Trends and outcomes in community-onset and hospital-onset among hospitals in the United States from 2015 to 2020.

Background: We investigated trends in (staph) bacteremia incidence stratified by methicillin susceptibility (methicillin-susceptible [MSSA] vs. methicillin-resistant [MRSA]) and onset designation (community-onset [CO] vs. hospital-onset [HO]).

Methods: We evaluated the microbiological data among adult patients who were admitted to 267 acute-care hospitals during October 1, 2015, to February 28, 2020. Using a subset of data from 41 acute-care hospitals, we conducted a retrospective cohort study to assess patient demographics, characteristics, mortality, length of stay, and costs. We also conducted a case-control study between those with and without staph bacteremia.

Results: The incidence of MSSA bacteremia significantly increased from 2.43 per 1,000 admissions to 2.87 per 1,000 admissions (estimate=0.0047, -value=.0006). The incidence of MRSA significantly increased from 2.11 per 1,000 admissions to 2.42 per 1,000 admissions (estimate=0.0126, -value <.0001). While the incidence of CO MSSA and CO MRSA demonstrated a significant increase (p=0.0023, and p < 0.0001), the incidence of HO MSSA and HO MRSA did not significantly change (p=0.2795 and p < 0.4464). Compared to those without staph bacteremia, mortality, length of stay, and total cost were significantly higher in those with staph bacteremia, regardless of methicillin susceptibility or onset designation.

Conclusion: The increasing incidence of CO MSSA and MRSA bacteremia might suggest the necessity for dedicated infection control measures and interventions for community members colonized with or at risk of acquiring .