Rain and Temperature Predict Cholera Risks

Increases in average temperature and rainfall were associated in Zanzibar with higher numbers of cholera cases within a definite time period. Steve Mirsky reports

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Bad blood pressure and cholesterol numbers are predictors for future health problems. You won’t definitely have a heart attack, for example, but your risk is higher. Now researchers have developed a similar-style early warning system for the public health of an entire region. They found that an analysis of particular environmental conditions helps predict the risk of an outbreak of the deadly disease cholera. The work is in the American Journal of Tropical Medicine and Hygiene. [Rita Reyburn et al, Climate Variability and the Outbreaks of Cholera in Zanzibar, East Africa: A Time Series Analysis]

The scientists did a kind of retrospective clinical study, in which they analyzed years of both disease and environmental data from the Zanzibar archipelago, and they discovered that in areas already at-risk a one-degree Celsius increase in temperature over the average monthly minimum was associated with a doubling of the cholera cases within the next four months. A 200-millimeter increase in the monthly rainfall total also went along with a big rise in cholera cases within two months.

Cholera bacteria thrive in warm water where sanitation is poor. So the hotter, wetter conditions are just what the doctor did not order. The researchers hope that monitoring the environment can help communities prepare better for cholera outbreaks.

—Steve Mirsky

[The above text is an exact transcript of this podcast.]

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