Weekly updates, Influenza Epidemiological Week 21 (1 June 2023)

North America: Influenza activity has remained at low levels. During the last 4 EW, the predominant influenza viruses have been B/Victoria, with also circulation of influenza A (mostly A(H1N1)pdm09) at a lesser extent. Respiratory Syncytial Virus (RSV) activity has remained at low levels. SARS-CoV-2 activity has decreased however it continues circulating at moderate levels. SARI and ILI cases showed a decreasing trend, being most cases due to SARS-CoV-2.

Caribbean: Influenza activity has shown a decreasing trend. During the last 4 EW, the predominant influenza viruses have been B/Victoria, with less circulation of influenza A (mostly A(H1N1)pdm09). RSV activity has remained low. SARS-CoV-2 activity has shown an increase in the past 4 EWs circulating at moderate levels. SARI activity has shown a decreasing trend, with most cases related to influenza and ILI activity has shown a slight increase due to SARS-CoV-2 positive cases.

Caribe: La actividad de la influenza ha mostrado una tendencia decreciente. Durante las últimas 4 semanas epidemiológicas, los virus predominantes de la influenza han sido B/Victoria, con menor circulación de la influenza A (principalmente A(H1N1)pdm09). La actividad del VSR ha permanecido baja. La actividad del SARS-CoV-2 ha mostrado un incremento en las últimas 4 SE y actualmente se encuentra en niveles intermediosde circulación. Los casos de IRAG han mostrado una tendencia decreciente, siendo la mayoría asociados a influenza y la actividad de ETI ha mostrado un ligero incremento debido a casos SARS-CoV-2 positivos.

Central America: Influenza activity has shown an increase in the past 4 EWs with high levels of circulation. During the last 4 EW, the predominant influenza viruses have been A, mostly A(H1N1)pdm09, with co-circulation on influenza A(H3N2) and influenza B/Victoria. RSV activity has remained low. SARS-CoV-2 activity has remained low and has decreased in recent weeks. SARI and ILI activity has remained low, with most cases related to influenza.

Andean: Influenza activity has shown a decrease in the past 4 EW although the number of detections continued to be high. During the last 4 EW, the predominant influenza viruses have been influenza A, mostly A(H1N1)pdm09, with less circulation of influenza B /Victoria. RSV activity remained at medium levels of circulation. SARS-CoV-2 has circulated at moderate levels. SARI activity has shown an increase in the last EW, with influenza and SARS-CoV-2 accounting for the majority of the cases. ILI activity has shown a decreasing trend with most cases related to influenza.

Brazil and Southern Cone: Influenza activity remains at moderate levels of circulation. During the last 4 EW, the predominant influenza viruses have been A, mostly A(H1N1)pdm09, with co-circulation of influenza B/Victoria. RSV activity has remained steady in the last 4 EWs at moderate levels. SARS-CoV-2activity has remained at low levels. After reaching high levels, SARI and ILI activity has exhibited a decline over the past four EWs, primarily attributed to cases linked to RSV and influenza.