Lessons from a decade of adult vaccine rollout in low- and middle-income countries: a scoping review.

INTRODUCTION: The historical focus of vaccines on child health coupled with the advent of novel vaccines targeting adult populations necessitates exploring strategies for adult vaccine implementation. AREAS COVERED: This scoping review extracts insights from the past decade's experiences introducing adult vaccines in low- and middle-income countries. Among 25 papers reviewed, 19 focused on oral cholera vaccine, 2 on Meningococcal A vaccines, 2 on tetanus toxoid vaccine, 1 on typhoid vaccine, and 1 on Ebola vaccine. Aligned with WHO's Global Framework for New TB Vaccines for Adults and Adolescents, our findings center on vaccine availability, accessibility, and acceptance. EXPERT OPINION: Availability findings underscore the importance of understanding disease burden for prioritization, multi-sectoral collaboration during planning, and strategic resource allocation and coordination. Accessibility results highlight the benefits of leveraging existing health infrastructure and adequately training healthcare workers, and contextually tailoring vaccine delivery approaches to reach challenging sub-groups like working male adults. Central to fostering acceptance, resonant sensitization, and communication campaigns engaging the communities and utilizing trusted local leaders countered rumors and increased awareness and uptake. As we approach the introduction of a new adult TB vaccine, insights from this review equips decision-makers with key evidence-based recommendations to support successful and equitable vaccinations targeting adults.

How to eradicate polio in Pakistan: Insights from community health workers.

Pakistan, along with Afghanistan, is one of two countries where wild poliovirus is still endemic. Frontline workers (FLWs) are the staff most intimately familiar with both implementation challenges and community context. Harnessing their expertise may be a way to improve the community-polio program interface, which has been a persistent and shifting challenge in polio-endemic areas of both countries. From 2020-2022, we engaged frontline workers in 18 Super High-Risk Union Councils (SHRUCs) in Pakistan through a Human-Centered Design ideas competition. In that competition, teams of polio FLWs identified the most significant barriers they faced in conducting their work, and suggested solutions to those problems-a window into the issues the program faces by the people who know it best. The suggestions of FLWs on how to eradicate polio fell into four main categories. First, there were suggestions to tackle community fatigue by reducing touchpoints, particularly visits solely for data collection. Second, there were calls to improve Primary Health Care in SHRUCs, as a way of addressing community frustrations over an intense focus on just one disease in the context of numerous acute needs. Third, there were suggested ways to increase community engagement through locally relevant channels. Finally, many workers suggested improvements to Human Resources processes and workplace dynamics. Across these ideas, one repeated concept is the need for balance between the intensity of polio activities required for eradication and the provision of other government services, including health services. FLWs engaged the process deeply, providing well thought out problem statements and ideas for change. It is our view that there is no one more qualified to speak to the issues on the ground than FLWs. There are critical insights available if we listen to people who are instrumental to the success of health programs, but not commonly involved with creating policy.

Breaking the silence on gendered harassment and assault of community health workers: an analysis of ethnographic studies.

INTRODUCTION: Across a variety of settings, women in tenuous financial circumstances are drawn to community health work as a way to advance themselves in the context of limited employment options. Female Community Health Workers (CHWs) are often preferred because they can more easily access mothers and children; at the same time, gender norms are at the heart of many of the challenges and inequities that these workers encounter. Here, we explore how these gender roles and a lack of formal worker protections leave CHWs vulnerable to violence and sexual harassment, common occurrences that are frequently downplayed or silenced. METHODS: We are a group of researchers who work on CHW programmes in a variety of contexts globally. The examples here are drawn from our ethnographic research (participant observation and in-depth interviews). RESULTS: CHW work creates job opportunities for women in contexts where such opportunities are extremely rare. These jobs can be a lifeline for women with few other options. Yet the threat of violence can be very real: women may face violence from the community, and some experience harassment from supervisors within health programmes. CONCLUSION: Taking gendered harassment and violence seriously in CHW programmes is critical for research and practice. Fulfilling CHWs' vision of health programmes that value them, support them and give them opportunities may be a way for CHW programmes to lead the way in gender-transformative labour practices.

Artificial intelligence-reported chest X-ray findings of culture-confirmed pulmonary tuberculosis in people with and without diabetes.

Objectives: We applied computer-aided detection (CAD) software for chest X-ray (CXR) analysis to determine if diabetes affects the radiographic presentation of tuberculosis. Methods: From March 2017-July 2018, we consecutively enrolled adults being evaluated for pulmonary tuberculosis in Karachi, Pakistan. Participants had same-day CXR, two sputum mycobacterial cultures, and random blood glucose measurement. We identified diabetes through self-report or glucose >11.1mMol/L. We included participants with culture-confirmed tuberculosis for this analysis. We used linear regression to estimate associations between CAD-reported tuberculosis abnormality score (range 0.00 to 1.00) and diabetes, adjusting for age, body mass index, sputum smear-status, and prior tuberculosis. We also compared radiographic abnormalities between participants with and without diabetes. Results: 63/272 (23%) of included participants had diabetes. After adjustment, diabetes was associated with higher CAD tuberculosis abnormality scores (p < 0.001). Diabetes was not associated with frequency of CAD-reported radiographic abnormalities apart from cavitary disease; participants with diabetes were more likely to have cavitary disease (74.6% vs 61.2% p = 0.07), particularly non-upper zone cavitary disease (17% vs 7.8%, p = 0.09). Conclusions: CAD analysis of CXR suggests diabetes is associated with more extensive radiographic abnormalities and with greater likelihood of cavities outside upper lung zones.

Diagnostic accuracy of a commercially available, deep learning-based chest X-ray interpretation software for detecting culture-confirmed pulmonary tuberculosis.

BACKGROUND: Few evaluations of computer-aided detection (CAD) software for analyzing chest radiographs for tuberculosis have used mycobacterial culture as the reference standard. METHODS: Using data from a prospective study of symptomatic adults and household contacts of persons with tuberculosis who were seeking care in Karachi, we evaluated the accuracy of LUNIT INSIGHT version 3.1.0.0 (LUNIT, South Korea) for detecting pulmonary tuberculosis in the triage use case. The reference standard was liquid culture. We estimated the diagnostic accuracy using three developer-recommended threshold scores for tuberculosis: 15, 30, and 45. RESULTS: A total 269 of 2190 (12%) participants had culture-confirmed pulmonary tuberculosis. LUNIT-reported abnormalities of nodule, consolidation, fibrosis, and pleural effusion were more common with culture-confirmed tuberculosis. At the tuberculosis threshold score of 30, sensitivity and specificity were, respectively, 87.7% [95% CI: 83.2-91.4%] and 64.3% [62.1-66.4%]. Sensitivity was similar at scores of 15, 88.1% [95% CI: 83.6-91.7%] and 45, 86.6% [82.0 - 90.5%]; and specificity was 57.9% [55.7-60.2%] and 69.9% [67.8-71.9%], respectively. Sensitivity was lower for smear-negative disease, and specificity was lower with increasing age, previous tuberculosis, and decreasing body mass index. Diabetes and tobacco smoking did not modify accuracy. CONCLUSION: In a population where most tuberculosis was smear-positive, LUNIT-reported radiographic abnormalities were associated with culture-confirmed disease. Manufacturer-recommended threshold scores had limited sensitivity.

Chest X-ray Analysis With Deep Learning-Based Software as a Triage Test for Pulmonary Tuberculosis: An Individual Patient Data Meta-Analysis of Diagnostic Accuracy.

BACKGROUND: Automated radiologic analysis using computer-aided detection software (CAD) could facilitate chest X-ray (CXR) use in tuberculosis diagnosis. There is little to no evidence on the accuracy of commercially available deep learning-based CAD in different populations, including patients with smear-negative tuberculosis and people living with human immunodeficiency virus (HIV, PLWH). METHODS: We collected CXRs and individual patient data (IPD) from studies evaluating CAD in patients self-referring for tuberculosis symptoms with culture or nucleic acid amplification testing as the reference. We reanalyzed CXRs with three CAD programs (CAD4TB version (v) 6, Lunit v3.1.0.0, and qXR v2). We estimated sensitivity and specificity within each study and pooled using IPD meta-analysis. We used multivariable meta-regression to identify characteristics modifying accuracy. RESULTS: We included CXRs and IPD of 3727/3967 participants from 4/7 eligible studies. 17% (621/3727) were PLWH. 17% (645/3727) had microbiologically confirmed tuberculosis. Despite using the same threshold score for classifying CXR in every study, sensitivity and specificity varied from study to study. The software had similar unadjusted accuracy (at 90% pooled sensitivity, pooled specificities were: CAD4TBv6, 56.9% [95% confidence interval {CI}: 51.7-61.9]; Lunit, 54.1% [95% CI: 44.6-63.3]; qXRv2, 60.5% [95% CI: 51.7-68.6]). Adjusted absolute differences in pooled sensitivity between PLWH and HIV-uninfected participants were: CAD4TBv6, -13.4% [-21.1, -6.9]; Lunit, +2.2% [-3.6, +6.3]; qXRv2: -13.4% [-21.5, -6.6]; between smear-negative and smear-positive tuberculosis was: were CAD4TBv6, -12.3% [-19.5, -6.1]; Lunit, -17.2% [-24.6, -10.5]; qXRv2, -16.6% [-24.4, -9.9]. Accuracy was similar to human readers. CONCLUSIONS: For CAD CXR analysis to be implemented as a high-sensitivity tuberculosis rule-out test, users will need threshold scores identified from their own patient populations and stratified by HIV and smear status.

Triage of Persons With Tuberculosis Symptoms Using Artificial Intelligence-Based Chest Radiograph Interpretation: A Cost-Effectiveness Analysis.

BACKGROUND: In settings without access to rapid expert radiographic interpretation, artificial intelligence (AI)-based chest radiograph (CXR) analysis can triage persons presenting with possible tuberculosis (TB) symptoms, to identify those who require additional microbiological testing. However, there is limited evidence of the cost-effectiveness of this technology as a triage tool. METHODS: A decision analysis model was developed to evaluate the cost-effectiveness of triage strategies with AI-based CXR analysis for patients presenting with symptoms suggestive of pulmonary TB in Karachi, Pakistan. These strategies were compared to the current standard of care using microbiological testing with smear microscopy or GeneXpert, without prior triage. Positive triage CXRs were considered to improve referral success for microbiologic testing, from 91% to 100% for eligible persons. Software diagnostic accuracy was based on a prospective field study in Karachi. Other inputs were obtained from the Pakistan TB Program. The analysis was conducted from the healthcare provider perspective, and costs were expressed in 2020 US dollars. RESULTS: Compared to upfront smear microscopy for all persons with presumptive TB, triage strategies with AI-based CXR analysis were projected to lower costs by 19%, from $23233 per 1000 persons, and avert 3%-4% disability-adjusted life-years (DALYs), from 372 DALYs. Compared to upfront GeneXpert, AI-based triage strategies lowered projected costs by 37%, from $34346 and averted 4% additional DALYs, from 369 DALYs. Reinforced follow-up for persons with positive triage CXRs but negative microbiologic tests was particularly cost-effective. CONCLUSIONS: In lower-resource settings, the addition of AI-based CXR triage before microbiologic testing for persons with possible TB symptoms can reduce costs, avert additional DALYs, and improve TB detection.

Measuring fidelity to delivery of a new smoking cessation intervention integrated into routine tuberculosis care in Pakistan and Bangladesh: Contextual differences and opportunities.

INTRODUCTION: Tobacco smoking among tuberculosis (TB) patients leads to poorer treatment outcomes. Smoking cessation support should be integrated into routine TB care. We measured healthcare providers' fidelity to a smoking cessation intervention integrated into routine TB care, in Bangladesh and Pakistan. We aimed to understand the role of providers and settings in the implementation of behavior support (BS) messages for TB and smoking cessation. METHODS: The integrated BS intervention was implemented in TB clinics (24 public and 1 private). Cross-sectional data were collected on the fidelity of delivery of the BS intervention using a predefined fidelity index based on an existing validated method of measuring intervention fidelity. Audio-recordings of patient-provider BS sessions were coded using the fidelity index. Intervention fidelity was presented as the proportion of sessions that implemented BS messages. RESULTS: A total of 96 sessions were conducted, 37 in Bangladesh and 59 in Pakistan. In public settings, TB medication advice was offered in 91.9% (95% CI: 78.7- 97.2) of sessions in Bangladesh, and in 75.5% (95% CI: 62.4-85.1) of sessions in Pakistan; whilst it was offered in 83.3% (95% CI: 43.7-97.0) of sessions in the private setting in Pakistan. Patients' smoking status was assessed in 70.3% (95% CI: 54.2-82.5) of sessions in Bangladesh, and in 34.0% (95% CI: 22.7-47.4) of sessions in the public setting and in 66.7% (95% CI: 30.0-90.3) of sessions in the private setting in Pakistan. A quit date was set in 32.4% (95% CI: 19.6-48.5) of all sessions in Bangladesh, and in 33.3% (95% CI: 9.6-70.0) of all sessions in the public setting in Pakistan. CONCLUSIONS: Fidelity to the intended delivery of the intervention was found to be high for TB-related messages but not for smoking cessation messages. Clinic contexts may play a mediating role in health workers' opportunities to deliver the intervention as planned. TRIAL REGISTRATION: International Standard Randomized Clinical Trial Number (ISRCTN43811467). Registered 23 March 2016, https://doi.org/10.1186/ISRCTN43811467.

Cost of Delivering 12-Dose Isoniazid and Rifapentine Versus 6 Months of Isoniazid for Tuberculosis Infection in a High-Burden Setting.

BACKGROUND: Successful delivery and completion of tuberculosis preventive treatment are necessary for tuberculosis elimination. Shorter preventive treatment regimens currently have higher medication costs, but patients spend less time in care and are more likely to complete treatment. It is unknown how economic costs of successful delivery differ between longer and shorter regimens in high-tuberculosis-burden settings. METHODS: We developed survey instruments to collect costs from program and patient sources, considering costs incurred from when household contacts first entered the health system. We compared the cost per completed course of preventive treatment with either 6 months of daily isoniazid (6H) or 3 months of weekly isoniazid and rifapentine (3HP), delivered by the Indus Health Network tuberculosis program in Karachi, Pakistan, between October 2016 and February 2018. RESULTS: During this period, 459 individuals initiated 6H and 643 initiated 3HP; 39% and 61% completed treatment, respectively. Considering costs to both the program and care recipients, the cost per completed course was 394 US dollars (USD) for 6H and 333 USD for 3HP. Using a new 2020 price for rifapentine reduced the cost per completed course of 3HP to 290 USD. Under varying assumptions about drug prices and costs incurred by care recipients, the cost per completed course was lower for 3HP in all scenarios, and the largest cost drivers were the salaries of clinical staff. CONCLUSIONS: In a high-burden setting, the cost of successful delivery of 3HP was lower than that of 6H, driven by higher completion.

Chest x-ray analysis with deep learning-based software as a triage test for pulmonary tuberculosis: a prospective study of diagnostic accuracy for culture-confirmed disease.

BACKGROUND: Deep learning-based radiological image analysis could facilitate use of chest x-rays as triage tests for pulmonary tuberculosis in resource-limited settings. We sought to determine whether commercially available chest x-ray analysis software meet WHO recommendations for minimal sensitivity and specificity as pulmonary tuberculosis triage tests. METHODS: We recruited symptomatic adults at the Indus Hospital, Karachi, Pakistan. We compared two software, qXR version 2.0 (qXRv2) and CAD4TB version 6.0 (CAD4TBv6), with a reference of mycobacterial culture of two sputa. We assessed qXRv2 using its manufacturer prespecified threshold score for chest x-ray classification as tuberculosis present versus not present. For CAD4TBv6, we used a data-derived threshold, because it does not have a prespecified one. We tested for non-inferiority to preset WHO recommendations (0·90 for sensitivity, 0·70 for specificity) using a non-inferiority limit of 0·05. We identified factors associated with accuracy by stratification and logistic regression. FINDINGS: We included 2198 (92·7%) of 2370 enrolled participants. 2187 (99·5%) of 2198 were HIV-negative, and 272 (12·4%) had culture-confirmed pulmonary tuberculosis. For both software, accuracy was non-inferior to WHO-recommended minimum values (qXRv2 sensitivity 0·93 [95% CI 0·89-0·95], non-inferiority p=0·0002; CAD4TBv6 sensitivity 0·93 [0·90-0·96], p<0·0001; qXRv2 specificity 0·75 [0·73-0·77], p<0·0001; CAD4TBv6 specificity 0·69 [0·67-0·71], p=0·0003). Sensitivity was lower in smear-negative pulmonary tuberculosis for both software, and in women for CAD4TBv6. Specificity was lower in men and in those with previous tuberculosis, and reduced with increasing age and decreasing body mass index. Smoking and diabetes did not affect accuracy. INTERPRETATION: In an HIV-negative population, these software met WHO-recommended minimal accuracy for pulmonary tuberculosis triage tests. Sensitivity will be lower when smear-negative pulmonary tuberculosis is more prevalent. FUNDING: Canadian Institutes of Health Research.