By A Mexico resident died in what officials say is the world’s first death from a bird flu strain not previously detected in humans, the World Health Organization said Wednesday.
The 59-year-old died on April 24 after developing a fever, shortness of breath, diarrhea, nausea and general discomfort a week prior, according to WHO. The victim, who officials did not identify, had multiple underlying medical issues before presenting acute symptoms.
The patient was bedridden in Mexico City for three weeks and later died due to complications from the infection.
Lab results confirmed it was first human death of someone infected with the avian influenza subtype A(H5N2) and the first human H5 virus infection reported in Mexico, per WHO.
The individual had no prior exposure to poultry or other animals and the victim’s source of exposure to the virus is unknown, WHO said.
In Mexico, cases of the A(H5N2) strain of bird flu have been detected in poultry.
At least three bird flu cases in humans the U.S. have been linked to work on dairy farms, but those are a different subtype of the virus (H5N1), health officials have said.
Risk to general population is low
The H5N2 strain differs from the other avian influenza cases that have caused a multi-state outbreak in cattle, since late last year.
WHO officials clarified that the current risk to the general population is low based on available information.
“This case does not change the current WHO recommendations on public health measures and surveillance of influenza,” the organization wrote.
Scientists will conduct an epidemiologic investigation in any case of a “confirmed or suspected human infection caused by a novel influenza A virus with pandemic potential” including the bird flu, according to the WHO. Those experts will also analyze unusual events that could signal person-to-person transmission of the virus and collect clinical samples, the agency said.
What is bird flu?
Bird flu, or avian flu, is a contagious infection that spreads among wild birds and can infect domestic poultry and other animal species. The virus does not often spread to humans but sporadic infections have been reported. There are several strains all belonging to influenza A-type viruses.
The most common subtypes that may affect humans are A (H5N1), A (H7N9) and A (H9N2), according to the Cleveland Clinic.
In humans, symptoms can resemble a typical flu but may advance into more serious respiratory symptoms.
In birds, avian flu is highly contagious and cases can range in severity from mild to highly deadly. Infected birds shed the viruses in their saliva, nasal secretions and feces, meaning other birds can contract the virus through contact with those fluids directly or via contact with a contaminated surface.
The CDC has documented three cases of human bird flu infections in 2024, two in Michigan dairy farm workers and one in a dairy farm worker from Texas.
Contributing: Mary Walrath-Holdridge
