The usefulness of blood culture in diagnosing HIV-related systemic mycoses: evaluation of a manual lysis centrifugation method

Abstract

The results of 5034 blood cultures, implementing a lysis-centrifugation method with saponin, are summarized in this paper. Three hundred and twenty-two blood samples (6.3%) obtained from a pool of human immunodeficiency virus (HIV)-positive patients yielded fungi. Cryptococcus neoformans was isolated in 199 samples (3.95%), Histoplasma capsulatum in 95 (1.89%). Candida parapsilosis in 12 (0.23%), C. albicans in 7 (0.13%), C. tropicalis in 2, C. krusei in 1, C. guillermondii in 1, and Prototheca wickerhamii in 4 (0.07%). Blood cultures were positive for C. neoformans in 76.23% of patients having a diagnosis of cryptococcosis and in 89.65% of those who had histoplasmosis. The blood culture was the first means of confirming the diagnosis in 23.8% of the patients with cryptococcosis and in 54% with histoplasmosis. In the four patients in whom P. wickerhamii was isolated, a diagnosis of disseminated protothecosis was not achieved by other findings. Catheter infections were responsible for the majority of recovered Candida spp.