Endemic mycoses in AIDS: a clinical review

Abstract

Histoplasmosis and coccidioidomycosis are serious opportunistic infections in patients with AIDS who reside in areas of endemicity of the United States and Central and South America. Blastomycosis, although less common, also must be recognized as an opportunistic infection in patients with AIDS. Prompt diagnosis requires knowledge of the clinical syndromes and diagnostic tests as well as a high index of suspicion. Histoplasmosis and blastomycosis respond well to antifungal treatment, but relapse is common without chronic suppressive therapy. Improvements in treatment are needed in coccidioidomycosis. Research is needed to identify preventive strategies for patients at risk. These strategies may include use of prophylactic antifungal therapy or vaccination.

Rapid PCR-Based Diagnosis of Disseminated Histoplasmosis in an AIDS Patient

“…Patients complain of dyspnea, cough, fever and weight loss. Common findings include lymphadenopathy, hepatomegaly, splenomegaly and CD4+ cell counts below 200/µl [1]. The clinical signs as well as the findings on chest radiographs are easily confused with other opportunistic infections such as PCP, miliary tuberculosis or mycoses due to other thermally dimorphic fungi.…”

“…It is unclear why we were unable to detect specific DNA in the blood sample; clearly, PCR cannot replace culture but it adds to the diagnostic armamentarium. The PCR assay might be comparable to the antigen assay, which is characterized by high sensitivity and good specificity but which has limited utility because it is not commercially available [1,2].…”

“…Disseminated histoplasmosis is a result of primary infection or due to reactivation of a latent infection. It is recognized as an AIDS-defining illness in up to 5% of HIV-infected patients in endemic areas [1]. Histoplasmosis is rarely diagnosed outside endemic areas, usually in patients with a travel history to or originating from countries known to be endemic for the disease.…”

Histoplasmosis: Epidemiology in Latin America

“…In the immunocompetent population, it is most common in persons involved in removal of soil, visiting caves, cleaning old houses, or felling trees [1•, 2•, 5]. Currently, the most significant settings for severe disseminated and often fatal conditions comprise patients with underlying cell-mediated immunologic defects, including those with HIV infection (patients with CD4 counts <150-200/mm 3 ) [6,7], transplant recipients, and individuals receiving tumor necrosis factor (TNF)-α inhibitors [2•]. Immunocompromised persons with histoplasmosis have a higher mortality rate than those who are not immunosuppressed [6,7].…”

“…Currently, the most significant settings for severe disseminated and often fatal conditions comprise patients with underlying cell-mediated immunologic defects, including those with HIV infection (patients with CD4 counts <150-200/mm 3 ) [6,7], transplant recipients, and individuals receiving tumor necrosis factor (TNF)-α inhibitors [2•]. Immunocompromised persons with histoplasmosis have a higher mortality rate than those who are not immunosuppressed [6,7]. Despite the substantial number of patients in this region with histoplasmosis, epidemiologic and clinical data are sparse and patchy, and prevention, diagnosis, and treatment of the disease remain difficult [4••].…”