Bird flu antibodies detected in cow in the Netherlands

Following the death of a cat on a farm in the Netherlands, a dairy cow was found to have bird flu antibodies in her milk, indicating a previous infection of the disease

A dairy cow was found to have bird flu antibodies in her milk.

A dairy cow in the Netherlands was found to have bird flu antibodies detected in her milk, the first detected case outside of the US.

Following the death of a cat on a dairy farm in the Friesland province, which was found to have been infected by Highly Pathogenic Avian Influenza (HPAI) H5N1, subsequent testing of the cattle on the farm was conducted.

In a letter to the House of Representatives in the Netherlands, agriculture minister Femke Marije Wiersma said screening on the farm was conducted on January 15 and found one cow in the herd with HPAI antibodies in her milk, flagging the cow as having once contracted the virus. There was no evidence of an active infection within the herd.

Reportedly, the cow in question had experienced mastitis and respiratory problems in December. Due to the mastitis problems, the cow’s milk was not processed for human consumption.

A second round of testing returned negative PCR results for the virus, apart from five tests which had to be discarded due to a testing error in the laboratory — those five animals will be retested in due course.

“Based on the PCR results known so far… There is no indication of active avian influenza virus circulation among the dairy cattle on the farm,” the minister said.

The minister highlighted that as long as milk is pasteurised, an infected animal’s milk is safe for human consumption. Raw or unpasteurised milk from an animal that is infected with HPAI should not be consumed.

Assistant professor of virology at University College Dublin (UCD), Dr Gerald Barry said: "There is no clinical reason to suspect that cattle are currently being infected by avian influenza, but the possibility of it occurring in the future can not be ruled out.” 

"In Ireland, currently, there is a study ongoing within the Department of Agriculture, Food and the Marine, testing blood samples from cattle collected a couple of years ago for the presence of avian influenza antibodies.

"This is a retrospective study to see if those animals were positive and will provide a look back to see if cattle before now are likely to have been infected. Results from this study are expected later this year,” he added.

Lecturer at School of Biological Sciences at Queen's University Belfast Dr Connor Bamford said: "Given that the island of Ireland is at continuous risk of avian influenza, and that we have a high density of cattle, these results reinforce the importance of 1) preventing spillover of virus from birds to cows; and 2) being able to detect and monitor infections if they do occur. Currently, neither of these is really being undertaken in Ireland."