Climate change is having a global impact on dengue transmission, accounting for 19 percent of the current dengue burden. Human climate activity has the potential to spark an additional 40-to-60 percent spike by 2050.
These warnings are based on a new study presented at the Annual Meeting of the American Society of Tropical Medicine and Hygiene (ASTMH), based on findings from researchers at Stanford and Harvard Universities.
Countries in the Americas alone have recorded almost 12 million cases in 2024 compared to 4.6 million in 2023, and locally acquired infections have been reported in California and Florida.
According to lead researcher Erin Mordecai: “We looked at data on dengue incidence and climate variation across 21 countries in Asia and the Americas and found that there is a clear and direct relationship between rising temperatures and rising infections. “It’s evidence that climate change already has become a significant threat to human health and, for dengue in particular, our data suggests the impact could get much worse.”
Some dengue infections produce mild symptoms, others cause excruciating joint pain, and severe cases can lead to bleeding complications and shock. There are no drugs to treat the disease.
While there are two licensed dengue vaccines available, some dengue experts have pointed to challenges with both that could limit widespread adoption.
The study finds that moderating global warming by reducing emissions would also moderate climate impacts on dengue infections.
Global climate models predict that temperatures will continue to increase even with large reductions in emissions, hence 17 of the 21 countries studied would see climate-driven increases in dengue even under the most optimistic scenarios for carbon cuts.
The study further found that there are at least 257 million people now living in places where climate warming could cause dengue incidence to double in the next 25 years.
Mordecai said the study probably underestimates the climate-related dengue threat, meaning that urgent action is required by the government’s of the world.
