In a meeting on April 19, Ms. Wenqing Zhang, head of the global influenza program at WHO, revealed that the H5N1 avian influenza virus had been detected in the milk of infected cows at very high concentrations. The discovery has raised concerns about the longevity of the virus in this environment and prompted experts to investigate further.
Ms. Zhang highlighted a case in Texas, where a person contracted bird flu after contact with infected dairy cows. The concern raised by Ms. Zhang is that the virus is beginning to infect mammals, increasing the likelihood of transmission to humans. While the Texas Department of Health Services assured that milk from infected cows was destroyed and pasteurization would kill the virus, Ms. Zhang emphasized the importance of food safety, urging the consumption of pasteurized dairy products.
Since its appearance in 1996, the H5N1 virus has caused millions of deaths in poultry, wild birds, and terrestrial and marine mammals. Although the virus primarily infects animals, there have been 889 cases of human infection in 23 countries, resulting in 463 deaths. The mortality rate from H5N1 infection stands at 52%, significantly higher than the typical influenza mortality rate of 1-4%. Fortunately, there is currently no evidence of human-to-human transmission of the virus, primarily spreading through contact with infected animals. In preparation for a potential pandemic, there are nearly 20 licensed vaccines available, tailored to specific virus strains.
