2023-02-19-世界卫生组织-Influenza_Update_N°_439_11页_910kb

Influenza Update Summary for 20 February 2023

This update provides global influenza surveillance data up to 5 February 2023, integrating influenza and SARS-CoV-2 monitoring through WHO's Global Influenza Surveillance and Response System (GISRS) and FluNet.

Key recommendations include enhancing surveillance of co-circulation of influenza and SARS-CoV-2 viruses, increasing influenza vaccination campaigns in northern hemisphere countries, and encouraging clinicians to consider influenza in differential diagnoses for high-risk groups, with caution due to pandemic-related changes in surveillance.

Globally, influenza activity decreased from late 2022 peaks. Influenza A viruses were predominant, with A(H1N1)pdm09 making up a larger proportion in some regions, while influenza B virus detections increased.

Regional influenza activity:

• North America: Activity low; A viruses predominant, with specific subtypes dominating in USA and Canada.
• Europe: Detections stable; A viruses predominant, with regional variations in subtypes and B virus increases noted.
• Central Asia: Decreased activity but elevated positivity.
• Northern Africa: High activity in Morocco and Tunisia, with all subtypes detected.
• Western and East Asia: Low activity, but some elevations reported.
• Caribbean and South America: Influenza activity decreasing, with RSV also low.
• Tropical Africa and Southern Asia: No major increases, with all subtypes circulating where data available.

SARS-CoV-2 surveillance showed stable global positivity rates of around 20% from sentinel sources, with enhanced guidance to integrate influenza and SARS-CoV-2 surveillance.

Additional information: Data from FluNet and GISRS laboratories, with full details available on WHO regional influenza websites. Contact for inquiries: fluupdate@who.int.