EFSA publishes results of the first survey on MRSA in pigs in the EU

The European Food Safety Authority (EFSA) has published the first EU-wide survey on MRSA (Methicillin-resistant Staphylococcus aureus) in breeding pigs. The results indicate that MRSA, a bacterium resistant to many antibiotics, is commonly detected in holdings with breeding pigs in some EU Member States. The survey provides estimates of its occurrence and makes recommendations for further monitoring and investigation of the causes and implications of MRSA findings in pig holdings in the EU.

The survey was carried out in 24 Member States[1], 17 of which found some type of MRSA in their holdings with breeding pigs and 7 none at all. On average, different types of MRSA were found in 1 out of 4 holdings with breeding pigs across the EU, but the survey also says that figures vary greatly between Member States. MRSA ST398 was the most reported type of MRSA among the holdings with breeding pigs in the EU; some Member States also reported other types, but their prevalence was much lower[2].

MRSA is a major concern for public health and its various types are recognised as an important cause of hospital-acquired (or nosocomial) infections in humans. The specific type MRSA ST398 has been identified in some domestic animals and is considered an occupational health risk for farmers, veterinarians and their families, who may become exposed to it through direct or indirect contact with these animals. In an opinion published earlier this year, EFSA’s Biological Hazards (BIOHAZ) Panel assessed the public health significance of MRSA in animals and food[3] and concluded that the MRSA ST398[4] strain is less likely to contribute to the spread of MRSA in hospitals than other types carried by humans. The Panel also said that there is currently no evidence that MRSA ST398 can be transmitted to humans by eating or handling contaminated food.

In the survey published today, EFSA recommends monitoring of pigs and other food producing animals for MRSA. It also says further research should be carried out, so that the reasons for differences in the prevalence of MRSA in the various Member States can be identified and used to propose options on possible control measures.

Notes to editors

The Staphylococcus aureus is a bacterium that can be persistently or intermittently carried by healthy humans and is a very common cause of minor skin infections that usually do not require treatment. In patients in hospitals, Staphylococcus aureus is a common cause of hospital-acquired infections. Its variant Methicillin-Resistant Staphylococcus aureus (MRSA) emerged in the 1970s and is now often found in hospitals in many European Member States. MRSA is resistant to many commonly used antibiotics. In recent years, clones of MRSA have evolved outside the hospitals, causing infections among people who have no connection with hospitals. Most recently MRSA has also been detected in several farm animal species.

EFSA’s Zoonoses Unit monitors and analyses the situation on zoonoses, zoonotic agents, antimicrobial resistance, microbiological contaminants and food-borne outbreaks across Europe. The Unit is supported by a Task Force on Zoonoses Data Collection consisting of a pan-European network of national representatives of Member States, other reporting countries, as well as World Health Organisation (WHO) and World organisation for animal health (OIE). They gather each year data in their respective countries.

EFSA’s BIOHAZ Panel provides scientific advice on biological hazards in relation to food safety and food-borne diseases. This covers food-borne zoonoses (animal diseases transmissible to humans), Transmissible spongiform Encephalopathies (BSE/TSEs), food microbiology, food hygiene and associated waste management issues. The Panel’s risk assessment work helps to provide a sound foundation for European policies and legislation and supports risk managers in taking effective and timely decisions.

EFSA’s previous work on MRSA:

[1] The sampling took place during 2008. Dust samples were taken in the environment of pigs in a total of 5,073 holdings from 24 EU Member States and two non-Member States. The pooled sample of each holding was tested for the presence of the various MRSA strains.
[2] Only six Member States and one non-Member State reported MRSA non-ST398 in the holdings with breeding pigs. The prevalence of MRSA non-ST398 in holdings with breeding pigs across the participating Member States was substantially lower than the prevalence of MRSA and MRSA ST398.
[3] EFSA’s BIOHAZ Panel opinion on the “ Assessment of the Public Health significance of meticillin resistant Staphylococcus aureus (MRSA) in animals and foods ” of March 2009
[4] In its opinion the BIOHAZ Panel refers to CC398 which corresponds to MRSA ST398.

Saites ar zinātni

Analysis of the baseline survey on MRSA in breeding pigs in the EU, 2008 - Part A