WHO reports Avian Influenza A(H9N2) outbreak in Vietnam

The World Health Organization (WHO) was notified about a case of human infection with an influenza A(H9N2) virus in Viet Nam on 9 April 2024 by the International Health Regulations (IHR) National Focal Point (NFP).

The patient, who had underlying conditions and was in severe condition was admitted to the intensive care on 21 March 2024.  A respiratory sample was collected on 21 March and tested positive for influenza by Real-Time Polymerase Chain Reaction (PCR). Subsequently, virus subtyping confirmed avian influenza A(H9N2) on 8 April.

Case investigation identified that the case lives near a poultry market, where poultry trade occurs daily in front of his house.  As of 15 April, there have been no reports of new cases with respiratory symptoms among contacts of the case or outbreaks in the community where the case resides.

This is the first human infection with an avian influenza A(H9N2) virus reported in Viet Nam.  According to the IHR (2005), a human infection caused by a novel influenza A virus subtype is an event that has the potential for high public health impact and must be notified to the WHO.  Based on available information, WHO assesses the risk to the general population posed by this virus as low.

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