Fungal central nervous system infections

Infections of the central nervous system (CNS) are amongst the most severe of all fungal infections. Cryptococcus neoformans is the commonest cause of adult meningitis in many countries with high HIV prevalence. C gattii is usually seen in the tropics in apparently immunocompetent patients. Meningitis is also caused by Candida in premature babies, and by the dimorphic fungi in endemic areas. CNS infections with Aspergillus, the mucormycetes, and less common moulds usually present as intracranial mass lesions in immunocompromised hosts. Early suspicion, prompt imaging, and appropriate samples for culture, histology, and antigen and molecular tests are all critical for early diagnosis. Organism-specific antifungal therapy relies largely on liposomal amphotericin B and voriconazole, with therapeutic drug monitoring for the latter. Amphotericin B plus flucytosine is recommended for cryptococcal meningitis. Management of underlying conditions is also critical. Targeted prophylaxis in highest risk groups and pre-emptive therapy for HIV-associated cryptococcosis hold promise for prevention and improved outcome.