Impact of antiretroviral therapy on adult HIV prevalence in a low-income rural setting in Uganda: a longitudinal population-based study.

OBJECTIVE: To estimate the contribution to HIV prevalence of lives saved due to the introduction of antiretroviral therapy (ART) in rural Uganda in 2004. DESIGN: Open population-based cohort study. METHODS: An open general population cohort with annual demographic and HIV serostatus data is used to estimate annual HIV prevalence, HIV incidence, and mortality from 2000 to 2010. We calculated standardized mortality rates among HIV-positive adults and the expected number of deaths in the cohort if ART had not been available during 2004-2010, based on the average mortality rate in the 4 years (2000-2003) before ART introduction. RESULTS: During 2004-2010, the estimated prevalence increased by 29% from 6.9% to 8.9%. HIV incidence was 5.6 cases per 1000 person-years in 2004, falling to 3.9 cases per 1000 person-years in 2006, and slightly rising to 5.1 in 2010. There was an increase of 182 in the number of HIV-positive participants during that period, cumulatively 228 lives were saved due to ART. Expected lives saved due to ART accounted for an increasing proportion of the estimated HIV prevalence from 4.0% in 2004 to 29.4% in 2010. CONCLUSIONS: Expected lives saved due to ART largely accounted for the increased estimated HIV prevalence from 2004 to 2010. Because HIV prevalence survey results are important for planning, programming, and policy, their interpretation requires consideration of the increasing impact of ART in decreasing mortality

Planning an Integrated Disease Surveillance and Response System: A Matrix of Skills and Activities

The threat of a global influenza pandemic and the adoption of the World Health Organization (WHO) International Health Regulations (2005) highlight the value of well-coordinated, functional disease surveillance systems. The resulting demand for timely information challenges public health leaders to design, develop and implement efficient, flexible and comprehensive systems that integrate staff, resources, and information systems to conduct infectious disease surveillance and response. To understand what resources an integrated disease surveillance and response system would require, we analyzed surveillance requirements for 19 priority infectious diseases targeted for an integrated disease surveillance and response strategy in the WHO African region

Strengthening public health surveillance and response using the health systems strengthening agenda in developing countries

There is increased interest in strengthening health systems for developing countries. However, at present, there is common uncertainty about how to accomplish this task. Specifically, several nations are faced with an immense challenge of revamping an entire system. To accomplish this, it is essential to first identify the components of the system that require modification. The World Health Organization (WHO) has proposed health system building blocks, which are now widely recognized as essential components of health systems strengthening

HIV Combination Prevention study - Data at months 0, 9 and 15

Dataset and supporting documentation collected as part of the HIV combination prevention study, a cluster randomised trial investigating the feasibility of conducting HIV combination prevention interventions in fishing communities in Uganda. The dataset contains participant-provided responses including condom use, HIV prevention practices, and intervention take-up

Bayesian history matching of complex infectious disease models using emulation: A tutorial and a case study on HIV in Uganda

Advances in scientific computing have allowed the development of complex models that are being routinely applied to problems in disease epidemiology, public health and decision making. The utility of these models depends in part on how well they can reproduce empirical data. However, fitting such models to real world data is greatly hindered both by large numbers of input and output parameters, and by long run times, such that many modelling studies lack a formal calibration methodology. We present a novel method that has the potential to improve the calibration of complex infectious disease models (hereafter called simulators). We present this in the form of a tutorial and a case study where we history match a dynamic, event-driven, individual-based stochastic HIV simulator, using extensive demographic, behavioural and epidemiological data available from Uganda. The tutorial describes history matching and emulation. History matching is an iterative procedure that reduces the simulator's input space by identifying and discarding areas that are unlikely to provide a good match to the empirical data. History matching relies on the computational efficiency of a Bayesian representation of the simulator, known as an emulator. Emulators mimic the simulator's behaviour, but are often several orders of magnitude faster to evaluate. In the case study, we use a 22 input simulator, fitting its 18 outputs simultaneously. After 9 iterations of history matching, a non-implausible region of the simulator input space was identified that was times smaller than the original input space. Simulator evaluations made within this region were found to have a 65% probability of fitting all 18 outputs. History matching and emulation are useful additions to the toolbox of infectious disease modellers. Further research is required to explicitly address the stochastic nature of the simulator as well as to account for correlations between outputs

Efficient History Matching of a High Dimensional Individual-Based HIV Transmission Model

History matching is a model (pre-)calibration method that has been applied to computer models from a wide range of scientific disciplines. In this work we apply history matching to an individual-based epidemiological model of HIV that has 96 input and 50 output parameters, a model of much larger scale than others that have been calibrated before using this or similar methods. Apart from demonstrating that history matching can analyze models of this complexity, a central contribution of this work is that the history match is carried out using linear regression, a statistical tool that is elementary and easier to implement than the Gaussian process--based emulators that have previously been used. Furthermore, we address a practical difficulty with history matching, namely, the sampling of tiny, nonimplausible spaces, by introducing a sampling algorithm adjusted to the specific needs of this method. The effectiveness and simplicity of the history matching method presented here shows that it is a useful tool for the calibration of computationally expensive, high dimensional, individual-based models

Atherogenic Risk Assessment among Persons Living in Rural Uganda

Background. Hypertension and dyslipidemia are independent risk factors for coronary heart disease and commonly coexist. Cardiovascular risk can be reliably predicted using lipid ratios such as the atherogenic index, a useful prognostic parameter for guiding timely interventions. Objective. We assessed the cardiovascular risk profile based on the atherogenic index of residents within a rural Ugandan cohort. Methods. In 2011, a population based survey was conducted among 7507 participants. Sociodemographic characteristics, physical measurements (blood pressure, weight, height, and waist and hip circumference), and blood sampling for non fasting lipid profile were collected for each participant. Atherogenic risk profile, defined as logarithm base ten of (triglyceride divided by high density lipoprotein cholesterol), was categorised as low risk (0.24). Results. Fifty-five percent of participants were female and the mean age was 49.9 years (SD± 20.2). Forty-two percent of participants had high and intermediate atherogenic risk. Persons with hypertension, untreated HIV infection, abnormal glycaemia, and obesity and living in less urbanised villages were more at risk. Conclusion. A significant proportion of persons in this rural population are at risk of atherosclerosis. Key identified populations at risk should be considered for future intervention against cardiovascular related morbidity and mortality. The study however used parameters from unfasted samples that may have a bearing on observed results

The impact of the parenting for respectability programme on violent parenting and intimate partner relationships in Uganda: a pre-post study

Background There is a growing need for interventions that reduce both violence against children and intimate partner violence in low- and middle-income countries. However, few parenting interventions deliberately address this link. We tested the feasibility of a 16-session group-based parenting programme, Parenting for Respectability, in semi-rural Ugandan communities. Methods This was a pre-post study with parents and their children (N = 484 parents; 212 children). Results Pre-post comparisons found large effects for parent-reported reduced harsh parenting (Cohen’s f2 = 0.41 overall; f2 = 0.47 (among session attendees); with an overall reduction of 26% for harsh parenting. Session attendees reported higher reductions than non-attendees (p = 0.014), and male caregivers reported higher reductions than female caregivers (p<0.001). Children also reported reduced harsh parenting by attending fathers (f2 = 0.64 overall; f2 = 0.60) and attending mothers (f2 = 0.56 overall; f2 = 0.51); with reduction in harsh parenting ranging between 27% to 29% in the various categories. Overall, spousal violence reduced by 27% (f2 = 0.19 overall; f2 = 0.26 (among session attendees). Both parents and children reported reduced dysfunctional parent relationships; parents: f2 = 0.19 overall; f2 = 0.26 (among session attendees); and children: f2 = 0.35 overall; f2 = 0.32 (for attending parents); with reductions ranging between 22% to 28%. Parents who attended more than 50% of the program reported greater effects on reduced dysfunctional relationships than those who attended less than half of the program (B = -0.74, p = 0.013). All secondary outcomes were improved with f2 ranging between 0.08 and 0.39; and improvements ranging between 6% and 28%. Conclusion Results suggest the importance of more rigorous testing to determine program effectiveness

Effect of HIV-1 subtypes on disease progression in rural Uganda: a prospective clinical cohort study.

OBJECTIVE: We examined the association of HIV-1 subtypes with disease progression based on three viral gene regions. DESIGN: A prospective HIV-1 clinical cohort study in rural Uganda. METHODS: Partial gag, env and pol genes were sequenced. Cox proportional hazard regression modelling was used to estimate adjusted hazard ratios (aHRs) of progression to: CD4≤250, AIDS onset and death, adjusted for sex, age and CD4 count at enrolment. RESULTS: Between 1990 and 2010, 292 incident cases were subtyped: 25% had subtype A, 45% had D, 26% had A/D recombinants, 1% had C and 4% were other recombinant forms. Of the 278 incident cases included in the disease progression analysis, 62% progressed to CD4≤250, 32% to AIDS, and 34% died with a higher proportion being among subtype D cases. The proportions of individuals progressing to the three endpoints were significantly higher among individuals infected with subtype D. Throughout the study period, individuals infected with subtype D progressed faster to CD4≤250, adjusted HR (aHR), (95% CI) = 1.72 (1.16-2.54), but this was mainly due to events in the period before antiretroviral therapy (ART) introduction, when individuals infected with subtype D significantly progressed faster to CD4≤250 than subtype A cases; aHR (95% CI) = 1.78 (1.01-3.14). CONCLUSIONS: In this population, HIV-1 subtype D was the most prevalent and was associated with faster HIV-1 disease progression than subtype A. Further studies are needed to examine the effect of HIV-1 subtypes on disease progression in the ART period and their effect on the virological and immunological ART outcomes