Early childhood diarrhea is associated with diminished cognitive function 4 to 7 years later in children in a northeast Brazilian shantytown

Diarrhoea is well recognized as a leading cause of childhood mortality and morbidity in developing countries; however, possible long-term cognitive deficits from heavy diarrhoea burdens in early childhood remain poorly defined. To assess the potential long-term impact of early childhood diarrhoea (in the first 2 years of life) on cognitive function in later childhood, we studied the cognitive function of a cohort of children in an urban Brazilian shantytown with a high incidence of early childhood diarrhoea. Forty-six children (age range, 6-10 years) with complete diarrhoea surveillance during their first 2 years of life were given a battery of five cognitive tests. Test of Non-Verbal Intelligence-
III (TONI) scores were inversely correlated with early childhood diarrhoea (P =.01), even when controlling for maternal education, duration of breast-feeding, and early childhood helminthiasis (Ascaris or Trichuris). Furthermore, Wechsler Intelligence Scale for Children (WISC-III) Coding Tasks and WISC-III Digit Span (reverse and total) scores were also significantly lower in the 17 children with a history of early childhood persistent diarrhoea (PD; P