Persistent Diarrhea in Developing Countries

Abstract

Globally diarrheal diseases account for almost a fifth of all deaths of children under 5 years, with an estimated 2.2 million deaths annually. Of these deaths, a significant proportion are related to episodes of persistent diarrhea (PD; defined as diarrhea of >14 days with growth faltering). PD has been shown to identify children with a substantially increased diarrheal burden. These account for 36–54% of all diarrhea-related deaths. Although the exact pathogenesis of PD remains unclear, most episodes are related to prior acute infectious diarrhea with prolongation of the most recent episode. This may be related to several host factors such as preexisting undernutrition, micronutrient deficiency, immune deficiency and inappropriate therapy of the most recent acute diarrheal episode. The common final event appears to be prolonged intestinal mucosal injury and ineffective repair. In contrast to post-infectious PD, some infants may have severe intractable diarrhea due to a variety of disorders, many of which have a hereditary basis. These now form the dominant type of prolonged diarrhea in developed countries. The management of PD depends upon close attention to nutritional rehabilitation and early recognition of complications. Although a variety of pathogens have been associated with PD, there is little role for oral antimicrobial therapy in the routine treatment of PD. However, attention to rehydration, appropriate screening and treatment of systemic infections and enteral nutrition rehabilitation with easily digestible diets are critical in managing such children, frequently in ambulatory settings. Administration of zinc and vitamin A may shorten the duration of PD and also help reduce recurrences. However, the most important preventive strategies for PD are exclusive breastfeeding in the first 6 months of life, continued breast feeding for 2 years with appropriate complementary feeding and optimal management of acute diarrheal episodes.