Pathogen-specific risk factors and protective factors for acute diarrheal illness in children aged 12-59 months in São Paulo, Brazil.

Diarrheal diseases are a leading cause of childhood morbidity and mortality in Latin America. Most studies have focused on infants but not on older children. We enrolled 505 children (age, 12-59 months) with diarrhea and age-matched controls in a case-control study in Sao Paulo, Brazil. Independent risk factors for diarrhea included another household member with diarrhea (matched odds ratio [mOR], 8.1; attributable fraction [AF], 0.17; P<.001) and consumption of homemade juice (mOR, 1.8; AF, 0.10; P=.01); protective factors included boiling of the baby bottle or nipple (mOR, 0.60; AF, 0.19; P=.026), childcare at home (mOR, 0.58; AF, 0.12; P=.004), and piped sewage (mOR, 0.58; AF, 0.05; P=.047). Hand washing by the caretaker after helping the child defecate protected against Shigella infection (mOR, 0.35; P<.05). Preparation of rice, beans, or soup in the morning and serving it to children after noon were associated with enterotoxigenic Escherichia coli infection (mOR, 8.0; P<.05). In these poor households, 28% of cases of diarrhea in 1-4-year-old children was attributable to easily modifiable exposures.