Prenatal Exposure to p,p-DDE and Incidence of Diarrhea among Young Boys from a Highly Exposed Area of Mexico

Background. A higher risk of acute gastrointestinal infections has been reported among children with prenatal exposure to p,p’-DDE, the main and most persistent breakdown product of the pesticide DDT. DDT’s potential immunotoxic effects might explain such associations. We assessed whether prenatal exposure to p,p’-DDE and p,p’-DDT was associated with a higher risk of diarrhea in young boys from Chiapas, a highly exposed area of Mexico. Methods. We analyzed data from 747 singleton boys whose prenatal exposure to p,p’-DDE and p,p’-DDT was measured in maternal serum drawn at delivery (2002-2003). Diarrhea episodes experienced by the children were reported by their mothers during in-person interviews. The median age of the children at their last interview was 21.4 months (quartiles 19.1 and 25.3 months). The incidence rate ratio of diarrhea by prenatal exposure to p,p’-DDE and p,p’-DDT was estimated using Poisson regression with robust standard errors to adjust for the clustering of observations within childr...