Global warming helps cholera

Global warming helps cholera.

Rising temperatures resulting from global warming is to blame for cholera bacteria becoming more widespread, an environmental biologist who has studied the bacterium said yesterday.

Kampol Ruchiwit of Thammasat University's Faculty of Allied Health Sciences told a seminar on the social and economic effects of global warming that instead of the cholera toxin being produced only during summer, it was now produced year-round. He said two strains of the cholera bacterium - Vibrio cholerae 01 and 0139 - produced the cholera toxin.

The consequence is that cholera no longer can be treated as a seasonal disease.

Kampol said Vibrio cholerae 01 and 0139 are found in the environment.

They produce cholera toxin only when infected with a virus called CTX phage. Infection normally occurs in summer, when water temperatures are higher.

Kampol referred to his ongoing four-year research that found infections now occurred year-round. He believes rising water temperatures play a role in this phenomenon.

"Even if the water temperature increased by just 0.5 of a degree Celsius, CTX phage could infect the bacterium," he said.

Kampol said he would continue his study into whether global warming was the only culprit or other environmental factors were playing a role.

"I want my research to set off an alarm - that global warming is not only creating emerging diseases or [exacerbating] diseases caused by insects, such as malaria. Diseases caused by micro-organisms could also worsen," he said.

Janjira Pongrai

The Nation
Friday January 12, 2007