Influenza Update N° 516

Overview

^{Published 06 March 2025 | For reporting Week 8, ending 23 February 2025}

Influenza

• In the Northern hemisphere, activity remained elevated in North America (predominantly A(H1N1)pdm09), Central America and Caribbean (predominantly both influenza A subtypes), Tropical South America (predominantly A(H1N1)pdm09 and B), Northern (predominantly both influenza A subtypes), Western (predominantly A(H1N1)pdm09) and Eastern Africa (predominantly A(H3N2) and B), all of Europe (Northern: both influenza A subtypes, elsewhere: all seasonal subtypes); Western (predominantly A(H3N2)), Southern (all seasonal subtypes), South-East (predominantly A(H1N1)pdm09 and B) and Eastern Asia (predominantly A(H1N1)pdm09). Activity increased in a few countries in Central America and Caribbean, Northern, Western and Eastern Africa and there were mixed trends of activity in Tropical South America, Europe and Asia.
• In the Southern hemisphere, elevated activity was observed in single countries in Eastern Africa (predominantly A(H3N2) and B) and South-East Asia (predominantly A(H1N1)pdm09 and B) and multiple countries in Oceania (predominantly A(H1N1)pdm09). Overall, activity remained the same or decreased.

 

SARS-CoV-2

• Globally, SARS-CoV-2 activity continued to be low across reporting countries with a few exceptions of elevated activity reported in some parts of Central America and Caribbean, Tropical and Temperate South America and Oceania. Activity increased in a few countries in Tropical and Temperate 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://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.