Bird Flu Found High in Milk of Infected Cows, Raising Concerns About Spread to Humans

The World Health Organization (WHO) has reported that the H5N1 avian influenza virus is present at high levels in the milk of infected cows. While experts are still studying how long the virus can persist in milk, initial findings suggest that it is highly concentrated in raw milk.

This news comes after a recent case in Texas, USA, where a person contracted bird flu after coming into contact with infected dairy cows earlier in the month. This is the second case of A/H5N1 influenza in humans in the US and highlights growing concerns about the spread of the virus to new hosts.

The Texas Department of Health Services has assured that while cattle infected with the virus pose no threat to commercial milk supply, any infected cows’ milk must be destroyed. The virus can be killed through pasteurization, which Ms. Wenqing Zhang, head of global influenza program at WHO, emphasized as crucial for maintaining food safety through pasteurized dairy products.

Since its emergence in 1996, avian influenza A/H5N1 has caused numerous outbreaks among birds and mammals worldwide. While cases of H5N1 in Europe or the US typically feature mild symptoms, there have been severe cases globally. As of April 1st, 2021, WHO has recorded 463 deaths and 889 cases of H5N1 infection among humans across 23 countries worldwide, with a mortality rate of 52%. There is currently no evidence of human-to-human transmission of H5N1, primarily spreading through contact with infected animals. Nearly 20 vaccines are available for A/H5N1 influenza should a pandemic occur and adaptable to specific virus strains.