Programmatic approaches to screening for active tuberculosis [State of the art series. Active case finding/screening. Number 6 in the series]

Community views on active case finding for tuberculosis in low- and middle-income countries: a qualitative evidence synthesis

BACKGROUND

Active case finding (ACF) refers to the systematic identification of people with tuberculosis in communities and amongst populations who do not present to health facilities, through approaches such as door-to-door screening or contact tracing. ACF may improve access to tuberculosis diagnosis and treatment for the poor and for people remote from diagnostic and treatment facilities. As a result, ACF may also reduce onward transmission. However, there is a need to understand how these programmes are experienced by communities in order to design appropriate services.

OBJECTIVES

To synthesize community views on tuberculosis active case finding (ACF) programmes in low- and middle-income countries.

SEARCH METHODS

We searched MEDLINE, Embase, and eight other databases up to 22 June 2023, together with reference checking, citation searching, and contact with study authors to identify additional studies. We did not include grey literature.

SELECTION CRITERIA

This review synthesized qualitative research and mixed-methods studies with separate qualitative data. Eligible studies explored community experiences, perceptions, or attitudes towards ACF programmes for tuberculosis in any endemic low- or middle-income country, with no time restrictions.

DATA COLLECTION AND ANALYSIS

Due to the large volume of studies identified, we chose to sample studies that had 'thick' description and that investigated key subgroups of children and refugees. We followed standard Cochrane methods for study description and appraisal of methodological limitations. We conducted thematic synthesis and developed codes inductively using ATLAS.ti software. We examined codes for underlying ideas, connections, and interpretations and, from this, generated analytical themes. We assessed the confidence in the findings using the GRADE-CERQual approach, and produced a conceptual model to display how the different findings interact.

MAIN RESULTS

We included 45 studies in this synthesis, and sampled 20. The studies covered a broad range of World Health Organization (WHO) regions (Africa, South-East Asia, Eastern Mediterranean, and the Americas) and explored the views and experiences of community members, community health workers, and clinical staff in low- and middle-income countries endemic for tuberculosis. The following five themes emerged. • ACF improves access to diagnosis for many, but does little to help communities on the edge. Tuberculosis ACF and contact tracing improve access to health services for people with worse health and fewer resources (High confidence). ACF helps to find this population, exposed to deprived living conditions, but is not sensitive to additional dimensions of their plight (High confidence) and out-of-pocket costs necessary to continue care (High confidence). Finally, migration and difficult geography further reduce communities' access to ACF (High confidence). • People are afraid of diagnosis and its impact. Some community members find screening frightening. It exposes them to discrimination along distinct pathways (isolation from their families and wider community, lost employment and housing). HIV stigma compounds tuberculosis stigma and heightens vulnerability to discrimination along these same pathways (High confidence). Consequently, community members may refuse to participate in screening, contact tracing, and treatment (High confidence). In addition, people with tuberculosis reported their emotional turmoil upon diagnosis, as they anticipated intense treatment regimens and the prospect of living with a serious illness (High confidence). • Screening is undermined by weak health infrastructure. In many settings, a lack of resources results in weak services in competition with other disease control programmes (Moderate confidence). In this context of low investment, people face repeated tests and clinic visits, wasted time, and fraught social interaction with health providers (Moderate confidence). ACF can create expectations for follow-up health care that it cannot deliver (High confidence). Finally, community education improves awareness of tuberculosis in some settings, but lack of full information impacts community members, parents, and health workers, and sometimes leads to harm for children (High confidence). • Health workers are an undervalued but important part of ACF. ACF can feel difficult for health workers in the context of a poorly resourced health system and with people who may not wish to be identified. In addition, the evidence suggests health workers are poorly protected against tuberculosis and fear they or their families might become infected (Moderate confidence). However, they appear to be central to programme success, as the humanity they offer often acts as a driving force for retaining people with tuberculosis in care (Moderate confidence). • Local leadership is necessary but not sufficient for ensuring appropriate programmes. Local leadership creates an intrinsic motivation for communities to value health services (High confidence). However, local leadership cannot guarantee the success of ACF and contact tracing programmes. It is important to balance professional authority with local knowledge and rapport (High confidence).

AUTHORS' CONCLUSIONS

Tuberculosis active case finding (ACF) and contact tracing bring a diagnostic service to people who may otherwise not receive it, such as those who are well or without symptoms and those who are sick but who have fewer resources and live further from health facilities. However, capturing these 'missing cases' may in itself be insufficient without appropriate health system strengthening to retain people in care. People who receive a tuberculosis diagnosis must contend with a complex and unsustainable cascade of care, and this affects their perception of ACF and their decision to engage with it.

Yield of Facility-based Targeted Universal Testing for Tuberculosis With Xpert and Mycobacterial Culture in High-Risk Groups Attending Primary Care Facilities in South Africa

BACKGROUND

We report the yield of targeted universal tuberculosis (TB) testing of clinic attendees in high-risk groups.

METHODS

Clinic attendees in primary healthcare facilities in South Africa with one of the following risk factors underwent sputum testing for TB: human immunodeficiency virus (HIV), contact with a TB patient in the past year, and having had TB in the past 2 years. A single sample was collected for Xpert-Ultra (Xpert) and culture. We report the proportion positive for Mycobacterium tuberculosis. Data were analyzed descriptively. The unadjusted clinical and demographic factors' relative risk of TB detected by culture or Xpert were calculated and concordance between Xpert and culture is described.

RESULTS

A total of 30 513 participants had a TB test result. Median age was 39 years, and 11 553 (38%) were men. The majority (n = 21734, 71%) had HIV, 12 492 (41%) reported close contact with a TB patient, and 1573 (5%) reported prior TB. Overall, 8.3% were positive for M. tuberculosis by culture and/or Xpert compared with 6.0% with trace-positive results excluded. In asymptomatic participants, the yield was 6.7% and 10.1% in symptomatic participants (with trace-positives excluded). Only 10% of trace-positive results were culture-positive. We found that 55% of clinic attendees with a sputum result positive for M. tuberculosis did not have a positive TB symptom screen.

CONCLUSIONS

A high proportion of clinic attendees with specific risk factors (HIV, close TB contact, history of TB) test positive for M. tuberculosis when universal testing is implemented.

Computer-aided interpretation of chest radiography reveals the spectrum of tuberculosis in rural South Africa

Computer-aided digital chest radiograph interpretation (CAD) can facilitate high-throughput screening for tuberculosis (TB), but its use in population-based active case-finding programs has been limited. In an HIV-endemic area in rural South Africa, we used a CAD algorithm (CAD4TBv5) to interpret digital chest x-rays (CXR) as part of a mobile health screening effort. Participants with TB symptoms or CAD4TBv5 score above the triaging threshold were referred for microbiological sputum assessment. During an initial pilot phase, a low CAD4TBv5 triaging threshold of 25 was selected to maximize TB case finding. We report the performance of CAD4TBv5 in screening 9,914 participants, 99 (1.0%) of whom were found to have microbiologically proven TB. CAD4TBv5 was able to identify TB cases at the same sensitivity but lower specificity as a blinded radiologist, whereas the next generation of the algorithm (CAD4TBv6) achieved comparable sensitivity and specificity to the radiologist. The CXRs of people with microbiologically confirmed TB spanned a range of lung field abnormality, including 19 (19.2%) cases deemed normal by the radiologist. HIV serostatus did not impact CAD4TB's performance. Notably, 78.8% of the TB cases identified during this population-based survey were asymptomatic and therefore triaged for sputum collection on the basis of CAD4TBv5 score alone. While CAD4TBv6 has the potential to replace radiologists for triaging CXRs in TB prevalence surveys, population-specific piloting is necessary to set the appropriate triaging thresholds. Further work on image analysis strategies is needed to identify radiologically subtle active TB.

Active case-finding of tuberculosis in general populations and at-risk groups: a systematic review and meta-analysis

The World Health Organization (WHO) recommends active case-finding (ACF) of Tuberculosis (TB) in certain high-risk groups; however, more evidence is needed to elucidate the scope of ACF beyond the current recommendations. In this study we aimed to systematically review yields (the prevalence of active TB) of studies on ACF in general populations and at-risk groups.The review protocol was registered with PROSPERO (registration no.: CRD42020206856). A literature search in PubMed, Embase, and CENTRAL was performed for studies concluded after 31/12/1999 and published before 01/09/2020. Screening yields were estimated and yield/prevalence ratios (ratio between yield of study and WHO estimated prevalence of TB) were calculated to assess which groups might especially benefit from ACF. Finally, risk of bias was assessed, and heterogeneity was investigated using meta-regression and sensitivity analyses.We included 197 studies, with a total of 12 372 530 screened and 53 158 cases found. Yields were high among drug users, close contacts, the poor and marginalised, people living with HIV (PLHIV), and prison inmates across incidence strata and estimated yield/prevalence ratios in screenings of general populations tended to be >1 with an overall ratio of 1.4 and ranging between 1.0 and 1.5. Sensitivity analyses suggested that inclusion of studies at high risk of bias contributed to underestimation of yields.Despite many studies using insensitive screening methods, these results suggest that more at-risk groups should be considered for inclusion in future screening recommendations and that screening of general populations may outperform current case-finding practices, providing evidence for extending ACF beyond the current recommendations.

'A double-edged sword': Perceived benefits and harms of active case-finding for people with presumptive tuberculosis and communities-A qualitative study based on expert interviews

BACKGROUND

Active case-finding (ACF), also referred to as community-based tuberculosis screening, is a component of the World Health Organization's End TB Strategy. ACF has potential benefits but also harms, which need to be carefully assessed when developing and implementing ACF policies. While empirical evidence on the benefits of ACF is still weak, evidence on the harms is even weaker. This study aimed to explore experts' views on the benefits and harms of ACF for people with presumptive TB and communities.

METHODS

This was an exploratory study. Semi-structured interviews were conducted with a purposive sample of 39 experts from international, non-governmental/non-profit organizations, funders, government institutions, international societies, think tanks, universities and research institutions worldwide. Framework analysis was applied.

RESULTS

Findings elaborated perceived benefits of ACF, including reaching vulnerable populations, reducing patient costs, helping raise awareness for tuberculosis among individuals and engaging communities, and reducing tuberculosis transmission. Perceived harms included increasing stigma and discrimination, causing false-positive diagnoses, as well as triggering other unintended consequences related to screening for tuberculosis patients, such as deportation of migrants once confirmed to have tuberculosis. Most of the perceived benefits of ACF could be linked to its objective of finding and treating persons with tuberculosis early (theme 1), while ACF was also perceived as a "double-edged sword" and could cause harms, if inappropriately designed and implemented (theme 2). The analysis underlined the importance of considering the benefits and harms of ACF throughout the screening pathway. The study provides new insights into the perceived benefits and harms of ACF from the perspectives of experts in the field.

CONCLUSION

This study highlights gaps in the evidence base surrounding ACF and can stimulate further research, debate and analysis regarding the benefits and harms of ACF to inform contextual optimization of design and implementation of ACF strategies.

Improving tuberculosis management in prisons: Impact of a rapid molecular point-of-care test

OBJECTIVE

To improve tuberculosis (TB) diagnosis in prison, we evaluate the value of the Xpert^ⓇMTB/RIF Ultra assay (Xpert) as point-of-care (POC) in a French prison hospital.

METHODS

We first validated Xpert use on raw sputum at the referent laboratory. Secondly, trained physicians at the prison hospital performed Xpert tests for each patient presenting TB symptoms. The results were compared with Xpert, microscopic examination, culture and drug susceptibility testing on the corresponding decontaminated specimens.

RESULTS

76 inmates were included in 15 months and 21 were diagnosed with TB. The overall sensitivity, specificity, positive and negative predictive values of Xpert were respectively: 92.3%, 100%, 100% and 98.7% on raw sputum. The efficiency of the molecular POC was confirmed by a concordance of 97% between Xpert findings from the prison hospital and culture results. Delay of microbiological diagnosis was reduced by about 18 days for 13 inmates with smear-negative sputum that avoid the mobilization of major means (escort, transport) to perform fibroscopic samples. Repeated Xpert negative results helped to speed the lifting of inmate isolation.

CONCLUSIONS

The implementation of Xpert in prison could optimize the management of incarcerated patients and thus limit the spread of TB among inmates, carers and other staff.

Active case-finding policy development, implementation and scale-up in high-burden countries: A mixed-methods survey with National Tuberculosis Programme managers and document review

BACKGROUND

The World Health Organization (WHO) stresses the importance of active case-finding (ACF) for early detection of tuberculosis (TB), especially in the 30 high-burden countries that account for almost 90% of cases globally.

OBJECTIVE

To describe the attitudes of National TB Programme (NTP) managers related to ACF policy development, implementation and scale-up in the 30 high-burden countries, and to review national TB strategic plans.

METHODS

This was a mixed-methods study with an embedded design: A cross-sectional survey with NTP managers yielded quantitative and qualitative data. A review of national TB strategic plans complemented the results. All data were analyzed in parallel and merged in the interpretation of the findings.

RESULTS

23 of the 30 NTP managers (77%) participated in the survey and 22 (73%) national TB strategic plans were reviewed. NTP managers considered managers in districts and regions key stakeholders for both ACF policy development and implementation. Different types of evidence were used to inform ACF policy, while there was a particular demand for local evidence. The NSPs reflected the NTP managers' unanimous agreement on the need for ACF scale-up, but not all included explicit aims and targets related to ACF. The NTP managers recognized that ACF may decrease health systems costs in the long-term, while acknowledging the risk for increased health system costs in the short-term. About 90% of the NTP managers declared that financial and human resources were currently lacking, while they also elaborated on strategies to overcome resource constraints.

CONCLUSION

NTP managers stated that ACF should be scaled up but reported resource constraints. Strategies to increase resources exist but may not yet have been fully implemented, e.g. generating local evidence including from operational research for advocacy. Managers in districts and regions were identified as key stakeholders whose involvement could help improve ACF policy development, implementation and scale-up.

The TB REACH Initiative: Supporting TB Elimination Efforts in the Asia-Pacific

After many years of TB 'control' and incremental progress, the TB community is talking about ending the disease, yet this will only be possible with a shift in the way we approach the TB response. While the Asia-Pacific region has the highest TB burden worldwide, it also has the opportunity to lead the quest to end TB by embracing the four areas laid out in this series: using data to target hotspots, initiating active case finding, provisioning preventive TB treatment, and employing a biosocial approach. The Stop TB Partnership's TB REACH initiative provides a platform to support partners in the development, evaluation and scale-up of new and innovative technologies and approaches to advance TB programs. We present several approaches TB REACH is taking to support its partners in the Asia-Pacific and globally to advance our collective response to end TB.

Role of community health workers in improving cost efficiency in an active case finding tuberculosis programme: an operational research study from rural Bihar, India

OBJECTIVES

Cost-efficient active case finding (ACF) approaches are needed for their large-scale adoption in national tuberculosis (TB) programmes. Our aim was to assess if community health workers' (CHW) knowledge about families' health status can improve the cost efficiency of the ACF programme without adversely affecting the delivery of other health services for which they are responsible.

DESIGN

Quasi-experimental design.

INTERVENTIONS

We evaluated an ACF programme in the Samastipur district in Bihar, India, between July 2017 and June 2018. CHWs called Accredited Social Health Activists generated referrals of individuals at risk of TB and conducted symptom-based screening to identify patients with presumptive TB. They also helped them undergo testing and provided treatment support for confirmed TB cases.

PRIMARY AND SECONDARY OUTCOME MEASURES

We compared the notification rate from the intervention region with that from a control region in the same district with similar characteristics. We analysed operational data to calculate the cost per TB case diagnosed. We used routine programmatic data from the public health system to estimate the impact on other services provided by CHWs.

FINDINGS

CHWs identified 9895 patients with presumptive TB. Of these, 5864 patients were tested for TB, and 1236 were confirmed as TB cases. Annual public case notification rate increased sharply in the intervention region from 45.8 to 105.8 per 100 000 population, whereas it decreased from 50.7 to 45.3 in the control region. There was no practically or statistically significant impact on other output indicators of the CHWs, such as institutional deliveries (-0.04%). The overall cost of the intervention was about US$134 per diagnosed case. Main cost drivers were human resources, and commodities (drugs and diagnostics), which contributed 37.4% and 32.5% of the cost, respectively.

CONCLUSIONS

ACF programmes that use existing CHWs in the health system are feasible, cost efficient and do not adversely affect other healthcare services delivered by CHWs.

Impact of Advocacy, Communication, Social Mobilization and Active Case Finding on TB Notification in Jharkhand, India

Community-level benefits of screening for active tuberculosis (TB) disease remain uncertain. Project Axshya (meaning free of TB) conducted advocacy, communication, social mobilization, and active case finding among vulnerable/marginalized populations of India. Among 15 districts of Jharkhand state, the project was initiated in 36 subdistrict level administrative units - tuberculosis units (TUs) in a staggered manner between April 2013 and September 2014, and continued till the end of 2015. Seven TUs did not implement the project. We assessed the relative change in the quarterly TB case finding indicators (n = 4) after inclusion of a TU within the project. By fitting four multilevel models (mixed-effects maximum likelihood regression using random intercept), we adjusted for secular (over previous five quarters) and seasonal trends, baseline differences within Axshya and non-Axshya TUs, and population size and clustering within districts and within TUs. After inclusion of a TU within the project, we found a significant increase [95% confidence interval (CI)] in TU-level presumptive TB sputum examination rate, new sputum-positive TB Case Notification Rate (CNR), sputum-positive TB CNR, and all forms TB CNR by 12 (5.5, 18.5), 1.1 (0.5, 1.7), 1.3 (0.6, 2.0), and 1.2 (0.1, 2.2) per 100,000 population per quarter, respectively. Overall, the project resulted in an increase (95% CI) in sputum examination and detection of new sputum-positive TB, sputum-positive TB and all forms of TB patients by 22,410 (10,203, 34,077), 2066 (923, 3210), 2380 (1162, 3616), and 2122 (203, 4059), respectively. This provides evidence for implementing project Axshya over and above the existing passive case finding.

Finding gaps in TB notifications: spatial analysis of geographical patterns of TB notifications, associations with TB program efforts and social determinants of TB risk in Bangladesh, Nepal and Pakistan

BACKGROUND

In order to effectively combat Tuberculosis, resources to diagnose and treat TB should be allocated effectively to the areas and population that need them. Although a wealth of subnational data on TB is routinely collected to support local planning, it is often underutilized. Therefore, this study uses spatial analytical techniques and profiling to understand and identify factors underlying spatial variation in TB case notification rates (CNR) in Bangladesh, Nepal and Pakistan for better TB program planning.

METHODS

Spatial analytical techniques and profiling was used to identify subnational patterns of TB CNRs at the district level in Bangladesh (N = 64, 2015), Nepal (N = 75, 2014) and Pakistan (N = 142, 2015). A multivariable linear regression analysis was performed to assess the association between subnational CNR and demographic and health indicators associated with TB burden and indicators of TB programme efforts. To correct for spatial dependencies of the observations, the residuals of the multivariable models were tested for unexplained spatial autocorrelation. Spatial autocorrelation among the residuals was adjusted for by fitting a simultaneous autoregressive model (SAR).

RESULTS

Spatial clustering of TB CNRs was observed in all three countries. In Bangladesh, TB CNR were found significantly associated with testing rate (0.06%, p < 0.001), test positivity rate (14.44%, p < 0.001), proportion of bacteriologically confirmed cases (- 1.33%, p < 0.001) and population density (4.5*10-3%, p < 0.01). In Nepal, TB CNR were associated with population sex ratio (1.54%, p < 0.01), facility density (- 0.19%, p < 0.05) and treatment success rate (- 3.68%, p < 0.001). Finally, TB CNR in Pakistan were found significantly associated with testing rate (0.08%, p < 0.001), positivity rate (4.29, p < 0.001), proportion of bacteriologically confirmed cases (- 1.45, p < 0.001), vaccination coverage (1.17%, p < 0.001) and facility density (20.41%, p < 0.001).

CONCLUSION

Subnational TB CNRs are more likely reflective of TB programme efforts and access to healthcare than TB burden. TB CNRs are better used for monitoring and evaluation of TB control efforts than the TB epidemic. Using spatial analytical techniques and profiling can help identify areas where TB is underreported. Applying these techniques routinely in the surveillance facilitates the use of TB CNRs in program planning.

Active versus passive case finding for tuberculosis in marginalised and vulnerable populations in India: comparison of treatment outcomes

Background: Community-based active case finding (ACF) for tuberculosis (TB) implemented among marginalised and vulnerable populations in 285 districts of India resulted in reduction of diagnosis delay and prevalence of catastrophic costs due to TB diagnosis. We were interested to know whether this translated into improved treatment outcomes. Globally, there is limited published literature from marginalised and vulnerable populations on the independent effect of community-based ACF on treatment outcomes when compared to passive case finding (PCF).

Objectives: To determine the relative differences in unfavourable treatment outcomes (death, loss-to-follow-up, failure, not evaluated) of ACF and PCF-diagnosed people.

Methods: Cohort study involving record reviews and interviews in 18 randomly selected districts. We enrolled all ACF-diagnosed people with new smear-positive pulmonary TB, registered under the national TB programme between March 2016 and February 2017, and an equal number of randomly selected PCF-diagnosed people in the same settings. We used log binomial models to adjust for confounders.

Results: Of 572 enrolled, 275 belonged to the ACF and 297 to the PCF group. The proportion of unfavourable outcomes were 10.2% (95% CI: 7.1%, 14.3%) in the ACF and 12.5% (95% CI: 9.2%, 16.7%) in the PCF group (p = 0.468). The association between ACF and unfavourable outcomes remained non-significant after adjusting for confounders available from records [aRR: 0.83 (95% CI: 0.56, 1.21)]. Due to patient non-availability at their residence, interviews were conducted for 465 (81.3%). In the 465 cohort too, there was no association after adjusting for confounders from records and interviews [aRR: 1.05 (95% CI: 0.62, 1.77)].

Conclusion: We did not find significant differences in the treatment outcomes. Due to the wide CIs, studies with larger sample sizes are urgently required. Studies are required to understand how to translate the benefits of ACF to improved treatment outcomes.

A comparison of the yield and relative cost of active tuberculosis case-finding algorithms in Zimbabwe

Setting

Ten districts and three cities in Zimbabwe.

Objective

To compare the yield and relative cost of identifying a case of tuberculosis (TB) using the three WHO-recommended algorithms (WHO2b, symptom inquiry only; WHO2d, chest X-ray [CXR] after a positive symptom inquiry; WHO3b, CXR only) and the Zimbabwe active case finding (ZimACF) algorithm (symptom inquiry plus CXR) to everyone.

Design

Cross-sectional study using data from the ZimACF project.

Results

A total of 38 574 people were screened from April to December 2017; 488 (1.3%) were diagnosed with TB using the ZimACF algorithm. Fewer TB cases would have been diagnosed with the WHO-recommended algorithms. This ranged from 7% fewer (34 cases) with WHO3b, 18% fewer (88 cases) with WHO2b and 25% fewer (122 cases) with WHO2d. The need for CXR ranged from 36% (WHO2d) to 100% (WHO3b). The need for bacteriological confirmation ranged from 7% (WHO2d) to 40% (ZimACF). The relative cost per case of TB diagnosed ranged from US$180 with WHO3b to US$565 for the ZimACF algorithm.

Conclusion

The ZimACF algorithm had the highest case yield, but at a much higher cost per case than the WHO algorithms. It is possible to switch to algorithm WHO3b, but the trade-off between cost and yield needs to be reviewed by the Zimbabwean National TB Programme.

Patient characteristics, health seeking and delays among new sputum smear positive TB patients identified through active case finding when compared to passive case finding in India

Background

Axshya SAMVAD is an active tuberculosis (TB) case finding (ACF) strategy under project Axshya (Axshya meaning ‘free of TB’ and SAMVAD meaning ‘conversation’) among marginalized and vulnerable populations in 285 districts of India.

Objectives

To compare patient characteristics, health seeking, delays in diagnosis and treatment initiation among new sputum smear positive TB patients detected through ACF and passive case finding (PCF) under the national TB programme in marginalized and vulnerable populations between March 2016 and February 2017.

Methods

This observational analytic study was conducted in 18 randomly sampled Axshya districts. We enrolled all TB patients detected through ACF and an equal number of randomly selected patients detected through PCF in the same settings. Data on patient characteristics, health seeking and delays were collected through record review and patient interviews (at their residence). Delays included patient level delay (from eligibility for sputum examination to first contact with any health care provider (HCP)), health system level diagnosis delay (from contact with first HCP to TB diagnosis) and treatment initiation delays (from diagnosis to treatment initiation). Total delay was the sum of patient level, health system level diagnosis delay and treatment initiation delays.

Results

We included 234 ACF-diagnosed and 231 PCF-diagnosed patients. When compared to PCF, ACF patients were relatively older (≥65 years, 14% versus 8%, p = 0.041), had no formal education (57% versus 36%, p<0.001), had lower monthly income per capita (median 13.1 versus 15.7 USD, p = 0.014), were more likely from rural areas (92% versus 81%, p<0.002) and residing far away from the sputum microscopy centres (more than 15 km, 24% versus 18%, p = 0.126). Fewer patients had history of significant loss of weight (68% versus 78%, p = 0.011) and sputum grade of 3+ (15% versus 21%, p = 0.060). Compared to PCF, HCP visits among ACF patients was significantly lower (median one versus two HCPs, p<0.001). ACF patients had significantly lower health system level diagnosis delay (median five versus 19 days, p = 0.008) and the association remained significant after adjusting for potential confounders. Patient level and total delays were not significantly different.

Conclusion

Axshya SAMVAD linked the most impoverished communities to TB care and resulted in reduction of health system level diagnosis delay.

The performance and yield of tuberculosis testing algorithms using microscopy, chest x-ray, and Xpert MTB/RIF

Setting

The introduction of Xpert MTB/RIF (Xpert) and renewed interest in chest x-ray (CXR) for tuberculosis testing has provided additional choices to the smear-based diagnostic algorithms used by TB programs previously. More programmatic data is needed to better understand the implications of possible approaches.

Objective

We sought to evaluate how different testing algorithms using microscopy, Xpert and CXR impacted the number of people detected with TB in a district hospital in Nepal.

Design

Consecutively recruited patients with TB-related symptoms were offered smear microscopy, CXR and Xpert. We tested six hypothetical algorithms and compared yield, bacteriologically positive (Bac+) cases missed, and tests conducted.

Results

Among 929 patients, Bac+ prevalence was 17.3% (n = 161). Smear microscopy detected 121 (75.2% of Bac+). Depending on the radiologists' interpretation of CXR, Xpert testing could be reduced by (31%-60%). Smear microscopy reduced Xpert cartridge need slightly, but increased the overall diagnostic tests performed.

Conclusion

Xpert detected a large proportion of Bac+ TB cases missed by microscopy. CXR was useful in greatly reducing the number of diagnostic tests needed even among presumptive TB patients. Loose CXR readings should be used to identify more people for TB testing. More analysis of costs and standardized CXR reading should be considered.

Are scientific research outputs aligned with national policy makers' priorities? A case study of tuberculosis in Cambodia

With funding for tuberculosis (TB) research decreasing, and the high global disease burden persisting, there are calls for increased investment in TB research. However, justification of such investments is questionable, when translation of research outputs into policy and health care improvements remains a challenge for TB and other diseases. Using TB in Cambodia as a case study, we investigate how evidence needs of national policy makers are addressed by topics covered in research publications. We first conducted a systematic review to compile all studies on TB in Cambodia published since 2000. We then identified priority areas in which evidence for policy and programme planning are required from the perspective of key national TB control stakeholders. Finally, results from the literature review were analysed in relation to the priority research areas for national policy makers to assess overlap and highlight gaps in evidence. Priority research areas were: TB-HIV co-infection; childhood TB; multidrug resistant TB (MDR-TB); and universal and equitable access to quality diagnosis and treatment. On screening 1687 unique papers retrieved from our literature search, 253 were eligible publications focusing on TB in Cambodia. Of these, only 73 (29%) addressed one of the four priority research areas. Overall, 30 (11%), five (2%), seven (2%) and 37 (14%) studies reported findings relevant to TB-HIV, childhood TB, MDR-TB and access to quality diagnosis and treatment respectively. Our analysis shows that a small proportion of the research outputs in Cambodia address priority areas for informing policy and programme planning. This case study illustrates that there is substantial room for improvement in alignment between research outputs and evidence gaps that national policy makers would like to see addressed; better coordination between researchers, funders and policy makers' on identifying priority research topics may increase the relevance of research findings to health policies and programmes.

Efficacy of district tuberculosis co-ordinating team on health service performance for suspected TB patient in district hospital

Purpose

The purpose of this paper is to study the efficacy of a district tuberculosis (TB) co-ordinating team on health service performance for suspected TB patients in a district hospital in northeastern Thailand.

Design/methodology/approach

A comparison study of pre- and post-evaluations of TB system improvement was conducted in a district hospital in northeastern Thailand between October 2016 and June 2017. Data collection reviewed the record of suspected TB cases reported in the district hospital in the past nine months as a base line for describing the health service performance in term of received investigation for TB diagnosis. Participants from a TB clinic, district health office and health center set up a TB co-ordinating team to explore situations and systematic gaps. The TB co-ordinating team gave recommendations of health service performance for suspected TB patients over a nine-month period. Records of suspected TB cases health service performance were collected nine months after intervention. Data analysis by descriptive statistics and to test the effect of intervention was performed.

Findings

The records from 324 and 379 suspected TB cases reported in the hospital from the 9 months preceding and 9 months, respectively, after intervention were reviewed. A TB co-ordinating team was set up to improve the system and health service performance in terms of investigation for TB diagnosis. The results revealed that health service performance in terms of complete microscopy and investigation in both chest radiography and microscopy increased after intervention. When comparing between pre- and post-intervention, suspected cases received both chest radiography and microscopy in 176 cases and 283 cases, respectively (p-value=0.001). There were 27 cases diagnosed for smear positive TB in pre-intervention and 51 cases diagnosed in post-intervention (p-value=0.011). There were 21 cases pre- and 36 cases post-intervention that had referral documents from health center with no statistically significant difference.

Originality/value

The TB co-ordinating team had the role to improve health service performance for suspected TB cases to enroll in investigation process for increase TB diagnosis in district hospital.

The prevalence and determinants of active tuberculosis among diabetes patients in Cape Town, South Africa, a high HIV/TB burden setting

AIMS

Studies addressing the association between diabetes mellitus (DM) and tuberculosis (TB) in sub-Saharan Africa are limited. We assessed the prevalence of active TB among DM patients at a primary care clinic, and identified risk factors for prevalent TB.

METHODS

A cross-sectional study was conducted in adult DM patients attending a clinic in Khayelitsha, Cape Town. Participants were screened for active TB (symptom screening and microbiological diagnosis) and HIV.

RESULTS

Among 440 DM patients screened, the active TB prevalence was 3.0% (95% CI 1.72-5.03). Of the 13 prevalent TB cases, 53.9% (n = 7; 95% CI 27.20-78.50) had no TB symptoms, and 61.5% (n = 8; 95% CI 33.30-83.70) were HIV-1 co-infected. There were no significant differences in either fasting plasma glucose or HbA_1c levels between TB and non-TB participants. On multivariate analysis, HIV-1 infection (OR 11.3, 95% CI 3.26-39.42) and hemoptysis (OR 31.4, 95% CI 3.62-273.35) were strongly associated with prevalent active TB, with no differences in this association by age or gender.

CONCLUSIONS

The prevalence of active TB among DM patients was 4-fold higher than the national prevalence; suggesting the need for active TB screening, particularly if hemoptysis is reported. Our results highlight the importance of HIV screening in this older population group. The high prevalence of sub-clinical TB among those diagnosed with TB highlights the need for further research to determine how best to screen for active TB in high-risk TB/HIV population groups and settings.

Household contact non-attendance of clinical evaluation for tuberculosis: a pilot study in a high burden district in South Africa

Background

In 2012, the World Health Organization launched guidelines for systematically investigating contacts of persons with infectious tuberculosis (TB) in low- and middle-income countries. As such, it is necessary to understand factors that would influence successful scale-up. This study targeted household contacts of newly-diagnosed infectious TB patients in the Mangaung Metropolitan district to explore factors associated with non-attendance of clinical evaluation.

Method

In September–October 2016, a pilot study of household contacts was conducted. At each of the 40 primary health care (PHC) facilities in the district, at least one out of four types of TB index cases were purposefully selected. These included children <5 years, smear-positive cases, HIV co-infected cases, and multidrug-resistant TB (MDR-TB) cases. Trained fieldworkers administered questionnaires and screened contacts for TB symptoms. Those with TB symptoms as well as children <5 years were referred for clinical evaluation at the nearest PHC facility. Contacts’ socio-demographic and clinical characteristics, TB knowledge and perception about TB-related discrimination are described. Logistic regression analysis was used to investigate factors associated with non-attendance of clinical evaluation.

Results

Out of the 259 participants, approximately three in every five (59.5%) were female. The median age was 20 (interquartile range: 8–41) years. While the large majority (87.3%) of adult contacts correctly described TB aetiology, almost three in every five (59.9%) thought that it was hereditary, and almost two-thirds (65.5%) believed that it could be cured by herbal medicine. About one-fifth (22.9%) of contacts believed that TB patients were subjected to discrimination. Two in every five (39.4%) contacts were referred for clinical evaluation of whom more than half (52.9%) did not attend the clinic. Non-attendance was significantly associated with inter alia male gender (AOR: 3.4; CI: 1.11–10.24), prior TB diagnosis (AOR: 5.6; CI: 1.13–27.90) and sharing of a bedroom with the index case (AOR: 3.4: CI: 1.07–10.59).

Conclusion

The pilot study identified gaps in household contacts’ knowledge of TB. Further research on important individual, clinical and structural factors that can influence and should be considered in the planning, implementation and scale-up of household contact TB investigation is warranted.

Diagnostic yield of active case finding for tuberculosis and HIV at the household level in slums in Haiti

SETTING

Haiti has the highest burden of tuberculosis (TB) in the Americas, with an estimated prevalence of 254 per 100 000 population. The Haitian Group for the Study of Kaposi's Sarcoma and Opportunistic Infections (Groupe Haïtien d'Etude du Sarcome de Kaposi et des Infections Opportunistes, GHESKIO) conducted active case finding (ACF) for TB at the household level in nine slums in Port-au-Prince.

OBJECTIVE

We report on the prevalence of undiagnosed TB detected through GHESKIO's ACF campaign.

DESIGN

From 1 August 2014 to 31 July 2015, we conducted a retrospective cohort analysis using GHESKIO's ACF campaign data. All individuals who reported chronic cough (cough 2 weeks) were tested for TB at GHESKIO, and those aged 10 years were included in the analyses.

RESULTS

Of 104 097 individuals screened in the community, 5598 (5%) reported chronic cough and satisfied the study inclusion criteria. A total of 1110 (20%) were diagnosed with active TB disease (prevalence of 1066/100 000). Of the 5472 (98%) patients tested for human immunodeficiency virus (HIV), 528 (10%) were HIV-positive; 143 (3%) patients were diagnosed with both diseases.

CONCLUSION

Household-level screening for cough with TB and HIV testing for symptomatic patients was a high-yield strategy, leading to the detection of a prevalence of undiagnosed disease exceeding national estimates by more than four-fold for TB, and by five-fold for HIV.

Tuberculosis active case finding in Cambodia: a pragmatic, cost-effectiveness comparison of three implementation models

BACKGROUND

Globally, almost 40% of tuberculosis (TB) patients remain undiagnosed, and those that are diagnosed often experience prolonged delays before initiating correct treatment, leading to ongoing transmission. While there is a push for active case finding (ACF) to improve early detection and treatment of TB, there is extremely limited evidence about the relative cost-effectiveness of different ACF implementation models. Cambodia presents a unique opportunity for addressing this gap in evidence as ACF has been implemented using different models, but no comparisons have been conducted. The objective of our study is to contribute to knowledge and methodology on comparing cost-effectiveness of alternative ACF implementation models from the health service perspective, using programmatic data, in order to inform national policy and practice.

METHODS

We retrospectively compared three distinct ACF implementation models - door to door symptom screening in urban slums, checking contacts of TB patients, and door to door symptom screening focusing on rural populations aged above 55 - in terms of the number of new bacteriologically-positive pulmonary TB cases diagnosed and the cost of implementation assuming activities are conducted by the national TB program of Cambodia. We calculated the cost per additional case detected using the alternative ACF models.

RESULTS

Our analysis, which is the first of its kind for TB, revealed that the ACF model based on door to door screening in poor urban areas of Phnom Penh was the most cost-effective (249 USD per case detected, 737 cases diagnosed), followed by the model based on testing contacts of TB patients (308 USD per case detected, 807 cases diagnosed), and symptomatic screening of older rural populations (316 USD per case detected, 397 cases diagnosed).

CONCLUSIONS

Our study provides new evidence on the relative effectiveness and economics of three implementation models for enhanced TB case finding, in line with calls for data from 'routine conditions' to be included in disease control program strategic planning. Such cost-effectiveness comparisons are essential to inform resource allocation decisions of national policy makers in resource constraint settings. We applied a novel, pragmatic methodological approach, which was designed to provide results that are directly relevant to policy makers, costing the interventions from Cambodia's national TB program's perspective and using case finding data from implementation activities, rather than experimental settings.

Extending 'Contact Tracing' into the Community within a 50-Metre Radius of an Index Tuberculosis Patient Using Xpert MTB/RIF in Urban, Pakistan: Did It Increase Case Detection?

Background

Currently, only 62% of incident tuberculosis (TB) cases are reported to the national programme in Pakistan. Several innovative interventions are being recommended to detect the remaining ‘missed’ TB cases. One such intervention involved expanding contact investigation to the community using the Xpert MTB/RIF test.

Methods

This was a before and after intervention study involving retrospective record review. Passive case finding and household contact investigation was routinely done in the pre-intervention period July 2011-June 2013. Four districts with a high concentration of slums were selected as intervention areas; Lahore, Rawalpindi, Faisalabad and Islamabad. Here, in the intervention period, July 2013-June 2015, contact investigation beyond household was conducted: all people staying within a radius of 50 metres (using Geographical Information System) from the household of smear positive TB patients were screened for tuberculosis. Those with presumptive TB were investigated using smear microscopy and the Xpert MTB/RIF test was performed on smear negative patients. All the diagnosed TB patients were linked to TB treatment and care.

Results

A total of 783043 contacts were screened for tuberculosis: 23741(3.0%) presumptive TB patients were identified of whom, 4710 (19.8%) all forms and 4084(17.2%) bacteriologically confirmed TB patients were detected. The contribution of Xpert MTB/RIF to bacteriologically confirmed TB patients was 7.6%. The yield among investigated presumptive child TB patients was 5.1%. The overall yield of all forms TB patients among investigated was 22.3% among household and 19.1% in close community. The intervention contributed an increase of case detection of bacteriologically confirmed tuberculosis by 6.8% and all forms TB patients by 7.9%.

Conclusion

Community contact investigation beyond household not only detected additional TB patients but also increased TB case detection. However, further long term assessments and cost-effectiveness studies are required before national scale-up.

An Evaluation of Passive and Active Approaches to Improve Tuberculosis Notifications in Afghanistan

Background

In Afghanistan, improving TB case detection remains challenging. In 2014, only half of the estimated incident TB cases were notified, and notifications have decreased since peaking in 2007. Active case finding has been increasingly considered to improve TB case notifications. While access to health services has improved in Afghanistan, it remains poor and many people seeking health services won’t receive proper care.

Methods

From October 2011 through December 2012 we conducted three separate case finding strategies in six provinces of Afghanistan and measured impact on TB case notification. Systematically screening cough among attendees at 47 health facilities, active household contact investigation of smear-positive index TB patients, and active screening at 15 camps for internally displaced people were conducted. We collected both intervention yield and official quarterly notification data. Additional TB notifications were calculated by comparing numbers of cases notified during the intervention with those notified before the intervention, then adjusting for secular trends in notification.

Results

We screened 2,022,127 people for TB symptoms during the intervention, tested 59,838 with smear microscopy and detected 5,046 people with smear-positive TB. Most cases (81.7%, 4,125) were identified in health facilities while nearly 20% were found through active case finding. A 56% increase in smear-positive TB notifications was observed between the baseline and intervention periods among the 47 health facilities, where cases detected by all three strategies were notified.

Discussion

While most people with TB are likely to be identified through health facility screening, there are many people who remain without a proper diagnosis if outreach is not attempted. This is especially true in places like Afghanistan where access to general services is poor. Targeted active case finding can improve the number of people who are detected and treated for TB and can push towards the targets of the Stop TB Global Plan and End TB Strategy.

Active Tuberculosis Case Finding in Port-au-Prince, Haiti: Experiences, Results, and Implications for Tuberculosis Control Programs

Background. Haiti has the highest tuberculosis (TB) prevalence in the Americas with 254 cases per 100,000 persons. Case detection relies on passive detection and TB services in many regions suffer from poor diagnostic and clinical resources. Methods. Mache Chache ("Go and Seek") was a TB REACH Wave 3 funded TB case finding project in Port-au-Prince between July 2013 and September 2014, targeting four intervention areas with insufficient TB diagnostic performance. Results. Based on a verbal symptom screen emphasizing the presence of cough, the project identified 11,150 (11.75%) of all screened persons as TB subjects and 2.67% as smear-positive (SS+) TB cases. Enhanced case finding and strengthening of laboratory services led to a 59% increase in bacteriologically confirmed cases in the evaluation population. In addition, smear grades dropped significantly, suggesting earlier case detection. Xpert® MTB/RIF was successfully introduced and improved TB diagnosis in HIV-infected, smear-negative clinic patients, but not in HIV-negative, smear-negative TB suspects in the community. However, the number needed to screen for one additional SS+ case varied widely between clinic and community screening activities. Conclusion. Enhanced and active TB case finding in Haiti can improve TB diagnosis and care. However, screening algorithms have to be tailored to individual settings, necessitating long-term commitment.

A tuberculosis nationwide prevalence survey in Gambia, 2012

Objective

To estimate the population prevalence of active pulmonary tuberculosis in Gambia.

Methods

Between December 2011 and January 2013, people aged ≥ 15 years participating in a nationwide, multistage cluster survey were screened for active pulmonary tuberculosis with chest radiography and for tuberculosis symptoms. For diagnostic confirmation, sputum samples were collected from those whose screening were positive and subjected to fluorescence microscopy and liquid tuberculosis cultures. Multiple imputation and inverse probability weighting were used to estimate tuberculosis prevalence.

Findings

Of 100 678 people enumerated, 55 832 were eligible to participate and 43 100 (77.2%) of those participated. A majority of participants (42 942; 99.6%) were successfully screened for symptoms and by chest X-ray. Only 5948 (13.8%) were eligible for sputum examination, yielding 43 bacteriologically confirmed, 28 definite smear-positive and six probable smear-positive tuberculosis cases. Chest X-ray identified more tuberculosis cases (58/69) than did symptoms alone (43/71). The estimated prevalence of smear-positive and bacteriologically confirmed pulmonary tuberculosis were 90 (95% confidence interval, CI: 53–127) and 212 (95% CI: 152–272) per 100 000 population, respectively. Tuberculosis prevalence was higher in males (333; 95% CI: 233–433) and in the 35–54 year age group (355; 95% CI: 219–490).

Conclusion

The burden of tuberculosis remains high in Gambia but lower than earlier estimates of 490 per 100 000 population in 2010. Less than half of all cases would have been identified based on smear microscopy results alone. Successful control efforts will require interventions targeting men, increased access to radiography and more accurate, rapid diagnostic tests.

High uptake of systematic HIV counseling and testing and TB symptom screening at a primary care clinic in South Africa

Background

Timely diagnosis and treatment of tuberculosis (TB) and HIV is important to reduce morbidity and mortality, and break the cycle of ongoing transmission.

Methods

We performed an implementation research study to develop a model for systematic TB symptom screening and HIV counseling and testing (HCT) for all adult clients at a primary care clinic and prospectively evaluate the 6-month coverage and yield, and 18-month sustainability at a primary care clinic in Johannesburg, South Africa.

Results

During the first 6 months, 26,515 visits occurred among 12,078 adults. The proportion of adults aware of their HIV status was 43.7% at the start of the first visit, increased to 84.6% at the end of the first visit, and to 90% at end of any visit during the first 6 months. During these 6 months, 1042 clients were newly diagnosed with HIV. HIV prevalence was 22.9% among those newly tested, and 58.9% among all adult clinic clients. High coverage of systematic HCT was sustained across all 18 months. Coverage of systematic HIV-stratified TB symptom screening during first 6-months was also high (89.6%) but only 35.0% of those symptomatic were screened by sputum. During these 6-months, 90 clients had a positive Xpert MTB/RIF assay, corresponding to a TB prevalence of 0.4% among all 23,534 clients TB symptom-screened and 2.8% among the 3,284 clients with a positive TB symptom screen. The initial high coverage of TB symptom screening was not sustained, with coverage of TB symptom screening dropping after the first six months to 70% and assessment by sputum dropping to 15%.

Conclusion

Routine, systematic HCT and HIV-stratified TB symptom screening is feasible at primary care level. Systematic HCT doubled the proportion of clients with known HIV status. While HCT was sustainable, coverage of systematic TB screening dropped significantly after the first 6 months of implementation.

Diagnostic accuracy of computer-aided detection of pulmonary tuberculosis in chest radiographs: a validation study from sub-Saharan Africa

Background

Chest radiography to diagnose and screen for pulmonary tuberculosis has limitations, especially due to inter-reader variability. Automating the interpretation has the potential to overcome this drawback and to deliver objective and reproducible results. The CAD4TB software is a computer-aided detection system that has shown promising preliminary findings. Evaluation studies in different settings are needed to assess diagnostic accuracy and practicability of use.

Methods

CAD4TB was evaluated on chest radiographs of patients with symptoms suggestive of pulmonary tuberculosis enrolled in two cohort studies in Tanzania. All patients were characterized by sputum smear microscopy and culture including subsequent antigen or molecular confirmation of Mycobacterium tuberculosis (M.tb) to determine the reference standard. Chest radiographs were read by the software and two human readers, one expert reader and one clinical officer. The sensitivity and specificity of CAD4TB was depicted using receiver operating characteristic (ROC) curves, the area under the curve calculated and the performance of the software compared to the results of human readers.

Results

Of 861 study participants, 194 (23%) were culture-positive for M.tb. The area under the ROC curve of CAD4TB for the detection of culture-positive pulmonary tuberculosis was 0.84 (95% CI 0.80–0.88). CAD4TB was significantly more accurate for the discrimination of smear-positive cases against non TB patients than for smear-negative cases (p-value<0.01). It differentiated better between TB cases and non TB patients among HIV-negative compared to HIV-positive individuals (p<0.01). CAD4TB significantly outperformed the clinical officer, but did not reach the accuracy of the expert reader (p = 0.02), for a tuberculosis specific reading threshold.

Conclusion

CAD4TB accurately distinguished between the chest radiographs of culture-positive TB cases and controls. Further studies on cost-effectiveness, operational and ethical aspects should determine its place in diagnostic and screening algorithms.

A pragmatic approach to measuring, monitoring and evaluating interventions for improved tuberculosis case detection

The inability to detect all individuals with active tuberculosis has led to a growing interest in new approaches to improve case detection. Policy makers and program staff face important challenges measuring effectiveness of newly introduced interventions and reviewing feasibility of scaling-up successful approaches. While robust research will continue to be needed to document impact and influence policy, it may not always be feasible for all interventions and programmatic evidence is also critical to understand what can be expected in routine settings. The effects of interventions on early and improved tuberculosis detection can be documented through well-designed program evaluations. We present a pragmatic framework for evaluating and measuring the effect of improved case detection strategies using systematically collected intervention data in combination with routine tuberculosis notification data applying historical and contemporary controls. Standardized process evaluation and systematic documentation of program implementation design, cost and context will contribute to explaining observed levels of success and may help to identify conditions needed for success. Findings can then guide decisions on scale-up and replication in different target populations and settings.

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.