Characterization of enteric disease in children by use of a low-cost specimen preservation method

Diarrhea is a leading cause of death in children under five. Molecular methods exist for the rapid detection of enteric pathogens; however, the logistical costs of storing stool specimens limit applicability. We sought to demonstrate that dried specimens preserved using filter paper can be used to identify diarrheal diseases causing significant morbidity among children in resource-constrained countries. A substudy was nested into cholera surveillance in Cameroon. Enrollment criteria included enrollment between 1 August 2016 and 1 October 2018, age of ,18 years, availability of a stool specimen, and having three or more loose stools within 24 h with the presence of dehydration and/or blood. A total of 7,227 persons were enrolled, of whom 2,746 met enrollment criteria and 337 were included in this analysis using the enteric TaqMan array card. Bacterial pathogens were compared to severity of diarrhea, age, and sex, among other variables. One hundred seven were positive for enterotoxigenic Escherichia coli, of which 40.2% (n = 43) had heat-labile enterotoxin (LT) and the heatstable enterotoxin STh, 19.6% (n = 21) had LT and the heat-stable enterotoxin STp, and 49.5% (n = 53) had LT only. Major colonization factors (CFs) were present in 43.9% of enterotoxigenic E. coli (ETEC)-positive patients. Ninety-six were positive for Shigella, of whom 14 (14.6%) reported dysentery. Model-derived quantitative cutoffs identified 116 (34.4%) with one highly diarrhea-associated pathogen and 16 (4.7%) with two or more. Shigella and rotavirus were most strongly associated with diarrhea in children with mixed infections. Dried-filter-paper-preserved specimens eliminate the need for frozen stool specimens and will facilitate enteric surveillance and contribute to the understanding of disease burden, which is needed to guide vaccine development and introduction. This study confirms rotavirus, Shigella, and ETEC as major contributors to pediatric diarrheal disease in two regions of Cameroon.