Microsporidiosis is a disease caused by infection with microscopic organisms called microsporidia. Microsporidia are eukaryotic parasites that must live within other host cells in which they can produce infective spores.
These spores cause microsporidiosis, a disease which is primarily seen in individuals infected with human immunodeficiency virus (HIV).
Microsporidiosis can cause infection of the intestine, lung, kidney, brain, sinuses, muscles, and eyes.
Although there are over 1,200 species of microsporidia, the most prevalent pathogens (disease-causing agents) in humans include Enterocytozoon bieneusi, Encephalitozoon cuniculi, and Encephalitozoon intestinalis.
How are microsporidia transmitted?
Microsporidia spores are released from the stool and urine of infected animals. A number of animals, including insects, birds, and mammals, can serve as reservoirs of infection for microsporidia.
These spores are then consumed or inhaled by humans.
Once within a cell, the microsporidia develop and multiply, producing more spores. The infective spores are then released when the cell expands and bursts.
Symptoms of Microsporidiosis
Symptoms of microsporidiosis vary depending on
Which species causes the infection
Which organs are affected
How well a person’s immune system is working
People with a normal immune system typically have no symptoms, but microsporidiosis can cause chronic diarrhea in people with AIDS.
Other microsporidiosis symptoms may include abdominal pain, jaundice, fever, weight loss, a persistent cough, pain in the side (flank), muscle aches, headache, and eye inflammation with redness.
Vision may be blurred. If infection is severe, blindness may result.
Diagnosis of Microsporidiosis
Examination of a sample of the affected tissue under a microscope
To diagnose microsporidiosis, doctors examine a sample of the affected tissue under a microscope, usually using special techniques to make the protozoa more visible.
Samples of stool, urine, blood, sputum, cerebrospinal fluid (taken by Tests for Brain, Spinal Cord, and Nerve Disorders : Spinal Tap spinal tap), cornea (taken by scraping), or other tissue (taken by biopsy) may be needed.
Special tests are also used to identify the parasite’s genetic material (DNA) in the sample.
Treatment of Microsporidiosis
For persistent diarrhea, albendazole (a drug usually used to treat worm infections—an antihelminthic drug)
If the immune system is normal, microsporidiosis treatment is rarely needed.
For persistent diarrhea, albendazole, taken by mouth, may help control symptoms if the species causing the infection is susceptible to it. However, the drug does not eliminate the infection.
If people have AIDS, it is also very important that the HIV infection is treated as effectively as possible. Such treatment can strengthen the weakened immune system and thus usually helps control the diarrhea.
Eye drops containing albendazole and fumagillin may relieve eye symptoms. If they do not, surgery to repair the cornea (keratoplasty) may be required.
How is microsporidiosis prevented?
For patients with immune-system deficiency, frequent hand washing and limiting exposure to animals suspected of being infected with microsporidia is recommended.