Places of residence of participants with antibody levels suggesting prior exposure to Cryptosporidium spp. Cp17 and Cp23 (n = 538) (A), Giardia duodenalis VSP3 (n = 111) (B), and Cryptosporidium spp. Cp17 and Cp23 and Giardia duodenalis VSP3 (combined) (n = 38) (C), Mississippi, USA. All serologic assays were performed using MAGPIX multiplex recombinant antigen beads (ThermoFisher, https://www.thermofisher.com) on convenience serum samples collected at the University of Mississippi Medical Center (Jackson, MS, USA) during October 28, 2017–March 29, 2018. Only those samples confirmed by a subsequent S. stercoralis crude L3 larval antigen (CrAg) ELISA are included.