Influenza Update N° 509

Overview

^{Published 15 January 2025 | For reporting Week 1, ending 05 January 2025}

Influenza

• In the Northern hemisphere, influenza activity was elevated and increased in many countries in Europe (mostly A(H1N1)pdm09 detected, with A(H3N2) more common in Eastern Europe), North America (A(H1N1)pdm09 and A(H3N2) co-circulating), Central America and the Caribbean (mostly A(H3N2)), Western Africa (mostly A(H1N1)pdm09 and B viruses), Middle Africa (mostly A(H1N1)pdm09), Northern Africa (mostly A(H3N2)), and in many countries across Asia (mostly A(H1N1)pdm09).
• In the Southern hemisphere, influenza activity was elevated in a few countries in Tropical South America (A(H3N2) and B viruses co-circulating), Eastern Africa (mostly B viruses), and Melanesia (mostly A(H1N1)pdm09). Activity was similar or declined in all reporting countries.

 

SARS-CoV-2

• SARS-CoV-2 activity was elevated in parts of South America, Eastern Africa, and Southern and South East Asia. Increased activity was reported from single countries in Central America and in Southern Asia but was similar or declined in all other reporting countries.

WHO encourages countries, especially those that have received the multiplex influenza and SARS-CoV-2 reagent kits from GISRS, to conduct integrated surveillance of influenza and SARS-CoV-2 and report epidemiological and laboratory information in a timely manner to established regional and global platforms. The guidance can be found here https://www.who.int/publications/i/item/WHO-2019-nCoV-integrated_sentinel_surveillance-2022.1.
 

Starting with report #501, the Global Respiratory Virus Activity Weekly Update included data from sentinel surveillance and other types of systematically conducted virologic surveillance. Countries, areas, and territories use a variety of approaches to monitor respiratory virus activity and data in this report may vary from surveillance reports posted elsewhere. Analyses stratified by source of surveillance is available through Respimart.