Regional Update, Influenza and Other Respiratory Viruses. Epidemiological Week 43 (6 November 2026)

Regional situation: In EW 43, influenza activity is increasing in North America, with A(H1N1)pdm09 predominating, and remains elevated in the Caribbean. In Central America and the Andean Subregion it stands at around 11–12%, with recent increases in El Salvador, Panama, Ecuador and Peru. In Brazil and the Southern Cone it remains below 10%, with an increase in Argentina. Influenza B predominates in the Andean Subregion, in Brazil and the Southern Cone, in Mexico and in El Salvador. In Central America influenza A(H3N2) predominates, with a growing proportion of influenza B. RSV is increasing in Mexico, the Caribbean and Panama, and continues to decline in the Andean Subregion and in Brazil and the Southern Cone. Even so, it remains the main virus identified in SARI cases in North America, the Caribbean and Brazil and the Southern Cone. SARS-CoV-2 circulation is low across all subregions, although it predominates among ILI detections in Brazil and the Southern Cone. Positivity for other respiratory viruses remains elevated in Brazil and the Southern Cone, above previous seasons, with rhinovirus and metapneumovirus predominating. SARI cases show a downward trend in Brazil and the Southern Cone and in the Andean Subregion, and a slight increase in the Caribbean and Mexico. Data for the last two weeks are preliminary and may change due to late reporting.