2022-11-10-世界卫生组织-Influenza_at_the_human-animal_interface_summary_and_assessment,_11_November_2022_6页_230kb

Summary of Influenza at Human-Animal Interface (October 6-11, November 11, 2022)

New Infections

From October 6 to November 11, 2022, the World Health Organization reported official human cases of influenza viruses at the human-animal interface. Key infections included:

• One case of influenza A(H5) in Viet Nam.
• Three cases involving avian influenza A(H5N1): one in Spain, one in Viet Nam, and one in China.
• One case of influenza A(H9N2) in China.
• One case of influenza A(H1N1) variant in Brazil.
• One case of influenza A(H1N2) variant in the Netherlands.
• Two cases of influenza A(H3N2) variant in the United States, both in individuals under 18 years old.

Overall Risk Assessment

The overall public health risk from currently known influenza viruses at the human-animal interface has not changed. The likelihood of sustained human-to-human transmission remains low for all viruses. Human infections are expected due to direct or indirect contact with infected animals or contaminated environments.

Specific Virus Risks

• Avian Influenza A(H5) Viruses: High expected cases due to persistence in animals; no evidence of sustained human-to-human transmission. Travel-related spread possible, but further community spread unlikely.
• Avian Influenza A(H9N2) Viruses: Expected more human cases from poultry exposure, typically mild; low sustained transmission risk. Virus enzootic in Asia and increasing in Africa.
• Swine Influenza Viruses: Human cases from accidental animal contact, generally mild; low sustained transmission risk. Expected more cases as viruses circulate.

Recommendations and Actions

• WHO advises no special traveler screenings or restrictions. Travelers should avoid contact with farms, live animal markets, and sick animals; practice good hygiene, including handwashing.
• Public should strictly avoid contact with sick or dead birds, especially wild birds. Report dead birds to authorities.
• Global surveillance is critical due to evolving viruses, with continued vigilance in affected areas and collaboration between animal and human health sectors.
• All new influenza subtypes are notifiable under the IHR (2005); sharing virus data supports pandemic risk assessment and vaccine development.