Increased incidence of disseminated histoplasmosis following highly active antiretroviral therapy initiation.

To determine whether the initiation of highly active antiretroviral therapy (HAART) had any influence on the incidence of disseminated histoplasmosis, a retrospective cohort study was performed on 1551 patients followed for up to 12 years. After controlling for CD4 counts, age, and sex, patients taking HAART for 2 months or less were more likely to develop disseminated histoplasmosis than untreated patients (respectively, hazard ratio, 3.7 [95% confidence interval, 1.57-8.7]; P = 0.003). In contrast, after 6 months of HAART, treated patients were less likely to develop disseminated histoplasmosis than untreated patients (hazard ratio, 0.6 [95% confidence interval, 0.37-0.98], P = 0.04). This increased incidence suggests that the initiation of HAART and the subsequent immune reconstitution may reveal undiagnosed latent disseminated histoplasmosis.