^{Published 19 November 2025 | For reporting Week 45, ending 09 November 2025}

Influenza

Globally, influenza activity continued to increase with influenza A viruses predominantly detected in all zones.

In the northern hemisphere, influenza activity remained low in most countries although increasing activity was reported in some countries. Influenza percent positivity was elevated in a few countries in Central America and the Caribbean, Northern and Western Africa, Northern Europe and Eastern Asia, and was over 30% in a few countries in Western, Eastern and Middle Africa, Western, Southern and South-East Asia. Increases in activity were observed in countries in Central America and the Caribbean, Northern and Eastern Africa, South West and Northern Europe, Western, Southern, South-East and Eastern Asia.

In the southern hemisphere, influenza activity remained low and stable in most countries with elevated positivity (>10%) in a single country in Temperate South America; percent positivity was over 30% in single countries in Eastern Africa and South-East Asia. Small increases in activity were observed in Tropical South America and Eastern Africa.

In the zones with elevated positivity, influenza A(H1N1)pdm09 predominated in Central America and the Caribbean, Northern and Middle Africa whereas influenza A(H3N2) was predominant in all other zones.

SARS-CoV-2

Globally, SARS-CoV-2 positivity remained stable at low levels, with some countries reporting elevated positivity (>10%) in Tropical and Temperate South America, South West and Eastern Europe, and Western Asia. Percent positivity was over 30% in one country in South West Europe and Western Asia. Increases in activity were reported in single countries in Central America and the Caribbean, Temperate South America and Western Asia and two countries in South-West Europe.

Respiratory Syncytial Virus (RSV)

RSV percent positivity remained elevated in Central America and the Caribbean and Eastern Africa. Compared to the previous reporting period, RSV positivity remained stable across most countries, with increases in activity in two countries in Central America and the Caribbean and one country in Tropical South America. RSV and influenza activity were both elevated in one country Central America and the Caribbean.

 

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.