Prolonged Episodes of Acute Diarrhea Reduce Growth and Increase Risk of Persistent Diarrhea in Children

Abstract

Background & Aims Prolonged episodes of acute diarrhea (ProD, duration 7–13 days) or persistent diarrhea (PD, duration ≥14 days) are important causes of undernutrition, yet the epidemiology and nutritional impact of ProD are poorly understood. Methods We conducted a 10-year cohort study of 414 children from a Brazilian shantytown who were followed from birth; data were collected on diarrhea, enteric pathogens, and anthropometry. Results During 1,276 child-years of observation, we recorded 3,257 diarrheal episodes. ProD was twice as common as PD (12% and 5% of episodes, respectively); ProD and PD together accounted for 50% of all days with diarrhea. ProD was more common in infants whose mothers had not completed primary school (relative risk [RR]=2.1; 95% confidence interval=1.02–2.78). Early weaning was associated with earlier onset of ProD (Spearman's ρ, 0.309; P=0.005). Infants with ProD were twice as likely to develop PD in later childhood (log rank P=0.002) compared to infants with only acute diarrhea (AD, duration <7 days), even after controlling for confounders. Children's growth was more severely stunted before their first episode of ProD, compared with AD (mean height-for-age Z score (HAZ) -0.81 vs. -0.51, P<0.05, unpaired t test). Following ProD, HAZ (ΔHAZ=-0.232) and weight-for-age (ΔWAZ=-0.26) significantly decreased (P<0.005 in paired t tests). ProD was associated with Cryptosporidium and Shigella infections. Conclusions ProD accounts for significant morbidity and identifies children at risk of a vicious cycle of diarrhea and malnutrition. Further studies are needed to address the recognition and control of ProD and its consequences in resource-limited settings and assess its role in PD pathogenesis.