Regional Update, Influenza. Epidemiological Weeks 51-52 (11 January 2022) 

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 increased. 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. Caribbean Influenza remained at low activity levels. Haiti reported a few detections in recent weeks with the predominance of influenza B/Victoria and A(H1N1)pdm09. 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 decreased with the predominance of influenza A(H3N2) in the previous week, while influenza A(H3N2) circulation increased in Honduras with low SARI and ILI activity. Andean Overall, influenza activity remained low; however, Bolivia, Ecuador, 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 continued at extraordinary levels. Brazil and Southern Cone Influenza activity increased to pre-pandemic levels, and SARS-CoV-2 activity continues at low levels, except in Argentina. 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. Global In the temperate zones of the northern hemisphere, influenza activity, although still low, appeared to increase in some countries with detections of mainly influenza A(H3N2) and B Victoria lineage (mainly in China). In Europe, influenza activity continued to increase. Influenza A(H3N2) predominated. In East Asia, influenza activity continued rising in China, while influenza illness indicators and activity remained low in the rest of the subregion. Influenza B/Victoria viruses predominated. In tropical Africa, overall influenza activity continued decreasing, with both influenza A and B detected. In Southern Asia, influenza virus detections of predominately influenza A(H3N2) increased overall, although reducing in a few countries. In South-East Asia, sporadic influenza detections were reported in the Philippines. However, in the temperate zones of the southern hemisphere, influenza activity remained low overall. SARS-CoV-2 percent positivity from sentinel surveillance increased to approximately 30%. Activity remained under 10% positivity in the Eastern Mediterranean, South-East Asian and Western Pacific Regions of WHO. In the other WHO Regions, an increasing trend in positivity was observed in recent weeks. Overall positivity from non-sentinel sites also increased and was at 25%.