|
|
Zygomycosis
Zygomycosis is a disease of humans and animals caused by fungi belonging to the class Zygomycetes: Mucorales and Entomophthorales. The Mucorales cause mucormycosis and include the genera Rhizopus, Mucor, Rhizomucor, Mortierella, Absidia, and others. The >Entomophthorales include Basidiobolus and Conidiobolus species, and disease induced by these fungi is termed entomophthoromycosis. Rhizopus spp. are the most common cause. These funguses are found throughout the natural environment and are present in soil and decaying vegetation. Zygomycetes is not the name of particular fungus, but rather the name of a class of fungi. This is a blood vessel-invading infection produced which also sometimes referred to as mucormycosis, but the term zygomycosis is preferred.
Generally, the Mucorales cause invasive, disseminated (spread throughout the body) disease in humans and animals. The Entomophthorales tend to cause localized subcutaneous and nasal granulomas in humans and animals. The way of infection may be ingestion, inhalation, or wound contamination. The disease has been reported in dogs, cats, and horses. Animal infections, are reported in the United States, Australia and other parts of the world. Feline zygomycosis is a serious condition that should be considered when tracheobronchial masses are identified.
Signs
In dogs and cats, two forms of the infection are seen: Subcutaneous form which affects tissues beneath the skin and visceral form that affects internal organs. The subcutaneous form is characterized by solitary or multiple nodules, which are typically ulcerated, and draining. The visceral form can be fatal. Symptoms of abdominal zygomycosis vary and depend on the site and extent of involvement. Diarrhea and bloody stools are recorded. Cutaneous lesions of zygomycosis are characteristically hemorrhagic, ulcerated or necrotic plaques.
Diagnosis and Treatment
The diagnosis of zygomycosis is based on isolation of the pathogen from infected tissues and requires several laboratory tests and fungal cultures. If lungs and abdomen are involved, surgery is necessary to save the patient; the disease is often fatal when the heart is become invaded. Statins combined with amphotericin B have a therapeutic potential against fungal infections caused by Zygomycetes species.
Prognosis
Subcutaneous form is guarded. Visceral form is poor. In humans the disease is associated with the acidotic diabetics, malnourished children, and severely burned patients. It is also seen with leukemia, lymphoma, AIDS, and use of immunosuppressive therapy such as corticosteroids. The rhinocerebral form is the most frequent presentation overall and classically affects diabetics with ketoacidosis. Usually presents with facial and/or eye pain, and progressive signs of involvement of eye structures (muscles, nerves and vessels).
References
- Scott, Miller, Griffin. Small Animal Dermatology
- Greene CE. Infectious Diseases of the Dog and Cat
- Rippon JW. Medical Mycology
- Scott DW. Large Animal Dermatology
|
Related Diseases and Disorders
|