Malarial mosquitoes found on Mt. Kenya for first time ever, thanks to climate change

The ecology of malaria is such that there is no easy equation between any one factor and malaria transmission. This is especially true for climatic changes. More rain can mean more malaria – or less. (For example, rainfall can wash away mosquito larvae, or alternatively can create new mosquito larval sites.) Heat can result in more malaria – or not. (England was malarious during the little Ice Age.) What does seem predictable is that as the climate changes in malarial areas, the ecology of malaria will change with it, one way or another.

Snow cover is receding on both Mount Kenya (the highest peak in Kenya and the second highest peak in Africa) and Mount Kilimanjaro (at 17,000-feet, the highest peak in Africa.) Researchers at the Kenya Medical Research Institute report that malarial mosquitoes have been found on the slopes of Mount Kenya for the first time ever, and attribute their presence to regional warming due to global climate change.

According to the institute, malaria prevalence in the Western Highlands of Kenya could rise by up to 80 percent.

Researchers believe that these highlands have been historically malaria-free, save for the odd introduced and imported cases, because malarial mosquitoes have never been found in the region, until now. With Anopheles arabiensis in place, and a steady influx of imported cases, local transmission is now possible. The non-immune locals, as well as the 15,000 tourists who arrive every year to experience the mountains, will be especially vulnerable.

For more:

Hong Chen et al, “New records of Anopheles arabiensis breeding on the Mount Kenya highlands indicate indigenous malaria transmission,” Malaria Journal, March 7, 2006

http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1420308

Harold Ayodo, “Malaria infections on the rise,” The Standard, October 5, 2006