Operating room PathTrac analysis of current intraoperative Staphylococcus aureus transmission dynamics

Background: Operating room (OR) reservoir Staphylococcus aureus isolates have been linked to 50% of surgical site infections. We aimed to assess S aureus transmission dynamics in today's ORs to further guide health care–associated infection prevention. Methods: Forty OR case-pairs were randomly selected for observation in a 5-month prospective cohort study. Case-pair S aureus transmission dynamics were mapped using OR PathTrac. Results: S aureus pathogens were isolated from ≥1 OR reservoirs in 45.7% (37 of 81) of surgical cases, and epidemiologically related transmission events were confirmed in 22.5% (9 of 40) of case-pairs. Patient skin sites and provider hands provided comparable risk of OR S aureus exposure (19 of 481 patient vs 35 of 1,173 provider hands, relative risk [RR], 1.32; 95% confidence interval [CI], 0.77-2.29; P = .32). Environmental contamination at case 2 start was higher than at case 1 start (case 2 start 32 of 152 sites with >20 colony-forming units vs case 1 start 7 of 163 sites with >20 colony-forming units; RR, 4.90; 95% CI, 2.23-10.77; P < .0001). The stopcock contamination rate was not significantly different than our prior study in 2008 (19 of 164 2008 vs 8 of 77 2018; RR, 1.12; 95% CI, 0.51-2.43; P = .78). All epidemiologically related transmission events involved the between-case mode of transmission and phenotype H. Conclusions: Current OR S aureus exposure threats reliably include patient skin sites and provider hands. Perioperative S aureus preventive measures should extend from patient decolonization to include improved hand decontamination efforts.