Microsporidiosis
What is microsporidiosis?
Microsporidiosis is a disease that is due to infection with
microscopic organisms called microsporidia. These are small simple
single-celled (protozoan) parasites that form spores. These parasites
must live within other cells and are found in the intestine, liver,
kidney, cornea, brain, nerves, and muscles. These spores spread to
other cells or are eliminated in the stool or urine.
Microsporidia have not been studied very thoroughly as agents of
disease, partly because they are quite small. They are difficult to
diagnose without the aid of an electron microscope, a piece of
equipment that is not in a routine diagnostic microbiology
laboratory. A number of animals, including insects, birds, and
mammals,
can serve as reservoirs of infection for microsporidia.
How are microsporidia transmitted?
The microsporidia spores are released from the gastrointestinal
and urinary tracts of infected animals. The spores are then consumed
by people. Within the bowels, a spore unfolds a long, thin, coiled
tube that is used to penetrate a cell. Once within the cell, the
microsporidia develop and multiply.
What conditions does infection with microsporidia cause?
Although microsporidia can infect people with normal immune
systems, they typically do not develop symptoms. Symptoms of
microsporidiosis generally occur in people with immune deficiency.
Microsporidiosis is a cause of bowel, lung, kidney, brain, sinus and
eye disease in people with AIDS and other conditions that are caused
by immune deficiency.
Intestinal symptoms that are caused by microsporidia infection
include wasting, chronic diarrhea, and gallbladder disease. The
diarrheal stools are typically watery and are not accompanied by
blood in the stool or by fever.
Lung symptoms include a cough and difficult, labored breathing. A
chest X-ray may show signs of inflammation, fluid, or cavities in the
lungs.
Infection with microsporidia can cause blood in the urine, kidney
failure, bladder inflammation, and bowel perforation. Microsporidia
can also spread throughout the body to cause inflammation in the
brain, pancreas, gallbladder, sinuses, and ears. Microsporidia have
even been seen in muscle tissue.
Two types of microsporidial eye infection occur in patients with
AIDS. The first type is infection of the cornea following an eye
injury, which may result in corneal perforation and blindness. (This
condition is rarely seen in persons with normal immune systems.) The
second type involves inflammation of the cornea and the conjunctiva
of the eye (keratoconjunctivitis) in patients with AIDS.
Next: How is microsporidiosis diagnosed? »
 |
 |
From the Doctors at MedicineNet.com  |
|
Last Editorial Review: 4/24/2002
Specialty RSS
Ask the Experts
