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Climate change and mosquito-borne disease expansion

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2026-10-26 13:18 UTC → 2026-10-26 21:03 UTC · added ~~removed~~

Climate change and phenomena such as El Niño continue to drive the expansion of mosquito-borne diseases and the proliferation of invasive species. Rising temperatures and altered rainfall patterns create favorable conditions for the Aedes aegypti mosquito and others, such as the tiger, Japanese, and yellow fever mosquitoes. In Brazil, health surveillance in Paranavaí reported 731 suspected and 289 confirmed dengue cases between January and early October 2026. A study by the Oswaldo Cruz Foundation (Fiocruz) indicates that climate change is driving dengue expansion across Brazil, noting that the number of microregions experiencing epidemic levels has more than doubled between 2006 and 2024, now covering 54% of the country. Thermal anomalies are identified as the primary indicator, as warming trends allow mosquitoes to thrive in previously protected regions, such as Rio Grande do Sul, which recorded nearly 210,000 confirmed infections and 281 deaths in 2024. In Bahia, approximately 163,000 cases and 188 deaths were reported. Beyond dengue, other diseases are showing increased geographic spread. Oropouche fever, once largely confined to the Amazon region, saw over 12,000 infections across 23 states last year. Additionally, extreme weather events such as floods have increased risks of waterborne diseases like leptospirosis due to contaminated water supplies. In Europe, changing climate patterns including milder winters and prolonged heat facilitate the spread of invasive mosquitoes in Spain and increase local transmission risks in Portugal. ~~In Spain, the tiger mosquito has extended its activity into late autumn and early spring.~~ Technological interventions show varying results. While the Incompatible Insect Technique (IIT) using Wolbachia bacteria has been piloted in Rome and Spain, the method has seen significant success in Balneário Camboriú, Brazil, where cases reportedly dropped from 7,106 in 2024 to just 12 in 2026.

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