Kinetics of Enteric Pathogen Quantity During Acute Diarrhea in Children in Resource-Limited Settings

Lain W.J.; Elwood S.E.; Liu J.; McQuade E.T.R.; Kang G.; Kosek M.N.; Lima A.A.M.; Bessong P.O.; Samie A.; Haque R.; Mduma E.R.; Leite J.P.; Bodhidatta L.; Iqbal N.T.; Page N.; Kiwelu I.; Bhutta Z.A.; Ahmed T.; Houpt E.R.; Platts-Mills J.A. · Open Forum Infectious Diseases (2026) · DOI: 10.1093/ofid/ofag309

Resumen

Pathogen quantity kinetics during childhood diarrhea have implications for etiology ascertainment. Using a multisite cohort, we modeled quantitative PCR quantity by symptom duration. Rotavirus had the largest log reduction in quantity by day 7 (−1.98; 95% confidence interval: −2.88, −1.08), followed by Shigella (−0.87; −1.46, −.28) and heat-stable toxin-producing Escherichia coli (−0.78; −1.57, .02). While peak quantity was robust to host factors, kinetics were not. For example, malnourished children had a minimal decline in Cryptosporidium quantity over the first 7 days of illness. Pathogen quantity, etiology attribution, and non-PCR test sensitivity all peaked early in illness. Diarrheal studies should collect samples early to reduce bias in etiology identification. © The Author(s) 2026. Published by Oxford University Press on behalf of Infectious Diseases Society of America. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/).