A new study has revealed direct evidence that higher temperatures caused by climate change are significantly increasing dengue infections across Asia and the Americas. The research, published in the Proceedings of the National Academy of Sciences, found that climate change was responsible for an estimated 18% of dengue cases in 21 countries between 1995 and 2014, with projections indicating a substantial rise in future infections.
Quantifying Climatell Role in Disease Spread
Dengue is a mosquito-borne disease transmitted by the Aedes aegypti mosquito. While previous studies have pointed to a link between rising temperatures and the expansion of the mosquito’s habitat, this is the first time scientists have directly quantified climate change’s contribution to the disease’s spread.
The findings suggest that warming weather has caused over 4.6 million additional dengue cases annually in the studied regions. Researchers noted that these numbers are conservative, as they do not include large endemic areas like India and parts of Africa where data is limited.
The study confirmed that dengue transmission thrives in a “Goldilocks zone” of temperatures, peaking at about 27.8°C (82°F). As cooler, high-population regions like Mexico, Peru, and Brazil warm, they are moving into this optimal range, leading to a projected spike in cases. In contrast, a few already-hot lowland areas may see a slight decline as temperatures exceed the optimal range.
Future Projections and Mitigation
The research warns that dengue cases could increase by another 49% to 76% by mid-century, with incidence more than doubling in many cooler locations that are home to over 260 million people.
According to Marissa Childs, the lead author of the study, even small shifts in temperature can have a major impact on dengue transmission, and the “fingerprint of climate warming” is already visible. The study highlights that urbanisation, human migration, and the evolution of the dengue virus will further exacerbate these risks. To combat this growing threat, the researchers stress that aggressive climate mitigation, better mosquito control, and the strengthening of public health systems with new vaccines are essential.