Regional Update, Influenza and Other Respiratory Viruses. Epidemiological Week 42 (24 October 2025)

Regional Situation: Influenza activity in the Americas remains at low levels but shows an upward trend. RSV circulation continues to decline, and SARS_CoV-2 is also showing a downward trend during the last epidemiological week (EW), with a positivity rate of 8%. In North America, influenza activity remains at interseasonal levels. RSV circulation is low and stable, while SARS-CoV-2 decreased compared to the previous EW, with a positivity rate of 9%. In the Caribbean, influenza circulation remains low, with a positivity rate of 5.5%. RSV activity continues to rise, reaching a positivity rate of 11.8%, along with an increase in SARS-CoV-2 circulation, with a positivity rate of 6.7%. In Central America, influenza activity remains at low circulation levels, with a positivity rate of 5.3%. SARS-CoV-2 circulation decreased this week (4.2% positivity), while RSV maintains an upward trend with a positivity rate of 14.9%. In the Andean subregion, influenza A activity remains low, with a positivity rate of 5.2%. RSV decreased this week to 12% positivity, while SARS-CoV-2 increased slightly compared to the previous EW, reaching a positivity rate of 8.3%. In Brazil and the Southern Cone, influenza activity continues to rise (6.6% positivity), with circulation mainly of influenza A(H3N2). RSV circulation continues to decline, presenting a positivity rate of 1.8%, while SARS-CoV-2 remains at low levels, with a trend toward stabilization (6.1% positivity). Circulation of other respiratory viruses (ORVs) remains elevated with a decreasing trend at the regional level.