A recent study done in the Philippines found that the prevalence of dengue fever appears to be influenced by rising temperatures and variations in the length of dry seasons.

• According to the World Health Organization, dengue fever cases are increasing worldwide; in the Americas, they more than doubled from 4.6 million in 2023 to 10.6 million in 2024. The goal of the recent study was to determine which climate variables—such as rainfall and temperature—can account for the risk of dengue infection in the Philippines.
• Using a sophisticated statistical framework, the study discovered that in each of the 16 regions they examined, temperature “consistently enhanced” the prevalence of dengue. However, the authors of the study note that the impact of rainfall on dengue infections varied according on the length of the dry season, “a factor hitherto neglected.”
• The researchers discovered that rainfall effectively swept off stagnant water in areas with comparatively consistent dry season lengths, which tends to decrease mosquito breeding sites and, consequently, dengue transmission. In contrast, intermittent rainfall produced new water pools that act as breeding grounds and had a less effective flushing impact in areas with an unpredictable dry season.
• When they discovered a comparable outcome using data from Puerto Rico, the conclusions were confirmed. The researchers state that “this uniformity across diverse geographical regions increases the generalizability and trustworthiness of our findings.”

Summary

The study “represents a critical step toward understanding how climate change may effect mosquito-borne diseases globally.”

Other climate-driven illnesses including influenza, Zika fever, and malaria can also be better understood by applying their methods.

The study’s conclusions may “have substantial consequences for dengue intervention measures such as monitoring and surveillance of breeding locations, container management, and solid-waste management.”

Dengue management measures can be lowered in regions with a known dry season in order to conserve resources. However, they assert that areas with a less predictable dry season require consistent year-round management.

Abstract