Cost-Effectiveness of Community-Based TB/HIV Screening and Linkage to Care in Rural South Africa

The impact of ethical implications intertwined with tuberculosis household contact investigation: a qualitative study

Background

Household contact investigation (HCI) is an effective and widely used approach to identify persons with tuberculosis (TB) disease and infection, globally. Despite widespread recommendations for the use of HCI, there remains poor understanding of the impact on and value of contact investigation for participants. Further, how HCI as a practice impacts psychosocial factors, including stigma and possible unintended disclosure of illness among persons with TB, their families, and communities, is largely unknown.

Methods

This exploratory qualitative study nested within a randomized trial (ClinicalTrials.gov: NCT04520113, 17 August 2020) was conducted in South Africa to understand the impacts of HCI on index patients living with TB and their household contact persons in two rural districts in the Limpopo province (Vhembe and Capricorn) and Soshanguve, a peri-urban township in Gauteng province. People with TB and household members of people with TB were recruited to participate in in-depth interviews and focus group discussions using semi-structured guides. We explored individual, interpersonal, and community-level perceptions of potential impacts of household contact investigation to elucidate their perceptions of HCI. Thematic analysis identified key themes.

Results

Twenty-four individual interviews and six focus group discussions (n=39 participants) were conducted. Participants viewed HCI as an effective approach to finding TB cases, helpful in educating households about TB symptoms and reducing barriers to health-related services. At the interpersonal level, HCI aided people with TB in safely disclosing their TB status to family members and facilitated family and social support for accountability. The introduction of HIV testing during HCI was reported by some participants as making household members slightly uncomfortable, decreasing interest in household members being tested for TB. HCI negatively impacted community-level TB and HIV-related stigma due to healthcare worker visibility at home.

Conclusion

Our data suggests varying impacts of HCI on people with TB, their families and interpersonal relationships, and communities, highlighting the importance of considering approaches that address concerns about community stigma and HIV testing to enhance acceptance of HCI.

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.

Modelling Methods of Economic Evaluations of HIV Testing Strategies in Sub-Saharan Africa: A Systematic Review

BACKGROUND AND OBJECTIVE

Economic evaluations, a decision-support tool for policy makers, will be crucial in planning and tailoring HIV prevention and treatment strategies especially in the wake of stalled and decreasing funding for the global HIV response. As HIV testing and treatment coverage increase, case identification becomes increasingly difficult and costly. Determining which subset of the population these strategies should be targeted to becomes of vital importance as well. Generating quality economic evidence begins with the validity of the modelling approach and the model structure employed. This study synthesises and critiques the reporting around modelling methodology of economic models in the evaluation of HIV testing strategies in sub-Saharan Africa.

METHODS

The following databases were searched from January 2000 to September 2020: MEDLINE, Embase, Scopus, EconLit and Global Health. Any model-based economic evaluation of a unique HIV testing strategy conducted in sub-Saharan Africa presenting a cost-effectiveness measure published from 2013 onwards was eligible. Data were extracted around three components: general study characteristics; economic evaluation design; and quality of model reporting using a novel tool developed for the purposes of this study.

RESULTS

A total of 21 studies were included; 10 cost-effectiveness analyses, 11 cost-utility analyses. All but one study was conducted in Eastern and Southern Africa. Modelling approaches for HIV testing strategies can be broadly characterised as static aggregate models (3/21), static individual models (6/21), dynamic aggregate models (5/21) and dynamic individual models (7/21). Adequate reporting around data handling was the highest of the three categories assessed (74%), and model validation, the lowest (45%). Limitations to model structure, justification of chosen time horizon and cycle length, and description of external model validation process were all adequately reported in less than 40% of studies. The predominant limitation of this review relates to the potential implications of the narrow inclusion criteria.

CONCLUSIONS

This review is the first to synthesise economic evaluations of HIV testing strategies in sub-Saharan Africa. The majority of models exhibited dynamic, stochastic and individual properties. Model reporting against the 13 criteria in our novel tool was mixed. Future model-based economic evaluations of HIV testing strategies would benefit from transparency around the choice of modelling approach, model structure, data handling procedures and model validation techniques.

Impact of interventions for tuberculosis prevention and care in South Africa - a systematic review of mathematical modelling studies

BACKGROUND

Substantial additional efforts are needed to prevent, find and successfully treat tuberculosis (TB) in South Africa (SA). In thepast decade, an increasing body of mathematical modelling research has investigated the population-level impact of TB prevention and careinterventions. To date, this evidence has not been assessed in the SA context.

OBJECTIVE

To systematically review mathematical modelling studies that estimated the impact of interventions towards the World HealthOrganization's End TB Strategy targets for TB incidence, TB deaths and catastrophic costs due to TB in SA.

METHODS

We searched the PubMed, Web of Science and Scopus databases for studies that used transmission-dynamic models of TB in SAand reported on at least one of the End TB Strategy targets at population level. We described study populations, type of interventions andtheir target groups, and estimates of impact and other key findings. For studies of country-level interventions, we estimated average annualpercentage declines (AAPDs) in TB incidence and mortality attributable to the intervention.

RESULTS

We identified 29 studies that met our inclusion criteria, of which 7 modelled TB preventive interventions (vaccination,antiretroviral treatment (ART) for HIV, TB preventive treatment (TPT)), 12 considered interventions along the care cascade for TB(screening/case finding, reducing initial loss to follow-up, diagnostic and treatment interventions), and 10 modelled combinationsof preventive and care-cascade interventions. Only one study focused on reducing catastrophic costs due to TB. The highest impactof a single intervention was estimated in studies of TB vaccination, TPT among people living with HIV, and scale-up of ART. Forpreventive interventions, AAPDs for TB incidence varied between 0.06% and 7.07%, and for care-cascade interventions between 0.05%and 3.27%.

CONCLUSION

We describe a body of mathematical modelling research with a focus on TB prevention and care in SA. We found higherestimates of impact reported in studies of preventive interventions, highlighting the need to invest in TB prevention in SA. However, studyheterogeneity and inconsistent baseline scenarios limit the ability to compare impact estimates between studies. Combinations, rather thansingle interventions, are likely needed to reach the End TB Strategy targets in SA.

Costs and cost-effectiveness of HIV counselling and testing modalities in Southern Mozambique

Objective

Despite the high HIV associated burden, Mozambique lacks data on HIV counselling and testing (HCT) costs. To help guide national HIV/AIDS programs, we estimated the cost per test for voluntary counselling and testing (VCT) from the patient’s perspective and the costs per person tested and per HIV-positive individual linked to care to the healthcare provider for VCT, provider-initiated counselling and testing (PICT) and home-based testing (HBT). We also assessed the cost-effectiveness of these strategies for linking patients to care.

Methods

Data from a cohort study conducted in the Manhiça District were used to derive costs and linkage-to-care outcomes of the three HCT strategies. A decision tree was used to model HCT costs according to the likelihood of HCT linking individuals to care and to obtain the incremental cost-effectiveness ratios (ICERs) of PICT and HBT with VCT as the comparator. Sensitivity analyses were performed to assess robustness of base-case findings.

Findings

Based on costs and valuations in 2015, average and median VCT costs to the patient per individual tested were US$1.34 and US$1.08, respectively. Costs per individual tested were greatest for HBT (US$11.07), followed by VCT (US$7.79), and PICT (US$7.14). The costs per HIV-positive individual linked to care followed a similar trend. PICT was not cost-effective in comparison with VCT at a willingness-to-accept threshold of US$4.53, but only marginally given a corresponding base-case ICER of US$4.15, while HBT was dominated, with higher costs and lower impact than VCT. Base-case results for the comparison between PICT and VCT presented great uncertainty, whereas findings for HBT were robust.

Conclusion

PICT and VCT are likely equally cost-effective in Manhiça. We recommend that VCT be offered as the predominant HCT strategy in Mozambique, but expansion of PICT could be considered in limited-resource areas. HBT without facilitated linkage or reduced costs is unlikely to be cost-effective.

Community-based referral for tuberculosis preventive therapy is effective for treatment completion

Expansion of tuberculous preventive therapy (TPT) is essential to curb TB incidence and mortality among people with HIV (PWH), yet implementation has been slow. Innovative strategies to operationalize TPT are urgently needed. Here we present an evaluation of community-based identification and referral of PWH on completion of a six-month course of isoniazid in a highly prevalent region in rural South Africa. Using a community-based TB/HIV intensive case finding strategy, a team of nurses and lay workers identified community members with HIV who were without fever, night sweats, weight loss, or cough and referred them to the government primary care clinics for daily oral isoniazid, the only available TPT regimen. We measured monthly adherence and six-month treatment completion in the community-based identification and referral (CBR) group compared to those already engaged in HIV care. Adherence was measured by self-report and urine isoniazid metabolite testing. A multivariable analysis was performed to identify independent predictors of TPT completion. Among 240 participants, 81.7% were female, median age 35 years (IQR 30-44), and 24.6% had previously been treated for TB. The median CD4 count in the CBR group was 457 (IQR 301-648), significantly higher than the clinic-based comparison group median CD4 of 344 (IQR 186-495, p<0.001). Independent predictors of treatment completion included being a woman (aOR 2.41, 95% 1.02-5.72) and community-based identification and referral for TPT (aOR 2.495, 95% 1.13-5.53). Among the CBR group, treatment completion was 90.0%, an absolute 10.8% higher than the clinic-based comparison group (79.2%, p = 0.02). Adherence was significantly greater in the CBR group than the clinic-based comparison group, as measured by self-report (p = 0.02) and urine isoniazid testing (p = 0.01). Among those not on ART at baseline, 10% of eligible PWH subsequently initiated ART. Community members living with HIV in TB endemic regions identified and referred for TPT demonstrated higher treatment completion and adherence compared to PWH engaged for TPT while receiving clinic-based care. Community-based identification and referral is an innovative adjunctive strategy to facilitate implementation of TB preventive therapy in people living with HIV.

Linkage to TB care: A qualitative study to understand linkage from the patients' perspective in the Western Cape Province, South Africa

BACKGROUND

Delayed linkage to tuberculosis (TB) treatment leads to poor patient outcomes and increased onward transmission. Between 12% and 25% of people diagnosed with TB are never linked to a primary health care facility for continued care. The TB health program is for creating processes that promote and facilitates easy access to care. We explored how TB patients experience TB services and how this influenced their choices around linkage to TB care and treatment.

METHODS

We enrolled 20 participants routinely diagnosed with TB in hospital or at primary health care facilities (PHC) in a high TB/HIV burdened peri-urban community in South Africa. Using the Western Cape Provincial Health Data centre (PHDC) which consolidates person-level clinical data, we used dates of diagnosis and treatment initiation to select participants who had been linked (immediately, after a delay, or never). Between June 2019 and January 2020, we facilitated in-depth discussions to explore both the participants' experience of their TB diagnosis and their journey around linking to TB care at a primary health care facility. We analysed the data using case descriptions.

RESULTS

Twelve of twenty (12/20) participants interviewed who experienced a delay linking were diagnosed at the hospital. Participants who experienced delays in linking or never linked explained this as a result of lack of information and support from health care providers. Unpleasant previous TB treatment episodes made it difficult to 'face' TB again and being uncertain of their TB diagnosis. In contrast, participants said the main motivator for linking was a personal will to get better.

CONCLUSION

The health care system, especially in hospitals, should focus on strengthening patient-centred care. Communication and clear messaging on TB processes is key, to prepare patients in transitioning from a hospital setting to PHC facilities for continuation of care. This should not just include a thorough explanation of their TB diagnosis but ensure that patients understand treatment processes. Former TB patients may require additional counselling and support to re-engage in care.

Costs and cost-effectiveness of a comprehensive tuberculosis case finding strategy in Zambia

Introduction

Active-case finding (ACF) programs have an important role in addressing case detection gaps and halting tuberculosis (TB) transmission. Evidence is limited on the cost-effectiveness of ACF interventions, particularly on how their value is impacted by different operational, epidemiological and patient care-seeking patterns.

Methods

We evaluated the costs and cost-effectiveness of a combined facility and community-based ACF intervention in Zambia that utilized mobile chest X-ray with computer-aided reading/interpretation software and laboratory-based Xpert MTB/RIF testing. Programmatic costs (in 2018 US dollars) were assessed from the health system perspective using prospectively collected cost and operational data. Cost-effectiveness of the ACF intervention was assessed as the incremental cost per TB death averted over a five-year time horizon using a multi-stage Markov state-transition model reflecting patient symptom-associated care-seeking and TB care under ACF compared to passive care.

Results

Over 18 months of field operations, the ACF intervention costed $435 to diagnose and initiate treatment for one person with TB. After accounting for patient symptom-associated care-seeking patterns in Zambia, we estimate that this one-time ACF intervention would incrementally diagnose 407 (7,207 versus 6,800) TB patients and avert 502 (611 versus 1,113) TB-associated deaths compared to the status quo (passive case finding), at an incremental cost of $2,284 per death averted over the next five-year period. HIV/TB mortality rate, patient symptom-associated care-seeking probabilities in the absence of ACF, and the costs of ACF patient screening were key drivers of cost-effectiveness.

Conclusions

A one-time comprehensive ACF intervention simultaneously operating in public health clinics and corresponding catchment communities can have important medium-term impact on case-finding and be cost-effective in Zambia. The value of such interventions increases if targeted to populations with high HIV/TB mortality, substantial barriers (both behavioral and physical) to care-seeking exist, and when ACF interventions can optimize screening by achieving operational efficiency.

Economic and modeling evidence for tuberculosis preventive therapy among people living with HIV: A systematic review and meta-analysis

BACKGROUND

Human immunodeficiency virus (HIV) is the strongest known risk factor for tuberculosis (TB) through its impairment of T-cell immunity. Tuberculosis preventive treatment (TPT) is recommended for people living with HIV (PLHIV) by the World Health Organization, as it significantly reduces the risk of developing TB disease. We conducted a systematic review and meta-analysis of modeling studies to summarize projected costs, risks, benefits, and impacts of TPT use among PLHIV on TB-related outcomes.

METHODS AND FINDINGS

We searched MEDLINE, Embase, and Web of Science from inception until December 31, 2020. Two reviewers independently screened titles, abstracts, and full texts; extracted data; and assessed quality. Extracted data were summarized using descriptive analysis. We performed quantile regression and random effects meta-analysis to describe trends in cost, effectiveness, and cost-effectiveness outcomes across studies and identified key determinants of these outcomes. Our search identified 6,615 titles; 61 full texts were included in the final review. Of the 61 included studies, 31 reported both cost and effectiveness outcomes. A total of 41 were set in low- and middle-income countries (LMICs), while 12 were set in high-income countries (HICs); 2 were set in both. Most studies considered isoniazid (INH)-based regimens 6 to 2 months long (n = 45), or longer than 12 months (n = 11). Model parameters and assumptions varied widely between studies. Despite this, all studies found that providing TPT to PLHIV was predicted to be effective at averting TB disease. No TPT regimen was substantially more effective at averting TB disease than any other. The cost of providing TPT and subsequent downstream costs (e.g. post-TPT health systems costs) were estimated to be less than $1,500 (2020 USD) per person in 85% of studies that reported cost outcomes (n = 36), regardless of study setting. All cost-effectiveness analyses concluded that providing TPT to PLHIV was potentially cost-effective compared to not providing TPT. In quantitative analyses, country income classification, consideration of antiretroviral therapy (ART) use, and TPT regimen use significantly impacted cost-effectiveness. Studies evaluating TPT in HICs suggested that TPT may be more effective at preventing TB disease than studies evaluating TPT in LMICs; pooled incremental net monetary benefit, given a willingness-to-pay threshold of country-level per capita gross domestic product (GDP), was $271 in LMICs (95% confidence interval [CI] -$81 to $622, p = 0.12) and was $2,568 in HICs (-$32,115 to $37,251, p = 0.52). Similarly, TPT appeared to be more effective at averting TB disease in HICs; pooled percent reduction in active TB incidence was 20% (13% to 27%, p < 0.001) in LMICs and 37% (-34% to 100%, p = 0.13) in HICs. Key limitations of this review included the heterogeneity of input parameters and assumptions from included studies, which limited pooling of effect estimates, inconsistent reporting of model parameters, which limited sample sizes of quantitative analyses, and database bias toward English publications.

CONCLUSIONS

The body of literature related to modeling TPT among PLHIV is large and heterogeneous, making comparisons across studies difficult. Despite this variability, all studies in all settings concluded that providing TPT to PLHIV is potentially effective and cost-effective for preventing TB disease.

Cost-Effectiveness Analysis of High-Risk Groups Tuberculosis Screening in Malaysia

Screening of high-risk groups for Tuberculosis (TB) is considered as the cornerstone for TB elimination but the measure of cost-effectiveness is also crucial in deciding the strategy for TB screening. This study aims to measure the cost-effectiveness of TB screening between the various high-risk groups in Malaysia. A decision tree model was developed to assess the cost-effectiveness of TB screening among the high-risk groups from a provider perspective using secondary data from the year 2016 to 2018. The results are presented in terms of an Incremental Cost-Effectiveness Ratio (ICER), expressed as cost per TB case detected. Deterministic and Probabilistic Sensitivity Analysis was also performed to measure the robustness of the model. TB screening among Person Living with Human Immunodeficiency Virus (PL HIV) was the most cost-effective strategy, with MYR 2,597.00 per TB case detected. This was followed by elderly, prisoners and smokers with MYR 2,868.62, MYR 3,065.24, and MYR 4,327.76 per one TB case detected, respectively. There was an incremental cost of MYR 2.49 per screening, and 3.4 TB case detection per 1,000 screening for TB screening among PL HIV in relation to TB screening among prisoners. The probability of symptomatic cases diagnosed as TB was the key driver for increasing cost-effectiveness efficacy among PL HIV. Results of the study suggest prioritization of high-risk group TB screening program by focusing on the most cost-effective strategy such as screening among PL HIV, prisoners and elderly, which has a lower cost per TB case detected.

Cost and cost-effectiveness of a universal HIV testing and treatment intervention in Zambia and South Africa: evidence and projections from the HPTN 071 (PopART) trial

BACKGROUND

The HPTN 071 (PopART) trial showed that a combination HIV prevention package including universal HIV testing and treatment (UTT) reduced population-level incidence of HIV compared with standard care. However, evidence is scarce on the costs and cost-effectiveness of such an intervention.

METHODS

Using an individual-based model, we simulated the PopART intervention and standard care with antiretroviral therapy (ART) provided according to national guidelines for the 21 trial communities in Zambia and South Africa (for all individuals aged >14 years), with model parameters and primary cost data collected during the PopART trial and from published sources. Two intervention scenarios were modelled: annual rounds of PopART from 2014 to 2030 (PopART 2014-30; as the UNAIDS Fast-Track target year) and three rounds of PopART throughout the trial intervention period (PopART 2014-17). For each country, we calculated incremental cost-effectiveness ratios (ICERs) as the cost per disability-adjusted life-year (DALY) and cost per HIV infection averted. Cost-effectiveness acceptability curves were used to indicate the probability of PopART being cost-effective compared with standard care at different thresholds of cost per DALY averted. We also assessed budget impact by projecting undiscounted costs of the intervention compared with standard care up to 2030.

FINDINGS

During 2014-17, the mean cost per person per year of delivering home-based HIV counselling and testing, linkage to care, promotion of ART adherence, and voluntary medical male circumcision via community HIV care providers for the simulated population was US$6·53 (SD 0·29) in Zambia and US$7·93 (0·16) in South Africa. In the PopART 2014-30 scenario, median ICERs for PopART delivered annually until 2030 were $2111 (95% credible interval [CrI] 1827-2462) per HIV infection averted in Zambia and $3248 (2472-3963) per HIV infection averted in South Africa; and $593 (95% CrI 526-674) per DALY averted in Zambia and $645 (538-757) per DALY averted in South Africa. In the PopART 2014-17 scenario, PopART averted one infection at a cost of $1318 (1098-1591) in Zambia and $2236 (1601-2916) in South Africa, and averted one DALY at $258 (225-298) in Zambia and $326 (266-391) in South Africa, when outcomes were projected until 2030. The intervention had almost 100% probability of being cost-effective at thresholds greater than $700 per DALY averted in Zambia, and greater than $800 per DALY averted in South Africa, in the PopART 2014-30 scenario. Incremental programme costs for annual rounds until 2030 were $46·12 million (for a mean of 341 323 people) in Zambia and $30·24 million (for a mean of 165 852 people) in South Africa.

INTERPRETATION

Combination prevention with universal home-based testing can be delivered at low annual cost per person but accumulates to a considerable amount when scaled for a growing population. Combination prevention including UTT is cost-effective at thresholds greater than $800 per DALY averted and can be an efficient strategy to reduce HIV incidence in high-prevalence settings.

FUNDING

US National Institutes of Health, President's Emergency Plan for AIDS Relief, International Initiative for Impact Evaluation, Bill & Melinda Gates Foundation.

Diagnosis and treatment outcomes of adult tuberculosis in an urban setting with high HIV prevalence in Sierra Leone: A retrospective study

OBJECTIVE

To assess the diagnosis, treatment outcomes, and predictors of mortality in adult tuberculosis (TB) patients in an urban setting with a high HIV prevalence.

METHODS

A retrospective study was conducted of adult TB patients aged ≥15 years who were treated at Connaught Hospital in Freetown, Sierra Leone from January through December 2017. Multivariate logistic regression was used to identify predictors of mortality.

RESULTS

Of 1127 TB cases notified in 2017, 1105 (98%) were tested for HIV, yielding a TB/HIV co-infection rate of 32.0%. Only HIV-tested cases (n=1105) were included in the final analysis. The majority were male (69.3%), aged 25-34 years (29.2%), and had pulmonary TB (96.3%). Treatment outcomes were as follows: 29.0% cured, 29.0% completed, 0.5% treatment failure, 24.2% lost to follow-up, 12.8% transferred/not evaluated, and 4.5% died. The majority of deaths (80.0%, 40/50) occurred within 2 months of TB treatment initiation. Age 65 years or older (adjusted odds ratio 3.48, 95% confidence interval 1.15-10.56; p=0.027) and HIV-positive status (adjusted odds ratio 3.50, 95% confidence interval 1.72-7.12; p=0.001) were independent predictors of mortality.

CONCLUSIONS

Suboptimal TB treatment outcomes were observed in Sierra Leone in 2017. More local and international action is warranted to help achieve the 2035 global TB elimination targets.

Opportunities for community health workers to contribute to global efforts to end tuberculosis

Tuberculosis (TB) has emerged as the leading infectious cause of death globally. New paradigms are needed to reduce TB rates and mortality. Programs harnessing the potential of community health workers (CHWs) to enhance TB prevention and care have shown great promise. In this perspective article, we review the history of CHW-based efforts to prevent and treat TB, present evidence illustrating the effectiveness of CHWs across the entire cascade of TB care, and outline additional opportunities for CHWs to address challenges particular to the TB pandemic. Despite many promising studies, knowledge gaps persist and we suggest an agenda for future research on the role of CHWs in TB prevention and care.

Synergism between diabetes and human immunodeficiency virus in increasing the risk of tuberculosis

SETTING

Community health screenings in KwaZulu-Natal Province, South Africa.

OBJECTIVE

To study the synergism between diabetes mellitus (DM) and human immunodeficiency virus (HIV) infection in increasing the risk of tuberculosis (TB).

DESIGN

In this cross-sectional study, we analyzed data from two community health projects, one at congregate settings, and one at household settings (n = 7708), in a rural resource-limited region where integrated communicable and non-communicable disease screening services were offered. Odds ratios (ORs) for demographic factors, socio-economic factors, DM status, and HIV positivity were calculated using multivariate analysis, and the statistical interaction between HIV and DM was tested. The primary outcome was the presence of TB symptoms.

RESULTS

Among 7708 individuals, age >65 years (OR 1.72, 95%CI 1.47-2.02), HIV infection (OR 1.66, 95%CI 1.40-1.97) and DM (OR 1.36, 95%CI 1.11-1.67) were independently associated with increased odds of TB symptoms. Receiving monthly grants (OR 0.78, 95%CI 0.66-0.91), access to a toilet (OR 0.54, 95%CI 0.35-0.83), and access to solar or electric energy (OR 0.86, 95%CI 0.77-0.97) reduced the odds. There was evidence of significant interaction between DM and HIV on the multiplicative scale.

CONCLUSION

DM and HIV synergistically increased the odds of TB symptoms according to these retrospective data. Future studies should prospectively evaluate synergism between HIV and DM in increasing the risk of active TB.

Population-level mathematical modeling of antimicrobial resistance: a systematic review

BACKGROUND

Mathematical transmission models are increasingly used to guide public health interventions for infectious diseases, particularly in the context of emerging pathogens; however, the contribution of modeling to the growing issue of antimicrobial resistance (AMR) remains unclear. Here, we systematically evaluate publications on population-level transmission models of AMR over a recent period (2006-2016) to gauge the state of research and identify gaps warranting further work.

METHODS

We performed a systematic literature search of relevant databases to identify transmission studies of AMR in viral, bacterial, and parasitic disease systems. We analyzed the temporal, geographic, and subject matter trends, described the predominant medical and behavioral interventions studied, and identified central findings relating to key pathogens.

RESULTS

We identified 273 modeling studies; the majority of which (> 70%) focused on 5 infectious diseases (human immunodeficiency virus (HIV), influenza virus, Plasmodium falciparum (malaria), Mycobacterium tuberculosis (TB), and methicillin-resistant Staphylococcus aureus (MRSA)). AMR studies of influenza and nosocomial pathogens were mainly set in industrialized nations, while HIV, TB, and malaria studies were heavily skewed towards developing countries. The majority of articles focused on AMR exclusively in humans (89%), either in community (58%) or healthcare (27%) settings. Model systems were largely compartmental (76%) and deterministic (66%). Only 43% of models were calibrated against epidemiological data, and few were validated against out-of-sample datasets (14%). The interventions considered were primarily the impact of different drug regimens, hygiene and infection control measures, screening, and diagnostics, while few studies addressed de novo resistance, vaccination strategies, economic, or behavioral changes to reduce antibiotic use in humans and animals.

CONCLUSIONS

The AMR modeling literature concentrates on disease systems where resistance has been long-established, while few studies pro-actively address recent rise in resistance in new pathogens or explore upstream strategies to reduce overall antibiotic consumption. Notable gaps include research on emerging resistance in Enterobacteriaceae and Neisseria gonorrhoeae; AMR transmission at the animal-human interface, particularly in agricultural and veterinary settings; transmission between hospitals and the community; the role of environmental factors in AMR transmission; and the potential of vaccines to combat AMR.

Is palliative care cost-effective in low-income and middle-income countries? A mixed-methods systematic review

Introduction

Of the 40 million people globally in need of palliative care (PC), just 14% receive it, predominantly in high-income countries. Within fragile health systems that lack PC, incurable illness is often marked by pain and suffering, as well as burdensome costs. In high-income settings, PC decreases healthcare utilisation, thus enhancing value. Similar cost-effectiveness models are lacking in low-income and middle-income countries and with them, the impetus and funding to expand PC delivery.

Methods

We conducted a systematic search of seven databases to gather evidence of the cost-effectiveness of PC in low-income and middle-income countries. We extracted and synthesised palliative outcomes and economic data from original research studies occurring in low-income and middle-income countries. This review adheres to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and includes a quality appraisal.

Results

Our search identified 10 eligible papers that included palliative and economic outcomes in low-income and middle-income countries. Four provided true cost-effectiveness analyses in comparing the costs of PC versus alternative care, with PC offering cost savings, favourable palliative outcomes and positive patient-reported and family-reported outcomes.

Conclusions

Despite the small number of included studies, wide variety of study types and lack of high-quality studies, several patterns emerged: (1) low-cost PC delivery in low-income and middle-income countries is possible, (2) patient-reported outcomes are favourable and (3) PC is less costly than the alternative. This review highlights the extraordinary need for robust cost-effectiveness analysis of PC in low-income and middle-income countries in order to develop health economic models for the delivery of PC, direct resource allocation and guide healthcare policy for PC delivery in low-income and middle-income countries.

The investment case for hepatitis B and C in South Africa: adaptation and innovation in policy analysis for disease program scale-up

Even though WHO has approved global goals for hepatitis elimination, most countries have yet to establish programs for hepatitis B and C, which account for 320 million infections and over a million deaths annually. One reason for this slow response is the paucity of robust, compelling analyses showing that national HBV/HCV programs could have a significant impact on these epidemics and save lives in a cost-effective, affordable manner. In this context, our team used an investment case approach to develop a national hepatitis action plan for South Africa, grounded in a process of intensive engagement of local stakeholders. Costs were estimated for each activity using an ingredients-based, bottom-up costing tool designed by the authors. The health impact and cost-effectiveness of the Action Plan were assessed by simulating its four priority interventions (HBV birth dose vaccination, PMTCT, HBV treatment and HCV treatment) using previously developed models calibrated to South Africa's demographic and epidemic profile. The Action Plan is estimated to require ZAR3.8 billion (US$294 million) over 2017-2021, about 0.5% of projected government health spending. Treatment scale-up over the initial 5-year period would avert 13 000 HBV-related and 7000 HCV-related deaths. If scale up continues beyond 2021 in line with WHO goals, more than 670 000 new infections, 200 000 HBV-related deaths, and 30 000 HCV-related deaths could be averted. The incremental cost-effectiveness of the Action Plan is estimated at $3310 per DALY averted, less than the benchmark of half of per capita GDP. Our analysis suggests that the proposed scale-up can be accommodated within South Africa's fiscal space and represents good use of scarce resources. Discussions are ongoing in South Africa on the allocation of budget to hepatitis. Our work illustrates the value and feasibility of using an investment case approach to assess the costs and relative priority of scaling up HBV/HCV services.

Integrated Tuberculosis/Human Immunodeficiency Virus Community-Based Case Finding in Rural South Africa: Implications for Tuberculosis Control Efforts

Background

Intensive case finding is endorsed for tuberculosis (TB) control in high-risk populations. Novel case-finding strategies are needed in hard-to-reach rural populations with high prevalence of TB and human immunodeficiency virus (HIV).

Methods

We performed community-based integrated HIV and TB intensive case finding in a rural South African subdistrict from March 2010 to June 2012. We offered TB symptom screening, sputum collection for microbiologic diagnosis, rapid fingerstick HIV testing, and phlebotomy for CD4 cell count. We recorded number of cases detected and calculated population-level rates and number needed to screen (NNS) for drug-susceptible and -resistant TB.

Results

Among 5615 persons screened for TB at 322 community sites, 91.2% accepted concurrent HIV testing, identifying 510 (9.9%) HIV-positive individuals with median CD4 count of 382 cells/mm³ (interquartile range = 260–552). Tuberculosis symptoms were reported by 2049 (36.4%), and sputum was provided by 1033 (18.4%). Forty-one (4.0%) cases of microbiologically confirmed TB were detected for an overall case notification rate of 730/100000 (NNS = 137); 11 (28.6%) were multidrug-resistant or extensively drug-resistant TB. Only 5 (12.2%) TB cases were HIV positive compared with an HIV coinfection rate of 64% among contemporaneously registered TB cases (P = .001).

Conclusion

Community-based integrated intensive case finding is feasible and is high yield for drug-susceptible and -resistant TB and HIV in rural South Africa. Human immunodeficiency virus–negative tuberculosis predominated in this community sample, suggesting a distinct TB epidemiology compared with cases diagnosed in healthcare facilities. Increasing HIV/TB integrated community-based efforts and other strategies directed at both HIV-positive and HIV-negative tuberculosis may contribute to TB elimination in high TB/HIV burden regions.