2022-12-11-世界卫生组织-Influenza_Update_N°_434_12页_978kb

Influenza Update Summary (December 12, 2022)

Key Points

• Co-circulation: Countries are advised to monitor and enhance influenza surveillance alongside SARS-CoV-2 and conduct integrated surveillance. Increased vaccination campaigns, differential diagnosis by clinicians, and timely reporting are encouraged.
• Increased Surveillance Thresholds: Inflow positivity was notably high and frequently above seasonal thresholds across multiple regions.

Global Summary

• Predominant Strain: Influenza A(H3N2) was the predominant virus detected globally, followed by influenza B/Victoria lineages and influenza A(H1N1)pdm09.

Regional Summaries

North America

• Trend: High influenza positivity and ILI activity rates with many indicators exceeding historical levels; A(H3N2) dominated; hospitalizations high in children and seniors; co-circulation with other respiratory viruses.

Europe

• Activity: Influenza activity generally increasing; above epidemic threshold for surveillance in many regions. A(H3N2) predominant.

Central Asia & Northern Africa

• Moderate or low influenza activity, with limited A(H3N2) and B/Victoria detections.

Western Asia

• Recorded a decrease in influenza activity compared to previous periods.

East Asia & South-East Asia

• Influenza activity generally low, though increases in southern China and Republic of Korea noted.

Caribbean & South America (Tropical)

• Fluctuating activity; A(H3N2) predominant in several countries including Brazil, Bolivia, Colombia; RSV activity reported.

Tropical & Temperate Southern Hemisphere

• Except in Argentina and Chile where activity remained elevated, influenza activity generally low.

SARS-CoV-2 Co-circulation

• Ongoing circulation in all WHO regions, though with variability.
• Integration noted between SARS-CoV-2 and influenza surveillance systems globally.

Data Interpretation Note

Due to COVID-19 pandemic changes in respiratory virus surveillance, direct comparisons with previous years' data are generally not valid and should be interpreted with caution.

Contact

For further details, contact: fluupdate@who.int