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How does chlorinating public water supplies help control cholera?

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A woman in a pink dress receives medical treatment from nurses administering an IV at a crowded hospital in Saint-Marc, Haiti. — cholera A woman with cholera being treated by nurses at St. Nicholas Hospital in Saint-Marc, Haiti, 2010.

Chlorinating public water supplies is a critical intervention for controlling cholera because it serves as a highly effective method of disinfection.

Cholera is an intestinal disease that spreads primarily through the fecal-oral route, often when water sources become contaminated with feces containing the bacterium Vibrio cholerae. By applying chlorine or chlorine compounds to drinking water, water treatment facilities can destroy these pathogenic [bacteria].123

This process is typically the final stage of water treatment, ensuring that the water is safe for consumption. A key advantage of chlorination is that a residual concentration of chlorine can be maintained throughout the water distribution system, providing ongoing protection against contamination until the water reaches the point of use. The implementation of such water-treatment technologies has been instrumental in the virtual elimination of cholera in many developed countries.234