Ambient PM₂.₅ exposure and increased dengue case fatality: a global multi-country analysis

Area of Science:

• Environmental Health
• Epidemiology
• Vector-borne Diseases

Background:

• Dengue is a growing global health threat, sensitive to climate and environmental factors.
• The impact of air pollution, specifically fine particulate matter (PM2.5), on dengue severity is not well understood.

Purpose of the Study:

• To investigate the association between long-term exposure to ambient PM2.5 and dengue case fatality rates (CFRs) in endemic countries.
• To assess the role of PM2.5 as a predictor of dengue mortality across different socioeconomic and climatic contexts.

Main Methods:

• A multi-country ecological study involving 20 dengue-endemic nations from 2020-2024.
• Integration of national dengue surveillance data with satellite-derived PM2.5 estimates and socioeconomic-climatic data.
• Generalized linear mixed-effects models were used to analyze the association between PM2.5 exposure and dengue CFRs.

Main Results:

• Countries with PM2.5 levels exceeding 35 μg/m³ exhibited 3-5 times higher dengue CFRs compared to those below 15 μg/m³.
• PM2.5 concentration was an independent predictor of dengue mortality, with each unit increase associated with a 94% higher risk of death.
• Higher GDP per capita showed a protective effect against dengue mortality.

Conclusions:

• This study presents multi-continental evidence linking higher ambient PM2.5 exposure to increased dengue mortality.
• The findings highlight global environmental injustice, with high PM2.5 exposure and low GDP converging in vulnerable regions.
• Integrating air quality management into dengue control strategies may offer significant co-benefits for public and environmental health.