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.

Condition	Treatment or Intervention
HIV Infection Nematode Infection Strongyloidiasis	Drug: Strongyloides Skin Test Antigen

Further Study Details: 

Expected Total Enrollment:  650

This study is directed to patients with known or suspected Strongyloides stercoralis infection because it is a relatively common parasitic infection, even in the United States; it is difficult to diagnose, and efficacy of treatment is difficult to evaluate. Some infected individuals can develop serious, even fatal, disease under certain conditions of immunosuppression. We have developed an immediate hypersensitivity skin test which appears useful for more rapid and simplified diagnosis of infection with the parasite. A cDNA library from the infective form of the parasite has been prepared, and several clones identified from which we will try to select recombinant gene products that can be used as diagnostic antigens. An interesting association of infection with the strongyloides parasite in certain patients also infected with the retrovirus HTLV-1 has been discovered, in which activation of Th1 cytokines and output of interferon gamma results in lowering of serum IgE. This can lead to greater likelihood of severe disease in some patients or incomplete response to treatment.

Genders Eligible for Study:  Both

Accepts Healthy Volunteers

Criteria

INCLUSION CRITERIA:
Age of 5 to 80 years and of either sex.
Parents or guardian for children under 18 years must be able to understand and sign informed consent.
Presence of known or suspected infection with Stronglyloides stercoralis, such as significant peripheral blood eosinophilia (greater than 1000 eosinophils/mm(3)) for which no other cause is apparent.
EXCLUSION CRITERIA:
None, other than those conditions which fail to meet the inclusion criteria listed above.
Pregnancy is not a criteria for exclusion.

Maryland
      National Institute of Allergy and Infectious Diseases (NIAID), 9000 Rockville Pike,  Bethesda,  Maryland,  20892,  United States; Recruiting

Study ID Numbers:  890174; 89-I-0174
Record last reviewed:  September 17, 2004
Last Updated:  November 23, 2004
Record first received:  November 3, 1999
ClinicalTrials.gov Identifier:  NCT00001245
Health Authority: United States: Federal Government
ClinicalTrials.gov processed this record on 2005-04-08