2023-06-07-世界卫生组织-Weekly_epidemiological_update_on_COVID-19_-_8_June_2023_17页_1mb

报告摘要

Summary of the WHO COVID-19 Weekly Epidemiological Update (Edition 146, 8 June 2023)

Core Content

This report provides an overview of the global and regional trends in SARS-CoV-2 infections, hospitalizations, deaths, and the emergence of new variants as of 4 June 2023.

Global Overview

New Cases and Deaths:
- Over 1.7 million new cases and over 10,000 deaths were reported in the last 28 days (8 May to 4 June 2023), representing a 38% decrease in cases and 47% decrease in deaths compared to the previous 28-day period (10 April to 7 May 2023).
- 144 out of 243 countries (59%) reported at least one case during this period.
- Cumulative cases and deaths globally reached 767 million and 6.9 million, respectively.
Data Limitations:
- Reported cases and deaths are underestimates due to reduced testing and reporting delays.
- Data is continuously updated with retrospective changes.
Regional Trends:
- All six WHO regions saw a decline in both cases and deaths.
- Western Pacific Region: -5% in cases, -19% in deaths.
- Europe: -49% in cases, -54% in deaths.
- Americas: -55% in cases, -44% in deaths.
- South-East Asia: -77% in cases, -35% in deaths.
- Eastern Mediterranean: -60% in cases, -78% in deaths.
- Africa: -22% in cases, -17% in deaths.
Country-Level Highlights:
- Highest new cases: Republic of Korea (+29%), Australia (+27%), Brazil (-33%), France (-46%), USA (-75%).
- Highest new deaths: USA (-58%), Brazil (-16%), France (-41%), Italy (-17%), Russian Federation (-44%).

Hospitalizations and ICU Admissions

Global Data:
- 79,266 new hospitalizations and 1,937 new ICU admissions were reported in the past 28 days (1 May to 28 May 2023), representing a 35% and 42% decrease from the prior 28-day period.
- Data is preliminary and subject to reporting delays.
Country-Level Trends:
- 17 countries consistently reported hospitalization data.
  - 5 countries (29%) saw a 20% or greater increase in hospitalizations: Mongolia (+1582%), Zimbabwe (+133%), Afghanistan (+99%), Bangladesh (+68%), and Indonesia (+24%).
  - Highest hospitalizations: USA (-29%), Ukraine (-41%), Indonesia (+24%).
- 9 countries consistently reported ICU admission data.
  - Only Indonesia saw a 20% or greater increase in ICU admissions (+26%).
  - Highest ICU admissions: Indonesia (+26%), Ukraine (-37%), Italy (-63%).

SARS-CoV-2 Variants of Interest and Under Monitoring

Tracking Variants:
- WHO is monitoring two variants of interest (VOIs): XBB.1.5 and XBB.1.16, along with seven variants under monitoring (VUMs): BA.2.75, CH.1.1, BQ.1, XBB, XBB.1.9.1, XBB.1.9.2, and XBB.2.3.
Geographic Spread:
- XBB.1.5 remains dominant globally, but its prevalence has declined from 46.2% in week 16 to 30.3% in week 20.
- XBB.1.16 has been rising in prevalence, reaching 16.8% in week 20.
- VUMs with increasing trends: XBB.1.9.1, XBB.1.9.2, XBB.2.3.
- VUMs with decreasing trends: BA.2.75, CH.1.1, BQ.1, XBB.
Regional Dominance:
- XBB.1.5 dominated in the African Region, Americas, and Europe.
- XBB.1.16 dominated in the South-East Asia Region.
- XBB.1.9.1 dominated in the Eastern Mediterranean Region.
- Western Pacific Region: XBB.1.9.1 (22.7%) followed by XBB.1.5 (16.2%).
Genomic Surveillance Challenges:
- Testing and sequencing levels are low and unrepresentative, making it difficult to fully assess the variant landscape.

Vaccine Effectiveness

Omicron and Descendant Lineages:
- Vaccine effectiveness (VE) against Omicron BA.4/BA.5 is likely lower than against BA.1, possibly due to reduced vaccine efficacy and methodological differences in VE studies.
- Bivalent vaccines showed a 10% higher VE against Omicron symptomatic infection compared to monovalent boosters.
- No studies have evaluated VE against severe disease for both monovalent and bivalent vaccines during the same period.
Neutralizing Antibodies:
- Neutralization studies provide early insights into vaccine performance against new variants.
- Bivalent vaccines show improved neutralization against recent Omicron descendant lineages like BQ.1 and XBB.

WHO Regional Overviews

African Region

New Cases: 6,000, a 22% decrease from the previous 28 days.
New Deaths: 15, a 17% decrease.
Countries with >20% increase in cases: Botswana (+262%), Kenya (+190%), Zimbabwe (+103%).
Countries with >20% increase in deaths: Zimbabwe (+75%), DRC (+100%).

Region of the Americas

New Cases: 294,000, a 55% decrease.
New Deaths: 4,222, a 44% decrease.
Countries with >20% increase in cases: US Virgin Islands (+272%), Saint Kitts and Nevis (+200%), Guyana (+82%).
Countries with >20% increase in deaths: Peru (+45%).

Eastern Mediterranean Region

New Cases: 15,000, a 60% decrease.
New Deaths: 153, a 78% decrease.
No country reported >20% increase in cases.
Countries with >20% increase in deaths: Afghanistan (+62%).

European Region

New Cases: 421,000, a 49% decrease.
New Deaths: 4,008, a 54% decrease.
No country reported >20% increase in cases.
Countries with >20% increase in deaths: None.

South-East Asia Region

New Cases: 59,000, a 77% decrease.
New Deaths: 760, a 35% decrease.
Countries with >20% increase in cases: Bangladesh (+400%), Timor-Leste (+138%), Thailand (+119%).
Countries with >20% increase in deaths: Thailand (+626%).

Western Pacific Region

New Cases: 924,000, a 5% decrease.
New Deaths: 1,305, a 19% decrease.
Countries with >20% increase in cases: Mongolia (+1592%), Cambodia (+644%), Lao PDR (+269%).
Countries with >20% increase in deaths: China (+130%), Republic of Korea (+37%).

Key Information

Data Sources: WHO and GISAID.
Data Limitations:
- Underestimation of actual case and death numbers.
- Reporting delays and inconsistencies across countries.
- Some countries report combined probable and confirmed cases.
Additional Resources:
- WHO COVID-19 Dashboard
- WHO Monthly Operational Update
- VIEW-hub.org for vaccine effectiveness and neutralization data.
Variant Trends:
- XBB.1.5 and XBB.1.16 are the main VOIs being tracked.
- Bivalent vaccines show better protection against recent Omicron subvariants.
- No significant increase in disease severity associated with XBB.1.16 has been observed.