| Research has identified antibiotic-resistant livestock-associated Staphylococcus aureus (LA-SA) in humans, suggesting that animal husbandry is contributing to the global spread of antibiotic resistance. However, the prevalence of antibiotic-resistant LA-SA organisms and the factors contributing to their spread are poorly understood. This review (1) summarizes the prevalence of antibiotic-resistant LA-SA in humans, hogs, and pork products and (2) identifies factors contributing to LA-SA spread. A systematic literature review identified 78 relevant studies. Together, these studies document high prevalence in farm hogs (pooled prevalence: 19%), farm workers (pooled prevalence: 32%), slaughterhouse hogs (pooled prevalence: 24%), and veterinarians (pooled prevalence: 20%). Major risk factors include amount of antibiotic used, frequency and duration of human contact with hogs, large herd sizes, summer season, location downwind from hog farms, and hog farm density. These findings may be useful for modeling antibiotic resistance transmission risks under different hog farming practices. |
