A man’s death in Mexico was caused by a strain of bird flu called H5N2 that has never before been found in a human, the World Health Organisation (WHO) announced on Wednesday evening.
The H5N2 strain has previously been reported in poultry but the 59-year-old who was hospitalised in Mexico City had not been in contact with infected chickens or other animals.
“Although the source of exposure to the virus in this case is currently unknown, A(H5N2) viruses have been reported in poultry in Mexico,” WHO wrote in a statement.
“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 current risk to the general population posed by this virus as low.
There are numerous types of bird flu. H5N2 is not the same as the H5N1 strain that has resulted in three farm workers in the United States becoming ill in recent months.
Other bird flu varieties have killed people across the world in previous years, including 18 people in China during an outbreak of H5N6 in 2021, according to a timeline of bird flu outbreaks from the US.
According to family members, the WHO statement read, the patient had been bedridden for unrelated reasons before developing a fever, shortness of breath and diarrhea on April 17. Mexico’s public health department said in a statement that he had underlying ailments, including chronic kidney failure, diabetes and high blood pressure.
Hospital care was sought on April 24 and the man died the same day.
Initial tests showed an unidentified type of flu that subsequent weeks of lab testing confirmed was H5N2.
No further human cases have been discovered so far despite testing people who came in contact with the deceased at home and in the hospital.
There had been three poultry outbreaks of H5N2 in nearby parts of Mexico in March but authorities haven’t been able to find a connection. Mexican officials also are monitoring birds near a shallow lake on the outskirts of Mexico City.
Whenever bird flu circulates in poultry, there is a risk that people in close contact with flocks can become infected. Health authorities are closely watching for any signs that the viruses are evolving to spread easily from person to person, and experts are concerned as more mammal species contract bird flu viruses.