Regional Update, Influenza. Epidemiological Week 50 (28 December 2021)

ABSTRACT

[WEEKLY SUMMARY]. North America Overall, influenza activity remained low but increasing. In Canada, influenza A and B virus co-circulated with influenza A(H3N2) and A(H1N1)pdm09 among samples where subtyping was performed; SARS-CoV-2 activity slightly increased. In Mexico, influenza A(H3N2) prevailed, with B co-circulating and SARS-CoV-2 activity decreased at moderate levels. In the United States, influenza A(H3N2) predominated, with SARS-CoV-2 activity increasing, hospitalizations and deaths remained elevated. Respiratory syncytial virus activity remained high in Canada and Mexico. Caribbean Influenza remained at low activity levels. Haiti and French Guiana reported a few detections in recent weeks with the predominance of influenza B/Victoria and A(H3N2) in the latter. In Suriname, SARS-CoV-2 and SARI activity decreased to low levels. Central America Influenza activity continued low and SARS-CoV-2 activity decreased to low levels overall. In Guatemala, influenza activity increased with the predominance of influenza A(H3N2), and SARS-CoV-2 activity increased. RSV activity remained elevated in Honduras. Andean Overall, influenza activity remained low; however, Bolivia and Peru reported increased influenza activity associated with A(H3N2) detections. SARS-CoV-2 activity stands elevated in Bolivia and Ecuador, and in Bolivia, SARI activity was recorded at extraordinary levels. Brazil and Southern Cone Influenza activity increased to pre-pandemic levels, and SARS-CoV-2 activity continues at low levels. Influenza A(H3N2) detections continue to rise in Brazil, Chile, Paraguay, and Uruguay. Most activity and increasing A(H3N2) detections are recorded in Brazil and Uruguay.