November 11, 2008
Scientists Use Satellites To Track Cholera Outbreaks
Researchers say they are now using satellite monitoring of marine environments for predicting cholera outbreaks.
Cholera outbreaks follow seasonal increases in sea temperature, scientists said, and this could provide an early warning system for India and Bangladesh where cholera epidemics occur regularly.
Tiny animals, which increase in number with sea temperature rise, bring the cholera pathogen into the drinking water supply.
The satellites were able to pick up sea temperature changes in the Bay of Bengal and measure the amount of phytoplankton, the tiny marine plants that feed ocean ecosystems.
Cholera outbreaks soon followed in Kolkata (Calcutta) in India and Matlab in Bangladesh after seasonal rises in sea temperature lead to increases in phytoplankton densities.
Professor Rita Colwell, from the Institute for Advanced Computer Studies at the University of Maryland, said satellite monitoring holds the key to preventing cholera epidemics.
"We can use the current data taken from the satellites to predict when the onset of cholera epidemics will occur, it allows public health authorities to pinpoint exactly when to allocate resources or implement warnings about drinking the water," said Colwell, who has been studying cholera outbreaks for over 30 years.
The cholera pathogen lives naturally in the gut of a zooplankton species - tiny marine animals called copepods, these feed on the phytoplankton.
Copepods find their way into the water supply when sea levels rise in low-lying parts of Bangladesh and India.
Using simple cloth filters to remove the copepods can dramatically reduce the incidence of cholera, Colwell says.
"We found we could reduce cholera 40-50% by just filtering out the plankton," she said.
By using satellite monitoring, the researchers hope to soon be able to predict cholera outbreaks weeks or even months before they occur.
The satellites will allow scientists to look at what is happening further out to sea, examining the timings of ocean currents and associated growths in plankton numbers.
Image Caption: Copepods find their way into the water supply when sea levels rise in low-lying parts of Bangladesh and India. Image Courtesy Uwe Kils - Wikipedia
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