Climate change is responsible for nearly a fifth of the record number of dengue cases worldwide this year, US researchers said on Saturday, seeking to shine a light on how rising temperatures help spread disease. Researchers have been working to swiftly demonstrate how human-driven climate change directly contributes to individual extreme weather events such as the hurricanes, fires, droughts and floods that have battered the world this year. But linking how global warming affects health—such as driving outbreaks or spreading disease—remains a new field.
"Dengue is a really good first disease to focus on because it's very climate sensitive," Erin Mordecai, an infectious disease ecologist at Stanford University, told AFP. The viral disease, which is transmitted via bites from infected mosquitoes, causes fever and body aches and can, in some cases, be deadly. It has typically been confined to tropical and sub-tropical areas but rising temperatures have led to mosquitoes encroaching on new areas, taking dengue with them.
For the new study, which has not yet been peer-reviewed, a US team of researchers looked at how hotter temperatures were linked to dengue infections in 21 countries across Asia and the Americas. On average, around 19 percent of current dengue cases around the world are "attributable to climate warming that has already happened", said Mordecai, the senior author of the pre-print study. Temperatures between 20-29 degrees Celsius (68-84 degrees Fahrenheit) are .