The US Food and Drink Administration (FDA) has confirmed that some pasteurised milk samples have “indicated the presence” of the Highly Pathogenic Avian Influenza (HPAI), commonly known as bird flu.
According to the FDA, pasteurisation is likely to inactivate the bird flu virus but the process is “not expected to remove the presence of viral particles”.
The US Department of Agriculture (USDA), the FDA and the Centers for Disease Control and Prevention (CDC), along with state partners are currently investigating an outbreak of the bird flu virus detected in dairy cows in a number of states.
Earlier this month, the CDC confirmed that a person in the US who had contact with dairy cattle in Texas infected with bird flu had has also tested positive for the virus.
The individual reported eye redness as their only symptom and the CDC has said the risk to the general public remains low.
The FDA and USDA have both stressed that based on the information currently available, commercial milk supply in the US is safe because of “the pasteurization process and the diversion or destruction of milk from sick cows”.
The FDA highlighted this week that it has been “evaluating milk from affected animals”, in the processing system, and on the shelves.
“We are completing a large representative national sample, to better understand the extent of these findings.
“To date, we have seen nothing that would change our assessment that the commercial milk supply is safe,” the organisation stated.
It added that because the detection of the virus in dairy cows is a “novel and evolving situation” no studies on the effects of pasteurisation on HPAI viruses (such as H5N1) in “bovine milk have previously been completed although considerable scientific literature is available that has informed our current understanding”.
Bird flu
Meanwhile the CDC has indicated that its latest research suggests that the bird flu virus is “susceptible” to antiviral medications used for seasonal flu such as oseltamivir, zanamivir and peramivir.
It said laboratory investigations are continuing “to better characterise the virus from the human case in Texas”.
The CDC has warned that the wide geographic spread of bird flu viruses in wild birds, poultry, and some other mammals, including in cows, is “creating additional opportunities for people to be exposed to these viruses”.
It added: “Therefore, there could be an increase in sporadic human infections resulting from bird, cattle, and other animal exposures, even if the risk of these viruses spreading to people has not increased”.