Modelling the epidemiologic impact of achieving UNAIDS fast-track 90-90-90 and 95-95-95 targets in South Africa

Agent based modelling of blood borne viruses: a scoping review

BACKGROUND

The models that historically have been used to model infectious disease outbreaks are equation-based and statistical models. However, these models do not capture the impact of individual and social factors that affect the spread of common blood-borne viruses (BBVs) such as human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B virus (HBV). Agent-based modelling (ABM) is an alternative modelling approach that is gaining popularity in public health and epidemiology. As the field expands, it is important to understand how ABMs have been applied. In this context, we completed a scoping review of research that has been done on the ABM of BBVs.

METHOD

The inclusion/exclusion criteria were drafted using the idea of Population, Concept, and Context (PCC). The Preferred Reporting Item for Systematic Reviews and Meta-Analysis, an extension to scoping review (PRISMA-ScR), was employed in retrieving ABM literature that studied BBVs. Three databases (Scopus, Pubmed, and Embase) were systematically searched for article retrieval. 200 articles were retrieved from all the databases, with 10 duplicates. After removing the duplicates, 190 papers were screened for inclusion. After analysing the remaining articles, 70 were excluded during the abstract screening phase, and 32 were excluded during the full-text decision. Eighty-eight were retained for the scoping review analysis. To analyse this corpus of 88 papers, we developed a five-level taxonomy that categorised each paper based first on disease type, then transmission mechanism, then modelled population, then geographic location and finally, model outcome.

RESULTS

The result of this analysis show significant gaps in the ABM of BBV literature, particularly in the modeling of social and individual factors influencing BBV transmission.

CONCLUSION

There is a need for more comprehensive models that address various outcomes across different populations, transmission and intervention mechanisms. Although ABMs are a valuable tool for studying BBVs, further research is needed to address existing gaps and improve our understanding of individual and social factors that influence the spread and control of BBVs. This research can inform researchers, modellers, epidemiologists, and public health practitioners of the ABM research areas that need to be explored to reduce the burden of BBVs globally.

The impact of same-day antiretroviral therapy initiation on retention in care and clinical outcomes at four eThekwini clinics, KwaZulu-Natal, South Africa

BACKGROUND

Same-day initiation (SDI) of antiretroviral therapy (ART) increases ART uptake, however retention in care after ART initiation remains a challenge. Public health behaviours, such as retention in HIV care and adherence to antiretroviral therapy (ART) pose major challenges to reducing new Human Immunodeficiency Virus (HIV) transmission and improving health outcomes among HIV patients.

METHODS

We evaluated 6-month retention in care, and clinical outcomes of an ART cohort comprising of SDI and delayed ART initiators. We conducted a 6 months' observational prospective cohort study of 403 patients who had been initiated on ART. A structured questionnaire was used to abstract data from patient record review which comprised the medical charts, laboratory databases, and Three Interlinked Electronic Registers.Net (TIER.Net). Treatment adherence was ascertained by patient visit constancy for the clinic scheduled visit dates. Retention in care was determined by status at 6 months after ART initiation.

RESULTS

Among the 403 participants enrolled in the study and followed up, 286 (70.97%) and 267 (66.25%) complied with scheduled clinics visits at 3 months and 6 months, respectively. One hundred and thirteen (28.04%) had been loss to follow-up. 17/403 (4.22%) had died and had been out of care after 6 months. 6 (1.49%) had been transferred to other health facilities and 113 (28.04%) had been loss to follow-up. Among those that had been lost to follow-up, 30 (33.63%) deferred SDI while 75 (66.37%) initiated ART under SDI. One hundred and eighty-nine (70.79%) participants who had remained in care were SDI patients while 78 (29.21%) were SDI deferred patients. In the bivariate analysis; gender (OR: 1.672; 95% CI: 1.002-2.791), number of sexual partners (OR: 2.092; 95% CI: 1.07-4.061), age (OR: 0.941; 95% CI: 0.734-2.791), ART start date (OR: 0.078; 95% CI: 0.042-0.141), partner HIV status (OR: 0.621; 95% CI: 0.387-0.995) and the number of hospitalizations after HIV diagnosis (OR: 0.173; 95% CI: 0.092-0.326). were significantly associated with viral load detection. Furthermore, SDI patients who defaulted treatment were 2.4 (95% CI: 1.165-4.928) times more likely to have increased viral load than those who had been returned in care.

CONCLUSION

Viral suppression under SDI proved higher but with poor retention in care. However, the results also emphasise a vital need, to not only streamline processes to increase immediate ART uptake further, but also to ensure retention in care.

HIV self-testing: a cross-sectional survey conducted among students at a tertiary institution in Johannesburg, South Africa in 2020

Background

Despite the growing evidence for reasonable acceptance and the willingness to use HIV self-testing (HIVST), South Africa has not yet fully explored HIVST.

Objective

This study's objective was to determine knowledge, attitudes, and practices for HIVST among students aged 18 to 29 years from the University of the Witwatersrand, Johannesburg.

Methods

An online cross-sectional self-administered survey was used to collect data from 01 January 2020 to 31 June 2020. Chi-squared test was used to determine the contribution between categorical variables and HIVST outcomes at a P-value of ≤0.05. Logistic regression was performed to analyze the association between categorical variables with HIVST at a 95% confidence interval.

Results

A total of 227 students were included and more than half were females and 68% were between 20 and 24 years of age. Only 15% reported prior access to HIVST. Almost all students (99%) indicated that they would confirm self-test results if positive. Age group 25-29 (aOR 3.43; 95% CI 1.7-77) was associated with HIVST access compared to ≤19 and 24-29 age groups.

Conclusions

HIVST awareness was generally high among this study population. Of concern is the extremely low number of students who had previously used HIVST, as well as those who were unaware of HIVST's existence. Our findings highlight a necessity for HIVST advocacy in South Africa that provides information on where and how HIVST kits can be accessed to potentially upscale HIV testing - essential for achieving UNAIDS targets towards the elimination of HIV/AIDS epidemic as a public health threat.

Factors Influencing Rapid Antiretroviral Therapy Initiation at Four eThekwini Clinics, KwaZulu-Natal, South Africa

Timely uptake of Antiretroviral therapy considerably improves the health of people living with the Human Immunodeficiency virus. We conducted a cross-sectional study of newly HIV diagnosed individuals in four clinics in eThekwini municipality, KwaZulu-Natal. Data was collected between June 2020 and December 2020. Participants completed an interviewer-administered questionnaire after HIV testing, on the day of HIV diagnosis. We evaluated factors influencing uptake of same-day ART initiation in eThekwini clinics, KwaZulu Natal, South Africa. Demographic information, health status, sexual behaviour, knowledge of universal test and treat (UTT), ART initiation uptake, and disclosure data was collected. Among the 403 participants, same-day initiation (SDI) was 69.2% (n = 279). We observed the number of sexual partners (aOR 0.35; 95% CI 0.15–0.81), HIV status of the partner (aOR 5.03; 95% CI 2.74–9.26) and knowledge of UTT (aOR 1.97; 95% CI 1.34–2.90) were identified as major factors influencing uptake of same-day ART initiation. More strategies are needed to achieve the SDI uptake within the framework of UTT.

Effect of perceived HIV risk on initiation of antiretroviral therapy during the universal test and treat era in South Africa

BACKGROUND

South Africa has not achieved the 90-90-90 goals, in part due to low rates of antiretroviral therapy (ART) initiation among those aware of their HIV status. Perceived risk of HIV at the time of testing may affect likelihood of rapid ART initiation. The purpose of this study was to evaluate factors associated with perceived risk of HIV and the relationship between perceived HIV risk and rapid ART initiation during the universal test and treat era which was adapted in October 2016.

METHODS

We conducted a prospective study of adults undergoing HIV testing from October 2016-February 2019 at Ithembalabantu Clinic in Durban. Eligible participants reported not previously being diagnosed with HIV. Before HIV testing, participants were asked to assess their perceived HIV risk on a four-level scale. We categorized "definitely not" and "probably not going to acquire HIV" as a low perceived risk, and "probably will" and "definitely will become HIV-infected" as a high perceived risk of HIV infection. Participants were followed for up to 14 months following HIV testing to assess ART initiation.

RESULTS

Among 1519 people newly diagnosed with HIV, 55% were female and mean age was 33 years. Among those, 1382 (90.9%) had a high HIV risk perception and 137 (9.1%) reported low HIV risk perception. In the low risk group individuals were more likely to be female (58% vs 55%), unemployed (62% vs 59%), have a partner with unknown HIV status (61% vs 55%) compared to the high risk group. 83.2% of those with low HIV risk perception reported previously HIV testing compared 91.5% of those with high HIV risk perception. In the multivariate model, males were associated with a higher chances of initiating ART compared to females (adjusted hazard ratio (aHR): 1.187, CI 1.187 (1.060-1.329) and being unemployed (aHR 0.767 CI (0.650-0.905). Those with a low HIV risk perception were less likely to initiate ART 125 (91%) vs 1310 (95%) p = 0.022), and took longer to initiate on ART after HIV diagnosis (11 days' vs 4 days, p = 0.042).

CONCLUSION

Factors associated with high HIV risk perception included being unemployed, single, and having a partner of unknown HIV status. People living with HIV (PLHIV) in South Africa who had a low self-perceived risk to HIV infection were less likely to initiate ART. Assessing self-perceived risk of HIV infection may help direct counselling and improve ART initiation to achieve universal 90-90-90 goal.

Mixed-method estimation of population-level HIV viral suppression rate in the Western Cape, South Africa

INTRODUCTION

There are few population-wide data on viral suppression (VS) that can be used to monitor programmatic targets in sub-Saharan Africa. We describe how routinely collected viral load (VL) data from antiretroviral therapy (ART) programmes can be extrapolated to estimate population VS and validate this using a combination of empiric and model-based estimates.

METHODS

VL test results from were matched using a record linkage algorithm to obtain linked results for individuals. Test-level and individual-level VS rates were based on test VL values <1000 cps/mL, and individual VL <1000 cps/mL in a calendar year, respectively. We calculated population VS among people living with HIV (PLWH) in the province by combining census-derived midyear population estimates, HIV prevalence estimates and individual level VS estimates from routine VL data.

RESULTS

Approximately 1.9 million VL test results between 2008 and 2018 were analysed. Among individuals in care, VS increased from 85.5% in 2008 to 90% in 2018. Population VS among all PLWH in the province increased from 12.2% in 2008 to 51.0% in 2017. The estimates derived from this method are comparable to those from other published studies. Sensitivity analyses showed that the results are robust to variations in linkage method, but sensitive to the extreme combinations of assumed VL testing coverage and population HIV prevalence.

CONCLUSION

While validation of this method in other settings is required, this approach provides a simple, robust method for estimating population VS using routine data from ART services that can be employed by national programmes in high-burden settings.

Health Care Providers' Challenges to High-Quality HIV Care and Antiretroviral Treatment Retention in Rural South Africa

Provision of high-quality HIV care is challenging, especially in rural primary care clinics in high HIV burden settings. We aimed to better understand the main challenges to quality HIV care provision and retention in antiretroviral treatment (ART) programs in rural South Africa from the health care providers' perspective. We conducted semi-structured qualitative interviews with 23 providers from nine rural clinics. Using thematic and framework analysis, we found that providers and patients face a set of complex and intertwined barriers at the structural, programmatic, and individual levels. More specifically, analyses revealed that their challenges are primarily structural (i.e., health system- and microeconomic context-specific) and programmatic (i.e., clinic- and provider-specific) in nature. We highlight the linkages that providers draw between the challenges they face, the motivation to do their job, the quality of the care they provide, and patients' dissatisfaction with the care they receive, all potentially resulting in poor retention in care.

Simulating the End of AIDS in New York: Using Participatory Dynamic Modeling to Improve Implementation of the Ending the Epidemic Initiative

OBJECTIVES

In 2014, the governor of New York announced the Ending the Epidemic (ETE) plan to reduce annual new HIV infections from 3000 to 750, achieve a first-ever decrease in HIV prevalence, and reduce AIDS progression by the end of 2020. The state health department undertook participatory simulation modeling to develop a baseline for comparing epidemic trends and feedback on ETE strategies.

METHODS

A dynamic compartmental model projected the individual and combined effects of 3 ETE initiatives: enhanced linkage to and retention in HIV treatment, increased preexposure prophylaxis (PrEP) among men who have sex with men, and expanded housing assistance. Data inputs for model calibration and low-, medium-, and high-implementation scenarios (stakeholders' rollout predictions, and lower and upper bounds) came from surveillance and program data through 2014, the literature, and expert judgment.

RESULTS

Without ETE (baseline scenario), new HIV infections would decline but remain >750, and HIV prevalence would continue to increase by 2020. Concurrently implementing the 3 programs would lower annual new HIV infections by 16.0%, 28.1%, and 45.7% compared with baseline in the low-, medium-, and high-implementation scenarios, respectively. In all concurrent implementation scenarios, although annual new HIV infections would remain >750, there would be fewer new HIV infections than deaths, yielding the first-ever decrease in HIV prevalence. PrEP and enhanced linkage and retention would confer the largest population-level changes.

CONCLUSIONS

New York State will achieve 1 ETE benchmark under the most realistic (medium) implementation scenario. Findings facilitated framing of ETE goals and underscored the need to prioritize men who have sex with men and maintain ETE's multipronged approach, including other programs not modeled here.

"There is no fear in me … well, that little fear is there": dualistic views towards HIV testing among South African adolescent girls and young women

In spite of the high HIV burden and high prevalence and incidence of HIV infection among adolescent girls and young women (AGYW) in South Africa, uptake of HIV testing in this population falls short of the UNIADS 90-90-90 targets, leading to late diagnosis, late entry into HIV care and treatment, and poor uptake of prevention services. There is a critical need to update and deepen our understanding of attitudes towards testing in this population, in order to appropriately respond to their specific needs. This article reports on findings from an exploration of perceptions of HIV testing and testing behaviour amongst AGYW in South Africa using a combination of quantitative and qualitative data. Analysis included data on testing behaviour and reasons for never testing from a survey conducted with 4 399 AGYW aged 15-24 years in six provinces. Combined with survey data is qualitative analysis from 63 in-depth interviews and 24 focus group discussions with 237 AGYW from five provinces. Findings revealed complex, dualistic and often contradictory views towards HIV testing in this population, with fear of HIV and the consequences of testing positive existing alongside a lack of concern towards HIV infection because of the availability and accessibility of antiretrovirals. These findings can help to address barriers to HIV testing in this population and ensure appropriateness of future interventions and HIV messaging.

Effects of a peer educator program for HIV status disclosure and health system strengthening: Findings from a clinic-based disclosure support program in Mozambique

BACKGROUND

In Mozambique, HIV counseling and testing (HCT) rates are low and the cascade (or continuum) of care is poor. Perhaps more importantly, low disclosure rates and low uptake of joint testing are also related to both (1) limitations on access to services and (2) the availability of trained staff. We describe the implementation and impact of a disclosure support implemented by peer educators (PE).

METHODS

Ten PEs, previously trained in basic HIV and post-test counseling, completed additional training on providing disclosure support for newly-diagnosed persons living with HIV (PLH).

RESULTS

Of the 6,092 persons who received HCT, 677 (11.1%) tested positive. Any newly-diagnosed PLH who was tested when PEs were present (606 / 677) was approached about participating in the disclosure program; of these, 94.2% of PLH (n = 574) agreed to participate. Of these, at follow-up (between 1 day and 3 months later, depending on client inclination and availability) 91.9% (n = 528) said that they had disclosed their HIV infection, of whom 66.9% (n = 384) were female and 24.1% (n = 144) male. In turn, 92.7% of partners (n = 508) who had received HIV-related exposure information were tested; of these, 78.7% (n = 400) were found to be HIV-positive. Of the latter, 96.3% (n = 385) were then seen by health care providers and referred for further diagnosis and treatment.

CONCLUSIONS

Supporting newly-diagnosed PLH is important both for their own health and that of others. For the newly-diagnosed, there are extensive challenges related to understanding the implications of their illness; social support from clinical care teams can be vital in planning and coping. Our study has shown that such support of PLH is also crucial to disclosure, in part via improving awareness of positive health implications for (and from) family, friends and other support networks.