Incidence of Staphylococcus aureus Infections after Elective Surgeries in U.S. Hospitals.

BACKGROUND Although S. aureus is a leading cause of postsurgical infections, national estimates of these infections after elective surgeries based on microbiology data are limited. This study assessed cumulative 180-day postsurgical S. aureus incidence in real-world hospital settings. METHODS A retrospective study of adults (≥18 years) undergoing inpatient or hospital-based outpatient elective surgeries from 7/1/2010-6/30/2015 at hospitals (N=181) reporting microbiology results in the Premier Healthcare Database (PHD). Eighty-six surgical categories were identified from the National Healthcare Safety Network procedures. We classified positive S. aureus cultures using a hierarchy (bloodstream [BSI], surgical site [SSI], and all other types [urinary tract, respiratory, other/unknown site]) and calculated incidence (number of infections divided by the number of elective surgery discharges). We estimated national infection case volumes by multiplying incidence by national inpatient elective surgical discharge estimates using the entire PHD and weights based on hospital characteristics. RESULTS Following 884,803 inpatient elective surgical discharges, 180-day S. aureus infection incidence was 1.35% (0.30% BSI, 0.74% SSI no BSI, 0.32% all other types only). Among 1,116,994 hospital-based outpatient elective surgical discharges, 180-day S. aureus incidence was 1.19% (0.25% BSI, 0.75% SSI no BSI, 0.19% all other types only). Methicillin-resistance was observed in approximately 45% of the S. aureus infections. We estimated 55,764 S. aureus post-surgical infections occurred annually in the US following 4.2 million elective inpatient surgical discharges. CONCLUSIONS The high burden of S. aureus infections after both inpatient and outpatient elective surgeries highlight the continued need for surveillance and novel infection prevention efforts.