^{Published 5 November 2025 | For reporting Week 43, ending 26 October 2025}

Influenza

• Globally, influenza activity remained low, with influenza A viruses continuing to predominate.
• In the northern hemisphere, influenza activity remained low and stable in most countries. Influenza percent positivity was elevated in a few countries in Central America and the Caribbean, Northern Europe, and Eastern Asia, and was over 30% in Western, Eastern and Middle Africa, Western, Southern and South-East Asia. Small increases in activity were observed in countries in Central America and the Caribbean, Western, Eastern and Middle Africa, South West and Northern Europe, Western, Southern and South-East Asia.
• In the southern hemisphere, influenza activity remained low and stable in most countries with elevated positivity (>10%) in single countries in Temperate South America and Eastern Africa and percent positivity over 30% in a single country in South-East Asia. A small increase in activity was observed in a single country in Temperate South America.
• In the transmission zones with elevated positivity, influenza A(H1N1)pdm09 predominated in Central America and the Caribbean, Eastern and Middle Africa whereas influenza A(H3N2) was predominant in Temperate South America, Northern Europe, Western, Southern and South-East Asia. Influenza A(H1N1)pdm09 and influenza A(H3N2) were codominant in Western Africa.

SARS-CoV-2

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

Respiratory Syncytial Virus (RSV)

• RSV percent positivity remained elevated in single countries in Western and Eastern Africa and Eastern Asia, and over 30% in two countries in Central America and the Caribbean. RSV positivity remained stable across most countries, with increases in activity in a few countries in Central America and the Caribbean and one country in South West Europe. RSV and influenza activity were both elevated in a few countries of Central America and the Caribbean and one country in Western Africa. 

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.