Regional Update, Influenza and Other Respiratory Viruses. Epidemiological Week 12 (3 April 2026)

Regional Situation: Influenza activity in the Northern Hemisphere of the Americas decreased compared with the previous epidemiological week (EW). However, sustained activity persists, driven by increased circulation of influenza B in North America, where influenza B has replaced influenza A as the predominant virus over the past four weeks. In the rest of the region, influenza activity varies across subregions, ranging from low to epidemic levels, with influenza A(H3N2) as the predominant virus. Overall, respiratory syncytial virus (RSV) circulation has remained stable over the past two months, with a positivity of 2%. SARS-CoV-2 circulation decreased, reaching a positivity of 3.7%. Circulation of other respiratory viruses (ORV) continues to increase, reaching a regional positivity of 3.2%, mainly driven by seasonal coronaviruses.