Regional Update, Influenza and Other Respiratory Viruses. Epidemiological Week 34 (4 September 2026)

Regional Situation: In epidemiological week 34, influenza activity in the Region of the Americas continues to trend downward. Low levels of circulation are observed in North America. The Caribbean and Central America continue to show low activity, with positivity rates of 7.1% and 7.6%, respectively. The Andean Region shows a stable trend, with a positivity rate of 5.9%. In contrast, Brazil and the Southern Cone are experiencing a sustained decline in activity, with a positivity rate of 7.8% in EW34. Regionally, influenza B is the predominant virus, accounting for 59.5% of all influenza-positive samples. In the Caribbean and in Brazil and the Southern Cone, influenza type B is the predominant strain detected, while in Central America and the Andean Region, influenza type A is the predominant strain detected. The RSV shows a downward trend at the regional level, except for Central America and Brazil and the Southern Cone, where the positivity rate stands at 16.6% and 11.5%, respectively. Meanwhile, the circulation of SARS-CoV-2 remains stable and at low levels in most subregions, except for the Caribbean and Central America, where the positivity rate reaches 13.9% and 10.2%, respectively. Regarding other respiratory viruses, the trend is upward at the regional level, with rhinovirus being the most detected.