Treatment of Strongyloides Infection

Patients will be randomly assigned to receive 2 single doses of ivermectin at 200 µg/kg 2 weeks apart versus ivermectin at 200 µg/kg for 2 consecutive days. Patients will be randomized 50-50 to the study groups using the date of birth and a random number table. All patients will be interviewed to obtain the medical history during the initial evaluation. Patients will be asked about demographic data on a questionnaire written in English and Spanish. Physical exams, baseline blood cell counts, serum chemistries, HTLV-1(human T-cell lymphotrophic virus) serology, an IgE (immunoglobulin E), a stool sample for O \&P, and a pregnancy test will be performed as routine care all patients currently receive in our clinic.Procedures: Strongyloides serology will be performed in the parasitology laboratory of Jacobi Hospital with an in-house ELISA that uses a 31-kDA(kilodalton) recombinant protein antigen (termed NIE) derived from L3 stage of S. stercoralis and purified from E. coli BL21 containing pET30b plasmid. Once the in-house serology is performed serum will be banked, so it can be available to run in paired with samples taken during follow up visits. Blood samples will be also collected and sent to the Laboratory of Parasitic Diseases (LPD) at the NIAID- National Institutes of Health (NIH) to perform other serological techniques including the Luciferase Immunoprecipitation Systems Assay (LIPS) based on NIE and the recombinant antigen S. stercoralis immunoreactive antigen (SsIR). In addition, stools will be collected from all patients and will be fixated in SAF(sodium acetate, acetic acid and formalin), to check for Strongyloides stercoralis larvae. If possible, fresh stool will be obtained to check for larvae using the Baermann technique and an aliquot will be frozen and sent to the NIH for DNA extraction and PCR(polymerase chain reaction as).