US health officials will begin testing ground beef for bird flu amid concerns that the virus could enter commercial meat supply.

Federal health officials have insisted that meat is safe, but there are growing fears  concerned about the virus that has been spotted in commercial milk after tearing through farms across the country.

Three studies conducted by the Department of Agriculture (USDA) will test for particles of avian flu in beef sold in grocery stores or in the muscles of dairy cows sent to slaughter.

The research will also look for evidence that cooking meat thoroughly – opting for a burger well done – will kill the virus.

An ex-FDA food safety expert previously urged DailyMail.com readers to only eat well-done beef and avoid runny eggs while the outbreak rages.

To date, no avian flu has been found in beef cattle. But before last month, it had never been seen in dairy cows either.

In fact, testing on grocery store milk suggested one in five of the products contain the virus, though experts insist the fragments are inactive and cannot infect people who drink the contaminated milk

A USDA official said in a statement: ‘USDA has a rigorous meat inspection process, where USDA's Food Safety and Inspection Service (FSIS) veterinarians are present at all federal livestock slaughter facilities.’

The virus is only active when dairy is not pasteurized, a process that kills harmful bacteria and viruses. The department said the same goes for cooked beef.

Yet some doctors are urging more caution.

Dr Darin Detwiler, former FDA and USDA food safety advisor, told DailyMail.com recently that Americans should avoid rare meat and runny eggs while the outbreak in cattle was ongoing, as improperly cooked animal products are more likely to carry viruses and bacteria.

Avian influenza A (H5N1) first emerged in 1996 but since 2020, the number of outbreaks in birds has grown exponentially, alongside an increase in the number of infected mammals.

The strain has led to the deaths of at least 90 million wild birds and land and marine mammals also infected. The virus was also found in goats, which were previously believed not to be susceptible.

There has also been a case in a Texas farmer, the first human affected in the US. 

Dr Barb Petersen, a dairy veterinarian in Amarillo, Texas, explained that workers at a local farm where cattle have tested positive for the virus are suffering tell-tale symptoms.

She said: 'People had some classic flu-like symptoms, including high fever, sweating at night, chills, lower back pain,' as well as upset stomach, vomiting and diarrhea.

They also tended to have 'pretty severe conjunctivitis and swelling of their eyelids'.

There is some fear that avian flu could transform into a strain that could lead to the next pandemic. 

To be considered a pandemic, it must fulfill three criteria – it spreads easily among humans, primarily through the air, it’s something the immune system has never faced, and it has to cause human disease

Many farmers are in constant contact contact with cows and the flu has been known to infect people at close proximity to animals.

At least half of the more than 900 people who’ve been infected with the virus since 1996 have died.