In a recent study published in the PLOS Global Public Health Journal, researchers assessed five-year trends in human immunodeficiency virus (HIV) viral load (VL) suppression (VLS) rates in Ekurhuleni City of South Africa between January 2012 and December 2016.
Study: Small area analysis of HIV viral load suppression patterns in a high priority district (2012–2016), South Africa. Image Credit: CoronaBorealisStudio/Shutterstock.com
Background
Globally, elevated VLS rates indicate the success of therapeutic programs for HIV. In 2013, antiretroviral therapy (ART) agents were extensively rolled out.
VL assessments were scaled up to attain prior (90-90-90) and current (95-95-95) targets of the Joint United Nations (UN) Programme on HIV/acquired immunodeficiency syndrome (UNAIDS), by the year 2030, for ultimate control of HIV.
Widespread antiretroviral therapy coverage and high VLS rates would decrease the onward transmission and prevalence of HIV. Lower-scale evaluations of HIV programs are required to reveal variations that may not be apparent nationally.
About the study
In the present ecological study, researchers utilized five years of human immunodeficiency virus program data for Ekurhuleni. They did so to evaluate VLS rates, determine ward-level spatiotemporal associations, and the universal test and treat (UTT) roll-out's influence in 2016. They also forecasted VLS rates between January 2017 and December 2021.
The study utilized routinely obtained surveillance and clinical information on the national human immunodeficiency virus infection treatment program provided by 88 Ekurhuleni Metropolitan Municipality (EMM) wards.
From January 2012 to December 2016, 26,222 tests were conducted to determine HIV viral load among 2,817 individuals. As a secondary assessment, the estimators of high VLS were identified, considering time and space.
For the analysis, aggregated data for HIV indicators were obtained from primary healthcare (PHC) EMM centers from 2012 to 2016.
HIV VL data were provided by the national health laboratory services (NHLS) of South Africa. District health information system (DHIS) data were used to assess clinical-level uptake of ART in Ekurhuleni.
In addition, data were obtained on the participants' age, sex, tuberculosis (TB) diagnosis, starting data of ART therapy, and VL counts. Blood samples were obtained from the participants to determine HIV VL.
Deidentified data of HIV patients accessing care centers, and having documented clinic visits during the study, were used to assess VL suppression (VLS, less than 1000 copies per mL).
Ward-level population characteristics, including the female count, the number of individuals in each ward, individuals with no household income, and the percentage of low-level literacy, were estimated using the 2011 Census data.
Spatio-temporal regression analyses were performed, including g ordinary least squares-type regression (OLS) and geographically weighted-type regression (GWR).
Sensitivity analyses were performed by considering the VLS cutoff value of <400.0 copies per mL and limiting the period of analysis to up to the August 2016 period before the nationwide UTT roll-out.
Results
Between January 2012 and December 2016, the team obtained 41,644 blood samples from the study participants, 62% (n=25,631) of whom were men, and the median participant age was 39.0 years.
The participants accessed 99 primary healthcare centers, across 88 EMM wards, for regular HIV-related care. In total, 26,222 human immunodeficiency virus VL samples, provided by 2,817 individuals, were analyzed.
The prevalence of HIV in the EMM wards rose from 32.0% in 2012 to 37.0% in 2016. During the period, the percentage of people living with HIV (PLHIV) initiating antiretroviral therapy coverage increased steadily from 32.0% to 81.0%.
In Ekurhuleni, 66% and 57% of VL test report for cutoffs of below 1,000 copies per mL and below 400 copies per mL, respectively, showed VLS.
The VLS proportions increased annually, from 48% (2012), 58% (2013), 63% (2014), to 67% (2015), followed by a reduction in 2016 (61%).
For every percent rise in antiretroviral therapy initiation, a 35.0% increase in high VLS rates was observed (RR 1.4), and every percent increase in the ward occupancy by females resulted in a 44.0% increase in the high VLS rates (RR 1.4). High and low ward-level VLS clusters were found.
High VLS clusters included the southern district regions of Kempton Park, Benoni, Boksburg, and Alberton. Low VLS clusters included regions of the eastern district, such as Langaville, Thokoza, and Brakpan.
VLS rates in the city were below the 90.0% target set by UNAIDS. Heterogeneous VLS rates were observed across wards during the study period. Sensitivity analysis yielded similar results.
VLS proportions in EMM reduced post-UTT roll-out immediately. VLS (less than 1,000.0 copies per mL) ranged between 65% in January 2016, 70% through the end-August period of 2016, and 58% by the end-December period of 2016.
VLS (less than 400 copies per mL) proportions were lower before and post-roll-out of UTT. The predicted VLS rates showed good matching with the observed rates.
The forecasted VLS rates considering the 1000 copies per mL cutoff, rose in 2017 before reducing in 2018. Converse findings were observed for the forecasted VLS rates considering the 400.0 copies per mL cutoff, increasing between 2017 and 2019, followed by reductions after mid-2019.
The associations between female counts and high VLS and ART initiation and high VLS were significant across the years.
Conclusions
Overall, the study findings showed the presence of spatiotemporal heterogeneity in VLS in Ekurhuleni, indicating that targeted health interventions are required to improve and retain antiretroviral therapy recipients receiving care and optimize VLS.
The findings provide insights into HIV programs by identifying wards that require linking and retaining support in providing care services.
High and low levels of VLS rates were clustered geographically across time and space. Understanding VLS variations could guide interventions for improving HIV programs and monitoring retention at care centers, lowering HIV transmission and the incidence of HIC infections.
High VLS rates correlated positively with increasing antiretroviral therapy coverage and the proportion of females, although the finding did not apply to all five years. Applying the cutoff of <400.0 copies per mL reduced VLS by 15.0%, highlighting gaps in monitoring, managing, and accessibility of effective ART.
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