2022-01-20-世界卫生组织-Influenza_at_the_human-animal_interface_summary_and_assessment,_21_January_2022_5页_219kb

Influenza at the Human-Animal Interface Summary and Risk Assessment (December 14, 2021 – January 21, 2022)

New Infections

From December 14, 2021, to January 21, 2022, official reports included one human case of influenza A(H5N1), nine human cases of influenza A(H5N6), and five human cases of influenza A(H9N2) infections.

Risk Assessment

• The overall public health risk from known influenza viruses at the human-animal interface remains unchanged.
• Sustained human-to-human transmission of these viruses is unlikely, though sporadic human infections are expected where animal viruses circulate.
• For A(H5), Europe continues to detect viruses, with one British case.
• For A(H7N9), no recent animal infection reports.
• For A(H9N2), further human cases are expected due to ongoing poultry circulation.

Specific Virus Details

Avian Influenza A(H5)

• Reports: One human case in the UK (asymptomatic H5N1); Europe has persistent detection of H5N1 and H5N8 viruses.
• Risk: Expected additional cases due to animal/virus contact; no sustained human transmission.

Avian Influenza A(H5N6)

• Cases: Nine reported in China, mostly with severe conditions; no epidemiological links; viruses spread via poultry exposure.

Avian Influenza A(H7N9)

• No recent public reports of animal infections; risk assessment unchanged.

Avian Influenza A(H9N2)

• Cases: Five in China, typically mild; detected in environmental samples; expected more cases from poultry contact.

Risk Management Recommendations

• WHO advises against special traveler screening but recommends avoiding animal contact and practicing good hygiene.
• Maintain global surveillance and collaboration between animal and human health sectors.
• Under COVID-19, continue vigilance for novel influenza viruses and prepare for upcoming influenza seasons.
• All new influenza subtypes are subject to IHR notifications.

IHR Compliance and Surveillance

• All laboratory-confirmed cases of new influenza subtypes must be reported per IHR(2005).
• Viruses with pandemic potential should be shared with WHO’s Global Influenza Surveillance and Response System for risk assessment.

For more details, refer to WHO and OIE resources on avian influenza and human-animal interface, including surveillance protocols and cumulative case data.