How fragments of the bird flu virus get into milk sold commercially and what the spread of H5N1 in cows means for the dairy industry and milk drinkers

The discovery of Bird flu virus fragments Virus in milk sold in U.S. stores suggests the H5N1 virus could also be more widespread in U.S. dairy cattle than previously thought.

The Food and Drug Administration quickly emphasized that this was the case on April 24, 2024 believes the industrial milk supply is secure. However, the highly pathogenic avian influenza virus can sicken cows, and the influenza virus is present in several states and now in herds latest federal restrictions concerning the movement of dairy cows between states puts economic pressure on farmers.

Five bovine infectious disease experts from the University of California, Davis – Noelia Silva del Rio, Terry Lehenbauer, Richard Pereira, Robert Moller And Todd Cornish – Explain what the test results mean, how bird flu can spread to cattle and the impact this has on the industry.

What are bird flu virus fragments and might they pose a danger to humans?

It is vital to grasp that the presence of H5N1 viral fragments doesn’t indicate the presence of intact virus particles that would cause disease.

The industrial milk supply ensures safety through two decisive measures:

• First, milk from sick animals is promptly diverted or discarded to make sure it doesn’t enter the food chain.

• Second, all milk in grocery stores is heat treated to scale back pathogen exposure to protected levels, primarily through pasteurization. Pasteurization has proven itself Effectively inactivate H5N1 in eggsand this process takes place at a lower temperature than milk.

The virus fragments were also detected quantitative polymerase chain response assays, known for its exceptional sensitivity in detecting even trace amounts of viral genetic material. These fragments are only evidence that the virus was present within the milk. They should not evidence that the virus is biologically lively.

To assess whether the presence of the virus fragments indicates a virus with the flexibility to duplicate and cause disease, a unique testing approach is required. Tests similar to Studies on the viability of embryonic eggs allow scientists to evaluate the virus's ability to duplicate by injecting a sample into an embryonated chicken egg. Such tests are underway.

On April 24, 2024, the FDA announced it had found it no reason to alter his assessment that the milk supply within the USA is secure. The agency strongly advises against consuming raw milk and products constituted of it on account of the chance of contamination with harmful pathogens, including bird flu viruses.

How does a bird flu virus get into cow's milk?

Currently, cows by which H5N1 has been detected have symptoms aside from the standard flu-like symptoms seen in birds.

Abnormal milk and Mastitis, an inflammatory response to infection, are common. Although there is theory that other body secretions similar to saliva, respiratory fluid, urine or feces could also harbor the virus, this has yet to be confirmed.

How waterfowl or other birds transmitted H5N1 to cattle is continues to be being investigated. In 2015 a Outbreak of highly pathogenic bird flu on industrial poultry farms it peaked in April and May, the identical time birds migrated north. Birds can shed the virus through their oral, nasal, urine and fecal secretions. So the virus could potentially be transmitted through direct contact, ingesting contaminated food or water, or inhaling the virus.

Infected dairy cows can excrete the virus through their milk can probably spread it to other cowsbut that also must be proven.

Infectious pathogens that cause mastitis will be transmitted through milking equipment or contaminated milking gloves. Ongoing research will help determine whether this can also be a possible route of transmission for H5N1, and in that case, what causes the virus to thrive on breast tissue.

If H5N1 seems to be widespread in milk, what risks could that pose to the dairy industry?

For the dairy industry, the infection of cattle with the H5N1 avian influenza virus presents challenges on two levels.

The primary concern is at all times the security and health of milk and dairy products.

Existing condition and Federal regulations and industry practice requires that sick cows or cows with abnormal milk be separated in order that their milk doesn’t enter the food supply. Proper pasteurization should kill the virus so it cannot cause infection.

The American Association of Bovine Practitioners has also been founded Biosafety guidelines for H5N1, specializing in key practices. These include minimizing contact of untamed birds with cattle and their environment, controlling livestock movements between farms, isolating affected animals, avoiding feeding unpasteurized (raw) colostrum or milk to calves and other mammals, and ensuring the use of private feed Protective equipment for animals caretakers.

The other major concern is the health of the dairy herd and the people who take care of the dairy cattle. A farm employee caring for dairy cows contracted H5N1 in Texas in March 2024 such cases are rare.

There aren’t any vaccines or specific therapies available against bird flu infections in dairy cows. But following good hygiene and biosecurity practices because each people and cows will contribute to it Reduce the chance of exposure and spread of the bird flu virus amongst dairy cows.

For cows that turn out to be infected with the virus, Providing supportive careIf crucial, fluids and fever-reducing medication can make it easier to get through the illness, which may result in lack of appetite and affect milk production.

Dairy farms affected by an outbreak will suffer economic losses from caring for sick animals and the temporary decline in milk sales. According to initial estimates, around 5 to twenty percent of the animals within the affected herds are sick. Affected animals often recuperate inside 10 to twenty days.

At least 21 states have restricted imports of dairy cattle to stop the spread of the virus and the federal government has announced this require lactating dairy cows to be tested before they will be moved between states starting April 29, 2024. Although the general impact on U.S. milk production is anticipated to be small on an annual basis, there might be short-lived supply disruptions.

How concerned should people be about bird flu?

That of the federal government Surveillance and food safety measuresTogether with pasteurization, they supply vital safety precautions to guard the general public from possible exposure to the avian influenza virus through the food chain.

Drinking raw milk, alternatively, does pose an exposure risk to several diseases, including H5N1. For this reason, the FDA and the Centers for Disease Control and Prevention strongly recommend drinking only pasteurized milk and dairy products.