Cryptococcal Infection of the Ventriculoperitoneal Shunt in an Immunocompetent Patient

BACKGROUND Ventriculoperitoneal shunting is an effective treatment for hydrocephalus. Ventriculoperitoneal shunt (VPS) infection is a common complication. Cryptococcus neoformans as an implicated organism is rare. In this report, we describe a patient with cryptococcal VPS infection. CASE REPORT A 52-year-old male with normal pressure hydrocephalus, status post implantation of VPS one year prior to the presentation; who was admitted with a fever, lethargy and confusion for three days. He was treated empirically with intravenous cefepime and vancomycin for VPS infection. The CSF analysis from both the lumbar puncture and the VPS was significant for a low white blood count, low glucose and high protein. Other work-up including India ink and cryptococcal antigen was unrevealing. He remained febrile despite antibiotic treatment for 5 days. The CSF from the shunt was sent for analysis again and it demonstrated similar results from the prior study, but the culture was now positive for Cryptococcus neoformans. The patient was started on oral flucytosine and intravenous liposomal amphotericin B. The VPS was removed and an externalized ventricular catheter was placed. The patient showed rapid resolution of the symptoms. CONCLUSIONS To date, there was a total of nine reported cases of cryptococcal VPS infection upon review of the literature. Our presenting case and the literature review highlight the difficulties in making an accurate diagnosis of cryptococcal shunt infection. There were case reports of false negative cryptococcal antigen tests with culture proven cryptococcal meningitis. The CSF culture from the shunt remains a mainstay for identifying cryptococcal shunt infection. Cryptococcal shunt infections are rare and early diagnosis and treatment is essential for patient management which involves shunt replacement with concomitant administration of intravenous antifungal medication. High clinical suspicion is crucial and shunt culture preferably from the valve is recommended.