Age-specific prevalence of antibody to enterotoxigenic Escherichia coli in Ecuadorian and German children.

Serum samples from 1397 Ecuadorian children 0-5 years of age were tested by ELISA for antibodies to enterotoxigenic Escherichia coli (ETEC). A gradual prevalence and titer increase was seen for IgG antibodies to heat-labile enterotoxin in children 6-18 months old; 90% prevalences were reached in the second year of life. At this age less than 10% of West German children showed IgG antibodies to heat-labile enterotoxin. In Ecuador age-related ETEC-specific antibody titer increases correlated with age-related prevalence of diarrheal disease. On the other hand, pooled lipopolysaccharide from different ETEC-associated O serogroups could not be used as a seroepidemiologic marker of ETEC infections.