EFSA evaluates factors contributing to MRSA in pigs

EFSA has published an evaluation of factors that may contribute to the spread of MRSA (Methicillin-resistant Staphylococcus aureus) in pig holdings in the European Union, following on from the publication of the first EU-wide survey on the occurrence The fact or frequency of something (e.g. a disease or deficiency in a population) happening. of this bacterium in pigs[1].

Most MRSA infections are transmitted through direct or indirect human-to-human contact. People can also be exposed to MRSA through contact with infected animals; this is in particular the case for farmers, veterinarians and their families. There is currently no evidence that MRSA can be transmitted to humans through the consumption or handling of contaminated food[2].

EFSA’s survey shows that bigger pig holdings are more likely to be contaminated with MRSA. This was found to be the case for both breeding and production holdings[3]. As an example, the study says that a breeding holding with more than 400 breeding pigs is twice more likely to be contaminated with MRSA compared to one with less than 100 breeding pigs.

In addition, EFSA’s analysis highlights that animal movement may play a role in the contamination of breeding pigs’ holdings with MRSA: both through the trade of breeding pigs between Member States and the movements of pigs between breeding and production holdings within the same Member State. The data also show a positive correlation A statistical term to describe the relationship between two variables (e.g. calcium intake and bone growth). between the number of cases found in breeding holdings and those found in production holdings. This finding suggests that MRSA is transmitted through the movement of animals between the two types of holdings.

EFSA recommends that more information is gathered at national level on those factors that put pig holdings at risk of infection with MRSA and on the measures that can prevent its spread.

• Analysis of the baseline survey on the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in holdings with breeding pigs, in the EU, 2008 - Part B: factors associated with MRSA contamination of holdings

Notes to editors:

EFSA provides scientific advice on risks to animal and human health from the possible emergence, spread and transfer of antimicrobial resistance The ability of microbes to grow in the presence of substances specifically designed to kill them; for example, some human infections are now resistant to antibiotics, raising concerns about their widespread use. through the food chain. Antimicrobial resistance is an issue that concerns various sectors of the food chain and EFSA follows an integrated approach in assessing this risk, involving various Panels and Units, as well as cooperation with other European agencies such as the European Centre for Disease Prevention and Control (ECDC) and the European Medicines Agency (EMA).

EFSA’s Zoonoses Data Collection Unit monitors and analyses data on zoonotic A term given to diseases and infections that can be transmitted between animals and humans. bacteria and parasites across the EU and co-ordinates baseline survey reports on food-borne zoonotic agents found in foods and in animals. These surveys are used by risk assessors such as EFSA’s Biological Hazards (BIOHAZ) Panel to provide risk estimates and also by risk managers to help set reduction targets.