2025-01-14-世界卫生组织-Influenza_Update_N°_509_1页_1mb

Global Respiratory Virus Activity Summary

Influenza

• Northern Hemisphere: Influenza activity was elevated in many countries, including:
  • Europe: Primarily A(H1N1)pdm09, with A(H3N2) more common in Eastern Europe.
  • North America: Co-circulation of A(H1N1)pdm09 and A(H3N2).
  • Central America and Caribbean: Mainly A(H3N2).
  • Western Africa: Mostly A(H1N1)pdm09 and B viruses.
  • Middle Africa: Primarily A(H1N1)pdm09.
  • Northern Africa: Mostly A(H3N2).
  • Asia: Widespread A(H1N1)pdm09 in many countries.
• Southern Hemisphere: Elevated activity in a few countries, such as Tropical South America (A(H3N2) and B viruses co-circulating), Eastern Africa (mostly B viruses), and Melanesia (mostly A(H1N1)pdm09). Activity was similar or declining in other regions.

SARS-CoV-2 Activity

• Elevated activity reported in parts of South America, Eastern Africa, Southern Asia, and Southeast Asia. Increased cases in Central America and parts of Southern Asia, while activity was stable or declining elsewhere.

Additional Information

• Data from the Global Influenza Surveillance and Response System (GISRS) provide surveillance through various methods, with virologic results smoothed over a 3-week period for positivity rates. Changes are based on smoothed proportion differences from prior weeks. Respiratory virus transmission varies by region, and detailed analyses are available via RespiMart.

Notes on Data Collection

• Respiratory virus surveillance data are submitted to WHO via GISRS, with methods varying by country/area/territory. This limits direct comparisons, and COVID-19 updates are found on the WHO COVID-19 dashboard.