A recent publication by scientists at Cambridge University has documented the increase in infection among hog herds with a methicillin-resistant strain of Staphylococcus aureus (MRSA). In 2008, less than five percent of Danish herds sampled carried the specific MRSA designated CC398. In 2018, the infection rate had increased to 90 percent.
The CC398 MRSA strain is zoonotic and poses a risk to public health. This specific strain is adapted to human hosts and has the ability to overcome an immune response.
An epidemiologic study in Denmark demonstrated that even following withdrawal of antibiotics, CC398 can persist in sequential placements of hogs, although other strains of potentially pathogenic bacteria have declined in prevalence and their spectrum of antibiotic resistance. This is attributed to strict control over administration of antibiotics of human health significance.