Global Respiratory Virus Activity: Weekly Update N° 591

Overview

In week 32 2026, influenza positivity was below 10% and SARS-CoV-2 activity remained low globally. During the past few weeks, influenza positivity increased but remained below 10% overall in the northern hemisphere temperate and subtropical areas. RSV positivity also remained low globally.

Influenza

Globally, influenza detections remained low in week 32 with influenza A and B viruses detected in similar proportions.

In the southern hemisphere, influenza percent positivity was elevated (>10%) in some countries in Temperate South America and in single countries in Southern Africa and Oceania. A small increase in activity was observed in a single country in Oceania.

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

In the zones with elevated positivity, influenza A(H3N2) was predominant in Central America and the Caribbean, Eastern and Middle Africa, Eastern Asia and Oceania; influenza A(H1N1)pdm09 was predominant in Western, Southern and South-East Asia and influenza B was predominant in Tropical and Temperate South America. Influenza A and B were codominant in Western and Southern Africa.

SARS-CoV-2

Globally, SARS-CoV-2 positivity remained stable and low across most reporting countries, with elevated positivity (>10%) reported in countries in Central America and the Caribbean and in single countries in Tropical South America, Western Africa, Northern Europe and South-East Asia. Small increases in activity were observed in countries in Central America and the Caribbean, Southern Asia and in a single country in Western Africa.

Respiratory Syncytial Virus (RSV)

RSV positivity was elevated (>10%) in a few countries in Central America and the Caribbean, Tropical and Temperate South America and in single countries in Western and Eastern Africa and Southern Asia. Percent positivity was over 30% in single countries in Central America and the Caribbean and Temperate South America. Small increases in activity were observed in single countries in Central America and the Caribbean and Temperate South America. RSV and influenza activity were both elevated in a few countries in Central America and the Caribbean, Temperate South America and in single countries in Western Africa and Southern 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 southern hemisphere temperate and subtropical areas, influenza-specific transmissibility was reported as extraordinary (1); transmissibility using syndromic data was reported as moderate (1). In the northern hemisphere temperate and subtropical areas, influenza-specific transmissibility was reported as below seasonal threshold (12); transmissibility using syndromic data was reported as below seasonal threshold (7). Influenza-specific transmissibility was reported as below seasonal threshold in one country in the tropical 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.