Influenza Update N° 534

Overview

^{Published 09 July 2025 | For reporting Week 26, ending 29 June 2025}

Influenza

• Globally, influenza activity continued to decrease and was low with influenza A(H1N1)pdm09 viruses predominant.
• In the Southern Hemisphere, influenza activity remained stable with a small increase reported from a single country in South-East Asia. Influenza positivity was elevated in countries of Tropical and Temperate South America, Southern and Eastern Africa and South-East Asia.
• In the Northern Hemisphere, influenza remained stable in most countries with increases reported from single countries in Eastern Africa and Southern Asia. Influenza positivity remained elevated in Central America and the Caribbean, Tropical South America, Western and Eastern Africa, Western, Southern and South-East Asia.
• Influenza A(H1N1)pdm09 predominated in the Americas and Western Africa whilst influenza A(H3N2) was the predominant circulating virus in Southern Africa, Western and Southern Asia. Influenza A(H1N1)pdm09 and influenza A(H3N2) were co-dominant in Eastern Africa and South-East Asia.

 

SARS-CoV-2

• Globally, SARS-CoV-2 positivity remained stable and low across the majority of reporting countries. Positivity was elevated (>10%) and increased in a few countries in Central America and the Caribbean, Western Africa, South West Europe, Western, Southern and South-East Asia. Small increases were also reported in a single country in Northern Europe.

 

Respiratory Syncytial Virus (RSV)

• Among reporting countries, RSV positivity remained low overall, with elevated activity reported in a few countries in Central America and the Caribbean, Tropical and Temperate South America. Overall, RSV activity remained stable compared to previous weeks, except for slight increases in Central America and the Caribbean, Temperate South America and Northern Europe.

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.