Dengue fever could soon spread to South America's high Andes region and other parts of the world currently free of the disease, according to new research published Monday.
“Changes to climate could result in increased exposure and pose a serious threat to areas that do not currently experience endemic dengue,” warned a report from the United Nations University.
Large areas of South America's mountainous regions have historically been either low risk for dengue fever, or free of the disease entirely.
In the Western Hemisphere, dengue is widespread across lowland areas of Mexico, Central America, northern countries of South America, and parts of the Caribbean. Over 2 million cases of the disease are reported annually across the Americas, mostly in low lying tropical areas.
Many Latin American countries have doubled down on dengue prevention measures in recent years. While the Venezuelan government has invested millions of dollars in new medical equipment and spraying efforts in recent months, Brazil is using mosquitoes carrying an anti-dengue bacteria to control the disease.
However, the research suggests the Andes isn't the only region where dengue could spread in the coming years.
According to the university's study, a warmer climate will spur dengue to spread further north and south of the equator.
“Conditions in West and Central Africa are particularly favorable for expansion of dengue illness and both regions are urged to plan for this anticipated health challenge,” the report warned.
Dengue is a mosquito borne disease that kills close to 20,000 people every year. At any given time around 400 million people are suffering from the disease, with most cases in tropical climates were the vector – the Aedes Aegypti mosquito – is found.
“In typical northern conditions, eggs of the dengue-carrying Aedes mosquitoes die below -2°C. Should minimum temperatures rise 2°C and 4°C due to climate change, however, the eggs could survive, putting large populations worldwide at risk of exposure for the first time,” the paper explained.
According to the university, by 2085 between 5-6 billion people could be at risk of contracting the disease. Currently, that figure is closer to 2.5 billion.
“The increase due to climate change alone would more than double the number at those at risk to an estimated 3.5 billion,” the report warned.