PAHO, Risk of DENV-3 outbreaks in the Americas

The Pan American Health Organization (PAHO) has issued an epidemiological alert on the increased risk of dengue outbreaks in the Americas due to the increased circulation of the DENV-3 serotype in a number of Latin American countries. The DENV-3 serotype has been identified in Brazil, Colombia, Costa Rica, Guatemala, Mexico and Peru. Argentina documented its circulation in the country in 2024. Brazil and Colombia have seen an increase in DENV-3-associated cases, particularly in children. The virus was also detected in other countries in Central America and the Caribbean. In the first weeks of 2025, 23 countries and territories in the Region recorded a total of 238,659 dengue cases, with the majority (87%) reported in Brazil, followed by Colombia (5.6%), Nicaragua (2.5%), Peru (2.5%) and Mexico (2.5%). Of these, 23 deaths were recorded. The DENV-3 serotype has been associated with severe disease manifestations, even in primary infections, raising concerns about its potential public health impact. The re-emergence of this serotype after a long absence from certain regions of the continent underscores the vulnerability of populations not previously exposed, especially in the context of increased susceptibility. PAHO has issued a call to action to member countries, emphasizing the urgent need to strengthen surveillance, prompt detection, and effective clinical management strategies to mitigate any increase in dengue cases.