Global warming increases malaria risk in higher-altitude areas

Global warming magnifies the risk for malaria for those living in regions of higher altitudes, a study in the US journal Science said Thursday. People living in tropical highland areas in Africa, Asia and central and southern America are especially prone to the climate-related health perils.

Malaria killed about 620,000 people in 2012 alone, and climate change will only make the numbers go higher.

In Ethiopia alone, "a one-degree-Celsius increase in temperature will lift the area where malaria can occur by 150 meters," Menno Bouma of the London School of Hygiene and Tropical Medicine told the Associated Free Press.

Bouma added that other tropical highland areas surrounded by malaria-endemic regions, but that have not built up immunity to the disease, will be particularly vulnerable. This includes parts of Peru, Ecuador, Kenya, Uganda, Tanzania, Madagascar, Pakistan, India, Nepal and Papua New Guinea.

By looking at malaria records from the highland regions of Colombia and Ethiopia specifically, the study's team found that people living in these areas had more malaria infections during the warmer years than the cooler years.

"This is indisputable evidence of a climate effect," said University of Michigan ecologist Mercedes Pascual.

But Bouma notes that the study did not automatically imply a higher malaria risk for all countries at higher altitudes. Other factors like certain climate and socio-economic conditions also had to be present.

Malaria is caused by a parasite transmitted through mosquito bites, and can be prevented with nets, insecticides and medicines. Symptoms can include fever, headache, and vomiting. It can disrupt the blood supply to vital organs, and so is fatal if left untreated.

However, malaria is not the only disease to watch out for as temperatures rises.

"Many of the major killers such as diarrheal diseases, malnutrition, malaria and dengue are highly climate-sensitive and are expected to worsen as the climate changes," according to the World Health Organization (WHO).