The World Health Organisation (WHO) has confirmed the death of a man in Mexico after he contracted the avian influenza A(H5N2) virus.
It was the first laboratory-confirmed human case of infection with an influenza A(H5N2) virus reported globally and the first avian H5 virus infection in a person reported in Mexico.
On May 23, 2024, the Mexico International Health Regulations (IHR) National Focal Point (NFP) reported to WHO a confirmed fatal case of human infection with avian influenza A(H5N2) virus detected in a resident of the State of Mexico who was hospitalized in Mexico City.
Although the source of exposure to the virus in this case is currently unknown, A(H5N2) viruses have been reported in poultry in Mexico.
Based on available information, the WHO assessed the current risk to the general population posed by this virus as “low”.
The deceased was a 59-year-old who was hospitalized in Mexico City and had “no history of exposure to poultry or other animals,” according to the WHO.
The organisation confirmed the case had multiple underlying medical conditions. The case’s relatives reported that the case had already been bedridden for three weeks, for other reasons, prior to the onset of acute symptoms.
No further cases were reported during the epidemiological investigation. Of the 17 contacts identified and monitored at the hospital where the case died, one reported a runny nose between 28 and 29 April.
In March 2024, a high pathogenicity avian influenza A(H5N2) outbreak was detected in a backyard poultry farm in the state of Michoacán, which borders the State of Mexico where the case was residing.
Additionally, in March 2024, an outbreak of low pathogenicity avian influenza (LPAI) A(H5N2) was identified in poultry in Texcoco, State of Mexico, and a second outbreak of LPAI A(H5N2) in April in the municipality of Temascalapa in the same state.
Thus far, the WHO has stated “it has not been possible to establish if this human case is related to the recent poultry outbreaks”.
Avian influenza
Animal influenza viruses normally circulate in animals but can also infect humans.
Infections in humans have primarily been acquired through direct contact with infected animals or contaminated environments.
Depending on the original host, influenza A viruses can be classified as avian influenza, swine influenza, or other types of animal influenza viruses.
Avian influenza virus infections in humans may cause mild to severe upper respiratory tract infections and can be fatal.
Conjunctivitis, gastrointestinal symptoms, encephalitis and encephalopathy have also been reported.