2015-07-16-世界卫生组织-Influenza_at_the_human-animal_interface_summary_and_assessment,_17_July_2015_4页_353kb

报告摘要

Influenza at the Human-Animal Interface Summary

Core Content

This document provides a summary and assessment of avian influenza A(H5) and A(H7N9) viruses as of 17 July 2015, focusing on human infections and public health risks. It outlines the global and regional status of these viruses, their transmission patterns, and the implications for human health.

Human Infections with Avian Influenza A(H5) Viruses

Key Statistics

Total reported cases: 844 laboratory-confirmed human cases of A(H5N1) virus infection from 16 countries (as of 17 July 2015).
Case fatality rate: Approximately 53% (449 deaths out of 844 cases).
Recent cases:
- Egypt: Two fatal cases were reported:
  - A 40-year-old male with onset on 14 June 2015, hospitalized on 16 June, and died on 22 June.
  - A 5.5-year-old male with onset on 16 June 2015, hospitalized on 24 June, and died on 27 June.
- China: One laboratory-confirmed case of A(H5N6) virus infection was reported:
  - A 37-year-old female from Yunnan province with onset on 6 July 2015, hospitalized on 9 July, and died on 10 July.

Key Information

The likely source of exposure for these cases was either direct contact with poultry or indirect contact with contaminated environments.
Both cases in Egypt received oseltamivir treatment, but it was administered one day after hospitalization.
No evidence of human-to-human transmission was found among close contacts of the A(H5N6) case.
A(H5N6) has been detected in China since 2014, but no human-to-human spread has been observed.

Public Health Risk Assessment

Risk level: Sporadic human infections and small clusters are possible in areas where avian influenza A(H5) viruses are circulating in poultry.
Vigilance needed: Increased monitoring in animal and public health sectors is essential due to the rapid spread of avian influenza outbreaks.
Community awareness: Educating the public about the risks of exposure to infected poultry and contaminated environments is critical to preventing human infections.

Human Infections with Avian Influenza A(H7N9) Viruses

Key Statistics

Total reported cases: 677 laboratory-confirmed cases of A(H7N9) virus infection in China.
Case fatality rate: At least 275 deaths have been reported.
Exposure pattern: Most cases are linked to exposure to infected live poultry or contaminated environments, particularly markets.

Key Information

A(H7N9) viruses continue to circulate in poultry and their environments in regions where human cases have been reported.
No significant genetic changes have been observed in recent isolates compared to earlier ones.
The viruses do not appear to transmit easily from human to human.

Public Health Risk Assessment

Risk level: The public health risk from A(H7N9) viruses remains unchanged since the February 2015 assessment.
Surveillance: Continued monitoring is necessary to detect any changes in transmissibility or infectivity.

Key Influenza A(H5) Subtypes Detected in Birds

Multiple subtypes, including A(H5N1), A(H5N2), A(H5N3), A(H5N6), and A(H5N8), have been identified in birds across West Africa, Asia, Europe, and North America.
While these viruses may pose a risk to humans, no human cases have been reported for most subtypes, except for A(H5N1) and A(H5N6) in China.

Recommendations

Enhance surveillance: Detect human infections early and monitor for any changes in viral behavior.
Increase awareness: Educate communities on the risks of exposure to poultry and contaminated environments.
Improve vigilance: Animal and public health sectors must remain alert to the spread of avian influenza viruses.

Figures

Figure 1: Epidemiological curve of avian influenza A(H5N1) cases in humans by reporting country and month of onset.
Figure 2: Epidemiological curve of avian influenza A(H7N9) cases in humans by week of onset.