Disseminated Cryptococcus neoformans infection is a serious opportunistic infection that occurs in patients with untreated AIDS . Although cryptococcal infection begins in the lungs, meningitis is the most frequently encountered manifestation of cryptococcosis among those with advanced immunosuppression. However, the infection is more properly characterized as "meningoencephalitis" rather than meningitis since the brain parenchyma is almost always involved on histologic examination [2,3].
The clinical manifestations and diagnosis of C. neoformans meningoencephalitis in AIDS patients will be reviewed here. Treatment and monitoring of AIDS patients with cryptococcal meningoencephalitis is found elsewhere. The microbiology, clinical manifestations, and treatment of this infection in other patient populations, such as transplant patients, are discussed elsewhere. C. gattii infection is also presented separately. (See "Treatment of Cryptococcus neoformans meningoencephalitis in HIV-infected patients" and "Clinical management and monitoring during antifungal therapy of the HIV-infected patient with cryptococcal meningoencephalitis" and "Microbiology and epidemiology of Cryptococcus neoformans infection" and "Clinical manifestations and diagnosis of Cryptococcus neoformans meningoencephalitis in HIV seronegative patients" and "Treatment of Cryptococcus neoformans meningoencephalitis and disseminated infection in HIV seronegative patients" and "Cryptococcus neoformans infection outside the central nervous system" and "Cryptococcus gattii infection: Microbiology, epidemiology, and pathogenesis" and "Cryptococcus gattii infection: Clinical features and diagnosis" and "Cryptococcus gattii infection: Treatment".)
Globally, it is estimated that approximately 957,900 cases of cryptococcal meningoencephalitis occur each year, resulting in more than 600,000 deaths [4,5]. The region with the highest number of estimated cases in 2006 was sub-Saharan Africa (720,000 cases; range, 144,000 to 1.3 million), followed by South and Southeast Asia (120,000 cases; range, 24,000 to 216,000) . A low CD4 cell count is the main predictor of risk of cryptococcal meningoencephalitis; the vast majority of cases occur among AIDS patients with a CD4 cell count <100 cells/mm3.
The incidence of cryptococcal meningoencephalitis has declined in patients who have access to antiretroviral therapy (ART) . However, cryptococcal disease remains a leading cause of mortality in the developing world where access to ART is limited .
Symptoms — Symptoms of cryptococcal meningoencephalitis typically begin indolently over a period of one to two weeks. The most common symptoms are fever, malaise, and headache . Stiff neck, photophobia, and vomiting are seen in one-fourth to one-third of patients. Patients rarely present with coma and fulminant death in days.