Regional Update, Influenza and Other Respiratory Viruses. Epidemiological Week 45 (14 November 2025)

Regional Situation: Influenza activity in the Americas remains at low levels but shows an upward trend, with a positivity rate of 5%. RSV circulation continues to decline in the latest epidemiological week (EW), while SARS-CoV-2 shows a stable trend with a positivity rate of 7.4%. In North America, influenza activity remains at interseasonal levels with an upward trend. RSV circulation remains low with a slight upward trend, while SARS-CoV-2 decreases compared to the previous EW, with a positivity rate of 7.3%. In the Caribbean, circulation of influenza A(H1N1)pdm09 is increasing, with a positivity rate of 10.6%. RSV activity continues to rise, reaching a positivity rate of 18%, while SARS-CoV-2 is observed at low and stable levels of circulation, with a positivity rate of 2.7%. In Central America, influenza activity is increasing, with a positivity rate of 5.4%. SARS-CoV-2 remains at low and stable levels (1.2% positivity), while RSV declines this week to a positivity rate of 17.3%. In the Andean subregion, influenza A and RSV activity show a slight increase this week, reaching 4.1% and 5.2% positivity, respectively. SARS-CoV-2 decreases compared to the previous EW, presenting a positivity rate of 8.4%. In Brazil and the Southern Cone, influenza activity continues to rise (10.9% 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 (7.6% positivity). The circulation of other respiratory viruses (ORVs) remains elevated (9.2% positivity) with a downward trend at the regional level, except in the Andean subregion, which presents a positivity rate of 14% and an upward trend. The main viruses detected are Rhinovirus and Parainfluenza.