The Hygiene Hypothesis and Its Inconvenient Truths about Helminth Infections

Abstract

Author SummaryCurrent 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.

Soil‐transmitted helminth infection and intestinal inflammation among the Shuar of Amazonian Ecuador

“…This is difficult because, while STHs may have some anti-inflammatory and immune-regulatory effects, they also have serious consequences for naturally infected individuals, including negative health-related outcomes, poor childhood growth, and poverty promotion (Briggs et al, 2016). This is difficult because, while STHs may have some anti-inflammatory and immune-regulatory effects, they also have serious consequences for naturally infected individuals, including negative health-related outcomes, poor childhood growth, and poverty promotion (Briggs et al, 2016).…”

“…Trichuris trichiura has more immediate localized effect that triggers a greater immune response because adult worms directly attach to the intestine and injure host tissue (Bethony et al, 2006;Briggs et al, 2016;Bundy, 1986;Bundy & Cooper, 1989;Geiger et al, 2002). If these species-specific relationships are valid, however, they may be related to how the parasites interact with and feed on their host.…”

The Global State of Helminth Control and Elimination in Children

“…9 These findings go against the commonly held, but erroneous, belief that somehow worms protect children from asthma or IBD. 12 Children with hookworm experience iron-deficiency and iron-deficiency anemia, in addition to intestinal protein losses. 3 Young adults are also at risk of significant morbidity secondary to helminths.…”

Atypical presentation of hepatic visceral larva migrans mimicking cancer and associated with ADAMTS13 deficiency–mediated thrombotic microangiopathy: A first report from Reunion Island

“…Thus, treatment of autoimmune diseases by helminth infections is being studied in clinical trials, even though there are immense conflicting data regarding the benefits versus harms of using live helminths [20,21]. However, some rare reports showed that, due to thus-far-unknown reasons, a helminth infection conversely can trigger or boost an autoimmune specificity [22].…”