The World Health Organization (WHO) has confirmed the world’s first laboratory-confirmed human death from a subspecies of bird flu in Mexico.

A 59-year-old person died in Mexico City on April 25 after being infected with the A(H5N2) virus, the WHO said in a statement on Wednesday. The affected person was admitted to hospital due to fever, shortness of breath, diarrhea, nausea and malaise.

It is unknown how the person became infected. However, evidence of the virus in poultry has been reported in Mexico, the WHO reported. In March, an A(H5N2) outbreak was detected in a backyard poultry farm in the state of Michoacán – which borders the state of Mexico, where the infected person lived.

“Based on the available information, WHO assesses the current risk to the general population from this virus as low,” the WHO said. The infected person had several underlying medical conditions and had not been in contact with poultry or other animals.