Weekly updates, Influenza Epidemiological Week 7 (24 February 2023)

North America: Influenza activity was low in the subregion. Influenza A virus predominated, with co-circulating A(H3N2) and A(H1N1)pdm09. All influenza B viruses with determined lineage were B/Victoria. The SARS-CoV-2 and RSV activity decreased in the subregion. In Canada, influenza activity decreased overall, with A(H1N1)pdm09 predominance. In Mexico, influenza activity was low, while SARS-CoV-2 and RSV activity remained elevated. In the United States, influenza activity was low nationally. 

Caribbean: Influenza activity was elevated with a decreasing trend. Influenza A and B viruses were equally detected. Influenza A(H1N1)pdm09, A(H3N2) and influenza B/Victoria co-circulated. In French Guyana, influenza activity was elevated but decreasing. SARS-CoV-2 activity was low in the subregion, with RSV activity at baseline levels except in Jamaica, where RSV activity was increased. 

Central America: Influenza activity was moderate, with the circulation of influenza B/Victoria virus. No influenza A virus detections were reported. Guatemala reported increased influenza activity with influenza B/Victoria circulation; severity indicators were at baseline levels. El Salvador and Honduras reported increased influenza activity at moderate-intensity levels; severity indicators were at baseline levels. SARS-CoV-2 percent positivity decreased in the subregion, except in Costa Rica and Panama. RSV activity remained elevated in Guatemala but is decreasing. 

Andean: Influenza activity was low, predominating influenza B/Victoria viruses; influenza A(H3N2) and A(H1N1)pdm09 viruses co-circulated. In Bolivia, influenza activity was elevated with B/Victoria circulation and SARI cases at moderate-intensity levels, with 50% of sampled cases positive for influenza. Ecuador reported increased influenza activity at a low-intensity level; severity indicators were at low-intensity levels. SARS-CoV-2 activity was elevated in Ecuador and Peru. In the subregion, RSV activity was low overall. 

Brazil and Southern Cone: Influenza activity was low, with influenza B viruses more frequently detected and co-circulated B/Victoria and A(H1N1)pdm09. In Paraguay, influenza activity was elevated at a low-intensity level, with influenza B (lineage undetermined) circulating; severity indicators were low. SARS-CoV-2 activity was low, except in Brazil and Chile, while RSV activity remains elevated in Brazil. 

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 | Pan American Health Organization (paho.org)