Simultaneous infections with Cryptococcus neoformans and Histoplasma capsulatum are rare and typically occur in immunocompromised individuals, particularly AIDS patients. Because both of those fungi can spur the development of latent infections, it is generally unknown which organism was first present. The diagnosis of one fungus can hide the diagnosis of the other, leading to underdiagnoses and poor prognosis. We report a case of C. neoformans and H. capsulatum co-infection. We also performed a systematic review of the literature. Our patient, a 69-year-old HIV-negative man, presented with a 9-month history of a productive cough, dyspnea and wheezing. His history showed chronic obstructive pulmonary disease and type II diabetes mellitus (DM). Pulmonary lesions of unidentified etiology were noted. Cryptococcal involvement of the central nervous system was confirmed, and C. neoformans and H. capsulatum were also isolated from blood cultures. In the literature, we found ten cases of simultaneous histoplasmosis and cryptococcosis. Including our patient, all of the cases were located in North America and Latin America, except for two, one Indian and one African diagnosed in France. AIDS was the main predisposing factor, followed by DM and age >60 years. Several diagnostic methods were employed. A blood culture and bronchoalveolar lavage (BAL) culture resulted in the growth of C. neoformans in most of the cases. H. capsulatum was more often detected in BAL and bone marrow cultures. Although co-infection by these pathogens is severe, it can be cured if it is diagnosed and treated early. We emphasized the importance of clinical suspicion and differential diagnosis of systemic mycoses.
Keywords: Co-infection; Cryptococcosis; Cryptococcus neoformans; Histoplasma capsulatum; Histoplasmosis; Simultaneous.