Project Summary
Cholera is a major problem in many parts of the world, and it is endemic in Bangladesh and Vietnam. Research into the indirect causes of cholera indicates that environmental factors such as sea surface temperature and ocean chlorophyll concentration play a role in outbreaks. This investigation uses 25 years of data to examine the environmental drivers of cholera in Bangladesh and Vietnam using population-derived and spatially derived variables. Our research suggests that the effects of both sea surface temperature and ocean chlorophyll concentration have a lag effect and that more rainfall and river discharge usually reduces cholera outbreaks unless localized flooding that inundates water and sanitation systems has the opposite effect. These within and between site comparisons and prediction models are applicable for development of an early warning system for cholera. The project is presently being extended to simultaneously investigate the local-level environmental drivers described above and regional climate drivers such as El Nino.
Project Team Members
Michael Emch
Caryl Feldacker
Veronica Escamilla
Janey Messina
Publications
Ali, M; Kim, DR; Yunus, M; Emch, M. (submitted) Time series analysis of cholera in Matlab, Bangladesh during 1988-2001.
Messina, JP; Emch, M. (submitted) Seasonality of global cholera outbreaks: 1939-2008.
Reiner, R; King, A; Emch, M; Yunus, M; Faruque, A; Pascual, M. (submitted) Highly localized sensitivity to climate forcing drives endemic cholera in a megacity.
Reyburn, R; Kim, DR; Emch, M; Khatib, A; von Seidlein, L; Ali, M. (2011) Climate variability and outbreaks of cholera in Zanzibar, East Africa: a time series analysis. American Journal of Tropical Medicine & Hygiene. 84(6): 862–869. link to article
Carrel, M; Voss, P; Streatfield, K; Yunus, M; Emch, M. (2010) Protection from annual flooding is correlated with increased cholera prevalence in Bangladesh. Environmental Health. 9:13.
Emch, M; Yunus, M; Escamilla, V; Feldacker, C; Ali, M. (2010). Local population and regional environmental drivers of cholera in Bangladesh. Environmental Health. 9:2. link to article
Ruiz-Moreno, D; Pascual, M; Emch, M; Yunus, M. (2010) Spatial clustering in the spatiotemporal dynamics of endemic cholera. BMC Infectious Diseases. 10:51. link to article
Carrel, M; Emch, M; Streatfield, K; Yunus, M. (2009) Spatio-temporal clustering of cholera: the impact of flood control in Matlab, Bangladesh, 1983-2003. Health & Place. 15(3): 771-782. link to article
Emch, M; Feldacker, C; Islam, MS; Ali, M. (2008) Seasonality of cholera from 1974 to 2005: a review of global patterns. International Journal of Health Geographics. 7 (31): 1-33. link to article
Emch, M; Feldacker, C; Yunus, M; Streatfield, PK; Thiem, VD; Canh, DG; Ali, M. (2008) Local environmental drivers of cholera in Bangladesh and Vietnam. American Journal of Tropical Medicine & Hygiene. 78 (5): 823-32. link to article
Ali, M; Emch, ME; Yunus, M; and Sack, RB. (2002) Are the environmental niches of Vibrio cholerae 0139 different from those of Vibrio cholerae 01 El Tor? International Journal of Infectious Disease, 5(4):214-9. link to article
Ali, M; Emch, M; Donnay, JP; Yunus, M; Sack, RB (2002) Identifying environmental risk factors for endemic cholera in Bangladesh: a raster GIS approach. Health & Place, 8(3): 201-210. link to article
Ali, M; Emch, M; Donnay, JP; Yunus, M; Sack, RB. (2002) The spatial epidemiology of cholera in an endemic area of Bangladesh. Social Science and Medicine, 55(6): 1015-1024. link to article
Funding
NOAA: Oceans and Human Health, “Cholera Across Scales: Oceanic Links to Climate and Local Estuarine Influences.” 2005-08.
NOAA: Oceans and Human Health, “Cholera and Climate II: Disentangling the Interactions of Pathogen, Environment and Host Immunity.” 2008-2011.
Collaborating Institutions
International Centre for Diarrhoeal Disease Research, Bangladesh
University of Michigan Ecology and Evolutionary Biology