Steven Doerr, MD, is a U.S. board-certified Emergency Medicine Physician. Dr. Doerr received his undergraduate degree in Spanish from the University of Colorado at Boulder. He graduated with his Medical Degree from the University Of Colorado Health Sciences Center in Denver, Colorado in 1998 and completed his residency training in Emergency Medicine from Denver Health Medical Center in Denver, Colorado in 2002, where he also served as Chief Resident.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
What is microsporidiosis? What causes the disease?
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.
What symptoms does microsporidiosis cause?
Although microsporidiosis can occur in people with normal immune systems, it is very uncommon. The symptoms of microsporidiosis primarily occur in people with immune-system deficiency, such as HIV-infected individuals and organ-transplant recipients. Microsporidiosis can cause intestinal, lung, kidney, brain, sinus, muscle, or eye disease.
Intestinal symptoms that are caused by microsporidia infection include chronic diarrhea, wasting, malabsorption, and gallbladder disease. In patients with AIDS, the chronic diarrhea may be extremely debilitating and carries a significant mortality risk. The majority of cases of intestinal microsporidiosis in AIDS patients are caused by
Enterocytozoon bieneusi.
Lung symptoms may include a cough and difficult, labored breathing. A chest X-ray may show signs of inflammation, fluid, or cavities in the lungs.
Microsporidiosis can cause infection in the urinary tract, kidney failure, bladder inflammation, and bowel perforation. Microsporidia can also spread throughout the body to cause inflammation in the brain, pancreas, sinuses, and muscle tissue.
Eye infection with microsporidia can cause inflammation of the cornea and conjunctiva (keratoconjunctivitis). Symptoms of ocular microsporidiosis may include eye pain, eye redness, or blurry vision.
Urinary tract infection (UTI) is an infection of the kidney, ureter, bladder, and/or urethra. Not
everyone with a UTI has symptoms. Common symptoms include a frequent urge to
urinate and a painful, burning when urinating.
Kidney failure can occur from an acute event or a chronic condition or disease. Prerenal kidney failure is caused by blood loss, dehydration, medication. Some of the renal causes of kidney failure are from sepsis, medications, rhabdomyolysis, multiple myeloma, and acute glomerulonephritis. Post renal causes of kidney failure include bladder obstruction, prostate problems, tumors, or kidney stones. Treatment options included diet, medications, or dialysis.
Diarrhea is a change is the frequency and looseness of bowel movements. Cramping, abdominal pain, and the sensation of rectal urgency are all symptoms of diarrhea. Absorbents and anti-motility medications are used to treat diarrhea.
PCR (polymerase chain reaction) is a method to analyze a short sequence of
DNA (or RNA) even in samples
containing only minute quantities of DNA or RNA. PCR is used to reproduce
(amplify) selected sections of DNA or RNA. Previously, amplification of DNA involved cloning the segments of interest into vectors for
expression in bacteria, and took
weeks. But now, with PCR done in test tubes, it takes only a few hours. PCR is
highly efficient so that untold numbers of copies can be made of the DNA.
Moreover, PCR uses the same molecules that nature uses
for copying DNA:
Two "primers", short single-stranded DNA sequences that are synthesized to
correspond to the beginning and ending of the DNA stretch to be copied;
An enzyme called polymerase that moves along the segment of DNA, reading
its code and assembling a copy; and
A pile of DNA building blocks that the polymerase needs t...