Wang Yuke, Yang Yang, Slanzi Crystal M, Li Xiaolong, Ojeda Amanda, Paro Fevi, Deblais Loïc, Yakubu Habib, Hassen Bahar Mummed, Game Halengo, Roba Kedir Teji, Schieber Elizabeth, Ibrahim Abdulmuen Mohammed, Wolyie Jeylan, Hassen Jemal Yusuf, Rajashekara Gireesh, McKune Sarah L, Havelaar Arie H, Moe Christine L, Liang Song
Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America.
Department of Statistics, Franklin College of Arts and Sciences, University of Georgia, Athens, Georgia, United States of America.
PLoS Negl Trop Dis. 2025 Jun 9;19(6):e0013154. doi: 10.1371/journal.pntd.0013154. eCollection 2025 Jun.
In low- and middle-income countries (LMICs), enteric infections pose a significant threat to children's health. However, understanding the specifics of when, where, and how young children in LMICs are exposed to enteric pathogens and the roles of animal reservoirs, environmental media, and human hosts play during exposure remains limited. This study systematically evaluates infants' exposure to E. coli through various pathways in the rural Haramaya woreda of Ethiopia. Between June 2021 and June 2022, we conducted over 1300 hours of structured behavioral observations on 79 infants when aged 4-8 months (Timepoint 1) and 11-15 months (Timepoint 2). Enumerators recorded the infant's behavior related to exposure, including when and where it occurred, using a data collection system for behavioral data (Countee). Concurrently, we collected 1338 environmental samples from key contact interfaces between infants, other people, and the environment to test for E. coli. We used a competing hazard model for duration-based behaviors, an inhomogeneous Poisson point process model for frequency-based behaviors, and a left-censored lognormal distribution model for E. coli contamination levels. The behavioral and environmental information was then integrated into an agent-based exposure model framework to quantify the exposure to E. coli through different pathways. The infant behavior, which altered the relative importance of different exposure pathways, changed as children grew older. Notably, we observed increased rates of touching behavior (e.g., touching fomites) and soil-pica, increased consumption of solid food, and more time spent on the bare ground at Timepoint 2. The major sources of exposure to E. coli were food and breastfeeding at Timepoint 1 and food and soil at Timepoint 2. This study provides insights for interventions to minimize infants' risk of exposure to fecal indicator bacteria, E. coli, and subsequent risk of enteric infections, including improved food handling practices, enhanced personal hygiene for breastfeeding caregivers, and education on the risk of soil-pica.
在低收入和中等收入国家（LMICs），肠道感染对儿童健康构成重大威胁。然而，对于LMICs中幼儿何时、何地以及如何接触肠道病原体，以及动物宿主、环境介质和人类宿主在接触过程中所起的作用，了解仍然有限。本研究系统评估了埃塞俄比亚哈拉马亚农村行政区婴儿通过各种途径接触大肠杆菌的情况。在2021年6月至2022年6月期间，我们对79名年龄在4至8个月（时间点1）和11至15个月（时间点2）的婴儿进行了超过1300小时的结构化行为观察。调查员使用行为数据收集系统（Countee）记录婴儿与接触相关的行为，包括接触发生的时间和地点。同时，我们从婴儿、其他人与环境之间的关键接触界面收集了1338份环境样本，以检测大肠杆菌。对于基于持续时间的行为，我们使用竞争风险模型；对于基于频率的行为，我们使用非齐次泊松点过程模型；对于大肠杆菌污染水平，我们使用左删失对数正态分布模型。然后，将行为和环境信息整合到基于主体的接触模型框架中，以量化通过不同途径接触大肠杆菌的情况。随着儿童年龄的增长，改变不同接触途径相对重要性的婴儿行为也发生了变化。值得注意的是，我们在时间点2观察到触摸行为（如触摸污染物）和食土癖的发生率增加、固体食物摄入量增加以及在裸露地面上花费的时间更多。在时间点1，接触大肠杆菌的主要来源是食物和母乳喂养；在时间点2，则是食物和土壤。本研究为采取干预措施以降低婴儿接触粪便指示菌大肠杆菌的风险以及随后发生肠道感染的风险提供了见解，包括改进食品处理方法、加强母乳喂养护理人员的个人卫生以及开展关于食土癖风险的教育。
