Candida spp. is frequently isolated in critically ill patients with peritonitis. Guidelines recommend empirical antifungal therapy in high-risk cases, but the clinical significance of Candida spp. isolation in peritoneal fluid and the benefit of early antifungal therapy remain uncertain.

We conducted a retrospective multicenter cohort study including all consecutive adults admitted with peritonitis to the ICUs of four hospitals in Western France between 2020 and 2022. Risk factors for Candida spp. isolation in peritoneal fluid were assessed using multivariate logistic regression. Outcomes were compared according to Candida spp. isolation in peritoneal fluid and, among affected patients, according to early antifungal therapy. Survival up to day-90 after peritonitis onset were compared using Inverse Probability Treatment-weighted Cox proportional hazards models.

Among 378 patients, Candida spp. was isolated in 81 (21.4%). Independent risk factors included antimicrobial therapy within the last 3 months (adjusted OR 2.15, 95% CI 1.20–3.81; p = 0.009), malnutrition (adjusted OR 1.84, 95% CI 1.10–3.14; p = 0.022), upper gastrointestinal origin (adjusted OR 2.04, 95% CI 1.20–3.44; p = 0.008) and diffuse peritonitis (adjusted OR 1.75, 95% CI 1.01–3.13; p = 0.049). Candida spp. isolation in peritoneal fluid was not associated with 90-day mortality (weighted HR 1.00, 95% CI 0.62–1.59; p = 0.991) and clinical courses were similar between groups. Among patients with Candida spp. in peritoneal fluid isolation, early antifungal therapy was not associated with 90-day mortality (weighted HR 1.37, 95% CI 0.58–3.22; p = 0.470) or clinical outcomes.

In ICU patients with peritonitis, Candida spp. isolation in peritoneal fluid was not associated with 90-day mortality, and early antifungal therapy did not improve 90-day survival among patient with isolated Candida spp. in peritoneal fluid.