A 59-year-old man in Mexico has died following an infection from a bird flu subtype - it is the first known case of the H5N2 strain infecting a human. There have been about 900 human cases of another strain, H5N1, since 1996 and about half of those people infected died.
Experts say that there is no threat to the wider public and that no one close to the 59-year-old has caught the virus, according to reports. The patient, who died in April, had been hospitalized in Mexico City after developing a fever, shortness of breath, diarrhea, nausea and general discomfort, the World Health Organization (WHO) said on Wednesday.
"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 said in a statement.
While both H5N1 and H5N2 affect farmed birds as well as wild birds, the patient in Mexico had no known exposure to poultry or other animals before he was formally diagnosed with the flu. But he had been bedridden for weeks for other health reasons prior to the infection.
“Due to the constantly evolving nature of influenza viruses, WHO continues to stress the importance of global surveillance,” WHO said in a statement, adding that the current risk to the general population is ‘low’. “This case does not change the current WHO recommendations on public health measures and surveillance of influenza.”
Researchers clarify that the case is unrelated to an outbreak of H5N1 - a different strain from the case in Mexico - in the US that has infected dairy cow herds with four human cases of avian flu having been reported in the US since April 1.