Entomophthoramycosis (also known as entomophthoromycosis) is the disease caused by fungi belonging to the order of Entomophthorales. Due to a change in high-level fungal taxonomy, the class Zygomycetes was renamed Glomeromycetes. Glomeromycetes include 2 orders of fungi, namely Mucorales and Entomophthorales.

Basidiobolomycosis and conidiobolomycosis are the 2 clinical entities classified as entomophthoramycosis:

• Basidiobolus ranarum is responsible for basidiobolomycosis in human infection.
• Conidiobolomycosis is an infection caused by Conidiobolus coronatus or Conidiobolus incongruus.

Both clinical entities are regarded as a rare chronic non-angioinvasive mycotic disease affecting otherwise healthy individuals in tropical areas of Africa, South America, and Asia. There are 3 recognized clinical forms: rhinofacial, subcutaneous, and visceral/disseminated.

This summary will focus on visceral/disseminated entomophthoramycosis. The other 2, rhinofacial and subcutaneous, are discussed separately: see Rhinofacial conidiobolomycosis and Cutaneous basidiobolomycosis, respectively.  

Visceral entomophthoramycosis is exceedingly uncommon and most often results from infection with B. ranarum, a fungus that can be found in soil and decaying vegetation. The source of infection is possibly accidental ingestion of soil or soil-contaminated foods, or hand-to-mouth contamination. Due to its rarity, risk factors are not well understood. The organs most commonly involved are the stomach and colon, which can lead to a misdiagnosis of inflammatory bowel disease.

There was a reported case series (7 patients) of gastrointestinal basidiobolomycosis in Arizona. All patients were born in the United States and were not obviously immunosuppressed. No mortality was observed in this case series.

A fatal case of severe disseminated basidiobolomycosis involving brain, lung, stomach, kidney, pancreas, and spleen was diagnosed postmortem and reported in Italy in an apparently immunocompetent host. The mortality of disseminated entomophthoramycosis is reportedly low (2%), and it usually occurs in patients with immunosuppression from diabetes mellitus or steroid use.

Related topic: Mucormycosis