Regional Update, Influenza and Other Respiratory Viruses. Epidemiological Week 18 (15 May 2026)

Regional Situation: In epidemiological week 18, influenza activity shows mixed trends across subregions: a sustained decline in North America (6.2%), the Caribbean and Central America (8.4%), while Brazil and the Southern Cone recorded a sustained increase, reaching 10.3%, mainly associated with influenza A, with Argentina (22%), Paraguay (26%) and Bolivia (36.2%, Andean Region) among the highest values. RSV activity is moderate and increasing in the Andean Region (12%), especially in Suriname (29.2%) and Peru (13.8%), and also in Brazil and the Southern Cone (8%), while showing a decreasing trend in Chile. SARS-CoV-2 remains at low levels across all subregions. Syndromic surveillance reports increases in ILI and SARI cases mainly associated with influenza and RSV in Brazil and the Southern Cone, and the Andean Region, with a reduction in cases in North America.