The superbug meticillin resistant Staphylococcus aureus (MRSA) is able to infect food but eating or handling tainted produce does not present an increased health hazard to humans, a new report has said.
However, the study, compiled jointly by European Food Safety Authority (EFSA), the European Centre for Disease Control and Prevention (ECDC) and the European Medicines Agency (EMEA), found that people who work closely with MRSA-infected animals are at risk of catching the bacteria. Farmers, veterinarians and their families face the greatest threat, they concluded.
The research also highlighted the hazards from overuse of antimicrobial medicines for animals and recommended exploring the development of alternative treatments.
The research will confirm claims made by a number of bodies, including the UK’s Soil Association, which previously claimed the bacteria was present in animals and able to jump across species. The European health agencies acknowledged that it carried out the research because of “increasing concern about the public health impact of MRSA” from food producing and companion animals.
The report found that in food producing species a new MRSA clone called CC398 had emerged – and is most often carried without symptoms by pigs, veal calves and broiler chickens. This strain can in rare cases trigger serious skin and soft tissue infections, pneumonia and blood poisoning in humans.
Food can be tainted by MRSA - including the CC398 strain. But while the report found that “eating and handling contaminated food is a potential vehicle for transmission” but that there is currently “no evidence for increased risk of human colonization or infection” following contact with MRSA-contaminated produce.
An EFSA statement concluded: "While food may be contaminated by MRSA there is currently no evidence that eating or handling contaminated food can lead to an increased health risk for humans."
This finding has been welcomed by the Confederation of the Food and Drink Industries of the EU (CIAA) as “reassuring for consumers”. But the body said it was “important to continue to monitor this issue and carry out further research”.
The EFSA report concluded that the most effective control measures for MRSA will be at farm level, since animal movement and contact between live animals and humans are likely to be important factors in the transmission of the bug.
Antimicrobial alternatives needed
MRSA is known to be resistant to antimicrobial veterinary medicines and the European health agencies cautioned that “prudent use of antimicrobials in animals” should be key. “Any measures to be taken should consider all antimicrobials with the aim to eliminate unnecessary use or replace use with other strategies," they recommended.
Intensive farming accused
The UK’s Soil Association has also welcomed the study and said it agreed with its overall conclusion. But the organization raised concerns over the role of intensive farming practices of animals used in food production in the emergence of MRSA.
“It is because of the intensive conditions in which they are raised that animals are so frequently sick and require frequent antibiotic treatment,” said Soil Association policy advisor Richard Young. He added that in the UK, the two most intensively reared species, pigs and poultry, account for 96% of farm antibiotic consumption, with similar patterns occurring abroad.
“It is no coincidence that MRSA emerged first in European pigs and is now becoming established in European poultry. Any serious attempt to reduce agricultural antibiotic consumption must therefore involve moving to less intensive and more free-range rearing,” said Young.
He also called on the UK Government to publish results of its own research on incidents of MRSA in pigs, as other EU member states have. Young also criticised UK authorities for “refusing to test British poultry, even though studies in other European countries have already found that MRSA is present in poultry”.