2024-03-14-世界卫生组织-COVID-19_epidemiological_update_–_15_March_2024_28页_2mb

Summary of the COVID-19 Epidemiological Update (Edition 165, 15 March 2024)

Core Content

This report provides an epidemiological overview of the global and regional status of SARS-CoV-2 as of 3 March 2024, highlighting trends in case numbers, hospitalizations, ICU admissions, and SARS-CoV-2 variants. It also emphasizes the challenges in data collection and interpretation due to reduced testing, sequencing, and reporting.

Key Highlights

• PCR Positivity Rate: The global average SARS-CoV-2 PCR percent positivity was approximately 11.4% during the week ending 3 March 2024.
• Variants: JN.1 is the most reported variant of interest (VOI), now tracked in 115 countries, accounting for 90.3% of sequences in week 9 compared to 89.4% in week 6. Its parent lineage, BA.2.86, has declined from 3.0% to 2.2%. Other VOIs include XBB.1.5, XBB.1.16, EG.5, and BA.2.86. VUMs include XBB, XBB.1.9.1, and XBB.2.3.
• Case and Death Trends:
  • During the 28-day period (5 February to 3 March 2024), the number of reported cases decreased by 44%, and deaths decreased by 51% compared to the previous 28 days (8 January to 4 February 2024).
  • Over 292,000 new cases and 6,200 new deaths were reported.
  • Clinical detection of cases underestimates the real burden by 2 to 19-fold, according to wastewater surveillance.
• Reporting Limitations:
  • Only 32% of countries reported at least one case to WHO during the 28-day period.
  • 46 countries reported deaths, but many have stopped or changed reporting frequency.
  • Hospitalization and ICU admission data are also incomplete and subject to reporting delays.
• WHO Dashboard Update:
  • The WHO global COVID-19 dashboard was updated on 22 December 2023 to support transition from emergency to disease management.
  • The new dashboard will include more components throughout 2024.

Global Overview

• Total Cases and Deaths:
  • Over 774 million confirmed cases and over 7 million deaths have been reported globally as of 3 March 2024.
• Regional Trends:
  • All WHO regions reported a decrease in new cases and deaths over the 28-day period.
  • Africa saw the largest decline in new cases (-87%) and deaths (-33%).
  • Europe had the largest decline in deaths (-69%).
• Country-Level Data:
  • Highest new cases: Russian Federation (+5%), Australia (-24%), Chile (+72%), New Zealand (-16%), Argentina (-45%).
  • Highest new deaths: United States (-45%), Russian Federation (-53%), Australia (-37%), Italy (-77%), Chile (+24%).

Hospitalizations and ICU Admissions

• Global Hospitalizations and ICU Admissions:
  • 78,038 new hospitalizations and 500 new ICU admissions were reported from 44 and 31 countries, respectively.
  • The overall decrease in hospitalizations was 34%, and in ICU admissions was 61% compared to the previous 28-day period.
• Regional Reporting:
  • Americas had the highest proportion of countries reporting hospitalizations (39%) and ICU admissions (20%).
  • Europe had the highest number of consistent reporters for ICU admissions (11%).
• Countries with Increases:
  • Guatemala, Chile, Namibia, and Bangladesh reported increases in hospitalizations.
  • Chile reported a +121% increase in ICU admissions.
• Notes:
  • Reporting delays and incomplete data affect interpretation.
  • WHO encourages countries to report "zero reporting" when no new admissions occur.

Severity Indicators

• ICU-to-Hospitalization Ratio:
  • Has decreased since July 2021, from 0.26 to around 0.05 in 2023, but showed a marginal increase in recent weeks.
• Death-to-Hospitalization Ratio:
  • Has declined since July 2021 and remained below 0.15 since January 2023, ranging from 0.06 to 0.14.
• Interpretation:
  • These ratios are not definitive indicators of virus virulence but may reflect improved care, immunity, and health system capacity.
  • The decline does not necessarily indicate reduced disease severity.

SARS-CoV-2 Variants of Interest and Variants Under Monitoring

• Global Sequence Sharing:
  • 14,764 sequences were shared through GISAID during the 28-day period (5 February to 3 March 2024).
  • This is a decrease from 52,965 and 85,807 in the two prior 28-day periods.
• Variant Trends:
  • JN.1 is the most prevalent VOI, showing a slight decrease in prevalence from 91.4% to 90.3%.
  • XBB.1.5, XBB.1.16, and EG.5 showed stable or decreasing prevalence.
  • BA.2.86 (parent of JN.1) has been declining.
  • All VUMs showed decreasing trends.
• Data Limitations:
  • Reduced global testing and sequencing make it difficult to assess the severity impact of emerging variants.
  • No evidence suggests that any VOI/VUM is associated with increased disease severity.

Conclusion

• The global epidemiological situation for SARS-CoV-2 appears to be in decline, with reduced case and death numbers.
• JN.1 remains the dominant variant, but its public health risk is considered low globally.
• Hospitalization and ICU admission data show a general decrease, though some countries report increases.
• WHO continues to monitor variants and urges Member States to maintain surveillance and reporting infrastructure to support long-term disease management.