Experimental Infection of Hookworm-naïve Adults With Dermally-applied Infectious Necator Americanus Hookworm Larvae

Eligibility Criteria

• * Males or females between 18 and 45 years, inclusive.
• * Good general health as determined by means of the screening procedure.
• * Available for the duration of the trial (6 months).
• * Willingness to participate in the study as evidenced by signing the informed consent document.
• * Pregnancy as determined by a positive urine human choriogonadotropin (hCG) (if female).
• * Participant unwilling to use reliable contraception methods while participating in the study (if female and not surgically sterile, abstinent or at least 2 years post-menopausal).
• * Currently lactating and breast-feeding (if female).
• * Evidence of clinically significant neurologic, cardiac, pulmonary, hepatic, rheumatologic, autoimmune, diabetes, or renal disease by history, physical examination, and/or laboratory studies.
• * Known or suspected immunodeficiency.
• * Laboratory evidence of liver disease (alanine aminotransferase \[ALT\] greater than 1.25-times the upper reference limit).
• * Laboratory evidence of renal disease (serum creatinine greater than 1.25-times the upper reference limit, or more than trace protein or blood on urine dipstick testing).
• * Laboratory evidence of hematologic disease (hemoglobin \<11.5 g/dl \[females\] or \<12.5 g/dl \[males\]; absolute leukocyte count \<3.6 or \>10.7 x 103/mm3; absolute neutrophil count \[ANC\] \<1.7 x 103/mm3; absolute lymphocyte count \<0.7 x 103/mm3; or platelet count \<140 x 103/mm3).
• * History of iron deficiency anemia.
• * History of hypoalbuminemia.
• * Laboratory evidence of a coagulopathy (PTT or PT INR greater than 1.1-times the upper reference limit).
• * Serum glucose (random) greater than 1.2-times the upper reference limit.
• * Other condition that in the opinion of the investigator would jeopardize the safety or rights of a volunteer participating in the trial or would render the subject unable to comply with the protocol.
• * Volunteer has had medical, occupational, or family problems as a result of alcohol or illicit drug use during the past 12 months.
• * History of a severe allergic reaction or anaphylaxis.
• * Severe asthma as defined by the need for daily use of inhalers or emergency clinic visit or hospitalization within 6 months of the volunteer's expected Day 0 of the study.
• * Positive ELISA for hepatitis B surface antigen (HBsAg).
• * Positive confirmatory test for HIV infection.
• * Positive confirmatory test for hepatitis C virus (HCV) infection.
• * Use of corticosteroids (excluding topical or nasal) or immunosuppressive drugs within 30 days of the volunteer's expected Day 0 of this study or planned use during the study.
• * Receipt of a live vaccine within 4 weeks or a killed vaccine within 2 weeks prior to the volunteer's expected Day 0 of the study.
• * Receipt of blood products within the past 6 months.
• * Known allergy to amphotericin B or gentamicin.
• * History of previous infection with hookworm or residence for more than 6 months in a hookworm-endemic area.