Global Respiratory Virus Activity: Weekly Update N° 565

Overview

Globally, influenza activity remained stable and positivity was just above 15% in week 6 2026. SARS-CoV-2 activity remained low overall. Influenza predominated and positivity was around 15% in the northern hemisphere temperate and subtropical areas and the tropical areas. In the southern hemisphere temperate and subtropical areas, influenza and SARS-CoV-2 positivity were both low.

Influenza

Globally, influenza detections continued to decline in week 6. Influenza A viruses were predominant among influenza detections, with a slight increase in the proportion of influenza B virus detections in recent weeks.

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

In the southern hemisphere, influenza activity remained low overall although elevated positivity (>10%) was reported in single countries in Temperate South America and Eastern Africa and two countries in Tropical South America. Percent positivity was over 30% in a single country in Oceania. No increases in activity were observed in any countries in the southern hemisphere.

In the zones with elevated positivity, influenza A(H3N2) was predominant in most of the zones except Western Africa where influenza B was predominant.

SARS-CoV-2

Globally, SARS-CoV-2 positivity remained stable and low, with single countries reporting elevated positivity (>10%) in Temperate South America, South West and Northern Europe. Small increases in activity were reported in single countries in South West and Northern Europe.

Respiratory Syncytial Virus (RSV)

Globally, RSV positivity remained stable and low, with a few countries reporting elevated positivity (>10%) in Central America and the Caribbean, Northern Africa, South West and Northern Europe and Western Asia. Small increases in activity were reported in a few countries in Central America and the Caribbean and Northern Europe and in single countries in Northern Africa, South West and Eastern Europe and Western Asia. RSV and influenza activity were both elevated in countries in Central America and the Caribbean, Northern Africa, South West and Northern Europe and Western Asia.

Severity assessment

The severity assessments here are reported from countries, areas and territories. Assessments for transmissibility can be reported based on syndromic parameters and/or influenza-specific parameters. In the northern hemisphere temperate and subtropical areas, influenza-specific transmissibility was reported as low (1) and moderate (1); transmissibility using syndromic data was reported as below seasonal threshold (12), low (8), moderate (12) and high (1). Influenza-specific transmissibility was reported as below seasonal threshold in a single country in the southern hemisphere temperate and subtropical areas. 

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.

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.