2015-12-13-世界卫生组织-Influenza_at_the_human-animal_interface_summary_and_assessment,_14_December_2015_3页_244kb

Summary of Human Infections with Avian Influenza at the Human-Animal Interface as of 14 December 2015

Avian Influenza A(H5) Viruses

Since the last WHO report on 13 November 2015, no new laboratory-confirmed human cases of avian influenza A(H5N1) virus infection have been reported. Total cases reported to WHO from 2003 to 14 December 2015 include 844 confirmed cases across 16 countries, with 449 deaths. Various A(H5) subtypes (e.g., H5N1, H5N6) have been detected in birds in Africa, Asia, and Europe, but no widespread human cases except for H5N1 and a few H5N6 cases in China. No cases with other A(H5) subtypes reported. In France, high-pathogenicity H5 viruses were detected in birds, with one virus of unknown origin relative to existing human cases. WHO maintains the same public health risk assessment since July 2015.

Avian Influenza A(H7N9) Viruses

Since the last update on 13 November 2015, two new laboratory-confirmed cases of A(H7N9) virus infection were reported from China, involving exposure to domestic poultry. Cumulative cases since 2013 total 683 confirmed infections, with at least 275 deaths. The virus persists in animal populations in multiple Chinese provinces, leading to an expected increase in human cases in affected and possibly neighboring areas. WHO maintains its risk assessment unchanged since February 2015.

Avian Influenza A(H9N2) Viruses

Since the last update, four laboratory-confirmed cases of A(H9N2) virus infection were reported from China, all with mild symptoms and no hospitalizations. Cumulative cases are not specified, but the virus circulates in poultry in Asia and the Middle East, with potential for more cases, though human-to-human transmission is limited and disease is typically mild. WHO assesses the public health risk as low.

Overall Assessment and Recommendations

WHO continues to emphasize global surveillance for zoonotic influenza viruses due to their evolving nature, especially during flu seasons. All non-seasonal influenza human infections are reportable under IHR(2005). Viruses should be fully characterized and reported internationally to monitor public health risks.