Latin American countries are now equipped with a cheap and effective remedy to keep cholera under check, thanks to the researchers at the US Centers for Disease Control and Prevention, Atlanta (Science, Vol 265, No 5171).

Cholera has been the primary epidemic in Latin America since 1991. The pestilence spreads mainly by drinking water from stagnant and faeces-contaminated sources.

Epidemiologist Robert Quick and colleagues have developed an inexpensive water purification system using table salt and a power source. The salt is separated into its constituents, sodium and chlorine, by electric current. Chlorine is then passed through the drinking water source.

The method meets the safety requirements of the World Health Organisation. Quick's team estimates that the cost of clean water for drinking and washing will be 15 cents a month for a family of 5.