2023-06-25-世界卫生组织-Influenza_Update_N°_448_11页_1mb

Influenza Update N° 448 Summary (26 June 2023)

Core Content

This update provides an overview of global influenza and SARS-CoV-2 surveillance data as of 11 June 2023, with additional information on respiratory syncytial virus (RSV) where available. The data are collected through the WHO Global Influenza Surveillance and Response System (GISRS) and reported to FluNet via regional platforms.

Main Points

• Integrated Surveillance: Countries are advised to monitor the co-circulation of influenza and SARS-CoV-2 and report data to FluNet or regional platforms. Enhanced integrated surveillance is encouraged, especially in southern hemisphere countries to prepare for influenza vaccination campaigns.
• Influenza Activity by Region:
  • Global: Influenza detections remained low overall, but there were variable changes in southern hemisphere countries.
  • Oceania: Influenza activity continued to increase, with A viruses predominant.
  • South Africa: Influenza activity decreased, remaining moderate in pneumonia and low in ILI.
  • Temperate South America: Influenza activity decreased, mainly in Chile, with A(H1N1)pdm09 and B viruses detected. Argentina and Paraguay reported increased activity, with RSV elevated in Chile, Paraguay, and Uruguay.
  • Caribbean: Influenza activity remained low, with B/Victoria lineage viruses predominant.
  • Central America: Increased influenza activity was reported in several countries, with A(H1N1)pdm09 and B/Victoria viruses detected. RSV activity was low except in Guatemala.
  • Tropical South America: Influenza activity decreased overall, with A(H1N1)pdm09 and B viruses predominant. RSV activity continued in Bolivia and Colombia.
  • Tropical Africa: Low influenza detections across all subregions, with A(H1N1)pdm09 predominant.
  • Southern Asia: Influenza activity remained low with all seasonal subtypes detected. SARS-CoV-2 activity decreased or remained low.
  • South-East Asia: Influenza activity was stable, with A(H1N1)pdm09 predominant in several countries. RSV activity was low.
  • Northern Hemisphere (Temperate): Influenza activity was low or below seasonal thresholds. Influenza B viruses were predominant in Europe and North America. SARS-CoV-2 activity was low in most regions, with some increases in Caribbean countries.
• RSV Activity: Generally low globally, except in Australia and some countries in the Americas. RSV activity increased in parts of South America and was reported in the Caribbean and Central America.
• Testing Data:
  • Sentinel Surveillance: 6709 influenza-positive specimens were reported globally, with 4221 (62.9%) as A and 2488 (37.1%) as B. A(H1N1)pdm09 (73.6%) and A(H3N2) (26.4%) were the main subtypes. All B viruses belonged to the B/Victoria lineage.
  • SARS-CoV-2: 6291 (17.2%) of sentinel specimens were positive for SARS-CoV-2, with positivity rates decreasing in most regions.

Key Information

• Reporting Period: 29 May to 11 June 2023.
• Data Sources: FluNet, FluID, and reports from WHO Regional Offices.
• Global Influenza Centres: 108 countries reported influenza data; 73 reported SARS-CoV-2 data.
• WHO Recommendations: Clinicians should consider influenza in differential diagnoses, particularly for high-risk groups. Countries are encouraged to enhance integrated surveillance and share data promptly.
• RSV and SARS-CoV-2 Trends: While influenza activity was low in many regions, RSV and SARS-CoV-2 showed variable trends, with some increases noted in specific areas.

Data Visualizations

• Influenza Subtype Distribution: Maps and charts are provided showing the distribution of influenza subtypes by region.
• Sentinel Surveillance Data: Graphs illustrate the positivity rates of influenza and SARS-CoV-2 in various WHO regions.

Additional Resources

• Influenza Reports: Available on WHO Regional Office websites.
• Integrated Surveillance Dashboard: Provides detailed data on influenza and other respiratory viruses.
• Contact: fluupdate@who.int for further inquiries.

Conclusion

This update highlights the ongoing low levels of influenza activity globally, with some regional variations. Integrated surveillance of influenza and SARS-CoV-2 is emphasized, and countries are urged to continue monitoring and reporting. RSV activity remains generally low, but there are exceptions in certain regions.