Regional Update, Influenza and Other Respiratory Viruses. Epidemiological Week 44 (7 November 2025)

Regional Situation: Influenza activity in the Americas remains at low levels, but with an upward trend and a positivity rate of 4.5%. Circulation of RSV and SARS-CoV-2 continues to decline in the latest epidemiological week (EW). In North America, influenza activity remains at interseasonal levels with a slight upward trend. RSV circulation remains low, while SARS-CoV-2 decreases compared to the previous EW, with a positivity rate of 7.6%. In the Caribbean, circulation of influenza A(H1N1)pdm09 is increasing, with a positivity rate of 9.5%. RSV activity continues to rise, reaching a positivity rate of 17.4%, while SARS-CoV-2 shows stable circulation levels and a positivity rate of 3.2%. In Central America, influenza activity remains at low circulation levels, with a positivity rate of 3.8%. SARS-CoV-2 circulation decreases this week (1.6% positivity), while RSV continues its upward trend with a positivity rate of 18.7%. In the Andean subregion, influenza A activity remains low with a positivity rate of 3.6%. RSV decreases this week to a positivity rate of 4.3%, while SARS-CoV-2 increases compared to the previous EW, presenting a positivity rate of 10%. In Brazil and the Southern Cone, influenza activity continues to rise (9.8% positivity), with predominant circulation of influenza A(H3N2) and influenza B. RSV circulation reaches interseasonal levels, while SARS-CoV-2 is observed at low levels with an upward trend (6.4% positivity). Circulation of other respiratory viruses (ORV) remains elevated (9.9% positivity) with a regional trend toward decline.