Influenza Update N° 518

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 Central America and the Caribbean, Tropical South America, Northern, Western and Middle Africa, Central, South and South-East Asia, and Eastern Europe. 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 (predominantly 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 (predominantly A(H3N2)) and South-East and Eastern Asia (predominantly A(H1N1)pdm09).
• In the Southern hemisphere, activity remained elevated in a few countries in Eastern Africa (predominantly A(H3N2)) and South-East Asia and multiple countries in Oceania (predominantly A(H1N1)pdm09). Overall, except in single countries in Eastern Africa and Oceania, activity remained the same or decreased.

 

SARS-CoV-2

• Globally, SARS-CoV-2 activity continued to be low across reporting countries with the exception of elevated activity reported in a few countries in Central America and the Caribbean and Temperate South America. Activity increased in single countries in Eastern Europe and Tropical South America.

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://covid.comesa.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.