The discovery on UK shelves of pork contaminated with a livestock strain of MRSA prompts calls to curb misuse of antibiotics in intensive farming
Pork sold by several leading British supermarkets has been found to be contaminated with a strain of the superbug MRSA that is linked to the overuse of powerful antibiotics on factory farms, a Guardian investigation has revealed.
Livestock-associated MRSA CC398, which originates in animals, has been found in pork products sold in Sainsbury’s, Asda, the Co-operative and Tesco. Of the 100 packets of pork chops, bacon and gammon tested by the Guardian, nine – eight Danish and one Irish – were found to have been infected with CC398.
CC398 in meat, which poses little risk to the British public, can be transmitted by touching infected meat products or coming into contact with contaminated livestock or people, although it can be killed through cooking.
Many people carry the bacteria without any signs of illness, but some have developed skin complaints, and the bug can cause life-threatening infections, including pneumonia and blood poisoning. Experts warn that the superbug has emerged as a result of antibiotic use in intensive farming and there is evidence that the UK could be at risk of a wider health crisis unless the issue is tackled by the authorities.
What is the superbug LA-MRSA CC398 and why is it spreading on farms?
The superbug CC398 is a variant of the more commonly known MRSA found in hospitals and is endemic in pig farms in some European countries, particularly Denmark, Europe’s biggest pork producer and a key exporter to the UK. The Guardian tested 74 Danish pork products and 25 British, and one from Ireland.
CC398 is linked to intensive farms, where the density of pigs crowded together becomes a flashpoint for disease, and farmers become reliant on antibiotics to keep animals healthy and alive. This has led to the emergence of CC398, which is resistant to antibiotics.
Two thirds of Denmark’s pig farms are currently infected with CC398, where it is spreading rapidly: 648 people were infected with CC398 in 2013; in 2014, 1,271 people contracted the bug. Of those infected two people died as a result of the infection, and many suffered serious blood poisoning.
None of the British pork tested by the Guardian was infected with CC398, but a similar study carried out by the Alliance to Save Antibiotics, a campaign group which includes the Soil Association, did identify the superbug in pork from British farms. In findings due to be published on Thursday, the Alliance identified the bug in a pork sausage and in a packet of pork mince purchased in the UK. Fifty-two samples of pork from supermarkets in Bristol, Cambridge, London, Northumberland and Surrey were tested by the University of Cambridge on behalf of the Alliance. The findings confirm that CC398 has now spread from British farms into the domestic pork supply chain.
A leading microbiologist has warned Britain to see the situation in Denmark as a warning. “[It] is an epidemic [that’s] out of control in Denmark,” Professor Hans Jørn Kolmos, a microbiologist at the University of Southern Denmark told the Guardian. “[Britain] should be worried about it, you should look at our problems. We should have intervened seven years back when we saw the first cases. Don’t think that this is a problem that will solve itself just by closing your eyes,” he said.
A Guardian film made during the investigation into infected pork also reveals how CC398 has already crossed the species barrier in the UK. A little-reported study by the University of Edinburgh, published in 2014, found the bug in the umbilical cords of two newborn babies in Scotland.
The Scottish study is thought to be the first confirmation in the UK that the bug has travelled from livestock to humans in Britain, though researchers were not able to explain how the superbug spread and there is nothing to suggest the babies became ill as a result of coming into contact with CC398.