Regional Update, Influenza and Other Respiratory Viruses. Epidemiological Week 33 (22 August 2025)

Regional Situation: Influenza activity in the Americas continues to decline. SARS-CoV-2 activity shows a slight increase. For RSV, regional circulation displays an upward trend. In North America, influenza activity remains at interseasonal levels. In the Caribbean, circulation is decreasing, with a positivity rate of 6.3%. Subtype A(H1N1)pdm09 continues to be predominant. RSV activity remains low and stable in North America, while in the Caribbean it continues to rise, reaching a positivity rate of 9.6% in the latest epidemiological week (EW). SARS-CoV-2 activity is increasing in both North America and the Caribbean, where positivity reached 5.3% and 20.1%, respectively. In Central America, influenza activity remains elevated but shows a downward trend, with a positivity rate of 8.9%. SARS-CoV-2 activity decreased this week, with a positivity rate of 5.8%, while RSV increased again, reaching a positivity rate of 12.6%. In the Andean subregion, influenza A activity continues its downward trend, with a positivity rate of 7.8%. RSV activity remains high, with a stable trend and a positivity rate of 10.3%, while SARS-CoV-2 circulation remains unchanged compared to the previous week. In Brazil and the Southern Cone, influenza activity continues to decline, with a positivity rate of 3.1%. RSV circulation decreased compared to the previous EW, with a positivity rate of 13.7%, while SARS-CoV-2 activity remains at low levels.