Relationship between livestock exposure and methicillin-resistant Staphylococcus aureus carriage in humans: A systematic review and dose-response meta-analysis.

Abstract

BACKGROUND\nAlthough previous studies have suggested an association between livestock exposure and the risk of methicillin-resistant Staphylococcus aureus (MRSA) carriage in humans, it remains unclear whether there is a dose-response relationship.\n\n\nOBJECTIVE\nThe aim of this study was to evaluate the relationship between livestock exposure and MRSA carriage.\n\n\nMETHODS\nPooled risk estimates were calculated using fixed-effect or random-effect models based on homogeneity analysis. The dose-response meta-analysis based on linear and non-linear regression was performed to explore the frequency-risk relationship between livestock exposure and MRSA carriage. Subgroup analyses were conducted to explore the sources of heterogeneity among eligible studies.\n\n\nRESULTS\nTwenty-five studies were included in this meta-analysis. Livestock exposure was significantly associated with the increased risk of MRSA carriage (OR=7.03, 95% CI 4.29-11.52), and similar positive associations were observed for pig (OR=11.41), poultry (OR=6.20), and cattle exposure (OR=5.66). As to studies on ordinal and continuous frequency of livestock exposure, we consistently observed a monotonically increasing frequency-risk relationship between livestock (or pig) exposure and MRSA carriage.\n\n\nCONCLUSIONS\nThis study found monotonically increasing frequency-risk relationships between livestock exposure and MRSA carriage, which provides evidence for the potential livestock-to-human transmission of MRSA.