Scientists say climate change may have fuelled Zika outbreak

Record-high temperatures in South American countries created ideal conditions for the mosquito that transmits Zika, researchers have said.
Record-high temperatures in South American countries created ideal conditions for the mosquito that transmits Zika, researchers have said.PHOTO: REUTERS

NEW YORK (BLOOMBERG) - Climate change may have fuelled the outbreak of the mosquito-borne Zika virus in Latin American and make it harder for developing countries to manage future epidemics, researchers said.

Record-high temperatures last year in Brazil, Ecuador and other South America countries created ideal conditions for the mosquito that transmits Zika, which is suspected of causing birth defects, scientists said on conference call with reporters Friday (Feb 5).

The researchers, who cautioned any link between Zika and global warming remains unproven, said violent storms, floods and drought are prone to fostering the outbreak and spread of diseases, particularly in underdeveloped nations.

In addition to creating conditions where viruses can thrive, extreme weather can hobble already over-taxed public health systems.

"Unless mitigated, climate change is likely to bring the spread of new emergent infectious diseases like Zika virus," Nick Watts, who leads a commission on health and climate change for the medical journal The Lancet, said during the call.

Rising temperatures and increased rainfall can extend the geographic range and enrich breeding areas of mosquitoes, ticks, fleas and other insects that transmit diseases, scientists said. The pathogens they carry tend to become more resilient at higher temperatures and go through their life cycles faster.

Warming "is posing risks for the transmission of vector- borne and other diseases," said Diarmid Campbell-Lendrum, the World Health Organization's climate change and health team leader, said in an interview.

The Zika epidemic parallels the 1999 West Nile Virus outbreak in New York, according to Jonathan Patz, director of the Global Health Institute at the University of Wisconsin- Madison. Both arrived during record-hot summers and involved the Aedes aegypti mosquito, which bite more frequently in hot weather.

"I would not want to say that climate is responsible for this," Patz said. "But it's ironic that you have got record hot temperatures."

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