Cholera, caused by Vibrio cholerae serogroups O1 and O139, is the most severe of diarrheal diseases and continues to cause significant morbidity and mortality throughout the developing world. Presently, it is reported in approximately 52 countries worldwide. During our first study, we carried out biweekly clinical and environmental surveillance in four rural areas of Bangladesh. Analysis of our accumulated clinical and environmental data identified factors that are significantly predictive for occurrence of cholera outbreaks, including water temperature, pH, and conductivity of surface water, along with concentrations of plankton and cholera toxin- producing bacteria in surface waters. A significant finding was that zooplankton, namely copepods, serve as an effective host for V. cholerae. By tracking their phytoplankton food source, using satellite monitoring of chlorophyll a concentration, it is possible to estimate zooplankton populations. With our successes to date, we will conduct epidemiological and ecological surveillance in Chattak and Mathbaria, two widely separated geographical sites, where we have documented predictable seasonal cholera outbreaks: one in the spring and the other in the fall. Using improved assays, we will enumerate multiple morphologies and life stages of V. cholerae in environmental samples, including the viable but nonculturable form (VBNC). Characterization of genetic associations between clinical and environmental isolates and GIS surveillance will be conducted to establish key epidemiological relationships that have been difficult to document at the genomic level. To elucidate local variability in cholera outbreaks, we will investigate factors recognized from our previous study, as well as those identified by other investigators, but not yet included in our predictive model, namely microbial community dynamics, increased competence of V. cholerae attached to chitinous surfaces, and plankton community dynamics. Using environmental variables identified from our previous studies and incorporating the new variables that prove to be correlated with cholera cases, we will refine our model of cholera transmission with the intent to render it useful for predicting cholera outbreaks, thereby allowing early mobilization of preventative and treatment measures. The very recent availability of inexpensive oral cholera vaccines makes this objective even more relevant.

Public Health Relevance

This project is being done to find reasons why the disease cholera occurs in epidemics. We postulate that factors in the marine environment play important roles in triggering the onset of epidemics. The study is being done in rural Bangladesh, using recently developed technology to further define these factors.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI039129-13
Application #
8280388
Study Section
Infectious Diseases, Reproductive Health, Asthma and Pulmonary Conditions Study Section (IRAP)
Program Officer
Cassels, Frederick J
Project Start
1996-09-01
Project End
2015-05-31
Budget Start
2012-06-01
Budget End
2013-05-31
Support Year
13
Fiscal Year
2012
Total Cost
$1,715,467
Indirect Cost
$92,356
Name
Johns Hopkins University
Department
Public Health & Prev Medicine
Type
Schools of Public Health
DUNS #
001910777
City
Baltimore
State
MD
Country
United States
Zip Code
21218
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George, Christine Marie; Biswas, Shwapon; Jung, Danielle et al. (2017) Psychosocial Factors Mediating the Effect of the CHoBI7 Intervention on Handwashing With Soap: A Randomized Controlled Trial. Health Educ Behav 44:613-625
Rashid, Mahamud-Ur; Rahman, Zillur; Burrowes, Vanessa et al. (2017) Rapid dipstick detection of Vibrio cholerae in household stored and municipal water in Dhaka, Bangladesh: CHoBI7 trial. Trop Med Int Health 22:205-209
Islam, Aminul; Rahman, Zillur; Monira, Shirajum et al. (2017) Colistin resistant Escherichia coli carrying mcr-1 in urban sludge samples: Dhaka, Bangladesh. Gut Pathog 9:77
George, Christine Marie; Sack, David A (2017) Integration of water, sanitation and hygiene intervention delivery at health facilities with a reactive ring vaccination programme to reduce cholera. Int J Epidemiol 46:2093-2094
Burrowes, Vanessa; Perin, Jamie; Monira, Shirajum et al. (2017) Risk Factors for Household Transmission of Vibrio cholerae in Dhaka, Bangladesh (CHoBI7 Trial). Am J Trop Med Hyg 96:1382-1387
George, Christine Marie; Jung, Danielle S; Saif-Ur-Rahman, K M et al. (2016) Sustained Uptake of a Hospital-Based Handwashing with Soap and Water Treatment Intervention (Cholera-Hospital-Based Intervention for 7 Days [CHoBI7]): A Randomized Controlled Trial. Am J Trop Med Hyg 94:428-36
George, Christine Marie; Monira, Shirajum; Sack, David A et al. (2016) Randomized Controlled Trial of Hospital-Based Hygiene and Water Treatment Intervention (CHoBI7) to Reduce Cholera. Emerg Infect Dis 22:233-41
Rashid, Mahamud-Ur; Almeida, Mathieu; Azman, Andrew S et al. (2016) Comparison of inferred relatedness based on multilocus variable-number tandem-repeat analysis and whole genome sequencing of Vibrio cholerae O1. FEMS Microbiol Lett 363:
Vezzulli, Luigi; Grande, Chiara; Reid, Philip C et al. (2016) Climate influence on Vibrio and associated human diseases during the past half-century in the coastal North Atlantic. Proc Natl Acad Sci U S A 113:E5062-71

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