Abstract
Background
Methicillin-sensible S. aureus bloodstream infections (MSSA BSIs) have high morbidity and mortality, especially in end stage renal disease (ESRD) and in patients on dialysis. While oxacillin is the first-line treatment, cefazolin could be a better-tolerated alternative. This study compares their efficacy and safety in this population.
Methods
We conducted a retrospective, single-center observational study including all adult patients with MSSA BSI and ESRD or dialysis who received definitive therapy with either oxacillin or cefazolin between 01/2021 and 12/2023 at AOU of Modena. The primary outcome was a composite of mortality and recurrence at 30 and 90 days. Secondary outcomes included individual components of the primary outcome, persistent bacteremia for ≥5 days, intensive care unit (ICU) admission and adverse drug reactions.
Results
Sixty patients met the inclusion criteria, 51 patients were treated with oxacillin and 9 patients with cefazolin. Detailed clinical characteristics are reported in Table 1. At 30 days 14 patients died (23.3%) (OXA 13[25.49%] versus CEF 1[11.11%] P = 0.347), while 20 died (33.3%) at 90 days (OXA 17[33%] versus CEF 3[33%] P = 0.509). Only 2 recurrences were observed at 90 days in cefazolin group (3.33%) (P = 0.0001). Persistent positive BSI were observed in 29 patients (58%) in the oxacillin group and 6 patients (67.67%) in the cefazolin group (P = 0.626). ICU admission was required for 5 oxacillin-treated patients (10.64%) and 1 cefazolin-treated patient (12.50%) (P = 0.876). Two patients on oxacillin experienced adverse-drug reaction (3.92%). Cefazolin was associated with lower length of hospitalization (OXA 23 days [IQR:16–33] versus CEF 14 [12–16] P = 0.022). Univariate, multivariate analysis and Kaplan-Meier find that being treated with cefazolin was associated with a shorter length of hospitalisation (OR 0.642, [CI 0.008–0.501] P = 0.009). Persistent bacteremia was associated to longer hospitalization, (OR 7.820 [1.450–42.17] P = 0.017).
Conclusions
Cefazolin showed comparable efficacy to oxacillin in MSSA BSI with better tolerability in patients with ESRD or dialysis, making it a potential alternative. Larger studies are needed to confirm these findings.
Table 1.
Study population baseline characteristics and Descriptive analysis according to CEF/OXA therapy