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

Inclusion 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.

Exclusion Criteria:

* 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.