2024-06-06-世界卫生组织-Influenza_at_the_human-animal_interface_summary_and_assessment,_7_June_2024_10页_293kb

报告摘要

Influenza at the Human-Animal Interface: Summary and Risk Assessment (May 4 to June 7, 2024)

Overview

Between May 4 and June 7, 2024, multiple human infections with influenza viruses, including zoonotic variants, were reported globally. These viruses circulate in animals, primarily birds, and are monitored for pandemic potential. Human cases are sporadic, often linked to animal contact, with no evidence of sustained human-to-human transmission or large-scale community spread currently.

Summary of Human Infections by Virus

Influenza A(H5N1): Four human cases reported, including from Australia (a child exposed in India), China (a cargo worker from Vietnam), and the USA (two dairy workers with severe cases). Australian case involved clade 2.3.2.1a, following exposure in bird-infection areas. Cases were mild to severe, but all recovered, linked to animal contact.
Influenza A(H5N2): One human case from Mexico (adult with multiple comorbidities and exposure to poultry) caused death, marking the first global laboratory-confirmed human infection with this subtype.
Influenza A(H5N6): Two human cases from China (both adults with severe illness, linked to backyard poultry exposure) resulted in fatalities.
Influenza A(H9N2): Three human cases: two from China (mild illness, exposure to poultry) and one from India (severe but recovered respiratory illness). Infections ranged from mild to severe but did not involve sustained spread.

Risk Assessment for Zoonotic Influenza Viruses

Overall Public Health Risk: Low risk for widespread human transmission. Viruses are primarily spread through animal contact, and sporadic human cases are expected due to ongoing animal circulation. No sustained human-to-human transmission has occurred recently or been confirmed.
Likelihood of Pandemic: While viruses may evolve, current evidence indicates limited transmissibility. If transmission evolves, the impact could be assessed through surveillance and vaccine development.
International Spread: Enhanced surveillance at borders may detect cases, reducing the chance of community-level spread unless infections bypass early detection.

Animal Circulation and Zoonotic Potential

High-pathogenicity avian influenza (HPAI), particularly A(H5) viruses, continues to circulate in poultry and non-poultry animals, reported via systems like WOAH and FAO.
Monitoring includes surveillance in birds, livestock, and wild animals with biosecurity measures to prevent spread. Non-human mammal infections are also documented.

Surveillance and Recommendations

Strengthen global and local surveillance in humans and animals, including病例reporting under IHR (2005).
Investigate outbreaks systematically, ensure laboratory confirmation, and share genetic data for risk assessments.
Key actions: Prevent person-to-animal contact at risk, avoid raw animal products, practice good hygiene for travellers, and limit biosecurity risks in agriculture.
No special traveller restrictions advised, but heightened awareness is essential for those in affected regions.