Current iterations of the hygiene hypothesis suggest an adaptive role for helminth parasites
in shaping the proper maturation of the immune system. However, aspects of this
hypothesis are based on assumptions that may not fully account for realities about human
helminth infections. Such realities include evidence of causal associations between helminth
infections and asthma or inflammatory bowel disease as well as the fact that helminth
infections remain widespread in the United States, especially among populations at
greatest risk for inflammatory and autoimmune diseases.