Research published in the February 2005 issue of Proceedings of the National Academy of Science provides intriguing insight into cholera outbreaks, and may someday lead to a method of predicting or even preventing such epidemics.
After studying levels of cholera bacteria (Vibrio cholerae) in water, researchers at the International Center for Diarrhoeal Disease Research and Harvard Medical School noticed a relationship between the level of cholera bacteria and the presence of phage — a virus that uses bacteria to reproduce itself.
There was an inverse relationship between the two: as the level of phage increased, the number of cholera bacteria declined. Similarly, when phage levels fell, cholera bacteria levels increased.
It is somewhat of mystery why cholera plagues are self-limiting and tend to end of their own accord. This research provides one possible answer, namely that cholera outbreaks might begin when phenomena such as monsoons dilute the amount of phage in water, and then end of their own accord once phage levels again increase.
Much more research needs to be done to establish the precise relationship between phage and cholera bacteria, but this study provides intriguing clues that may help to predict and ultimately prevent cholera outbreaks.
Sources:
Cholera understanding ‘improved’. The BBC, January 16, 2005.
New insights: Why are cholera epidemics self-limited?. Press Release, International Center for Diarrhoeal Disease Research, March 7, 2005.