Strongyloidiasis is infection with the roundworm Strongyloides stercoralis (S. stercoralis).
Causes, incidence, and risk factors
S. stercoralis is a roundworm that is fairly common in warm, moist areas. Rarely, it can be found as far north as Canada.
People catch the infection when they come in contact with soil contaminated with the worms.
The tiny worm is barely visible to the naked eye. Young roundworms can move through a person's skin and into the bloodstream to the lungs and airways. As the worms grow older, they bury themselves in the walls of the intestines. Later, they produce eggs in the intestines. Areas where the worms go through the skin may become red and painful.
This infection is uncommon in the United States. Most cases seen in North America are brought by travelers who have visited or lived in South America or Africa.
Most of the time, there are no symptoms.
If there are symptoms, they may include:
Signs and tests
The following tests may be done:
The goal of treatment is to eliminate the worms with anti-worm medications such as ivermectin.
In some cases, such as in those who will be taking immunosuppressive drugs, people with no symptoms are treated.
Full recovery with eradication of parasites is expected with adequate treatment. Sometimes treatment needs to be repeated.
Infections that are widespread often have a poor outcome, especially in people with weakened immune systems.
Calling your health care provider
Call for an appointment with your health care provider if you have symptoms of strongyloidiasis.
Good personal hygiene can reduce the risk of strongyloidiasis. Adequate public health services and sanitary facilities provide good control of infection.
ReferencesKazura JW. Nematode infections. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 378.
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School, Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.