British-grown pork livestock has been tested positive for livestock associated MRSA, the Guardian reports. The tests were carried out by Dr Mark Holmes, director of studies in clinical veterinary medicine at Churchill College, Cambridge University, and commissioned by the Alliance to Save Our Antibiotics, founded by the Soil Association, Compassion in World Farming and Sustain.

Image credits Tanakawho / Flickr.

Out of a sample of 97 UK-grown-pork products purchased from British supermarkets, three items — sourced from Asda and Sainsbury’s — were contaminated with MRSA CC398, a livestock strain of the superbug, the publication reports. Working with the Bureau of Investigative Journalism (BIJ), the Guardian has identified the most likely source of the infection in import-legislature loopholes. Through these, pigs from countries where the bacteria is rampant, such as Denmark, have been imported to the UK without proper precautions.

And that’s really bad news.

While MRSA CC398 isn’t as harmful to us as the human-specific strains, it’s still a potentially deadly bacteria that can resist almost everything we can throw at it. Research has found that combining three previously-efficient drugs together can serve as a sort of stop-gap measure against the bacteria; there’s also a thousand year-old salve that’s shown some potential agains MRSA, and Canadian clay. And that’s it.

About 300 people die each year as result of MRSA infection in England and Wales alone, and the bug seriously threatens patients with weakened immune systems.

“MRSA infections kill 11,000 people each year in the United States, and the pathogen is considered one of the world’s worst drug-resistant microbes,” said Gautam Dantas, PhD, an associate professor of pathology and immunology at the Washington University School of Medicine, unaffiliated with the publication.

Still, six cases of MRSA CC398 death have been confirmed in Denmark so far, but there are probably a lot more, the Guardian reports. Animals can catch the bacteria from infected pigs, and people can contract it from eating infected meat or from working with infected animals. Thoroughly cooking it should destroy the germs, but a small risk remains.

The publication warns that UK pigs might be in for the same fate as Denmark’s, where MRSA CC389 spread over a decade ago and now afflicts two-thirds of farms. It’s a major health issue for the country, with some 12,000 people believed to have contracted it — and there are no screening programs set in place for danish pigs.

“If we don’t have tight infection control and we don’t try to control the movement of live animals, infection can spread. The British are up in arms about the movement of people, but the EU also has a large movement of animals,” said Prof Tim Lang from the Food Policy at City University, London.

“We need biosecurity, we need to tighten up this livestock movement. You may get cheap meat, but in the long term it’s going to add to your public health problems.”

The real issue here, just like with human-specific MRSA, is the drug resistance part. What most people don’t understand is that it’s not limited to humans — it’s happening in agriculture, too. The rise of the CC398 strain can in part be attributed to an overuse of antibiotics in factory farming, where cramped and dirty conditions allows disease to flourish. Farmers are left with little choice but feed their livestock huge amounts of antibiotics, promoting the rise of drug resistance at a much higher rate than those seen in humans. And if the bacteria gains a foothold in the UK (and there’s not much we can do to spot it apart from screenings) our drugs won’t be able to destroy it. So even such a low number of cases is worrying.

Where’s it coming from?

The Guardian reports that last year, out of 100 samples of pork from UK supermarkets, nine were found to contain MRSA. One of these was sourced from an Irish farm, and the others from pigs in Denmark. The findings marked the first confirmed occurrence of the superbug in the UK.

Image credits Tim Geers / Flickr.

While it’s impossible to determine if the meat tested now comes from UK or imported pigs, it does show that the bacteria is present in UK farms. Imports are likely the original source of the infection, The Guardian adds. At least one Danish farm has been found to be a regular supplier of importer pigs to the UK even if their pigs were contaminated with MRSA in 2014, the BIJ reported. The company, Breeding Centre Rønshauge A/S, refused to say how many pigs it had exported to the UK and whether they could have been contaminated. But official export figures show that the company supplied 41 pigs to the UK in July this year, 65 in 2013 and 16 in 2012. The UK government does not screen for the infection in imported animals, citing a low risk of serious illness.

“It is extremely worrying to find LA [livestock-associated]-MRSA in British-produced pork,” said Emma Rose, from the Alliance to Save Our Antibiotics.

“Scientists are now warning that the extensive MRSA reservoir in animals could ultimately lead to a pandemic spread in the human population. LA-MRSA is able to cause serious and potentially fatal infections in humans, and as the bacteria is resistant to antibiotics, it is extremely difficult to treat. What’s more, even more dangerous variations are emerging as the superbug evolves.”

The Department for Environment, Food and Rural Affairs (Defra) said that LA-MRSA “is not the same as MRSA strains that can cause healthcare-associated infections” if the meat isn’t properly cooked, and the risk to people is “low”. Defra and the National Pig Association recommend that all pigs imported to Britain be screened for the bacteria.

“The government is reviewing options for surveillance, which will be proportionate to the very low health risk posed by livestock-associated MRSA.”

When animals are imported, they’re screened for multiple diseases, but the one for CC398 is voluntary. So there’s no way to know how many infected pigs there are in UK right now. There have been two confirmed cases, one in Northern Ireland and one in eastern England, but without any systematic tests carried out in farms, all we’re left with are extremely rough estimations. The publication says that this and other health concerns related to UK meat come down to pressure towards factory farms producing the cheapest possible meat.