An intervention to reduce occupational exposure to methicillin-resistant Staphylococcus aureus in communal showers for pork production workers

Methicillin-resistant Staphylococcus aureus (MRSA) associated with livestock contact has recently been documented in the United States. Multi locus sequence type 398 (ST398) is the only livestock-associated (LA-MRSA) strain that has been found in U.S. pork production workers to date. Pigs are known to be a source of ST398, and the role of environment in LA-MRSA transmission is generally unclear. However, we have documented the presence of ST398 in communal showers in pork production facilities. In order to investigate this further, we recruited two conventional swine production systems to participate in an intervention study evaluating MRSA prevention guidelines derived from a literature review of practices used to prevent MRSA transmission in athletic facilities. We swabbed ten locations each in five different showers (at two finisher locations and one sow farm location), focusing on areas with which workers would commonly be in contact. After the initial samples were collected, pork producers were asked to implement our MRSA prevention guidelines. Approximately four weeks later, investigators returned to repeat the shower sampling. The same investigator took both the before and after intervention samples, and the same locations were used for sampling in each shower. Overall, results from the intervention were mixed. Although the general trend showed reduction in MRSA prevalence post-intervention, in two showers we observed sampling sites which were negative pre-intervention become positive post-intervention. We recommend that this intervention be repeated on a larger scale, and that implementation of the intervention is directly observed by investigators in future studies.