Study of Patients With Known or Suspected Infection With Strongyloides Stercoralis

This study will explore faster and easier ways to detect infection with the intestinal parasite Strongyloides stercoralis and learn more about the conditions under which it causes serious disease. Ordinarily, the Strongyloides helminth (type of intestinal worm) causes only few, if any, symptoms, but in people with weakened immunity it may be very serious, and even deadly.

People between 5 and 80 years of age with known or suspected S. stercoralis infection, or infection with another helminth, such as filariasis, that might cause a cross-reaction with S. stercoralis may be eligible for this study.

Participants found to be infected with S. stercoralis will be treated with ivermectin, thiabendazole, or albendazole. In addition, they will undergo the following tests and procedures:

• Blood tests and stool samples: Samples will be collected before and after treatment to check general health status and immune function, and to look for parasites in stool. Up to 50 milliliters (10 teaspoons) of blood will be drawn in adults and up to 25 ml (5 teaspoons) in children.
• Skin tests: A test similar to those used for tuberculosis and allergies will be conducted to determine if there is sensitization to products of the parasite. Such a test might be used as a rapid method to diagnose the infection. About three drops of several different antigens (proteins) are injected into the skin of the arm. After 15 to 20 minutes, the area is checked to see if a red spot has formed and, if so, the spot is measured.