2014-10-01-世界卫生组织-Influenza_at_the_human-animal_interface_summary_and_assessment,_2_October_2014_3页_322kb

报告摘要

Influenza at the Human-Animal Interface Summary

Core Content

This document provides an overview of human infections with various avian influenza viruses as of 2 October 2014, with a focus on the public health risk assessments for these viruses. It outlines the status of outbreaks in both animals and humans, highlighting the potential for transmission between species and the importance of global surveillance.

Key Information

Avian Influenza A(H5N1):
- From 2003 to 2 October 2014, 668 laboratory-confirmed human cases were reported to WHO from 16 countries, with 393 deaths.
- One new case was reported in Egypt in September 2014, involving a 2.5-year-old girl who had contact with backyard poultry.
- The overall public health risk assessment indicates that sporadic human infections or small clusters may occur when H5N1 viruses are circulating in poultry, especially among those exposed to infected birds or contaminated environments.
- Transmission between humans is not currently efficient, and the risk of community-level spread remains low.
Avian Influenza A(H5N6):
- A single human case was reported in April 2014 in Sichuan, China, with likely exposure to infected poultry.
- Outbreaks in poultry due to H5N6 have been reported in China, Lao PDR, and Vietnam.
- The risk assessment suggests that further sporadic human cases or small clusters may occur due to the widespread presence of H5N6 in poultry populations.
- Close monitoring of both human and animal populations is recommended to better understand the potential public health impact of H5N6.
Avian Influenza A(H7N9):
- WHO is closely monitoring the situation in China, where H7N9 has been detected in humans.
- Specific risk assessments and updated information are available on the WHO website.
Influenza A(H3N2)v:
- Two cases were reported in the USA in August 2014, both involving close contact with swine.
- Both patients recovered fully, and no human-to-human transmission was identified.
- The risk assessment indicates that further human cases and small clusters may be expected due to the virus's circulation in swine and its association with agricultural fairs during the summer.

Public Health Risk Assessment Summary

H5N1: Human infections remain rare, and the virus does not transmit easily between people. The risk of community-level spread is low.
H5N6: While the human case appears isolated, the virus's presence in poultry suggests a potential for further sporadic infections. Continued monitoring is essential.
H7N9: The virus has been associated with outbreaks in humans and animals, and its emergence has led to enhanced surveillance. Risk assessments are ongoing.
H3N2v: The virus is circulating in swine and has been linked to human infections through close contact. The risk of community spread is considered low.

Surveillance and Monitoring

The number of avian influenza outbreaks in birds is consistent with the expected level for this time of year.
The emergence of H7N9 has prompted increased surveillance for non-seasonal influenza viruses in both humans and animals.
WHO emphasizes the importance of global surveillance to detect changes in influenza viruses that may affect human or animal health.
All human infections with non-seasonal influenza viruses must be reported to WHO under the IHR (2005).
Full characterization of influenza viruses from animals and humans is critical and should be conducted in appropriate reference laboratories.