Propionibacterium Acnes: A Difficult-to-Diagnose Ventriculoperitoneal Shunt Infection. Case Report

Ventriculoperitoneal (VP) shunt infections are a fairly common complication in both the early and late postoperative periods. Sometimes diagnosis is difficult despite the fact that infection is often accompanied by clinical symptoms. Furthermore, pathogenic bacteria can be detected in the cerebrospinal fluid. We describe a case of chronic VP shunt infection in a 24-year-old female patient who was operated on for posterior fossa pilocytic astrocytoma and needed a VP shunt. The infection revealed itself 5 years after shunt implantation with nonspecific symptoms, and it took approximately 2 years to make a correct diagnosis. Meanwhile, the patient's condition became critical. The infection was caused by Propionibacterium acnes, which is capable of forming biofilms on implants, and which is difficult to identify due to the peculiarity of its cultivation. When the bacterium was identified, the shunt was replaced and antimicrobial therapy was performed, after which the patient's condition improved dramatically and she got back to her normal life. This case shows how difficult the diagnosis of VP shunt infection can be and what clinical significance it can have for the patient.