Global Respiratory Virus Activity: Weekly Update N° 588

Overview

In week 29 2026, influenza positivity remained below 10% and SARS-CoV-2 activity remained low globally. Influenza positivity was around 15% in the southern hemisphere temperate and subtropical areas. RSV positivity also remained low globally.

Influenza

Globally, influenza detections remained low in week 29 with influenza A and B viruses detected in similar proportions.

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

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

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

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 Tropical South America and in single countries in Middle Africa and South-East Asia. Small increases in activity were observed in some countries in Central America and the Caribbean and in single countries in Tropical South America, Southern and South-East Asia.

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 a single country in Southern Africa. 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 and Temperate South America and in single countries in Tropical South America and Southern Africa.

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 below seasonal threshold (1); transmissibility using syndromic data was reported as below seasonal threshold (1). In the northern hemisphere temperate and subtropical areas, influenza-specific transmissibility was reported as below seasonal threshold (11) and low (1); 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.