Is cryptococcal meningoencephalitis in the tropics a distinct entity? A retrospective study from Thailand.

Twenty-four consecutive patients with central nervous system cryptococcosis (C.C.) have been studied retrospectively. In contrary to many reports from America or Europe only two patients suffered from an underlying immunocompromising disease. All patients were treated uniformly by amphotericin B and 5-fluorocytosin. They were monitored closely and dose-adjustment was done according to laboratory data. None of the patients died. Sixteen were available for a six-month post-treatment follow-up: seven had various degrees of neurological long-term sequelae whereas nine had no complaints and neurological examination was without abnormal findings. Our series is compared with others both from tropical and non-tropical countries. In accordance with all but one larger series from the tropics the relatively good prognosis and extremely rare occurrence of C.C. in immunocompromised persons is noted. Since different varieties of Cryptococcus neoformans have been shown to exist in different climate zones, this might be one of the possible explanations for the lack of preceding immune-compromising conditions in persons suffering from C.C. in the tropics and the benign course of disease.