Prevalence and immune response to Entamoeba histolytica infection in preschool children in Bangladesh.

Entamoeba histolytica infection was present in 5% and E. dispar in 13% of asymptomatic 2-5-year-old children from an urban slum of Dhaka, Bangladesh. Entamoeba dispar-infected children were no more likely than uninfected children to have serum antibodies to lectin. In contrast, all children infected with E. histolytica had serum antibodies to lectin. This anti-lectin response included antibodies against the carbohydrate recognition domain, which have been demonstrated in animal models to confer passive protection from amebiasis. Antibodies to lectin persisted in the sera of 17 children with E. histolytica infection over one year of follow-up, during which time E. histolytica infection cleared without treatment in 15, and with anti-amebic medication in two. We conclude that half of the children in this population have serologic evidence of amebiasis by five years of age, and that an anti-lectin serum antibody response is associated with limitation of E. histolytica infection to the colon.