Abstract:
To optimize diagnosis of histoplasmosis in tissue sections, 30 spleen specimens from mice, infected with Histoplasma capsulatum, were examined by H&E , Grocott stain, anti-bacille antibody immunostain, Fungiqual A fluorochrome stain, and a nested PCR assay. Results were compared with the tissue burden determined by quantitative culture. By applying logistic regression, the nested PCR assay was the most sensitive method, but not significantly more sensitive than the Grocott stain. The Grocott and fluorochrome stains did not differ significantly in detecting fungal elements. Both stains were significantly more sensitive than the H&E and the anti-bacille antibody immunostain, which did not differ significantly in detecting fungal elements. The PCR assay unambigously identified Histoplasma capsulatum in tissue sections.