First case of MRSA in UK pig
The risk of MRSA to humans remains very low, according to BVA.
For the first time in the UK, a piglet in Northern Ireland has been infected with livestock-associated MRSA (LA-MRSA).
According to a letter published in the Veterinary Record, the post-weaning piglet was one of five tested at the Omagh disease surveillance laboratory of the Agri-Food and Biosciences Institute (AFBI) in May this year.
It is the first known case of LA-MRSA in UK pigs. In a joint statement, the BVA and Pig Veterinary Society (PVS) said the MRSA risk to humans remains very low.
The piglet had a history of pneumonia and wasting and there had been 10 per cent piglet mortality on the farm involved over a period of two or three months.
AFBI said the discovery of LA-MRSA in this piglet is considered to be incidental. It is thought the main disease factor in the case was the piglet's infection with the European strain porcine reproductive and respiratory syndrome virus (PRRSV).
Following the announcement, the Alliance to Save our Antibiotics has urged the government to carry out a full survey of the UK pig industry to find out how widespread the superbug is. The group is also calling for immediate restrictions on the farm use of antibiotics deemed “critically important” to human medicine.
BVA and PVS said: “The Alliance to Save our Antibiotics seems to suggest that vets use large amounts of this critically important group of antibiotics. However, the group of antibiotics considered critically important is available for individual animal treatment only and not for mass medication through feed or water.”
Both organisations have issued advice to their members that these groups of drugs should only be used where evidence suggests this is absolutely necessary.
According to current scientific evidence, antibiotic resistance in human medicine is primarily due to antibiotic use in people, not animals. However, BVA and PVS said “any isolation of resistant organisms in food producing animals is of concern.”
However, the organisations added: “It is worth noting that the LA-MRSA found in the pig in Northern Ireland is genetically different from the MRSA strains causing healthcare-associated human infections and it does not spread so readily between humans.”
LA-MRSA was first confirmed in the Netherlands in 2003, when it was linked to pigs, pig farmers and subsequently cattle.
In countries where there is a high prevalence of the superbug, such as the Netherlands, Germany and Denmark, research suggests that people working with livestock are more likely to become infected with MRSA than those with no direct contact with animals.
MRSA is not considered to be a food borne disease and the Food Standards Agency says cooking meat properly should render the risk to consumers negligible.
RCVS Knowledge has welcomed Professor Peter Cockcroft as editor-in-chief for Veterinary Evidence. 
