"Two to three months after that pattern, you see the onset of a malaria epidemic."
The recent outbreaks are particularly worrying because people have not built up immunity to the malaria parasite, according to K. M. Bhatt, an infectious and tropical disease specialist at the University of Nairobi.
"Epidemics are now more deadly, particularly for humans who do not have immunity and are taken by surprise when they're bitten," she said.
"[Patients] can get cerebral complications and lung and kidney failures if they do not get immediate treatment."
Wandiga noted that immunity to malaria develops over generations of people living with the disease.
"The second curse for highlanders who get malaria is their inability to access good medical facilities that would diagnose disease early enough and treat it," Wandiga added.
While environmental and public health experts express alarm over the effects of climate change on malaria's spread, others are still skeptical of the role of climate in the epidemics in the East African highlands.
Bob Snow is a professor at the University of Oxford based at the Kenya Medical Research Institute-Wellcome Trust Research Program. He said that rising malaria rates are more likely the result of increased drug resistance in malaria parasites and the infrequent use of pesticides in mosquito breeding grounds.
Part of the Kenyan government's strategy to control malaria includes a renewed pesticide spraying program, the distribution of more than 3.4 million mosquito nets, and the use of combined-drug therapies called ACTs, he pointed out.
"Since 2000 there has been a precipitous decline in hospitalization from malaria [that is] coincidental with expanding [mosquito] net coverage and adoption of ACTs," Snow said.
(Read related story: "Malaria Aid, Research Ramp Up to Tackle Africa Crisis" [July 21, 2005].)
Wandiga countered that the Kenyan highlands have not experienced an epidemic in the last three years because weather conditions have not been conducive to mosquito propagation.
But he said he remains concerned that the region will continue to see health effects from climate change.
"We expect the frequency of diseases to increase and hence the need for early warning and early detection systems," he added.
"We need to improve health delivery services to communities to cope with these sudden increases."
Eliza Barclay traveled to Kenya and Tanzania as a fellow with the International Reporting Project at Johns Hopkins School of Advanced International Studies.
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