Entomophthoramycosis: a neglected tropical mycosis

The term 'entomophthoramycosis' classically refers to infections caused by members of the order Entomophthorales. A new subphylum, Entomophthoramycota, has been created to include Basidiobolomycetes, Neozygitomycetes and Entomophthoramycetes. Basidiobolomycetes encompass Basidiobolus spp., while the Entomophthoramycetes include Conidiobolus spp. Conidiobolus spp. characteristically cause rhinofacial entomophthoramycosis in apparently immunocompetent hosts. Conidiobolus spp. may also cause disseminated infection in immunocompromised patients. Basidiobolus spp. more typically cause subcutaneous entomophthoramycosis of the limbs, buttocks, back and thorax in immunocompetent patients. While once considered to be rare, there is an increasing number of reported cases of gastrointestinal infection caused by Basidiobolus spp. worldwide in countries such as United States, Thailand, Australia, Iran, Egypt and Saudi Arabia. These cases have clinical presentations similar to those of inflammatory bowel diseases, particularly Crohn's disease. Retroperitoneal, pulmonary, nasal and disseminated basidiobolomycosis have also been reported. Histology of entomophthoramycosis may reveal the Splendore-Hoeppli phenomenon. Culture of infected tissue remains the definitive method of laboratory diagnosis. However, molecular methods with specific DNA probes and panfungal primers, as well as real time PCR, are increasingly used to detect and identify these organisms in tissue. Treatment largely consists of therapy with antifungal triazoles. Surgery plays a selective role in the management of entomophthoramycosis, depending upon location, organism and extent of the infection.