Principal investigators: Dr. Rita Colwell1 and Dr. Anwar
Co-investigators: B. Lobitz2, L. Beck2, B. Wood2
1 University of Maryland Biotechnology Institute
2 CHAART, NASA Ames Research Center
Cholera epidemics caused by Vibrio cholerae O1 occur regularly in Bangladesh and India and sporadically in many parts of the world. In 1993, a total of 296,206 new cases of cholera were reported in South America after about a century, involving more than 15 countries. The outbreaks of cholera that have occurred during the past decade originated in coastal areas.
From our previous work, V. cholerae attaches to plankton in the aquatic environment, providing the vehicle for dispersal. The organism attaches preferentially to zooplankton, particularly copepods, but it also attaches in lower numbers and without reproduction onto some species of phytoplankton. Phytoplankton provide the main food source for zooplankton so the two forms of plankton are tightly linked in space and time. Under adverse conditions of temperature and nutrients V. cholerae enters a dormant, non-culturable state which makes it difficult to detect. Although V. cholerae cannot be detected in any state by remote sensing techniques, remote sensing has been used successfully to quantify phytoplankton concentrations in the open oceans. The tight linking of zooplankton and V. cholerae indicates remote sensing will be useful in tracking V. cholerae associated with plankton plumes emanating from major rivers where cholera is known to be endemic, i.e., the plume of the Ganges.
This proposal seeks to establish a model driven by satellite remote sensing that will be useful in tracking the spatial and temporal development of such plumes as they impinge on coastal areas, related to outbreaks of cholera. The model will, therefore, be used to provide an early warning system for cholera in coastal areas and enable more effective deployment of resources to counteract, if not prevent, massive epidemics of cholera.
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A short list of suggested reading for cholera information is also available
Last updated: August 2000