Regional Update, Influenza and Other Respiratory Viruses. Epidemiological Week 1 (6 January 2023)

ABSTRACT

[WEEKLY SUMMARY]. North America Influenza activity was moderate and declining in the subregion, with the predominance of influenza A(H3N2) and co-circulation of A(H1N1)pdm09 and B/Victoria. The SARS-CoV-2 activity has increased, while RSV activity continued to decrease. In Canada, influenza activity has decreased; most surveillance indicators were within expected levels. In Mexico, influenza activity continued above expected levels; severity indicators were low. In the United States, influenza activity declined at low-intensity levels, with the percentage of deaths due to pneumonia, influenza, and COVID-19 above the average of previous seasons. RSV activity continued decreasing. Caribbean Influenza activity was moderate in the subregion with A(H3N2) virus predominance, A(H1N1)pdm09, and B/Victoria co-circulated. Influenza percent positivity increased in Belize and Haiti. SARS-CoV-2 activity remained low overall; however, Belize, Haiti, and Jamaica reported increased COVID-19 activity. In addition, RSV activity was increased in Jamaica. Central America Influenza activity was at moderate levels, with the predominance of influenza A(H3N2) and the co-circulation of influenza A(H1N1)pdm09 and B/Victoria (where lineage was determined). Influenza activity was elevated in Honduras, with the circulation of influenza B (lineage undetermined). SARS-CoV-2 percent positivity decreased in the subregion, with an increased percent positive in Costa Rica, Guatemala, and Honduras. In addition, Guatemala reported increased RSV activity. Andean Influenza activity was low but increasing, with the predominance of influenza A(H3N2) and co-circulation of influenza A(H1N1)pdm09 and B/Victoria. Influenza activity was elevated in Bolivia and Ecuador, with increased SARI activity at low-intensity levels in both countries. In addition, SARS-CoV-2 percent positivity increased in Colombia, Ecuador, and Peru. In the subregion, RSV activity was low overall, with an increasing trend. Brazil and Southern Cone Influenza activity decreased to low levels, with influenza A(H3N2) predominance and co-circulation of influenza A(H1N1)pdm09 and influenza B/Victoria. Argentina and Chile reported declining influenza activity. SARS-CoV-2 activity was elevated across the subregion but with a decreasing trend. Increased RSV activity continued to be reported in Brazil and Chile. Avian Influenza A summary of the avian influenza situation in the region, case management and recommendations are available at Epidemiological alerts and updates | PAHO/WHO | Panamerican Health Organization (paho.org)