Influenza update - 376

14 September 2020 - Update number 376, based on data up to 01 September 2020

Information in this report is categorized by influenza transmission zones, which are geographical groups of countries, areas or territories with similar influenza transmission patterns. For more information on influenza transmission zones, see the link below:

Summary

The current influenza surveillance data should be interpreted with caution as the ongoing COVID-19 pandemic have influenced to varying extents health seeking behaviours, staffing/routines in sentinel sites, as well as testing priorities and capacities in Member States. The various hygiene and physical distancing measures implemented by Member States to reduce SARS-CoV-2 virus transmission have likely played a role in reducing influenza virus transmission.



Globally, influenza activity was reported at lower levels than expected for this time of the year. In the temperate zones of the southern hemisphere, the influenza season has not started. Despite continued or even increased testing for influenza in some countries in the southern hemisphere, very few influenza detections were reported.

In the temperate zone of the northern hemisphere, influenza activity remained below inter-seasonal levels.

In the Caribbean and Central American countries, no influenza detections were reported. Severe acute respiratory infection (SARI) activity, likely due to COVID-19, appeared to decrease in some reporting countries.

In tropical South America, tropical Africa and Southern Asia there were sporadic or no influenza detections across reporting countries.

In South East Asia, influenza A(H3N2) virus detections were reported in Cambodia.

Worldwide, of the very low numbers of detections reported, seasonal influenza A viruses accounted for the majority of detections.



National Influenza Centres (NICs) and other national influenza laboratories from 52 countries, areas or territories reported data to FluNet for the time period from 17 August 2020 to 30 August 2020 (data as of 2020-09-11 02:38:29 UTC). The WHO GISRS laboratories tested more than 1450681 specimens during that time period: 34 were positive for influenza viruses, of which 19 (55.9%) were typed as influenza A and 15 (44.1%) as influenza B. Of the sub-typed influenza A viruses, 0 (0%) were influenza A(H1N1)pdm09 and 11 (100%) were influenza A(H3N2). Of the characterized B viruses, 3 (37.5%) belonged to the B-Yamagata lineage and 5 (62.5%) to the B-Victoria lineage.

WHO encourages the testing of routine influenza surveillance samples from sentinel and non-sentinel sources for influenza and SARS-CoV-2 virus where resources are available and report this information, separate data from sentinel and non-sentinel sites if possible, to established regional and global platforms (See the Operational considerations for COVID-19 surveillance using GISRS guidance)

Detailed influenza update

Influenza fact sheet

Seasonal update

Source of data

The Global Influenza Programme monitors influenza activity worldwide and publishes an update every two weeks. The updates are based on available epidemiological and virological data sources, including FluNet (reported by the WHO Global Influenza Surveillance and Response System), FluID (epidemiological data reported by national focal points) and influenza reports from WHO Regional Offices and Member States. Completeness can vary among updates due to availability and quality of data available at the time when the update is developed.

1It includes data only from countries reporting on positive and negative influenza specimens.