2023-07-09-世界卫生组织-Influenza_Update_N°_449_10页_1mb

Overview

This WHO Influenza Update (Number 449) from 10 July 2023, based on data up to 25 June 2023, provides a global surveillance summary of influenza, SARS-CoV-2, and respiratory syncytial virus (RSV). It includes recommendations for integrated monitoring and highlights trends across regions.

Influenza Surveillance

• Global Activity: Influenza detections remained low overall, with regional variations. The southern hemisphere showed some increases, while northern temperate zones reported low activity.
• Regional Highlights:
  • Oceania: Influenza activity stable or increasing with A viruses predominant; Australia reported rising detections.
  • Southern Africa: Activity peaked and decreased, with A(H3N2) predominant.
  • Temperate South America: Activity decreased, with moderate decreases in ILI cases; SARI elevated in some countries.
  • Caribbean and Central/South America: Generally low activity, with B/Victoria and A(H1N1)pdm09 predominant; Costa Rica, Honduras, and Nicaragua reported increases.
  • Tropical Asia and Africa: Low detections; South-East Asia reported stable or decreasing activity.
  • Northern Hemisphere: Mostly low levels, below seasonal thresholds, with A(H1N1)pdm09 and B viruses common.
• Subtype Distribution: Globally, influenza A was predominant, with A(H1N1)pdm09 and A(H3N2) being the main subtypes; B/Victoria lineage dominated B detections.

SARS-CoV-2 Surveillance

• Global Activity: SARS-CoV-2 positivity decreased to about 13% from sentinel surveillance; non-sentinel surveillance showed around 16% positivity.
• Regional Trends: Activity dropped in most regions, with decreases in the Western Pacific and Americas, and below 10% in other areas.

RSV Surveillance

• Activity: Generally low globally except in Australia and parts of South America; trends varied by region.

Key Recommendations

• Countries should monitor co-circulation of influenza and SARS-CoV-2 via integrated surveillance and report data to RespiMART or regional platforms.
• Clinicians should include influenza in differential diagnoses for high-risk groups and follow national/WHO guidelines for testing and treatment.
• WHO encourages timely reporting to established global and regional platforms for better data integration.

Data and Reporting

• Data from 107 countries via FluNet and GISRS; WHO GISRS laboratories tested over 265,159 specimens, with 6,147 influenza positives.
• Report includes SARS-CoV-2 sentinel and non-sentinel surveillance, with limited global coverage.