Makandwe Nyirenda

Cohort Profile: Africa Centre Demographic Information System (ACDIS) and population-based HIV survey

The health and demography of the South African population has been undergoing substantial changes as a result of the rapidly progressing HIV epidemic. Researchers at the University of KwaZulu-Natal and the South African Medical Research Council established The Africa Centre for Health and Population Studies in 1997 funded by a large core grant from The Wellcome Trust, UK. Given the urgent need for high quality longitudinal data with which to monitor these changes, and with which to evaluate interventions to mitigate impact, a demographic surveillance system (DSS) was established in a rural South African population facing a rapid and severe HIV epidemic. 1 The DSS, referred to as the Africa Centre Demographic Information System (ACDIS), started in 2000. In 2003, population-based HIV testing (also funded by the Wellcome Trust, UK) was started in ACDIS through annual surveys. In this article, we seek to describe the most salient features of ACDIS and the population-based HIV cohort and briefly present some of the most important results to date.

Age at first sex in rural South Africa

Objectives: To identify factors associated with sexual debut and early age at first sex (AFS) among young men and women (12–25 years) in a population with a high prevalence and incidence of HIV in rural South Africa. Methods: Longitudinal data from four rounds (2003–7) of a prospective population-based HIV and sexual behaviour survey in rural KwaZulu-Natal were used to investigate the distribution and predictors of earlier first sex. Survival analyses were used, and each analysis considered men and women separately. Results: Among the 4724 women and 4029 men who were virgins at the beginning of the period, the median AFS was 18.5 and 19.2 years, respectively. In multivariable models, factors associated with earlier AFS across gender were periurban residence (vs rural), ever use of alcohol and knowing at least one person who had HIV, while school attendance had a significant protective effect. Other factors were important for one gender only. Maternal death was significantly associated with earlier AFS for women, in the same way that paternal death was for young men, while mother’s membership of the same household significantly delayed AFS of young men. The analysis of early first sex confirmed the same factors to be important as in the overall analyses for men and women. Conclusion: Given the association of individual, household and community level factors with sexual debut, a multisectorial approach to prevention and targeting in youth programmes is recommended.

An investigation of factors associated with the health and well-being of HIV-infected or HIV-affected older people in rural South Africa

BackgroundDespite the severe impact of HIV in sub-Saharan Africa, the health of older people aged 50+ is often overlooked owing to the dearth of data on the direct and indirect effects of HIV on older people’s health status and well-being. The aim of this study was to examine correlates of health and well-being of HIV-infected older people relative to HIV-affected people in rural South Africa, defined as participants with an HIV-infected or death of an adult child due to HIV-related cause.MethodsData were collected within the Africa Centre surveillance area using instruments adapted from the World Health Organization (WHO) Study on global AGEing and adult health (SAGE). A stratified random sample of 422 people aged 50+ participated. We compared the health correlates of HIV-infected to HIV-affected participants using ordered logistic regressions. Health status was measured using three instruments: disability index, quality of life and composite health score.ResultsMedian age of the sample was 60 years (range 50–94). Women HIV-infected (aOR 0.15, 95% confidence interval (CI) 0.08–0.29) and HIV-affected (aOR 0.20, 95% CI 0.08–0.50), were significantly less likely than men to be in good functional ability. Women’s adjusted odds of being in good overall health state were similarly lower than men’s; while income and household wealth status were stronger correlates of quality of life. HIV-infected participants reported better functional ability, quality of life and overall health state than HIV-affected participants.Discussion and conclusionsThe enhanced healthcare received as part of anti-retroviral treatment as well as the considerable resources devoted to HIV care appear to benefit the overall well-being of HIV-infected older people; whereas similar resources have not been devoted to the general health needs of HIV uninfected older people. Given increasing numbers of older people, policy and programme interventions are urgently needed to holistically meet the health and well-being needs of older people beyond the HIV-related care system.

Translating global health research aims into action: the example of the ALPHA network*

There is increasing consensus on the importance of strengthening global health research to meet health and development goals. Three key global health research aims are to ensure that research (i) addresses priority health needs, (ii) contributes to policy development, and (iii) adds value to investments in developing countries through South–South collaboration and capacity‐strengthening in the South. The ALPHA network (Analysing Longitudinal Population‐based HIV/AIDS data on Africa) is an illustrative example of how these global health research aims can be translated into action. The network facilitates additional collaborative HIV epidemiological research among six independent research projects in Africa studying population‐based cohorts. Under the first of the earlier mentioned aims, the network addresses key epidemiology research issues in HIV/AIDS which are crucial to making progress and monitoring progress in the response against HIV/AIDS. Under the second aim, the network’s scientific programme of research has contributed to strengthening the evidence base on HIV epidemiology in Africa and has informed policy development in areas such as targeted HIV prevention, social support, monitoring epidemic response and epidemic forecasting. Under the third aim, investment in the network has added value to the research investment in the individual projects through capacity development among African researchers as well as through the collaborative research outputs of the individual projects. Lessons from the network are relevant to collaborations facing similar challenges in other areas of global health research. These include the importance of establishing transparent and efficient governance for research collaborations, developing advance consensus on data sharing, ensuring effective communication for networking and demonstrating the added value of research investment in South–South collaborations.

Prevalence and correlates of depression among HIV-infected and -affected older people in rural South Africa.

Background Little is known about depression in older people in sub-Saharan Africa, the associated impact of HIV, and the influence on health perceptions. Objectives Examine the prevalence and correlates of depression; explore the relationship between depression and health perceptions in HIV-infected and -affected older people. Methods In 2010, 422 HIV-infected and -affected participants aged 50+ were recruited into a cross-sectional study. Nurse professionals interviewed participants and a diagnosis of depressive episode was derived from the Composite International Diagnostic Interview (Depression module) using the International Classification of Diseases diagnostic criteria and categorised as major (MDE) or brief (BDE). Results Overall, 42.4% (n=179) had a depressive episode (MDE: 22.7%, n=96; BDE: 19.7%, n=83). Prevalence of MDE was significantly higher in HIV-affected (30.1%, 95% CI 24.0–36.2%) than HIV-infected (14.8%, 95% CI 9.9–19.7%) participants; BDE was higher in HIV-infected (24.6%, 95% CI 18.7–30.6%) than in HIV-affected (15.1%, 95% CI 10.3–19.8%) participants. Being female (aOR 3.04, 95% CI 1.73–5.36), receiving a government grant (aOR 0.34, 95% CI 0.15–0.75), urban residency (aOR 1.86, 95% CI 1.16–2.96) and adult care-giving (aOR 2.37, 95% CI 1.37–4.12) were significantly associated with any depressive episode. Participants with a depressive episode were 2–3 times more likely to report poor health perceptions. Limitations Study limitations include the cross-sectional design, limited sample size and possible selection biases. Conclusions Prevalence of depressive episodes was high. Major depressive episodes were higher in HIV-affected than HIV-infected participants. Psycho-social support similar to that of HIV treatment programmes around HIV-affected older people may be useful in reducing their vulnerability to depression.

Mortality levels and trends by HIV serostatus in rural South Africa

Objective:To examine mortality differentials in HIV-infected and uninfected adults by demographic characteristics and the effect of non-testing on the level and pattern of age-sex specific mortality. Methods:Three annual prospective population-based HIV surveys between 2003 and 2006 provide information regarding individual adult HIV status; households were visited twice a year to collect information about births, deaths, migrations and other demographic, health and socioeconomic data. Deaths and person-years of exposure were aggregated for each calendar year between 2004 and 2006, from which mortality rates were derived. The association between risk factors and mortality was assessed using a Cox proportional hazards model. Results:The observed rate of mortality in individuals who did not consent to HIV testing was four to seven times higher, and that in HIV-infected adults 11–19 times higher than mortality in HIV-negative individuals. After adjusting for age, sex and socioeconomic status, HIV-infected individuals had a ninefold greater hazard of dying than uninfected individuals. Mortality rates increased with age and peak in the 45–54 years age group, irrespective of HIV status. Multivariably, age and sex were significantly associated with the hazard of dying, but place of residency and socioeconomic status were not. Overall mortality declined from 71 to 48 deaths per 1000 person-years between 2005 and 2006. Conclusion:The substantial decline in mortality after 2004 is likely to be largely attributable to the increasing availability of antiretroviral therapy. Detailed investigation of the characteristics of the not-tested individuals is needed to understand their impact on mortality patterns.

Health, wellbeing, and disability among older people infected or affected by HIV in Uganda and South Africa

Objective : To describe and compare the health status, emotional wellbeing, and functional status of older people in Uganda and South Africa who are HIV infected or affected by HIV in their families. Methods : Data came from the general population cohort and Entebbe cohort of the Medical Research Council/Uganda Virus Research Institute, and from the Africa Centre Demographic Information System through cross-sectional surveys in 2009/10 using instruments adapted from the World Health Organization (WHO) Study on Global Ageing and Adult Health (SAGE). Analysis was based on 932 people aged 50 years or older (510 Uganda, 422 South Africa). Results : Participants in South Africa were slightly younger (median age − 60 years in South Africa, 63 in Uganda), and more were currently married, had no formal education, were not working, and were residing in a rural area. Adjusting for socio-demographic factors, older people in South Africa were significantly less likely to have good functional ability [adjusted odds ratio (aOR) 0.72, 95% CI 0.53–0.98] than those in Uganda, but were more likely to be in good subjective wellbeing (aOR 2.15, 95% CI 1.60–2.90). South Africans were more likely to be obese (aOR 5.26, 95% CI 3.46–8.00) or to be diagnosed with hypertension (aOR 2.77, 95% CI 2.06–3.73). Discussion and conclusions : While older peoples health problems are similar in the two countries, marked socio-demographic differences influence the extent to which older people are affected by poorer health. It is therefore imperative when designing policies to improve the health and wellbeing of older people in sub-Saharan Africa that the region is not treated as a homogenous entity.OBJECTIVE To describe and compare the health status, emotional wellbeing, and functional status of older people in Uganda and South Africa who are HIV infected or affected by HIV in their families. METHODS Data came from the general population cohort and Entebbe cohort of the Medical Research Council/Uganda Virus Research Institute, and from the Africa Centre Demographic Information System through cross-sectional surveys in 2009/10 using instruments adapted from the World Health Organization (WHO) Study on Global Ageing and Adult Health (SAGE). Analysis was based on 932 people aged 50 years or older (510 Uganda, 422 South Africa). RESULTS Participants in South Africa were slightly younger (median age - 60 years in South Africa, 63 in Uganda), and more were currently married, had no formal education, were not working, and were residing in a rural area. Adjusting for socio-demographic factors, older people in South Africa were significantly less likely to have good functional ability [adjusted odds ratio (aOR) 0.72, 95% CI 0.53-0.98] than those in Uganda, but were more likely to be in good subjective wellbeing (aOR 2.15, 95% CI 1.60-2.90). South Africans were more likely to be obese (aOR 5.26, 95% CI 3.46-8.00) or to be diagnosed with hypertension (aOR 2.77, 95% CI 2.06-3.73). DISCUSSION AND CONCLUSIONS While older peoples health problems are similar in the two countries, marked socio-demographic differences influence the extent to which older people are affected by poorer health. It is therefore imperative when designing policies to improve the health and wellbeing of older people in sub-Saharan Africa that the region is not treated as a homogenous entity.

Gender differentials in the impact of parental death: Adolescent's sexual behaviour and risk of HIV infection in rural South Africa

Using data from a longitudinal surveillance study from rural South Africa, we investigated the odds of sexual debut, pregnancy and HIV infection of 15- to 19-year-old adolescents by parental survival. Using descriptive statistics and logistic regressions, we examine the relative risk of orphans compared with non-orphans to have ever had sex, being pregnant and being HIV infected, adjusting for age, sex, socio-economic status, education, being employed and residency. Of 8274 adolescents, 42% were orphaned (one or both parents died). Over 80% of adolescents remained in school, but orphans were significantly more likely to lag behind in grade for age. Female adolescent maternal (aOR 1.32, 95% CI 1.07–1.62), paternal (aOR 1.26, 95% CI 1.06–1.49) and dual (aOR 1.37, 95% CI 1.05–1.78) orphans were significantly more likely than non-orphaned females to have ever had sex; among males it was only paternal (aOR 1.27, 95% CI 1.05–1.53) orphans. Maternal (aOR 1.49, 95% CI 1.03–2.15) and dual (aOR 1.74, 95% CI 1.11–2.73) female orphans relative to non-orphaned females were significantly more likely to be HIV infected; male paternal (aOR 3.41, 95% CI 1.37–8.46) and dual (aOR 3.54, 95% CI 1.06–11.86) orphans had over three-fold the odds of being infected. There was strong evidence that death of mother for girls was associated with increased vulnerability to earlier sexual debut and HIV infection, while fathers appeared to play a significant role in both their sons and daughters lives.

Adjusting HIV prevalence for survey non-response using mortality rates: an application of the method using surveillance data from rural South Africa.

Background The main source of HIV prevalence estimates are household and population-based surveys; however, high refusal rates may hinder the interpretation of such estimates. The study objective was to evaluate whether population HIV prevalence estimates can be adjusted for survey non-response using mortality rates. Methodology/Principal Findings Data come from the longitudinal Africa Centre Demographic Information System (ACDIS), in rural South Africa. Mortality rates for persons tested and not tested in the 2005 HIV surveillance were available from routine household surveillance. Assuming HIV status among individuals contacted but who refused to test (non-response) is missing at random and mortality among non-testers can be related to mortality of those tested a mathematical model was developed. Non-parametric bootstrapping was used to estimate the 95% confidence intervals around the estimates. Mortality rates were higher among untested (16.9 per thousand person-years) than tested population (11.6 per thousand person-years), suggesting higher HIV prevalence in the former. Adjusted HIV prevalence for females (15–49 years) was 31.6% (95% CI 26.1–37.1) compared to observed 25.2% (95% CI 24.0–26.4). For males (15–49 years) adjusted HIV prevalence was 19.8% (95% CI 14.8–24.8), compared to observed 13.2% (95% CI 12.1–14.3). For both sexes (15–49 years) combined, adjusted prevalence was 27.5% (95% CI 23.6–31.3), and observed prevalence was 19.7% (95% CI 19.6–21.3). Overall, observed prevalence underestimates the adjusted prevalence by around 7 percentage points (37% relative difference). Conclusions/Significance We developed a simple approach to adjust HIV prevalence estimates for survey non-response. The approach has three features that make it easy to implement and effective in adjusting for selection bias than other approaches. Further research is needed to assess this approach in populations with widely available HIV treatment (ART).

Decreased Chronic Morbidity but Elevated HIV Associated Cytokine Levels in HIV-Infected Older Adults Receiving HIV Treatment: Benefit of Enhanced Access to Care?

Background The association of HIV with chronic morbidity and inflammatory markers (cytokines) in older adults (50+years) is potentially relevant for clinical care, but data from African populations is scarce. Objective To examine levels of chronic morbidity by HIV and ART status in older adults (50+years) and subsequent associations with selected pro-inflammatory cytokines and body mass index. Methods Ordinary, ordered and generalized ordered logistic regression techniques were employed to compare chronic morbidity (heart disease (angina), arthritis, stroke, hypertension, asthma and diabetes) and cytokines (Interleukins-1 and -6, C-Reactive Protein and Tumor Necrosis Factor-alpha) by HIV and ART status on a cross-sectional random sample of 422 older adults nested within a defined rural South African population based demographic surveillance. Results Using a composite measure of all morbidities, controlling for age, gender, BMI, smoking and wealth quintile, HIV-infected individuals on ART had 51% decreased odds (95% CI:0.26-0.92) of current morbidity compared to HIV-uninfected. In adjusted regression, compared to HIV-uninfected, the proportional odds (aPOR) of having elevated inflammation markers of IL6 (>1.56pg/mL) was nearly doubled in HIV-infected individuals on (aPOR 1.84; 95%CI: 1.05-3.21) and not on (aPOR 1.94; 95%CI: 1.11-3.41) ART. Compared to HIV-uninfected, HIV-infected individuals on ART had >twice partial proportional odds (apPOR=2.30;p=0.004) of having non-clinically significant raised hsCRP levels(>1ug/mL); ART-naïve HIV-infected individuals had >double apPOR of having hsCRP levels indicative of increased heart disease risk(>3.9ug/mL;p=0.008). Conclusions Although HIV status was associated with increased inflammatory markers, our results highlight reduced morbidity in those receiving ART and underscore the need of pro-actively extending these services to HIV-uninfected older adults, beyond mere provision at fixed clinics. Providing health services through regular community chronic disease screening would ensure health care reaches all older adults in need.