I refer you to
REGULATION (EC) No 852/2004 on the hygiene of foodstuffs,2004 Chapter X paragraph 2
“No person suffering from, or being a carrier of a disease likely to be transmitted through food or afflicted, for example, with infected wounds, skin infections, sores or diarrhoea is to be permitted to handle food or enter any food-handling area in any capacity if there is any likelihood of direct or indirect contamination…”.
So unless someone has been diagnosed as having an MRSA infection or carrying the bacterium, exclusion, from a LEGAL perspective, would seem to be unnecessary. Reading the FSA’s Food Handlers: Fitness to Work Regulatory Guidance and Best Practice Advice 2008 one comes to the same conclusion.
From a RISK perspective the CDC, USA offer the following reassurance on the MRSA as a food borne infection.
“Most MRSA cases are skin and soft tissue non-life-threatening infections that are spread between people in the community through skin-to-skin contact….. to date, there have not been any documented cases of people getting MRSA from eating food that contains MRSA….”
(http://www.cdc.gov/drugresistance/organisms/mrsa-and-food-products.html. Page last updated: June 27, 2011)
And in the Royal college of Physicians 2008 publication Infected food handlers: Occupational aspects of management. A national guideline it is concluded that “poor hygiene practices, in particular hand washing, by food handlers at mass catering events, were identified as a cause of outbreaks of Staphylococcus aureus…” and that in their study “there was no evidence that food handlers with skin conditions affecting hands, arms or face, boils, styes, cut or septic fingers, or discharges from eyes, ears, gums or mouth, were associated with infecting food”