What’s new: Rising temperatures and variation in the length of dry seasons appear to influence the prevalence of dengue fever, according to a recent study conducted in the Philippines.
What the study says:
- Cases of dengue fever are rising globally; in the Americas, they more than doubled from 4.6 million cases in 2023 to 10.6 million in 2024, according to the World Health Organization. In the new study, researchers wanted to find out what climate factors, including temperature and rainfall, can explain the risk of dengue infection in the Philippines.
- Using an advanced mathematical framework, the study found that temperature “consistently increased” dengue incidence throughout all the 16 regions the researchers studied. However, the effects of rainfall on cases on dengue differed depending on the variation in dry season length, “a factor previously overlooked,” the study authors write.
- The researchers found that in regions with relatively stable dry season lengths, rainfall essentially flushed out stagnant water, which tends to reduce mosquito breeding sites and in turn makes dengue transmission less likely. Meanwhile, sporadic rainfall in regions with a less predictable dry season had a weaker flushing effect and created new water pools that serve as breeding sites.
- The findings were validated when they found a similar result using data from Puerto Rico. “This consistency across different geographical regions strengthens the generalizability and reliability of our findings,” the researchers write.
What this means:
Lead author Olive R. Cawiding said in a statement that the study “represents a significant step toward understanding how climate change may impact mosquito-borne diseases globally.”
The researchers write that their methodology can also be used to better understand other climate-driven diseases like malaria, influenza, and Zika fever.
The study’s findings can “have important implications for dengue intervention strategies such as monitoring and surveillance of breeding sites, container management, and solid-waste management,” the researchers write.
The authors add that for areas where the dry season is predictable, efforts to control dengue can be scaled back to save resources. However, sustained year-round intervention is needed for regions with a less predictable dry season, they say.
Banner image of a yellow fever mosquito (Aedes aegypti) by James Gathany, Centers for Disease Control and Prevention via Wikimedia Commons (Public domain).
Credits
