Histoplasmosis

Dimorphic fungus. Growth on media below 350C is characterized by a  white or brown, hairlike mycelium and gowth at 370C produces a creamy  white, textured colony. Distrinuted endemically except Australia. The fungus  grows abundantly in moist soil high in nitrogen. Histoplasmosis may be benign,  severe, acute or chronic and it can show pulmonary, systemic or cutaneous  lesions. Its primary location of growth is in the cytoplasm of phagocytes such  as macrophages. It appears as a spherical “fish eye” yeasts intracellularly in  macrophages and occasionally free in sputum and CSF.  

The phylogentic analysis of H. capsulatum revealed eight clades based on  geographical distribution and conserved genes (Kasuga et al., 2003). In India,  144 cases of H. capsulatum have been reported after 1954 from a period from  1994 to 2017 (Mahajan et al., 2017)