Sex-related differences in clinical characteristics, management, and outcomes of Enterococcus faecalis bloodstream infection

OBJECTIVES: To evaluate whether clinical characteristics and outcomes of patients with Enterococcus faecalis bloodstream infection (EF-BSI) differ by biological sex. METHODS: Quasi-experimental study conducted at two hospitals, comprising a retrospective phase (2017-2019) and a prospective intervention phase (2022-2024), including adults with a first episode of monomicrobial EF-BSI. Patients who died within 72 h or were receiving palliative care were excluded. A structured management bundle was implemented in the intervention phase. Clinical features, bundle adherence, and 90-day mortality were compared by sex. Cox regression was used to assess the association between sex and 90-day mortality. RESULTS: Among 250 patients, 77 (31%) were females and 173 (69%) males. Females were younger than males (median 63 [50-76] vs. 73 [63-80] years; p < 0.001). Cardiovascular disease was more frequent in males (30 [39%] vs. 94 [54%]; p = 0.025), whereas immunosuppressive therapy (29 [38%] vs. 35 [20%]; p = 0.004) and connective tissue disease (9 [12%] vs. 2 [1%]; p < 0.001) were more frequent in females. Persistent bacteraemia (2/57 [4%] vs. 30/139 [22%]; p = 0.002) and infective endocarditis (14 [18%] vs. 59 [34%]; p = 0.011) were more frequent in males. Females received fewer bundle measures (5 [3-6] vs. 5 [4-6]; p = 0.028), largely because echocardiography and colonoscopy were less frequently indicated. Ninety-day mortality was 22% (17) in females and 14% (25) in males (p = 0.136). Female sex was associated with higher 90-day mortality after adjustment (aHR 2.00, 95%CI 1.04-3.83). CONCLUSIONS: Further studies should explore the underlying causes of these differences and potential implications for individualized management.