Originally a harmless virus in wild birds, a new strain of bird flu has claimed its first human life in Mexico, prompting the World Health Organization (WHO) to intensify its monitoring efforts.
Media reports indicate that the man had no known contact with animals before falling ill. But Björn Olsen, a professor of infectious diseases at Uppsala University, finds this unlikely and suspects the man must have had some brief contact with animals.
"He might have walked through a chicken coop or a flock of birds and got infected that way. There's no other plausible explanation," says Olsen.
Since 2003, nearly 900 people worldwide have been infected with the bird flu virus, with over 50 percent of those cases resulting in death.
The WHO has warned of the severe consequences of the spread of bird flu viruses, especially the H5N1 type, which has a fatality rate exceeding 50 percent.
The H5N2 virus has spread in recent years. First perceived as harmless in wild birds, it became more aggressive and dangerous after infecting domestic bird flocks and then spreading back into the wild.
On April 24, a 59-year-old man in Mexico died after experiencing acute diarrhea, fever, and shortness of breath, marking the first human death from this new strain of bird flu.