaccination, with estimates of 56% (95% CI 42-66, I 2 =45%) in the first year and 59% (49-67, I 2 =0) in the second year. The efficacy reduced to 39% (13 to 57, I 2 =48%) in the third year, and 26% (-46 to 63, I 2 =74%) in the fourth

[Epidemic Cholera and American Reform Movements in the 19th Century].

PubMed

Kim, Seohyung

2015-12-01

The 19th century was the age of great reform in American history. After constructing of the canal and railroads, the industrialization began and American society changed so rapidly. In this period, there were so many social crisis and American people tried to solve these problems within the several reform movements. These reform movements were the driving forces to control cholera during the 19th century. Cholera was the endemic disease in Bengal, India, but after the 19th century it had spread globally by the development of trade networks. The 1832 cholera in the United States was the first epidemic cholera in American history. The mortality of cholera was so high, but it was very hard to find out the cause of this fatal infectious disease. So, different social discourses happened to control epidemic cholera in the 19th century, these can be understood within the similar context of American reform movements during this period. Board of Health in New York States made a new public health act to control cholera in 1832, it was ineffective. Some people insisted that the cause of this infectious disease was the corruption of the United States. They emphasized unjust and immoral system in American society. Moral reform expanded to Nativism, because lots of Irish immigrants were the victims of cholera. So, epidemic cholera was the opportunity to spread the desire for moral reform. To control cholera in 1849, the sanitary reform in Britain had affected. The fact that it was so important to improve and maintain the water quality for the control and prevention of disease spread, the sanitary reform happened. There were two different sphere of the sanitary reform. The former was the private reform to improve sewer or privy, the latter was the public reform to build sewage facilities. The 1849 cholera had an important meaning, because the social discourse, which had emphasized the sanitation of people or home expanded to the public sphere. When cholera broke out in 1866 again

[Preparation and evaluation of coagglutination reagents for the identification of Vibrio cholerae 01. Its trial during a cholera outbreak in Minatitlán, Veracruz].

PubMed

González Bonilla, C; Villanueva Zamudio, A; Bolaños Monrroy, G; Giono Cerezo, S; Valdespino Gómez, J L

1992-01-01

This study was realized in Minatitlán, Veracruz during a cholera outbreak. 169 rectal swabs were taken from hilles and their contacts. They were transfer alkaline peptone water for enrichment to V. cholerae and incubated for 8 hrs to 37 degrees C, 70 were positive for V. cholerae in both techniques. The coagglutination was done with a reagent prepared at the Instituto de Diagnóstico y Referencia Epidemiológicos of México and the culture were also performed in the same Institute. We obtained 100% of sensitivity and specificity of co-agglutination in relation with culture. This results gave the possibility to use this kind or reagents for a rapid presumptive diagnosis of cholera.

Vector potential of houseflies (Musca domestica) in the transmission of Vibrio cholerae in India.

PubMed

Fotedar, R

2001-01-15

It is well known that diarrhoeal infections due to Vibrio cholerae are spread through fecal-oral route of transmission. In the present study an attempt was made to isolate and identify V. cholerae from houseflies, Musca domestica collected from a low socioeconomic area in Delhi, India, where an outbreak of cholera was encountered. Of the ten fly pools examined, six (60%) were positive for V. cholerae. Of these six pools, three (50%) showed V. cholerae Ogawa T2 El Tor and one (17.5%) V. cholerae non-O1. Two isolates could not be typed. During the outbreak period, V. cholerae Ogawa T2 El Tor was isolated from stools of patients suffering from diarrhoea. These findings suggest that houseflies act as mechanical vectors of V. cholerae biotype El Tor and may help in their dissemination. The present study highlights the recovery of V. cholerae El Tor from M. domestica which, to the authors knowledge, has not been reported previously.

Plasma and memory B cell responses targeting O-specific polysaccharide (OSP) are associated with protection against Vibrio cholerae O1 infection among household contacts of cholera patients in Bangladesh.

PubMed

Aktar, Amena; Rahman, M Arifur; Afrin, Sadia; Akter, Aklima; Uddin, Taher; Yasmin, Tahirah; Sami, Md Israk Nur; Dash, Pinki; Jahan, Sultana Rownok; Chowdhury, Fahima; Khan, Ashraful I; LaRocque, Regina C; Charles, Richelle C; Bhuiyan, Taufiqur Rahman; Mandlik, Anjali; Kelly, Meagan; Kováč, Pavol; Xu, Peng; Calderwood, Stephen B; Harris, Jason B; Qadri, Firdausi; Ryan, Edward T

2018-04-01

The mediators of protection against cholera, a severe dehydrating illness of humans caused by Vibrio cholerae, are unknown. We have previously shown that plasma IgA as well as memory B IgG cells targeting lipopolysaccharide (LPS) of Vibrio cholerae O1 correlate with protection against V. cholerae O1 infection among household contacts of cholera patients. Protection against cholera is serogroup specific, and serogroup specificity is defined by the O-specific polysaccharide (OSP) component of LPS. Therefore, we prospectively followed household contacts of cholera patients to determine whether OSP-specific immune responses present at the time of enrollment are associated with protection against V. cholerae infection. In this study, we enrolled two hundred forty two household contacts of one hundred fifty index patients who were infected with Vibrio cholerae. We determined OSP-specific memory B cells and plasma IgA, IgG and IgM antibody responses on study entry (day 2). The presence of OSP-specific plasma IgA, IgM, and IgG antibody responses on study entry were associated with a decrease in the risk of infection in household contacts (IgA, p = 0.015; IgM, p = 0.01, and IgG, p = 0.024). In addition, the presence of OSP-specific IgG memory B cell responses in peripheral blood on study entry was also associated with a decreased risk of infection (44% reduction; 95% CI: 31.1 to 99.8) in contacts. No protection was associated with cholera toxin B subunit (CtxB)-specific memory B cell responses. These results suggest that immune responses that target OSP, both in plasma and memory responses, may be important in mediating protection against infection with V. cholerae O1.

Plasma and memory B cell responses targeting O-specific polysaccharide (OSP) are associated with protection against Vibrio cholerae O1 infection among household contacts of cholera patients in Bangladesh

PubMed Central

Aktar, Amena; Rahman, M. Arifur; Afrin, Sadia; Akter, Aklima; Uddin, Taher; Yasmin, Tahirah; Sami, Md. Israk Nur; Dash, Pinki; Jahan, Sultana Rownok; Chowdhury, Fahima; Khan, Ashraful I.; LaRocque, Regina C.; Charles, Richelle C.; Bhuiyan, Taufiqur Rahman; Mandlik, Anjali; Kelly, Meagan; Kováč, Pavol; Xu, Peng; Calderwood, Stephen B.; Harris, Jason B.; Ryan, Edward T.

2018-01-01

Background The mediators of protection against cholera, a severe dehydrating illness of humans caused by Vibrio cholerae, are unknown. We have previously shown that plasma IgA as well as memory B IgG cells targeting lipopolysaccharide (LPS) of Vibrio cholerae O1 correlate with protection against V. cholerae O1 infection among household contacts of cholera patients. Protection against cholera is serogroup specific, and serogroup specificity is defined by the O-specific polysaccharide (OSP) component of LPS. Therefore, we prospectively followed household contacts of cholera patients to determine whether OSP-specific immune responses present at the time of enrollment are associated with protection against V. cholerae infection. Methodology In this study, we enrolled two hundred forty two household contacts of one hundred fifty index patients who were infected with Vibrio cholerae. We determined OSP-specific memory B cells and plasma IgA, IgG and IgM antibody responses on study entry (day 2). Principle findings The presence of OSP-specific plasma IgA, IgM, and IgG antibody responses on study entry were associated with a decrease in the risk of infection in household contacts (IgA, p = 0.015; IgM, p = 0.01, and IgG, p = 0.024). In addition, the presence of OSP-specific IgG memory B cell responses in peripheral blood on study entry was also associated with a decreased risk of infection (44% reduction; 95% CI: 31.1 to 99.8) in contacts. No protection was associated with cholera toxin B subunit (CtxB)-specific memory B cell responses. Conclusion These results suggest that immune responses that target OSP, both in plasma and memory responses, may be important in mediating protection against infection with V. cholerae O1. PMID:29684006

Cholera Toxin Production during Anaerobic Trimethylamine N-Oxide Respiration Is Mediated by Stringent Response in Vibrio cholerae*

PubMed Central

Oh, Young Taek; Park, Yongjin; Yoon, Mi Young; Bari, Wasimul; Go, Junhyeok; Min, Kyung Bae; Raskin, David M.; Lee, Kang-Mu; Yoon, Sang Sun

2014-01-01

As a facultative anaerobe, Vibrio cholerae can grow by anaerobic respiration. Production of cholera toxin (CT), a major virulence factor of V. cholerae, is highly promoted during anaerobic growth using trimethylamine N-oxide (TMAO) as an alternative electron acceptor. Here, we investigated the molecular mechanisms of TMAO-stimulated CT production and uncovered the crucial involvement of stringent response in this process. V. cholerae 7th pandemic strain N16961 produced a significantly elevated level of ppGpp, the bacterial stringent response alarmone, during anaerobic TMAO respiration. Bacterial viability was impaired, and DNA replication was also affected under the same growth condition, further suggesting that stringent response is induced. A ΔrelA ΔspoT ppGpp overproducer strain produced an enhanced level of CT, whereas anaerobic growth via TMAO respiration was severely inhibited. In contrast, a ppGpp-null strain (ΔrelA ΔspoT ΔrelV) grew substantially better, but produced no CT, suggesting that CT production and bacterial growth are inversely regulated in response to ppGpp accumulation. Bacterial capability to produce CT was completely lost when the dksA gene, which encodes a protein that works cooperatively with ppGpp, was deleted. In the ΔdksA mutant, stringent response growth inhibition was alleviated, further supporting the inverse regulation of CT production and anaerobic growth. In vivo virulence of ΔrelA ΔspoT ΔrelV or ΔdksA mutants was significantly attenuated. The ΔrelA ΔspoT mutant maintained virulence when infected with exogenous TMAO despite its defective growth. Together, our results reveal that stringent response is activated under TMAO-stimulated anaerobic growth, and it regulates CT production in a growth-dependent manner in V. cholerae. PMID:24648517

Epidemic cholera in a crowded urban environment, Port-au-Prince, Haiti.

PubMed

Dunkle, Stacie E; Mba-Jonas, Adamma; Loharikar, Anagha; Fouché, Bernadette; Peck, Mireille; Ayers, Tracy; Archer, W Roodly; De Rochars, Valery M Beau; Bender, Thomas; Moffett, Daphne B; Tappero, Jordan W; Dahourou, George; Roels, Thierry; Quick, Robert

2011-11-01

We conducted a case-control study to investigate factors associated with epidemic cholera. Water treatment and handwashing may have been protective, highlighting the need for personal hygiene for cholera prevention in contaminated urban environments. We also found a diverse diet, a possible proxy for improved nutrition, was protective against cholera.

Bayesian structured additive regression modeling of epidemic data: application to cholera

PubMed Central

2012-01-01

Background A significant interest in spatial epidemiology lies in identifying associated risk factors which enhances the risk of infection. Most studies, however, make no, or limited use of the spatial structure of the data, as well as possible nonlinear effects of the risk factors. Methods We develop a Bayesian Structured Additive Regression model for cholera epidemic data. Model estimation and inference is based on fully Bayesian approach via Markov Chain Monte Carlo (MCMC) simulations. The model is applied to cholera epidemic data in the Kumasi Metropolis, Ghana. Proximity to refuse dumps, density of refuse dumps, and proximity to potential cholera reservoirs were modeled as continuous functions; presence of slum settlers and population density were modeled as fixed effects, whereas spatial references to the communities were modeled as structured and unstructured spatial effects. Results We observe that the risk of cholera is associated with slum settlements and high population density. The risk of cholera is equal and lower for communities with fewer refuse dumps, but variable and higher for communities with more refuse dumps. The risk is also lower for communities distant from refuse dumps and potential cholera reservoirs. The results also indicate distinct spatial variation in the risk of cholera infection. Conclusion The study highlights the usefulness of Bayesian semi-parametric regression model analyzing public health data. These findings could serve as novel information to help health planners and policy makers in making effective decisions to control or prevent cholera epidemics. PMID:22866662

Biochemical and full genome sequence analyses of clinical Vibrio cholerae isolates in Mexico reveals the presence of novel V. cholerae strains.

PubMed

Díaz-Quiñonez, José Alberto; Hernández-Monroy, Irma; Montes-Colima, Norma Angélica; Moreno-Pérez, María Asunción; Galicia-Nicolás, Adriana Guadalupe; López-Martínez, Irma; Ruiz-Matus, Cuitláhuac; Kuri-Morales, Pablo; Ortíz-Alcántara, Joanna María; Garcés-Ayala, Fabiola; Ramírez-González, José Ernesto

2016-05-01

The first week of September 2013, the National Epidemiological Surveillance System identified two cases of cholera in Mexico City. The cultures of both samples were confirmed as Vibrio cholerae serogroup O1, serotype Ogawa, biotype El Tor. Initial analyses by PFGE and by PCR-amplification of the virulence genes, suggested that both strains were similar, but different from those previously reported in Mexico. The following week, four more cases were identified in a community in the state of Hidalgo, located 121 km northeast of Mexico City. Thereafter a cholera outbreak started in the region of La Huasteca. Genomic analyses of the four strains obtained in this study confirmed the presence of Pathogenicity Islands VPI-1 and -2, VSP-1 and -2, and of the integrative element SXT. The genomic structure of the 4 isolates was similar to that of V. cholerae strain 2010 EL-1786, identified during the epidemic in Haiti in 2010. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Toxigenic Vibrio cholerae O1 in vegetables and fish raised in wastewater irrigated fields and stabilization ponds during a non-cholera outbreak period in Morogoro, Tanzania: an environmental health study.

PubMed

Hounmanou, Yaovi M G; Mdegela, Robinson H; Dougnon, Tamègnon V; Mhongole, Ofred J; Mayila, Edward S; Malakalinga, Joseph; Makingi, George; Dalsgaard, Anders

2016-10-18

Cholera, one of the world's deadliest infectious diseases, remains rampant and frequent in Tanzania and thus hinders existing control measures. The present study was undertaken to evaluate the occurrence of toxigenic Vibrio cholerae O1 in wastewater, fish and vegetables during a non-outbreak period in Morogoro, Tanzania. From October 2014 to February 2015, 60 wastewater samples, 60 fish samples from sewage stabilization ponds and 60 wastewater irrigated vegetable samples were collected. Samples were cultured for identification of V. cholerae using conventional bacteriological methods. Isolates were confirmed as V. cholerae by detection of the outer membrane protein gene (ompW) using polymerase chain reaction (PCR). Isolates were further tested for antibiotic susceptibility and presence of virulence genes including, cholera enterotoxin gene (ctx), the toxin co-regulated pilus gene (tcpA) and the haemolysin gene (hlyA). The prevalence of V. cholerae in wastewater, vegetables and fish was 36.7, 21.7 and 23.3 %, respectively. Two isolates from fish gills were V. cholerae O1 and tested positive for ctx and tcpA. One of these contained in addition the hlyA gene while five isolates from fish intestines tested positive for tcpA. All V. cholerae isolates were resistant to ampicillin, amoxicillin and some to tetracycline, but sensitive to gentamicin, chloramphenicol, and ciprofloxacin. Our results show that toxigenic and drug-resistant V. cholerae O1 species are present and persist in aquatic environments during a non-cholera outbreak period. This is of public health importance and shows that such environments may be important as reservoirs and in the transmission of V. cholerae O1.

El Niño and the shifting geography of cholera in Africa.

PubMed

Moore, Sean M; Azman, Andrew S; Zaitchik, Benjamin F; Mintz, Eric D; Brunkard, Joan; Legros, Dominique; Hill, Alexandra; McKay, Heather; Luquero, Francisco J; Olson, David; Lessler, Justin

2017-04-25

The El Niño Southern Oscillation (ENSO) and other climate patterns can have profound impacts on the occurrence of infectious diseases ranging from dengue to cholera. In Africa, El Niño conditions are associated with increased rainfall in East Africa and decreased rainfall in southern Africa, West Africa, and parts of the Sahel. Because of the key role of water supplies in cholera transmission, a relationship between El Niño events and cholera incidence is highly plausible, and previous research has shown a link between ENSO patterns and cholera in Bangladesh. However, there is little systematic evidence for this link in Africa. Using high-resolution mapping techniques, we find that the annual geographic distribution of cholera in Africa from 2000 to 2014 changes dramatically, with the burden shifting to continental East Africa-and away from Madagascar and portions of southern, Central, and West Africa-where almost 50,000 additional cases occur during El Niño years. Cholera incidence during El Niño years was higher in regions of East Africa with increased rainfall, but incidence was also higher in some areas with decreased rainfall, suggesting a complex relationship between rainfall and cholera incidence. Here, we show clear evidence for a shift in the distribution of cholera incidence throughout Africa in El Niño years, likely mediated by El Niño's impact on local climatic factors. Knowledge of this relationship between cholera and climate patterns coupled with ENSO forecasting could be used to notify countries in Africa when they are likely to see a major shift in their cholera risk.

El Niño and the shifting geography of cholera in Africa

PubMed Central

Moore, Sean M.; Azman, Andrew S.; Zaitchik, Benjamin F.; Mintz, Eric D.; Brunkard, Joan; Legros, Dominique; Hill, Alexandra; McKay, Heather; Luquero, Francisco J.; Olson, David; Lessler, Justin

2017-01-01

The El Niño Southern Oscillation (ENSO) and other climate patterns can have profound impacts on the occurrence of infectious diseases ranging from dengue to cholera. In Africa, El Niño conditions are associated with increased rainfall in East Africa and decreased rainfall in southern Africa, West Africa, and parts of the Sahel. Because of the key role of water supplies in cholera transmission, a relationship between El Niño events and cholera incidence is highly plausible, and previous research has shown a link between ENSO patterns and cholera in Bangladesh. However, there is little systematic evidence for this link in Africa. Using high-resolution mapping techniques, we find that the annual geographic distribution of cholera in Africa from 2000 to 2014 changes dramatically, with the burden shifting to continental East Africa—and away from Madagascar and portions of southern, Central, and West Africa—where almost 50,000 additional cases occur during El Niño years. Cholera incidence during El Niño years was higher in regions of East Africa with increased rainfall, but incidence was also higher in some areas with decreased rainfall, suggesting a complex relationship between rainfall and cholera incidence. Here, we show clear evidence for a shift in the distribution of cholera incidence throughout Africa in El Niño years, likely mediated by El Niño’s impact on local climatic factors. Knowledge of this relationship between cholera and climate patterns coupled with ENSO forecasting could be used to notify countries in Africa when they are likely to see a major shift in their cholera risk. PMID:28396423

The population structure of Vibrio cholerae from the Chandigarh Region of Northern India.

PubMed

Abd El Ghany, Moataz; Chander, Jagadish; Mutreja, Ankur; Rashid, Mamoon; Hill-Cawthorne, Grant A; Ali, Shahjahan; Naeem, Raeece; Thomson, Nicholas R; Dougan, Gordon; Pain, Arnab

2014-07-01

Cholera infection continues to be a threat to global public health. The current cholera pandemic associated with Vibrio cholerae El Tor has now been ongoing for over half a century. Thirty-eight V. cholerae El Tor isolates associated with a cholera outbreak in 2009 from the Chandigarh region of India were characterised by a combination of microbiology, molecular typing and whole-genome sequencing. The genomic analysis indicated that two clones of V. cholera circulated in the region and caused disease during this time. These clones fell into two distinct sub-clades that map independently onto wave 3 of the phylogenetic tree of seventh pandemic V. cholerae El Tor. Sequence analyses of the cholera toxin gene, the Vibrio seventh Pandemic Island II (VSPII) and SXT element correlated with this phylogenetic position of the two clades on the El Tor tree. The clade 2 isolates, characterized by a drug-resistant profile and the expression of a distinct cholera toxin, are closely related to the recent V. cholerae isolated elsewhere, including Haiti, but fell on a distinct branch of the tree, showing they were independent outbreaks. Multi-Locus Sequence Typing (MLST) distinguishes two sequence types among the 38 isolates, that did not correspond to the clades defined by whole-genome sequencing. Multi-Locus Variable-length tandem-nucleotide repeat Analysis (MLVA) identified 16 distinct clusters. The use of whole-genome sequencing enabled the identification of two clones of V. cholerae that circulated during the 2009 Chandigarh outbreak. These clones harboured a similar structure of ICEVchHai1 but differed mainly in the structure of CTX phage and VSPII. The limited capacity of MLST and MLVA to discriminate between the clones that circulated in the 2009 Chandigarh outbreak highlights the value of whole-genome sequencing as a route to the identification of further genetic markers to subtype V. cholerae isolates.

Inhibition of virulence potential of Vibrio cholerae by natural compounds

PubMed Central

Yamasaki, Shinji; Asakura, Masahiro; Neogi, Sucharit Basu; Hinenoya, Atsushi; Iwaoka, Emiko; Aoki, Shunji

2011-01-01

The rise in multi-drug resistant Vibrio cholerae strains is a big problem in treatment of patients suffering from severe cholera. Only a few studies have evaluated the potential of natural compounds against V. cholerae. Extracts from plants like ‘neem’, ‘guazuma’, ‘daio’, apple, hop, green tea and elephant garlic have been shown to inhibit bacterial growth or the secreted cholera toxin (CT). However, inhibiting bacterial growth like common antimicrobial agents may also impose selective pressure facilitating development of resistant strains. A natural compound that can inhibit virulence in V. cholerae is an alternative choice for remedy. Recently, some common spices were examined to check their inhibitory capacity against virulence expression of V. cholerae. Among them methanol extracts of red chili, sweet fennel and white pepper could substantially inhibit CT production. Fractionation of red chili methanol extracts indicated a hydrophobic nature of the inhibitory compound(s), and the n-hexane and 90 per cent methanol fractions could inhibit >90 per cent of CT production. Purification and further fractionation revealed that capsaicin is one of the major components among these red chili fractions. Indeed, capsaicin inhibited the production of CT in various V. cholerae strains regardless of serogroups and biotypes. The quantitative reverse transcription real-time PCR assay revealed that capsaicin dramatically reduced the expression of major virulence-related genes such as ctxA, tcpA and toxT but enhanced the expression of hns gene that transcribes a global prokaryotic gene regulator (H-NS). This indicates that the repression of CT production by capsaicin or red chili might be due to the repression of virulence genes transcription by H-NS. Regular intake of spices like red chili might be a good approach to fight against devastating cholera. PMID:21415500

Inhibition of virulence potential of Vibrio cholerae by natural compounds.

PubMed

Yamasaki, Shinji; Asakura, Masahiro; Neogi, Sucharit Basu; Hinenoya, Atsushi; Iwaoka, Emiko; Aoki, Shunji

2011-02-01

The rise in multi-drug resistant Vibrio cholerae strains is a big problem in treatment of patients suffering from severe cholera. Only a few studies have evaluated the potential of natural compounds against V. cholerae. Extracts from plants like 'neem', 'guazuma', 'daio', apple, hop, green tea and elephant garlic have been shown to inhibit bacterial growth or the secreted cholera toxin (CT). However, inhibiting bacterial growth like common antimicrobial agents may also impose selective pressure facilitating development of resistant strains. A natural compound that can inhibit virulence in V. cholerae is an alternative choice for remedy. Recently, some common spices were examined to check their inhibitory capacity against virulence expression of V. cholerae. Among them methanol extracts of red chili, sweet fennel and white pepper could substantially inhibit CT production. Fractionation of red chili methanol extracts indicated a hydrophobic nature of the inhibitory compound(s), and the n-hexane and 90 per cent methanol fractions could inhibit >90 per cent of CT production. Purification and further fractionation revealed that capsaicin is one of the major components among these red chili fractions. Indeed, capsaicin inhibited the production of CT in various V. cholerae strains regardless of serogroups and biotypes. The quantitative reverse transcription real-time PCR assay revealed that capsaicin dramatically reduced the expression of major virulence-related genes such as ctxA, tcpA and toxT but enhanced the expression of hns gene that transcribes a global prokaryotic gene regulator (H-NS). This indicates that the repression of CT production by capsaicin or red chili might be due to the repression of virulence genes transcription by H-NS. Regular intake of spices like red chili might be a good approach to fight against devastating cholera.

Cholera in Thomas Mann's Death in Venice.

PubMed

Rütten, Thomas

2009-01-01

The article sets the cholera motif in Thomas Mann's famous novella Death in Venice against the historical context from which it partially originates. It is shown that this motif, while undoubtedly appropriated to serve Mann's own poetic ends, has a solid grounding in historical and autobiographical fact, thus blurring the boundaries between fact and fiction. The article illustrates the verifiable events of the outbreak of the Venetian cholera epidemic in May 1911, which Mann partly witnessed himself, during a holiday trip to Brioni and Venice, and partly heard and read about. It is established that Thomas Mann's account of the cholera in Venice in his novella is characterised by a rare and almost preternatural insightfulness into an otherwise murky affair that was marked by rumours, speculations and denials.

Modelling cholera epidemics: the role of waterways, human mobility and sanitation

PubMed Central

Mari, L.; Bertuzzo, E.; Righetto, L.; Casagrandi, R.; Gatto, M.; Rodriguez-Iturbe, I.; Rinaldo, A.

2012-01-01

We investigate the role of human mobility as a driver for long-range spreading of cholera infections, which primarily propagate through hydrologically controlled ecological corridors. Our aim is to build a spatially explicit model of a disease epidemic, which is relevant to both social and scientific issues. We present a two-layer network model that accounts for the interplay between epidemiological dynamics, hydrological transport and long-distance dissemination of the pathogen Vibrio cholerae owing to host movement, described here by means of a gravity-model approach. We test our model against epidemiological data recorded during the extensive cholera outbreak occurred in the KwaZulu-Natal province of South Africa during 2000–2001. We show that long-range human movement is fundamental in quantifying otherwise unexplained inter-catchment transport of V. cholerae, thus playing a key role in the formation of regional patterns of cholera epidemics. We also show quantitatively how heterogeneously distributed drinking water supplies and sanitation conditions may affect large-scale cholera transmission, and analyse the effects of different sanitation policies. PMID:21752809

Modelling cholera epidemics: the role of waterways, human mobility and sanitation.

PubMed

Mari, L; Bertuzzo, E; Righetto, L; Casagrandi, R; Gatto, M; Rodriguez-Iturbe, I; Rinaldo, A

2012-02-07

We investigate the role of human mobility as a driver for long-range spreading of cholera infections, which primarily propagate through hydrologically controlled ecological corridors. Our aim is to build a spatially explicit model of a disease epidemic, which is relevant to both social and scientific issues. We present a two-layer network model that accounts for the interplay between epidemiological dynamics, hydrological transport and long-distance dissemination of the pathogen Vibrio cholerae owing to host movement, described here by means of a gravity-model approach. We test our model against epidemiological data recorded during the extensive cholera outbreak occurred in the KwaZulu-Natal province of South Africa during 2000-2001. We show that long-range human movement is fundamental in quantifying otherwise unexplained inter-catchment transport of V. cholerae, thus playing a key role in the formation of regional patterns of cholera epidemics. We also show quantitatively how heterogeneously distributed drinking water supplies and sanitation conditions may affect large-scale cholera transmission, and analyse the effects of different sanitation policies.

Cholera - Multiple Languages

MedlinePlus

... XYZ List of All Topics All Cholera - Multiple Languages To use the sharing features on this page, please enable JavaScript. Spanish (español) ... Bethesda, MD 20894 U.S. Department of Health and Human Services National Institutes of Health Page last updated on 25 April 2018

Antimicrobial Resistance Risks of Cholera Prophylaxis for United Nations Peacekeepers

PubMed Central

Lewnard, Joseph A.; Pitzer, Virginia E.; Cohen, Ted

2017-01-01

ABSTRACT More than 5 years after a United Nations peacekeeping battalion introduced cholera to Haiti, over 150,000 peacekeepers continue to be deployed annually from countries where cholera is endemic. The United Nations has thus far declined to provide antimicrobial chemoprophylaxis to peacekeepers, a policy based largely on concerns that the risks of drug resistance generation and spread would outweigh the potential benefits of preventing future cholera importations. In this study, we sought to better understand the relative benefits and risks of cholera chemoprophylaxis for peacekeepers in terms of antibiotic resistance. Using a stochastic model to quantify the potential impact of chemoprophylaxis on importation and transmission of drug-resistant and drug-sensitive Vibrio cholerae, we found that chemoprophylaxis would decrease the probability of cholera importation but would increase the expected number of drug-resistant infections if an importation event were to occur. Despite this potential increase, we found that at least 10 drug-sensitive infections would likely be averted per excess drug-resistant infection under a wide range of assumptions about the underlying prevalence of drug resistance and risk of acquired resistance. Given these findings, policymakers should reconsider whether the potential resistance risks of providing antimicrobial chemoprophylaxis to peacekeepers are sufficient to outweigh the anticipated benefits. PMID:28533237

Antimicrobial Resistance Risks of Cholera Prophylaxis for United Nations Peacekeepers.

PubMed

Kunkel, Amber; Lewnard, Joseph A; Pitzer, Virginia E; Cohen, Ted

2017-08-01

More than 5 years after a United Nations peacekeeping battalion introduced cholera to Haiti, over 150,000 peacekeepers continue to be deployed annually from countries where cholera is endemic. The United Nations has thus far declined to provide antimicrobial chemoprophylaxis to peacekeepers, a policy based largely on concerns that the risks of drug resistance generation and spread would outweigh the potential benefits of preventing future cholera importations. In this study, we sought to better understand the relative benefits and risks of cholera chemoprophylaxis for peacekeepers in terms of antibiotic resistance. Using a stochastic model to quantify the potential impact of chemoprophylaxis on importation and transmission of drug-resistant and drug-sensitive Vibrio cholerae , we found that chemoprophylaxis would decrease the probability of cholera importation but would increase the expected number of drug-resistant infections if an importation event were to occur. Despite this potential increase, we found that at least 10 drug-sensitive infections would likely be averted per excess drug-resistant infection under a wide range of assumptions about the underlying prevalence of drug resistance and risk of acquired resistance. Given these findings, policymakers should reconsider whether the potential resistance risks of providing antimicrobial chemoprophylaxis to peacekeepers are sufficient to outweigh the anticipated benefits. Copyright © 2017 American Society for Microbiology.

Considerations around the introduction of a cholera vaccine in Bangladesh.

PubMed

Nelson, Christopher B; Mogasale, Vittal; Bari, Tajul Islam A; Clemens, John D

2014-12-12

Cholera is an endemic and epidemic disease in Bangladesh. On 3 March 2013, a meeting on cholera and cholera vaccination in Bangladesh was convened by the Foundation Mérieux jointly with the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR, B). The purpose of the meeting was to discuss the investment case for cholera vaccination as a complimentary control and prevention strategy. The performance of a new low cost oral cholera vaccine, Shanchol™, used in recent trials in Bangladesh, was also reviewed in the context of a potential large-scale public-sector vaccination program. Findings showed the oral vaccine to be highly cost-effective when targeting ages 1-14 y, and cost-effective when targeting ages 1+y, in high-burden/high-risk districts. Other vaccination strategies targeting urban slums and rural areas without improved water were found to be cost-effective. Regardless of cost-effectiveness (value), the budget impact (affordability) will be an important determinant of which target population and vaccination strategy is selected. Most importantly, adequate vaccine supply for the proposed vaccination programs must be addressed in the context of global efforts to establish a cholera vaccine stockpile and supply other control and prevention efforts. Copyright © 2014. Published by Elsevier Ltd.. All rights reserved.

Large cholera outbreak in Brong Ahafo Region, Ghana.

PubMed

Noora, Charles Lwanga; Issah, Kofi; Kenu, Ernest; Bachan, Emmanuel George; Nuoh, Robert Domo; Nyarko, Kofi Mensah; Appiah, Paulina; Letsa, Timothy

2017-08-10

A nationwide outbreak of Vibrio cholerae occurred in Ghana in 2014 with Accra, the nation's capital as the epi-center. The outbreak spread to the Brong Ahafo Region (BAR) which is geographically located in the middle of the country. In this region a review of data collected during the outbreak was carried out and analyzed descriptively to determine the hot spots and make recommendations for effective response to future outbreaks. A review of patient records and line lists of cases of cholera reported in all hospitals during the period of the outbreak (July-December 2014) was conducted. Hospitals used IDSR (Integrated Disease Surveillance and Response system) standard case definitions to detect and report cases for management. The GPS coordinates of all districts and health facilities were collected and utilized in the construction of spot maps. We also obtained populations (denominators) from the BAR Health surveillance unit of the Ghana Health Service. All the data thus collected was analyzed descriptively and expressed as frequencies and rates. A total of 1035 cases were reported, 550 (53.4%) were males and the rest females. Their ages ranged from 1 to 95 years; (mean age of 28.2 ± 19.6 years). The most affected (23.5%) was the 20-29 year old age group. On the 30th July, 2014, a 26 year old male (recorded as the index case of the cholera outbreak in the Brong Ahafo region) with a history of travel from Accra reported to the Nkoranza district hospital with a history of symptoms suggestive of cholera. The reporting of cholera cases reached their peak (17.3%) in week 15 of the outbreak (this lasted 25 weeks). An overall attack rate of 71/100,000 population, and a case fatality rate of 2.4% was recorded in the region. Asutifi South district however recorded a case fatality of 9.1%, the highest amongst all the districts which recorded outbreaks. The majority of the cases reported in the region were from Atebubu-Amanten, Sene West, Pru, and Asunafo North

The increased severity in patients presenting to hospital with diarrhea in Dhaka, Bangladesh since the emergence of the hybrid strain of Vibrio cholerae O1 is not unique to cholera patients.

PubMed

Chowdhury, Fahima; Kuchta, Alison; Khan, Ashraful Islam; Faruque, A S G; Calderwood, Stephen B; Ryan, Edward T; Qadri, Firdausi

2015-11-01

A hybrid strain of Vibrio cholerae O1 El Tor that expresses a classical cholera toxin (CT) emerged in 2001. This hybrid variant rapidly replaced the previous El Tor strain around the world. The global emergence of this variant coincided with anecdotal reports that cholera patients were presenting with more severe dehydration and disease in many locations. A comparison was made of the severity of disease before and after the emergence of the hybrid strain in cholera patients attending an icddr,b hospital in Dhaka, Bangladesh. It was found that cholera patients presented with more severe dehydration and severe disease in the later period. However, this was also true for all non-cholera patients as well. In addition, in sub-analyses of patients who presented with rotavirus and enterotoxigenic Escherichia coli (ETEC), similar results were found. Comparing the two periods for differences in patient characteristics, nutritional status, vaccination status, and income, no plausible cause for patients presenting with more severe disease was identified in the later period. As a shift in severity for both cholera and non-cholera was observed, these results indicate that the altered El Tor strain cannot fully explain the difference in cholera severity before and after 2001. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

[Cholera in 1831. Challenges for science and the federal government].

PubMed

Stamm-Kuhlmann, T

1989-01-01

The peak of the first great cholera pandemic in 1831 fomented the controversy among contagionists and non-contagionists. In the following year the public debate centered around the correct interpretation of the recent experiences with cholera. The central government of the bureaucratic-absolutist monarchy in Prussia adhered to a firmly contagionist interpretation of the disease and reacted accordingly. Local authorities in Königsberg and Berlin and the bourgeoisie in the merchant city of Danzig, however, stressed the destructive consequences of the cordon system. They considered the results of an interruption in trade and industry to be worse than the damage inflicted by the epidemic. The summer of 1831 demonstrated that cholera could not be stopped by the cordons, but the King's medical advisors nevertheless remained contagionists. Non-contagionists put forward several hypotheses to explain the origin and the spreading of cholera, mainly "miasma" theory and the Hippocratic paradigm of "epidemic constitution". The correlation between poverty and disease, however, was widely noticed. Physicians in the city of Bremen pointed to the necessity of sanitary precautions to be taken in cholera-free periods. On the other hand, many "honest" citizens believed that individuals with a "dissolute" conduct of life were more at risk to contract cholera than others. Instead of costly sanitary policies, the well-to-do classes preferred to identify the defense against cholera with the segregation of unwelcome elements of society. The article is based on hitherto unpublished sources from the former Prussian State Archives at Merseburg, GDR, and the State Archive of the Hanseatic City of Bremen.

Cold exposure affects carbohydrates and lipid metabolism, and induces Hog1p phosphorylation in Dekkera bruxellensis strain CBS 2499.

PubMed

Galafassi, Silvia; Toscano, Marco; Vigentini, Ileana; Zambelli, Paolo; Simonetti, Paolo; Foschino, Roberto; Compagno, Concetta

2015-05-01

Dekkera bruxellensis is a yeast known to affect the quality of wine and beer. This species, due to its high ethanol and acid tolerance, has been reported also to compete with Saccharomyces cerevisiae in distilleries producing fuel ethanol. In order to understand how this species responds when exposed to low temperatures, some mechanisms like synthesis and accumulation of intracellular metabolites, changes in lipid composition and activation of the HOG-MAPK pathway were investigated in the genome sequenced strain CBS 2499. We show that cold stress caused intracellular accumulation of glycogen, but did not induce accumulation of trehalose and glycerol. The cellular fatty acid composition changed after the temperature downshift, and a significant increase of palmitoleic acid was observed. RT-PCR analysis revealed that OLE1 encoding for Δ9-fatty acid desaturase was up-regulated, whereas TPS1 and INO1 didn't show changes in their expression. In D. bruxellensis Hog1p was activated by phosphorylation, as described in S. cerevisiae, highlighting a conserved role of the HOG-MAP kinase signaling pathway in cold stress response.

Identification of burden hotspots and risk factors for cholera in India: An observational study

PubMed Central

Sen Gupta, Sanjukta; Arora, Nisha; Khasnobis, Pradeep; Venkatesh, Srinivas; Sur, Dipika; Nair, Gopinath B.; Sack, David A.; Ganguly, Nirmal K.

2017-01-01

Background Even though cholera has existed for centuries and many parts of the country have sporadic, endemic and epidemic cholera, it is still an under-recognized health problem in India. A Cholera Expert Group in the country was established to gather evidence and to prepare a road map for control of cholera in India. This paper identifies cholera burden hotspots and factors associated with an increased risk of the disease. Methodology/Principle findings We acquired district level data on cholera case reports of 2010–2015 from the Integrated Disease Surveillance Program. Socioeconomic characteristics and coverage of water and sanitation was obtained from the 2011 census. Spatial analysis was performed to identify cholera hotspots, and a zero-inflated Poisson regression was employed to identify the factors associated with cholera and predicted case count in the district. 27,615 cholera cases were reported during the 6-year period. Twenty-four of 36 states of India reported cholera during these years, and 13 states were classified as endemic. Of 641 districts, 78 districts in 15 states were identified as “hotspots” based on the reported cases. On the other hand, 111 districts in nine states were identified as “hotspots” from model-based predicted number of cases. The risk for cholera in a district was negatively associated with the coverage of literate persons, households using treated water source and owning mobile telephone, and positively associated with the coverage of poor sanitation and drainage conditions and urbanization level in the district. Conclusions/Significance The study reaffirms that cholera continues to occur throughout a large part of India and identifies the burden hotspots and risk factors. Policymakers may use the findings of the article to develop a roadmap for prevention and control of cholera in India. PMID:28837645

An Optimal Cost Effectiveness Study on Zimbabwe Cholera Seasonal Data from 2008–2011

PubMed Central

Sardar, Tridip; Mukhopadhyay, Soumalya; Bhowmick, Amiya Ranjan; Chattopadhyay, Joydev

2013-01-01

Incidence of cholera outbreak is a serious issue in underdeveloped and developing countries. In Zimbabwe, after the massive outbreak in 2008–09, cholera cases and deaths are reported every year from some provinces. Substantial number of reported cholera cases in some provinces during and after the epidemic in 2008–09 indicates a plausible presence of seasonality in cholera incidence in those regions. We formulate a compartmental mathematical model with periodic slow-fast transmission rate to study such recurrent occurrences and fitted the model to cumulative cholera cases and deaths for different provinces of Zimbabwe from the beginning of cholera outbreak in 2008–09 to June 2011. Daily and weekly reported cholera incidence data were collected from Zimbabwe epidemiological bulletin, Zimbabwe Daily cholera updates and Office for the Coordination of Humanitarian Affairs Zimbabwe (OCHA, Zimbabwe). For each province, the basic reproduction number () in periodic environment is estimated. To the best of our knowledge, this is probably a pioneering attempt to estimate in periodic environment using real-life data set of cholera epidemic for Zimbabwe. Our estimates of agree with the previous estimate for some provinces but differ significantly for Bulawayo, Mashonaland West, Manicaland, Matabeleland South and Matabeleland North. Seasonal trend in cholera incidence is observed in Harare, Mashonaland West, Mashonaland East, Manicaland and Matabeleland South. Our result suggests that, slow transmission is a dominating factor for cholera transmission in most of these provinces. Our model projects cholera cases and cholera deaths during the end of the epidemic in 2008–09 to January 1, 2012. We also determine an optimal cost-effective control strategy among the four government undertaken interventions namely promoting hand-hygiene & clean water distribution, vaccination, treatment and sanitation for each province. PMID:24312540

Identification of burden hotspots and risk factors for cholera in India: An observational study.

PubMed

Ali, Mohammad; Sen Gupta, Sanjukta; Arora, Nisha; Khasnobis, Pradeep; Venkatesh, Srinivas; Sur, Dipika; Nair, Gopinath B; Sack, David A; Ganguly, Nirmal K

2017-01-01

Even though cholera has existed for centuries and many parts of the country have sporadic, endemic and epidemic cholera, it is still an under-recognized health problem in India. A Cholera Expert Group in the country was established to gather evidence and to prepare a road map for control of cholera in India. This paper identifies cholera burden hotspots and factors associated with an increased risk of the disease. We acquired district level data on cholera case reports of 2010-2015 from the Integrated Disease Surveillance Program. Socioeconomic characteristics and coverage of water and sanitation was obtained from the 2011 census. Spatial analysis was performed to identify cholera hotspots, and a zero-inflated Poisson regression was employed to identify the factors associated with cholera and predicted case count in the district. 27,615 cholera cases were reported during the 6-year period. Twenty-four of 36 states of India reported cholera during these years, and 13 states were classified as endemic. Of 641 districts, 78 districts in 15 states were identified as "hotspots" based on the reported cases. On the other hand, 111 districts in nine states were identified as "hotspots" from model-based predicted number of cases. The risk for cholera in a district was negatively associated with the coverage of literate persons, households using treated water source and owning mobile telephone, and positively associated with the coverage of poor sanitation and drainage conditions and urbanization level in the district. The study reaffirms that cholera continues to occur throughout a large part of India and identifies the burden hotspots and risk factors. Policymakers may use the findings of the article to develop a roadmap for prevention and control of cholera in India.

Continuous Human Action Recognition Using Depth-MHI-HOG and a Spotter Model

PubMed Central

Eum, Hyukmin; Yoon, Changyong; Lee, Heejin; Park, Mignon

2015-01-01

In this paper, we propose a new method for spotting and recognizing continuous human actions using a vision sensor. The method is comprised of depth-MHI-HOG (DMH), action modeling, action spotting, and recognition. First, to effectively separate the foreground from background, we propose a method called DMH. It includes a standard structure for segmenting images and extracting features by using depth information, MHI, and HOG. Second, action modeling is performed to model various actions using extracted features. The modeling of actions is performed by creating sequences of actions through k-means clustering; these sequences constitute HMM input. Third, a method of action spotting is proposed to filter meaningless actions from continuous actions and to identify precise start and end points of actions. By employing the spotter model, the proposed method improves action recognition performance. Finally, the proposed method recognizes actions based on start and end points. We evaluate recognition performance by employing the proposed method to obtain and compare probabilities by applying input sequences in action models and the spotter model. Through various experiments, we demonstrate that the proposed method is efficient for recognizing continuous human actions in real environments. PMID:25742172

SEASONAL EMISSIONS OF AMMONIA AND METHANE FROM A HOG WASTE LAGOON WITH BIOACTIVE COVER

EPA Science Inventory

The paper discusses the use of plane-integrated (PI) open-path Fourier transform infrared spectrometry (OP-FTIR) to measure the flux of ammonia and methane from a hog waste lagoon before and after the installation of a bioactive cover. A computed tomography algorithm using a smoo...

PaxVax CVD 103-HgR single-dose live oral cholera vaccine.

PubMed

Levine, Myron M; Chen, Wilbur H; Kaper, James B; Lock, Michael; Danzig, Lisa; Gurwith, Marc

2017-03-01

Cholera remains a problem in developing countries and a risk for travelers. Hypochlorhydria, blood group O, cardiac and renal disease increase the risk of developing cholera gravis. Oral vaccines containing inactivated Vibrio cholerae and requiring two doses are available in some countries. No cholera vaccine had been available for U.S. travelers for decades until 2016 when CVD 103-HgR (VAXCHORA™), an oral live attenuated vaccine, was licensed by the U.S. FDA. Areas covered: Enduring protection following wild-type cholera provided the rationale to develop a single-dose live oral vaccine. CVD 103-HgR is well-tolerated and protects against cholera caused by V. cholerae O1 of either serotype (Inaba, Ogawa) and biotype (El Tor, Classical). Since 90% vaccine efficacy is evident 10 days post-ingestion of a single dose, CVD 103-HgR can rapidly protect travelers. Vibriocidal antibody seroconversion correlates with protection; >90% of U.S. adult (including elderly) vaccinees seroconvert. The U.S. Public Health Service's Advisory Committee on Immunization Practices recommends CVD 103-HgR for U.S. travelers to areas of ongoing cholera transmission. Expert commentary: Next steps include evaluations in children, post-licensure safety and effectiveness monitoring, diminishing cold chain constraints, optimizing a 'high-dose' formulation for developing countries, and diminishing/eliminating the need for water to administer a dose.

Bactericidal activity of lemon juice and lemon derivatives against Vibrio cholerae.

PubMed

de Castillo, M C; de Allori, C G; de Gutierrez, R C; de Saab, O A; de Fernandez, N P; de Ruiz, C S; Holgado, A P; de Nader, O M

2000-10-01

Food products can be possible vectors of the agent responsible for cholera epidemics, because some of these products allow Vibrio cholerae O1 to develop to concentrations above the dangerous level. This study deals with the behaviour of essential oils, natural and concentrated lemon juice and fresh and dehydrated lemon peel against V. cholerae O1 biotype Eltor serotype Inaba tox+. Our aim was to evaluate whether these products, used at different dilutions, exhibit bactericidal or bacteriostatic activity against the microorganism, when present at concentrations of 10(2), 10(4), 10(6) and 10(8) colony forming units (CFU) ml(-1), and after different exposure times. 10(8) CFU ml(-1) was considered an infectious dose. Concentrated lemon juice and essential oils inhibited V. cholerae completely at all studied dilutions and exposure times. Fresh lemon peel and dehydrated lemon peel partially inhibited growth of V. cholerae. Freshly squeezed lemon juice, diluted to 10(-2), showed complete inhibition of V. cholerae at a concentration of 10(8) CFU ml(-1) after 5 min of exposure time; a dilution of 2 x 10(-3) produced inhibition after 15 min and a dilution of 10(-3) after 30 min. It can be concluded that lemon, a natural product which is easily obtained, acts as a biocide against V. cholerae, and is, therefore, an efficient decontaminant, harmless to humans.

A five-year study on the epidemiological approaches to cholera in Iran.

PubMed

Mafi, Moharam; Goya, Mohammad Mahdi; Hajia, Massoud

2016-01-01

Cholera is considered a key indicator of social development but still is reported in various cities of Iran. The present study aimed to analyze the available information regarding cholera outbreaks since 2010 in Iran. All cases reported to the Center for Disease Control and Prevention of Ministry of Health and Education who had been confirmed as cholera cases by the Health Reference Laboratory, were entered into this study since 2010. A specific spreadsheet was designed to ensure the safe keeping of the patient records. A total of 1522 patients were clinically diagnosed as cholera with laboratory confirmation over the study period. Cholera was detected in 26 Provinces and 115 cities during this period. Mean age of the patients was 35.1±17, both the Inaba and Ogawa strains were isolated. The highest mortality and the morbidity rate was 1.98% in 2013. The most cholera prevalent provinces in order of frequency were Baluchistan, Alborz, Gilan, Golestan and Qom, as well as Tehran. Inaba serotype was the most common cause of mortality and morbidity in 2013. These findings indicate significant outbreaks of cholera in some of the provinces of Iran and warrant appropriate treatment and preventive measures.

Chemical ions affect survival of avian cholera organisms in pondwater

USGS Publications Warehouse

Price, J.I.; Yandell, B.S.; Porter, W.P.

1992-01-01

Avian cholera (Pasteurella multocida) is a major disease of wild waterfowl, but its epizootiology remains little understood. Consequently, we examined whether chemical ions affected survival of avian cholera organisms in water collected from the Nebraska Rainwater Basin where avian cholera is enzootic. We tested the response of P. multocida to ammonium (NH4), calcium (Ca), magnesium (Mg), nitrate (NO3), and ortho-phosphate (PO4) ions individually and in combination using a fractional factorial design divided into 4 blocks. High concentrations of Ca and Mg, singly or in combination, increased survival of P. multocida organisms (P < 0.001). We developed a survival index to predict whether or not specific ponds could be "problem" or "nonproblem" avian cholera sites based on concentrations of these ions in the water.

Small-molecule inhibitors of toxT expression in Vibrio cholerae.

PubMed

Anthouard, Rebecca; DiRita, Victor J

2013-08-06

Vibrio cholerae, a Gram-negative bacterium, infects humans and causes cholera, a severe disease characterized by vomiting and diarrhea. These symptoms are primarily caused by cholera toxin (CT), whose production by V. cholerae is tightly regulated by the virulence cascade. In this study, we designed and carried out a high-throughput chemical genetic screen to identify inhibitors of the virulence cascade. We identified three compounds, which we named toxtazin A and toxtazin B and B', representing two novel classes of toxT transcription inhibitors. All three compounds reduce production of both CT and the toxin-coregulated pilus (TCP), an important colonization factor. We present evidence that toxtazin A works at the level of the toxT promoter and that toxtazins B and B' work at the level of the tcpP promoter. Treatment with toxtazin B results in a 100-fold reduction in colonization in an infant mouse model of infection, though toxtazin A did not reduce colonization at the concentrations tested. These results add to the growing body of literature indicating that small-molecule inhibitors of virulence genes could be developed to treat infections, as alternatives to antibiotics become increasingly needed. V. cholerae caused more than 580,000 infections worldwide in 2011 alone (WHO, Wkly. Epidemiol. Rec. 87:289-304, 2012). Cholera is treated with an oral rehydration therapy consisting of water, glucose, and electrolytes. However, as V. cholerae is transmitted via contaminated water, treatment can be difficult for communities whose water source is contaminated. In this study, we address the need for new therapeutic approaches by targeting the production of the main virulence factor, cholera toxin (CT). The high-throughput screen presented here led to the identification of two novel classes of inhibitors of the virulence cascade in V. cholerae, toxtazin A and toxtazins B and B'. We demonstrate that (i) small-molecule inhibitors of virulence gene production can be

[Four cholera epidemics in nineteenth-century London].

PubMed

Tynkkynen, K

1995-01-01

Asiatic cholera originated in India and spread to Europe in the early years of the nineteenth-century. In Britain the first cases were diagnosed late in 1831. The epidemic, reached London in February 1832. The authorities were poorly prepared for the invasion of a new epidemic and the doctors disagreed bitterly on the measures to be taken. There was little co-operation between the authorities, and the fact that the urban poor mistrusted the medical profession did not improve the situation. All this resulted in several cholera riots. These riots were not, however, as violent as those in several other cities in Europe. The 1832-33 cholera epidemic claimed 4,000 to 7,000 victims in London. It seems probable that several isolated cases of cholera occurred in London in 1852. It was not, however, until September 1853 that it was officially announced by the British authorities that a cholera epidemic was claiming victims not only in London but also in other parts of the country. During this epidemic numerous Londoners lodged complaints against nuisances in the metropolis. Yet, in most cases, the fines imposed on offenders were rather slight, since the authorities were extremely reluctant to interfere with anyone's trade or business. It was during this epidemic that John Snow, a London doctor, succeeded in tracing the epidemic to a single water pump on Broad Street in the Golden Square area. Snow did not, however, succeed in convincing the majority of his colleagues regarding the erroneous nature of the miasma theory during the epidemic of 1853/54, which cost the lives of some 12,000 people in the city area....

Single-dose Live Oral Cholera Vaccine CVD 103-HgR Protects Against Human Experimental Infection With Vibrio cholerae O1 El Tor.

PubMed

Chen, Wilbur H; Cohen, Mitchell B; Kirkpatrick, Beth D; Brady, Rebecca C; Galloway, David; Gurwith, Marc; Hall, Robert H; Kessler, Robert A; Lock, Michael; Haney, Douglas; Lyon, Caroline E; Pasetti, Marcela F; Simon, Jakub K; Szabo, Flora; Tennant, Sharon; Levine, Myron M

2016-06-01

No licensed cholera vaccine is presently available in the United States. Cholera vaccines available in other countries require 2 spaced doses. A single-dose cholera vaccine that can rapidly protect short-notice travelers to high-risk areas and help control explosive outbreaks where logistics render 2-dose immunization regimens impractical would be a major advance.PXVX0200, based on live attenuated Vibrio cholerae O1 classical Inaba vaccine strain CVD 103-HgR, elicits seroconversion of vibriocidal antibodies (a correlate of protection) within 10 days of a single oral dose. We investigated the protection conferred by this vaccine in a human cholera challenge model. Consenting healthy adult volunteers, 18-45 years old, were randomly allocated 1:1 to receive 1 oral dose of vaccine (approximately 5 × 10(8) colony-forming units [CFU]) or placebo in double-blind fashion. Volunteers ingested approximately 1 × 10(5) CFU of wild-type V. cholerae O1 El Tor Inaba strain N16961 10 days or 3 months after vaccination and were observed on an inpatient research ward for stool output measurement and management of hydration. The vaccine was well tolerated, with no difference in adverse event frequency among 95 vaccinees vs 102 placebo recipients. The primary endpoint, moderate (≥3.0 L) to severe (≥5.0 L) diarrheal purge, occurred in 39 of 66 (59.1%) placebo controls but only 2 of 35 (5.7%) vaccinees at 10 days (vaccine efficacy, 90.3%; P < .0001) and 4 of 33 (12.1%) vaccinees at 3 months (vaccine efficacy, 79.5%; P < .0001). The significant vaccine efficacy documented 10 days and 3 months after 1 oral dose of PXVX0200 supports further development as a single-dose cholera vaccine. NCT01895855. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Biological characterization of v. Cholerae-specific bacteriophages isolated from water sources in Georgia.

PubMed

Elbakidze, T; Kokashvili, T; Janelidze, N; Porchkhidze, K; Koberidze, T; Tediashvili, M

2015-03-01

Vibrio cholerae, a widely spread bacterium in various marine, fresh, and brackish water environments, can cause a devastating diarrheal disease - cholera and also mild forms of gastroenteritis. Bacterial viruses are natural controllers of bacterial population density in water systems. The goal of this study was to isolate and characterize V. cholerae-specific bacteriophages occurring in the Georgian coastal zone of the Black Sea and inland water reservoirs in the eastern part of Georgia. During 2006-2009, 71 phages lytic to V. cholerae were collected from these aquatic environments. The phage isolation rate was varying from 8% to 15%, depending on the sampling season and site, and the abundance of host bacteria. The majority of phages specific to V. cholerae were collected from freshwater sources. The phage isolation showed seasonal character covering warm period -from April to September. Based on basic characteristics of primary phage isolates (lytic spectrum, virion morphology and DNA restriction profiles) 23 V. cholerae -specific phages were selected for series of consecutive screenings. Comparatively wide spectrum of lytic activity was revealed in case of 14 phages specific to V. cholerae O1, and one phage - VchBS3, active against non-O1 V. cholerae. Three phages active against V. cholerae non-O1 and six V. cholerae O1 -specific phages have been studied in detail for a number of biological features (stability in different solutions, temperature-, pH- and UV- sensitivity, influence of high ionic strength etc.), considered to be additional important characteristics for selection of phages with therapeutic potential.

[Mexican phenotype and genotype Vibrio cholerae 01].

PubMed

Giono, S; Gutiérrez Cogno, L; Rodríguez Angeles, G; del Rio Zolezzi, A; Valdespino González, J L; Sepúlveda Amor, J

1995-01-01

This paper presents the phenotypical and genotypical characterization of 26922 Vibrio cholerae 01 strains isolated in Mexico from 1991 to 1993. All strains isolated were El Tor biovar. Strains were sensitive to antibiotics excluding furazolidone, streptomycin and sulfisoxasole to which we found resistance in 97% and we are using this characteristic as epidemiological markers. We detected a marked change in frequency of Inaba serotype from 1991, when it was dominant, with 99.5%, until 1992 when Ogawa serotype turned to be dominant with 95% of isolates. All Vibrio cholerae 01 strains, except one Ogawa strain, were to igenic, and V. choleraeno 01 were not toxigenic by ELISA, PCR and cell culture tests. Dominant ribotype was 5, but we found some strains with 6a pattern and two with ribotype 12. We are searching for ribotype 2 among hemolytic strains in order to learn if there is any relation to Gulf Coast strains prevalent in the USA, but until now we have not found any V. cholerae ribotype 2 in our isolates. Even if rapid tests are recommended for immediate diagnosis of cholera, it is necessary to continue bacterial isolation in order to have strains for phenotyping and genotyping studies that may support epidemiological analysis.

Cholera Toxin B: One Subunit with Many Pharmaceutical Applications

PubMed Central

Baldauf, Keegan J.; Royal, Joshua M.; Hamorsky, Krystal Teasley; Matoba, Nobuyuki

2015-01-01

Cholera, a waterborne acute diarrheal disease caused by Vibrio cholerae, remains prevalent in underdeveloped countries and is a serious health threat to those living in unsanitary conditions. The major virulence factor is cholera toxin (CT), which consists of two subunits: the A subunit (CTA) and the B subunit (CTB). CTB is a 55 kD homopentameric, non-toxic protein binding to the GM1 ganglioside on mammalian cells with high affinity. Currently, recombinantly produced CTB is used as a component of an internationally licensed oral cholera vaccine, as the protein induces potent humoral immunity that can neutralize CT in the gut. Additionally, recent studies have revealed that CTB administration leads to the induction of anti-inflammatory mechanisms in vivo. This review will cover the potential of CTB as an immunomodulatory and anti-inflammatory agent. We will also summarize various recombinant expression systems available for recombinant CTB bioproduction. PMID:25802972

Cholera in Haiti: Reproductive numbers and vaccination coverage estimates

NASA Astrophysics Data System (ADS)

Mukandavire, Zindoga; Smith, David L.; Morris, J. Glenn, Jr.

2013-01-01

Cholera reappeared in Haiti in October, 2010 after decades of absence. Cases were first detected in Artibonite region and in the ensuing months the disease spread to every department in the country. The rate of increase in the number of cases at the start of epidemics provides valuable information about the basic reproductive number (). Quantitative analysis of such data gives useful information for planning and evaluating disease control interventions, including vaccination. Using a mathematical model, we fitted data on the cumulative number of reported hospitalized cholera cases in Haiti. varied by department, ranging from 1.06 to 2.63. At a national level, 46% vaccination coverage would result in an () <1, which would suppress transmission. In the current debate on the use of cholera vaccines in endemic and non-endemic regions, our results suggest that moderate cholera vaccine coverage would be an important element of disease control in Haiti.

Epidemic cholera in Latin America, 1991-1993: implications of case definitions used for public health surveillance.

PubMed

Koo, D; Traverso, H; Libel, M; Drasbek, C; Tauxe, R; Brandling-Bennett, D

1996-06-01

This report presents the various cholera case definitions used by the affected countries of Latin America, shows the numbers of cholera cases and deaths attributable to cholera (as reported by Latin American countries to PAHO through 1993), and describes some regional trends in cholera incidence. The information about how cholera cases were defined was obtained from an October 1993 PAHO questionnaire. In all, 948429 cholera cases were reported to PAHO by affected Latin American countries from January 1991 through December 1993, the highest annual incidences being registered in Peru (1991 and 1992) and Guatemala (1993). The case-fatality rate over the three-year period, and also in 1993, was 0.8%. A general downward trend in the incidence of cholera was observed in most South American countries, while the incidence increased in most Central American countries. A good deal of variation was noted in the definitions used for reporting cholera cases, hospitalized cholera cases, and cholera-attributable deaths. Because of these variations, broad intercountry comparisons (including disease burden calculations and care quality assessments based on case-fatality rates) are difficult to make, and even reported trends within a single country need to be evaluated with care. The situation is likely to be complicated in the future by the arrival of V. cholerae O139 in Latin America, creating a need to distinguish between it and the prevailing O1 strain. For purposes of simplicity, wide acceptance, and broad dissemination of case data, the following definitions are recommended: Confirmed case of O1 cholera: laboratory-confirmed infection with toxigenic V. cholerae O1 in any person who has diarrhea. Confirmed case of O139 cholera: laboratory-confirmed infection with toxigenic V. cholerae O139 in any person who has diarrhea. Clinical case of cholera: acute watery diarrhea in a person over 5 years old who is seeking treatment. Death attributable to cholera: death within one week of

Estimating the reproductive numbers for the 2008–2009 cholera outbreaks in Zimbabwe

PubMed Central

Mukandavire, Zindoga; Liao, Shu; Wang, Jin; Gaff, Holly; Smith, David L.; Morris, J. Glenn

2011-01-01

Cholera remains an important global cause of morbidity and mortality, capable of causing periodic epidemic disease. Beginning in August 2008, a major cholera epidemic occurred in Zimbabwe, with 98,585 reported cases and 4,287 deaths. The dynamics of such outbreaks, particularly in nonestuarine regions, are not well understood. We explored the utility of mathematical models in understanding transmission dynamics of cholera and in assessing the magnitude of interventions necessary to control epidemic disease. Weekly data on reported cholera cases were obtained from the Zimbabwe Ministry of Health and Child Welfare (MoHCW) for the period from November 13, 2008 to July 31, 2009. A mathematical model was formulated and fitted to cumulative cholera cases to estimate the basic reproductive numbers R0 and the partial reproductive numbers from all 10 provinces for the 2008–2009 Zimbabwe cholera epidemic. Estimated basic reproductive numbers were highly heterogeneous, ranging from a low value of just above unity to 2.72. Partial reproductive numbers were also highly heterogeneous, suggesting that the transmission routes varied by province; human-to-human transmission accounted for 41–95% of all transmission. Our models suggest that the underlying patterns of cholera transmission varied widely from province to province, with a corresponding variation in the amenability of outbreaks in different provinces to control measures such as immunization. These data underscore the heterogeneity of cholera transmission dynamics, potentially linked to differences in environment, socio-economic conditions, and cultural practices. The lack of traditional estuarine reservoirs combined with these estimates of R0 suggest that mass vaccination against cholera deployed strategically in Zimbabwe and surrounding regions could prevent future cholera epidemics and eventually eliminate cholera from the region. PMID:21518855

Pulmonary cholera due to infection with a non-O1 Vibrio cholerae strain.

PubMed

Shannon, Jack D; Kimbrough, Robert C

2006-09-01

We present 2 cases of primary pulmonary non-O1 Vibrio cholerae infection. We believe that these are the first documented cases of primary pulmonary infection due to this organism from a freshwater source.

Genomic Epidemiology of Vibrio cholerae O1 Associated with Floods, Pakistan, 2010

PubMed Central

Shah, Muhammad Ali; Mutreja, Ankur; Thomson, Nicholas; Baker, Stephen; Parkhill, Julian; Dougan, Gordon; Bokhari, Habib

2014-01-01

In August 2010, Pakistan experienced major floods and a subsequent cholera epidemic. To clarify the population dynamics and transmission of Vibrio cholerae in Pakistan, we sequenced the genomes of all V. cholerae O1 El Tor isolates and compared the sequences to a global collection of 146 V. cholerae strains. Within the global phylogeny, all isolates from Pakistan formed 2 new subclades (PSC-1 and PSC-2), lying in the third transmission wave of the seventh-pandemic lineage that could be distinguished by signature deletions and their antimicrobial susceptibilities. Geographically, PSC-1 isolates originated from the coast, whereas PSC-2 isolates originated from inland areas flooded by the Indus River. Single-nucleotide polymorphism accumulation analysis correlated river flow direction with the spread of PSC-2. We found at least 2 sources of cholera in Pakistan during the 2010 epidemic and illustrate the value of a global genomic data bank in contextualizing cholera outbreaks. PMID:24378019

Genomic epidemiology of Vibrio cholerae O1 associated with floods, Pakistan, 2010.

PubMed

Shah, Muhammad Ali; Mutreja, Ankur; Thomson, Nicholas; Baker, Stephen; Parkhill, Julian; Dougan, Gordon; Bokhari, Habib; Wren, Brendan W

2014-01-01

In August 2010, Pakistan experienced major floods and a subsequent cholera epidemic. To clarify the population dynamics and transmission of Vibrio cholerae in Pakistan, we sequenced the genomes of all V. cholerae O1 El Tor isolates and compared the sequences to a global collection of 146 V. cholerae strains. Within the global phylogeny, all isolates from Pakistan formed 2 new subclades (PSC-1 and PSC-2), lying in the third transmission wave of the seventh-pandemic lineage that could be distinguished by signature deletions and their antimicrobial susceptibilities. Geographically, PSC-1 isolates originated from the coast, whereas PSC-2 isolates originated from inland areas flooded by the Indus River. Single-nucleotide polymorphism accumulation analysis correlated river flow direction with the spread of PSC-2. We found at least 2 sources of cholera in Pakistan during the 2010 epidemic and illustrate the value of a global genomic data bank in contextualizing cholera outbreaks.

Persistence of Escherichia coli and Salmonella in surface soil following application of liquid hog manure for production of pickling cucumbers.

PubMed

Côté, Caroline; Quessy, Sylvain

2005-05-01

Liquid hog manure is routinely applied to farm land as a crop fertilizer. However, this practice raises food safety concerns, especially when manure is used on fruit and vegetable crops. The objectives of this project were to evaluate the persistence of Escherichia coli and Salmonella in surface soil after application of liquid hog manure to fields where pickling cucumbers were grown and to verify the microbiological quality of harvested cucumbers. Mineral fertilizers were replaced by liquid hog manure at various ratios in the production of pickling cucumbers in a 3-year field study. The experimental design was a randomized complete block comprising four replicates in sandy loam (years 1, 2, and 3) and loamy sand (year 3). Soil samples were taken at a depth of 20 cm every 2 weeks after June application of organic and inorganic fertilizers. Vegetable samples were also taken at harvest time. Liquid hog manure, soil, and vegetable (washed and unwashed) samples were analyzed for the presence of Salmonella and E. coli. An exponential decrease of E. coli populations was observed in surface soil after the application of manure. The estimated average time required to reach undetectable concentrations of E. coli in sandy loam varied from 56 to 70 days, whereas the absence of E. coli was estimated at 77 days in loamy sand. The maximal Salmonella persistence in soil was 54 days. E. coli and Salmonella were not detected in any vegetable samples.

Cholera Illness and Symptoms

MedlinePlus

... food will lead to additional infections. Dispose of human waste appropriately to prevent the spread of cholera. Persons ... contaminated and properly disposing of contaminated items and human waste. Person washing hands over a bucket of water. ...

On the probability of extinction of the Haiti cholera epidemic

NASA Astrophysics Data System (ADS)

Bertuzzo, Enrico; Finger, Flavio; Mari, Lorenzo; Gatto, Marino; Rinaldo, Andrea

2014-05-01

Nearly 3 years after its appearance in Haiti, cholera has already exacted more than 8,200 deaths and 670,000 reported cases and it is feared to become endemic. However, no clear evidence of a stable environmental reservoir of pathogenic Vibrio cholerae, the infective agent of the disease, has emerged so far, suggesting that the transmission cycle of the disease is being maintained by bacteria freshly shed by infected individuals. Thus in principle cholera could possibly be eradicated from Haiti. Here, we develop a framework for the estimation of the probability of extinction of the epidemic based on current epidemiological dynamics and health-care practice. Cholera spreading is modelled by an individual-based spatially-explicit stochastic model that accounts for the dynamics of susceptible, infected and recovered individuals hosted in different local communities connected through hydrologic and human mobility networks. Our results indicate that the probability that the epidemic goes extinct before the end of 2016 is of the order of 1%. This low probability of extinction highlights the need for more targeted and effective interventions to possibly stop cholera in Haiti.

Vibriosis, not cholera: toxigenic Vibrio cholerae non-O1, non-O139 infections in the United States, 1984-2014.

PubMed

Crowe, S J; Newton, A E; Gould, L H; Parsons, M B; Stroika, S; Bopp, C A; Freeman, M; Greene, K; Mahon, B E

2016-11-01

Toxigenic strains of Vibrio cholerae serogroups O1 and O139 have caused cholera epidemics, but other serogroups - such as O75 or O141 - can also produce cholera toxin and cause severe watery diarrhoea similar to cholera. We describe 31 years of surveillance for toxigenic non-O1, non-O139 infections in the United States and map these infections to the state where the exposure probably originated. While serogroups O75 and O141 are closely related pathogens, they differ in how and where they infect people. Oysters were the main vehicle for O75 infection. The vehicles for O141 infection include oysters, clams, and freshwater in lakes and rivers. The patients infected with serogroup O75 who had food traceback information available ate raw oysters from Florida. Patients infected with O141 ate oysters from Florida and clams from New Jersey, and those who only reported being exposed to freshwater were exposed in Arizona, Michigan, Missouri, and Texas. Improving the safety of oysters, specifically, should help prevent future illnesses from these toxigenic strains and similar pathogenic Vibrio species. Post-harvest processing of raw oysters, such as individual quick freezing, heat-cool pasteurization, and high hydrostatic pressurization, should be considered.

A water marker monitored by satellites to predict seasonal endemic cholera.

PubMed

Jutla, Antarpreet; Akanda, Ali Shafqat; Huq, Anwar; Faruque, Abu Syed Golam; Colwell, Rita; Islam, Shafiqul

2013-01-01

The ability to predict an occurrence of cholera, a water-related disease, offers a significant public health advantage. Satellite based estimates of chlorophyll, a surrogate for plankton abundance, have been linked to cholera incidence. However, cholera bacteria can survive under a variety of coastal ecological conditions, thus constraining the predictive ability of the chlorophyll, since it provides only an estimate of greenness of seawater. Here, a new remote sensing based index is proposed: Satellite Water Marker (SWM), which estimates condition of coastal water, based on observed variability in the difference between blue (412 nm) and green (555 nm) wavelengths that can be related to seasonal cholera incidence. The index is bounded between physically separable wavelengths for relatively clear (blue) and turbid (green) water. Using SWM, prediction of cholera with reasonable accuracy, with at least two month in advance, can potentially be achieved in the endemic coastal regions.

Increased antibiotic resistance exhibited by the biofilm of Vibrio cholerae O139.

PubMed

Gupta, Preeti; Mankere, Bharti; Chekkoora Keloth, Shami; Tuteja, Urmil; Pandey, Pratibha; Chelvam, Kulanthaivel Thava

2018-04-24

Vibrio cholerae, the aetiological agent of the deadly diarrhoeal disease cholera, is known to form biofilm. The antibiotic susceptibility status of biofilm of V. cholerae O139, an important epidemic strain in India and other countries, has not previously been studied in detail. Antibiotic susceptibility status of planktonic and biofilm cultures of V. cholerae O139 was evaluated by determining MIC, MBC and minimum biofilm eradication concentration (MBEC) values of five different classes of antibiotics using established methods. Effects of antibiotic treatment on planktonic and biofilm cultures were analysed by scanning electron microscopy. The virulence of the antibiotic-surviving population (ASP) was evaluated using an infant mouse model. The frequency of spontaneous mutants and inheritability of antibiotic resistance were determined with standard methods. The antibiotic resistance exhibited by biofilm of V. cholerae O139 was found to be significantly higher (P < 0.05) than its planktonic counterpart. The biofilm-associated antibiotic resistance was found to be transient and exclusive to the biofilm culture. The frequency of ASP clones among antibiotic-treated biofilm cultures occurred at a rate of 0.012%-0.95% and these clones were found to retain the virulence and antibiotic resistance of their parent strains. The biofilm of V. cholerae O139 was found to be resistant to different types of antibiotics tested. This unconventional biofilm resistance highlights the hidden danger of antimicrobial escape by V. cholerae, increased risk of cholera transmission and its continued persistence in the environment.

Investigating the role of water in the Diffusion of Cholera using Agent-Based simulation

NASA Astrophysics Data System (ADS)

Augustijn, Ellen-Wien; Doldersum, Tom; Augustijn, Denie

2014-05-01

Traditionally, cholera was considered to be a waterborne disease. Currently we know that many other factors can contribute to the spread of this disease including human mobility and human behavior. However, the hydrological component in cholera diffusion is significant. The interplay between cholera and water includes bacteria (V. cholera) that survive in the aquatic environment, the possibility that run-off water from dumpsites carries the bacteria to surface water (rivers and lakes), and when the bacteria reach streams they can be carried downstream to infect new locations. Modelling is a very important tool to build theory on the interplay between different types of transmission mechanisms that together are responsible for the spread of Cholera. Agent-based simulation models are very suitable to incorporate behavior at individual level and to reproduce emergence. However, it is more difficult to incorporate the hydrological components in this type of model. In this research we present the hydrological component of an Agent-Based Cholera model developed to study a Cholera epidemic in Kumasi (Ghana) in 2005. The model was calibrated on the relative contribution of each community to the distributed pattern of cholera rather than the absolute number of incidences. Analysis of the results shows that water plays an important role in the diffusion of cholera: 75% of the cholera cases were infected via river water that was contaminated by runoff from the dumpsites. To initiate infections upstream, the probability of environment-to-human transmission seemed to be overestimated compared to what may be expected from literature. Scenario analyses show that there is a strong relation between the epidemic curve and the rainfall. Removing dumpsites that are situated close to the river resulted in a strong decrease in the number of cholera cases. Results are sensitive to the scheduling of the daily activities and the survival time of the cholera bacteria.

[Life cycle of Gongylonema mucronatum Seurat, 1916, parasite of the African hedge-hog (author's transl)].

PubMed

Quentin, J C; Seguignes, M

1979-01-01

The Gongylonematid Nematode parasite of the Tunisian hedge-hog has been identified as Gongylonema mucronatum Seurat, 1916. The infective larva has been obtained from Locusta migratoria as intermediate host. The larval characters of this Gongylonema link it to the species G. pulchrum.

Inhibition of the sodium-translocating NADH-ubiquinone oxidoreductase [Na+-NQR] decreases cholera toxin production in Vibrio cholerae O1 at the late exponential growth phase

PubMed Central

Minato, Yusuke; Fassio, Sara R.; Reddekopp, Rylan L.; Häse, Claudia C.

2014-01-01

Two virulence factors produced by Vibrio cholerae, cholera toxin (CT) and toxin-corregulated pilus (TCP), are indispensable for cholera infection. ToxT is the central regulatory protein involved in activation of CT and TCP expression. We previously reported that lack of a respiration-linked sodium-translocating NADH–ubiquinone oxidoreductase (Na+-NQR) significantly increases toxT transcription. In this study, we further characterized this link and found that Na+-NQR affects toxT expression only at the early-log growth phase, whereas lack of Na+-NQR decreases CT production after the mid-log growth phase. Such decreased CT production was independent of toxT and ctxB transcription. Supplementing a respiratory substrate, L-lactate, into the growth media restored CT production in the nqrA-F mutant, suggesting that decreased CT production in the Na+-NQR mutant is dependent on electron transport chain (ETC) activity. This notion was supported by the observations that two chemical inhibitors, a Na+-NQR specific inhibitor 2-n-Heptyl-4-hydroxyquinoline N-oxide (HQNO) and a succinate dehydrogenase (SDH) inhibitor, thenoyltrifluoroacetone (TTFA), strongly inhibited CT production in both classical and El Tor biotype strains of V. cholerae. Accordingly, we propose the main respiratory enzyme of V. cholerae, as a potential drug target to treat cholera because human mitochondria do not contain Na+-NQR orthologs. PMID:24361395

Risk Factors Early in the 2010 Cholera Epidemic, Haiti

PubMed Central

Cartwright, Emily; Loharikar, Anagha; Routh, Janell; Gaines, Joanna; Fouché, Marie-Délivrance Bernadette; Jean-Louis, Reginald; Ayers, Tracy; Johnson, Dawn; Tappero, Jordan W.; Roels, Thierry H.; Archer, W. Roodly; Dahourou, Georges A.; Mintz, Eric; Quick, Robert; Mahon, Barbara E.

2011-01-01

During the early weeks of the cholera outbreak that began in Haiti in October 2010, we conducted a case–control study to identify risk factors. Drinking treated water was strongly protective against illness. Our results highlight the effectiveness of safe water in cholera control. PMID:22099118

Comparative Proteomic Analysis Reveals Activation of Mucosal Innate Immune Signaling Pathways during Cholera

PubMed Central

LaRocque, Regina C.; Uddin, Taher; Krastins, Bryan; Mayo-Smith, Leslie M.; Sarracino, David; Karlsson, Elinor K.; Rahman, Atiqur; Shirin, Tahmina; Bhuiyan, Taufiqur R.; Chowdhury, Fahima; Khan, Ashraful Islam; Ryan, Edward T.; Calderwood, Stephen B.; Qadri, Firdausi

2015-01-01

Vibrio cholerae O1 is a major cause of acute watery diarrhea in over 50 countries. Evidence suggests that V. cholerae O1 may activate inflammatory pathways, and a recent study of a Bangladeshi population showed that variants in innate immune genes play a role in mediating susceptibility to cholera. We analyzed human proteins present in the small intestine of patients infected with V. cholerae O1 to characterize the host response to this pathogen. We collected duodenal biopsy specimens from patients with acute cholera after stabilization and again 30 days after initial presentation. Peptides extracted from biopsy specimens were sequenced and quantified using label-free mass spectrometry and SEQUEST. Twenty-seven host proteins were differentially abundant between the acute and convalescent stages of infection; the majority of these have known roles in innate defense, cytokine production, and apoptosis. Immunostaining confirmed that two proteins, WARS and S100A8, were more abundant in lamina propria cells during the acute stage of cholera. Analysis of the differentially abundant proteins revealed the activation of key regulators of inflammation by the innate immune system, including Toll-like receptor 4, nuclear factor kappa-light-chain-enhancer of activated B cells, mitogen-activated protein kinases, and caspase-dependent inflammasomes. Interleukin-12β (IL-12β) was a regulator of several proteins that were activated during cholera, and we confirmed that IL-12β was produced by lymphocytes recovered from duodenal biopsy specimens of cholera patients. Our study shows that a broad inflammatory response is generated in the gut early after onset of cholera, which may be critical in the development of long-term mucosal immunity against V. cholerae O1. PMID:25561705

Risk Factors for Self-Reported Cholera Within HIV-Affected Households in Rural Haiti

PubMed Central

Cheung, Hoi Ching; Meiselbach, Mark K; Jerome, Gregory; Ternier, Ralph; Ivers, Louise C

2018-01-01

Abstract Background Cholera continues to be a major cause of morbidity and mortality worldwide and is now endemic in Haiti since first being introduced in 2010. Cholera and HIV have significant geographic overlap globally, but little is known about the clinical features and risk of cholera among HIV-infected people and their households. Methods We assessed HIV-affected households originally recruited for a randomized controlled trial of food supplements. We assessed for correlation between household and individual factors and reported history of cholera since 2010 using univariable and multivariable analyses. Results There were 352 HIV-infected household members, 32 with reported history of medically attended cholera, and 1968 other household members, 55 with reported history of medically attended cholera. Among HIV-infected individuals in this study, no variables correlated with reported history of cholera in univariable analyses. Among all household members, known HIV infection (adjusted odds ratio [AOR], 3.75; 95% CI, 2.43–5.79; P < .0001), source of income in the household (AOR, 1.82; 95% CI, 1.05–3.15; P = .034), time required to fetch water (AOR, 1.07 per 5-minute increase; 95% CI, 1.01–1.12; P = .015), and severe household food insecurity (AOR, 3.23; 95% CI, 1.25–8.34; P = .016) were correlated with reported history of cholera in a multivariable analysis. Conclusions Known HIV infection, source of household income, time required to fetch water, and severe household food insecurity were independently associated with reported history of medically attended cholera in HIV-affected households in rural Haiti. Further research is required to better understand the interactions between HIV and cholera. PMID:29942825

Prevalence of vibrio cholerae and salmonella in a major shrimp production area in Thailand.

PubMed

Dalsgaard, A; Huss, H H; H-Kittikun, A; Larsen, J L

1995-11-01

In 1992 and 1993, a 7 months study carried out in a major shrimp-producing area in Southern Thailand to study the prevalence of Vibrio cholerae and Salmonella. A total of 158 samples were examined including water, sediment, shrimp, pelleted feed, shrimp gut, and chicken manure. Salmonella was not recovered from any sample type studied. V. cholerae O1 was isolated from 2 (2%) and V. cholerae non-O1 was isolated from 35 (33%) of 107 samples examined. The occurrence of V. cholerae was not significantly influenced by water salinity, temperature, dissolved oxygen or pH. There was no correlation between fecal coliform counts and the prevalence of V. cholerae. The results indicate that V. cholerae non-O1 is ubiquitous in aquatic environments where shrimp culture is practised under a variety of environmental conditions. The public health significance of non-O1 V. cholerae in shrimp culture remains to be determined. V. cholerae O1 and Salmonella do not appear to constitute a hygienic problem even if chicken manure was used as fertilizer.

Environmental factor analysis of cholera in China using remote sensing and geographical information systems.

PubMed

Xu, M; Cao, C X; Wang, D C; Kan, B; Xu, Y F; Ni, X L; Zhu, Z C

2016-04-01

Cholera is one of a number of infectious diseases that appears to be influenced by climate, geography and other natural environments. This study analysed the environmental factors of the spatial distribution of cholera in China. It shows that temperature, precipitation, elevation, and distance to the coastline have significant impact on the distribution of cholera. It also reveals the oceanic environmental factors associated with cholera in Zhejiang, which is a coastal province of China, using both remote sensing (RS) and geographical information systems (GIS). The analysis has validated the correlation between indirect satellite measurements of sea surface temperature (SST), sea surface height (SSH) and ocean chlorophyll concentration (OCC) and the local number of cholera cases based on 8-year monthly data from 2001 to 2008. The results show the number of cholera cases has been strongly affected by the variables of SST, SSH and OCC. Utilizing this information, a cholera prediction model has been established based on the oceanic and climatic environmental factors. The model indicates that RS and GIS have great potential for designing an early warning system for cholera.

Cholera after the consumption of raw oysters. A case report.

PubMed

Klontz, K C; Tauxe, R V; Cook, W L; Riley, W H; Wachsmuth, I K

1987-12-01

In August 1986, a 76-year-old woman in Miami, Florida, developed profuse watery diarrhea and abdominal cramps. Two and four days before the onset of her illness, she had eaten six raw oysters at each of two restaurants in Miami. A stool specimen yielded toxigenic Vibrio cholerae O1 biotype El Tor, serotype Inaba. The results of toxin gene probing of the organism recovered from the patient differed significantly from those of other V. cholerae O1 isolates from the Gulf Coast and elsewhere in the world. A program of active surveillance identified no other cases of cholera in Miami. The source of the raw oysters eaten by the patient was traced to Louisiana. Her case represents the first reported case of cholera associated with eating raw oysters.

Environmental reservoirs and mechanisms of persistence of Vibrio cholerae

PubMed Central

Lutz, Carla; Erken, Martina; Noorian, Parisa; Sun, Shuyang; McDougald, Diane

2013-01-01

It is now well accepted that Vibrio cholerae, the causative agent of the water-borne disease cholera, is acquired from environmental sources where it persists between outbreaks of the disease. Recent advances in molecular technology have demonstrated that this bacterium can be detected in areas where it has not previously been isolated, indicating a much broader, global distribution of this bacterium outside of endemic regions. The environmental persistence of V. cholerae in the aquatic environment can be attributed to multiple intra- and interspecific strategies such as responsive gene regulation and biofilm formation on biotic and abiotic surfaces, as well as interactions with a multitude of other organisms. This review will discuss some of the mechanisms that enable the persistence of this bacterium in the environment. In particular, we will discuss how V. cholerae can survive stressors such as starvation, temperature, and salinity fluctuations as well as how the organism persists under constant predation by heterotrophic protists. PMID:24379807

Spatially explicit modelling of cholera epidemics

NASA Astrophysics Data System (ADS)

Finger, F.; Bertuzzo, E.; Mari, L.; Knox, A. C.; Gatto, M.; Rinaldo, A.

2013-12-01

Epidemiological models can provide crucial understanding about the dynamics of infectious diseases. Possible applications range from real-time forecasting and allocation of health care resources to testing alternative intervention mechanisms such as vaccines, antibiotics or the improvement of sanitary conditions. We apply a spatially explicit model to the cholera epidemic that struck Haiti in October 2010 and is still ongoing. The dynamics of susceptibles as well as symptomatic and asymptomatic infectives are modelled at the scale of local human communities. Dissemination of Vibrio cholerae through hydrological transport and human mobility along the road network is explicitly taken into account, as well as the effect of rainfall as a driver of increasing disease incidence. The model is calibrated using a dataset of reported cholera cases. We further model the long term impact of several types of interventions on the disease dynamics by varying parameters appropriately. Key epidemiological mechanisms and parameters which affect the efficiency of treatments such as antibiotics are identified. Our results lead to conclusions about the influence of different intervention strategies on the overall epidemiological dynamics.

Effectiveness of Oral Cholera Vaccine in Haiti: 37-Month Follow-Up.

PubMed

Sévère, Karine; Rouzier, Vanessa; Anglade, Stravinsky Benedict; Bertil, Claudin; Joseph, Patrice; Deroncelay, Alexandra; Mabou, Marie Marcelle; Wright, Peter F; Guillaume, Florence Duperval; Pape, Jean William

2016-05-04

The first oral cholera vaccine (OCV) campaign, since its prequalification by the World Health Organization, in response to an ongoing cholera epidemic (reactive vaccination) was successfully conducted in a poor urban slum of approximately 70,000 inhabitants in Port-au-Prince, Haiti, in 2012. Vaccine coverage was 75% of the target population. This report documents the impact of OCV in reducing the number of culture-confirmed cases of cholera admitted to the Groupe Haïtien d'Etude du Sarcome de Kaposi et des Infections Opportunistes (GHESKIO) cholera treatment center from that community in the 37 months postvaccination (April 2012-April 30, 2015). Of 1,788 patients with culture-confirmed cholera, 1,770 (99%) were either from outside the vaccine area (1,400 cases) or from the vaccinated community who had not received OCV (370 cases). Of the 388 people from the catchment area who developed culture-confirmed cholera, 370 occurred among the 17,643 people who had not been vaccinated (2.1%) and the remaining 18 occurred among the 52,357 people (0.034%) who had been vaccinated (P < 0.001), for an efficacy that approximates 97.5%. Despite not being designed as a randomized control trial, the very high efficacy is a strong evidence for the effectiveness of OCV as part of an integrated package for the control of cholera in outbreak settings. © The American Society of Tropical Medicine and Hygiene.

The African cholera surveillance network (Africhol) consortium meeting, 10-11 June 2015, Lomé, Togo.

PubMed

Munier, Aline; Njanpop-Lafourcade, Berthe-Marie; Sauvageot, Delphine; Mhlanga, Raymond B; Heyerdahl, Léonard; Nadri, Johara; Wood, Richard; Ouedraogo, Issaka; Blake, Alexandre; Akilimali Mukelenge, Laurent; Anné, Jean-Claude B; Banla Kere, Abiba; Dempouo, Lucienne; Keita, Sakoba; Langa, José P M; Makumbi, Issa; Mwakapeje, Elibariki R; Njeru, Ian J; Ojo, Olubunmi E; Phiri, Isaac; Pezzoli, Lorenzo; Gessner, Bradford D; Mengel, Martin

2017-01-01

The fifth annual meeting of the African cholera surveillance network (Africhol) took place on 10-11 June 2015 in Lomé, Togo. Together with international partners, representatives from the 11 member countries -Cameroon, Côte d'Ivoire, Democratic Republic of Congo, Guinea, Kenya, Mozambique, Nigeria, Tanzania, Togo, Uganda, Zimbabwe- and an invited country (Malawi) shared their experience. The meeting featured three sessions: i) cholera surveillance, prevention and control in participating countries, ii) cholera surveillance methodology, such as cholera mapping, cost-effectiveness studies and the issue of overlapping epidemics from different diseases, iii) cholera laboratory diagnostics tools and capacity building. The meeting has greatly benefitted from the input of technical expertise from participating institutions and the observations emerging from the meeting should enable national teams to make recommendations to their respective governments on the most appropriate and effective measures to be taken for the prevention and control of cholera. Recommendations for future activities included collecting precise burden estimates in surveillance sites; modeling cholera burden for Africa; setting up cross-border collaborations; strengthening laboratory capacity for the confirmation of suspected cholera cases and for vaccine impact assessment in settings where oral cholera vaccine would be used; adapting cholera surveillance to concurrent issues (e.g., Ebola); and developing national cholera control plans including rationale vaccination strategies together with other preventive and control measures such as improvements in water, sanitation and hygiene (WASH).

A global map of suitability for coastal Vibrio cholerae under current and future climate conditions.

PubMed

Escobar, Luis E; Ryan, Sadie J; Stewart-Ibarra, Anna M; Finkelstein, Julia L; King, Christine A; Qiao, Huijie; Polhemus, Mark E

2015-09-01

Vibrio cholerae is a globally distributed water-borne pathogen that causes severe diarrheal disease and mortality, with current outbreaks as part of the seventh pandemic. Further understanding of the role of environmental factors in potential pathogen distribution and corresponding V. cholerae disease transmission over time and space is urgently needed to target surveillance of cholera and other climate and water-sensitive diseases. We used an ecological niche model (ENM) to identify environmental variables associated with V. cholerae presence in marine environments, to project a global model of V. cholerae distribution in ocean waters under current and future climate scenarios. We generated an ENM using published reports of V. cholerae in seawater and freely available remotely sensed imagery. Models indicated that factors associated with V. cholerae presence included chlorophyll-a, pH, and sea surface temperature (SST), with chlorophyll-a demonstrating the greatest explanatory power from variables selected for model calibration. We identified specific geographic areas for potential V. cholerae distribution. Coastal Bangladesh, where cholera is endemic, was found to be environmentally similar to coastal areas in Latin America. In a conservative climate change scenario, we observed a predicted increase in areas with environmental conditions suitable for V. cholerae. Findings highlight the potential for vulnerability maps to inform cholera surveillance, early warning systems, and disease prevention and control. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Cholera with severe renal failure in an Italian tourist returning from Cuba, July 2013.

PubMed

Mascarello, M; Deiana, M L; Maurel, C; Lucarelli, C; Luzzi, I; Luzzati, R

2013-08-29

In July 2013, an Italian tourist returning from Cuba was hospitalised in Trieste, Italy, for cholera caused by Vibrio cholerae O1 serotype Ogawa with severe renal failure. An outbreak of cholera was reported in Cuba in January 2013. Physicians should consider the diagnosis of cholera in travellers returning from Cuba presenting with acute watery diarrhoea.

Linking Satellite Derived Land Surface Temperature with Cholera: A Case Study for South Sudan

NASA Astrophysics Data System (ADS)

Aldaach, H. S. V.; Jutla, A.; Akanda, A. S.; Colwell, R. R.

2014-12-01

A sudden onset of cholera in South Sudan, in April 2014 in Northern Bari in Juba town resulted in more than 400 cholera cases after four weeks of initial outbreak with a case of fatality rate of CFR 5.4%. The total number of reported cholera cases for the period of April to July, 2014 were 5,141 including 114 deaths. With the limited efficacy of cholera vaccines, it is necessary to develop mechanisms to predict cholera occurrence and thereafter devise intervention strategies for mitigating impacts of the disease. Hydroclimatic processes, primarily precipitation and air temperature are related to epidemic and episodic outbreak of cholera. However, due to coarse resolution of both datasets, it is not possible to precisely locate the geographical location of disease. Here, using Land Surface Temperature (LST) from MODIS sensors, we have developed an algorithm to identify regions susceptible for cholera. Conditions for occurrence of cholera were detectable at least one month in advance in South Sudan and were statistically sensitive to hydroclimatic anomalies of land surface and air temperature, and precipitation. Our results indicate significant spatial and temporal averaging required to infer usable information from LST over South Sudan. Preliminary results that geographically location of cholera outbreak was identifiable within 1km resolution of the LST data.

Risk Map of Cholera Infection for Vaccine Deployment: The Eastern Kolkata Case

PubMed Central

You, Young Ae; Ali, Mohammad; Kanungo, Suman; Sah, Binod; Manna, Byomkesh; Puri, Mahesh; Nair, G. Balakrish; Bhattacharya, Sujit Kumar; Convertino, Matteo; Deen, Jacqueline L.; Lopez, Anna Lena; Wierzba, Thomas F.; Clemens, John; Sur, Dipika

2013-01-01

Background Despite advancement of our knowledge, cholera remains a public health concern. During March-April 2010, a large cholera outbreak afflicted the eastern part of Kolkata, India. The quantification of importance of socio-environmental factors in the risk of cholera, and the calculation of the risk is fundamental for deploying vaccination strategies. Here we investigate socio-environmental characteristics between high and low risk areas as well as the potential impact of vaccination on the spatial occurrence of the disease. Methods and Findings The study area comprised three wards of Kolkata Municipal Corporation. A mass cholera vaccination campaign was conducted in mid-2006 as the part of a clinical trial. Cholera cases and data of the trial to identify high risk areas for cholera were analyzed. We used a generalized additive model (GAM) to detect risk areas, and to evaluate the importance of socio-environmental characteristics between high and low risk areas. During the one-year pre-vaccination and two-year post-vaccination periods, 95 and 183 cholera cases were detected in 111,882 and 121,827 study participants, respectively. The GAM model predicts that high risk areas in the west part of the study area where the outbreak largely occurred. High risk areas in both periods were characterized by poor people, use of unsafe water, and proximity to canals used as the main drainage for rain and waste water. Cholera vaccine uptake was significantly lower in the high risk areas compared to low risk areas. Conclusion The study shows that even a parsimonious model like GAM predicts high risk areas where cholera outbreaks largely occurred. This is useful for indicating where interventions would be effective in controlling the disease risk. Data showed that vaccination decreased the risk of infection. Overall, the GAM-based risk map is useful for policymakers, especially those from countries where cholera remains to be endemic with periodic outbreaks. PMID:23936491

Private sector response against the cholera threat in Trinidad and Tobago.

PubMed

Hospedales, J; Holder, Y; Deyalsingh, I; Paul, R; Rosenbaum, J

1993-01-01

During the first half of 1992 the threat of cholera to Trinidad and Tobago prompted a strong health education effort by public authorities and the private sector. To help assess the private sector effort, the cost of cholera-related advertisements and private announcements placed in the country's two leading newspapers during January-June 1992 were reviewed. The review indicated that an estimated TT$ 540,660 was spent on these ads and announcements, that they contributed strongly to keeping cholera prevention continuously in the public eye, and that most of the messages published were accurate, specific, and safe. The strength and success of the private contribution to cholera prevention in this case suggests that similar approaches could be applied to other health problems and to the cholera problem outside Trinidad and Tobago. Overall, the lesson appears to be that if one can find congruence between private sector motives and public health interests, then the potential prospects for a successful partnership are great.

Some observations on the cholera (El Tor) epidemic in 1961-62

PubMed Central

Felsenfeld, Oscar

1963-01-01

The author discusses some of the features of the cholera epidemic caused by El Tor vibrios in 1961-62 in the Western Pacific. The disease originated in the Celebes and spread from there to other parts of Indonesia, to Sarawak and, possibly, to Kwangtung. Hong Kong and Macau were most probably infected from Kwangtung. Subsequently the disease reached the Philippines, progressing from Manila southwards to the other islands, whence it invaded British Borneo. The El Tor epidemic did not differ clinically or epidemiologically from other cholera outbreaks observed during the past decade. The disease attacked poor, under-nourished people living under insanitary conditions. It spread along the coastline and, to a limited extent, along inland waterways. The authorities in the affected territories recommended that the quarantine regulations, sanitary measures and treatment methods used against cholera caused by the so-called “true” cholera vibrios be applied also to cholera caused by El Tor vibrios. PMID:13962884

Cost-benefit comparisons of investments in improved water supply and cholera vaccination programs.

PubMed

Jeuland, Marc; Whittington, Dale

2009-05-18

This paper presents the first cost-benefit comparison of improved water supply investments and cholera vaccination programs. Specifically, we compare two water supply interventions -- deep wells with public hand pumps and biosand filters (an in-house, point-of-use water treatment technology) -- with two types of cholera immunization programs with new-generation vaccines -- general community-based and targeted and school-based programs. In addition to these four stand-alone investments, we also analyze five combinations of water and vaccine interventions: (1) borehole+hand pump and community-based cholera vaccination, (2) borehole+hand pump and school-based cholera vaccination, (3) biosand filter and community-based cholera vaccination, (4) biosand filter and school-based cholera vaccination, and (5) biosand filter and borehole+hand pump. Using recent data applicable to developing country locations for parameters such as disease incidence, the effectiveness of vaccine and water supply interventions against diarrheal diseases, and the value of a statistical life, we construct cost-benefit models for evaluating these interventions. We then employ probabilistic sensitivity analysis to estimate a frequency distribution of benefit-cost ratios for all four interventions, given a wide variety of possible parameter combinations. Our results demonstrate that there are many plausible conditions in developing countries under which these interventions will be attractive, but that the two improved water supply interventions and the targeted cholera vaccination program are much more likely to yield attractive cost-benefit outcomes than a community-based vaccination program. We show that implementing community-based cholera vaccination programs after borehole+hand pump or biosand filters have already been installed will rarely be justified. This is especially true when the biosand filters are already in place, because these achieve substantial cholera risk reductions on their own

Critical Analysis of Compositions and Protective Efficacies of Oral Killed Cholera Vaccines

PubMed Central

2014-01-01

Two cholera vaccines, sold as Shanchol and Dukoral, are currently available. This review presents a critical analysis of the protective efficacies of these vaccines. Children under 5 years of age are very vulnerable to cholera and account for the highest incidence of cholera cases and more than half of the resulting deaths. Both Shanchol and Dukoral are two-spaced-dose oral vaccines comprising large numbers of killed cholera bacteria. The former contains Vibrio cholerae O1 and O139 cells, and the latter contains V. cholerae O1 cells with the recombinant B subunit of cholera toxin. In a field trial in Kolkata (India), Shanchol, the preferred vaccine, protected 45% of the test subjects in all of the age groups and only 17% of the children under 5 years of age during the first year of surveillance. In a field trial in Peru, two spaced doses of Dukoral offered negative protection in children under 5 years of age and little protection (15%) in vaccinees over 6 years of age during the first year of surveillance. Little is known about Dukoral's long-term protective efficacy. Both of these vaccines have questionable compositions, using V. cholerae O1 strains isolated in 1947 that have been inactivated by heat and formalin treatments that may denature protein. Immunological studies revealed Dukoral's reduced and short-lived efficacy, as measured by several immunological endpoints. Various factors, such as the necessity for multiple doses, poor protection of children under 5 years of age, the requirement of a cold supply chain, production costs, and complex logistics of vaccine delivery, greatly reduce the suitability of either of these vaccines for endemic or epidemic cholera control in resource-poor settings. PMID:25056361

Comparative effectiveness of different strategies of oral cholera vaccination in bangladesh: a modeling study.

PubMed

Dimitrov, Dobromir T; Troeger, Christopher; Halloran, M Elizabeth; Longini, Ira M; Chao, Dennis L

2014-12-01

Killed, oral cholera vaccines have proven safe and effective, and several large-scale mass cholera vaccination efforts have demonstrated the feasibility of widespread deployment. This study uses a mathematical model of cholera transmission in Bangladesh to examine the effectiveness of potential vaccination strategies. We developed an age-structured mathematical model of cholera transmission and calibrated it to reproduce the dynamics of cholera in Matlab, Bangladesh. We used the model to predict the effectiveness of different cholera vaccination strategies over a period of 20 years. We explored vaccination programs that targeted one of three increasingly focused age groups (the entire vaccine-eligible population of age one year and older, children of ages 1 to 14 years, or preschoolers of ages 1 to 4 years) and that could occur either as campaigns recurring every five years or as continuous ongoing vaccination efforts. Our modeling results suggest that vaccinating 70% of the population would avert 90% of cholera cases in the first year but that campaign and continuous vaccination strategies differ in effectiveness over 20 years. Maintaining 70% coverage of the population would be sufficient to prevent sustained transmission of endemic cholera in Matlab, while vaccinating periodically every five years is less effective. Selectively vaccinating children 1-14 years old would prevent the most cholera cases per vaccine administered in both campaign and continuous strategies. We conclude that continuous mass vaccination would be more effective against endemic cholera than periodic campaigns. Vaccinating children averts more cases per dose than vaccinating all age groups, although vaccinating only children is unlikely to control endemic cholera in Bangladesh. Careful consideration must be made before generalizing these results to other regions.

A model to predict when a cholera outbreak might hit the Congo

NASA Astrophysics Data System (ADS)

Schultz, Colin

2014-09-01

In 2011, as many as 600,000 people in 58 countries contracted cholera, with thousands succumbing to the disease. In most countries, cholera is rare. In others, like the Democratic Republic of the Congo, cholera is an endemic threat, always lurking in the background waiting for the right set of conditions to spark an outbreak.

The discovery of cholera - like enterotoxins produced by Escherichia coli causing secretory diarrhoea in humans

PubMed Central

Sack, R. Bradley

2011-01-01

Non-vibrio cholera has been recognized as a clinical entity for as long as cholera was known to be caused by Vibrio cholerae. Until 1968, the aetiologic agent of this syndrome was not known. Following a series of studies in patients with non-vibrio cholera it was found that these patients had large concentrations of Escherichia coli in the small bowel and stools which produced cholera toxin-like enterotoxins, and had fluid and electrolyte transport abnormalities in the small bowel similar to patients with documented cholera. Furthermore, these patients developed antibodies to the cholera-like enterotoxin. Later studies showed that these strains, when fed to volunteers produced a cholera-like disease and that two enterotoxins were found to be produced by these organisms: a heat-labile enterotoxin (LT) which is nearly identical to cholera toxin, and a heat-stable enterotoxin (ST), a small molecular weight polypeptide. E. coli that produced one or both of these enterotoxins were designated enterotoxigenic E. coli (ETEC). ETEC are now known not only to cause a severe cholera-like illness, but to be the most common bacterial cause of acute diarrhoea in children in the developing world, and to be the most common cause of travellers’ diarrhoea in persons who visit the developing world. PMID:21415491

The true burden and risk of cholera: implications for prevention and control.

PubMed

Zuckerman, Jane N; Rombo, Lars; Fisch, Alain

2007-08-01

Cholera is a substantial health burden on the developing world and is endemic in Africa, Asia, South America, and Central America. The exact scale of the problem is uncertain because of limitations in existing surveillance systems, differences in reporting procedures, and failure to report cholera to WHO; official figures are likely to greatly underestimate the true prevalence of the disease. We have identified, through extensive literature searches, additional outbreaks of cholera to those reported to WHO, many of which originated from the Indian subcontinent and southeast Asia. Such underestimation of cholera can have important implications for decisions on provision of health interventions for indigenous populations, and on risk assessments for travellers. Furthermore, until recently, it has not been possible to implement public-health interventions in low-income countries to eliminate disease, and the prevention of cholera in travellers has been limited to restrictive guidelines. However, a vaccine against cholera is now available that has proven efficacy and tolerability in mass vaccination campaigns in low-income countries, and among travellers.

Biotype-specific tcpA genes in Vibrio cholerae.

PubMed

Iredell, J R; Manning, P A

1994-08-01

The tcpA gene, encoding the structural subunit of the toxin-coregulated pilus, has been isolated from a variety of clinical isolates of Vibrio cholerae, and the nucleotide sequence determined. Strict biotype-specific conservation within both the coding and putative regulatory regions was observed, with important differences between the El Tor and classical biotypes. V. cholerae O139 Bengal strains appear to have El Tor-type tcpA genes. Environmental O1 and non-O1 isolates have sequences that bind an El Tor-specific tcpA DNA probe and that are weakly and variably amplified by tcpA-specific polymerase chain reaction primers, under conditions of reduced stringency. The data presented allow the selection of primer pairs to help distinguish between clinical and environmental isolates, and to distinguish El Tor (and Bengal) biotypes from classical biotypes of V. cholerae. While the role of TcpA in cholera vaccine preparations remains unclear, the data strongly suggest that TcpA-containing vaccines directed at O1 strains need include only the two forms of TcpA, and that such vaccines directed at (O139) Bengal strains should include the TcpA of El Tor biotype.

Cholera toxin can catalyze ADP-ribosylation of cytoskeletal proteins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaslow, H.R.; Groppi, V.E.; Abood, M.E.

1981-11-01

Cholera toxin catalyzes transfer of radiolabel from (/sup 32/P)NAD/sup +/ to several peptides in particulate preparations of human foreskin fibroblasts. Resolution of these peptides by two-dimensional gel electrophoresis allowed identification of two peptides of M/sub r/ = 42,000 and 52,000 as peptide subunits of a regulatory component of adenylate cyclase. The radiolabeling of another group of peptides (M/sub r/ = 50,000 to 65,000) suggested that cholera toxin could catalyze ADP-ribosylation of cytoskeletal proteins. This suggestion was confirmed by showing that incubation with cholera toxin and (/sup 32/P)NAD/sup +/ caused radiolabeling of purified microtubule and intermediate filament proteins.

Comparative proteomic analysis reveals activation of mucosal innate immune signaling pathways during cholera.

PubMed

Ellis, Crystal N; LaRocque, Regina C; Uddin, Taher; Krastins, Bryan; Mayo-Smith, Leslie M; Sarracino, David; Karlsson, Elinor K; Rahman, Atiqur; Shirin, Tahmina; Bhuiyan, Taufiqur R; Chowdhury, Fahima; Khan, Ashraful Islam; Ryan, Edward T; Calderwood, Stephen B; Qadri, Firdausi; Harris, Jason B

2015-03-01

Vibrio cholerae O1 is a major cause of acute watery diarrhea in over 50 countries. Evidence suggests that V. cholerae O1 may activate inflammatory pathways, and a recent study of a Bangladeshi population showed that variants in innate immune genes play a role in mediating susceptibility to cholera. We analyzed human proteins present in the small intestine of patients infected with V. cholerae O1 to characterize the host response to this pathogen. We collected duodenal biopsy specimens from patients with acute cholera after stabilization and again 30 days after initial presentation. Peptides extracted from biopsy specimens were sequenced and quantified using label-free mass spectrometry and SEQUEST. Twenty-seven host proteins were differentially abundant between the acute and convalescent stages of infection; the majority of these have known roles in innate defense, cytokine production, and apoptosis. Immunostaining confirmed that two proteins, WARS and S100A8, were more abundant in lamina propria cells during the acute stage of cholera. Analysis of the differentially abundant proteins revealed the activation of key regulators of inflammation by the innate immune system, including Toll-like receptor 4, nuclear factor kappa-light-chain-enhancer of activated B cells, mitogen-activated protein kinases, and caspase-dependent inflammasomes. Interleukin-12β (IL-12β) was a regulator of several proteins that were activated during cholera, and we confirmed that IL-12β was produced by lymphocytes recovered from duodenal biopsy specimens of cholera patients. Our study shows that a broad inflammatory response is generated in the gut early after onset of cholera, which may be critical in the development of long-term mucosal immunity against V. cholerae O1. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Detection of ctx gene positive non-O1/non-O139 V. cholerae in shrimp aquaculture environments.

PubMed

Madhusudana, Rao B; Surendran, P K

2013-06-01

Water and post-larvae samples from black tiger (Penaeus monodon) shrimp hatcheries; pond water, pond sediment and shrimp from aquaculture farms were screened for the presence of V. cholerae. A V. cholerae-duplex PCR method was developed by utilizing V. cholerae species specific sodB primers and ctxAB genes specific primers. Incidence of V. cholerae was not observed in shrimp hatchery samples but was noticed in aquaculture samples. The incidence of V. cholerae was higher in pond water (7.6%) than in pond sediment (5.2%). Shrimp head (3.6%) portion had relatively higher incidence than shrimp muscle (1.6%). All the V. cholerae isolates (n = 42) belonged to non-O1/non-O139 serogroup, of which 7% of the V. cholerae isolates were potentially cholera-toxigenic (ctx positive). All the ctx positive V. cholerae (n = 3) were isolated from the pond water. Since, cholera toxin (CT) is the major contributing factor for cholera gravis, it is proposed that the mere presence of non-O1/non-O139 V. cholerae need not be the biohazard criterion in cultured black tiger shrimp but only the presence of ctx carrying non-O1/non-O139 V. cholerae may be considered as potential public health risk.

The Costs of Climate Change: A Study of Cholera in Tanzania

PubMed Central

Trærup, Sara L. M.; Ortiz, Ramon A.; Markandya, Anil

2011-01-01

Increased temperatures and changes in rainfall patterns as a result of climate change are widely recognized to entail potentially serious consequences for human health, including an increased risk of diarrheal diseases. This study integrates historical data on temperature and rainfall with the burden of disease from cholera in Tanzania and uses socioeconomic data to control for the impacts of general development on the risk of cholera. The results show a significant relationship between temperature and the incidence of cholera. For a 1 degree Celsius temperature increase the initial relative risk of cholera increases by 15 to 29 percent. Based on the modeling results, we project the number and costs of additional cases of cholera that can be attributed to climate change by 2030 in Tanzania for a 1 and 2 degree increase in temperatures, respectively. The total costs of cholera attributable to climate change are shown to be in the range of 0.32 to 1.4 percent of GDP in Tanzania 2030. The results provide useful insights into national-level estimates of the implications of climate change on the health sector and offer information which can feed into both national and international debates on financing and planning adaptation. PMID:22408580