Persistent diarrhea signals a critical period of increased diarrhea burdens and nutritional shortfalls: A prospective cohort study among children in northeastern Brazil

Persistent diarrhea (PD; duration greater than or equal to 14 days) is a gr owing part of the global burden of diarrheal diseases. A 45-month prospecti ve cohort study (with illness, nutritional, and microbiologic surveillance) was conducted in a shantytown in northeastern Brazil, to elucidate the epi demiology, nutritional impact, and causes of PD in early childhood (0-3 yea rs of age). A nested case-control design was used to examine children's dia rrhea burden and nutritional status before and after a first PD illness. PD illnesses accounted for 8% of episodes and 34% of days of diarrhea, First PD illnesses were preceded by a doubling of acute diarrhea burdens, were fo llowed by further 2.6-3.5-fold increased diarrhea burdens for 18 months, an d were associated with acute weight shortfalls. Exclusively breast-fed chil dren had 8-fold lower diarrhea rates than did weaned children. PD-associate d etiologic agents included Cryptosporidium, Giardia, enteric adenoviruses, and enterotoxigenic Escherichia coli, PD signals growth shortfalls and inc reased diarrhea burdens; children with PD merit extended support, and the i llness warrants further study to elucidate its prevention, treatment, and i mpact.