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This paper investigates the demographic and socio-economic correlates of dietary patterns in South Africa, drawing on a sample of young adults experiencing internal migration and urbanisation. We use data from the 2018 baseline survey of the Migrant Health Follow-Up Study, an original longitudinal cohort study consisting of 3,087 internal migrants and rural residents aged 18–40 nested within the Agincourt Health and socio-Demographic Surveillance System in rural northeast South Africa. We employ principal components analysis to identify dietary patterns from food frequency questionnaires and ordinary least squares regression to assess whether migration and other socio-economic characteristics correlate with specific dietary patterns at baseline. We observe five distinct dietary patterns characterised by frequent consumption of processed foods, red meat, fruits and vegetables, diverse foods, and high sugar/fat foods. We find migration to be significantly associated with more frequent consumption of both processed foods and fruits and vegetables; we also find the association between migration status and dietary patterns to be heterogenous depending on migrants’ destinations. This paper extends current understanding of changing dietary patterns in the context of nutrition transitions with attention to dynamic migration processes rather than static rural-urban differences.

Abstract Genome-wide association studies (GWAS) have become well-powered to detect loci associated with telomere length. However, no prior work has validated genes nominated by GWAS to examine their role in telomere length regulation. We conducted a multi-ancestry meta-analysis of 211,369 individuals and identified five novel association signals. Enrichment analyses of chromatin state and cell-type heritability suggested that blood/immune cells are the most relevant cell type to examine telomere length association signals. We validated specific GWAS associations by overexpressing KBTBD6 or POP5 and demonstrated that both lengthened telomeres. CRISPR/Cas9 deletion of the predicted causal regions in K562 blood cells reduced expression of these genes, demonstrating that these loci are related to transcriptional regulation of KBTBD6 and POP5. Our results demonstrate the utility of telomere length GWAS in the identification of telomere length regulation mechanisms and validate KBTBD6 and POP5 as genes affecting telomere length regulation.

Abstract Introduction Outside of pregnancy, evidence shows that persons with HIV initiating or switching to dolutegravir (DTG)‐based antiretroviral therapy (ART) experience greater weight gain compared to those on other ART classes. However, there are few data on the impact of DTG‐based ART on gestational weight gain (GWG) in sub‐Saharan Africa where HIV is most common. According to the National Academy of Medicine (NAM), GWG below and above NAM guidelines is associated with adverse birth outcomes. Therefore, the objective of this study was to describe GWG by HIV status and ART regimen, and examine the associations with adverse birth outcomes. Methods We enrolled pregnant women with HIV (WHIV) and without HIV (≥18 years) in a peri‐urban primary healthcare facility in Cape Town, South Africa between 2019 and 2022. GWG was study‐measured at 24–28 (baseline) and 33–38 weeks gestation and converted to GWG rate (kg/week) in accordance with NAM guidelines. GWG z‐scores were generated using the INTEGROWTH‐21 and US standards to account for differing lengths of gestation. Birth outcome data were obtained from medical records. Associations of GWG z‐score with adverse birth outcomes were assessed using multivariable linear or log‐binomial regression. Results Among 292 participants (48% WHIV), median age was 29 years (IQR, 25–33), median pre‐pregnancy body mass index (BMI) was 31 kg/m2 (IQR, 26–36) and 20% were primiparous at baseline. The median weekly rate of GWG was 0.30 kg/week (IQR, 0.12–0.50), 35% had GWG below NAM standards (59% WHIV) and 48% had GWG above NAM standards (36% WHIV). WHIV gained weight more slowly (0.25 vs. 0.37 kg/week, p4000 g (RR = 2.18 95% CI 1.18, 4.01). Conclusions Despite slower GWG among WHIV, nearly half of all women gained weight faster than recommended by the NAM. GWG was positively associated with infant birth weight. Interventions to support healthy GWG in sub‐Saharan Africa are urgently needed.

Although the common genetic variants contributing to blood lipid levels have been studied, the contribution of rare variants is less understood. Here, the authors perform a rare coding and noncoding variant association study of blood lipid levels using whole genome sequencing data.

Summary: Identifying population-specific genetic variants associated with disease and disease-predisposing traits is important to provide insights into the genetic determinants of health and disease between populations, as well as furthering genomic justice. Various common pan-population polymorphisms at CETP associate with serum lipid profiles and cardiovascular disease. Here, sequencing of CETP identified a missense variant rs1597000001 (p.Pro177Leu) specific to Māori and Pacific people that associates with higher HDL-C and lower LDL-C levels. Each copy of the minor allele associated with higher HDL-C by 0.236 mmol/L and lower LDL-C by 0.133 mmol/L. The rs1597000001 effect on HDL-C is comparable with CETP Mendelian loss-of-function mutations that result in CETP deficiency, consistent with our data, which shows that rs1597000001 lowers CETP activity by 27.9%. This study highlights the potential of population-specific genetic analyses for improving equity in genomics and health outcomes for population groups underrepresented in genomic studies.

This study of 23,000 non-diabetic individuals highlights loci associated with fasting glucose and fasting insulin in diverse cohorts with whole genome sequence data.

Abstract Background While large genome-wide association studies have identified nearly one thousand loci associated with variation in blood pressure, rare variant identification is still a challenge. In family-based cohorts, genome-wide linkage scans have been successful in identifying rare genetic variants for blood pressure. This study aims to identify low frequency and rare genetic variants within previously reported linkage regions on chromosomes 1 and 19 in African American families from the Trans-Omics for Precision Medicine (TOPMed) program. Genetic association analyses weighted by linkage evidence were completed with whole genome sequencing data within and across TOPMed ancestral groups consisting of 60,388 individuals of European, African, East Asian, Hispanic, and Samoan ancestries. Results Associations of low frequency and rare variants in RCN3 and multiple other genes were observed for blood pressure traits in TOPMed samples. The association of low frequency and rare coding variants in RCN3 was further replicated in UK Biobank samples (N = 403,522), and reached genome-wide significance for diastolic blood pressure (p = 2.01 × 10− 7). Conclusions Low frequency and rare variants in RCN3 contributes blood pressure variation. This study demonstrates that focusing association analyses in linkage regions greatly reduces multiple-testing burden and improves power to identify novel rare variants associated with blood pressure traits.

IntroductionIn sub-Saharan African settings, the increasing non-communicable disease mortality is linked to migration, which disproportionately exposes sub-populations to risk factors for co-occurring HIV and NCDs.MethodsWe examined the prevalence, patterns, and factors associated with two or more concurrent diagnoses of chronic diseases (i.e., multimorbidity) among temporary within-country migrants. Employing a cross-sectional design, our study sample comprised 2144 residents and non-residents 18–40 years interviewed and with measured biomarkers in 2018 in Wave 1 of the Migrant Health Follow-up Study (MHFUS), drawn from the Agincourt Health and Demographic Surveillance System (AHDSS) in rural north-eastern South Africa. We used modified Poisson regression models to estimate the association between migration status and prevalent chronic multimorbidity conditional on age, sex, education, and healthcare utilisation.ResultsOverall, 301 participants (14%; 95% CI 12.6–15.6), median age 31 years had chronic multimorbidity. Multimorbidity was more prevalent among non-migrants (14.6%; 95% CI 12.8–16.4) compared to migrants (12.8%; 95% CI 10.3–15.7). Non-migrants also had the greatest burden of dual-overlapping chronic morbidities, such as HIV-obesity 5.7%. Multimorbidity was 2.6 times as prevalent (PR 2.65. 95% CI 2.07–3.39) among women compared to men. Among migrants, men, and individuals with secondary or tertiary education manifested lower prevalence of two or more conditions.DiscussionIn a rural community with colliding epidemics, we found low but significant multimorbidity driven by a trio of conditions: HIV, hypertension, and obesity. Understanding the multimorbidity burden associated with early adulthood exposures, including potential protective factors (i.e., migration coupled with education), is a critical first step towards improving secondary and tertiary prevention for chronic disease among highly mobile marginalised sub-populations.

Summary: Current understanding of lipid genetics has come mainly from studies in European-ancestry populations; limited effort has focused on Polynesian populations, whose unique population history and high prevalence of dyslipidemia may provide insight into the biological foundations of variation in lipid levels. Here, we performed an association study to fine map a suggestive association on 5q35 with high-density lipoprotein cholesterol (HDL-C) seen in Micronesian and Polynesian populations. Fine-mapping analyses in a cohort of 2,851 Samoan adults highlighted an association between a stop-gain variant (rs200884524; c.652C>T, p.R218∗; posterior probability = 0.9987) in BTNL9 and both lower HDL-C and greater triglycerides (TGs). Meta-analysis across this and several other cohorts of Polynesian ancestry from Samoa, American Samoa, and Aotearoa New Zealand confirmed the presence of this association (βHDL-C = −1.60 mg/dL, pHDL-C = 7.63 × 10−10; βTG = 12.00 mg/dL, pTG = 3.82 × 10−7). While this variant appears to be Polynesian specific, there is also evidence of association from other multiancestry analyses in this region. This work provides evidence of a previously unexplored contributor to the genetic architecture of lipid levels and underscores the importance of genetic analyses in understudied populations.

ABSTRACT: Objective: To describe daytime sleepiness and insomnia among adults in Samoa and identify modifiable factors associated with these measures. Design/setting: Cross-sectional analysis of data from the Soifua Manuia (“Good Health”) study (n = 519, 55.1% female); Upolu island, Samoa. Methods: Daytime sleepiness and insomnia were assessed with the Epworth Sleepiness Scale (ESS) and the Women's Health Initiative Insomnia Rating Scale (WHIIRS), respectively. Detailed physical, sociodemographic, and behavioral factors were collected. Sleep measures were characterized using multiple linear regression with backwards elimination and a bootstrap stability investigation. Results: Excessive daytime sleepiness (ESS>10) and insomnia (WHIIRS>10) were reported by 20% and 6.3% of the sample, respectively. ESS scores were higher in individuals reporting more physical activity (Estimate=1.88; 95% CI=1.12 to 2.75), higher material wealth (0.18; 0.09 to 0.28), and asthma (2.85; 1.25 to 4.51). ESS scores were lower in individuals residing in periurban versus urban regions (-1.43; -2.39 to -0.41), reporting no work versus day shift work (-2.26; -3.07 to -1.41), and reporting greater perceived stress (-0.14; -0.23 to -0.06). WHIIRS scores were lower in individuals reporting “other” shift work (split/irregular/on-call/rotating) versus day shift work (-1.96; -2.89 to -1.14) and those who perceived their village's wealth to be poor/average versus wealthy (-0.94; -1.50 to -0.34). Conclusions: Participants had a generally higher prevalence of excessive daytime sleepiness, but lower prevalence of insomnia, compared with individuals from high-income countries. Factors associated with sleep health differed compared with prior studies, emphasizing potential cultural/environmental differences and the need for targeted interventions to improve sleep health in this setting.

The influence of X chromosome genetic variation on blood lipids and coronary heart disease (CHD) is not well understood. Here, the authors analyse X chromosome sequencing data across 65,322 multi-ancestry individuals, identifying associations of the Xq23 locus with lipid changes and reduced risk of CHD and diabetes mellitus.

Background Pregnancy dietary intake may be associated with newborn body composition, a predictor of future obesity. In Samoa, an energy-dense diet contributes to an alarming prevalence of adult obesity. Identifying associations between pregnancy nutrition and infant body composition in this setting may guide strategies to mitigate intergenerational transmission of obesity risk. Aim To examine dietary macro- and micronutrient intake of Samoan women during the third trimester of pregnancy and associations with infant body composition. Subjects and methods At 34–41 weeks of gestation, we measured dietary intake from the prior month using a Food Frequency Questionnaire (FFQ). Dual-energy X-ray absorptiometry (DXA) measured infant body composition at 1–14 days. We used multivariable linear regression models accounting for confounders to identify independent effects of nutrient intake on infant body composition. Results After adjusting for maternal body mass index, age, gravidity, infant age, and sex, a respective 0.2 g increase and 0.2 g decrease in infant bone mass was associated with fibre and saturated fat intake. Increased protein intake was associated with 0.02 g decrease in bone mass. Conclusions While maternal dietary intake was not associated with infant adiposity or lean mass, we observed an effect on bone mass whose role in regulating metabolic health is overlooked.

The Samoan population has experienced rapid increases in the prevalence of non-communicable diseases (NCDs) and NCD risk factors over the last 30 years. However, understanding how increased awareness and treatment of these conditions in reducing disease burden remains understudied. Using data from a longitudinal study (2010–2019) of cardiometabolic health among Samoan adults, we assess the impact of a referral for elevated blood pressure (BP) on changes in BP, physician’s diagnoses of hypertension and medication use, body mass index (BMI), and other risk factors for elevated BP. Analyses compared adult Samoans (n = 328) who in 2010 either (1) received a referral for elevated BP (BP ≥ 140/90 mmHg) or (2) had measured BP indicative of pre-hypertension (BP ≥ 120/80 mmHg) but were not referred. Data were analysed using linear and logistic regression, paired T- and McNemar’s tests, and Wilcoxon Rank Sum assessments. Referrals in 2010 significantly increased the odds of reporting a physician’s diagnosis of hypertension (OR 2.16; 1.18, 3.95) and hypertension medication use (OR 3.52; 1.86, 6.73) in 2018; however, referrals, medication use, and diagnoses were not associated with BP values or reduced odds of having elevated BP. Despite the referral having positive effects on hypertension-related health care, our results demonstrate that other factors are influencing effective BP/hypertension control. We advocate for greater engagement of health researchers with local health sector actors to improve the probability that researcher-provided health referrals will result in long-term health improvements.

Abstract Background Although the baby-friendly community initiative (BFCI) has been proposed as a community-level approach to improve infant feeding practices, there is little data on its variation in effectiveness by HIV status. We conducted a study to determine the effectiveness of BFCI in changing knowledge and attitudes towards exclusive breastfeeding (EBF) and increasing the rates among HIV negative and HIV positive women in rural Kenya. Methods A community-based cluster-randomized controlled trial was implemented from April 2015 to December 2016 among 901 women enrolled across 13 clusters. The intervention groups received a minimum of 12 personalized home-based counselling sessions on infant feeding by trained community health volunteers from their first or second trimester of pregnancy until 6 months postpartum. Other interventions included education sessions at maternal child clinics, mother-to-mother support group meetings and bi-monthly baby-friendly gatherings targeting influencers. The control group received standard health education at the facility and during monthly routine home visits by community health volunteers not trained on BFCI. Primary outcome measures were the rates of EBF at week 1, months 2, 4 and 6 postpartum. Secondary outcomes included knowledge and attitudes regarding breastfeeding for HIV-exposed infants. Statistical methods included analysis of covariance and logistic regression. Results At 6 months, EBF rates among HIV negative mothers were significantly higher in the BFCI intervention arm compared to the control arm (81.7% versus 42.2% p = 0.001). HIV positive mothers in the intervention arm had higher EBF rates at 6 months than the control but the difference was not statistically significant (81.8% versus 58.4%; p = 0.504). In HIV negative group, there was greater knowledge regarding EBF for HIV-exposed infants in the intervention arm than in the control (92.1% versus 60.7% p = 0.001). Among HIV positive mothers, such knowledge was high among both the intervention and control groups (96% versus 100%, p > 0.1). HIV negative and positive mothers in the intervention arm had more favourable attitudes regarding EBF for HIV-exposed infants than the control (84.5% versus 62.1%, p = 0.001) and (94.6% versus 53.8% to p = 0.001) respectively. Conclusions BFCI interventions can complement facility-based interventions to improve exclusive and continued breastfeeding knowledge, attitudes, and behaviours among HIV negative and positive women.

Summary: Background: Samoa is a Pacific Island country facing one of the highest burdens of non-communicable disease globally. Methods: In this study, we apply a cascade-of-care approach to understand gaps in the awareness, treatment, and control cascade of diabetes and hypertension in a cross-sectional, convenience sample of 703 young, high-risk Samoan adults (29.5-50.9 years). Findings: Non-communicable diseases were prevalent in the study sample: 19.5% (95% CI: 16.6%-22.7%) of participants had diabetes; 47.6% (95% CI: 43.7%-51.4%) presented with pre-diabetes or diabetes; 31.0% (95% CI: 27.5%-34.6%) had hypertension; and nearly 90% (95% CI: 86.7%-91.5%) had overweight or obesity. Among those with diabetes and hypertension, only 20.5% (95% CI: 13.9%-28.4%) and 11.8% (95% CI: 7.8%-16.9%) of participants were aware of their condition, respectively. Only 0.8% (95% CI: 0.0%-4.2%) of all participants with diabetes had achieved glycemic control; only 2.8% (95% CI: 1.1%-6.1%) of those with hypertension achieved control. Interpretation: We found a significant burden of diabetes and hypertension in Samoa, exceeding the recent prevalence estimates of other low- to middle-income countries by nearly two-fold. A severe unmet need in both detection and subsequent control and monitoring of these chronic conditions exists. Our results suggest that the initial diagnosis and surveillance stage in the cascade of care for chronic conditions should be a major focus of primary care efforts; national screening campaigns and programs that leverage village and district nurses to deliver community-based primary care may significantly impact gap closure in the NCD cascade. Funding: This study was supported by the U.S. National Institutes of Health R01HL140570 (PIs: McGarvey and DeLany); AR was supported by NIH FIC D43TW010540; HK and AR-C were supported by the Minority Health and Health Disparities International Research Training (MHIRT) Program at Brown University, NIH Grant # 5T37MD008655.

Summary: Genetic studies on telomere length are important for understanding age-related diseases. Prior GWASs for leukocyte TL have been limited to European and Asian populations. Here, we report the first sequencing-based association study for TL across ancestrally diverse individuals (European, African, Asian, and Hispanic/Latino) from the NHLBI Trans-Omics for Precision Medicine (TOPMed) program. We used whole-genome sequencing (WGS) of whole blood for variant genotype calling and the bioinformatic estimation of telomere length in n = 109,122 individuals. We identified 59 sentinel variants (p < 5 × 10−9) in 36 loci associated with telomere length, including 20 newly associated loci (13 were replicated in external datasets). There was little evidence of effect size heterogeneity across populations. Fine-mapping at OBFC1 indicated that the independent signals colocalized with cell-type-specific eQTLs for OBFC1 (STN1). Using a multi-variant gene-based approach, we identified two genes newly implicated in telomere length, DCLRE1B (SNM1B) and PARN. In PheWAS, we demonstrated that our TL polygenic trait scores (PTSs) were associated with an increased risk of cancer-related phenotypes.

Abstract The baby‐friendly hospital initiative (BFHI) promotes exclusive breastfeeding (EBF) in hospitals, but this is not accessible in rural settings where mothers give birth at home, hence the need for a community intervention. We tested the effectiveness of the baby‐friendly community initiative (BFCI) on EBF in rural Kenya. This cluster randomized study was conducted in 13 community units in Koibatek sub‐county. Pregnant women aged 15–49 years were recruited and followed up until their children were 6 months old. Mothers in the intervention group received standard maternal, infant and young child nutrition counselling, support from trained community health volunteers, health professionals and community and mother support groups, whereas those in the control group received standard counselling only. Data on breastfeeding practices were collected longitudinally. The probability of EBF up to 6 months of age and the restricted mean survival time difference were estimated. A total of 823 (intervention group n = 351) pregnant women were recruited. Compared with children in the control group, children in the intervention group were more likely to exclusively breastfeed for 6 months (79.2% vs. 54.5%; P < .05). Children in the intervention group were also exclusively breastfed for a longer time, mean difference (95% confidence interval [CI]) 0.62 months (0.38, 0.85; P < .001). The BFCI implemented within the existing health system and including community and mother support groups led to a significant increase in EBF in a rural Kenyan setting. This intervention has the potential to improve EBF rates in similar settings.

Abstract Background Type 2 diabetes mellitus (T2DM) is highly prevalent in American Samoa. Community health worker (CHW) interventions may improve T2DM care and be cost-effective. Current cost-effectiveness analyses (CEA) of CHW interventions have either overlooked important cost considerations or not been based on randomized clinical trials (RCTs). The Diabetes Care in American Samoa (DCAS) intervention which occurred in 2009–2010 was a cluster-randomized, culturally tailored, home-visiting CHW intervention and improved HbA1c levels. Objective To analyze the cost-effectiveness of the DCAS intervention against standard care using a RCT in a low-resource setting. Methods We collected clinical, utilization, and cost data over 2 years and modeled quality-adjusted life years (QALYs) gained based on the RCT glycated hemoglobin (HbA1c) improvements. We calculated an incremental cost-effectiveness ratio (ICER) from the societal perspective over a 2-year time horizon and reported all costs in 2012 USD ($). Results Two hundred sixty-eight American Samoans diagnosed with T2DM were cluster randomized into the CHW (n = 104) or standard care control (n = 164) arms. The CHW arm had a mean reduction of 0.53% in HbA1c, an increase of $594 in cost, and an increase of 0.05 QALYs. The ICER for the CHW arm compared to the control arm was $1121 per percentage point HbA1c reduced and $13 191 per QALY gained. Conclusions Compared to a variety of willingness-to-pay thresholds from $39 000 to $154 353 per QALY gained, this ICER shows that the CHW intervention is highly cost-effective. Future studies of the cost-effectiveness of CHW T2DM interventions in similar settings should model lifetime costs and QALYs gained to better assess long-term cost-effectiveness. Trial registration ClinicalTrials.gov, ID NCT00850824. Registered 9 February 2009, https://clinicaltrials.gov/ct2/show/NCT00850824.

Background. The dual burden of cardiovascular diseases and Human Immunodeficiency Virus (HIV) in sub-Saharan Africa is of public health concern. Persons living with HIV are 1.5–2 times more likely to develop CVD risk factors compared to the noninfected individuals. Hypertension is a major risk factor leading to the rising CVD epidemic in SSA. However, the burden of hypertension among HIV patients in Kenya is not well documented. Objective. This study determined the prevalence and the associated factors of hypertension among HIV patients receiving regular care at Thika Level 5 Hospital Comprehensive Care Clinic (CCC), within metropolitan Nairobi, Kenya. Methods. The current cross-sectional study involved review of patients’ records/charts. Charts for adult patients seen in the last 6 months at Thika Level 5 Hospital CCC were included in the study. Hypertension was defined as systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg on two different readings one month apart, while overweight/obesity was defined as body mass index (BMI) ≥ 25 kg/m2. Results. In a sample of 939 HIV patients, the majority, 68.8% (646), were female. The patients’ ages ranged from 18 to 84 years with a median age of 44 (IQR 37–51) years. The mean BMI was higher for females (25.8 kg/m2) compared to that of males (23.1 kg/m2). However, the prevalence of hypertension was higher among males (25.3%) compared to females (16.9%). Age >40 years (AOR = 2.80, p≤0.001), male sex (AOR = 2.10; p=0.04), history of alcohol consumption (AOR = 2.56, p≤0.001), and being overweight/obese (AOR = 2.77 p≤0.001) were significantly associated with hypertension. The antiretroviral (ARV) regimen and, additionally, the duration of antiretroviral therapy had no association with being hypertensive. Conclusion. The prevalence of hypertension is high among HIV patients. Traditional cardiovascular risk factors were associated with hypertension, but no association was observed with ART regime or duration of ARV use. There is a need to integrate hypertension management into regular HIV care.

In low- and middle-income countries, earlier in economic development, obesity tends to be more prevalent in high socioeconomic resource groups compared to low. Later in development, the distribution of obesity tends to show the opposite pattern, becoming more prevalent in those with low socioeconomic resources. This shift in obesity prevalence tends to occur between a gross national income per capita (GNI) of US$1,000 to $4,000 dollars. Whether a similar pattern occurs in Pacific Island countries has not been well documented. In Samoa, the GNI rose to US$3,200 dollars in 2010 at which time over 80% of adults were overweight or obese. We aimed to understand the association of socioeconomic resources, assessed by household assets, with adult body mass index (BMI) and abdominal circumference (AC) in Samoa. Data were from a genome-wide association study for obesity among 3,370 Samoans aged 24.5-

Abstract Background To analyse trends over the period 1991–2013 in systolic blood pressure (SBP), diastolic blood pressure (DBP) and the prevalence of hypertension in adults aged 25–64 years in Samoa; and to assess the contribution of rising obesity levels to period trends. Methods Unit record data from seven population-based surveys (n = 10,881) conducted between 1991 and 2013 were included for analysis. Surveys were adjusted to the nearest previous census to improve national representativeness. Hypertension was defined as SBP ≥140 mmHg and/or DBP ≥90 mmHg and/or on medication for hypertension. Obesity was measured by body mass index (BMI). Poisson, linear and meta-regression were used to assess period trends. Results Over 1991–2013 mean SBP and DBP (mmHg), and the prevalence of hypertension (%) increased in both sexes. Increases in hypertension were: from 18.3 to 33.9% (p

Abstract Background Exclusive breastfeeding (EBF) improves infant health and survival. We tested the effectiveness of a home-based intervention using Community Health Workers (CHWs) on EBF for six months in urban poor settings in Kenya. Methods We conducted a cluster-randomized controlled trial in Korogocho and Viwandani slums in Nairobi. We recruited pregnant women and followed them until the infant’s first birthday. Fourteen community clusters were randomized to intervention or control arm. The intervention arm received home-based nutritional counselling during scheduled visits by CHWs trained to provide specific maternal infant and young child nutrition (MIYCN) messages and standard care. The control arm was visited by CHWs who were not trained in MIYCN and they provided standard care (which included aspects of ante-natal and post-natal care, family planning, water, sanitation and hygiene, delivery with skilled attendance, immunization and community nutrition). CHWs in both groups distributed similar information materials on MIYCN. Differences in EBF by intervention status were tested using chi square and logistic regression, employing intention-to-treat analysis. Results A total of 1110 mother-child pairs were involved, about half in each arm. At baseline, demographic and socioeconomic factors were similar between the two arms. The rates of EBF for 6 months increased from 2% pre-intervention to 55.2% (95% CI 50.4–59.9) in the intervention group and 54.6% (95% CI 50.0–59.1) in the control group. The adjusted odds of EBF (after adjusting for baseline characteristics) were slightly higher in the intervention arm compared to the control arm but not significantly different: for 0–2 months (OR 1.27, 95% CI 0.55 to 2.96; p = 0.550); 0–4 months (OR 1.15; 95% CI 0.54 to 2.42; p = 0.696), and 0–6 months (OR 1.11, 95% CI 0.61 to 2.02; p = 0.718). Conclusions EBF for six months significantly increased in both arms indicating potential effectiveness of using CHWs to provide home-based counselling to mothers. The lack of any difference in EBF rates in the two groups suggests potential contamination of the control arm by information reserved for the intervention arm. Nevertheless, this study indicates a great potential for use of CHWs when they are incentivized and monitored as an effective model of promotion of EBF, particularly in urban poor settings. Given the equivalence of the results in both arms, the study suggests that the basic nutritional training given to CHWs in the basic primary health care training, and/or provision of information materials may be adequate in improving EBF rates in communities. However, further investigations on this may be needed. One contribution of these findings to implementation science is the difficulty in finding an appropriate counterfactual for community-based educational interventions. Trial registration ISRCTN ISRCTN83692672 . Registered 11 November 2012. Retrospectively registered.

Abstract Background Pregnant women in American Samoa have a high risk of complications due to overweight and obesity. Prenatal care can mitigate the risk, however many women do not seek adequate care during pregnancy. Low utilization of prenatal care may stem from low levels of satisfaction with services offered. Our objective was to identify predictors of prenatal care satisfaction in American Samoa. Methods A structured survey was distributed to 165 pregnant women receiving prenatal care at the Lyndon B Johnson Tropical Medical Center, Pago Pago. Women self-reported demographic characteristics, pregnancy history, and satisfaction with prenatal care. Domains of satisfaction were extracted using principal components analysis. Scores were summed across each domain. Linear regression was used to examine associations between maternal characteristics and the summed scores within individual domains and for overall satisfaction. Result Three domains of satisfaction were identified: satisfaction with clinic services, clinic accessibility, and physician interactions. Waiting ≥ 2 h to see the doctor negatively impacted satisfaction with clinic services, clinic accessibility, and overall satisfaction. Living > 20 min from the clinic was associated with lower clinic accessibility, physician interactions, and overall satisfaction. Women who were employed/on maternity leave had lower scores for physician interactions compared with unemployed women/students. Women who did not attend all their appointments had lower overall satisfaction scores. Conclusions Satisfaction with clinic services, clinic accessibility and physician interactions are important contributors to prenatal care satisfaction. To improve patient satisfaction prenatal care clinics should focus on making it easier for women to reach clinics, improving waiting times, and increasing time with providers.

Microbial infections are as old as the hosts they sicken, but interest in the emergence of pathogens and the diseases they cause has been accelerating rapidly. The term ‘emerging infectious disease’ was coined in the mid-1900s to describe changes in disease dynamics in the modern era. Both the term and the phenomena it is meant to characterize have evolved and diversified over time, leading to inconsistencies and confusion. Here, we review the evolution of the term ‘emerging infectious disease’ (EID) in the literature as applied to human hosts. We examine the pathways (e.g., speciation or strain differentiation in the causative agent vs. rapid geographic expansion of an existing pathogen) by which diseases emerge. We propose a new framework for disease and pathogen emergence to improve prioritization. And we illustrate how the operational definition of an EID affects conclusions concerning the pathways by which diseases emerge and the ecological and socioeconomic drivers that elicit emergence. As EIDs appear to be increasing globally, and resources for science level off or decline, the research community is pushed to prioritize its focus on the most threatening diseases, riskiest potential pathogens, and the places they occur. The working definition of emerging infectious diseases and pathogens plays a crucial role in prioritization, but we argue that the current definitions may be impeding these efforts. We propose a new framework for classifying pathogens and diseases as “emerging” that distinguishes EIDs from emerging pathogens and novel potential pathogens. We suggest prioritization of: 1) EIDs for adaptation and mitigation, 2) emerging pathogens for preventive measures, and 3) novel potential pathogens for intensive surveillance.

Background: Migration and urbanization are central to sustainable development and health, but data on temporal trends in defined populations are scarce. Healthy men and women migrate because opportunities for employment and betterment are not equally distributed geographically. The disruption can result in unhealthy exposures and environments and income returns for the origin household. Objectives: The objectives of the paper are to describe the patterns, levels, and trends of temporary migration in rural northeast South Africa; the mortality trends by cause category over the period 2000–2011; and the associations between temporary migration and mortality by broad cause of death categories. Method: Longitudinal, Agincourt Health and Demographic Surveillance System data are used in a continuous, survival time, competing-risk model. Findings: In rural, northeast South Africa, temporary migration, which involves migrants relocating mainly for work purposes and remaining linked to the rural household, is more important than age and sex in explaining variations in mortality, whatever the cause. In this setting, the changing relationship between temporary migration and communicable disease mortality is primarily affected by reduced exposure of the migrant to unhealthy conditions. The study suggests that the changing relationship between temporary migration and non-communicable disease mortality is mainly affected by increased livelihood benefits of longer duration migration. Conclusion: Since temporary migration is not associated with communicable diseases only, public health policies should account for population mobility whatever the targeted health risk. There is a need to strengthen the rural health care system, because migrants tend to return to the rural households when they need health care.

Abnormal lipid levels are important risk factors for cardiovascular diseases. We conducted genome-wide variance component linkage analyses to search for loci influencing total cholesterol (TC), LDL, HDL and triglyceride in families residing in American Samoa and Samoa as well as in a combined sample from the two polities. We adjusted the traits for a number of environmental covariates, such as smoking, alcohol consumption, physical activity, and material lifestyle. We found suggestive univariate linkage with log of the odds (LOD) scores > 3 for LDL on 6p21-p12 (LOD 3.13) in Samoa and on 12q21-q23 (LOD 3.07) in American Samoa. Furthermore, in American Samoa on 12q21, we detected genome-wide linkage (LODeq 3.38) to the bivariate trait TC-LDL. Telomeric of this region, on 12q24, we found suggestive bivariate linkage to TC-HDL (LODeq 3.22) in the combined study sample. In addition, we detected suggestive univariate linkage (LOD 1.9–2.93) on chromosomes 4p-q, 6p, 7q, 9q, 11q, 12q 13q, 15q, 16p, 18q, 19p, 19q and Xq23 and suggestive bivariate linkage (LODeq 2.05–2.62) on chromosomes 6p, 7q, 12p, 12q, and 19p-q. In conclusion, chromosome 6p and 12q may host promising susceptibility loci influencing lipid levels; however, the low degree of overlap between the three study samples strongly encourages further studies of the lipid-related traits.

Background: Batch effects in DNA methylation microarray experiments can lead to spurious results if not properly handled during the plating of samples. Methods: Two pilot studies examining the association of DNA methylation patterns across the genome with obesity in Samoan men were investigated for chip- and row-specific batch effects. For each study, the DNA of 46 obese men and 46 lean men were assayed using Illumina's Infinium HumanMethylation450 BeadChip. In the first study (Sample One), samples from obese and lean subjects were examined on separate chips. In the second study (Sample Two), the samples were balanced on the chips by lean/obese status, age group, and census region. We used methylumi, watermelon, and limma R packages, as well as ComBat, to analyze the data. Principal component analysis and linear regression were respectively employed to identify the top principal components and to test for their association with the batches and lean/obese status. To identify differentially methylated positions (DMPs) between obese and lean males at each locus, we used a moderated t-test.Results: Chip effects were effectively removed from Sample Two but not Sample One. In addition, dramatic differences were observed between the two sets of DMP results. After removing'' batch effects with ComBat, Sample One had 94,191 probes differentially methylated at a q-value threshold of 0.05 while Sample Two had zero differentially methylated probes. The disparate results from Sample One and Sample Two likely arise due to the confounding of lean/obese status with chip and row batch effects.Conclusion: Even the best possible statistical adjustments for batch effects may not completely remove them. Proper study design is vital for guarding against spurious findings due to such effects.

Cysticercosis is a significant public health problem in countries where pigs are raised for consumption and remains an important cause of neurological disease worldwide. The Philippines is considered an endemic area for cysticercosis because cases in both humans and pigs have been reported; however, epidemiologic information stays limited. We conducted a pilot survey of the seroprevalence of human cysticercosis in a village in Leyte, the Philippines, by measuring antibody specific for Taenia solium cyst-fluid antigen. There were 497 subjects aged 7–30 years in our study and most subjects were infected with one or more helminths. The overall cysticercosis seroprevalence in this population was 24.6% (95% CI: 20.82% ~ 28.58%) with no significant difference based on age, sex, or other helminth coinfection status. Although the sample may not be representative of the whole community, the findings suggest that cysticercosis is a significant, but underrecognized public health concern in the Philippines.

IntroductionThe U.S. territory of American Samoa has a disproportionate number of people with type 2 diabetes mellitus compared with neighboring Samoa and the U.S. mainland. The purpose of this research was to study perceptions of diabetes among people with type 2 diabetes in American Samoa in order to design culturally appropriate interventions to prevent and manage diabetes effectively.MethodsSeven focus groups were held with 64 participants at a primary health care facility and a nearby workplace in American Samoa. These focus groups were conducted in the Samoan language and explored perceptions of diabetes, including its meaning, etiology, and the illness experience. Participants were people with diabetes at the health care facility and their family caregivers. ResultsOur systematic analysis of the translated transcripts showed that American Samoans with type 2 diabetes experienced individual, familial, cultural, and environmental stress. They also associated environmental and familial stressors with the worsening of symptoms and increases in blood glucose levels. Although participants believed that stress within the family worsened diabetes symptoms, family members figured prominently as primary caregivers.ConclusionInterventions aimed at improving diabetes management in American Samoa should emphasize family involvement coupled with education and methods to reduce caregiver burden, given the chronic, lifelong nature of diabetes.