A study published in Science Advances has confirmed that temperature and rainfall are key factors influencing the spread of dengue fever. Researchers analysed data to understand how climate variations impact mosquito populations and disease transmission.
According to the World Health Organisation (WHO), dengue cases increased from 4.1 million in 2023 to over 10.6 million in 2024 in the Americas. The European Centre for Disease Prevention and Control reported over 14 million cases and more than 10,000 deaths globally in 2024.
While it is known that rainfall affects mosquito breeding, its exact impact on dengue transmission remains debated. Some researchers suggest rainfall increases disease spread, while others argue it suppresses mosquito populations by flushing out breeding sites.
Scientists at the Institute for Basic Science (IBS) developed a method to assess the relationship between climate and dengue incidence. The study was conducted in the Philippines and Puerto Rico to account for different climatic conditions.
The study found that rising temperatures lead to an increase in dengue cases. In eastern regions, higher rainfall also contributed to a rise in cases, while in western areas, rainfall suppressed mosquito populations by washing away breeding grounds.
Researchers found that longer dry seasons led to more mosquito breeding, increasing dengue transmission. In contrast, shorter dry seasons resulted in fewer mosquitoes due to natural environmental conditions.
The study suggests targeted intervention strategies based on regional climate patterns. Areas with long dry seasons require year-round mosquito control, while regions with short dry seasons may benefit from natural rainfall effects. These findings also apply to other mosquito-borne diseases such as malaria, influenza, and Zika virus.