Journal Articles

Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7915

Browse

Filters

2020 - 202517

Settings

Start date: 2020Subject: search.filters.subject.Longitudinal Studies

Search Results

Now showing 1 - 10 of 18
  • Thumbnail Image
    Item
    Food Group Consumption and Nutrient Intake by Breastfeeding Women: Comparison to Current Dietary Guidelines and Nutrient Recommendations.
    (MDPI (Basel, Switzerland), 2025-01-21) Jin Y; Coad J; Brough L; Billeaud C; Asher O
    BACKGROUND/OBJECTIVES: Optimal nutrition is essential for the health of breastfeeding women and their infants. This study aimed to assess food and nutrient intake and alignment with nutrition guidelines for breastfeeding women living in New Zealand. METHODS: Seventy-six breastfeeding women were enrolled in the longitudinal Mother and Infant Nutrition Investigation study and completed a weighed four-day diet diary including supplement use at three months postpartum. The number of servings consumed for each food group were calculated based on the 2020 Eating and Activity Guidelines for New Zealand Adults. Nutrient intakes were compared to the nutrient reference values for Australia and New Zealand. RESULTS: Overall, the percentages of women who met the recommended number of servings for fruits, vegetables, grain foods, meats and milk/milk products were 25%, 0%, 5%, 34%, and 13%, respectively. None of women met the current recommendations for all food groups. Many participants had intakes below the estimated average requirement or adequate intake and were at risk of nutrient inadequacy for vitamin E (55%), vitamin D (53%), manganese (61%), and selenium (55%). CONCLUSIONS: Breastfeeding women had a low alignment with the current dietary guidelines and were at risk of an inadequate intake of vitamin E, D, manganese, and selenium. Research to investigate the barriers and enablers of healthy food choices is needed.
  • Thumbnail Image
    Item
    Campylobacter colonization and undernutrition in infants in rural eastern Ethiopia - a longitudinal community-based birth cohort study.
    (Frontiers Media S.A., 2025-01-07) Chen D; McKune SL; Yang Y; Usmane IA; Ahmed IA; Amin JK; Ibrahim AM; Seran AJ; Shaik N; Ojeda A; Hassen BM; Deblais L; Ahmedo BU; Hassen KA; Bhrane M; Li X; Singh N; Roba KT; French NP; Rajashekara G; Manary MJ; Hassen JY; Havelaar AH; CAGED Research Team
    Background: Campylobacter is associated with environmental enteric dysfunction (EED) and malnutrition in children. Campylobacter infection could be a linchpin between livestock fecal exposure and health outcomes in low-resource smallholder settings. Methods: We followed a birth cohort of 106 infants in rural smallholder households in eastern Ethiopia up to 13 months of age. We measured anthropometry, surveyed sociodemographic 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 EED biomarkers. 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. Conclusion: This study found that most determinants associated with increased Campylobacter infection were related to suboptimal feeding practices and hygiene. The findings related to livestock-associated risks were inconclusive. Although 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 replicable in other populations, community efforts to improve infant and young child feeding practices and food hygiene, and water, sanitation, and hygiene (WaSH) at the household level, could reduce (cross-)contamination at the point of exposure.
  • Thumbnail Image
    Item
    The relationship between hair metabolites, air pollution exposure and gestational diabetes mellitus: A longitudinal study from pre-conception to third trimester.
    (Frontiers Media S.A., 2022-12-02) Chen X; Zhao X; Jones MB; Harper A; de Seymour JV; Yang Y; Xia Y; Zhang T; Qi H; Gulliver J; Cannon RD; Saffery R; Zhang H; Han T-L; Baker PN; Zhou N
    BACKGROUND: Gestational diabetes mellitus (GDM) is a metabolic condition defined as glucose intolerance with first presentation during pregnancy. Many studies suggest that environmental exposures, including air pollution, contribute to the pathogenesis of GDM. Although hair metabolite profiles have been shown to reflect pollution exposure, few studies have examined the link between environmental exposures, the maternal hair metabolome and GDM. The aim of this study was to investigate the longitudinal relationship (from pre-conception through to the third trimester) between air pollution exposure, the hair metabolome and GDM in a Chinese cohort. METHODS: A total of 1020 women enrolled in the Complex Lipids in Mothers and Babies (CLIMB) birth cohort were included in our study. Metabolites from maternal hair segments collected pre-conception, and in the first, second, and third trimesters were analysed using gas chromatography-mass spectrometry (GC-MS). Maternal exposure to air pollution was estimated by two methods, namely proximal and land use regression (LUR) models, using air quality data from the air quality monitoring station nearest to the participant's home. Logistic regression and mixed models were applied to investigate associations between the air pollution exposure data and the GDM associated metabolites. RESULTS: Of the 276 hair metabolites identified, the concentrations of fourteen were significantly different between GDM cases and non-GDM controls, including some amino acids and their derivatives, fatty acids, organic acids, and exogenous compounds. Three of the metabolites found in significantly lower concentrations in the hair of women with GDM (2-hydroxybutyric acid, citramalic acid, and myristic acid) were also negatively associated with daily average concentrations of PM2.5, PM10, SO2, NO2, CO and the exposure estimates of PM2.5 and NO2, and positively associated with O3. CONCLUSIONS: This study demonstrated that the maternal hair metabolome reflects the longitudinal metabolic changes that occur in response to environmental exposures and the development of GDM.
  • Thumbnail Image
    Item
    Child abuse and neglect and mental health outcomes in adulthood by ethnicity: Findings from a 40-year longitudinal study in New Zealand/Aotearoa.
    (Elsevier B.V., 2023-11-01) Telfar S; McLeod GFH; Dhakal B; Henderson J; Tanveer S; Broad HET; Woolhouse W; Macfarlane S; Boden JM
    BACKGROUND: Longitudinal studies consistently report adverse long-term outcomes of childhood maltreatment. Little is known about the impact of childhood maltreatment on mental health among a marginalized population (New Zealand Māori); therefore, we cannot assume the effects of maltreatment are the same across the population. OBJECTIVE: Associations were examined between childhood sexual abuse (CSA), childhood physical punishment (CPP) and childhood neglect (CN) (<16 years) and mental health outcomes 18-40 years, by ethnicity (Māori/non-Māori). PARTICIPANTS AND SETTING: Data from the Christchurch Health and Development Study, a study of a birth cohort of 1265 children born in Christchurch in 1977. By age 40, 17.8 % (n = 191) reported New Zealand Māori ethnic identity; 82.2 % (n = 883) were non-Māori. METHODS: CSA, CPP (<16 years) were measured at 18, 21 years; CN was measured at 40 years. Major depression, anxiety disorder, suicidal ideation, alcohol abuse/dependence and cannabis abuse/dependence were measured at ages 21, 25, 30, 35 and 40 years. Childhood confounding variables controlled. Analyses were extended to include Māori ethnicity. RESULTS: After statistical adjustment, experience of severe childhood maltreatment increased odds of mental health problems 1.8-2.6×, compared to no maltreatment; the effects of maltreatment were similar for males and females. For Māori, some higher rates of mental health problems were seen among those maltreated, no statistically significant associations were detected after Bonferroni correction (among severe maltreatment vs. no maltreatment). Limitations should be considered when interpreting results. CONCLUSIONS: Exposure to childhood maltreatment has long-term effects into middle-age. Further research employing culturally-sensitive approaches may help clarify Māori childhood maltreatment outcomes.
  • Thumbnail Image
    Item
    Lifestyle for brain health and cognitive functioning in midlife to early late-life New Zealanders: Utility of the LIBRA index.
    (John Wiley and Sons, Inc., 2024-05-01) Röhr S; Stephens C; Alpass F
    OBJECTIVES: There is enormous potential to improve brain health and reduce the risk of cognitive decline and dementia based on modifiable risk factors. The Lifestyle for Brain Health (LIBRA) index was developed to quantify modifiable dementia risk or room for brain health improvement. The objective of the study was to investigate the utility of the LIBRA index in relation to cognitive functioning in a midlife to early late-life sample of New Zealanders. METHODS: A subsample (n = 1001) of the longitudinal New Zealand Health, Work and Retirement (NZHWR) study completed face-to-face cognitive assessments using the 'Kiwi' Addenbrooke's Cognitive Examination-Revised (ACE-R) in 2010 and again in 2012, in addition to completing biennial NZHWR surveys on socioeconomic, health and wellbeing aspects. The LIBRA index was calculated incorporating information on 8 out of 12 modifiable health and lifestyle factors for dementia. Unadjusted and adjusted regression models and mixed effects models were used to inspect associations of LIBRA with cognitive functioning, cognitive impairment, and cognitive decline. RESULTS: The analytical sample (n = 881 [88.0%], after considering exclusion criteria and missing data) had a mean age of 63.1 (SD = 6.5) years, 53.3% were female, 26.2% were Māori, and 61.7% were highly educated. Higher LIBRA scores (indicating higher modifiable dementia risk) were associated with lower cognitive functioning (B = -0.33, 95% CI = -0.52;-0.15, p < 0.001) and a higher likelihood of cognitive impairment (OR = 1.22, 95% CI = 1.04; 1.42, p = 0.013), but did not predict cognitive decline over 2 years (B = -0.03, 95% CI = -0.22; 0.16, p = 0.766), adjusted for age, age2, gender, education, and ethnicity. CONCLUSIONS: The LIBRA index indicated promising utility for quantifying modifiable dementia risk in midlife and early late-life New Zealanders. For local use, refinement of the LIBRA index should consider cultural differences in health and lifestyle risk factors, and further investigate its utility with a wider range of modifiable factors over a longer observation period.
  • Thumbnail Image
    Item
    Use of Antihypertensives, Blood Pressure, and Estimated Risk of Dementia in Late Life: An Individual Participant Data Meta-Analysis.
    (American Medical Association, 2023-09-12) Lennon MJ; Lam BCP; Lipnicki DM; Crawford JD; Peters R; Schutte AE; Brodaty H; Thalamuthu A; Rydberg-Sterner T; Najar J; Skoog I; Riedel-Heller SG; Röhr S; Pabst A; Lobo A; De-la-Cámara C; Lobo E; Bello T; Gureje O; Ojagbemi A; Lipton RB; Katz MJ; Derby CA; Kim KW; Han JW; Oh DJ; Rolandi E; Davin A; Rossi M; Scarmeas N; Yannakoulia M; Dardiotis T; Hendrie HC; Gao S; Carrière I; Ritchie K; Anstey KJ; Cherbuin N; Xiao S; Yue L; Li W; Guerchet MM; Preux P-M; Aboyans V; Haan MN; Aiello AE; Ng TP; Nyunt MSZ; Gao Q; Scazufca M; Sachdev PSS
    IMPORTANCE: The utility of antihypertensives and ideal blood pressure (BP) for dementia prevention in late life remains unclear and highly contested. OBJECTIVES: To assess the associations of hypertension history, antihypertensive use, and baseline measured BP in late life (age >60 years) with dementia and the moderating factors of age, sex, and racial group. DATA SOURCE AND STUDY SELECTION: Longitudinal, population-based studies of aging participating in the Cohort Studies of Memory in an International Consortium (COSMIC) group were included. Participants were individuals without dementia at baseline aged 60 to 110 years and were based in 15 different countries (US, Brazil, Australia, China, Korea, Singapore, Central African Republic, Republic of Congo, Nigeria, Germany, Spain, Italy, France, Sweden, and Greece). DATA EXTRACTION AND SYNTHESIS: Participants were grouped in 3 categories based on previous diagnosis of hypertension and baseline antihypertensive use: healthy controls, treated hypertension, and untreated hypertension. Baseline systolic BP (SBP) and diastolic BP (DBP) were treated as continuous variables. Reporting followed the Preferred Reporting Items for Systematic Review and Meta-Analyses of Individual Participant Data reporting guidelines. MAIN OUTCOMES AND MEASURES: The key outcome was all-cause dementia. Mixed-effects Cox proportional hazards models were used to assess the associations between the exposures and the key outcome variable. The association between dementia and baseline BP was modeled using nonlinear natural splines. The main analysis was a partially adjusted Cox proportional hazards model controlling for age, age squared, sex, education, racial group, and a random effect for study. Sensitivity analyses included a fully adjusted analysis, a restricted analysis of those individuals with more than 5 years of follow-up data, and models examining the moderating factors of age, sex, and racial group. RESULTS: The analysis included 17 studies with 34 519 community dwelling older adults (20 160 [58.4%] female) with a mean (SD) age of 72.5 (7.5) years and a mean (SD) follow-up of 4.3 (4.3) years. In the main, partially adjusted analysis including 14 studies, individuals with untreated hypertension had a 42% increased risk of dementia compared with healthy controls (hazard ratio [HR], 1.42; 95% CI 1.15-1.76; P = .001) and 26% increased risk compared with individuals with treated hypertension (HR, 1.26; 95% CI, 1.03-1.53; P = .02). Individuals with treated hypertension had no significant increased dementia risk compared with healthy controls (HR, 1.13; 95% CI, 0.99-1.28; P = .07). The association of antihypertensive use or hypertension status with dementia did not vary with baseline BP. There was no significant association of baseline SBP or DBP with dementia risk in any of the analyses. There were no significant interactions with age, sex, or racial group for any of the analyses. CONCLUSIONS AND RELEVANCE: This individual patient data meta-analysis of longitudinal cohort studies found that antihypertensive use was associated with decreased dementia risk compared with individuals with untreated hypertension through all ages in late life. Individuals with treated hypertension had no increased risk of dementia compared with healthy controls.
  • Thumbnail Image
    Item
    Social connections and risk of incident mild cognitive impairment, dementia, and mortality in 13 longitudinal cohort studies of ageing.
    (Wiley Periodicals LLC on behalf of Alzheimer’s Association., 2023-11) Mahalingam G; Samtani S; Lam BCP; Lipnicki DM; Lima-Costa MF; Blay SL; Castro-Costa E; Shifu X; Guerchet M; Preux P-M; Gbessemehlan A; Skoog I; Najar J; Sterner TR; Scarmeas N; Yannakoulia M; Dardiotis T; Kim K-W; Riedel-Heller S; Röhr S; Pabst A; Shahar S; Numbers K; Ganguli M; Hughes TF; Chang C-CH; Crowe M; Ng TP; Gwee X; Chua DQL; Rymaszewska J; Wolf-Ostermann K; Welmer A-K; Stafford J; Mélis R; Vernooij-Dassen M; Jeon Y-H; Sachdev PS; Brodaty H; SHARED consortium for the Cohort Studies of Memory in an International Consortium (COSMIC)
    INTRODUCTION: Previous meta-analyses have linked social connections and mild cognitive impairment, dementia, and mortality. However, these used aggregate data from North America and Europe and examined a limited number of social connection markers. METHODS: We used individual participant data (N = 39271, Mage  = 70.67 (40-102), 58.86% female, Meducation  = 8.43 years, Mfollow-up  = 3.22 years) from 13 longitudinal ageing studies. A two-stage meta-analysis of Cox regression models examined the association between social connection markers with our primary outcomes. RESULTS: We found associations between good social connections structure and quality and lower risk of incident mild cognitive impairment (MCI); between social structure and function and lower risk of incident dementia and mortality. Only in Asian cohorts, being married/in a relationship was associated with reduced risk of dementia, and having a confidante was associated with reduced risk of dementia and mortality. DISCUSSION: Different aspects of social connections - structure, function, and quality - are associated with benefits for healthy aging internationally. HIGHLIGHTS: Social connection structure (being married/in a relationship, weekly community group engagement, weekly family/friend interactions) and quality (never lonely) were associated with lower risk of incident MCI. Social connection structure (monthly/weekly friend/family interactions) and function (having a confidante) were associated with lower risk of incident dementia. Social connection structure (living with others, yearly/monthly/weekly community group engagement) and function (having a confidante) were associated with lower risk of mortality. Evidence from 13 longitudinal cohort studies of ageing indicates that social connections are important targets for reducing risk of incident MCI, incident dementia, and mortality. Only in Asian cohorts, being married/in a relationship was associated with reduced risk of dementia, and having a confidante was associated with reduced risk of dementia and mortality. Highlights Social connection structure (being married/in a relationship, weekly community group engagement, weekly family/friend interactions) and quality (never lonely) were associated with lower risk of incident MCI. Social connection structure (monthly/weekly friend/family interactions) and function (having a confidante) were associated with lower risk of incident dementia. Social connection structure (living with others, yearly/monthly/weekly community group engagement) and function (having a confidante) were associated with lower risk of mortality. Evidence from 13 longitudinal cohort studies of ageing indicates that social connections are important targets for reducing risk of incident MCI, incident dementia, and mortality. Only in Asian cohorts, being married/in a relationship was associated with reduced risk of dementia, and having a confidante was associated with reduced risk of dementia and mortality.
  • Thumbnail Image
    Item
    Prevalence and Load of the Campylobacter Genus in Infants and Associated Household Contacts in Rural Eastern Ethiopia: a Longitudinal Study from the Campylobacter Genomics and Environmental Enteric Dysfunction (CAGED) Project
    (American Society for Microbiology, 2023-07-26) Deblais L; Ojeda A; Brhane M; Mummed B; Hassen KA; Ahmedo BU; Weldesenbet YD; Amin JK; Ahmed IA; Usmane IA; Yusuf EA; Seran AJ; Abrahim FI; Game HT; Mummed BA; Usmail MM; Umer KA; Dawid MM; Gebreyes W; French N; Hassen JY; Roba KT; Mohammed A; Yimer G; Saleem C; Chen D; Singh N; Manary MJ; McKune SL; Havelaar AH; Rajashekara G; Elkins CA
    In our previous cross-sectional study, multiple species of Campylobacter were detected (88%) in stool samples from children (12 to 14 months of age) in rural eastern Ethiopia. This study assessed the temporal fecal carriage of Campylobacter in infants and identified putative reservoirs associated with these infections in infants from the same region. The prevalence and load of Campylobacter were determined using genus-specific real-time PCR. Stool samples from 106 infants (n = 1,073) were collected monthly from birth until 376 days of age (DOA). Human stool samples (mothers and siblings), livestock feces (cattle, chickens, goats, and sheep), and environmental samples (soil and drinking water) from the 106 households were collected twice per household (n = 1,644). Campylobacter was most prevalent in livestock feces (goats, 99%; sheep, 98%; cattle, 99%; chickens, 93%), followed by human stool samples (siblings, 91%; mothers, 83%; infants, 64%) and environmental samples (soil, 58%; drinking water, 43%). The prevalence of Campylobacter in infant stool samples significantly increased with age, from 30% at 27 DOA to 89% at 360 DOA (1% increase/day in the odds of being colonized) (P < 0.001). The Campylobacter load increased linearly (P < 0.001) with age from 2.95 logs at 25 DOA to 4.13 logs at 360 DOA. Within a household, the Campylobacter load in infant stool samples was positively correlated with the load in mother stool samples (r2 = 0.18) and soil collected inside the house (r2 = 0.36), which were in turn both correlated with Campylobacter loads in chicken and cattle feces (0.60 < r2 < 0.63) (P < 0.01). In conclusion, a high proportion of infants are infected with Campylobacter in eastern Ethiopia, and contact with the mother and contaminated soil may be associated with early infections. IMPORTANCE A high Campylobacter prevalence during early childhood has been associated with environmental enteric dysfunction (EED) and stunting, especially in low-resource settings. Our previous study demonstrated that Campylobacter was frequently found (88%) in children from eastern Ethiopia; however, little is known about potential Campylobacter reservoirs and transmission pathways leading to infection of infants by Campylobacter during early growth. In the longitudinal study presented here, Campylobacter was frequently detected in infants within the 106 surveyed households from eastern Ethiopia, and the prevalence was age dependent. Furthermore, preliminary analyses highlighted the potential role of the mother, soil, and livestock in the transmission of Campylobacter to the infant. Further work will explore the species and genetic composition of Campylobacter in infants and putative reservoirs using PCR and whole-genome and metagenomic sequencing. The findings from these studies can lead to the development of interventions to minimize the risk of transmission of Campylobacter to infants and, potentially, EED and stunting.
  • Thumbnail Image
    Item
    Longitudinal study of herd udder hygiene and its association with clinical mastitis in pasture-based dairy cows
    (Elsevier Inc and the Federation of Animal Science Societies (FASS) Inc on behalf of the American Dairy Science Association, 2021-05) Rowe S; Tranter W; Laven R
    The objectives of this exploratory study were to (1) describe the association between herd-level udder hygiene and clinical mastitis and (2) investigate how sample size and milking stage affect the accuracy and precision of herd udder hygiene assessments made at milking time. A prospective longitudinal study was conducted in a dairy herd in Northern Australia as part of a previously published clinical trial of premilking teat disinfection. Video footage from 35 afternoon milkings was used to conduct 12,544 udder hygiene scores from 504 cows during an 89-d period and measure udder hygiene of the herd (proportion of cows with udder hygiene ≥3 out of 4). Linear interpolation was used to estimate herd udder hygiene on the days that were not scored, such that a herd-level udder hygiene measure was available for all cow-days in the study. Clinical mastitis events occurring during the study period were detected and recorded by farm staff according to a standardized definition. The relationship between herd udder hygiene on each of 1, 2, and 3 d before each study day (d -1, -2, and -3, respectively) and clinical mastitis at the cow level on each study day (each in turn being set as d 0) was determined using multivariable generalized estimating equations (family = Poisson, link = log), with the unit of analysis being the cow-day, adjusting for potential confounders and the clustering within the data. In addition, sampling strategies were evaluated by simulating herd udder hygiene assessments using a subset of cows in the herd. Herd udder hygiene from d -1, -2, and -3 was positively associated with clinical mastitis on d 0 (incidence rate ratio = 1.4 per 10-point increase in the percentage of cows with poor udder hygiene). Sampling strategy simulation found that at least 80 cows needed to be scored to achieve sufficiently precise estimations of herd udder hygiene. Furthermore, cows scored later during milking were slightly more likely to have poor udder hygiene than those scored earlier (risk ratio = 1.02 for cows that were 10% later in the milking order). More research is needed to evaluate risk factors for poor udder hygiene and potential interventions in pasture-based dairy cows.
  • Thumbnail Image
    Item
    Unravelling the reservoirs for colonisation of infants with Campylobacter spp. in rural Ethiopia: protocol for a longitudinal study during a global pandemic and political tensions.
    (BMJ Publishing Group Ltd, 2022-10-05) Havelaar AH; Brhane M; Ahmed IA; Kedir J; Chen D; Deblais L; French N; Gebreyes WA; Hassen JY; Li X; Manary MJ; Mekuria Z; Ibrahim AM; Mummed B; Ojeda A; Rajashekara G; Roba KT; Saleem C; Singh N; Usmane IA; Yang Y; Yimer G; McKune S
    INTRODUCTION: Undernutrition is an underlying cause of mortality in children under five (CU5) years of age. Animal-source foods have been shown to decrease malnutrition in CU5. Livestock are important reservoirs for Campylobacter bacteria, which are recognised as risk factors for child malnutrition. Increasing livestock production may be beneficial for improving nutrition of children but these benefits may be negated by increased exposure to Campylobacter and research is needed to evaluate the complex pathways of Campylobacter exposure and infection applicable to low-income and middle-income countries. We aim to identify reservoirs of infection with Campylobacter spp. of infants in rural Eastern Ethiopia and evaluate interactions with child health (environmental enteric dysfunction and stunting) in the context of their sociodemographic environment. METHODS AND ANALYSIS: This longitudinal study involves 115 infants who are followed from birth to 12 months of age and are selected randomly from 10 kebeles of Haramaya woreda, East Hararghe zone, Oromia region, Ethiopia. Questionnaire-based information is obtained on demographics, livelihoods, wealth, health, nutrition and women empowerment; animal ownership/management and diseases; and water, sanitation and hygiene. Faecal samples are collected from infants, mothers, siblings and livestock, drinking water and soil. These samples are analysed by a range of phenotypic and genotypic microbiological methods to characterise the genetic structure of the Campylobacter population in each of these reservoirs, which will support inference about the main sources of exposure for infants. ETHICS AND DISSEMINATION: Ethical approval was obtained from the University of Florida Internal Review Board (IRB201903141), the Haramaya University Institutional Health Research Ethics Committee (COHMS/1010/3796/20) and the Ethiopia National Research Ethics Review Committee (SM/14.1/1059/20). Written informed consent is obtained from all participating households. Research findings will be disseminated to stakeholders through conferences and peer-reviewed journals and through the Feed the Future Innovation Lab for Livestock Systems.