Modelling cervical cancer elimination using single-visit screening and treatment strategies in the context of high HIV prevalence: estimates for KwaZulu-Natal, South Africa

Preventing tuberculosis with community-based care in an HIV-endemic setting: a modelling analysis

INTRODUCTION

Antiretroviral therapy (ART) and tuberculosis preventive treatment (TPT) both prevent tuberculosis (TB) disease and deaths among people living with HIV. Differentiated care models, including community-based care, can increase the uptake of ART and TPT to prevent TB in settings with a high burden of HIV-associated TB, particularly among men.

METHODS

We developed a gender-stratified dynamic model of TB and HIV transmission and disease progression among 100,000 adults ages 15-59 in KwaZulu-Natal, South Africa. We drew model parameters from a community-based ART initiation and resupply trial in sub-Saharan Africa (Delivery Optimization for Antiretroviral Therapy, DO ART) and other scientific literature. We simulated the impacts of community-based ART and TPT care programmes during 2018-2027, assuming that community-based ART and TPT care were scaled up to similar levels as in the DO ART trial (i.e. ART coverage increasing from 49% to 82% among men and from 69% to 83% among women) and sustained for 10 years. We projected the number of TB cases, deaths and disability-adjusted life years (DALYs) averted relative to standard, clinic-based care. We calculated programme costs and incremental cost-effectiveness ratios from the provider perspective.

RESULTS

If community-based ART care could be implemented with similar effectiveness to the DO ART trial, increased ART coverage could reduce TB incidence by 27.0% (range 21.3%-34.1%) and TB mortality by 34.6% (range 24.8%-42.2%) after 10 years. Increasing both ART and TPT uptake through community-based ART with TPT care could reduce TB incidence by 29.7% (range 23.9%-36.0%) and TB mortality by 36.0% (range 26.9%-43.8%). Community-based ART with TPT care reduced gender disparities in TB mortality rates, with a projected 54 more deaths annually among men than women (range 11-103) after 10 years of community-based care versus 109 (range 41-182) in standard care. Over 10 years, the mean cost per DALY averted by community-based ART with TPT care was $846 USD (range $709-$1012).

CONCLUSIONS

By substantially increasing coverage of ART and TPT, community-based care for people living with HIV could reduce TB incidence and mortality in settings with high burdens of HIV-associated TB and reduce TB gender disparities.

Enhanced cervical cancer and HIV interventions reduce the disproportionate burden of cervical cancer cases among women living with HIV: A modeling analysis

INTRODUCTION

Women living with HIV experience heightened risk of cervical cancer, and over 50% of cases in Southern Africa are attributed to HIV co-infection. Cervical cancer interventions tailored by HIV status delivered with HIV antiretroviral therapy (ART) for treatment can decrease cancer incidence, but impact on HIV-related disparities remains understudied.

METHODS

Using a dynamic model calibrated to KwaZulu-Natal, South Africa, we projected HIV prevalence, cervical cancer incidence, and proportion of cancer cases among women living with HIV between 2021-2071. Relative to the status quo of moderate intervention coverage, we modeled three additive scenarios: 1) ART scale-up only; 2) expanded human papillomavirus (HPV) vaccination, screening, and treatment; and 3) catch-up HPV vaccination and enhanced screening for women living with HIV.

RESULTS

Under the status quo, HIV prevalence among women aged 15+ decreased from a median of 35% [Uncertainty Range (UR): 26-42%] in 2021 to 25% [19-34%] in 2071. The proportion of cervical cancer cases that were women living with HIV declined from 73% [63-86%] to 58% [47-74%], but incidence remained 4.3-fold [3.3-5.7] that of women without HIV. ART scale-up reduced HIV prevalence in 2071, but increased the incidence rate ratio to 5.2 [3.7-7.3]. Disparities remained after expanding cancer interventions for all women (incidence rate ratio: 4.8 [3.6-7.6]), while additional catch-up HPV vaccination and screening for women living with HIV decreased the incidence rate ratio to 2.7 [1.9-3.4] in 2071.

CONCLUSIONS

Tailored cervical cancer interventions for women living with HIV can counteract rising cancer incidence incurred by extended life expectancy on ART and reduce disparate cancer burden.

Cost-effectiveness of single-visit cervical cancer screening in KwaZulu-Natal, South Africa: a model-based analysis accounting for the HIV epidemic

Introduction

Women living with human immunodeficiency virus (WLHIV) face elevated risks of human papillomavirus (HPV) acquisition and cervical cancer (CC). Coverage of CC screening and treatment remains low in low-and-middle-income settings, reflecting resource challenges and loss to follow-up with current strategies. We estimated the health and economic impact of alternative scalable CC screening strategies in KwaZulu-Natal, South Africa, a region with high burden of CC and HIV.

Methods

We parameterized a dynamic compartmental model of HPV and HIV transmission and CC natural history to KwaZulu-Natal. Over 100 years, we simulated the status quo of a multi-visit screening and treatment strategy with cytology and colposcopy triage (South African standard of care) and six single-visit comparator scenarios with varying: 1) screening strategy (HPV DNA testing alone, with genotyping, or with automated visual evaluation triage, a new high-performance technology), 2) screening frequency (once-per-lifetime for all women, or repeated every 5 years for WLHIV and twice for women without HIV), and 3) loss to follow-up for treatment. Using the Ministry of Health perspective, we estimated costs associated with HPV vaccination, screening, and pre-cancer, CC, and HIV treatment. We quantified CC cases, deaths, and disability-adjusted life-years (DALYs) averted for each scenario. We discounted costs (2022 US dollars) and outcomes at 3% annually and calculated incremental cost-effectiveness ratios (ICERs).

Results

We projected 69,294 new CC cases and 43,950 CC-related deaths in the status quo scenario. HPV DNA testing achieved the greatest improvement in health outcomes, averting 9.4% of cases and 9.0% of deaths with one-time screening and 37.1% and 35.1%, respectively, with repeat screening. Compared to the cost of the status quo ($12.79 billion), repeat screening using HPV DNA genotyping had the greatest increase in costs. Repeat screening with HPV DNA testing was the most effective strategy below the willingness to pay threshold (ICER: $3,194/DALY averted). One-time screening with HPV DNA testing was also an efficient strategy (ICER: $1,398/DALY averted).

Conclusions

Repeat single-visit screening with HPV DNA testing was the optimal strategy simulated. Single-visit strategies with increased frequency for WLHIV may be cost-effective in KwaZulu-Natal and similar settings with high HIV and HPV prevalence.

Facility-Based Indicators to Manage and Scale Up Cervical Cancer Prevention and Care Services for Women Living With HIV in Sub-Saharan Africa: a Three-Round Online Delphi Consensus Method

BACKGROUND

Of women with cervical cancer (CC) and HIV, 85% live in sub-Saharan Africa, where 21% of all CC cases are attributable to HIV infection. We aimed to generate internationally acceptable facility-based indicators to monitor and guide scale up of CC prevention and care services offered on-site or off-site by HIV clinics.

METHODS

We reviewed the literature and extracted relevant indicators, grouping them into domains along the CC control continuum. From February 2021 to March 2022, we conducted a three-round, online Delphi process to reach consensus on indicators. We invited 106 experts to participate. Through an anonymous, iterative process, participants adapted the indicators to their context (round 1), then rated them for 5 criteria on a 5-point Likert-type scale (rounds 2 and 3) and then ranked their importance (round 3).

RESULTS

We reviewed 39 policies from 21 African countries and 7 from international organizations; 72 experts from 15 sub-Saharan Africa countries or international organizations participated in our Delphi process. Response rates were 34% in round 1, 40% in round 2, and 44% in round 3. Experts reached consensus for 17 indicators in the following domains: primary prevention (human papillomavirus prevention, n = 2), secondary prevention (screening, triage, treatment of precancerous lesions, n = 11), tertiary prevention (CC diagnosis and care, n = 2), and long-term impact of the program and linkage to HIV service (n = 2).

CONCLUSION

We recommend that HIV clinics that offer CC control services in sub-Saharan Africa implement the 17 indicators stepwise and adapt them to context to improve monitoring along the CC control cascade.

Preventing tuberculosis with community-based care in an HIV-endemic setting: a modeling analysis

Introduction

Antiretroviral therapy (ART) and TB preventive treatment (TPT) both prevent tuberculosis (TB) disease and deaths among people living with HIV. Differentiated care models, including community-based care, can increase uptake of ART and TPT to prevent TB in settings with a high burden of HIV-associated TB, particularly among men.

Methods

We developed a gender-stratified dynamic model of TB and HIV transmission and disease progression among 100,000 adults ages 15-59 in KwaZulu-Natal, South Africa. We drew model parameters from a community-based ART initiation and resupply trial in sub-Saharan Africa (Delivery Optimization for Antiretroviral Therapy, DO ART) and other scientific literature. We simulated the impacts of community-based ART and TPT care programs during 2018-2027, assuming that community-based ART and TPT care were scaled up to similar levels as in the DO ART trial (i.e., ART coverage increasing from 49% to 82% among men and from 69% to 83% among women) and sustained for ten years. We projected the number of TB cases, deaths, and disability-adjusted life years (DALYs) averted relative to standard, clinic-based care. We calculated program costs and incremental cost-effectiveness ratios from the provider perspective.

Results

If community-based ART care could be implemented with similar effectiveness to the DO ART trial, increased ART coverage could reduce TB incidence by 27.0% (range 21.3% - 34.1%) and TB mortality by 36.0% (range 26.9% - 43.8%) after ten years. Increasing both ART and TPT uptake through community-based ART with TPT care could reduce TB incidence by 29.7% (range 23.9% - 36.0%) and TB mortality by 36.0% (range 26.9% - 43.8%). Community-based ART with TPT care reduced gender disparities in TB mortality rates by reducing TB mortality among men by a projected 39.8% (range 32.2% - 46.3%) and by 30.9% (range 25.3% - 36.5%) among women. Over ten years, the mean cost per DALY averted by community-based ART with TPT care was $846 USD (range $709 - $1,012).

Conclusions

By substantially increasing coverage of ART and TPT, community-based care for people living with HIV could reduce TB incidence and mortality in settings with high burdens of HIV-associated TB and reduce TB gender disparities.

An audit of adherence to cervical cancer screening guidelines in a tertiary-level HIV clinic

Background

Cervical cancer is the most common malignancy affecting South African women aged 15-44 years, with a higher prevalence among women living with HIV (WLWH). Despite recommendations for a screening target of 70%, the reported rate of cervical cancer screening in South Africa is 19.3%.

Objectives

To investigate the adherence of healthcare workers to cervical cancer screening guidelines in a tertiary-level HIV clinic.

Method

A retrospective cross-sectional record audit of women attending the Charlotte Maxeke Johannesburg Academic Hospital HIV Clinic over a 1-month period.

Results

Out of 403 WLWH who attended the clinic, 180 (44.7%) were screened for cervical cancer in the 3 years prior to the index consultation. Only 115 (51.6%) of those women with no record of prior screening were subsequently referred for screening. Women who had undergone screening in the previous 3 years were significantly older (47 years vs 44 years, P = 0.046) and had a longer time since diagnosis of their HIV (12 years vs 10 years, P = 0.001) compared to women who had not undergone screening. There was no significant difference in CD4 count or viral suppression between women who had and had not undergone screening.

Conclusion

The rate of cervical cancer screening in our institution is below that recommended by the World Health Organization and the South African National Department of Health.