Based on data reported to WHO for week 48, ending 30 November 2025

SUMMARY

Globally, influenza activity was elevated with positivity above 15% in week 48. SARS-CoV-2 activity remained stable and low overall. Influenza predominated in all areas with positivity above 10% in the northern hemisphere temperate and sub-tropical zones and in the tropical zones.

Influenza

Globally, influenza activity continued to increase with influenza A viruses predominant among influenza detections in all zones.

In the northern hemisphere, influenza percent positivity was elevated (>10%) in countries in Central America and the Caribbean, Tropical South America, Africa, Northern and South-West Europe, and Southern, South-East and Western Asia. Percent positivity was over 30% in countries in Central America and the Caribbean, Tropical South America, Western Africa, Northern and South West Europe and Eastern, Southern, South-East and Western Asia. Increases in activity were observed in countries in North America, Central America and the Caribbean, Western Africa, Eastern, Northern and South West Europe, and Asia.

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

In the zones with elevated positivity, influenza A(H3N2) was predominant in all zones except Central America and the Caribbean and Northern Africa where there was codominance of influenza A(H1N1)pdm09 and A(H3N2).

SARS-CoV-2

Globally, SARS-CoV-2 positivity remained stable and low, with some countries reporting elevated positivity (>10%) in Central America and the Caribbean, Temperate South America and Europe. Percent positivity was over 30% in a single country in South West Europe. Small increases in activity were reported in single countries in Temperate South America, Northern Europe and Southern Asia.

Respiratory Syncytial Virus (RSV)

RSV activity was stable and low overall although elevated percent positivity (>10%) was reported in few countries in Central America and the Caribbean and South West Europe. Increases in activity compared to the previous reporting period were reported in few countries in Central America and the Caribbean, South West Europe and Western Asia. [Figures 9 and 10] RSV and influenza activity were both elevated in one country in South West Europe.

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.