2024-02-04-世界卫生组织-Influenza_Update_N°_464_12页_1mb

Influenza Update Summary

Recommendations

Countries should monitor integrated influenza and SARS-CoV-2 surveillance via FluNet or regional platforms. Clinicians should consider influenza in differential diagnoses for high-risk groups and follow national/WHO guidance.

Global Trends

• Elevated influenza activity mostly persisted in Northern Hemisphere temperate zones.
• Global influenza detections decreased.
• SARS-CoV-2 sentinel surveillance peaked around 10% positivity in GISRS regions.

Regional Activity - Northern Temperate Zones

• North America: Influenza activity decreasing gradually; A(H1N1)pdm09 predominated. Hospitalizations stabilized. RSV declining.
• Europe & Central Asia: High activity persists overall; A(H1N1)pdm09 and A(H3N2) predominant, but detection rates may have dropped. SARI and ICU admissions lower; SARS-CoV-2 positivity in care settings low/elevated in some countries.
• Northern Africa: High influenza activity, mainly A(H1N1)pdm09 and A(H3N2); Morocco increases integrated SARS-CoV-2.
• Eastern Asia: Activity decreasing; Japan reports mixed activity; Korean Peninsula activity stable.
• Western Asia:Activity decreasing; Armenia, Georgia, and Israel report elevated A virus activity.
• Central & Caribbean Americas: Influenza activity decreased; predominated by A(H1N1)pdm09 in Caribbean, A(H3N2) in Central America; ILI increased in Central America.

Other Regions

• Southern Hemisphere Temperate Zones: Influenza activity remained low through winter months.
• Tropical Regions: Influenza activity generally low in tropical zones; SARS-CoV-2 activity variable.

RSV

Surveillance indicates generally decreasing or low activity globally, except for elevated influenza detections in some countries.

SARS-CoV-2 Trends

SARS-CoV-2 positivity varied by region: highest in Europe and the Americas. Non-sentinel positivity decreased slightly.

Lineages

Nearly all type B influenza viruses detected belonged to the B/Victoria lineage.

Data

Global positive influenza detections noted by subtype and region during the period are provided via FluNet charts. 118 countries reported to FluNet.