Rapid diagnosis of tuberculosis with the Xpert MTB/RIF assay in high burden countries: a cost-effectiveness analysis

Comparing the cost-effectiveness of the MPT64-antigen detection test to Xpert MTB/RIF and ZN-microscopy for the diagnosis of Extrapulmonary Tuberculosis: An economic evaluation modelling study

Extrapulmonary Tuberculosis (EPTB) poses challenges from patient and health system perspectives. The cost-effectiveness analysis of the Xpert MTB/RIF (Xpert) test to diagnose pulmonary tuberculosis is documented. However, there are no economic evaluations for EPTB. Considering the reported better diagnostic sensitivity of the MPT64 test, this study explored its cost-effectiveness as an alternative diagnostic test. We conducted this economic evaluation to assess the cost-effectiveness of the MPT64 test compared to Xpert and ZN microscopy for EPTB adult patients. We utilised a Markov modelling approach to capture short- and long-term costs and benefits from a health system perspective. For the model inputs, we combined data from our cohort studies in Tanzania and peer-reviewed EPTB literature. We calculated the Incremental Cost Effectiveness Ratio (ICER) by comparing the cost (in USD) of each diagnostic test and Quality Adjusted Life Years (QALYs) as health gain. We found the MPT64 test cost-effective for EPTB diagnosis and absolutely dominated ZN microscopy and Xpert using the baseline model inputs. A scenario analysis showed that the Xpert test might be the most cost-effective at its higher test sensitivity, which corresponds to using it to diagnose lymph node aspirates. The prevalence of HIV among EPTB cases, their probability of treatment, costs of ART, and the probability of the MPT64 test in detecting EPTB patients were the main parameters associated with the highest impact on ICER in one-way deterministic analysis. The most cost-effective option for EPTB at the baseline parameters was the MPT64 diagnostic test. Including the MPT64 test in EPTB diagnostic pathways for previously untreated patients can lead to better resource use. The Xpert test was the most cost-effective diagnostic intervention at a higher diagnostic test sensitivity in scenario analyses based on different sites of infection, such as for the lymph node aspirates.

Cost-effectiveness of TB diagnostic technologies in Ethiopia: a modelling study

BACKGROUND

Tuberculosis (TB) is a major threat to public health, particularly in countries where the disease is highly prevalent, such as Ethiopia. Early diagnosis and treatment are the main components of TB prevention and control. Although the national TB guideline recommends the primary use of rapid TB diagnostics whenever feasible, there is limited evidence available that assess the efficiency of deploying various diagnostic tools in the country. Hence, this study aims to evaluate the cost-effectiveness of rapid TB/MDR-TB diagnostic tools in Ethiopia.

METHODS

A hybrid Markov model for a hypothetical adult cohort of presumptive TB cases was constructed. The following TB diagnostic tools were evaluated: X-pert MTB/RIF, Truenat, chest X-ray screening followed by an X-pert MTB/RIF, TB-LAMP, and smear microscopy. Cost-effectiveness was determined based on incremental costs ($) per Disability-adjusted Life Years (DALY) averted, using a threshold of one times Gross Domestic Product (GDP) per capita ($856). Data on starting and transition probabilities, costs, and health state utilities were derived from secondary sources. The analysis is conducted from the health system perspective, and a probabilistic sensitivity analysis is performed.

RESULT

The incremental cost-effectiveness ratio for X-pert MTB/RIF, compared to the next best alternative, is $276 per DALY averted, making it a highly cost-effective diagnostic tool. Additionally, chest X-ray screening followed an X-pert MTB/RIF test is less cost-effective, with an ICER of $1666 per DALY averted. Introducing X-pert MTB/RIF testing would enhance TB detection and prevent 9600 DALYs in a cohort of 10,000 TB patients, with a total cost of $3,816,000.

CONCLUSION

The X-pert MTB/RIF test is the most cost-effective diagnostic tool compared to other alternatives. The use of this diagnostic tool improves the early detection and treatment of TB cases. Increased funding for this diagnostic tool will enhance access, reduce the TB detection gaps, and improve treatment outcomes.

The Role of GeneXpert® for Tuberculosis Diagnostics in Brazil: An Examination from a Historical and Epidemiological Perspective

The rapid molecular test (RMT) performed on the GeneXpert® system is widely used as a control strategy and surveillance technique for tuberculosis (TB). In the region of the Americas, TB incidence is slowly increasing owing to an upward trend in Brazil, which is among the high TB-burden countries (HBCs), ranking in the 19th position. In this context, we aimed to (i) describe the implementation and history of RMT-TB (Xpert® MTB/RIF and Xpert® MTB/RIF Ultra) in Brazil; (ii) to evaluate the national RMT laboratory distribution, TB, and resistance to RIF detection by RMT; and (iii) to correlate these data with Brazilian TB incidence. The quantitative data of Xpert® MTB/RIF and Xpert® MTB/RIF Ultra assays performed in the pulmonary TB investigation from 2014 to 2020 were provided by the Brazilian Ministry of Health. A spatial visualization using ArcGIS software was performed. The Southeast region constituted about half of the RMT laboratories-from 39.4% to 45.9% of the total value over the five regions. Regarding the federal units, the São Paulo state alone represented from 20.2% to 34.1% (5.0 to 8.5 times the value) of RMT laboratories over the years observed. There were significant differences (p < 0.0001) in the frequency of RMT laboratories between all years of the historical series. There was an unequal distribution of RMT laboratories between Brazilian regions and federal units. This alerts us for the surveillance of rapid molecular detection of TB in different parts of the country, with the possibility of improving the distribution of tests in areas of higher incidence in order to achieve the level of disease control recommended by national and worldwide authorities.

New tuberculosis vaccines in India: modelling the potential health and economic impacts of adolescent/adult vaccination with M72/AS01E and BCG-revaccination

BACKGROUND

India had an estimated 2.9 million tuberculosis cases and 506 thousand deaths in 2021. Novel vaccines effective in adolescents and adults could reduce this burden. M72/AS01E and BCG-revaccination have recently completed phase IIb trials and estimates of their population-level impact are needed. We estimated the potential health and economic impact of M72/AS01E and BCG-revaccination in India and investigated the impact of variation in vaccine characteristics and delivery strategies.

METHODS

We developed an age-stratified compartmental tuberculosis transmission model for India calibrated to country-specific epidemiology. We projected baseline epidemiology to 2050 assuming no-new-vaccine introduction, and M72/AS01E and BCG-revaccination scenarios over 2025-2050 exploring uncertainty in product characteristics (vaccine efficacy, mechanism of effect, infection status required for vaccine efficacy, duration of protection) and implementation (achieved vaccine coverage and ages targeted). We estimated reductions in tuberculosis cases and deaths by each scenario compared to the no-new-vaccine baseline, as well as costs and cost-effectiveness from health-system and societal perspectives.

RESULTS

M72/AS01E scenarios were predicted to avert 40% more tuberculosis cases and deaths by 2050 compared to BCG-revaccination scenarios. Cost-effectiveness ratios for M72/AS01E vaccines were around seven times higher than BCG-revaccination, but nearly all scenarios were cost-effective. The estimated average incremental cost was US$190 million for M72/AS01E and US$23 million for BCG-revaccination per year. Sources of uncertainty included whether M72/AS01E was efficacious in uninfected individuals at vaccination, and if BCG-revaccination could prevent disease.

CONCLUSIONS

M72/AS01E and BCG-revaccination could be impactful and cost-effective in India. However, there is great uncertainty in impact, especially given the unknowns surrounding the mechanism of effect and infection status required for vaccine efficacy. Greater investment in vaccine development and delivery is needed to resolve these unknowns in vaccine product characteristics.

Miniaturized Rapid Electrochemical Immunosensor Based on Screen Printed Carbon Electrodes for Mycobacterium tuberculosis Detection

In 2019, over 21% of an estimated 10 million new tuberculosis (TB) patients were either not diagnosed at all or diagnosed without being reported to public health authorities. It is therefore critical to develop newer and more rapid and effective point-of-care diagnostic tools to combat the global TB epidemic. PCR-based diagnostic methods such as Xpert MTB/RIF are quicker than conventional techniques, but their applicability is restricted by the need for specialized laboratory equipment and the substantial cost of scaling-up in low- and middle-income countries where the burden of TB is high. Meanwhile, loop-mediated isothermal amplification (LAMP) amplifies nucleic acids under isothermal conditions with a high efficiency, helps in the early detection and identification of infectious diseases, and can be performed without the need for sophisticated thermocycling equipment. In the present study, the LAMP assay was integrated with screen-printed carbon electrodes and a commercial potentiostat for real time cyclic voltammetry analysis (named as the LAMP-Electrochemical (EC) assay). The LAMP-EC assay was found to be highly specific to TB-causing bacteria and capable of detecting even a single copy of the Mycobacterium tuberculosis (Mtb) IS6110 DNA sequence. Overall, the LAMP-EC test developed and evaluated in the present study shows promise to become a cost-effective tool for rapid and effective diagnosis of TB.

On-Field Test of Tuberculosis Diagnosis through Exhaled Breath Analysis with a Gas Sensor Array

Tuberculosis (TB) is among the more frequent causes of death in many countries. For pulmonary TB, early diagnosis greatly increases the efficiency of therapies. Although highly sensitive tests based on nucleic acid amplification tests (NAATs) and loop-mediated isothermal amplification (TB-LAMP) are available, smear microscopy is still the most widespread diagnostics method in most low-middle-income countries, and the true positive rate of smear microscopy is lower than 65%. Thus, there is a need to increase the performance of low-cost diagnosis. For many years, the use of sensors to analyze the exhaled volatile organic compounds (VOCs) has been proposed as a promising alternative for the diagnosis of several diseases, including tuberculosis. In this paper, the diagnostic properties of an electronic nose (EN) based on sensor technology previously used to identify tuberculosis have been tested on-field in a Cameroon hospital. The EN analyzed the breath of a cohort of subjects including pulmonary TB patients (46), healthy controls (38), and TB suspects (16). Machine learning analysis of the sensor array data allows for the identification of the pulmonary TB group with respect to healthy controls with 88% accuracy, 90.8% sensitivity, 85.7% specificity, and 0.88 AUC. The model trained with TB and healthy controls maintains its performance when it is applied to symptomatic TB suspects with a negative TB-LAMP. These results encourage the investigation of electronic noses as an effective diagnostic method for future inclusion in clinical practice.

Modelling the impact of CD4 testing on mortality from TB and cryptococcal meningitis among patients with advanced HIV disease in nine countries

INTRODUCTION

Despite antiretroviral therapy (ART) scale-up among people living with HIV (PLHIV), those with advanced HIV disease (AHD) (defined in adults as CD4 count <200 cells/mm3 or clinical stage 3 or 4), remain at high risk of death from opportunistic infections. The shift from routine baseline CD4 testing towards viral load testing in conjunction with "Test and Treat" has limited AHD identification.

METHODS

We used official estimates and existing epidemiological data to project deaths from tuberculosis (TB) and cryptococcal meningitis (CM) among PLHIV-initiating ART with CD4 <200 cells/mm3 , in the absence of select World Health Organization recommended diagnostic or therapeutic protocols for patients with AHD. We modelled the reduction in deaths, based on the performance of screening/diagnostic testing and the coverage and efficacy of treatment/preventive therapies for TB and CM. We compared projected TB and CM deaths in the first year of ART from 2019 to 2024, with and without CD4 testing. The analysis was performed for nine countries: South Africa, Kenya, Lesotho, Mozambique, Nigeria, Uganda, Zambia, Zimbabwe and the Democratic Republic of Congo.

RESULTS

The effect of CD4 testing comes through increased identification of AHD and consequent eligibility for protocols for AHD prevention, diagnosis and management; algorithms for CD4 testing avert between 31% and 38% of deaths from TB and CM in the first year of ART. The number of CD4 tests required per death averted varies widely by country from approximately 101 for South Africa to 917 for Kenya.

CONCLUSIONS

This analysis supports retaining baseline CD4 testing to avert deaths from TB and CM, the two most deadly opportunistic infections among patients with AHD. However, national programmes will need to weigh the cost of increasing CD4 access against other HIV-related priorities and allocate resources accordingly.

Value analysis of next-generation sequencing combined with Xpert in early precise diagnosis of pulmonary tuberculosis

The current study aims to investigate the value of combination of NGS with Xpert MTB/RIF in the diagnosis of early pulmonary tuberculosis (PTB). A total of 85 patients with suspected PTB were analyzed retrospectively. The positive detection rates of PTB by Xpert MTB/RIF, TBseq Ultra, TB-DNA, and TB-RNA were significantly higher than those by acid-fast staining. Xpert MTB/RIF, TBseq Ultra, TB-DNA, and TB-RNA possessed higher sensitivity and accuracy than acid-fast stained smears. Kappa agreement analysis showed good agreement between Xpert MTB/RIF and TBseq Ultra. Combined diagnosis improves the detection sensitivity compared with a single diagnostic method. ROC curve analysis showed that Xpert MTB/RIF combined with TBseq Ultra showed the highest area under the curve (0.886). In conclusion, the combined diagnosis of TBseq Ultra and Xpert MTB/RIF harbors the characteristics of short cycle, high specificity and accuracy, which demonstrated a promising application value in the early diagnosis of PTB.

Health economic analyses of latent tuberculosis infection screening and preventive treatment among people living with HIV in lower tuberculosis incidence settings: a systematic review

Introduction: In lower tuberculosis (TB) incidence countries (<100 cases/100,000/year), screening and preventive treatment (PT) for latent TB infection (LTBI) among people living with HIV (PLWH) is often recommended, yet guidelines advising which groups to prioritise for screening can be contradictory and implementation patchy. Evidence of LTBI screening cost-effectiveness may improve uptake and health outcomes at reasonable cost. Methods: Our systematic review assessed cost-effectiveness estimates of LTBI screening/PT strategies among PLWH in lower TB incidence countries to identify model-driving inputs and methodological differences. Databases were searched 1980-2020. Studies including health economic evaluation of LTBI screening of PLWH in lower TB incidence countries (<100 cases/100,000/year) were included. Results: Of 2,644 articles screened, nine studies were included. Cost-effectiveness estimates of LTBI screening/PT for PLWH varied widely, with universal screening/PT found highly cost-effective by some studies, while only targeting to high-risk groups (such as those from mid/high TB incidence countries) deemed cost-effective by others. Cost-effectiveness of strategies screening all PLWH from studies published in the past five years varied from US$2828 to US$144,929/quality-adjusted life-year gained (2018 prices). Study quality varied, with inconsistent reporting of methods and results limiting comparability of studies. Cost-effectiveness varied markedly by screening guideline, with British HIV Association guidelines more cost-effective than NICE guidelines in the UK. Discussion: Cost-effectiveness studies of LTBI screening/PT for PLWH in lower TB incidence settings are scarce, with large variations in methods and assumptions used, target populations and screening/PT strategies evaluated. The limited evidence suggests LTBI screening/PT may be cost-effective for some PLWH groups but further research is required, particularly on strategies targeting screening/PT to PLWH at higher risk. Standardisation of model descriptions and results reporting could facilitate reliable comparisons between studies, particularly to identify those factors driving the wide disparity between cost-effectiveness estimates. Registration: PROSPERO CRD42020166338 (18/03/2020).

Programmatic Cost-Effectiveness of a Second-Time Visit to Detect New Tuberculosis and Diabetes Mellitus in TB Contact Tracing in Myanmar

BACKGROUND

Integration of diabetes mellitus screening in home visits for contact tracing for tuberculosis could identify hidden patients with either tuberculosis or diabetes mellitus. However, poor compliance to the first home screening has been reported. A second time visit not only increases screening compliance but also the cost. This study aimed to determine if an additional second time visit was cost effective based on the health system perspective of the tuberculosis contact tracing program in Myanmar.

METHODS

This cross-sectional study was based on usual contact tracing activity in the Yangon Region, Myanmar, from April to December 2018 with integration of diabetes mellitus screening and an additional home visit to take blood glucose tests along with repeated health education and counseling to stress the need for a chest X-ray. New tuberculosis and diabetes mellitus cases detected were the main outcome variables. Programmatic operational costs were calculated based on a standardized framework for cost evaluation on tuberculosis screening. The effectiveness of an additional home visit was estimated using disability-adjusted life years averted. The willingness to pay threshold was taken as 1250.00 US dollars gross domestic product per capita of the country.

RESULTS

Single and additional home visits could lead to 42.5% and 65.0% full compliance and 27.2 and 9.3 additional years of disability-adjusted life years averted, respectively. The respective base costs and additional costs were 3280.95 US dollars and 1989.02 US dollars. The programmatic costs for an extra unit of disability-adjusted life years averted was 213.87 US dollars, which was lower than the willingness to pay threshold.

CONCLUSIONS

From the programmatic perspective, conducting the second time visit for tuberculosis contact tracing integrated with diabetes mellitus screening was found to be cost effective.

Assessment of tuberculosis case notification rate: spatial mapping of hotspot, coverage and diagnostics in Katsina State, north-western Nigeria

Tuberculosis (TB) is prevalent in Nigeria, and Katsina, along with other 12 states in the country, accounts for a high proportion of unnotified TB cases: constituting the high priority-intervention States in the country. Interventions focused on TB detection and coverage in the state could benefit from a better understanding of hotspot Local Government Areas (LGAs) that trigger and sustain the disease. Therefore, this study investigated the spatial distribution of TB Case Notification Rates (CNRs), diagnostics and coverage across the LGAs. Using 2017 to 2019 TB case finding data, the geocoordinates of diagnostic facilities and shapefiles, a retrospective ecological study was conducted. The data were analysed with QGIS and GeoDa. Moran's I and LISA were used to locate and quantify hotspots. The coverage of microscopy and GeneXpert facilities was assessed on QGIS using a 5 km and 20 km radius, respectively. The CNR in the state, and 29 of the 34 LGAs, increased steadily from 2017 to 2019. Hotspots of high CNRs were also identified in 2017 (Moran's I=0.106, p-value=0.090) and 2018 (Moran's I=-0.020, p-value=0.370). While CNRs increased along with presumptive TB rates across most LGAs over the years, the positivity yield and bacteriological and Xpert diagnostic rates decreased. Bacteriological and GeneXpert coverage were 78% and 49% respectively. Additionally, only 51% of the state's population lived within 20km of a GeneXpert facility. These results suggest that TB program interventions had some positive impact on the CNR, however, diagnostic facilities need to be equitably distributed and more innovative approaches need to be explored to find the missing cases.

Effect of sputum quality and role of Xpert® MTB/ RIF assay for detection of smear-negative pulmonary tuberculosis in same-day diagnosis strategy in Addis Ababa, Ethiopia

Background

There is limited information on the performance of the Xpert® MTB/RIF test for diagnosis of smear-negative pulmonary tuberculosis (SNPT) and rifampicin resistance (RR) in the same-day diagnosis approach. The effects of sputum quality and other factors affecting the Xpert performance are also under-investigated.

Objective

This study aimed to determine the performance of the Xpert® MTB/RIF test for detection of SNPT and RR in the same-day diagnosis strategy and the effect of sputum quality and other factors on its performance.

Methods

A cross-sectional study was conducted from August 2017 to January 2018 across 16 health facilities in Addis Ababa, Ethiopia. Two spot sputum samples were collected from 418 presumptive SNPT patients, tested with Xpert® MTB/RIF, then compared to tuberculosis culture. Additionally, culture isolates were tested for RR by BACTEC MGIT™ 960 drug susceptibility testing (DST) and MTBDRplus version 2.

Results

The Xpert® MTB/RIF test detected 24 (5.7%) SNPT cases, with a sensitivity of 92.3% (75.9% - 97.9%) and specificity of 99.2% (97.8% - 99.7%) compared with tuberculosis culture. Xpert® MTB/RIF also detected three (11.58%) RR strains with 100.0% concordance with BACTEC MGIT™ 960 DST and MTBDRplus results. Three blood-stained SNPT samples were positive by Xpert (30.0%), which was 6.9 times higher compared to salivary sputum (odds ratio: 6.9, 95% confidence interval: 1.36-34.96, p = 0.020).

Conclusion

The performance of the Xpert® MTB/RIF to detect SNPT and RR in same-day diagnosis is high. However, SNPT positivity varies among sputum qualities, and good sample collection is necessary for better test performance.

Accuracy of GenoQuick MTB test in detection of Mycobacterium tuberculosis in sputum from TB presumptive patients in Uganda

Objective:

The objective of the study was to determine the diagnostic performance of the GenoQuick MTB test on heated sputum against the conventional Lowenstein–Jensen Mycobacterium tuberculosis culture as the reference method for tuberculosis diagnosis.

Introduction:

Fast, reliable, and easy-to-use tests for tuberculosis diagnosis are essential to achieving the Sustainable Development Goal of diagnosing and treating 90% of tuberculosis patients by 2030. We evaluated the diagnostic performance of the GenoQuick MTB, a polymerase chain reaction–lateral flow test, in Uganda, a resource-constrained, high tuberculosis- and HIV-burden setting.

Methods:

Fresh sputum samples from presumptive tuberculosis patients at Mulago Hospital were tested for M. tuberculosis using smear microscopy, GenoQuick MTB test, and Lowenstein–Jensen culture. For the GenoQuick MTB test, mycobacterial DNA was extracted by heating sputum at 95°C for 30 min while DNA amplification and detection were done following the manufacturer’s protocol (Hain Lifescience, Nehren, Germany). Sensitivity, specificity, and kappa agreements were calculated against Lowenstein–Jensen M. tuberculosis culture as a reference test using STATA V12.

Results:

Of the 86 tested samples, 30.2% had culture-confirmed pulmonary tuberculosis. Overall, sensitivity was higher for GenoQuick MTB (81%, 95% confidence interval: 60%−93%) than for smear microscopy (69%, 95% confidence interval: 48%−86%). Among people living with HIV, sensitivity was identical for GenoQuick MTB and smear tests (75%, 95% confidence interval: 42%−95%). Contrastingly, smear had a higher overall specificity (98%, 95% confidence interval: 91%−100%) than for GenoQuick MTB (92%, 95% confidence interval: 81%−97%). A similar trend of specificity was observed among the people living with HIV for smear microscopy (100%, 95% CI: 87%−100%) and for GenoQuick MTB (96%, 95% confidence interval: 81%−100%).

Conclusion:

The GenoQuick MTB test could be a potential tuberculosis diagnostic test given its higher sensitivity. Evaluation of this test in larger studies is recommended.

Cost-effectiveness of GeneXpert Omni compared with GeneXpert MTB/Rif for point-of-care diagnosis of tuberculosis in a low-resource, high-burden setting in Eastern Uganda: a cost-effectiveness analysis based on decision analytical modelling

OBJECTIVE

To determine the cost-effectiveness of Xpert Omni compared with Xpert MTB/Rif for point-of-care diagnosis of tuberculosis among presumptive cases in a low-resource, high burden facility.

DESIGN

Cost-effectiveness analysis from the provider's perspective.

SETTING

A low-resource, high tuberculosis burden district in Eastern Uganda.

PARTICIPANTS

A provider's perspective was used, and thus, data were collected from experts in the field of tuberculosis diagnosis purposively selected at the local, subnational and national levels.

METHODS

A decision analysis model was contracted from TreeAge comparing Xpert MTB/Rif and Xpert Omni. Cost estimation was done using the ingredients' approach. One-way deterministic sensitivity analyses were performed to identify the most influential model parameters.

OUTCOME MEASURE

The outcome measure was incremental cost per additional test diagnosed expressed as the incremental cost-effectiveness ratio.

RESULTS

The total cost per test for Xpert MTB/Rif was US$14.933. Cartridge and reagent kits contributed to 67% of Xpert MTB/Rif costs. Sample transport costs increased the cost per test of Xpert MTB/Rif by $1.28. The total cost per test for Xpert Omni was $16.153. Cartridge and reagent kits contributed to over 71.2% of Xpert Omni's cost per test. The incremental cost-effectiveness ratio for using Xpert Omni as a replacement for Xpert MTB/Rif was US$30.73 per additional case detected. There was no dominance noted in the cost-effectiveness analysis, meaning no strategy was dominant over the other.

CONCLUSION

The use of Xpert Omni at the point-of-care health facility was more effective but with an increased cost compared with Xpert MTB/Rif at the centralised referral testing facility.

Cost and affordability of scaling up tuberculosis diagnosis using Xpert MTB/RIF testing in West Java, Indonesia

In Indonesia, a significant number of tuberculosis (TB) cases may be missed, due to the low sensitivity and specificity of the currently used diagnostic algorithm. In this regard, the rapid molecular test using Xpert MTB/RIF, which has recently been introduced in Indonesia, can improve case detection. Thus, this study determined the cost and affordability of incorporating Xpert MTB/RIF testing for TB diagnosis. For this purpose, we estimated the costs (from the health system and societal perspectives) of reaching the TB detection target in Depok municipality, and applied the findings to the West Java province of Indonesia. The resources available for the health and TB program were also analyzed to support the decision to scale up the TB diagnosis using Xpert MTB/RIF testing. According to the results, the unit cost for TB diagnosis per person was USD 27.22 and USD 70.16 from the health system and societal perspectives, respectively. To reach the target of 109,843 TB cases for the 2020–2024 time period, Depok municipality would need USD 2,989,927 and USD 2,549,455 from the health system viewpoint, assuming the machine’s lifespan of five and 10 years, respectively. Extrapolating these results to the West Java province, USD 56,353,833 would be necessary to test 2,076,413 cases from 2019 to 2024. However, in order to accelerate the case detection target up to 2024, West Java requires additional funds. The implication of the findings is that the central government must consider local capacity to accelerate TB case detection and ensure that the installation of Xpert MTB/RIF machines is included in the overall costs.

Economic Analyses of Respiratory Tract Infection Diagnostics: A Systematic Review

BACKGROUND

Diagnostic testing for respiratory tract infections is a tool to manage the current COVID-19 pandemic, as well as the rising incidence of antimicrobial resistance. At the same time, new European regulations for market entry of in vitro diagnostics, in the form of the in vitro diagnostic regulation, may lead to more clinical evidence supporting health-economic analyses.

OBJECTIVE

The objective of this systematic review was to review the methods used in economic evaluations of applied diagnostic techniques, for all patients seeking care for infectious diseases of the respiratory tract (such as pneumonia, pulmonary tuberculosis, influenza, sinusitis, pharyngitis, sore throats and general respiratory tract infections).

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, articles from three large databases of scientific literature were included (Scopus, Web of Science and PubMed) for the period January 2000 to May 2020.

RESULTS

A total of 70 economic analyses are included, most of which use decision tree modelling for diagnostic testing for respiratory tract infections in the community-care setting. Many studies do not incorporate a generally comparable clinical outcome in their cost-effectiveness analysis: fewer than half the studies (33/70) used generalisable outcomes such as quality-adjusted life-years. Other papers consider outcomes related to the accuracy of the test or outcomes related to the prescribed treatment. The time horizons of the studies generally are limited.

CONCLUSIONS

The methods to economically assess diagnostic tests for respiratory tract infections vary and would benefit from clear recommendations from policy makers on the assessed time horizon and outcomes used.

Active Case Finding for Tuberculosis in India: A Syntheses of Activities and Outcomes Reported by the National Tuberculosis Elimination Programme

India launched a national community-based active TB case finding (ACF) campaign in 2017 as part of the strategic plan of the National Tuberculosis Elimination Programme (NTEP). This review evaluated the outcomes for the components of the ACF campaign against the NTEP’s minimum indicators and elicited the challenges faced in implementation. We supplemented data from completed pretested data proformas returned by ACF programme managers from nine states and two union territories (for 2017–2019) and five implementing partner agencies (2013–2020), with summary national data on the state-wise ACF outcomes for 2018–2020 published in annual reports by the NTEP. The data revealed variations in the strategies used to map and screen vulnerable populations and the diagnostic algorithms used across the states and union territories. National data were unavailable to assess whether the NTEP indicators for the minimum proportions identified with presumptive TB among those screened (5%), those with presumptive TB undergoing diagnostic tests (>95%), the minimum sputum smear positivity rate (2% to 3%), those with negative sputum smears tested with chest X-rays or CBNAAT (>95%) and those diagnosed through ACF initiated on anti-TB treatment (>95%) were fulfilled. Only 30% (10/33) of the states in 2018, 23% (7/31) in 2019 and 21% (7/34) in 2020 met the NTEP expectation that 5% of those tested through ACF would be diagnosed with TB (all forms). The number needed to screen to diagnose one person with TB (NNS) was not included among the NTEP’s programme indicators. This rough indicator of the efficiency of ACF varied considerably across the states and union territories. The median NNS in 2018 was 2080 (interquartile range or IQR 517–4068). In 2019, the NNS was 2468 (IQR 1050–7924), and in 2020, the NNS was 906 (IQR 108–6550). The data consistently revealed that the states that tested a greater proportion of those screened during ACF and used chest X-rays or CBNAAT (or both) to diagnose TB had a higher diagnostic yield with a lower NNS. Many implementation challenges, related to health systems, healthcare provision and difficulties experienced by patients, were elicited. We suggest a series of strategic interventions addressing the implementation challenges and the six gaps identified in ACF outcomes and the expected indicators that could potentially improve the efficacy and effectiveness of community-based ACF in India.

Costs and cost-effectiveness of Gene Xpert compared to smear microscopy for the diagnosis of pulmonary tuberculosis using real-world data from Arsi zone, Ethiopia

Background

Early diagnosis and treatment are one of the key strategies of tuberculosis control globally, and there are strong efforts in detecting and treating tuberculosis cases in Ethiopia. Smear microscopy examination has been a routine diagnostic test for pulmonary tuberculosis diagnosis in resource-constrained settings for decades. Recently, many countries, including Ethiopia, are scaling up the use of Gene Xpert without the evaluation of the cost and cost-effectiveness implications of this strategy. Therefore, this study evaluated the cost and cost-effectiveness of Gene Xpert (MTB/RIF) and smear microscopy tests to diagnosis tuberculosis patients in Ethiopia.

Methods

We compared the costs and cost-effectiveness of tuberculosis diagnosis using smear microscopy and Gene Xpert among 1332 patients per intervention in the Arsi zone. We applied combinations of top-down and bottom-up costing approaches. The costs were estimated from the health providers’ perspective within one year (2017–2018). We employed “cases detected” as an effectiveness measure, and the incremental cost-effectiveness ratio was calculated by dividing the changes in cost and change in effectiveness. All costs and incremental cost-effectiveness ratio were reported in 2018 US$.

Results

The unit cost per test for Gene Xpert was $12.9 whereas it is $3.1 for AFB smear microscopy testing. The cost per TB case detected was $77.9 for Gene Xpert while it was $55.8 for the smear microscopy method. The cartridge kit cost accounted for 42% of the overall Gene Xpert’s costs and the cost of the reagents and consumables accounted for 41.3% ($1.3) of the unit cost for the smear microscopy method. The ICER for the Gene Xpert strategy was $20.0 per tuberculosis case detected.

Conclusion

Using Gene Xpert as a routine test instead of standard care (smear microscopy) can be potentially cost-effective. In the cost scenario analysis, the price of the cartridge, the number of tests performed per day, and the life span of the capital equipment were the drivers of the unit cost of the Gene Xpert method. Therefore, Gene Xpert can be a part of the routine TB diagnostic testing strategy in Ethiopia.

Predicting the impact of control strategies on the tuberculosis burden in South and North Korea using a mathematical model

BACKGROUND

Among high-income countries, South Korea has a considerable tuberculosis (TB) burden; North Korea has one of the highest TB burdens in the world. Predicting the impact of control strategies on the TB burden can help to efficiently implement TB control programmes.

METHODS

We designed a deterministic compartmental model of TB in Korea. After calibration with notification of incidence data from South Korea, the TB burden for 2040 was predicted according to four different intervention strategies: latent TB infection (LTBI) treatment, rapid diagnosis, active case-finding and improvement of the treatment success rate. North Korea's burden in 2040 was similarly estimated by adjusting the model parameters.

RESULTS

In South Korea, the number of patients with drug-susceptible TB (DS-TB) and multidrug-resistant TB (MDR-TB) were predicted to be 27 581 and 625, respectively, in 2025. Active case-finding would lower DS-TB by 6.2% and MDR-TB by 26.7%, respectively, in 2040. The improvement in the success rate of DS-TB treatment would reduce the MDR-TB burden by 34.5%. In North Korea, the number of patients with DS-TB and MDR-TB are, respectively, predicted to be 77 629 and 5409 in 2025. Active case-finding would reduce DS-TB by 22.2% and MDR-TB by 69.7%. LTBI treatment would reduce DS-TB by 20.6% and MDR-TB by 38.6%.

CONCLUSION

The impact of control strategies on the TB burden in South and North Korea was investigated using a mathematical model. The combined intervention strategies would reduce the burden and active case-finding is expected to result in considerable reduction in both South and North Korea.

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.

Impact of the gate-keeping policies of China's primary healthcare model on the future burden of tuberculosis in China: a protocol for a mathematical modelling study

INTRODUCTION

In the past three decades, China has made great strides in the prevention and treatment of tuberculosis (TB). However, the TB burden remains high. In 2019, China accounted for 8.4% of global incident cases of TB, the third highest in the world, with a higher prevalence in rural areas. The Healthy China 2030 highlights the gate-keeping role of primary healthcare (PHC). However, the impact of PHC reforms on the future TB burden is unclear. We propose to use mathematical models to project and evaluate the impacts of different gate-keeping policies.

METHODS AND ANALYSIS

We will develop a deterministic, population-level, compartmental model to capture the dynamics of TB transmission within adult rural population. The model will incorporate seven main TB statuses, and each compartment will be subdivided by service providers. The parameters involving preference for healthcare seeking will be collected using discrete choice experiment (DCE) method. We will solve the deterministic model numerically over a 20-year (2021-2040) timeframe and predict the TB prevalence, incidence and cumulative new infections under the status quo or various policy scenarios. We will also conduct an analysis following standard protocols to calculate the average cost-effectiveness for each policy scenario relative to the status quo. A numerical calibration analysis against the available published TB prevalence data will be performed using a Bayesian approach.

ETHICS AND DISSEMINATION

Most of the data or parameters in the model will be obtained based on secondary data (eg, published literature and an open-access data set). The DCE survey has been reviewed and approved by the Ethics Committee of the School of Public Health, Sun Yat-sen University. The approval number is SYSU [2019]140. Results of the study will be disseminated through peer-reviewed journals, media and conference presentations.

The effect of empirical and laboratory-confirmed tuberculosis on treatment outcomes

The World Health Organization (WHO) criteria for diagnosing and treating Tuberculosis (TB) includes clinical signs, therefore not requiring bacteriological laboratory confirmation. In resource-limited settings, including Kenya, this empirical TB treatment is routine practice however limited data exist on patient clinical outcomes when comparing the method of diagnosis. We evaluated TB treatment outcomes comparing clinically diagnosed and bacteriologically confirmed TB, 6 months after starting treatment of TB in a rural county in Kenya. Our analysis compared patients with a clinical versus a bacteriologically confirmed TB diagnosis. In this retrospective analysis, we included all adults (≥ 18 years) starting treatment of TB and followed up for 6 months, within the County TB surveillance database from 2012 to 2018. Patients included from both public and private facilities. The TB treatment outcomes assessed included treatment success, treatment failure, death, defaulted and transferred out. We used survival regression models to assess effect of type of diagnosis on TB treatment outcome defining time at risk from date of starting treatment to experiencing one of the treatment outcomes or completing 6-months of treatment. A total of 12,856 patients; median age 37 [IQR 28 − 50] years were included. 7639 (59%) were male while 11,339 (88%) were pulmonary TB cases. Overall, 11,633 (90%) were given first-line TB treatment and 3791 (29%) were HIV infected. 6472 (50%) of the patients were clinically diagnosed of whom 4521/6472 (70%) had a negative sputum/GeneXpert test. During the study 5565 person-years (PYs) observed, treatment success was 82% and 83% amongst clinically and bacteriologically diagnosed patients (P = 0.05). There were no significant differences in defaulting (P = 0.70) or transfer out (P = 0.19) between clinically and bacteriologically diagnosed patients. Mortality was significantly higher among clinically diagnosed patients: 639 (9.9%) deaths compared to 285 (4.5%) amongst the bacteriologically diagnosed patients; aHR 5.16 (95%CI 2.17 − 12.3) P < 0.001. Our study suggests survival during empirical TB treatment is significantly lower compared to patients with laboratory evidence, irrespective of HIV status and age. To improve TB treatment outcomes amongst clinically diagnosed patients, we recommend systematic screening for comorbidities, prompt diagnosis and management of other infections.

Effectiveness and trend forecasting of tuberculosis diagnosis after the introduction of GeneXpert in a city in south-eastern Brazil

BACKGROUND

To evaluate the effectiveness of a rapid molecular test for the detection of tuberculosis (TB) and to predict the rates of disease in a municipality of Brazil where TB is endemic.

METHODS

An ecological study was carried out in Ribeirão Preto-SP on a population of TB cases notified between 2006 and 2017. Monthly TB incidence rates and the average monthly percentage change (AMPC) were calculated. In order to identify changes in the series, the breakpoint technique was performed; the rates were modelled and predictions of the incidence of TB until 2025 were made.

RESULTS

AMPC showed a fall of 0.69% per month in TB and human immunodeficiency virus (TB-HIV) co-infection, a fall of 0.01% per month in general and lung TB and a fall of 0.33% per month in extrapulmonary TB. With the breakpoint technique, general and pulmonary TB changed in structure in late 2007, and extrapulmonary TB and TB-HIV co-infection changed in structure after 2014, which is considered the cut-off point. The IMA(3) models were adjusted for general and pulmonary TB and TB-HIV co-infection, and the AR(5) models for extrapulmonary TB, and predictions were performed.

CONCLUSIONS

The rapid molecular test for TB is the method currently recommended by the WHO for the diagnosis of the disease and its main advantage is to provide faster, more accurate results and to already check for drug resistance. It is necessary that professionals encourage the use of this technology in order to optimize the diagnosis so that the treatment begins as quickly as possible and in an effective way. Only by uniting professionals from all areas with health policies aimed at early case identification and rapid treatment initiation it is possible to break the chain of TB transmission so that its rates decrease and the goals proposed by the WHO are achieved.

Strengthening health systems to improve the value of tuberculosis diagnostics in South Africa: A cost and cost-effectiveness analysis

BACKGROUND

In South Africa, replacing smear microscopy with Xpert-MTB/RIF (Xpert) for tuberculosis diagnosis did not reduce mortality and was cost-neutral. The unchanged mortality has been attributed to suboptimal Xpert implementation. We developed a mathematical model to explore how complementary investments may improve cost-effectiveness of the tuberculosis diagnostic algorithm.

METHODS

Complementary investments in the tuberculosis diagnostic pathway were compared to the status quo. Investment scenarios following an initial Xpert test included actions to reduce pre-treatment loss-to-follow-up; supporting same-day clinical diagnosis of tuberculosis after a negative result; and improving access to further tuberculosis diagnostic tests following a negative result. We estimated costs, deaths and disability-adjusted-life-years (DALYs) averted from provider and societal perspectives. Sensitivity analyses explored the mediating influence of behavioural, disease- and organisational characteristics on investment effectiveness.

FINDINGS

Among a cohort of symptomatic patients tested for tuberculosis, with an estimated active tuberculosis prevalence of 13%, reducing pre-treatment loss-to-follow-up from ~20% to ~0% led to a 4% (uncertainty interval [UI] 3; 4%) reduction in mortality compared to the Xpert scenario. Improving access to further tuberculosis diagnostic tests from ~4% to 90% among those with an initial negative Xpert result reduced overall mortality by 28% (UI 27; 28) at $39.70/ DALY averted. Effectiveness of investment scenarios to improve access to further diagnostic tests was dependent on a high return rate for follow-up visits.

INTERPRETATION

Investing in direct and indirect costs to support the TB diagnostic pathway is potentially highly cost-effective.

Cost-effectiveness of one month of daily isoniazid and rifapentine versus three months of weekly isoniazid and rifapentine for prevention of tuberculosis among people receiving antiretroviral therapy in Uganda

Introduction

Preventive therapy is essential for reducing tuberculosis (TB) burden among people living with HIV (PLWH) in high‐burden settings. Short‐course preventive therapy regimens, such as three‐month weekly rifapentine and isoniazid (3HP) and one‐month daily rifapentine and isoniazid (1HP), may help facilitate uptake of preventive therapy for latently infected patients, but the comparative cost‐effectiveness of these regimens under different conditions is uncertain.

Methods

We used a Markov state‐transition model to estimate the incremental costs and effectiveness of 1HP versus 3HP in a simulated cohort of patients attending an HIV clinic in Uganda, as an example of a low‐income, high‐burden setting in which TB preventive therapy might be prescribed to PLWH. Our primary outcome was the incremental cost‐effectiveness ratio, expressed as 2019 US dollars per disability‐adjusted life year (DALY) averted. We estimated cost‐effectiveness under different conditions of treatment completion and efficacy of 1HP versus 3HP, latent TB prevalence and rifapentine price.

Results

Assuming equivalent clinical outcomes using 1HP and 3HP and a rifapentine price of $0.21 per 150 mg, 1HP would cost an additional $4.66 per patient treated. Assuming equivalent efficacy but 20% higher completion with 1HP versus 3HP, 1HP would cost $1,221 per DALY averted relative to 3HP. This could be reduced to $18 per DALY averted if 1HP had 5% greater efficacy than 3HP and the price of rifapentine were 50% lower. At a rifapentine price of $0.06 per 150 mg, 1HP would become cost‐neutral relative to 3HP.

Conclusions

1HP has the potential to be cost‐effective under many realistic circumstances. Cost‐effectiveness depends on rifapentine price, relative completion and efficacy, prevalence of latent TB and local willingness‐to‐pay.

Health economic analyses of latent tuberculosis infection screening and preventive treatment among people living with HIV in lower tuberculosis incidence settings: a systematic review

Introduction: In lower tuberculosis (TB) incidence countries (<100 cases/100,000/year), screening and preventive treatment (PT) for latent TB infection (LTBI) among people living with HIV (PLWH) is often recommended, yet guidelines advising which groups to prioritise for screening can be contradictory and implementation patchy. Evidence of LTBI screening cost-effectiveness may improve uptake and health outcomes at reasonable cost. Methods: Our systematic review assessed cost-effectiveness estimates of LTBI screening/PT strategies among PLWH in lower TB incidence countries to identify model-driving inputs and methodological differences. Databases were searched 1980-2020. Studies including health economic evaluation of LTBI screening of PLWH in lower TB incidence countries (<100 cases/100,000/year) were included. Study quality was assessed using the CHEERS checklist. Results: Of 2,644 articles screened, nine studies were included. Cost-effectiveness estimates of LTBI screening/PT for PLWH varied widely, with universal screening/PT found highly cost-effective by some studies, while only targeting to high-risk groups (such as those from mid/high TB incidence countries) deemed cost-effective by others. Cost-effectiveness of strategies screening all PLWH from studies published in the past five years varied from US$2828 to US$144,929/quality-adjusted life-year gained (2018 prices). Study quality varied, with inconsistent reporting of methods and results limiting comparability of studies. Cost-effectiveness varied markedly by screening guideline, with British HIV Association guidelines more cost-effective than NICE guidelines in the UK. Discussion: Cost-effectiveness studies of LTBI screening/PT for PLWH in lower TB incidence settings are scarce, with large variations in methods and assumptions used, target populations and screening/PT strategies evaluated. The limited evidence suggests LTBI screening/PT may be cost-effective for some PLWH groups but further research is required, particularly on strategies targeting screening/PT to PLWH at higher risk. Standardisation of model descriptions and results reporting could facilitate reliable comparisons between studies, particularly to identify those factors driving the wide disparity between cost-effectiveness estimates. Registration: PROSPERO CRD42020166338 (18/03/2020).

Integrating Xpert MTB/RIF for TB diagnosis in the private sector: evidence from large-scale pilots in Patna and Mumbai, India

Background

Xpert MTB/RIF (Xpert) has been recommended by WHO as the initial diagnostic test for TB and rifampicin-resistance detection. Existing evidence regarding its uptake is limited to public health systems and corresponding resource and infrastructure challenges. It cannot be readily extended to private providers, who treat more than half of India’s TB cases and demonstrate complex diagnostic behavior.

Methods

We used routine program data collected from November 2014 to April 2017 from large-scale private sector engagement pilots in Mumbai and Patna. It included diagnostic vouchers issued to approximately 150,000 patients by about 1400 providers, aggregated to 18,890 provider-month observations. We constructed three metrics to capture provider behavior with regards to adoption of Xpert and studied their longitudinal variation: (i) Uptake (ordering of test), (ii) Utilization for TB diagnosis, and (iii) Non-adherence to negative results. We estimated multivariate linear regression models to assess heterogeneity in provider behavior based on providers’ prior experience and Xpert testing volumes.

Results

Uptake of Xpert increased considerably in both Mumbai (from 36 to 60.4%) and Patna (from 12.2 to 45.1%). However, utilization of Xpert for TB diagnosis and non-adherence to negative Xpert results did not show systematic trends over time. In regression models, cumulative number of Xpert tests ordered was significantly associated with Xpert uptake in Patna and utilization for diagnosis in Mumbai (p-value< 0.01). Uptake of Xpert and its utilization for diagnosis was predicted to be higher in high-volume providers compared to low-volume providers and this gap was predicted to widen over time.

Conclusions

Private sector engagement led to substantial increase in uptake of Xpert, especially among high-volume providers, but did not show strong evidence of Xpert results being integrated with TB diagnosis. Increasing availability and affordability of a technically superior diagnostic tool may not be sufficient to fundamentally change diagnosis and treatment of TB in the private sector. Behavioral interventions, specifically aimed at, integrating Xpert results into clinical decision making of private providers may be required to impact patient-level outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-05817-1.

Chest X-ray interpretation does not complement Xpert MTB/RIF in diagnosis of smear-negative pulmonary tuberculosis among TB-HIV co-infected adults in a resource-limited setting

Background

Chest X-ray (CXR) interpretation remains a central component of the current World Health Organization recommendations as an adjuvant test in diagnosis of smear-negative tuberculosis (TB). With its low specificity, high maintenance and operational costs, utility of CXR in diagnosis of smear-negative TB in high HIV/TB burden settings in the Xpert MTB/RIF era remains unpredictable. We evaluated accuracy and additive value of CXR to Xpert MTB/RIF in the diagnosis of TB among HIV-positive smear-negative presumptive TB patients.

Methods

HIV co-infected presumptive TB patients were recruited from the Infectious Diseases Institute outpatient clinic and in-patient medical wards of Mulago Hospital, Uganda. CXR films were reviewed by two independent radiologists using a standardized evaluation form. CXR interpretation with regard to TB was either positive (consistent with TB) or negative (normal or unlikely TB). Sensitivity, specificity and predictive values of CXR and CXR combined with Xpert MTB/RIF for diagnosis of smear-negative TB in HIV-positive patients were calculated using sputum and/or blood mycobacterial culture as reference standard.

Results

Three hundred sixty-six HIV co-infected smear-negative participants (female, 63.4%; hospitalized, 68.3%) had technically interpretable CXR. Median (IQR) age was 32 (28–39) years and CD4 count 112 (23–308) cells/mm³. Overall, 22% (81/366) were positive for Mycobacterium tuberculosis (Mtb) on culture; 187/366 (51.1%) had CXR interpreted as consistent with TB, of which 55 (29.4%) had culture-confirmed TB. Sensitivity and specificity of CXR interpretation in diagnosis of culture-positive TB were 67.9% (95%CI 56.6–77.8) and 53.7% (95%CI 47.7–59.6) respectively, while Xpert MTB/RIF sensitivity and specificity were 65.4% (95%CI 54.0–75.7) and 95.8% (95%CI 92.8–97.8) respectively. Addition of CXR to Xpert MTB/RIF had overall sensitivity and specificity of 87.7% (95%CI 78.5–93.9) and 51.6% (95%CI 45.6–57.5) respectively; 86.2% (95%CI 75.3–93.5) and 48.1% (95%CI 40.7–55.6) among inpatients and 93.8% (95%CI 69.8–99.8) and 58.0% (95%CI 47.7–67.8) among outpatients respectively.

Conclusion

In this high prevalence TB/HIV setting, CXR interpretation added sensitivity to Xpert MTB/RIF test at the expense of specificity in the diagnosis of culture-positive TB in HIV-positive individuals presenting with TB symptoms and negative smear. CXR interpretation may not add diagnostic value in settings where Xpert MTB/RIF is available as a TB diagnostic tool.

Sensitivity and specificity of the mean corpuscular volume and CD4/CD8 ratio in discriminating between rifampicin resistant and rifampicin sensitive tuberculosis

Background

There is need for simple, cost effective and widely available point of care tests for low level health facilities in developing countries to screen for drug resistant tuberculosis (TB) after bacteriological confirmation of TB by smear microscopy. We evaluated the sensitivity and specificity of the mean corpuscular volume (MCV) and CD4/CD8 ratio in discriminating between rifampicin resistant (RR-TB) and rifampicin sensitive (RS-TB) tuberculosis.

Methods

We performed a secondary analysis of data from a cross sectional study that enrolled adult participants with bacteriologically confirmed pulmonary TB at a national tuberculosis treatment center in Uganda. Blood samples were tested for CD4 and CD8 cell counts, HIV serology and a full hemogram. Rifampicin sensitivity and the bacillary load grade were determined by Xpert MTB/RIF®. Fifty-five participants that had RR-TB (cases) were matched with 110 participants that had RS-TB (controls) for age, sex and HIV status in a ratio of 1:2 respectively. Sensitivity (Se), specificity (Sp), area under curve (AUC) analysis and determination of optimal cut-offs were performed using receiver operating characteristic curves.

Results

Cases differed from controls with respect to residence (p = 0.031), bacillary load grade (p < 0.010) and MCV (p = 0.021). The Se, Sp and AUC of the MCV (cut-off of > 74.6 femtolitres (fl)) were 88.9%, 34% and 0.607 (p = 0.021) respectively for RR-TB. Among HIV positive participants, the respective Se, Sp and AUC of the MCV for RR-TB (cut-off of > 72.5 fl) were 97.2%, 22.2% and 0.608 (p = 0.061). The respective Se, Sp and AUC of the CD4/CD8 ratio (cut-off of > 0.40) were 67.3%, 50.0% and 0.559 (p = 0.199) on the overall and 54.1%, 71.6% and 0.628 (p = 0.024) among the HIV positive participants for RR-TB.

Conclusion

The MCV had a high sensitivity but very low specificity for RR-TB. The CD4/CD8 ratio had a low sensitivity and specificity for RR-TB among HIV positive individuals. The utility of either test is low due to low diagnostic accuracy.

Trade-offs between cost and accuracy in active case finding for tuberculosis: A dynamic modelling analysis

BACKGROUND

Active case finding (ACF) may be valuable in tuberculosis (TB) control, but questions remain about its optimum implementation in different settings. For example, smear microscopy misses up to half of TB cases, yet is cheap and detects the most infectious TB cases. What, then, is the incremental value of using more sensitive and specific, yet more costly, tests such as Xpert MTB/RIF in ACF in a high-burden setting?

METHODS AND FINDINGS

We constructed a dynamic transmission model of TB, calibrated to be consistent with an urban slum population in India. We applied this model to compare the potential cost and impact of 2 hypothetical approaches following initial symptom screening: (i) 'moderate accuracy' testing employing a microscopy-like test (i.e., lower cost but also lower accuracy) for bacteriological confirmation and (ii) 'high accuracy' testing employing an Xpert-like test (higher cost but also higher accuracy, while also detecting rifampicin resistance). Results suggest that ACF using a moderate-accuracy test could in fact cost more overall than using a high-accuracy test. Under an illustrative budget of US$20 million in a slum population of 2 million, high-accuracy testing would avert 1.14 (95% credible interval 0.75-1.99, with p = 0.28) cases relative to each case averted by moderate-accuracy testing. Test specificity is a key driver: High-accuracy testing would be significantly more impactful at the 5% significance level, as long as the high-accuracy test has specificity at least 3 percentage points greater than the moderate-accuracy test. Additional factors promoting the impact of high-accuracy testing are that (i) its ability to detect rifampicin resistance can lead to long-term cost savings in second-line treatment and (ii) its higher sensitivity contributes to the overall cases averted by ACF. Amongst the limitations of this study, our cost model has a narrow focus on the commodity costs of testing and treatment; our estimates should not be taken as indicative of the overall cost of ACF. There remains uncertainty about the true specificity of tests such as smear and Xpert-like tests in ACF, relating to the accuracy of the reference standard under such conditions.

CONCLUSIONS

Our results suggest that cheaper diagnostics do not necessarily translate to less costly ACF, as any savings from the test cost can be strongly outweighed by factors including false-positive TB treatment, reduced sensitivity, and foregone savings in second-line treatment. In resource-limited settings, it is therefore important to take all of these factors into account when designing cost-effective strategies for ACF.

Rifampicin-Resistant Mycobacterium tuberculosis Among Patients with Presumptive Tuberculosis in Addis Ababa, Ethiopia

Background

Drug-resistant tuberculosis remains a major public health threat complicating tuberculosis control programs globally. Data on rifampicin resistance (RR), which is a surrogate marker for multidrug resistance, are limited among Ethiopian tuberculosis patients. This study aimed to determine the magnitude of rifampicin-resistant Mycobacterium tuberculosis (RR-MTB) among presumptive tuberculosis patients attending St. Peter Tuberculosis Specialized Hospital, Addis Ababa, Ethiopia.

Patients and Methods

A retrospective cross-sectional study was conducted at St. Peter Tuberculosis Specialized Hospital from January 2016 to December 2018. After checking completeness of the necessary information, data of tuberculosis-presumptive cases who underwent Gene Xpert^® testing were collected from medical records using a data-extraction format prepared for this study purpose. Data were double entered and analyzed using SPSS version 20 statistical software.

Results

A total of 12,685 presumptive tuberculosis patients were included; of whom 54.5% were males and the mean age of the study participants was 40.3±18.7 years. Mycobacterium tuberculosis (MTB) was detected in 1714 participants (13.5%). Of these MTB cases, 169 cases (9.8%) were confirmed to have RR-MTB. Prevalence of MTB was relatively higher among males (15.1%, P=0.78); whereas RR-MTB was higher among females (10.3%, P=0.81). The incidence of MTB and RR-MTB was significantly associated with treatment history (P=0.042 and P=0.025), respectively. HIV infection has significantly associated with incidence of RR-MTB (P=0.032), but not with MTB (P˃0.05). Prevalence of MTB and RR-MTB had a declining trend through time, being 16.7% and 12.9%, 12.8% and 9.1%, and 12.2% and 7.9% in 2016, 2017 and 2018, respectively.

Conclusion

This study showed a decreasing trend of both MTB and RR-MTB from 2016 to 2018 in an MTB, MDR-MTB, and TB/HIV co-infection high-burden setting, Addis Ababa, Ethiopia. Occurrence of MTB and RR-MTB was associated with treatment history. Therefore, improvement in treatment adherence of identified cases would be helpful to prevent emergence or re-emergence of MTB and RR-MTB cases.

Cost-effectiveness of post-treatment follow-up examinations and secondary prevention of tuberculosis in a high-incidence setting: a model-based analysis

BACKGROUND

In settings of high tuberculosis incidence, previously treated individuals remain at high risk of recurrent tuberculosis and contribute substantially to overall disease burden. Whether tuberculosis case finding and preventive interventions among previously treated people are cost-effective has not been established. We aimed to estimate costs and health benefits of annual post-treatment follow-up examinations and secondary preventive therapy for tuberculosis in a tuberculosis-endemic setting.

METHODS

We developed a transmission-dynamic mathematical model and calibrated it to data from two high-incidence communities of approximately 40 000 people in suburban Cape Town, South Africa. We used the model to estimate overall cost and disability-adjusted life-years (DALYs) associated with annual follow-up examinations and secondary isoniazid preventive therapy (IPT), alone and in combination, among individuals completing tuberculosis treatment. We investigated scenarios under which these interventions were restricted to the first year after treatment completion, or extended indefinitely. For each intervention scenario, we projected health system costs and DALYs averted with respect to the current status quo of tuberculosis control. All estimates represent mean values derived from 1000 epidemic trajectories simulated over a 10-year period (2019-28), with 95% uncertainty intervals (UIs) calculated as the 2·5th and 97·5th percentile values.

FINDINGS

We estimated that a single follow-up examination at the end of the first year after treatment completion combined with 12 months of secondary IPT would avert 2472 DALYs (95% UI -888 to 7801) over a 10-year period and is expected to be cost-saving compared with current control efforts. Sustained annual follow-up and continuous secondary IPT beyond the first year after treatment would avert an additional 1179 DALYs (-1769 to 4377) over 10 years at an expected additional cost of US$18·2 per DALY averted. Strategies of follow-up without secondary IPT were dominated (ie, expected to result in lower health impact at higher costs) by strategies that included secondary IPT.

INTERPRETATION

In this high-incidence setting, post-treatment follow-up and secondary preventive therapy can accelerate declines in tuberculosis incidence and potentially save resources for tuberculosis control. Empirical trials to assess the feasibility of these interventions in settings most severely affected by tuberculosis are needed.

FUNDING

National Institutes of Health, Günther Labes Foundation, Oskar Helene Heim Foundation.

Managing Uncertainties Due to Limited Evidence in Economic Evaluations of Novel Anti-Tuberculosis Regimens: A Systematic Review

BACKGROUND

Limited evidence for the implementation of new health technologies in low- and middle-income countries (LMICs) may lead to uncertainties in economic evaluations and cause the evaluations to produce inaccurate information for decision making. We performed a systematic review of economic evaluations on implementing new short-course regimens (SCR) for drug-sensitive and drug-resistant tuberculosis (TB), to explore how uncertainties due to the limited evidence in the studies were dealt with and to identify useful information for decision making from these studies.

METHODS

We searched in electronic databases PubMed, EMBASE, NHSEED, and CEA registry for economic evaluations addressing the implementation of new anti-TB SCRs in LMICs published until September 2018. We included studies addressing both the cost and outcomes of implementing a new regimen for drug-sensitive and drug-resistant TB with a shorter treatment duration than the currently used regimens. The quality of the included studies was assessed using The Consensus Health Economic Criteria checklist. We extracted information from the included studies on uncertainties and how they were managed. The management of uncertainties was compared with approaches used in early health technology assessments (HTAs), including sensitivity analyses and pragmatic scenario analyses. We extracted information that could be useful for decision making such as cost-effectiveness conclusions, and barriers to implementing the intervention.

RESULTS

Four of the 322 studies found in the search met the eligibility criteria. Three studies were model-based studies that investigated the cost effectiveness of a new first-line SCR. One study was an empirical study investigating the cost effectiveness of new regimens for drug-resistant TB. The model-based studies addressed uncertainties due to limited evidence through various sensitivity analyses as in early HTAs. They performed a deterministic sensitivity analysis and found the main drivers of the cost-effectiveness outcomes, that is, the rate of treatment default and treatment delivery costs. Additionally, two of the model-based studies performed a pragmatic scenario analysis and found a potential barrier to implementing the new first-line SCR, that is, a weak health system with a low TB care utilization rate. The empirical study only performed a few scenario analyses with different regimen prices and volumes of TB care utilization. Therefore, the study could only provide information on the main cost drivers.

CONCLUSION

Using an approach similar to that used in early HTAs, where uncertainties due to the limited evidence are rigorously explored upfront, the economic evaluations could inform not only the decision to implement the intervention but also how to manage risks and implementation barriers.

Point of care Xpert MTB/RIF versus smear microscopy for tuberculosis diagnosis in southern African primary care clinics: a multicentre economic evaluation

BACKGROUND

Rapid on-site diagnosis facilitates tuberculosis control. Performing Xpert MTB/RIF (Xpert) at point of care is feasible, even when performed by minimally trained health-care workers, and when compared with point-of-care smear microscopy, reduces time to diagnosis and pretreatment loss to follow-up. However, whether Xpert is cost-effective at point of care remains unclear.

METHODS

We empirically collected cost (US$, 2014) and clinical outcome data from participants presenting to primary health-care facilities in four African countries (South Africa, Zambia, Zimbabwe, and Tanzania) during the TB-NEAT trial. Costs were determined using an bottom-up ingredients approach. Effectiveness measures from the trial included number of cases diagnosed, initiated on treatment, and completing treatment. The primary outcome was the incremental cost-effectiveness of point-of-care Xpert relative to smear microscopy. The study was performed from the perspective of the health-care provider.

FINDINGS

Using data from 1502 patients, we calculated that the mean Xpert unit cost was lower when performed at a centralised laboratory (Lab Xpert) rather than at point of care ($23·00 [95% CI 22·12-23·88] vs $28·03 [26·19-29·87]). Per 1000 patients screened, and relative to smear microscopy, point-of-care Xpert cost an additional $35 529 (27 054-40 025) and was associated with an additional 24·3 treatment initiations ([-20·0 to 68·5]; $1464 per treatment), 63·4 same-day treatment initiations ([27·3-99·4]; $511 per same-day treatment), and 29·4 treatment completions ([-6·9 to 65·6]; $1211 per completion). Xpert costs were most sensitive to test volume, whereas incremental outcomes were most sensitive to the number of patients initiating and completing treatment. The probability of point-of-care Xpert being cost-effective was 90% at a willingness to pay of $3820 per treatment completion.

INTERPRETATION

In southern Africa, although point-of-care Xpert unit cost is higher than Lab Xpert, it is likely to offer good value for money relative to smear microscopy. With the current availability of point-of-care nucleic acid amplification platforms (eg, Xpert Edge), these data inform much needed investment and resource allocation strategies in tuberculosis endemic settings.

FUNDING

European Union European and Developing Countries Clinical Trials Partnership.

Cost-Effectiveness Analysis of Xpert MTB/RIF for Multi-Outcomes of Patients With Presumptive Pulmonary Tuberculosis in Thailand

OBJECTIVES

The cost-effectiveness of screening adult patients for pulmonary tuberculosis is not clear. As such, this study aims to identify the cost-effectiveness between the Xpert MTB/RIF assay and the sputum acid-fast bacilli (AFB) smear. Multi-outcomes were correct diagnosis, time to achieve correct diagnosis, and gain in quality-adjusted life-years (QALYs).

METHODS

A decision tree model was constructed to reveal a possible clinical pathway of tuberculosis diagnosis. The researchers used a clinical study to establish the probability of all clinical pathways for input into this model. The sample size was calculated following the correct diagnosis. Participants were randomly divided into 2 groups. A structural questionnaire and the Thai version of quality of life (EQ-5D-5L) were used for interviewing.

RESULTS

The results showed that the time to achieve the correct diagnosis for the group using Xpert MTB/RIF was shorter than that for the group using the sputum AFB smear. Both the correct diagnosis and QALYs of the base case analysis presented the Xpert MTB/RIF method as dominant. A Monte Carlo model, which analyzed the Xpert MTB/RIF method, revealed that the average number of patients who were correctly diagnosed was 673, the QALYs were 945.85 years, and the total cost was $143 110.64. For the sputum AFB smear method, the average number who received a correct diagnosis was 592, the QALYs were 940.40 years, and the total cost was $196 666.84. Probabilistic and one-way sensitivity analysis confirmed that the Xpert MTB/RIF remained dominant.

CONCLUSIONS

These results provide useful information for the National Strategic Plan to screen all adult patients for pulmonary tuberculosis.

Cost-effectiveness analysis of Xpert in detecting Mycobacterium tuberculosis: A systematic review

OBJECTIVES

To report the cost-effectiveness of Xpert in detecting Mycobacterium tuberculosis (MTB) through a comprehensive systematic review.

METHODS

Specialized bibliographic databases were searched. Study quality was evaluated by commonly-used industry standards. Due to heterogeneity, evidences were synthesized narratively.

RESULTS

Four studies from intermediate-to-low tuberculosis (TB)-burdern areas and 17 studies from high-TB-burden areas were included. Smear microscopy, clinical diagnosis and chest radiography were mostly used for comparison. Cost elements varied considerably depending on the perspectives. Cost-effectiveness and cost-utility analyses were used by seven and fourteen studies, respectively. All studies were of high quality (CHEERS score of 78.4 and QHES score of 86.9). Average cost per test was 29.8 US$ for Xpert compared with 3.83 US$ for smear microscopy. Cost-effectiveness analyses mostly supported application of Xpert into areas under varying TB burdens.

CONCLUSIONS

Xpert seems cost-effective under respective willingness-to-pay thresholds in nations with differences in socioeconomy, HIV stress and geographical distribution. Nevertheless, policymakers will benefit from localized studies since regional economic/financial statuses and health-care system should also be considered apart from the reports of cost-effectiveness.

Effect of the Xpert MTB/RIF on the detection of pulmonary tuberculosis cases and rifampicin resistance in Shanghai, China

Background

Xpert MTB/RIF (Xpert) is an automated molecular test recommended by World Health Organization (WHO) for diagnosis of tuberculosis (TB). This study evaluated the effect of Xpert implementation on the detection of pulmonary TB (PTB) and rifampicin-resistant TB (RR-TB) cases in Shanghai, China.

Methods

Xpert was routinely implemented in 2018 for all presumptive PTB patients. All PTB patients above 15 years-old identified within the Provincial TB Control Program during the first half of each of 2017 and 2018, were enrolled to compare the difference in proportions of bacteriological confirmation, patients with drug susceptibility test (DST) results for rifampicin (ie, DST coverage) and RR-TB detection before and after Xpert’s implementation.

Results

A total of 6047 PTB patients were included in the analysis with 1691 tested by Xpert in 2018. Percentages of bacteriological confirmation, DST coverage and RR-TB detection in 2017 and 2018 were 50% vs. 59%, 36% vs. 49% and 2% vs. 3%, respectively (all p-values < 0.05). Among 1103 PTB patients who completed sputum smear, culture and Xpert testing in 2018, Xpert detected an additional 121 (11%) PTB patients who were negative by smear and culture, but missed 248 (23%) smear and/or culture positive patients. Besides, it accounted for an increase of 9% in DST coverage and 1% in RR-TB detection. The median time from first visit to a TB hospital to RR-TB detection was 62 days (interquartile range -IQR 48–84.2) in 2017 vs. 9 days (IQR 2–45.7) in 2018 (p-value < 0.001). In the multivariate model, using Xpert was associated with decreased time to RR-TB detection (adjusted hazard ratio = 4.62, 95% confidence interval: 3.18–6.71).

Conclusions

Integrating Xpert with smear, culture and culture-based DST in a routine setting significantly increased bacteriological confirmation, DST coverage and RR-TB detection with a dramatic reduction in the time to RR-TB diagnosis in Shanghai, China. Our findings can be useful for other regions that attempt to integrate Xpert into routine PTB and RR-TB case-finding cascade. Further study should focus on the identification and elimination of operational level challenges to fully utilize the benefit of rapid diagnosis by Xpert.

Standardized framework for evaluating costs of active case-finding programs: An analysis of two programs in Cambodia and Tajikistan

INTRODUCTION

Over the years, technological and process innovations enabled active case finding (ACF) programs to expand their capacities and scope to have evolved to close gaps in missing TB patients globally. However, with increased ACF program's operational complexity and a need for significant resource commitments, a comprehensive, transparent, and standardized approach in evaluating costs of ACF programs is needed to properly determine costs and value of ACF programs.

METHODS

Based on reviews of program activity and financial reports, multiple interviews with program managers of two TB REACH funded ACF programs deployed in Cambodia and Tajikistan, we first identified common program components, which formed the basis of the cost data collection, analysis, reporting framework. Within each program component and sub-activity group, cost data were collected and organized by relevant resource types (human resource, capital, recurrent, and overhead costs). Total shared, indirect and overhead costs were apportioned into each activity category based on direct human resource contribution (e.g. a number of staff and their relative level of effort dedicated to each program component). Capital assets were assessed specific to program components and were annualized based on their expected useful life and a 3% discount rate. All costs were assessed based on the service provider perspective and expressed in 2015 USD.

RESULTS

Over the two program years (April 2013 to December 2015), the Cambodia and Tajikistan ACF programs cumulated a total cost of $336,951 and $771,429 to screen 68,846 and 1,980,516 target population, bacteriologically test 4,589 and 19,764 presumptive TB, diagnose 731 and 2,246 TB patients in the respective programs. Recurrent costs were the largest cost components (54% and 34%) of the total costs for the respective programs and Xpert MTB/RIF (Xpert) testing incurred largest program component/activity cost for both programs. Cost per screening was $0.63 and $0.10 and cost per Xpert test was $25 and $18; Cost per TB case detected (Xpert) was $373 and $343 in Cambodia and Tajikistan.

CONCLUSIONS

Results from two contextually and programmatically different multi-component ACF programs demonstrate that our tool is fully capable of comprehensively and transparently evaluating and comparing costs of various ACF programs.

Diagnosis of tuberculosis from smear-negative presumptive TB cases using Xpert MTB/Rif assay: a cross-sectional study from Nepal

BACKGROUND

In most developing countries, smear-negative pulmonary TB (SNPT) often gets missed from the diagnosis of consideration, though it accounts 30-65% of total PTB cases, due to deficient or inaccessible molecular diagnostic modalities.

METHODS

The cross-sectional study enrolled 360 patients with clinical-radiological suspicion of SNPT in Tribhuvan University Teaching Hospital (TUTH). The patient selection was done as per the algorithm of Nepal's National Tuberculosis Program (NTP) for Xpert MTB/RIF testing. Participants' demographic and clinical information were collected using a pre-tested questionnaire. The specimens were collected, processed directly for Xpert MTB/RIF test according to the manufacturer's protocol. The same samples were stained using the Ziehl-Neelsen technique then observed microscopically. Both findings were interpreted; rifampicin-resistant, if obtained, on Xpert testing was confirmed with a Line Probe Assay.

RESULT

Of 360 smear-negative sputum samples analyzed, 85(23.61%) found positive while 3(0.8%) of them were rifampicin resistance. The infection was higher in males, i.e. 60(25.3%) compared to female 25(20.3%). The age group, > 45(nearly 33%) with median age 42 ± 21.5, were prone to the infection. During the study period, 4.6% (515/11048) sputum samples were reported as smear-positive in TUTH. Consequently, with Xpert MTB/RIF assay, the additional case 16.5% (n = 85/515) from smear-negative presumptive TB cases were detected. Among the most occurring clinical presentations, cough and chest pain were positively associated with SNPT. While upper lobe infiltrates (36.4%) and pleural effusion (40.4%) were the most peculiar radiological impression noted in PTB patient. 94 multi-drug resistant(MDR) suspected cases were enrolled; of total suspects, 29(30.8%) samples were rifampicin sensitive, 1(1.06%) indeterminate, 3(3.19%) rifampicin-resistant while remaining of them were negative. 2(2.2%) MDR cases were recovered from the patient with a previous history of ATT, of total 89 previously treated cases enrolled However, a single rifampicin-resistant from the new suspects.

CONCLUSION

With an application of the assay, the additional cases, missed with smear microscopy, could be sought and exact incidence of the diseases could be revealed.

Low diagnostic accuracy of Xpert MTB/RIF assay for extrapulmonary tuberculosis: A multicenter surveillance

Diagnostic accuracy of Xpert MTB/RIF assay for pulmonary tuberculosis (PTB) and extrapulmonary TB (EPTB) has not been investigated in Iran. This study was aimed to assess the diagnostic accuracy of Xpert MTB/RIF assay for both PTB and EPTB. A total of 2111 clinical samples (1218 pulmonary and 838 extra-pulmonary) were collected from 16 medical centers during the study period and were analyzed for detection of PTB and EPTB by both Xpert MTB/RIF assay and standard conventional methods (culture and direct smear microscopy). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of Xpert MTB/RIF assay for PTB were found to be 95.5%, 96.7%, 83.8%, and 99.1% respectively. For EPTB, the sensitivity, specificity, PPV and NPV of Xpert MTB/RIF assay counted for 76.5%, 95.9%, 62%, and 97.9% respectively. Xpert MTB/RIF assay found to be highly sensitive, specific and comparable to standard conventional methods for the diagnosis of PTB. However, the sensitivity and specificity of Xpert MTB/RIF for EPTB specimens were highly variable; thus, Xpert MTB/RIF cannot be recommended to replace standard conventional tests for diagnosis of EPTB.

Current situation and progress toward the 2030 health-related Sustainable Development Goals in China: A systematic analysis

BACKGROUND

The Sustainable Development Goals (SDGs), adopted by all United Nations (UN) member states in 2015, established a set of bold and ambitious health-related targets to achieve by 2030. Understanding China's progress toward these targets is critical to improving population health for its 1.4 billion people.

METHODS AND FINDINGS

We used estimates from the Global Burden of Disease (GBD) Study 2016, national surveys and surveillance data from China, and qualitative data. Twenty-eight of the 37 indicators included in the GBD Study 2016 were analyzed. We developed an attainment index of health-related SDGs, a scale of 0-100 based on the values of indicators. The projection model is adjusted based on the one developed by the GBD Study 2016 SDG collaborators. We found that China has achieved several health-related SDG targets, including decreasing neonatal and under-5 mortality rates and the maternal mortality ratios and reducing wasting and stunting for children. However, China may only achieve 12 out of the 28 health-related SDG targets by 2030. The number of target indicators achieved varies among provinces and municipalities. In 2016, among the seven measured health domains, China performed best in child nutrition and maternal and child health and reproductive health, with the attainment index scores of 93.0 and 91.8, respectively, followed by noncommunicable diseases (NCDs) (69.4), road injuries (63.6), infectious diseases (63.0), environmental health (62.9), and universal health coverage (UHC) (54.4). There are daunting challenges to achieve the targets for child overweight, infectious diseases, NCD risk factors, and environmental exposure factors. China will also have a formidable challenge in achieving UHC, particularly in ensuring access to essential healthcare for all and providing adequate financial protection. The attainment index of child nutrition is projected to drop to 80.5 by 2025 because of worsening child overweight. The index of NCD risk factors is projected to drop to 38.8 by 2025. Regional disparities are substantial, with eastern provinces generally performing better than central and western provinces. Sex disparities are clear, with men at higher risk of excess mortality than women. The primary limitations of this study are the limited data availability and quality for several indicators and the adoption of "business-as-usual" projection methods.

CONCLUSION

The study found that China has made good progress in improving population health, but challenges lie ahead. China has substantially improved the health of children and women and will continue to make good progress, although geographic disparities remain a great challenge. Meanwhile, China faced challenges in NCDs, mental health, and some infectious diseases. Poor control of health risk factors and worsening environmental threats have posed difficulties in further health improvement. Meanwhile, an inefficient health system is a barrier to tackling these challenges among such a rapidly aging population. The eastern provinces are predicted to perform better than the central and western provinces, and women are predicted to be more likely than men to achieve these targets by 2030. In order to make good progress, China must take a series of concerted actions, including more investments in public goods and services for health and redressing the intracountry inequities.

Diagnostic yield of active case finding for tuberculosis at human immunodeficiency virus testing in Haiti

SETTING: The Groupe Haïtien d'étude du Sarcome de Kaposi et des Infections Opportunistes (GHESKIO) Centres, Port-au-Prince, Haiti, facilitate "test and treat" strategies by screening all patients for tuberculosis (TB) at human immunodeficiency virus (HIV) testing.OBJECTIVE: 1) To determine the proportion of patients with chronic cough at HIV testing diagnosed with TB, stratified by HIV test results; and 2) to evaluate the additional diagnostic yield of Xpert® MTB/RIF vs. sputum microscopy.DESIGN: We conducted a retrospective cohort analysis including all adults tested for HIV at GHESKIO from August 2014 to July 2015.RESULTS: Of 29 233 adult patients tested for HIV, 2953 (10%) were diagnosed as HIV-positive. Chronic cough lasting ≥2 weeks was reported by 1116 (38%) HIV-positive patients; 984 (88%) were tested and 265 (27%) were diagnosed with TB. Chronic cough was reported by 5985 (23%) HIV-negative patients; 5654 (94%) were tested and 1179 (21%) were diagnosed with TB. Of all bacteriologically confirmed cases, 27% were smear-negative and Xpert-positive. Among all TB patients, 81% were HIV-negative.CONCLUSIONS: Screening for TB at HIV testing was high-yield, among both HIV-infected and HIV-negative individuals. Testing for both diseases should be conducted among patients who present with chronic cough at HIV testing.

Cost-effectiveness of Preventive Therapy for Tuberculosis With Isoniazid and Rifapentine Versus Isoniazid Alone in High-Burden Settings

Background

A short-course regimen of 3 months of weekly rifapentine and isoniazid (3HP) has recently been recommended by the World Health Organization as an alternative to at least 6 months of daily isoniazid (isoniazid preventive therapy [IPT]) for prevention of tuberculosis (TB). The contexts in which 3HP may be cost-effective compared to IPT among people living with human immunodeficiency virus are unknown.

Methods

We used a Markov state transition model to estimate the incremental cost-effectiveness of 3HP relative to IPT in high-burden settings, using a cohort of 1000 patients in a Ugandan HIV clinic as an emblematic scenario. Cost-effectiveness was expressed as 2017 US dollars per disability-adjusted life year (DALY) averted from a healthcare perspective over a 20-year time horizon. We explored the conditions under which 3HP would be considered cost-effective relative to IPT.

Results

Per 1000 individuals on antiretroviral therapy in the reference scenario, treatment with 3HP rather than IPT was estimated to avert 9 cases of TB and 1 death, costing $9402 per DALY averted relative to IPT. Cost-effectiveness depended strongly on the price of rifapentine, completion of 3HP, and prevalence of latent TB. At a willingness to pay of $1000 per DALY averted, 3HP is likely to be cost-effective relative to IPT only if the price of rifapentine can be greatly reduced (to approximately $20 per course) and high treatment completion (85%) can be achieved.

Conclusions

3HP may be a cost-effective alternative to IPT in high-burden settings, but cost-effectiveness depends on the price of rifapentine, achievable completion rates, and local willingness to pay.

Diagnostic Accuracy of Xpert MTB/RIF in Sputum Smear-Negative Pulmonary Tuberculosis

Introduction

Tuberculosis is a major health problem in Pakistan. The prevalence of pulmonary as well as extrapulmonary tuberculosis is quite high. Tuberculin skin test, radiological imaging, and sputum smear microscopy have limitations in the diagnosis of tuberculosis. Xpert MTB/RIF was recently approved for the diagnosis of pulmonary tuberculosis and has shown promising results. The aim of this study was to determine the diagnostic accuracy of Xpert MTB/RIF in sputum smear-negative pulmonary tuberculosis using acid-fast bacilli (AFB) culture as the gold standard.

Materials and methods

This cross-sectional study was conducted at Iqbal Yad Chest Clinic and Nazimabad Chest Clinic of Ojha Institute of Chest Diseases, Dow University of Health Sciences. Patients of either gender aged 18-65 years suspected to have pulmonary tuberculosis with at least two sputum samples negative for AFB underwent Xpert MTB/RIF testing. Early morning sputum samples were obtained and sent for AFB smear microscopy, Xpert testing and also for culture analysis.

Results

Mean age of the patients was 37.48 ±17.49 years. There were 84 (37.3%) females and 141 (62.7%) males. Positive findings on Xpert MTB/RIF were found in 147 (65.3%) patients whereas AFB culture showed positive findings in 174 (77.3%) patients. Sensitivity, specificity, positive predicted value, negative predicted value and overall diagnostic accuracy of Xpert MTB/RIF was found to be 84.48%, 100%, 100%, 65.38%, and 88%, respectively.

Conclusion

Xpert MTB/RIF has high sensitivity, specificity, and diagnostic accuracy in diagnosis of sputum smear-negative cases of pulmonary tuberculosis.

Informing decision-making for universal access to quality tuberculosis diagnosis in India: an economic-epidemiological model

BACKGROUND

India and many other high-burden countries have committed to providing universal access to high-quality diagnosis and drug susceptibility testing (DST) for tuberculosis (TB), but the most cost-effective approach to achieve this goal remains uncertain. Centralized testing at district-level hub facilities with a supporting sample transport network can generate economies of scale, but decentralization to the peripheral level may provide faster diagnosis and reduce losses to follow-up (LTFU).

METHODS

We generated functions to evaluate the costs of centralized and decentralized molecular testing for tuberculosis with Xpert MTB/RIF (Xpert), a WHO-endorsed test which can be performed at centralized and decentralized levels. We merged the cost estimates with an agent-based simulation of TB transmission in a hypothetical representative region in India to assess the impact and cost-effectiveness of each strategy.

RESULTS

Compared against centralized Xpert testing, decentralization was most favorable when testing volume at decentralized facilities and pre-treatment LTFU were high, and specimen transport network was exclusively established for TB. Assuming equal quality of centralized and decentralized testing, decentralization was cost-saving, saving a median $338,000 (interquartile simulation range [IQR] - $222,000; $889,000) per 20 million people over 10 years, in the most cost-favorable scenario. In the most cost-unfavorable scenario, decentralized testing would cost a median $3161 [IQR $2412; $4731] per disability-adjusted life year averted relative to centralized testing.

CONCLUSIONS

Decentralization of Xpert testing is likely to be cost-saving or cost-effective in most settings to which these simulation results might generalize. More decentralized testing is more cost-effective in settings with moderate-to-high peripheral testing volumes, high existing clinical LTFU, inability to share specimen transport costs with other disease entities, and ability to ensure high-quality peripheral Xpert testing. Decision-makers should assess these factors when deciding whether to decentralize molecular testing for tuberculosis.