The U.S. Department of Agriculture has issued a federal order that requires all dairy cows being transported across state lines to be tested for bird flu. This new order follows the discovery of fragments of the bird flu virus in samples of pasteurized milk found on store shelves by the Food and Drug Administration. In an effort to keep the milk supply safe, farmers were instructed to discard the milk of sick cows and test symptomatic cows. However, the detection of the virus in commercial milk suggests that these measures were not sufficient to contain the spread of the virus. The outbreak has been detected in dairy cows in eight states, raising questions about the extent and duration of the spread.
The H5N1 strain of bird flu, which has been found in the dairy cows, is of concern to scientists and public health officials due to its potential lethality in people. However, there is no evidence that the virus is causing an increase in illness among people or poses an immediate threat to the public. The Centers for Disease Control and Prevention has not identified any unusual influenza-related emergency department visits, even in areas where the virus has been detected among cattle. One dairy worker in Texas was infected with the virus, resulting in mild symptoms. Forty-four other individuals are being monitored for illness.
In response to the outbreak among dairy cows, the USDA’s new mandate requires testing of cows before transporting them across state lines. State veterinary labs are also required to report any positive tests to federal health authorities. Infected cows must undergo a 30-day waiting period before they can be moved and must be retested. There is no concern that the virus could be transmitted to people through drinking milk, as the pasteurization process should eliminate any bacteria or viruses in the milk supply. While the FDA has not completed studies on the effects of pasteurization on the bird flu virus, they have stated that the commercial milk supply is considered safe.
Despite the measures being taken to prevent the spread of the virus among dairy cows, questions remain about the extent of the spread and how long it has been ongoing. Scientists are also investigating where else the virus may have spread and if additional measures are needed to contain it. The FDA plans to release results of studies on the effects of pasteurization on the bird flu virus in the coming days or weeks. The discovery of the virus in the commercial milk supply has raised concerns about the effectiveness of current control measures and the need for further surveillance and intervention to prevent further spread of the virus.
