A cholera epidemic can be predicted through satellite imaging of sea and river estuaries to study the plankton on which cholera causing viruses grow.

US-based cholera researcher Rita Colwell said vibrio cholerae, the cholera-causing virus, grows on plankton found in the sea and river estuaries. Changes in sea temperature due to planktons can be mapped by remote-sensing satellites, which can in turn predict the population of vibrio cholerae, Colwell told the Indian Science Congress here.

Colwell said she had predicted a cholera outbreak of 24.8 percent in Bangladesh in 2004 through satellite. The actual epidemic was just 25 percent. She has been studying cholera in Bangladesh for the past 20 years. She is now concentrating on preparing a global prediction model for a cholera outbreak through the method.

Cotton saris folded four times over can be used as an effective medium to filter water and keep out the cholera virus and the plankton, she said.

"Ecology cannot be separated from epidemiology. Similarly, vibrio cholerae is a part of nature, and an integral part of the nitrogen cycle. We can never eradicate it, but it is very easy to prevent cholera," Colwell said.