90‐90‐90 by 2020? Estimation and projection of the adult HIV epidemic and ART programme in Zimbabwe – 2017 to 2020

Abstract

IntroductionThe 90‐90‐90 targets set by the United Nations aspire to 73% of people living with HIV (PLHIV) being virally suppressed by 2020. Using the HIV Synthesis Model, we aim to mimic the epidemic in Zimbabwe and make projections to assess whether Zimbabwe is on track to meet the 90‐90‐90 targets and assess whether recently proposed UNAIDS HIV transition metrics are likely to be met.MethodsWe used an approximate Bayesian computation approach to identify model parameter values which result in model outputs consistent with observed data, evaluated using a calibration score. These parameter values were then used to make projections to 2020 to compare with the 90‐90‐90 targets and other key indicators. We also calculated HIV transition metrics proposed by UNAIDS (percentage reduction in new HIV infections and AIDS‐related mortality from 2010 to 2020, absolute rate of new infections and AIDS‐related mortality, incidence–mortality ratio and incidence–prevalence ratios).ResultsAfter calibration, there was general agreement between modelled and observed data. The median predicted outcomes in 2020 were: proportion of PLHIV (aged 15 to 65) diagnosed 0.91 (90% uncertainty range 0.87, 0.94) (0.84 men, 0.95 women); of those diagnosed, proportion on treatment 0.92 (0.90, 0.93); of those receiving treatment, proportion with viral suppression 0.86 (0.81, 0.91). This results in 72% of PLHIV having viral suppression in 2020. We estimated a percentage reduction of 36.5% (13.7% increase to 67.4% reduction) in new infections from 2010 to 2020, and of 30.4% (9.7% increase to 56.6% reduction) in AIDS‐related mortality (UNAIDS target 75%). The modelled absolute rates of HIV incidence and AIDS‐related mortality in 2020 were 5.48 (2.26, 9.24) and 1.93 (1.31, 2.71) per 1000 person‐years respectively. The modelled incidence–mortality ratio and incidence–prevalence ratios in 2020 were 1.05 (0.46, 1.66) and 0.009 (0.004, 0.013) respectively.ConclusionsOur model was able to produce outputs that are simultaneously consistent with an array of observed data and predicted that while the 90‐90‐90 targets are within reach in Zimbabwe, increased efforts are required in diagnosing men in particular. Calculation of the HIV transition metrics suggest increased efforts are needed to bring the HIV epidemic under control.

Pangea-Hiv 2

“…Indeed, prevalence of transmitted resistance is increasing throughout the generalized epidemics in Africa [52]. This supports modelling work suggesting that 15% of new infections could be associated with drug resistance mutations by 2020 [53]. The source of resistance transmission can either be from those with virological failure on treatment, or from those themselves untreated but having recently been infected with drug-resistant virus.…”

Strengthening the scale‐up and uptake of effective interventions for sex workers for population impact in Zimbabwe

“…A woman is designated a condomless sex FSW if she has at least three condomless sex partners in a three‐month period in the past year. We further consider that a proportion of women are FSW but that they always use condoms (and thus have no possibility of acquisition or transmission of HIV) .…”

“…For this paper, the model was calibrated to data from Zimbabwe. Data items to which the model is calibrated are HIV prevalence, HIV incidence, number of HIV tests performed per year, PLHIV with known status, number receiving ART, number on second line, proportion with viral suppression, proportion with resistance, number of pregnant women and number of FSW . The data from RDS surveys are used to inform the calibration in respect of the number of FSW as well as prevalence among FSW and we have further compared the model outputs with observed sex worker programme data on the cascade of HIV care .…”

Estimating the Population Size of Female Sex Workers in Zimbabwe: Comparison of Estimates Obtained Using Different Methods in Twenty Sites and Development of a National-Level Estimate

“…38 A mathematical model of HIV in Zimbabwe has estimated that there were 127,385 (lower and upper bounds 60,225–200,020) adult women in Zimbabwe who had had at least 3 condomless sex partners in any given 3-month period in the previous year. 39 It is plausible that the women who were counted as FSW in our study are a subset of the group estimated in the model. Exactly how these different populations relate to and overlap with each other, what their varying service needs are, and how services should be provided, requires further understanding.…”