An evaluation of systematic tuberculosis screening at private facilities in Karachi, Pakistan

Background

In Pakistan, like many Asian countries, a large proportion of healthcare is provided through the private sector. We evaluated a systematic screening strategy to identify people with tuberculosis in private facilities in Karachi and assessed the approaches' ability to diagnose patients earlier in their disease progression.

Methods and Findings

Lay workers at 89 private clinics and a large hospital outpatient department screened all attendees for tuberculosis using a mobile phone-based questionnaire during one year. The number needed to screen to detect a case of tuberculosis was calculated. To evaluate early diagnosis, we tested for differences in cough duration and smear grading by screening facility. 529,447 people were screened, 1,010 smear-positive tuberculosis cases were detected and 942 (93.3%) started treatment, representing 58.7% of all smear-positive cases notified in the intervention area. The number needed to screen to detect a smear-positive case was 124 (prevalence 806/100,000) at the hospital and 763 (prevalence 131/100,000) at the clinics; however, ten times the number of individuals were screened in clinics. People with smear-positive TB detected at the hospital were less likely to report cough lasting 2–3 weeks (RR 0.66 95%CI [0.49–0.90]) and more likely to report cough duration >3 weeks (RR 1.10 95%CI [1.03–1.18]). Smear-positive cases at the clinics were less likely to have a +3 grade (RR 0.76 95%CI [0.63–0.92]) and more likely to have +1 smear grade (RR 1.24 95%CI [1.02–1.51]).

Conclusions

Tuberculosis screening at private facilities is acceptable and can yield large numbers of previously undiagnosed cases. Screening at general practitioner clinics may find cases earlier than at hospitals although more people must be screened to identify a case of tuberculosis. Limitations include lack of culture testing, therefore underestimating true TB prevalence. Using more sensitive and specific screening and diagnostic tests such as chest x-ray and Xpert MTB/RIF may improve results.

An Innovative Public-Private Mix Model for Improving Tuberculosis Care in Vietnam: How Well are We Doing?

To improve tuberculosis (TB) care among individuals attending a private tertiary care hospital in Vietnam, an innovative private sector engagement model was implemented from June to December 2018. This included: (i) Active facility-based screening of all adults for TB symptoms (and chest x-ray (CXR) for those with symptoms) by trained and incentivized providers, with on-site diagnostic testing or transport of sputum samples, (ii) a mobile application to reduce dropout in the care cascade and (iii) enhanced follow-up care by community health workers. We conducted a cohort study using project and routine surveillance data for evaluation. Among 52,078 attendees, 368 (0.7%) had symptoms suggestive of TB and abnormalities on CXR. Among them, 299 (81%) were tested and 103 (34.4%) were diagnosed with TB. In addition, 195 individuals with normal CXR were indicated for TB testing by attending clinicians, of whom, seven were diagnosed with TB. Of the 110 TB patients diagnosed, 104 (95%) were initiated on treatment and 97 (93%) had a successful treatment outcome. Given the success of this model, the National TB Programme is considering to scale it up nationwide after undertaking a detailed cost-effectiveness analysis.

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.

Early Evaluation of an Ultra-Portable X-ray System for Tuberculosis Active Case Finding

X-ray screening is an important tool in tuberculosis (TB) prevention and care, but access has historically been restricted by its immobile nature. As recent advancements have improved the portability of modern X-ray systems, this study represents an early evaluation of the safety, image quality and yield of using an ultra-portable X-ray system for active case finding (ACF). We reported operational and radiological performance characteristics and compared image quality between the ultra-portable and two reference systems. Image quality was rated by three human readers and by an artificial intelligence (AI) software. We deployed the ultra-portable X-ray alongside the reference system for community-based ACF and described TB care cascades for each system. The ultra-portable system operated within advertised specifications and radiologic tolerances, except on X-ray capture capacity, which was 58% lower than the reported maximum of 100 exposures per charge. The mean image quality rating from radiologists for the ultra-portable system was significantly lower than the reference (3.71 vs. 3.99, p < 0.001). However, we detected no significant differences in TB abnormality scores using the AI software (p = 0.571), nor in any of the steps along the TB care cascade during our ACF campaign. Despite some shortcomings, ultra-portable X-ray systems have significant potential to improve case detection and equitable access to high-quality TB care.

The impact of chest radiography and Xpert MTB/RIF testing among household contacts in Chennai, India

Tuberculosis prevalence surveys have demonstrated the benefit of screening with chest x-ray (CXR) and sensitive diagnostic tests compared to symptoms and smear microscopy. However, in programmatic practice there is little evidence on the yield of different algorithms. We implemented contact tracing in Chennai, India for adult sputum-positive TB patients registered from January 2015 to March 2016. Patients with symptoms or abnormal X-ray findings further underwent testing using Xpert MTB/RIF (Xpert) and smear microscopy. A retrospective cohort study was done to summarize the key findings. We verbally screened 5553 contacts for symptoms, CXR through private sector collaboration, Xpert, and smear microscopy. Overall, 1312 (23.6%) contacts screened positive. CXR alone identified 531 (40.5%) of them, 679 (51.8%) were symptom-positive only, while 102 (7.8%) were positive on both the symptom and CXR screen. Overall, 35 bacteriologically positive cases were identified (0.7%). A standard approach of symptoms screening followed by microscopy identified only 9 (25.7%) of the total number of bacteriologically positive cases, whereas the combination of a CRX screening followed by microscopy identified 13 (37.1%) of the cases. The algorithm of symptoms screening followed by Xpert testing, detected 20 cases, whereas the combination of symptoms and CXR followed by Xpert increased this number to 35 (75% increase compared to symptoms and Xpert). Optimal use of more sensitive screening tests, better diagnostic tests, and novel private sector engagement can improve diagnostic yield in a programmatic setting.

Costs and operation management of community outreach program for tuberculosis in tribal populations in India

Objective

To evaluate costs of an active case finding (ACF) program with tuberculosis (TB) treatment delivery and monitoring, which targeted a rural tribal population in India.

Method

A time and motion study was conducted to evaluate operations and workload. Costs from the program perspective were assessed using both the bottom-up and top-down costing methods, exclusive of routine TB care costs. The impact of ACF on routine TB laboratory workloads was measured based on the changes in available staff time per smear at nine designated microscopy centers before and after program implementation.

Results

A majority (53.2%) of the community health-care worker's time was spent in traveling to communities, with an average of 22 TB patients (95% CI 19.14-24.94) seen per day per person. Costs (at 2015 $US rates) were US$1.85-US$2.42 per patient screened and submitting sputum, US$2.51-US$4.74 per person diagnosed with TB, and US$22.52-US$34.13 per TB patient completing treatment. Total smear volumes increased significantly after the ACF program, with more than a 15% reduction in available staff time per sputum smear test in most laboratories.

Conclusion

This low-cost, ACF program has the potential to be highly cost-effective in addressing gaps in TB care problems in rural India.

Finding the missed millions: innovations to bring tuberculosis diagnosis closer to key populations

Current strategies to promptly, effectively, and equitably screen people with tuberculosis (TB) and link them to diagnosis and care are insufficient; new approaches are required to find the millions of people around the world with TB who are missed each year. Interventions also need to be designed considering how people interact with health care facilities and where appropriate should be suitable for use in the community. Here, the historical, new, and reemerging technologies that are being utilised for TB diagnosis globally are discussed, whilst highlighting that how we use and evaluate tests is just as important as the tests themselves.

What matters most? A qualitative study exploring priorities for supportive interventions for people with tuberculosis in urban Viet Nam

INTRODUCTION

The health and economic burden of tuberculosis (TB) in urban Viet Nam is high. Social protection and support interventions can improve treatment outcomes and reduce costs. However, evidence regarding optimal strategies in this context is lacking. This study aimed to increase understanding of what people with TB and healthcare providers (HCPs) perceive as important to improve TB treatment outcomes and reduce costs.

METHODS

We conducted qualitative focus group discussions (seven groups, n=30) and key informant interviews (n=4) with people with drug-susceptible and multidrug-resistant TB and HCPs in Ha Noi and Ho Chi Minh City. Topic guides covered perspectives on and prioritisation of different forms of social protection and support. Data were analysed using reflexive thematic analysis and interpreted using a Framework for Transformative Social Protection.

RESULTS

We identified three themes and seven subthemes. The first theme, 'Existing financial safety nets are essential, but could go further to support people affected by TB', highlights that support to meet the medical costs of TB treatment and flexible cash transfers are a priority for people with TB and HCPs. The second, 'It is important to promote "physical and spiritual health" during TB treatment', demonstrates that extended psychosocial and nutritional support would encourage people with TB during their treatment. The third, 'Accessibility and acceptability are critical in designing social support interventions for people with TB', shows the importance of ensuring that support is accessible and proportional to the needs of people with TB and their families.

CONCLUSIONS

Accessible interventions that incorporate financial risk protection, nutritional and psychosocial support matter most to people with TB and HCPs in urban Viet Nam to improve their treatment outcomes and reduce catastrophic costs. This study can inform the design of stronger person-centred interventions to advance progress towards the goals of the WHO's End TB Strategy.

Comparative performance evaluation of QIAreach QuantiFERON-TB and tuberculin skin test for diagnosis of tuberculosis infection in Viet Nam

Current WHO-recommended diagnostic tools for tuberculosis infection (TBI) have well-known limitations and viable alternatives are urgently needed. We compared the diagnostic performance and accuracy of the novel QIAreach QuantiFERON-TB assay (QIAreach; index) to the QuantiFERON-TB Gold Plus assay (QFT-Plus; reference). The sample included 261 adults (≥ 18 years) recruited at community-based TB case finding events. Of these, 226 underwent Tuberculin Skin Tests and 200 returned for interpretation (TST; comparator). QIAreach processing and TST reading were completed at lower-level healthcare facilities. We conducted matched-pair comparisons for QIAreach and TST with QFT-Plus, calculated sensitivity, specificity and area under a receiver-operating characteristic curve (AUC), and analyzed concordant-/discordant-pair interferon-gamma (IFN-γ) levels. QIAreach sensitivity and specificity were 98.5% and 72.3%, respectively, for an AUC of 0.85. TST sensitivity (53.2%) at a 5 mm induration threshold was significantly below QIAreach, while specificity (82.4%) was statistically equivalent. The corrected mean IFN-γ level of 0.08 IU/ml and corresponding empirical threshold (0.05) of false-positive QIAreach results were significantly lower than the manufacturer-recommended QFT-Plus threshold (≥ 0.35 IU/ml). Despite QIAreach's higher sensitivity at equivalent specificity to TST, the high number of false positive results and low specificity limit its utility and highlight the continued need to expand the diagnostic toolkit for TBI.

Study protocol: diagnostic accuracy study comparing Cy-Tb and STANDARD F TB-Feron FIA tests for tuberculosis infection diagnosis in Vietnam

INTRODUCTION

The large reservoir of tuberculosis (TB) infections is one of the main reasons for the persistent incidence of TB. Accurate diagnostic tests are crucial to correctly identify and treat people with TB infection, which is vital to eliminate TB globally. The rdESAT-6 and rCFP-10 (Cy-Tb) injection ('Cy-Tb'), a TB-specific antigen skin test and STANDARD F TB-Feron FIA ('Standard F TB') measuring interferon-gamma by fluorescence immunoassay assay are two novel tools for the diagnosis of TB infection which offer advantages compared with current tests in low-resource settings and reduced costs to both health systems and TB-affected people. The proposed study aims to evaluate the diagnostic accuracy of these two new tests for TB infection diagnosis.

METHODS AND ANALYSIS

This cross-sectional study aims to assess the diagnostic accuracy for TB infection of the Cy-Tb skin test and Standard F TB assay (investigational tests) compared with the QuantiFERON-TB Gold Plus (QFT-Plus) assay as the immunological reference standard. Three different cohorts of study participants will be recruited at the Vietnam National Lung Hospital: adults with bacteriologically confirmed pulmonary TB (n=100), household contacts of people with TB (n=200) and people without TB infection (n=50). All consenting participants will undergo simultaneous testing with Cy-Tb, Standard F TB and QFT-Plus. The primary endpoint is the diagnostic accuracy of the Cy-Tb skin test and Standard F TB assay, expressed as sensitivity and specificity against the reference standard.

ETHICS AND DISSEMINATION

Ethical approval was granted by the Vietnam National Lung Hospital Institutional Review Board (65/23/CN-HDDD-BVPTU) and the Swedish Ethical Review Authority (Dnr 2023-04271-01). Study results will be disseminated to the scientific community and policymakers through scientific publications.

TRIAL REGISTRATION NUMBER

NCT06221735.

Optimising diagnosis and treatment of tuberculosis infection in community and primary care settings in two urban provinces of Viet Nam: a cohort study

OBJECTIVES

To end tuberculosis (TB), the vast reservoir of 1.7-2.3 billion TB infections (TBIs) must be addressed, but achieving global TB preventive therapy (TPT) targets seems unlikely. This study assessed the feasibility of using interferon-γ release assays (IGRAs) at lower healthcare levels and the comparative performance of 3-month and 9-month daily TPT regimens (3HR/9H).

DESIGN, SETTING, PARTICIPANTS AND INTERVENTION

This cohort study was implemented in two provinces of Viet Nam from May 2019 to September 2020. Participants included household contacts (HHCs), vulnerable community members and healthcare workers (HCWs) recruited at community-based TB screening events or HHC investigations at primary care centres, who were followed up throughout TPT.

PRIMARY AND SECONDARY OUTCOMES

We constructed TBI care cascades describing indeterminate and positivity rates to assess feasibility, and initiation and completion rates to assess performance. We fitted mixed-effects logistic and stratified Cox models to identify factors associated with IGRA positivity and loss to follow-up (LTFU).

RESULTS

Among 5837 participants, the indeterminate rate was 0.8%, and 30.7% were IGRA positive. TPT initiation and completion rates were 63.3% (3HR=61.2% vs 9H=63.6%; p=0.147) and 80.6% (3HR=85.7% vs 9H=80.0%; p=0.522), respectively. Being male (adjusted OR=1.51; 95% CI: 1.28 to 1.78; p<0.001), aged 45-59 years (1.30; 1.05 to 1.60; p=0.018) and exhibiting TB-related abnormalities on X-ray (2.23; 1.38 to 3.61; p=0.001) were associated with positive IGRA results. Risk of IGRA positivity was lower in periurban districts (0.55; 0.36 to 0.85; p=0.007), aged <15 years (0.18; 0.13 to 0.26; p<0.001), aged 15-29 years (0.56; 0.42 to 0.75; p<0.001) and HCWs (0.34; 0.24 to 0.48; p<0.001). The 3HR regimen (adjusted HR=3.83; 1.49 to 9.84; p=0.005) and HCWs (1.38; 1.25 to 1.53; p<0.001) showed higher hazards of LTFU.

CONCLUSION

Providing IGRAs at lower healthcare levels is feasible and along with shorter regimens may expand access and uptake towards meeting TPT targets, but scale-up may require complementary advocacy and education for beneficiaries and providers.