A man in Mexico, who had pre-existing health conditions, has died after contracting the A(H5N2) strain of bird flu, according to an announcement from the World Health Organization (WHO). The WHO emphasized that the risk to the general public remains low.

The 59-year-old man passed away in Mexico City in April after experiencing symptoms such as fever, shortness of breath, diarrhea, and nausea. His relatives reported that he had been bedridden for three weeks due to other health issues before these acute symptoms emerged. The man's underlying conditions included chronic kidney failure, diabetes, and high blood pressure, as stated by Mexico’s public health department.

The man sought hospital care on April 24 and died the same day. Initial tests revealed an unidentified type of flu, which was later confirmed to be A(H5N2) through lab testing. This marks the first globally reported, laboratory-confirmed human case of A(H5N2) infection.

Andrew Pekosz, an influenza expert at Johns Hopkins University, noted that the man’s prior health conditions increased his risk of severe influenza. However, the source of his infection remains unknown. The WHO mentioned that A(H5N2) cases have been found in poultry in Mexico, including a backyard chicken farm in Michoacan state, near the man’s residence, but no direct connection has been established.

Despite testing those who had contact with the deceased at home and in the hospital, no further human cases have been found. The WHO and Mexico’s Ministry of Health both assess the current risk to the general population as low, with the Ministry of Health confirming that all samples from identified contacts have tested negative.

Authorities are monitoring farms near the man's home and have established a permanent surveillance system to detect other cases in local wildlife. The spread of different bird flu variants, including A(H5N1), has been ongoing among animal species in various countries since 2020. In the US, A(H5N1) was detected in dairy herds in March, with a few human cases reported among farm workers, though these were mild.

Pekosz highlighted the propensity of H5 viruses to infect mammals, emphasizing the need for vigilant monitoring to prevent the virus from accumulating mutations that could enhance human infection. This caution aligns with the historical pattern of H5 viruses since 1997.

A(H5N1) is a highly pathogenic avian influenza virus that has caused outbreaks in birds and sporadic cases in humans. It poses a significant public health concern due to its potential to cause severe illness and death in both poultry and humans. Human infections with A(H5N1) are usually linked to direct contact with infected birds or contaminated environments. While human-to-human transmission is rare, the virus has the potential to mutate and become more easily transmissible among humans, raising concerns about its pandemic potential. Vaccination campaigns in poultry and strict surveillance measures are key strategies for controlling the spread of A(H5N1).