The Agriculture Department is set to launch a significant testing program next week. This program aims to detect the bird flu virus in fresh milk from farms, providing a clearer understanding of the prevalence of the H5N1 virus among U.S. dairy herds. The efforts are part of an ongoing battle to identify infected herds and halt the spread of the virus.

Enhancing Safety and Confidence

Agriculture Secretary Tom Vilsack emphasized that this testing will give farmers and farmworkers greater confidence in the safety of their animals and their ability to protect themselves. It puts the nation on a path to quickly controlling and stopping the virus's spread nationwide. As of now, around 58 people have contracted bird flu this year, with nearly all cases among dairy and poultry workers on infected farms. Public health officials have stated that there have been no cases of person-to-person spread, and the virus has not evolved to become more communicable.

State-by-State Impact

Since late March, bird flu has been confirmed in 720 dairy herds across 15 states. California, the leading dairy state, has 502 infected herds. On Friday, state agriculture officials reported that 20 farms have fully recovered and been released from quarantine. These farms will be placed on a surveillance list and undergo weekly testing through creameries to maintain continuous monitoring of the virus in California. Additionally, tests will begin in the week of Dec. 16, with California, Colorado, Michigan, Mississippi, Oregon, and Pennsylvania as the initial participants. Samples will be taken from farms or businesses transporting milk for pasteurization. Results will be reported each Friday. In addition to California, bird flu has been confirmed in 64 herds in Colorado and 29 herds in Michigan. The other three states have remained free of the virus.

Contact Tracing and Surveillance

Dairy farmers with infected herds are required to provide epidemiological information to assist in contact tracing and disease surveillance. Private laboratories and state veterinarians are also obligated to report when the H5N1 virus is found in milk samples as part of the new National Milk Testing Strategy (NMTS). The first step in the NMTS is testing milk at processing plants, followed by testing from bulk storage tanks. Then, individual infected herds are identified for response measures such as enhanced biosecurity, contact tracing, and controls on cattle movement. Once all dairy herds in a state are considered unaffected, the Animal and Plant Health Inspection Service will continue regular sampling of farms' bulk tanks to ensure the disease does not re-emerge. When all states are free of bird flu in dairy cattle, APHIS will work with states to start periodic testing to demonstrate the long-term absence from the national herd.

Raw Milk and Public Health

In late November, bird flu virus was found in whole raw milk for sale in Santa Clara County in California's Silicon Valley. While most milk is pasteurized, which kills the virus, more than 30 states allow the sale of raw milk. About 1% of U.S. adults consume raw milk weekly. President-elect Donald Trump's choice to lead the Department of Health and Human Services, Robert Kennedy Jr., has expressed a desire to end the FDA's "aggressive suppression" of raw milk. Since 1987, the FDA has prohibited the distribution of unpasteurized milk across state lines due to concerns about bacteria that can cause illness.

Researchers have emphasized the significance of continuous surveillance of emerging mutations in avian and bovine clade 2.3.4.4b H5N1 viruses. A single mutation in the H5N1 avian influenza virus could potentially enhance its ability to attach to human cells, raising concerns about the possibility of transmission among humans.

Unraveling the Risks of Bird Flu Mutations

Research Insights on H5N1 Virus

There has been no clear evidence of person-to-person spread of bird flu so far. However, a study led by scientists at the Scripps Research Institute has revealed that a single mutation in the H5N1 virus could lead to enhanced attachment to human cells. This finding highlights the need for constant monitoring of such mutations. As stated in the journal Science, these mutations could potentially pose a greater risk in the future.

Public health officials have been conducting genomic analyses of the H5N1 virus and have found no changes that would make it more communicable among humans. They advise people to take necessary precautions such as wearing protective gear when in contact with infected or potentially infected animals. In the United States this year, there have been 58 human cases of bird flu, with most among livestock workers and all being mild.

Avian flu viruses typically require several mutations to adapt to humans. But a single amino acid mutation in hemagglutinin, which binds the virus to receptors on host cells, could allow the bird flu virus circulating among cattle to attach to human-like receptors. The Scripps scientists have demonstrated that the virus could easily evolve to recognize human-type receptors, but it doesn't mean the current H5N1 virus would be transmissible if it acquired the mutation.

California's Bird Flu Outbreaks

The California agriculture department has identified 11 new outbreaks, and since late August when the virus was detected, 504 dairy herds in the state have been infected. There are approximately 1,100 dairy herds in California. This shows the widespread impact of the bird flu virus in the region.

Raw Farm's Recall and FDA Application

Raw Farm has recalled its unpasteurized whole milk and cream products due to the possibility of containing the bird flu virus. The chief executive, Mark McAfee, has applied for the position of "FDA adviser on raw milk policy and standards development" in the incoming Trump administration. He was encouraged to do so by the transition team for Robert F. Kennedy, nominated by President-elect Donald Trump to head the Department of Health and Human Services. This shows the intersection of the bird flu issue with regulatory and policy matters.