Regional Update, Influenza and Other Respiratory Viruses. Epidemiological Week 18 (9 May 2025)

Regional Situation: In general, North America and parts of the Caribbean continue to see a decline in influenza activity, mainly associated with influenza A(H1N1)pdm09 and influenza B. RSV activity remains at interseasonal levels in North America, and after an increase in the Caribbean, it is now beginning to decline again. SARS-CoV-2 activity remains low. In Central America, the circulation of influenza A(H1N1)pdm09 has decreased compared to the previous epidemiological week (EW), with a positivity rate of 18.8%. RSV and SARS-CoV-2 activity remain low. The Andean subregion shows a decline in SARS-CoV-2 circulation and a decreasing trend in influenza A(H3N2), while RSV is on the rise, with a positivity rate of 10.0%. Brazil/Southern Cone continues its upward trend in influenza A(H1N1)pdm09, with a positivity rate of 17.2%. SARS-CoV-2 continues to decline, while RSV shows an increasing trend, with a positivity rate of 2.87%. Across the region, there is a high percentage (9.2%) of detections of other respiratory viruses (ORV), with rhinovirus standing out in North America, as well as in Brazil and the Southern Cone. Parainfluenza circulation has been detected in the Caribbean.