Histoplasmosis diagnosis using a polymerase chain reaction method. Application on human samples in French Guiana, South America

Untreated histoplasmosis is life threatening, especially in immunosuppressed patients. In French Guiana, South America, it is one of the most common opportunistic infections in AIDS patients. Twenty-one cases of disseminated histoplasmosis were diagnosed in 2004 in the mycology laboratory of Cayenne hospital. Culture samples for histoplasmosis diagnosis is simple, sensitive, and specific, but it is a lengthy process. Management of the disease is then dangerously delayed. In this work, we tested a polymerase chain reaction (PCR) method on 40 samples from patients with suspected disseminated histoplasmosis. The recently described Hcp100 nested PCR method was used to detect Histoplasma capsulatum DNA in these samples. All of the positive cultures for H. capsulatum were also positive with PCR method. Tested on other fungi or negative culture, it also showed high specificity. Furthermore, it allows treating patients more rapidly. Culture remains necessary, but histoplasmosis PCR offers great prospects, on a clinical point of view.