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