Omadacycline for peritoneal dialysis-associated peritonitis caused by Coxiella burnetii: a case report and literature review

IntroductionPeritoneal dialysis-associated peritonitis (PDAP) is a serious complication of peritoneal dialysis (PD), contributing significantly to hospitalization rates and mortality. In recent years, infections caused by uncommon pathogens such as Coxiella burnetii have increasingly been identified, posing significant challenges to managing PDAP.Case presentationWe report a 62-year-old male hospitalized for recurrent PDAP unresponsive to empirical antibiotics (meropenem, later meropenem/vancomycin). Metagenomic next-generation sequencing (mNGS) of peritoneal fluid identified C. burnetii. Intravenous omadacycline was initiated as part of a multi-agent regimen (100 mg daily after 200 mg loading dose). Within 48 h, hemodynamic stability was achieved, and inflammatory markers (procalcitonin, C-reactive protein, effluent white blood cell count) normalized progressively over the subsequent week. The patient recovered fully and was discharged, and remained relapse-free during 3 months of follow-up.ConclusionThis case highlights the critical importance of identifying pathogens in patients with PDAP. Despite significant confounders (concurrent broad-spectrum antibiotics, ICU support, and polymicrobial infection) that limit definitive attribution, the use of omadacycline was associated with clinical recovery and suggests a potential role as an alternative therapeutic option for Coxiella burnetii infection. Further studies are warranted to validate its efficacy.