2023-12-26-世界卫生组织-Influenza_Update_N°_461_12页_1mb

Influenza Update Summary (December 27, 2023)

Key Recommendations

• Countries should monitor co-circulation of influenza and SARS-CoV-2 viruses through integrated surveillance using FluNet or regional platforms, reporting data to RespiMART.
• Clinicians are advised to include influenza in differential diagnoses, especially for high-risk groups, and follow national and WHO guidelines for testing and treatment.

Global Influenza Activity

• Influenza detections increased globally, primarily driven by temperate zones in the Northern Hemisphere (e.g., Europe, Central and Eastern Asia, North America).
• Influenza activity was increasing but generally below epidemic thresholds except in areas where positivity exceeded 10%, such as parts of Europe and North America.
• Influenza A(H1N1)pdm09 and A(H3N2) viruses dominated detections in most regions, with some tropical and southern hemisphere areas reporting lower activity.
• Specific highlights:
  • Northern Hemisphere Temperate Zones: Activity above seasonal baselines in North America and Europe; A(H1N1)pdm09 predominant in North America.
  • Southern Hemisphere Temperate Zones: Activity remained low across reporting countries (e.g., Australia, New Zealand).
  • Tropical Zones: Low activity reported in central America, South America, Africa, and Asia; some increases noted in East and Middle Africa.

SARS-CoV-2 and RSV Surveillance

• SARS-CoV-2 positivity from sentinel surveillance increased slightly globally (around 7%), with higher rates in Europe (up to 20%), while RSV activity showed regional increases in North America and stability in Europe.
• WHO encourages enhanced integrated surveillance, particularly for countries with access to multiplex reagent kits.
• RSV details available where reported, with activity increasing in North America but declining elsewhere.

Regional Breakdown

• Europe and Central Asia: Influenza activity low to moderate, increasing towards thresholds; SARS-CoV-2 positivity stable across regions.
• East and Western Asia: Activity increased, mainly due to China and Korea, with A(H3N2) predominant in some areas.
• North Africa: Influenza increased in Algeria, decreased in Egypt; SARS-CoV-2 low.
• Americas: Caribbean moderate activity, Central America low but increasing; SRS-CoV-2 low.
• Africa: Western Africa saw decreases in detections; Middle and Eastern Africa reported elevated activity.
• South and Southeast Asia: Influenza activity decreased or stabilized, with A(H1N1)pdm09 predominant.
• Oceania and Southern Africa: Low influenza activity; SARS-CoV-2 positivity elevated in some regions.

Data Sources and Notes

• Data from November 27 to December 10, 2023, with WHO GISRS laboratories testing over 424,940 specimens.
• Surveillance completeness varies due to data availability and quality.
• For detailed regional information, refer to WHO Regional Offices' reports or the FluNet dashboard.