Controlled Human Infection Study of Orally Administered Trichuris Trichiura Eggs in Naïve Adults

Inclusion Criteria:

1. Males or females between 18 and 45 years, inclusive.

2. Good general health as determined by means of the screening procedures.

3. Available for the duration of the trial (approximately 7.5 months).

4. Willingness to participate in the study as evidenced by signing the informed consentdocument.

Exclusion Criteria:

1. Pregnancy as determined by a positive urine human choriogonadotropin (hCG) (iffemale).

2. Participant unwilling to use reliable contraception methods while participating inthe study (if female of reproductive potential who is engaging in sexual activitythat could lead to pregnancy); being of reproductive potential is defined as notbeing surgically sterile, abstinent from intercourse with a male partner, in amonogamous relationship with a vasectomized partner, at least 2 yearspost-menopausal, or determined otherwise by medical evaluation to be sterile.

3. Currently lactating and breast-feeding (if female).

4. Evidence of clinically significant neurologic, cardiac, pulmonary, hepatic,rheumatologic, autoimmune, diabetes, or renal disease by history, physicalexamination, and/or laboratory studies.

5. Has a diagnosis of schizophrenia, bipolar disease or other major psychiatriccondition that would make compliance with study visits/procedures difficult (e.g.,subject with psychoses or history of suicide attempt or gesture in the 3 yearsbefore study entry, ongoing risk for suicide).

6. Known or suspected immunodeficiency or immunosuppression as a result of anunderlying illness or treatment.

7. Laboratory evidence of liver disease (alanine aminotransferase [ALT] greater than 1.25-times the upper reference limit).

8. Laboratory evidence of renal disease (serum creatinine greater than 1.25-times theupper reference limit).

9. Laboratory evidence of hematologic disease (hemoglobin <11.1 g/dl [females] or <12.5g/dl [males]; absolute leukocyte count <3.4 or >11.0 x 103/mm3; absolute eosinophilcount >0.6 x 103/mm3 or platelet count <125 x 103/mm3).

10. Positive fecal occult blood test.

11. Infection with a pathogenic intestinal helminth as determined by stool examinationfor ova and parasites.

12. History of iron deficiency anemia or laboratory evidence of iron deficiency (serumferritin concentration below the lower reference limit).

13. Other condition that in the opinion of the investigator would jeopardize the safetyor rights of a volunteer participating in the trial or would render the participantunable to comply with the protocol.

14. Volunteer has had medical, occupational, or family problems as a result of alcoholor illicit drug use during the past 24 months.

15. Positive ELISA for hepatitis B surface antigen (HBsAg).

16. Positive confirmatory test for HIV infection.

17. Positive confirmatory test for hepatitis C virus (HCV) infection.

18. Using or intends to continue using oral or parenteral corticosteroids, high-doseinhaled corticosteroids (>800 μg/day of beclomethasone dipropionate or equivalent)or other immunosuppressive or cytotoxic drugs within 30 days of the volunteer'sexpected enrollment in this study or planned use during the study.

19. Known allergy to albendazole.

20. History of previous infection with T. trichiura or continuous residence for morethan 6 months in a T. trichiura-endemic area.