The Etiology of Diarrheal Illness in a Sub-Saharan African Country

Abstract

Purpose: Diarrheal illness is a major cause of mortality for children in Africa; however, the epidemiology is understudied and varies from country to country. The purpose is to describe the etiology of diarrheal diseases at an outpatient facility and an inpatient ward in Malawi, Africa. Methods: We performed a retrospective study of consecutive subjects from ages 4 to 60 months admitted to Kamazu Central Hospital in Lilongwe, Malawi, with the principle diagnosis of diarrhea seen during a one-month period. A second cohort of consecutive subjects of the same ages presenting to MARS Clinic, an outpatient clinic in Lilongwe, Malawi, with a chief complaint of diarrhea was also assessed. Charts were reviewed for demographic information, mode of work-up, and any pathogens isolated. Comparisons were made between inpatients and outpatients using Student's t-tests and X2 analysis. Results: Thirty children (mean age 15.3 months) were admitted to the ward, and 28 (mean age 33.0 months) were assessed at the outpatient clinic during the study period (p = 0.0006). Less than half of patients had stool cultures. Blood smears for malaria were performed on 21 (70%) inpatients vs. 22 (79%) outpatients (p = NS). In 19/30 (63.3%) inpatients and 11/28 (39.3%) outpatients, at least one diarrhea-causing pathogen was isolated. Of those patients, the most common etiology was malaria, affecting 19/19 (100%) inpatients and 3/10 (30.0%) outpatients. Other etiologies of infectious diarrhea included bacterial gastroenteritis [2/30 (6.6%) inpatients and 7/28 (25.0%) outpatients]; viral gastroenteritis [1/30 (3%) inpatients and 10/28 (35.7%) outpatients]; and Giardia lamblia[1/30 (3%) inpatients and 3/28 (10.7%) outpatients]. In 11/30 (36.6%) inpatients and 18/28 (64.3%) outpatients, no etiology of the diarrhea was identified. Eleven of 30 (36.6%) inpatients and 17 of 28 (60.7%) outpatients were treated empirically. The most common medications for empiric treatment were oral rehydration salts (15/58, 25.9%), cotrimoxazole (11/58, 19.0%) and paracetamol (13/58, 22.4%). Of the 30 subjects admitted to the hospital with diarrheal illness, 4 (13%) died of their disease. Conclusions: Pediatric diarrheal illness is a common cause of both inpatient admission and outpatient consultation in Malawi. A significant proportion of patients presenting with diarrhea have minimal work-up and undergo empiric therapy. Of those subjects in whom a pathogen is isolated, malaria is the most common diarrhea-inducing pathogen. Death from diarrheal disease occurred in more than 10% of the inpatient population.