Entomophthoromycosis due to Conidiobolus

Abstract

Entomophthoromycosis due to Conidiobolus coronatus is a granulomatous infection characterized by lesions that originate in the inferior turbinate, spread through ostia and foramina to involve the facial and subcutaneous tissues and paranasal sinuses. The majority of the cases have been described from areas of tropical rainforest in West Africa, agricultural and outdoor workers (aged 20-60 years) being the ones most frequently affected. The fungus is common in soil and decaying vegetation. Infection probably occurs by implantation of the spores of the fungus in nasal mucosa. C. incongruus is a rare agent of the disease, so far known only from two cases with lesions involving the pericardium, mediastinum, lungs, liver, oesophagus and jejunum. C. coronatus is known to cause a clinically similar disease in horses, mules, a dolphin and a chimpanzee. A characteristic histological feature is the presence of thin-walled, broad, often septate hyphae or hyphal fragments with a thick eosinophilic sheath, frequently phagocytosed within giant cells. The fungus is known to produce in vitro several enzymes, e.g., elastase, esterase, collagenase and lipase, which have a possible role in pathogenicity. A concentrated brain heart infusion culture filtrate antigen is useful for immunodiagnosis. Several drugs e.g., potassium iodide, cotrimoxazole, amphotericin B, ketoconazole and itraconazole have been tried with varying success. Investigations on the immunology of disease and the role of proteases and lipases in the pathogenesis of infection is an important area of further research.

Unusual Fungal and Pseudofungal Infections of Humans

“…The predilection for host and anatomic site of infection is species specific: B. ranarum causes subcutaneous infection of the proximal limbs in children, whereas Conidiobolus spp. infection is localized to the facial area predominately in adults (14,31,78,96).…”

“…Both types of entomophthoromycosis are seen most commonly in Africa and to a lesser extent in India (16,31,62,78,96). Infection due to Basidiobolus spp.…”

“…has also been reported from the Middle East, Asia, and Europe (62, 78, 96), whereas that due to Conidiobolus spp. has been reported from Latin America as well (16,31). Cases of basidiobolomycosis and conidiobolomycosis in the United States are extremely rare and appear to be more acutely invasive than those seen more commonly in the tropics (25,40,53,91,97,98).…”

“…occur following inhalation of the fungal spores, which then invade the tissues of the nasal cavity, the paranasal sinuses and facial soft tissues. There is a 10:1 male/female ratio, and the disease is seen predominantly in young adults (31,78). Infection among children is rare.…”

Molecular Characterization of Ovine Zygomycosis in Central Western Brazil

“…4,12,16 Mycotic infection may occur through the inhalation of environmental spores that lodge in the nasal cavity or from minor trauma, such as an insect bite. 9 Virulence factors described for these pathogens during the infection are largely unknown; most studies involved insects. 8,24 Disease diagnosis is based on isolation of the agent and the presence of typical clinical and pathological findings, 19 however, mycological culture is slow and may be associated with false-negative test results.…”