Influenza Update N° 525

Overview

^{Published 07 May 2025 | For reporting Week 17, ending 27 April 2025}

Influenza

• In the Northern hemisphere, influenza positivity continued to decline or remained stable in most countries. Influenza positivity remained elevated in Central America and the Caribbean and Tropical South America (predominantly A(H1N1)pdm09), in Western Africa (predominantly A(H1N1)pdm09), Eastern Africa (predominantly A viruses), in Europe and Western Asia (predominantly A(H3N2) and B), in Southern Asia (predominantly A(H3N2)), Eastern Asia (predominantly A(H1N1)pdm09 and B) and South-East Asia (predominantly A viruses).
• In the Southern hemisphere, positivity remained stable with small increases in Temperate South America. Influenza positivity was elevated in a few countries in Tropical and Temperate South America and Oceania (predominantly A(H1N1)pdm09), Southern Africa (predominantly A(H3N2)), Eastern Africa and South-East Asia (predominantly Influenza A Viruses) and Oceania (predominantly A(H1N1)pdm09).

 

SARS-CoV-2

• Globally, positivity continued to remain low across reporting countries except for single countries in Central America and the Caribbean, South-West Europe and Western Asia.

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.