  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.
