WHO confirms first fatal human case of H5N2 bird flu

A 59-year-old resident of the State of Mexico has died from bird flu in the first confirmed case of a human infected with the H5N2 variant, the World Health Organization (WHO) announced on Wednesday. The patient passed away on April 24 after experiencing fever, shortness of breath, diarrhea, and nausea. Despite having no history of exposure to poultry or other animals, the individual had multiple underlying medical conditions, including chronic kidney disease and type 2 diabetes, according to a statement from Mexico's health ministry.
The WHO reported that the patient, who had been bedridden for three weeks prior to developing acute symptoms, was hospitalized in Mexico City and succumbed to the illness the same day.This case marks the first laboratory-confirmed human infection with an influenza A(H5N2) virus globally and the first avian H5 virus reported in a person in Mexico.
"Although the source of exposure to the virus in this case is currently unknown, A(H5N2) viruses have been reported in poultry in Mexico," the WHO said. Mexican health authorities conducted laboratory tests and reported the confirmed case to the UN health body on May 23.
In March, H5N2 cases were detected in a backyard poultry farm in Michoacan state, with other outbreaks identified in the State of Mexico. However, establishing a link between the human case and the poultry infections has been challenging. The WHO estimates the risk to the general population as "low."
The Mexican health ministry emphasized that there is no risk of contagion for the population, noting that all samples from identified contacts of the patient have tested negative. Authorities are closely monitoring farms near the victim's home and have set up a permanent monitoring system to detect other cases in wildlife in the area.
Andrew Pekosz, an influenza expert at Johns Hopkins University, highlighted the complexity of the situation, saying, "How this individual got infected is a big question mark that at least this initial report doesn't really address thoroughly."
The WHO and Mexican health officials continue to investigate the source of the infection. Bird flu has been known to infect various mammals, including seals, raccoons, bears, and cattle, primarily due to contact with infected birds. Scientists remain vigilant for changes in the virus that could signal its adaptation to spread more easily among humans.
In the United States, a different variant of bird flu, H5N1, has been spreading among dairy cow herds, with a small number of human cases reported. However, none of these cases involved human-to-human transmission.
Australia also reported its first human case of A(H5N1) infection in May, with no signs of transmission, while noting more poultry cases of H7 bird flu on farms in Victoria state.
Pekosz added, "Since 1997, H5 viruses have continuously shown a propensity to infect mammals more than any other avian influenza virus. So it continues to ring that warning bell that we should be very vigilant about monitoring for these infections, because every spillover is an opportunity for that virus to try to accumulate those mutations that make it better infect humans."
(With inputs from agencies)