Persistent Diarrhea in Children in Developing Countries

Persistent diarrhea continues to pose enormous challenges globally. With the substantial overall reduction in childhood mortality from acute diarrhea, the share of mortality due to persistent diarrhea is rising. It is therefore more important now to know how best to define, diagnose, triage, and treat persistent diarrhea. As the duration of illness lengthens, malnutrition becomes increasingly manifest and this relationship is bidirectional. Many, but not all, episodes of persistent diarrhea are infectious in origin, and the responsible organisms depend on endemicity. A few common pathogens have been particularly associated with persistent diarrhea, including bacteria (Aeromonas, Campylobacter, Clostridium difficile, Escherichia coli, Plesiomonas, Salmonella, Shigella), parasites (Cryptosporidium, Cyclospora, Entamoeba histolytica, Giardia, Microsporidia), and viruses (rotavirus, norovirus). Treatment is focused on reversing dehydration (if present), nutritional interventions including balanced protein energy and micronutrient supplements, pancreatic enzyme replacement therapy (PERT), and judicious use of antibiotics for certain types of inflammatory diarrhea. Strategies should also be directed toward preventing concurrent infections and identifying optimal diets to prevent persistent diarrhea. Multidisciplinary research into the epidemiology, host response, etiology, and treatment of persistent diarrhea is needed.