World Health Organisation (WHO) says Mexico has reported the first-ever laboratory-confirmed human case of the H5N2 avian influenza (bird flu).

Bird flu is a condition caused by an influenza virus that is generally observed among wild aquatic birds.

It can also infect domestic poultry, other birds, and animals. Bird flu infections in humans, though possible, are rare.

There are many strains of bird flu — one of which is the H5N2 strain.

In a statement on Wednesday, the WHO said the Mexico International Health Regulations (IHR) national focal point (NFP) reported the case on May 23.

The WHO said the human case was a 59-year-old resident who had developed a fever, shortness of breath, diarrhoea, nausea, and general discomfort.

The global health agency added that the victim had no history of exposure to poultry or other animals but had multiple underlying medical conditions.

“Although the source of exposure to the virus in this case is currently unknown, H5N2 viruses have been reported in poultry in Mexico,” the statement reads.

“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.

“On April 17 April, the case developed fever, shortness of breath, diarrhoea, nausea and general malaise.

“On 24 April, the case sought medical attention, was hospitalized at the National Institute of Respiratory Diseases ‘Ismael Cosio Villegas’ (INER per its acronym in Spanish) and died the same day due to complications of his condition.”

The WHO said this is the first laboratory-confirmed human case of the H5N2 virus reported globally.

“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,” the organisation said.

In March 2024, 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.

Also in the same month, an outbreak of H5N2 was identified in poultry in Texcoco, a Mexican state, and a second outbreak of H5N2 in April in Temascalapa, in the same state.