New rules as avian flu spreads in cattle

With concerns rising about H5N1 avian flu’s spread among cattle herds, the USDA has announced new steps to monitor the situation.

As of Monday, the USDA Animal and Plant Health Inspection Service requires testing of dairy cattle being moved across state lines:

Prior to interstate movement, dairy cattle are required to receive a negative test for Influenza A virus at an approved National Animal Health Laboratory Network (NAHLN) laboratory.Owners of herds in which dairy cattle test positive for interstate movement will be required to provide epidemiological information, including animal movement tracing.Dairy cattle moving interstate must adhere to conditions specified by APHIS.As will be described in forthcoming guidance, these steps will be immediately required for lactating dairy cattle, while these requirements for other classes of dairy cattle will be based on scientific factors concerning the virus and its evolving risk profile.

Reporting of positive tests is also mandatory. Laboratories and veterinarians must report positive Influenza A nucleic acid detection diagnostic results to the APHIS when they are found in livestock, as well as Influenza A serology positives.

So far, the virus is known to spread when cows are in the same herd or near poultry. There are also cases in which cattle moved between dairies have spread the virus, as well as asymptomatic cases.

While a recent test by APHIS found a possible adaptation in the virus for mammals, the Centers for Disease Control and Prevention said that mutation has been seen in other viruses and does not change transmission.

At this time there are no changes that would indicate the virus has become more transmissible to or between people.