Health & Demographic Surveillance System Profile: The Dikgale Health and Demographic Surveillance System

Can verbal autopsies be used on a national scale? Key findings and lessons from South Africa's national cause-of-death validation study

BACKGROUND

Verbal autopsy (VA), though imperfect, serves as a vital tool to determine cause-of-death, particularly for out-of-facility deaths, but challenges persist in integrating VA into Civil Registration and Vital Statistics systems.

OBJECTIVE

To describe the challenges and successes of collecting a national sample of verbal autopsy interviews in South Africa to obtain the cause of death profile in 2017/18.

METHODS

We recruited next of kin from 27 randomly selected sub-districts (10.5%) across South Africa between September 2017 and April 2018. Trained fieldworkers conducted face-to-face interviews using the WHO2016 VA instrument, with physicians certifying underlying causes of death. Feasibility was evaluated based on response rates, participation, and data quality.

RESULTS

Of the total 36,976 deaths registered, only 26% were identified during recruitment, with a 55% overall response rate for VA interviews. Physician-reviewed VA data were deemed of good quality for assigning underlying causes of death in 83% of cases. By comparing cause-specific mortality fractions, physician-reviewed VA identified 22.3% HIV/AIDS and InterVA-5 identified 18.5%, aligning with burden of disease estimates, while Statistics South Africa reported 4.9% HIV/AIDS.

CONCLUSIONS

The study demonstrated the feasibility of using VA on a national scale, but immense challenges in identifying and recruiting next of kin highlight the importance of formalising VAs within the country's death notification system.

Expanding the human gut microbiome atlas of Africa

Population studies are crucial in understanding the complex interplay between the gut microbiome and geographical, lifestyle, genetic, and environmental factors. However, populations from low- and middle-income countries, which represent ~84% of the world population, have been excluded from large-scale gut microbiome research. Here, we present the AWI-Gen 2 Microbiome Project, a cross-sectional gut microbiome study sampling 1,803 women from Burkina Faso, Ghana, Kenya, and South Africa. By intensively engaging with communities that range from rural and horticultural to urban informal settlements and post-industrial, we capture population diversity that represents a far greater breadth of the world's population. Using shotgun metagenomic sequencing, we find that study site explains substantially more microbial variation than disease status. We identify taxa with strong geographic and lifestyle associations, including loss of Treponema and Cryptobacteroides species and gain of Bifidobacterium species in urban populations. We uncover a wealth of prokaryotic and viral novelty, including 1,005 new bacterial metagenome-assembled genomes, and identify phylogeography signatures in Treponema succinifaciens. Finally, we find a microbiome signature of HIV infection that is defined by several taxa not previously associated with HIV, including Dysosmobacter welbionis and Enterocloster sp. This study represents the largest population-representative survey of gut metagenomes of African individuals to date, and paired with extensive clinical biomarkers, demographic data, and lifestyle information, provides extensive opportunity for microbiome-related discovery and research.

A call-to-action: integrate a learning health system framework into longitudinal population studies to improve health response in Africa

Longitudinal population studies (LPSs) in Africa have the potential to become powerful engines of change by adopting a learning health system (LHS) framework. This is a call-to-action opinion and highlights the importance of integrating an LHS approach into LPSs, emphasizing their transformative potential to improve population health response, drive evidence-based decision making, and enhance community well-being. Operators of LPS platforms, community members, government officials, and funding agencies have a role to contribute to this transformative journey of driving evidence-based interventions, promoting health equity, and fostering long-term public health solutions for African communities.

Are multiple coders needed for cause of death assignment: results from telephonic verbal autopsy interviews conducted in 2021 in South Africa

Introduction

Verbal autopsy (VA) methods have emerged to estimate causes of death in populations lacking robust civil registration and vital statistics (CRVS) systems. Despite World Health Organization endorsement of routine VA use, cost and efficiency concerns persist. Telephonic verbal autopsies (teleVAs) can reduce cost. Physician coding offers a valuable approach, but the expertise required makes it resource-intensive, often involving multiple coders for consensus.

Objective

To assess inter-coder agreement for cause of death (CoD) in South African teleVAs using Kappa statistics, evaluating if agreement surpasses a 0.8 cut-off (very high) potentially allowing single coders.

Methods

A cross-sectional study employed telephonic VA interviews on non-facility deaths in Cape Town (December 2020-September 2021). Trained fieldworkers administered a standard VA questionnaire. Each case's VA responses were reviewed independently by two physicians, medically certifying the CoD. A panel was used to solve disagreements. Cohen's kappa-statistic (k-statistic) tested agreement levels.

Results

Decedents were aged between 18 and 98 years. In total, 228 teleVAs (16.6% response rate) were conducted. Physician coding agreement was good overall (k-statistic: 0.63). Diabetes mellitus (47%) and other non-communicable disease (42%) had initial agreement between physician coders in less than 50% of cases in comparison to consensus totals. COVID-19 (89%) and acute cardiac disease (83%) showed initial agreement in more than 80% of cases compared to consensus totals. A chi-square test revealed a significant difference in the number of causes listed on death notification forms for cases with and without agreement in Part 1 (χ2 = 14.71, p < 0.01), but not in Part 2 (χ2 = 4.97, p = 0.17).

Conclusion

CoD agreement might not be high enough to infer that single coders can be used instead of multiple coders. Challenges with co-morbidities and specific CoDs with multiple sequelae highlight the need for further research and refinement of VA methodologies for reliable CoD determination in routine practice.

Seven-day, free-living, objectively-measured ambulatory activity: a data set from the Dikgale Health and Demographic Surveillance System site, Limpopo Province, South Africa

OBJECTIVES

To investigate first, the level, distribution, patterns and prevalence of seven-day, objectively-measured physical activity (ambulation) in a rural health and demographic surveillance system (HDSS) site in South Africa, across demographic, temporal and anthropometric measures, within a sample of adolescent and adult participants from a defined ethnic group. Second, to investigate the strength and direction of association between levels of adiposity and physical activity (ambulation).

DATA DESCRIPTION

The data collected comprises anonymized, individual-level, seven-day pedometry data from a cross-sectional, conveniently sampled survey conducted in 2005-2007. The data includes daily steps and daily activity energy expenditure, basic demographic and temporal information (age, sex, village, day, season) and anthropometric measures (stature, body mass, waist and hip circumference, skinfold thickness) and resting heart rate and blood pressure. Given that this data set was of the first large-scale surveys of objectively-measured physical activity in a South African sample, it could be useful for inclusion in future ecological studies investigating the trend of physical activity over time in the South African population. In addition, this objectively-measured data could provide a useful triangulation point for the interpretation and validation of surveys conducted using self-report measures, especially within rural communities.

Physical Activity and Its Association With Body Mass Index: A Cross-Sectional Analysis in Middle-Aged Adults From 4 Sub-Saharan African Countries

BACKGROUND

This study aimed to explore association of self-reported physical activity domains of work, leisure, and transport-related physical activity and body mass index (BMI) in 9388 adult men and women from the Africa-Wits-INDEPTH partnership for Genomic (AWI-Gen) study in Africa. Africa-Wits-INDEPTH partnership for Genomic is a large, population-based cross-sectional cohort with participants from 6 sites from rural and urban areas in 4 sub-Saharan African countries.

METHODS

A sex-stratified meta-analysis of cross-sectional data from men and women aged 29-82 years was used to assess the association of physical activity with BMI.

RESULTS

Overall, meeting physical activity guidelines of at least 150 minutes per week was associated with 0.82 kg/m2 lower BMI in men (β = -0.80 kg/m2; 95% confidence interval [CI], -1.14 to -0.47) and 0.68 kg/m2 lower BMI in women (β = -0.68 kg/m2; 95% CI, -1.03 to -0.33). Sex and site-specific differences were observed in the associations between physical activity domains and BMI. Among those who met physical activity guidelines, there was an inverse association between transport-related physical activity and BMI in men from Nanoro (Burkina Faso) (β = -0.79 kg/m2; 95% CI, -1.25 to -0.33) as well as work-related physical activity and BMI in Navrongo men (Ghana) (β = -0.76 kg/m2; 95% CI, -1.25 to -0.27) and Nanoro women (β = -0.90 kg/m2; 95% CI, -1.44 to -0.36).

CONCLUSIONS

Physical activity may be an effective strategy to curb rising obesity in Africa. More studies are needed to assess the impact of sex and geographic location-specific physical activity interventions on obesity.

The Multidimension of Malnutrition among School Children in a Rural Area, South Africa: A Mixed Methods Approach

To address childhood malnutrition, the use of multifaceted methodologies, such as mixed methods research, is required to inform effective and contextual interventions. However, this remains limited in studying malnutrition among school children in a South African context, notwithstanding its persistence. We adopted a convergent parallel mixed methods design to best understand the magnitude of malnutrition through multilevel influences in a rural area. A quantitative survey determined the magnitude of malnutrition and associated factors among school children and their mothers (n = 508), parallel to a qualitative study, which explored mothers' insights into the influences of child growth and nutrition in interviews using seven focus group discussions. Mixed methods integration was achieved through convergence of the quantitative constructs developed from measured variables for malnutrition and related factors with ten emergent qualitative themes using a joint display analysis to compare the findings and generate meta-inferences. Qualitative themes on food unavailability and affordability, poor feeding beliefs and practices, and decision to purchase foods were consistent with the quantified poor socio-demographic status of mothers. Furthermore, the qualitative data explained the high prevalence of undernutrition among children but did not corroborate the high estimated households' food security in the quantitative survey. The misperceptions of mothers on child growth agreed with limited food knowledge as well as lack of knowledge on child growth gathered during the survey. Moreover, mothers believed that their children were growing well despite the high presence of childhood undernutrition. Mothers further overrated the effectiveness of school feeding programmes in providing healthy food to children as compared to their household food. They reported high incidence of food allergies, diarrhea, and vomiting caused by food consumed at school which resulted in children not eating certain foods. This might have impacted on the nutritional status of children since mothers depended on the school feeding program to provide food for their children. The ambiguity of cultural influences in relation to child growth was evident and substantiated during qualitative interview. Mixed methods integration offered a better understanding of malnutrition from empirical findings on interrelated factors at child, maternal, household, and school levels. This study points to a need for multilevel, informed, and contextual multidimensional interventions to contribute towards addressing childhood malnutrition in South Africa.

Prevalence of COVID-19 Vaccine Hesitancy in a Rural Setting: A Case Study of DIMAMO Health and Demographic Surveillance Site, Limpopo Province of South Africa

Background: The primary purpose of introducing the COVID-19 vaccine was to fight the pandemic. However, the vaccine was not well received worldwide. This challenge has threatened the effective implementation and roll-out of COVID-19 immunization campaigns. The challenge of vaccine hesitancy was reported to be more prevalent in rural areas due to various factors such as cultural beliefs, misinformation, poverty, lack of education, and distrust of vaccines. Yet there seems to be a scarcity of studies determining the prevalence of vaccine hesitancy in deep rural areas of Limpopo. Purpose: The study aimed to explore the prevalence of COVID-19 hesitancy among the rural black population in South Africa. Study Methods: A longitudinal quantitative study was conducted with data from the DIMAMO Health and Demographic Surveillance Site (HDSS) database for 2020 to 2022. A non-probability total sampling technique was used to select the respondents. Trained fieldworkers collected data using an electronic data capture questionnaire. A comparison of categorical variables was performed using Chi-Square in SPSS version 26 and the statistical significance was set at p < 0.05, with a 95% confidence interval to analyze the data. Results: The limited availability of vaccination sites in Limpopo Province, South Africa, was associated with a reduced certainty that the vaccine would be accepted, as reported in the current study. The prevalence of visiting traditional healers was significantly higher in non-vaccinated than vaccinated participants among the rural black population, indicating a different cultural belief among the rural black population that existed before and during the COVID-19 pandemic. Conclusion: The present study findings show diverse factors of concern associated with vaccination hesitancy for COVID-19 among rural black people. Lack of education, gender, not being diagnosed with COVID-19, not being a Christian, visiting traditional healers, vaccine mistrust, unknown side effects, and a lack of confidence in the vaccine itself. Conspiracy theories were factors that impacted vaccine acceptance among black people living in rural areas. The prevalence of visiting traditional healers was significantly higher in non-vaccinated than vaccinated participants. Therefore, the present study findings emphasize the need to collectively integrate and utilize the traditional healers in the South African healthcare system.

Objectively-measured step cadence and walking patterns in a rural African setting: a cross-sectional analysis

Objectives

To investigate free-living, accelerometry-derived step cadence and walking strategy parameters in 263 adult women (19–56 years) within a rural African setting. Participants were categorised into weight groups: Under-to-Normal Weight (UW/NW: < 25 kg/m²), Overweight-to-Obese (OW/OB: ≥ 25 kg/m²). From the minute-by-minute uni-axial accelerometry data, outcomes describing physical activity intensity, step volume, step cadence and step bouts were extracted. In addition, walking pattern parameters for step bout length and step cadence were determined.

Results

Average step volume was 13,568 steps/day, and > 85% of participants were classified as active-to-highly-active. Overall, ≈ 45% of daily steps was accumulated in the low-to-moderate intensity range. Peak cadence indices were higher in the UW/NW group (p ≤ 0.0112). For both groups, 75% of steps were accumulated in bouts > 15 min, and 95% of bouts were accumulated at 1–39 steps/min. The UW/NW group employed a more varied step cadence, and higher cadences contributed more to step accumulation than the OW/OB group (p ≤ 0.05). There were no significant group differences in bout length strategy parameters (p ≥ 0.0861). Despite no difference between the weight groups in step volume, there were differences in some step cadence indices which reflect higher step intensities, and in cadence strategies chosen to accumulate steps.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-022-06045-9.

Objectively-measured sleep patterns and cardiometabolic health in a rural South African setting: a cross sectional analysis

Background

To investigate the relationship between objectively-measured, free-living sleep patterns, and cardiometabolic health, in a rural South African health and demographic surveillance site.

Methods

Wrist-mounted actigraphy data was collected over nine days from 167 adults (≥ 40 years). Sleep patterns were constructed from tertiles of sleep quantity and quality parameters (TST: total sleep time, AC: activity counts during sleep) from valid minute-by-minute data. The reference category was Moderate TST/Low-to-Moderate AC. Self-reported data included behavioural, health and socio-demographic variables. Biological data included anthropometry, resting blood pressure and fasting blood glucose, insulin and lipids. Binary and ordinal logistic regression models were constructed to determine the association between TST and AC, the factors associated with sleeping patterns, and the association between sleeping patterns and Insulin resistance (HOMA-IR) and Metabolic Syndrome (MetS). HOMA-IR and MetS were also examined across sleep patterns using analysis of variance models.

Results

A total of 139 adults (71.2% female) had a complete dataset. In unadjusted analyses, females had poorer sleep quality, were more physically active, and displayed poorer cardiometabolc health and greater adiposity than males (p ≤ 0.017). There were no sex differences in TST or sleep pattern distribution (p ≤ 0.901). Not being classified as Low TST/High AC or exposed to ≥ 1 bout of Low TST/High AC sleep was associated with lower physical activity, longer sleep duration, better sleep quality and lower IR (p ≤ 0.0452). In multivariate analyses, there was no association between TST and AC (p = 0.921), while increasing age and people-to-bedroom density, and lower physical activity where significantly associated with increasing TST (p ≤ 0.027). Participants classified as Low TST/High AC had significantly higher HOMA-IR, but not MetS, compared with Moderate TST/Low AC (p = 0.021). Being exposed to ≥ 1 bout of Low TST/High AC sleep was significantly associated with hypertension (OR = 2.31, 95%CI: 1.00, 5.34), but not for HOMA-IR or MetS (p ≥ 0.227).

Conclusions

Long sleep was not associated with increased sleep fragmentation. Short, fragmented sleep was associated with insulin resistance. Exposure to at least one bout of short, fragmented sleep increased the likelihood of hypertension. Further studies are required to identify the factors associated with short, fragmented sleep in this setting.

Genetic associations with carotid intima-media thickness link to atherosclerosis with sex-specific effects in sub-Saharan Africans

Atherosclerosis precedes the onset of clinical manifestations of cardiovascular diseases (CVDs). We used carotid intima-media thickness (cIMT) to investigate genetic susceptibility to atherosclerosis in 7894 unrelated adults (3963 women, 3931 men; 40 to 60 years) resident in four sub-Saharan African countries. cIMT was measured by ultrasound and genotyping was performed on the H3Africa SNP Array. Two new African-specific genome-wide significant loci for mean-max cIMT, SIRPA (p = 4.7E-08), and FBXL17 (p = 2.5E-08), were identified. Sex-stratified analysis revealed associations with one male-specific locus, SNX29 (p = 6.3E-09), and two female-specific loci, LARP6 (p = 2.4E-09) and PROK1 (p = 1.0E-08). We replicate previous cIMT associations with different lead SNPs in linkage disequilibrium with SNPs primarily identified in European populations. Our study find significant enrichment for genes involved in oestrogen response from female-specific signals. The genes identified show biological relevance to atherosclerosis and/or CVDs, sex-differences and transferability of signals from non-African studies.

Health and demographic surveillance systems in low- and middle-income countries: history, state of the art and future prospects

Health and Demographic Surveillance Systems (HDSS) have been developed in several low- and middle-income countries (LMICs) in Africa and Asia. This paper reviews their history, state of the art and future potential and highlights substantial areas of contribution by the late Professor Peter Byass.Historically, HDSS appeared in the second half of the twentieth century, responding to a dearth of accurate population data in poorly resourced settings to contextualise the study of interventions to improve health and well-being. The progress of the development of this network is described starting with Pholela, and progressing through Gwembe, Balabgarh, Niakhar, Matlab, Navrongo, Agincourt, Farafenni, and Butajira, and the emergence of the INDEPTH Network in the early 1990'sThe paper describes the HDSS methodology, data, strengths, and limitations. The strengths are particularly their temporal coverage, detail, dense linkage, and the fact that they exist in chronically under-documented populations in LMICs where HDSS sites operate. The main limitations are generalisability to a national population and a potential Hawthorne effect, whereby the project itself may have changed characteristics of the population.The future will include advances in HDSS data harmonisation, accessibility, and protection. Key applications of the data are to validate and assess bias in other datasets. A strong collaboration between a national HDSS network and the national statistics office is modelled in South Africa and Sierra Leone, and it is possible that other low- to middle-income countries will see the benefit and take this approach.

Pregnancy Surveillance Methods within Health and Demographic Surveillance Systems

Background: Pregnancy identification and follow-up surveillance can enhance the reporting of pregnancy outcomes, including stillbirths and perinatal and early postnatal mortality. This paper reviews pregnancy surveillance methods used in Health and Demographic Surveillance Systems (HDSSs) in low- and middle-income countries. Methods: We searched articles containing information about pregnancy identification methods used in HDSSs published between January 2002 and October 2019 using PubMed and Google Scholar. A total of 37 articles were included through literature review and 22 additional articles were identified via manual search of references. We reviewed the gray literature, including websites, online reports, data collection instruments, and HDSS protocols from the Child Health and Mortality Prevention Study (CHAMPS) Network and the International Network for the Demographic Evaluation of Populations and Their Health (INDEPTH). In total, we reviewed information from 52 HDSSs described in 67 sources. Results: Substantial variability exists in pregnancy surveillance approaches across the 52 HDSSs, and surveillance methods are not always clearly documented. 42% of HDSSs applied restrictions based on residency duration to identify who should be included in surveillance. Most commonly, eligible individuals resided in the demographic surveillance area (DSA) for at least three months. 44% of the HDSSs restricted eligibility for pregnancy surveillance based on a woman's age, with most only monitoring women 15-49 years. 10% had eligibility criteria based on marital status, while 11% explicitly included unmarried women in pregnancy surveillance. 38% allowed proxy respondents to answer questions about a woman's pregnancy status in her absence. 20% of HDSSs supplemented pregnancy surveillance with investigations by community health workers or key informants and by linking HDSS data with data from antenatal clinics. Conclusions: Methodological guidelines for conducting pregnancy surveillance should be clearly documented and meticulously implemented, as they can have implications for data quality and accurately informing maternal and child health programs.

The Chronic Kidney Disease in Africa (CKD-Africa) collaboration: lessons from a new pan-African network

Chronic kidney disease (CKD) is a global public health problem, seemingly affecting individuals from low-income and-middle-income countries (LMICs) disproportionately, especially in sub-Saharan Africa. Despite the growing evidence pointing to an increasing prevalence of CKD across Africa, there has not been an Africa-wide concerted effort to provide reliable estimates that could adequately inform health services planning and policy development to address the consequences of CKD. Therefore, we established the CKD in Africa (CKD-Africa) Collaboration. To date, the network has curated data from 39 studies conducted in 12 African countries, totalling 35 747 participants, of which most are from sub-Saharan Africa. We are, however, continuously seeking further collaborations with other groups who have suitable data to grow the network. Although many successful research consortia exist, few papers have been published (with none from Africa) detailing the challenges faced and lessons learnt in setting up and managing a research consortium. Drawing on our experience, we describe the steps taken and the key factors required to establish a functional collaborative consortium among researchers in Africa. In addition, we present the challenges we encountered in building our network, how we managed those challenges and the benefit of such a collaboration for Africa. Although the CKD-Africa Collaboration is focused primarily on CKD research, many of the lessons learnt can be applied more widely in public health research in LMICs.

Towards an appropriate ethics framework for Health and Demographic Surveillance Systems (HDSS): learning from issues faced in diverse HDSS in sub-Saharan Africa

Introduction

Health and Demographic Surveillance Systems (HDSS) collect data on births, deaths and migration from relatively small, geographically defined populations primarily in Africa and Asia. HDSS occupy a grey area between research, healthcare and public health practice and it is unclear how ethics guidance that rely on a research-practice distinction apply to HDSS. This topic has received little attention in the literature. In this paper, based on empirical research across sub-Saharan Africa, we map out key ethical issues for HDSS and assess the relevance of current ethics guidance in relation to these findings.

Methods

We conducted a qualitative study across seven HDSS sites in sub-Saharan Africa, including individual in-depth interviews and informal discussions with 68 research staff, document reviews and non-participant observations of surveillance activities. Qualitative data analysis drew on a framework approach led by a priori and emergent themes, drawing on the wider ethics and social science literature.

Results

There were diverse views on core ethical issues in HDSS, including regarding the strengths and challenges of community engagement, informed consent and data sharing processes. A key emerging issue was unfairness in the overall balance of benefits and burdens for residents and front-line staff when compared with other stakeholders, particularly given the socioeconomic contexts in which HDSS are generally conducted.

Conclusion

We argue that HDSS operate as non-traditional epidemiologic research projects but are often governed using ethics guidance developed for traditional forms of health research. There is a need for specific ethics guidance for HDSS which prioritises considerations around fairness, cost-effectiveness, ancillary care responsibilities, longitudinality and obligations of the global community to HDSS residents.

Estimating the burden of cardiovascular risk in community dwellers over 40 years old in South Africa, Kenya, Burkina Faso and Ghana

Introduction

Cardiovascular disease (CVD) risk factors are increasing in sub-Saharan Africa. The impact of these risk factors on future CVD outcomes and burden is poorly understood. We examined the magnitude of modifiable risk factors, estimated future CVD risk and compared results between three commonly used 10-year CVD risk factor algorithms and their variants in four African countries.

Methods

In the Africa-Wits-INDEPTH partnership for Genomic studies (the AWI-Gen Study), 10 349 randomly sampled individuals aged 40–60 years from six sites participated in a survey, with blood pressure, blood glucose and lipid levels measured. Using these data, 10-year CVD risk estimates using Framingham, Globorisk and WHO-CVD and their office-based variants were generated. Differences in future CVD risk and results by algorithm are described using kappa and coefficients to examine agreement and correlations, respectively.

Results

The 10-year CVD risk across all participants in all sites varied from 2.6% (95% CI: 1.6% to 4.1%) using the WHO-CVD lab algorithm to 6.5% (95% CI: 3.7% to 11.4%) using the Framingham office algorithm, with substantial differences in risk between sites. The highest risk was in South African settings (in urban Soweto: 8.9% (IQR: 5.3–15.3)). Agreement between algorithms was low to moderate (kappa from 0.03 to 0.55) and correlations ranged between 0.28 and 0.70. Depending on the algorithm used, those at high risk (defined as risk of 10-year CVD event >20%) who were under treatment for a modifiable risk factor ranged from 19.2% to 33.9%, with substantial variation by both sex and site.

Conclusion

The African sites in this study are at different stages of an ongoing epidemiological transition as evidenced by both risk factor levels and estimated 10-year CVD risk. There is low correlation and disparate levels of population risk, predicted by different risk algorithms, within sites. Validating existing risk algorithms or designing context-specific 10-year CVD risk algorithms is essential for accurately defining population risk and targeting national policies and individual CVD treatment on the African continent.

Protective Behaviors and Secondary Harms Resulting From Nonpharmaceutical Interventions During the COVID-19 Epidemic in South Africa: Multisite, Prospective Longitudinal Study

BACKGROUND

In March 2020, South Africa implemented strict nonpharmaceutical interventions (NPIs) to contain the spread of COVID-19. Over the subsequent 5 months, NPI policies were eased in stages according to a national strategy. COVID-19 spread throughout the country heterogeneously; the disease reached rural areas by July and case numbers peaked from July to August. A second COVID-19 wave began in late 2020. Data on the impact of NPI policies on social and economic well-being and access to health care are limited.

OBJECTIVE

We aimed to determine how rural residents in three South African provinces changed their behaviors during the first COVID-19 epidemic wave.

METHODS

The South African Population Research Infrastructure Network nodes in the Mpumalanga (Agincourt), KwaZulu-Natal, (Africa Health Research Institute) and Limpopo (Dikgale-Mamabolo-Mothiba) provinces conducted up to 14 rounds of longitudinal telephone surveys among randomly sampled households from rural and periurban surveillance populations every 2-3 weeks. Interviews included questions on the following topics: COVID-19-related knowledge and behaviors, the health and economic impacts of NPIs, and mental health. We analyzed how responses varied based on NPI stringency and household sociodemographics.

RESULTS

In total, 5120 households completed 23,095 interviews between April and December 2020. Respondents' self-reported satisfaction with their COVID-19-related knowledge and face mask use rapidly rose to 85% and 95%, respectively, by August. As selected NPIs were eased, the amount of travel increased, economic losses were reduced, and the prevalence of anxiety and depression symptoms fell. When the number of COVID-19 cases spiked at one node in July, the amount of travel dropped rapidly and the rate of missed daily medications doubled. Households where more adults received government-funded old-age pensions reported concerns about economic matters and medication access less often.

CONCLUSIONS

South Africans complied with stringent, COVID-19-related NPIs despite the threat of substantial social, economic, and health repercussions. Government-supported social welfare programs appeared to buffer interruptions in income and health care access during local outbreaks. Epidemic control policies must be balanced against the broader well-being of people in resource-limited settings and designed with parallel support systems when such policies threaten peoples' income and access to basic services.

Adiposity Phenotypes and Subclinical Atherosclerosis in Adults from Sub-Saharan Africa: An H3Africa AWI-Gen Study

Background:

Obesity and adipose tissue distribution contribute to an increased risk of cardiovascular disease (CVD) by promoting atherosclerosis. This association has been poorly studied in sub–Saharan Africa (SSA) despite the rising prevalence of cardiovascular disease.

Objectives:

We determined the association between various adiposity phenotypes and carotid intima–media thickness (CIMT), a proxy of subclinical atherosclerosis, in a large SSA population.

Methods:

A population–based cross–sectional study was performed from 2013–2016 in Burkina Faso, Ghana, Kenya and South Africa. Body mass index (BMI), waist (WC), hip circumferences (HC), visceral (VAT) and subcutaneous adipose tissue (SCAT) using B-mode ultrasound were measured. Ultrasonography of left and right far wall CIMT of the common carotid artery was used as an indicator of subclinical atherosclerosis. Individual participant data meta–analyses were used to determine the associations between adiposity phenotypes and CIMT in the pooled sample while adjusted multivariable linear regression analyses were used for site specific analyses.

Results:

Data were obtained from 9,010 adults (50.3% women and a mean age of 50± 6years). Men had higher levels of visceral fat than women while women had higher BMI, waist and hip circumference and subcutaneous fat than men at all sites except Burkina Faso. In the pooled analyses, BMI (β–value [95% CIs]: 19.5 [16.8, 22.3] μm) showed the strongest relationship with CIMT followed by VAT (5.86 [4.65, 7.07] μm), SCAT (5.00 [2.85, 7.15] μm), WC (1.27 [1.09, 1.44] μm) and HC (1.23 [1.04, 1.42] μm). Stronger associations were observed in men than in women.

Conclusion:

Obesity within SSA will likely result in higher levels of atherosclerosis and promote the occurrence of cardio- and cerebrovascular events, especially in males, unless addressed through primary prevention of obesity in both rural and urban communities across Africa. The inverse association of VAT with CIMT in Burkina Faso and Ghana requires further investigation.

Highlights

Maternal and neonatal data collection systems in low- and middle-income countries for maternal vaccines active safety surveillance systems: A scoping review

BACKGROUND

Most post-licensure vaccine pharmacovigilance in low- and middle-income countries (LMICs) are passive reporting systems. These have limited utility for maternal immunization pharmacovigilance in LMIC settings and need to be supplemented with active surveillance. Our study's main objective was to identify existing perinatal data collection systems in LMICs that collect individual information on maternal and neonatal health outcomes and could be developed to inform active safety surveillance of novel vaccines for use during pregnancy.

METHODS

A scoping review was performed following the Arksey and O'Malley six-stage approach. We included studies describing electronic or mixed paper-electronic data collection systems in LMICs, including research networks, electronic medical records, and custom software platforms for health information systems. Medline PubMed, EMBASE, Global Health, Cochrane Library, LILACS, Bibliography of Asian Studies (BAS), and CINAHL were searched through August 2019. We also searched grey literature including through Google and websites of existing relevant perinatal data collection systems, as well as contacted authors of key studies and experts in the field to validate the information and identify additional sources of relevant unpublished information.

RESULTS

A total of 11,817 records were identified. The full texts of 264 records describing 96 data collection systems were assessed for eligibility. Eight perinatal data collection systems met our inclusion criteria: Global Network's Maternal Newborn Health Registry, International Network for the Demographic Evaluation of Populations and their Health; Perinatal Informatic System; Pregnancy Exposure Registry & Birth Defects Surveillance; SmartCare; Open Medical Record System; Open Smart Register Platform and District Health Information Software 2. These selected systems were qualitatively characterized according to seven different domains: governance; system design; system management; data management; data sources, outcomes and data quality.

CONCLUSION

This review provides a list of active maternal and neonatal data collection systems in LMICs and their characteristics as well as their outreach, strengths, and limitations. Findings could potentially help further understand where to obtain population-based high-quality information on outcomes to inform the conduct of maternal immunization active vaccine safety surveillance activities and research in LMICs.

Engaging Mothers on the Growth of School-Age Children in a Rural South African Health and Demographic Site: A Qualitative Insight

A qualitative study was conducted to explore mothers' insights on the growth of school-age children in a rural Health and Demographic site of Limpopo Province, in South Africa. The participants were selected using purposive sampling. Data were collected from seven focus group discussions, which were audio-taped and transcribed verbatim. NVivo10 was used to analyse interview transcripts, following qualitative thematic analysis. Fifty-four mothers aged between 27 and 52 years were interviewed. Unfavourable sociodemographic status with poor living conditions of mothers were observed, particularly in terms of unemployment, minimal tertiary education, and rural locality. The perceptions of mothers on child growth linked growth of their children to various factors such as poverty and socioeconomic status, genetic/family heredity, and household environment. Mothers further related child growth to purchasing power and decisions regarding types of food, food unavailability, affordability issues, feeding beliefs and practices; and child food preferences, school feeding schemes, and maternal and societal cultural beliefs and practices. Despite their concerns, mothers perceived that their children were growing well, but differently. It is worth noting that the views of mothers on child growth were up to their aptitude level and might have been restricted due to their level of education and rural locality. Hence, there is a need for novel information, education, and communication strategies to effectively reach mothers, especially in rural areas, regarding the importance of identifying children with growth failure and its prevention. Mothers should be able to identify when a child is affected by growth failure and to seek healthcare, in order to prevent children from progressing to severe forms. This study informs on the timing of nutritional interventions for children and context-specific health promotion and health education programs to improve the knowledge of mothers on child growth.

Association between cardiometabolic health and objectively-measured, free-living sleep parameters: a pilot study in a rural African setting

Objectives

To investigate the relationship between objectively-measured, free-living sleep quantity and quality, and cardiometabolic health, in a rural African setting in 139 adults (≥40 years, female: n = 99, male: n = 40). Wrist-mounted, tri-axial accelerometry data was collected over 9 days. Measures of sleep quantity and quality, and physical activity were extracted from valid minute-by-minute data. Self-reported data included behavioural, health and socio-demographic variables. Biological data included body composition, resting blood pressure and fasting blood glucose, insulin and lipids. Logistic regression models were constructed with insulin resistance (IR) and cardiometabolic (CM) risk, as dependent variables, adjusting for socio-demographic, behavioural and biological factors.

Results

Nocturnal sleep time was longer in females (p = 0.054) and sleep quality was better in males (p ≤ 0.017). Few participants slept > 9 h/night (4–5%), and 46–50% slept < 7 h/night. IR and CM risk was higher in females (p ≤ 0.006). In adjusted models, sleep variables were independently associated with IR (p < 0.05). Sleep quantity was non-linearly associated with CM risk (p ≤ 0.0398), and linearly associated with IR (p ≤ 0.0444). Sleep quality was linearly related with CM risk and IR (p ≤ 0.0201). In several models, sleep quantity and sleep quality measures were concurrently and significantly associated with IR (p ≤ 0.044).

Protective behaviours and secondary harms from non-pharmaceutical interventions during the COVID-19 epidemic in South Africa: a multisite prospective longitudinal study

Background:

In March 2020 South Africa implemented strict non-pharmaceutical interventions (NPIs) to contain Covid-19. Over the subsequent five months NPIs were eased in stages according to national strategy. Covid-19 spread throughout the country heterogeneously, reaching rural areas by July and peaking in July-August. Data on the impact of NPI policies on social and economic wellbeing and access to healthcare is limited. We therefore analysed how rural residents of three South African provinces changed their behaviour during the first epidemic wave.

Methods:

The South African Population Research Infrastructure Network (SAPRIN) nodes in Mpumalanga (Agincourt), KwaZulu-Natal (AHRI) and Limpopo (DIMAMO) provinces conducted longitudinal telephone surveys among randomly sampled households from rural and peri-urban surveillance populations every 2-3 weeks. Interviews included questions on: Covid-19 knowledge and behaviours; health and economic impact of NPIs; and mental health.

Results:

2262 households completed 10,966 interviews between April and August 2020. By August, self-reported satisfaction with Covid-19 knowledge had risen from 48% to 85% and facemask use to over 95%. As selected NPIs were eased mobility increased, and economic losses and anxiety and depression symptoms fell. When Covid-19 cases spiked at one node in July, movement dropped rapidly, and missed daily medication rates doubled. Economic concerns and mental health symptoms were lower in households receiving a greater number of government-funded old-age pensions.

Conclusions:

South Africans reported complying with stringent Covid-19 NPIs despite the threat of substantial social, economic and health repercussions. Government-supported social welfare programmes appeared to buffer interruptions in income and healthcare access during local outbreaks. Epidemic control policies must be balanced against impacts on wellbeing in resource-limited settings and designed with parallel support systems where they threaten income and basic service access.

Protocol: Leveraging a demographic and health surveillance system for Covid-19 Surveillance in rural KwaZulu-Natal

A coordinated system of disease surveillance will be critical to effectively control the coronavirus disease 2019 (Covid-19) pandemic. Such systems enable rapid detection and mapping of epidemics and inform allocation of scarce prevention and intervention resources. Although many lower- and middle-income settings lack infrastructure for optimal disease surveillance, health and demographic surveillance systems (HDSS) provide a unique opportunity for epidemic monitoring. This protocol describes a surveillance program at the Africa Health Research Institute's Population Intervention Platform site in northern KwaZulu-Natal. The program leverages a longstanding HDSS in a rural, resource-limited setting with very high prevalence of HIV and tuberculosis to perform Covid-19 surveillance. Our primary aims include: describing the epidemiology of the Covid-19 epidemic in rural KwaZulu-Natal; determining the impact of the Covid-19 outbreak and non-pharmaceutical control interventions (NPI) on behaviour and wellbeing; determining the impact of HIV and tuberculosis on Covid-19 susceptibility; and using collected data to support the local public-sector health response. The program involves telephone-based interviews with over 20,000 households every four months, plus a sub-study calling 750 households every two weeks. Each call asks a household representative how the epidemic and NPI are affecting the household and conducts a Covid-19 risk screen for all resident members. Any individuals screening positive are invited to a clinical screen, potential test and referral to necessary care - conducted in-person near their home following careful risk minimization procedures. In this protocol we report the details of our cohort design, questionnaires, data and reporting structures, and standard operating procedures in hopes that our project can inform similar efforts elsewhere.

Community engagement in Genomics research; Challenges and lessons learnt in the AWI-Gen study at Dikgale Health and Demographic Surveillance System (HDSS) Site, South Africa

As health research often requires consent from participants and permission from community gate keepers, community engagement is considered an integral process of health research. Community engagement is also important in building trust between the research team and participants, gathering information on the needs and expectations of the community with respect to the project and present the community with an opportunity to gain more information on the goals of the research. Although there are published guidelines on how to conduct community engagement activities, the concept itself and the way in which it is put into practice is highly contextual. In this paper we reflect on the community engagement strategy used in the AWI-Gen Phase 1 study at the Dikgale Health and Demographic Surveillance System (Dikgale HDSS) site, the challenges encountered throughout the research process and the lessons learnt. Lastly, we highlight possible improvements to the CE strategic framework for AWI-Gen Phase 2 in Dikgale HDSS that may enhance the participation of the community.

Descriptive epidemiology of objectively-measured, free-living sleep parameters in a rural African setting

OBJECTIVES

To investigate the descriptive nature of objectively-measured, free-living sleep quantity and quality, and the relationship to adiposity, in a rural African setting in 145 adults (≥ 40 years, female: n = 104, male: n = 41). Wrist-mounted, triaxial accelerometry data was collected over 9 days. Measures of sleep quantity and quality, and physical activity were extracted from valid minute-by-minute data. Adiposity indices were body-mass-index, waist circumference and conicity index. Self-reported data included behavioural, health and socio-demographic variables. Community consultation followed the quantitative data analyses, for validation and interpretation of findings.

RESULTS

Females had more nocturnal sleep than males (7.2 vs. 6.8 h/night, p = 0.0464) while males recorded more diurnal sleep time (p = 0.0290). Wake after sleep onset and number of awakenings were higher in females, and sleep efficiency was higher in males (p ≤ 0.0225). Sleep indices were generally similar between weekdays and weekends, except for sleep fragmentation index (p = 0.0458). Sleep quantity, but not sleep quality was independently and inversely associated with adiposity (p = 0.0453). Physical activity and morbidity measures were significantly and consistently associated with sleep and adiposity measures (p < 0.0458). The preliminary qualitative data suggests that future studies should include more detailed data around contextual issues of sleep (social, cultural, economic, environment).

Protocol: Leveraging a demographic and health surveillance system for Covid-19 Surveillance in rural KwaZulu-Natal

A coordinated system of disease surveillance will be critical to effectively control the coronavirus disease 2019 (Covid-19) pandemic. Such systems enable rapid detection and mapping of epidemics and inform allocation of scarce prevention and intervention resources. Although many lower- and middle-income settings lack infrastructure for optimal disease surveillance, health and demographic surveillance systems (HDSS) provide a unique opportunity for epidemic monitoring. This protocol describes a surveillance program at the Africa Health Research Institute's Population Intervention Platform site in northern KwaZulu-Natal. The program leverages a longstanding HDSS in a rural, resource-limited setting with very high prevalence of HIV and tuberculosis to perform Covid-19 surveillance. Our primary aims include: describing the epidemiology of the Covid-19 epidemic in rural KwaZulu-Natal; determining the impact of the Covid-19 outbreak and non-pharmaceutical control interventions (NPI) on behaviour and wellbeing; determining the impact of HIV and tuberculosis on Covid-19 susceptibility; and using collected data to support the local public-sector health response. The program involves telephone-based interviews with over 20,000 households every four months, plus a sub-study calling 750 households every two weeks. Each call asks a household representative how the epidemic and NPI are affecting the household and conducts a Covid-19 risk screen for all resident members. Any individuals screening positive are invited to a clinical screen, potential test and referral to necessary care - conducted in-person near their home following careful risk minimization procedures. In this protocol we report the details of our cohort design, questionnaires, data and reporting structures, and standard operating procedures in hopes that our project can inform similar efforts elsewhere.

Objectively-measured physical activity patterns and longitudinal weight category status in a rural setting

Objectives

To investigate the relationship between longitudinal weight-change and objectively-measured physical activity (PA) in a rural African setting in 143 adults (≥ 30 years), using data from two cross-sectional surveys, separated by approximately 10 years. Participants were categorised into three weight-change groups (Weight-loss: ≥ 25 kg m⁻²→ < 25 kg m⁻²; Weight-gain: < 25 kg m⁻²→ ≥ 25 kg m⁻²; Weight-stability: remained < 25 kg m⁻² or ≥ 25 kg m⁻²). Daily ambulation and activity energy expenditure (AEE), measured in the 2005–2007 health survey, was examined across the weight-change groups. Using the daily AEE data, the proportion of those in the weight-change groups, meeting or not meeting two PA guidelines (150- and 420 min week⁻¹), was examined.

Results

Weight-change was found in 18.2% of the sample. There was no significant overall body mass change (+ 1.2 kg, p = 0.1616). However, there was significant change in body mass in the weight-gain (+ 15.2 kg) and weight-loss (− 10.8 kg) groups (p ≤ 0.0011). Nearly 90% of those who gained weight met the 150 min week⁻¹ guideline. A significantly greater proportion of the weight-stable group (< 25 kg m⁻²) met the 420 min week⁻¹ guideline (p < 0.05). Ambulatory level was high irrespective of weight group, although the weight-stable group (< 25 kg m⁻²) approached 15,000 steps day⁻¹. There was an inconsistent and weak association between PA and weight-change in this group.

Deriving objectively-measured sedentary indices from free-living accelerometry data in rural and urban African settings: a cost effective approach

Objectives

To investigate the agreement between two data reduction approaches for detecting sedentary breaks from uni-axial accelerometry data collected in human participants. Free-living, uni-axial accelerometer data (n = 318) were examined for sedentary breaks using two different methods (Healy–Matthews; MAH/UFFE). The data were cleaned and reduced using MAH/UFFE Analyzer software and custom Microsoft Excel macro’s, such that the average daily sedentary break number were calculated for each data record, for both methods.

Results

The Healy–Matthews and MAH/UFFE average daily break number correlated closely (R² = 99.9%) and there was high agreement (mean difference: + 0.7 breaks/day; 95% limits of agreement: − 0.06 to + 1.4 breaks/day). A slight bias of approximately + 1 break/day for the MAH/UFFE Analyzer was evident for both the regression and agreement analyses. At a group level there were no statistically or practically significant differences within sample groups between the two methods.

Childhood Undernutrition and Its Predictors in a Rural Health and Demographic Surveillance System Site in South Africa

BACKGROUND

Overweight and obesity are increasing at an alarming rate in South Africa, while childhood undernutrition remains persistently high. This study determined the magnitude and predictors of stunting and underweight among schoolchildren in the Dikgale and Health Demographic Surveillance System Site, a rural site in South Africa.

METHODS

A cross sectional study using multistage sampling was conducted among 508 schoolchildren and their mothers. Anthropometric measurements were taken from children and their mothers, while sociodemographic information was obtained from mothers using a questionnaire. The World Health Organization Anthro Plus was used to generate height-for-age and weight-for-age z-scores to indicate stunting and underweight, respectively, among the children. Maternal overweight and obesity were assessed using body mass index. Bivariate and multivariate logistic regression analyses were used to evaluate the predictors of stunting and underweight among schoolchildren.

RESULTS

Twenty-two percent (22%) of children were stunted and 27% were underweight, while 27.4% of the mothers were overweight and 42.3% were obese. The odds of being stunted were lower in younger children, whereas having a mother who was overweight/obese and had a short stature increased the odds of stunting. Access to water, having a refrigerator, and having a young mother were protective against being underweight. Having a mother who was overweight/obese increased the odds of being underweight.

CONCLUSIONS

The study showed a high prevalence of stunting and underweight among children, and overweight and obesity among mothers, indicating a household double burden of malnutrition. The age of the child and maternal overweight/obesity and short stature were predictors of stunting and underweight, while having a younger mother and access to water and a refrigerator were protective against being underweight. The need for an evidence-based and feasible nutrition program for schoolchildren, especially those in rural schools, cannot be over-emphasized.

The double burden of malnutrition in a rural health and demographic surveillance system site in South Africa: a study of primary schoolchildren and their mothers

BACKGROUND

In South Africa, the occurrence of the double burden of malnutrition is on the rise at a household level predisposing children and their mothers to negative health outcomes. However, few studies have been conducted at a household level. Therefore, we studied a double burden of malnutrition using child-mother pairs in a rural setting.

METHODS

A cross-sectional quantitative survey was conducted among 508 child-mother pairs selected from primary schools using a multistage sampling in a rural Dikgale Health and Demographic Site in Limpopo Province, South Africa. Anthropometric measurements of children and mothers, and socio-demographic data were collected. WHO AnthroPlus was used to generate body-mass-index z-scores of children and the BMI was used to indicate overweight and obesity among the mothers. Mann Whitney test was used to compare the means of variables between sexes and age groups, while the prevalence of thinness and overweight/obesity were compared using a chi-square. Multivariate logistic regression with a stepwise backward elimination procedure, controlling for confounding, was used to determine the association between the thinness and overweight/obesity and the covariates.

RESULTS

Twenty five percent (25%) of the children were thin, 4% were overweight and 1% obese, while mothers were overweight (27.4%) and 42.3% obesity (42.3%) were observed among the mothers. The odds of being thin were higher in boys than in girls (AOR = 1.53, 95%CI: 1.01-2.35). Overweight/obese mothers were more likely to have thin children (AOR = 1.48, 95% CI: 1.01-2.18) and less likely to have overweight/obese children (AOR = 0.18, 95%CI: 0.07-0.46).

CONCLUSION

A double burden of malnutrition was observed on a household level with thinness among children and overweight/obesity among mothers. A need to address the dual problems of undernutrition and rapidly rising trends of overweight/obesity cannot be over-emphasized.

Classical Cardiovascular Risk Factors and HIV are Associated With Carotid Intima-Media Thickness in Adults From Sub-Saharan Africa: Findings From H3Africa AWI-Gen Study

Background Studies on the determinants of carotid intima-media thickness ( CIMT ), a marker of sub-clinical atherosclerosis, mostly come from white, Asian, and diasporan black populations. We present CIMT data from sub-Saharan Africa, which is experiencing a rising burden of cardiovascular diseases and infectious diseases. Methods and Results The H3 (Human Hereditary and Health) in Africa's AWI-Gen (African-Wits-INDEPTH partnership for Genomic) study is a cross-sectional study conducted in adults aged 40 to 60 years from Burkina Faso, Kenya, Ghana, and South Africa. Cardiovascular disease risk and ultrasonography of the CIMT of right and left common carotids were measured. Multivariable linear and mixed-effect multilevel regression modeling was applied to determine factors related to CIMT. Data included 8872 adults (50.8% men), mean age of 50±6 years with age- and sex-adjusted mean (±SE) CIMT of 640±123μm. Participants from Ghana and Burkina Faso had higher CIMT compared with other sites. Age (β = 6.77, 95%CI [6.34-7.19]), body mass index (17.6[12.5-22.8]), systolic blood pressure (7.52[6.21-8.83]), low-density lipoprotein cholesterol (5.08[2.10-8.06]) and men (10.3[4.75- 15.9]) were associated with higher CIMT. Smoking was associated with higher CIMT in men. High-density lipoprotein cholesterol (-12.2 [-17.9- -6.41]), alcohol consumption (-13.5 [-19.1--7.91]) and HIV (-8.86 [-15.7--2.03]) were inversely associated with CIMT. Conclusions Given the rising prevalence of cardiovascular diseases risk factors in sub-Saharan Africa, atherosclerotic diseases may become a major pan-African epidemic unless preventive measures are taken particularly for prevention of hypertension, obesity, and smoking. HIV -specific studies are needed to fully understand the association between HIV and CIMT in sub-Saharan Africa.

Genomic and environmental risk factors for cardiometabolic diseases in Africa: methods used for Phase 1 of the AWI-Gen population cross-sectional study

There is an alarming tide of cardiovascular and metabolic disease (CMD) sweeping across Africa. This may be a result of an increasingly urbanized lifestyle characterized by the growing consumption of processed and calorie-dense food, combined with physical inactivity and more sedentary behaviour. While the link between lifestyle and public health has been extensively studied in Caucasian and African American populations, few studies have been conducted in Africa. This paper describes the detailed methods for Phase 1 of the AWI-Gen study that were used to capture phenotype data and assess the associated risk factors and end points for CMD in persons over the age of 40 years in sub-Saharan Africa (SSA). We developed a population-based cross-sectional study of disease burden and phenotype in Africans, across six centres in SSA. These centres are in West Africa (Nanoro, Burkina Faso, and Navrongo, Ghana), in East Africa (Nairobi, Kenya) and in South Africa (Agincourt, Dikgale and Soweto). A total of 10,702 individuals between the ages of 40 and 60 years were recruited into the study across the six centres, plus an additional 1021 participants over the age of 60 years from the Agincourt centre. We collected socio-demographic, anthropometric, medical history, diet, physical activity, fat distribution and alcohol/tobacco consumption data from participants. Blood samples were collected for disease-related biomarker assays, and genomic DNA extraction for genome-wide association studies. Urine samples were collected to assess kidney function. The study provides base-line data for the development of a series of cohorts with a second wave of data collection in Phase 2 of the study. These data will provide valuable insights into the genetic and environmental influences on CMD on the African continent.

Determinants of body mass index by gender in the Dikgale Health and Demographic Surveillance System site, South Africa

BACKGROUND

The study was conducted in the Dikgale Health and Demographic Surveillance System (DHDSS) site where we have observed increasing obesity levels, particularly in women, despite evidence of high physical activity (PA) and a relatively low daily energy intake.

OBJECTIVE

This study aimed to assess the socio-demographic, behavioural and biological determinants of body mass index (BMI) in adult residents permanently residing in the DHDSS.

METHODS

A cross-sectional study was conducted in which socio-demographic, behavioural and biological characteristics from 1143 participants (aged 40-60 years) were collected using a paper questionnaire and standard anthropometric measures. Human immunodeficiency virus (HIV) testing was performed on all participants except those who indicated that they had tested positive. Chi-square and Mann-Whitney tests were used to analyze categorical and continuous variables, respectively, while hierarchical multivariate regression was used to analyze predictors of BMI.

RESULTS

The median age of women and men was 51 (46-56) and 50 (45-55) years, respectively. The prevalence of overweight-obesity was 76% in women and 21% in men. A significant negative association of BMI with HIV and smoking and a significant positive association with socio-economic status (SES) was observed in both sexes. In women, BMI was negatively associated with sleep duration (p = 0.015) and age (p = 0.012), but positively associated with sugar-sweetened beverages (SSBs) (p = 0.08). In men, BMI was negatively associated with alcohol use (p = 0.016) and positively associated with being married (p < 0.001). PA was not associated with BMI in either sexes. Full models explained 9.2% and 20% of the variance in BMI in women and men, respectively.

CONCLUSION

BMI in DHDSS adults is not associated with physical inactivity but is associated wealth, marital status, sleep, smoking, alcohol use, and HIV status. Future studies should explore the contribution of nutrition, stunting, psycho-social and genetic factors to overweight and obesity in DHDSS.

Regional and Sex Differences in the Prevalence and Awareness of Hypertension: An H3Africa AWI-Gen Study Across 6 Sites in Sub-Saharan Africa

BACKGROUND

There is a high prevalence of hypertension and related cardiovascular diseases in sub-Saharan Africa, yet few large studies exploring hypertension in Africa are available. The actual burden of disease is poorly understood and awareness and treatment to control it is often suboptimal.

OBJECTIVES

The study sought to report the prevalence of measured hypertension and to assess awareness and control of blood pressure among older adults in rural and urban settings in 6 sites located in West, East, and Southern Africa. In addition, we examined regional, sex, and age differences related to hypertension.

METHODS

A population-based cross-sectional study was performed at 6 sites in 4 African countries: Burkina Faso (Nanoro), Ghana (Navrongo), Kenya (Nairobi), and South Africa (Agincourt, Dikgale, Soweto). Blood pressure measurements were taken using standardized procedures on 10,696 adults 40 to 60 years of age. Hypertension was defined as systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg or taking antihypertensive medication.

RESULTS

The mean prevalence of hypertension ranged from 15.1% in Nanoro to 54.1% in Soweto. All 3 of the South African sites had a mean prevalence of hypertension of over 40.0%, significantly higher than in Nairobi (25.6%) and Navrongo (24.5%). Prevalence increased with age in both sexes and at all sites. A significantly higher prevalence of hypertension was observed in women in Agincourt, Dikgale, and Nairobi, whereas in Nanoro this trend was reversed. Within the hypertensive group the average proportion of participants who were aware of their blood pressure status was only 39.4% for men and 53.8% for women, and varied widely across sites.

CONCLUSIONS

Our study demonstrates that the prevalence of hypertension and the level of disease awareness differ not only between but also within sub-Saharan African countries. Each nation must tailor their regional hypertension awareness and screening programs to match the characteristics of their local populations.

Weight status and associated factors among HIV infected people on antiretroviral therapy in rural Dikgale, Limpopo, South Africa

BACKGROUND

Underweight in human immunodeficiency virus (HIV)-infected people on antiretroviral therapy (ART) complicates the management of HIV infection and contributes to mortality, whereas overweight increases the risk of cardiovascular disease (CVD).

AIM

The study determined weight status and associated factors in people with HIV infection receiving ART.

SETTING

Rural primary health care clinics in Dikgale, Limpopo province, South Africa.

METHODS

A cross-sectional study in which data were collected using the World Health Organization (WHO) stepwise approach to surveillance (STEPS) questionnaire and calculated using WHO analysis programmes guide. Weight and height were measured using standard WHO procedures, and body mass index was calculated as weight (kg)/height (m2). Data on ART duration were extracted from patients' files. CD4 lymphocyte counts and viral load were determined using standard laboratory techniques.

RESULTS

Of the 214 participants, 8.9%, 54.7% and 36.4% were underweight, normal weight and overweight, respectively. Physical activity (OR: 0.99, p = 0.001) and male gender (OR: 0.29, p = 0.04) were negatively associated with overweight. Men who used tobacco were more likely to be underweight than non-tobacco users (OR: 10.87, p = 0.02). Neither ART duration nor viral load or CD4 count was independently associated with underweight or overweight in multivariate analysis.

CONCLUSION

A high proportion of people on ART were overweight and a smaller proportion underweight. There is a need to simultaneously address the two extreme weight problems in this vulnerable population through educating them on benefits of avoiding tobacco, engaging in physical activity and raising awareness of CVD risk.

H3Africa AWI-Gen Collaborative Centre: a resource to study the interplay between genomic and environmental risk factors for cardiometabolic diseases in four sub-Saharan African countries

Africa is experiencing a rapid increase in adult obesity and associated cardiometabolic diseases (CMDs). The H3Africa AWI-Gen Collaborative Centre was established to examine genomic and environmental factors that influence body composition, body fat distribution and CMD risk, with the aim to provide insights towards effective treatment and intervention strategies. It provides a research platform of over 10 500 participants, 40–60 years old, from Burkina Faso, Ghana, Kenya and South Africa. Following a process that involved community engagement, training of project staff and participant informed consent, participants were administered detailed questionnaires, anthropometric measurements were taken and biospecimens collected. This generated a wealth of demographic, health history, environmental, behavioural and biomarker data. The H3Africa SNP array will be used for genome-wide association studies. AWI-Gen is building capacity to perform large epidemiological, genomic and epigenomic studies across several African counties and strives to become a valuable resource for research collaborations in Africa.

Youth migration, livelihood prospects and demographic dividend: A comparison of the Census 2011 and Agincourt Health and Demographic Surveillance System in the rural northeast of South Africa

The 2011 South African national census shows a cohort of young adults comprising an increasing share of the population. This finding is borne out in longitudinal data from the Agincourt Health and Demographic Surveillance System (HDSS). This primarily descriptive paper uses the Agincourt HDSS to examine the migration, employment and unemployment patterns in young adults. The study reveals high levels of temporary labour migration linking rural areas to metropolitan areas and secondary urban places. The type of work conducted by young adults in the Agincourt population is predominantly unskilled labour for both sexes. However, there is some evidence of female employment increasing in more educated sectors. Across all working ages there is pronounced unemployment, but the main pressure is felt by the younger adult population. Education and skills development for both sexes should be strengthened to support the country's efforts to vastly improve labour force participation amongst the youth.