2015-01-25-世界卫生组织-Influenza_at_the_human-animal_interface_summary_and_assessment,_26_January_2015_5页_387kb

Influenza at the Human-Animal Interface: Summary (as of 26 January 2015)

Human Infection with Avian Influenza A(H5N1) Viruses

From 2003 to January 23, 2015, WHO received reports of 718 laboratory-confirmed human cases of avian influenza A(H5N1) virus infection from 16 countries, resulting in 413 deaths. Between January 6 and 26, 2015, 24 additional cases were reported, including 11 deaths, primarily from Egypt, with disease onset in December 2014 or January 2015. These cases involved exposure to backyard poultry or poultry markets in multiple Egyptian governorates, potentially due to factors like increased viral circulation in poultry, seasonal exposure to cold weather, and longer environmental survival of the virus. Genetic stability of the viruses was noted, with no major changes detected, and community-level transmission risk assessed as low.

Human Infection with Avian Influenza A(H7N9) Viruses

A total of 486 laboratory-confirmed human cases of avian influenza A(H7N9) virus infection were reported to WHO, including 185 deaths, mostly from China and its regions. Cases are predominantly associated with exposure to infected live poultry or contaminated environments. No significant genetic changes were observed, and human-to-human transmission remains unlikely. The overall public health risk assessment has not changed since the October 2014 update, with WHO continuing to monitor the situation.

Overview and Risk Assessment

The increase in H5N1 cases, particularly in Egypt, is linked to poultry outbreaks and environmental factors. No major genetic changes indicate sustained low community spread risk. Ongoing surveillance is emphasized for monitoring virological and epidemiological changes in influenza viruses.