Regional Update, Influenza and Other Respiratory Viruses. Epidemiological Week 3 (30 January 2026)

Regional Situation: Influenza activity in the Americas has shown a sustained decline since peaking at the end of 2025, with a regional positivity of 14.1%. Influenza A(H3N2) continues to predominate among subtyped samples in all regions, except in the Andean subregion. RSV circulation has increased rapidly, rising from 1.1% in the previous week to 2.8%, mainly driven by increased activity in North America. SARS-CoV-2 positivity is stable at 5.4%. In North America, influenza activity continues to decline, with a positivity of 14.8%. RSV circulation remains low, but with a sharp increase, rising from 1.0% to 3.0%, while SARSCoV-2 positivity remains stable at 5.4%. In the Caribbean, influenza and RSV activity are decreasing, following a period of intense activity, with a positivity of 16.4% and 3.4%, respectively. SARS-CoV-2 circulation remained low and stable. In Central America, influenza activity continues to increase, reaching a positivity of 61.4%. SARS-CoV-2 circulation remained low and stable (<1%), while RSV activity remained elevated at 2.4%. In the Andean subregion, influenza activity increased over the past four epidemiological weeks (EWs), reaching a positivity of 17.9%. RSV circulation also increased, reaching a positivity of 3.6%. SARSCoV-2 circulation decreased over the past three EWs, with a positivity of 1.2%. In Brazil and the Southern Cone, influenza activitydecreased compared with the previous EW, with a positivity of 2.7%. RSV circulation remains at interseasonal levels (<1%), while SARS-CoV-2 activity decreased to a positivity of 7.9%. Circulation of other respiratory viruses (ORVs) increased after a sustained decline since early October, with a regional positivity of 2.0%. Rhinovirus and parainfluenza remain the most frequently detected ORVs.