Campylobacter colonization and undernutrition in infants in rural Eastern Ethiopia: a longitudinal community-based birth cohort study

Background: Campylobacter is associated with environmental enteric dysfunction (EED) and malnutrition in children. Campylobacter infection could be a critical link between determinants of livestock fecal exposure and health outcomes in low-resource smallholder settings. Methods: We followed a birth cohort of 106 infants in a community of rural smallholder households in eastern Ethiopia up to 13 months of age. We measured anthropometry, surveyed socio-demographic determinants, and collected stool and urine samples. A short survey was conducted during monthly visits, infant stool samples were collected, and Campylobacter spp. was quantified using genus-specific qPCR. In month 13, we collected stool and urine samples to assay for biomarkers of EED. We employed regression analyses to assess the associations of household determinants with Campylobacter colonization, EED, and growth faltering. Results: The Campylobacter load in infant stools increased with age. The mean length-for-age z-score (LAZ) decreased from -0.45 at 3-4 months of age to -2.06 at 13 months, while the prevalence of stunting increased from 3% to 51%. The prevalence of EED at 13 months of age was 56%. A higher Campylobacter load was associated with more frequent diarrhea. Prelacteal feeding significantly increased Campylobacter load in the first month of life. Over the whole follow-up period, Campylobacter load was increased by keeping chickens unconfined at home and unsanitary disposal of infant stools, while decreased by mothers handwashing with soap. Longitudinally, Campylobacter load was positively associated with food insecurity, introduction of complementary foods, and raw milk consumption. There were no significant associations between Campylobacter load, EED, and LAZ. Conclusions: This study found that most determinants associated with an increase in Campylobacter infection were related to suboptimal feeding practices and hygiene. Findings related to livestock-associated risks were inconclusive. Though stunting, EED, and Campylobacter prevalence rates all increased to high levels by the end of the first year of life, no significant association between them was identified. While additional research is needed to investigate whether findings from this study are replicated in other populations, community efforts to improve infant and young child feeding practices, including age at introduction of complementary foods and exclusive breastfeeding, and WaSH at the household level, could reduce (cross-) contamination at the point of exposure. ### Competing Interest Statement The authors have declared no competing interest. ### Clinical Protocols ### Funding Statement This project is funded by the United States Agency for International Development Bureau for Food Security under Agreement #AID-OAA-L-15-00003 as part of Feed the Future Innovation Lab for Livestock Systems, and by the Bill & Melinda Gates Foundation OPP#1175487. Under the grant conditions of the Foundation, a Creative Commons Attribution 4.0 Generic License has already been assigned to the Author Accepted Manuscript version that might arise from this submission. Any opinions, findings, conclusions, or recommendations expressed here are those of the authors alone. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Internal Review Board of the University of Florida (IRB201903141); the Institutional Health Research Ethics Committee at Haramaya University (COHMS/1010/3796/20), and the Ethiopia National Research Ethics Review Committee (SM/14.1/1059/20) each gave approval for this work. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Deidentified individual participant data will be made available through Dataverse (https://dataverse.org/) after December 31, 2024.