Weekly update, Influenza. Epidemiological week 32 (August 26, 2022)

Imagen SE32

North America: Overall, influenza activity decreased in the subregion while SARS-CoV-2 continued elevated. In Mexico, influenza activity increased and SARS-CoV-2 positivity continued elevated; SARI activity remained at moderate-intensity levels. In the United States, influenza activity was low, with the predominance of influenza A(H3N2) virus, while SARS‑CoV-2 activity increased.

Caribbean: Overall, influenza activity remained low, with the predominance of influenza A(H3N2). The Dominican Republic and Haiti reported increased SARS-CoV-2 activity, with increased SARI activity in Haiti, with levels above average for this time of year.

Central America: Overall, influenza activity continued to decrease, with the predominance of influenza A(H3N2). In Panama, influenza activity increased to low-intensity levels, while RSV remained elevated in Nicaragua. SARS-CoV-2 activity rose across the subregion, with increased levels in Guatemala and Panama.

Andean Countries: Overall, influenza activity remained low, with A(H3N2) predominance. In Bolivia, influenza activity increased at moderate-intensity levels, while increased influenza detections were reported in Venezuela. SARS-CoV-2 activity continued to increase in Ecuador and Peru.

Brazil and Southern Cone: Overall, influenza activity remained low with influenza A(H3N2) predominance. In Chile, influenza activity continued elevated. SARS-CoV-2 activity has decreased throughout the subregion, although it increased in Chile and Argentina. In Uruguay, SARI activity was elevated above epidemic levels for the period, and RSV predominated. ILI activity continued increased in Chile at moderate-intensity levels.

Global: Influenza activity has steadily decreased from a peak in March 2022, except in Southeast Asia, where influenza activity increased. In the temperate zones of the southern hemisphere, overall influenza activity appeared to decrease during this reporting period. In Oceania, detections of primarily influenza A(H3N2) decreased overall, and influenza-like illness (ILI) activity returned to low levels in most Pacific Island countries. In Southern Africa, influenza activity decreased in general with continued detections of influenza A(H1N1)pdm09, influenza A(H3N2), and a few influenza B viruses. In tropical Africa, influenza activity decreased with influenza A(H3N2) viruses predominant among the reported detections. In Southern Asia, influenza detections of predominantly A(H3N2) viruses decreased while detections of influenza A(H1N1)pdm09 increased in recent weeks, especially in India. In South-East Asia, influenza activity increased overall with predominantly detected influenza A(H3N2) viruses. In Europe, influenza activity remained at inter-seasonal levels, with influenza A(H3N2) predominant among the subtyped viruses. In Central Asia and Northern Africa, no influenza detections were reported. In East Asia, influenza activity of predominantly influenza A(H3N2) seemed to have peaked in the southern provinces of China. Elsewhere, influenza illness indicators and activity remained low. In Western Asia, low numbers of detections of influenza A(H1N1)pdm09, A(H3N2), and B viruses were reported.

COVID-19 positivity from sentinel surveillance continued to decrease and was at approximately 40% in the reporting period. The highest positivity rate was reported in the Americas, while the other regions remained below 20%. Activity from non- sentinel sites remained stable, with overall positivity around 40%.