Dengue-transmitting mosquito found in 28 Portuguese municipalities

Tuesday, 28 April 2026AI summary

The Aedes albopictus mosquito, known for transmitting diseases like dengue and Zika, has expanded its presence to 28 municipalities across Portugal, an increase of ten from 2024. Recent data from the National Institute of Health Dr. Ricardo Jorge (Instituto Nacional de Saúde Doutor Ricardo Jorge or INSA) confirms new detections in Lisbon, Oeiras, Almada, and Sesimbra.

Context & Explainers

Excess mortality is the number of deaths above what would be expected based on historical averages (commonly a multi‑year baseline), and it captures deaths directly and indirectly caused by events like epidemics, heatwaves or healthcare disruptions. Portugal’s public health institute INSA (Instituto Nacional de Saúde Doutor Ricardo Jorge) monitors excess mortality to see the broader impact of seasonal illnesses and other stresses on the health system, so a drop in flu cases does not automatically mean overall mortality has returned to normal. Those following public‑health trends should note excess‑mortality figures because they show the pandemic and other factors’ continuing effect on population health.