The incidence of inflammatory bowel disease (IBD) in the developing world is low compared to the developed world. One possible explanation is the "hygiene hypothesis" which suggests that overly sterile environments negatively impact immune development which predispose to immune mediated diseases such as IBD. The protective effect of helminth infection on the development of IBD has been postulated to be a consequence of their immunomodulatory effects, mediated by upregulation of the Th2 response and downregulation ofThl. Ascaris lumbricoides and Trichuris trichiura infections are endemic to the Western Cape, South Africa where the incidence of IBD has been historically low. As socioeconomic conditions improve, the incidence of IBD is rising. We postulate that helminth infection is protective in the development of IBD in the Western Cape, South Africa. The specific aims of our study are to identify the cytokine/chemokine profile of individuals with active Ascaris lumbricoides and Trichuris trichiura infection, to develop a seromarker signature for Ascaris lumbricoides and Trichuris trichiura infection, and to compare the cytokine/chemokine profiles and seromarker levels of individuals with and without IBD. We expect that the IBD cases will have a lower incidence of immunoseropositivity to Ascaris lumbricoides and Trichuris trichiura and a lower Th2 response compared to controls. We also expect that a higher proportion ofIBD cases will come from urban areas, live in more hygienic living standards, and have a lower personal history of helminth infection compared to non-IBD controls.