HIV-Associated Histoplasmosis

Abstract

Impaired immunity induced by HIV is one of the main causes of disseminated histoplasmosis in endemic areas, and thus from 1987 WHO and then the CDC classified this condition as an AIDS-defining illness. Host factors associated independently with histoplasmosis are low level of CD4 (<150 cell/mm3) and CD8 count, low nadir CD4, male gender, the absence of cART, the absence of systemic antifungals, and history of herpes simplex infection. Dissemination of an exogenously new acquired infection or reinfection and reactivation of a latent infection are both described in HIV-infected patients. Also, inflammatory reconstitution disease following cART initiation is possible. Acute pulmonary infection is rare, and only in HIV-infected patients with CD4 > 200 cell/mm3. In advanced disease, the most frequent manifestation is as disseminated histoplasmosis often acute and severe, with complications such as respiratory failure, circulatory shock, and disseminated intravascular coagulation. The subacute presentation is frequent, associated with moderate involvement of the reticuloendothelial system, with great variability of clinical manifestation. Guidelines for diagnosing and managing histoplasmosis among people living with HIV have been published from WHO, IDSA, NIH, but limited data was based on randomized clinical trials.