Diarrhoea, enteric pathogen detection and nutritional indicators among controls in the Global Enteric Multicenter Study, Kenya site: an opportunity to understand reference populations in case-control studies of diarrhoea

• Published in: Epidemiology and infection 2019-01, Vol.147, p.1, Article e44
• Main Authors: Berendes, D M, O'Reilly, C E, Kim, S, Omore, R, Ochieng, J B, Ayers, T, Fagerli, K, Farag, T H, Nasrin, D, Panchalingam, S, Nataro, J P, Kotloff, K L, Levine, M M, Oundo, J, Laserson, K, Breiman, R F, Mintz, E D
• Format: Article
• Language: English
• Subjects: Age; Children; Children & youth; Cholera; Complications; Developing countries; Diarrhea; Fever; Health care facilities; Hygiene; Illnesses; Incidence; Infections; Infectious diseases; Laboratories; LDCs; Original Paper; Pathogens; Population; Population studies; Questionnaires; Sanitation; Studies
• ISSN: 0950-2688; 1469-4409
• DOI: 10.1017/S0950268818002972

Given the challenges in accurately identifying unexposed controls in case-control studies of diarrhoea, we examined diarrhoea incidence, subclinical enteric infections and growth stunting within a reference population in the Global Enteric Multicenter Study, Kenya site. Within 'control' children (0-59 months old without diarrhoea in the 7 days before enrolment, n = 2384), we examined surveys at enrolment and 60-day follow-up, stool at enrolment and a 14-day post-enrolment memory aid for diarrhoea incidence. At enrolment, 19% of controls had ⩾1 enteric pathogen associated with moderate-to-severe diarrhoea ('MSD pathogens') in stool; following enrolment, many reported diarrhoea (27% in 7 days, 39% in 14 days). Controls with and without reported diarrhoea had similar carriage of MSD pathogens at enrolment; however, controls reporting diarrhoea were more likely to report visiting a health facility for diarrhoea (27% vs. 7%) or fever (23% vs. 16%) at follow-up than controls without diarrhoea. Odds of stunting differed by both MSD and 'any' (including non-MSD pathogens) enteric pathogen carriage, but not diarrhoea, suggesting control classification may warrant modification when assessing long-term outcomes. High diarrhoea incidence following enrolment and prevalent carriage of enteric pathogens have implications for sequelae associated with subclinical enteric infections and for design and interpretation of case-control studies examining diarrhoea.