Climate change may alter malaria patterns

STATE COLLEGE, Pa., Feb. 16 (UPI) -- A U.S. entomologist says climate change might alter malaria and other mosquito-borne diseases since global warming can affect parasite development.

Pennsylvania State University Professor Matthew Thomas cautions against merely taking into account average monthly or annual temperatures when considering the spread of malaria and similar diseases. He said global climate change will affect daily temperature variations, which can have a significantly pronounced effect on parasite development.

"A day in the tropics may vary from something like 65 degrees Fahrenheit at night to 86 degrees Fahrenheit in the day, even though the daily average may be 77 degrees Fahrenheit," Thomas said. "Our research suggests this fluctuation matters because it alters the parasite incubation period in the mosquito."

The lower the ambient temperature, the slower the malaria parasite develops. If the incubation period takes longer than the life of the mosquito, the parasite will never infect a human.

"Daily temperature fluctuation can increase or decrease malaria risk, depending on background conditions," said Thomas.

Thomas said that during the first 12 hours of parasite development, temperature fluctuations can be fatal.

"If climate change increases the frequency of days when the temperature quickly exceeds the threshold temperature, then entire cohorts of mosquitoes could fail to develop the parasite," he said.

Thomas presented his research during the weekend in Chicago at a meeting of the Association for the Advancement of Science.