Influenza Update N° 519

Overview

^{Published 20 March 2025 | For reporting Week 10, ending 09 March 2025}

Influenza

• In the Northern hemisphere, activity decreased or remained the same in most countries. Increased activity was reported in a few countries in Northern Africa, Eastern Europe, Western and South Asia. Activity remained elevated in North America and Central America and the Caribbean with co-circulation of A(H3N2) and A(H1N1)pdm09 viruses, Tropical South America (co-dominance of A(H1N1)pdm09 and A(H3N2)), Northern (predominantly A(H3N2)) and Western Africa (predominantly A(H1N1)pdm09), Europe (A and B viruses co-dominant), Central Asia (predominantly B viruses), Western and Southern Asia (co-circulation of A(H3N2) and B viruses), South-East (co-circulation of A(H1N1)pdm09 and B viruses ) and Eastern Asia (predominantly A(H1N1)pdm09).
• In the Southern hemisphere, activity remained elevated and increased in a few countries in Eastern Africa (predominantly A(H3N2)), South-East Asia, and Oceania (predominantly A(H1N1)pdm09). Overall, activity remained the same or decreased in most countries.

 

SARS-CoV-2

• Globally, SARS-CoV-2 activity continued to be low across reporting countries except for a few countries in Central America and the Caribbean and Temperate South America where elevated activity was reported. A single country in Western Africa reported increased activity.

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.