Central nervous system infections in solid organ transplant recipients: Results from the Swiss Transplant Cohort Study

Objectives: To describe the epidemiology and clinical presentation of central nervous system (CNS) infections in solid organ transplant (SOT) recipients in the current era of transplantation. Methods: Patients from the Swiss Transplant Cohort Study (STCS) transplanted between 2008 and 2018 were included with a median follow-up of 3.8 years. Epidemiological, microbiological, and clinical data were extracted from the STCS database and patients' medical records. We calculated incidence rates and 90-day survival of transplant recipients with CNS infection. Results: Among 4762 patients, 42 episodes of CNS infection in 41 (0.8%) SOT recipients were identified, with an overall incidence rate of 2.06 per 1000 patient-years. Incidence of CNS infections was similar across all types of transplantations. Time to CNS infection onset ranged from 0.6 to 97 months after transplant. There were 22/42 (52.4%) cases of viral infections, 11/42 (26.2%) of fungal infections, 5/42 (11.9%) of bacterial infections and 4/42 (9.5%) of probable viral/bacterial etiology. Clinical presentation was meningitis/encephalitis in 25 cases (59.5%) and brain-space occupying lesions in 17 cases (40.5%). Twenty-three cases (60.5%) were considered opportunistic infections. Diagnosis were achieved mainly by brain biopsy/necropsy (15/42, 36%) or by cerebrospinal fluid analysis (20/42, 48%). Up to 40% of cases (17/42) had concurrent extra-neurological disease localizations. Overall, 90-day mortality rate was 29.0% (73.0% for fungal, 14.0% for viral and 11.0% for bacterial and probable infections, p<0.0001). Conclusions: CNS infections were rare in the STCS, with viral meningoencephalitis being the most common disease. Fungal infections were associated with a high mortality.