Adiaspiromycosis

Adiaspiromycosis is an emerging and neglected zoonotic fungal disease caused by the genus Emmonsia. The genus Emmonsia has undergone many taxonomic modifications, and the species causing adiaspiromycosis are currently renamed as Emergomyces crescens and Blastomyces parva. It has the potential to infect both immunocompetent and immunocompromised individuals. The fungus resides in the soil, serving as its reservoir, and is known to infect a wide range of mammals, thus posing a threat to zoonotic transmission worldwide. These species cause infection in more than 100 mammalian species. Humans are the accidental hosts; they acquire the infection by the inhalation of conidia. Since Emmonsia/Emergomyces is a saprobic soil fungus, infection is more common in individuals with occupational exposure to dust. The formation of ‘adispores/adiaconidia’, subsequently leading to granuloma formation, is the characteristic pathology. The infection in humans is mostly self-limiting, with a few symptomatic cases. The patient usually presents with a pulmonary nodule. Histopathological examination is the most used diagnostic method, but molecular techniques have recently gained importance. These molecular techniques not only aid in determining the taxonomic classification of Emmonsia but also reveal molecular differences between Emmonsia and Chrysosporium. Additionally, studies on different Emmonsia species have helped to clarify the distinct status of Emmonsia parva, Emmonsia crescens and Emmonsia pasteuriana. Due to the rarity of the disease, there are currently no established guidelines for the management of patients. However, the preferred treatment approaches include antifungal medications, corticosteroids, supportive care or a combination of the first two, with surgical excision considered when feasible.