Researchers from the London School of Hygiene and Tropical Medicine and the University of Michigan sifted through regional records in Ethiopia and Colombia, two tropical countries with highland territory, looking at malaria cases from 1990 to 2005 in Colombia and 1993 to 2005 in Ethiopia. They corrected for other factors that might influence malaria cases—mosquito control programs, for example, which lead to fewer of the insects; and rainfall, which leads to more—and found that the median altitude of malaria cases moved higher in warm years, and lower during cooler yields. Prof Mercedes Pascual, from the University of Michigan in the US, who carried out the research, said: "The impact in terms of increasing the risk of exposure to disease is very large." In an earlier paper, the Science researchers estimated that a 1° C (1.8° F) temperature increase could lead to an additional 3 million malaria cases in Ethiopian children, assuming control methods weren't strengthened.
– Efforts to eradicate malaria are going to be hit hard by rising temperatures that open up new altitudes to the mosquitoes that carry the disease, researchers warn. Both mosquitoes and the malaria parasite struggle in chillier temperatures, and a new study has found that the disease climbs to higher elevations in warmer years, the BBC reports. In areas like the highlands of Colombia and Ethiopia, people have never been exposed to malaria, making them especially vulnerable to the spread of the disease. "We have estimated that, based on the distribution of malaria with altitude, a 1C rise in temperature could lead to an additional three million cases in under-15-year-olds per year," one of the researchers warns. Malaria infects more than 200 million people per year and kills around 600,000 of them, mainly children in Africa. But climate isn't the only factor at work in its spread, with the biggest advances in malaria control coming alongside efforts to combat poverty, Time notes.