Introduction

Background

Tuberculosis (TB) is a widespread and chronic infectious disease that is globally spread and is caused by the pathogen Mycobacterium tuberculosis [1]. In accordance with estimations, approximately 40 million individuals are afflicted with TB in the year 2022, with 3.5 million of those being children [2]. Low-and middle-income countries (LMICs) bear a disproportionate burden of high morbidity and mortality associated with TB [3]. The Southeast Asia and Western Pacific regions accounted for the highest number of TB cases, followed by the African region. In these regions, the morbidity rates can reach as high as 95%, with mortality rates up to 98% [4]. Tuberculosis case-finding mechanism is mostly passive in low- and middle-income countries due to the presence of potential obstacles. This system relies on individuals reporting for diagnosis rather than active outreach programs [5, 6].

Active case detection is a novel methodology for tuberculosis screening that exhibits significant potential to augment the timely identification of cases in underserved communities [7]. This approach is largely directed towards demographic groups that are considered high-risk, comprising individuals who are homeless, incarcerated, receiving care in nursing homes, and residing in economically disadvantaged regions [8]. Unlike passive case-finding, ACF involves actively searching for TB in individuals who would not seek care spontaneously. The strategy aimed to eradicate tuberculosis, as acknowledged by the World Health Organization, recognizes ACF as a vital methodology for the identification of tuberculosis cases that are currently being disregarded by healthcare facilities [9].

In nations like the United States, Northern America, Canada, and the European Union, where the occurrence of tuberculosis is low, there are policies in place that aim to proactively identify incidences of the disease. Conversely, a majority of lower and middle-income countries with substantial TB burdens depend on passive case detection. This reliance on passive case detection has contributed to the current failure to prevent transmission at the necessary level [10, 11]. Despite the potential that ACF holds for amplifying the early detection of cases among marginalized populations, there exist substantial barriers to the adoption of ACF strategies in low and middle-income countries. These barriers may include inadequate capacity-building for healthcare workers, limited accessibility to healthcare facilities, and insufficient community involvement [12]. Moreover, while some studies have investigated ACF interventions, there is a lack of summarized results about the barriers and facilitators of ACF.

This systematic review is necessary to provide evidence-based recommendations for ACF interventions that can increase the detection of TB cases in low and middle-income countries. The findings of this study will have significant implications for policymakers, healthcare professionals, and researchers, enabling them to plan and design effective TB ACF interventions that improve TB control in these countries. In addition, this investigation will contribute to the global efforts aimed at achieving the WHO End TB strategy and the sustainable development goals.

The present review highlights the significance of addressing the challenge of active case finding for tuberculosis (TB-ACF) in low- and middle-income countries (LMICs) through thorough investigation and evidence-based proposals as evidenced by the existing literature.

While it is acknowledged that TB remains a major public health challenge worldwide, with LMICs bearing a disproportionate burden of high morbidity and mortality, the current passive case-finding mechanism in these countries is insufficient to effectively identify and treat cases [10, 12].

The purpose of this study is to investigate the barriers and facilitators of TB-ACF in LMICs, providing insights and recommendations for future ACF policy development. By conducting a systematic review of existing studies, this research aims to fill the gap in summarized results and generate evidence-based findings that can guide policymakers, healthcare professionals, and researchers in planning and designing effective ACF interventions. The implications of this study are significant, as it has the potential to improve TB control in LMICs by enhancing case detection rates. The findings will inform the development of targeted interventions and strategies that overcome the identified barriers and leverage the facilitators of TB-ACF. Policymakers can use these recommendations to implement evidence-based policies that support proactive case identification, ultimately reducing transmission rates and improving patient outcomes.

Furthermore, this investigation aligns with global efforts to achieve the World Health Organization’s End TB strategy and the sustainable development goals. By focusing on TB-ACF in LMICs, where the burden of the disease is particularly high, this research contributes to the broader objective of eliminating TB as a global public health threat.

In summary, this systematic review is essential to justify the need for investigating TB-ACF in LMICs. By identifying barriers, facilitators, and providing evidence-based recommendations, this study aims to improve ACF policy development, enhance case detection rates, and contribute to global efforts in combating TB.

Objective

To identify the facilitators and barriers of tuberculosis to ACF in low- and middle-income countries (LMICS).

Review questions

  • What are the facilitating factors for TB -ACF in low and middle-income countries?

  • What are the barriers to active TB case detection in low- and middle-income countries?

  • What are the healthcare system and non-healthcare system -related barriers to TB-ACF in LMICS?

Methodology

Synthesis methods

Enhancing transparency in reporting the synthesis of qualitative research (ENTREQ) statement was used for strengthening the protocol for the systematic review [13] (Additional file 2).The items have been meticulously collated and systematically classified into five distinct categories, namely: introduction, methods and methodology, literature search and selection, appraisal, and synthesis of findings.

Inclusion criteria

The current systematic review included studies with any qualitative study design, which can be conducted using either qualitative studies or mixed methods. Criterion (1): research question the paper is based on a clearly defined research question, which is clearly discussed and referenced throughout the paper. Criteria 2: Internal validity: the design of the study is suitable for the posed research inquiry and has unambiguously enunciated the study objectives. Selection bias has been minimized; confounding factors have been identified and/or controlled; explanatory variables are based on sound scientific principles; and outcome measures are complete and reliable. Criteria 3: Clarity of Results: Well-described and appropriate analytical methods were used. The precision of association is given or calculable and is meaningful. Criteria 4: External validity: The source population is well described, and the eligible population represents the source population. Selected participants represent an eligible population, and the results are consistent with results from other studies. The study results are generalizable to the source population. Any study that used qualitative methods of data collection (individual interviews, focus group discussions, and observation) and data analysis (thematic analysis) was included. The articles examining barriers and/or facilitators have been included. Healthcare providers involved in active case finding, community health workers (HCWs) and volunteer health managers, peer volunteers, policymakers, suspected TB patients, activists, academics, and other stakeholders encountered in the studies on ACF were included in the review. All studies conducted in WHO Member States grouped into low- and middle-income countries were included. Articles on barriers and promoters examining factors related to active TB case finding at the health system, individual, and community levels in low- and middle-income countries were included.

Exclusion criteria

Study types like clinical trials, case-control, and cohort study types were excluded, and studies with comments from quantitative surveys, editorials, and opinion pieces were also excluded. Studies conducted within groups in high-income countries were also excluded. Studies not reported in English were excluded.

Search strategy and data sources

Electronic databases, including PubMed, Google Scholar, Scopus, HINARI, and other sources, were searched using Endnote Manager for sorting and filtering the articles for review. In addition, Microsoft Excel was used to facilitate the screening of the imported articles. The search strategy incorporated the key terms of the review question and utilized Boolean search operators. The key terms were: facilitators, enablers, barriers, challenges, “active case finding” “systematic screening” “community-based case finding” OR “community-based case detection” “tuberculosis,“ and “low and middle-income countries”. The search results were presented in the form of a flow diagram, as recommended by the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) (Fig. 1). A total of 228 articles were browsed through these electronic databases and other methods. A total of 9 articles were removed for duplicates, being marked as ineligible, or for other reasons. A total of 104 articles were excluded through title and abstract screening. One hundred fifteen (115) article reports were sought for retrieval, and 29 were evaluated for eligibility. Finally, only 23 full-text articles were deemed suitable for qualitative and quantitative synthesis.

Fig. 1
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PRISMA flow diagram to investigate the facilitators and barriers of TB ACF in LMICs.

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Quality assessment

The included relevant studies were critically assessed by two independent authors (AA and MD). The JBI Critical Appraisal Tool was used to assess the quality of the qualitative studies included in this review [14] (see additional file 1). In addition, we graded the final synthesized qualitative findings according to the CERQual approach to rate the level of confidence and certainty of the findings [15].

Data extraction and analysis

In brief, the entirety of the retrieved publications in various databases underwent initial screening. The abstracts of the aforementioned publications were scrutinized by two independent reviewers (MD and OA) acting individually. Instances, where judgments conflicted, were subsequently resolved by the authors who made the initial screening decisions. The screening of full texts was executed in a comparably to that of abstracts. Then they were shared online with another reviewer (AA). The reviewers used a customized JBI data abstraction format. As members are located in different countries, online Zoom meetings were scheduled once a week for this process. For urgent purposes, phone calls, emails, and internet account group SMS were used as means of contact. These communications should discuss solutions to unclear points regarding the eligibility criteria and other confusing issues. For example, there was a disagreement between two reviewers (AA and MD) regarding the classification of barriers and promoters in low- and middle-income countries. This was resolved during one of our online engagements that all group members attended. We developed a standardized form to identify included studies and settings (publication year, published journals, study design, interventions, and country) and participant characteristics (type of participants, e.g., health workers, number of participants, etc.) and the primary outcome measures (key barriers and facilitators) in LMICs.

After conducting data extraction for each paper, the studies were categorically grouped according to the outcomes of interest. Subsequently, narrative summaries for each outcome were presented and analyzed. The data was then analyzed and summarized using both pictorial and tabular representations. Firstly, the findings were classified into two categories, namely, barriers related to low- and middle-income countries. Secondly, the theme was summarized into the main findings. Subsequently, the quality assessment tool was applied. Concurrently, the findings, especially the barriers, were categorized into theme 1 as healthcare system-related and non-healthcare system-related barriers. Finally, patient-related, health-related, resource-related, and implementation-related factors were considered. Ultimately, the quality assessment tool CERQual was applied to the findings. Six out of the total eight preliminary findings have been chosen as the “key findings” to undergo further analysis through the Confidence in the Evidence from Reviews of Qualitative Research (CERQual) tool. The selection process was based on a consensus between three authors (AG, AA), where the strength of evidence, number of supporting reviews, level of variability in review findings, and significance of the findings as indicated in the included reviews were taken into consideration.

Results

Review description

A total of 23 studies from 2013 to 2020 were included in the final review. These studies were organized according to the title of the article, study location or country, methods, sample characteristics, and author(s) with the year of publication (see Table 1). The results were presented based on the major themes of barriers and facilitators that emerged from the analysis and synthesis. The barriers are further presented as healthcare system and non-healthcare system related barriers. Of the included studies, it was noted that two of the articles in question did not explicitly mention the ethical considerations that were taken into account when formulating their research protocols.

Table 1 Summary of study characteristics (n = 23)
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Healthcare system and governmental related barriers

The challenges in implementing ACF in healthcare have been inadequate healthcare worker training and staff shortages. The main gaps in tuberculosis control have been recognized as the limited availability of healthcare facilities and insufficient community involvement [12, 38]. Funding subsistence for tuberculosis care is a long-term challenge in many countries. To alleviate this financial burden, specific measures are needed at different levels, including linking tuberculosis to the overall social protection system [26, 39]. Resource constraints in LMICs limit TB contact investigation despite its benefits outweighing its cost and its increased efficiency when compared with intensified case finding (see Tables 2 and 3). Inadequate laboratory infrastructure for maintaining functional Xpert equipment further challenges implementation and scale-up [40]. Generally, shortages of healthcare providers, inadequate basic infrastructure, and inadequate diagnostic equipment and supplies were identified as barriers to TB case finding [41]. Also included was limited access to TB diagnostic services, which can be absent or characterized by delays in the diagnostic process.

Access and health service delays, longer distances, transportation costs, poor quality of services, understaffing, poor motivation, outdated protocols, limited laboratory supplies, limited screening among high-risk groups, and poor data quality and feedback systems were the major constraints to TB diagnosis and implementation of services in Liberia [42]. Commonly noted barriers in Uganda included insufficient time and space in clinics for counseling and mistrust of health-center staff among index patients and contacts [43]. Logistics and infrastructure, waiting time and institutional readiness, referral, feedback, human resources, charges for using some laboratories, workloads, and distance to TB facilities were barriers to TB contact tracing and investigation in Ethiopia [44].

Table 2 Key barriers and facilitators of active TB case findings in low-income countries identified from the included studies (n = 11)
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Table 3 Key barriers and facilitators of active TB case findings in middle income countries identified from the included studies (n = 12)
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Healthcare system-related and non- healthcare system-related barriers

The identification of active tuberculosis is impeded by two main categories of obstacles, namely health system-related and non-health system-related barriers, as illustrated in Table 4; Fig. 2. The studies analyzed in this research revealed several health system-related barriers, among which a dearth of diagnostic resources (including equipment, reagents, and tests), as well as inadequate TB awareness, were the most frequently observed ones. Conversely, barriers not associated with the healthcare system encompassed stigmatization, transportation costs, insufficient education, limited awareness concerning diagnostic testing, and the presence of a language barrier.

Limited understanding and awareness regarding the identification of signs and symptoms, as well as misconceptions surrounding tuberculosis, have proven to be the primary contributing factors to the delay in patients accessing tuberculosis services [44]. Nevertheless, the familiarity and knowledge of the community demonstrated by village health volunteers have been crucial in facilitating the initial access to active case-finding participants. However, at times, this familiarity has negatively impacted their perceived legitimacy among community members who are aware of their lack of medical training. To gain respect among their peers in the community, village health volunteers recognize the importance of affiliating with tuberculosis workers and other trained healthcare providers [45].

According to Marangu et al.[29], the key barriers to CI were the failure of HCWs to educate and invite TB patients to bring close contacts for TB screening, sub-optimal processes and flow of TB patients, HCW and community TB-related stigma [46]. In another study, knowledge, commitment and motivation, and stigma and discrimination for household contact-tracing of index TB cases were also identified [47]. One practical consideration for the implementation of targeted ACF activities was convincing individuals to undergo screening for a stigmatized disease, especially if the screening requires time and effort on the part of the individuals[24]. Seeking private health care and self-medication before TB diagnosis, lack of perceived risk, threat, susceptibility, and stigma derived qualitatively further explained the quantitative findings [41]. The different attitude of the community due to stigma, lack of awareness about TB, illiteracy and inability to convince patients for sputum tests were challenges to conduct ACF [42]. High travel costs for LHWs and contacts were also noted as barriers to TB contact investigation [43].

Table 4 Healthcare system and non- healthcare system-related barriers to tuberculosis active case findings in LMICS (n = 21)
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Fig. 2
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The major barberries classified under healthcare and non-healthcare systems in LMICS

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Facilitators

The most important facilitators identified were the personalized and enabling services provided by LHWs. The study identified education, persuasion, enablement, modeling of health-positive behaviors, incentivization, and restructuring of the service environment as relevant intervention functions with potentials to alleviate barriers to and enhance facilitators of TB contact investigations[26]. Implementers’ motivation and incentives fostered active case-finding policy implementation[48]. Public health providers were motivated by the increased early case detection and expedited sequence from screening to treatment. TB workers were motivated by the increased awareness, improved health-seeking behaviors among TB patients and strengthened competence of village health volunteers in target communities [49].

To address the challenge of TB “missing cases”, policies, effective strategies, and implementation of active case interventions for TB key populations are highly essential globally [17]. By bringing TB services closer to the community, participants reported that ACF had removed barriers to access and cost. This was particularly appreciated by the elderly and severely ill, whose physical conditions prevented them from traveling to the health centers for screening and treatment [50]. Ensuring and outlining good health outcomes, and limiting TB transmission within hard-to-reach groups, can prove challenging. The reason is that the hard-to-reach groups may experience difficulties in accessing care, and if they do access it, they may experience difficulties remaining in it[51].

Approaches such as improving TB diagnostic tools and algorithms, and engaging all care providers are suggested to find missing TB patients[52]. The involvement of HCWs in the general activities of counseling patients, and issuing of identity cards to them for ease of recognition, was recommended to foster ACF [53]. To maintain benefits from different approaches, there is a need to distinguish between CHWs that are trained and remunerated to be a part of an existing health system and those who, with little training, take on roles and are motivated by a range of contextual factors. Governments and planners can benefit from understanding the program that can best be supported in their communities, thereby maximizing motivation and effectiveness[54].

Assessment of confidence in the evidence of the review findings

Two of the reviewer authors (MD and AG) applied the confidence of evidence review quality (CERQual) approach to assess the confidence in the findings of the review independently. Then, the evidence review quality approach assesses confidence in the review findings and is conducted based on four components namely; the methodological limitations of included studies, the relevance of the included studies to the review question, the coherence of the review findings and the adequacy of data contributing to the review findings [55] as shown Fig. 3. Every issue or phenomenon that was relevant to the four components was noted in the review results and taken into account when determining the overall CERQual assessment as high, moderate, low, or extremely low as depicted in Table 5.

The barriers that were identified during our review have been consolidated into eight overarching themes. These themes were derived from general concepts and through consensus among the review authors, as detailed in Table 6. In addition, our summary of qualitative findings included a CERQual assessment and a written justification, as outlined previously. It is important to note that the findings presented in our review are contingent upon various factors, such as the review question, the synthesis techniques employed, the intended application or target of the synthesis, and the depth of the data provided. These factors collectively influence the conclusions that we have drawn from our analysis [56].

Table 5 Summary of CERQual Confidence Rating on the main findings
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Fig. 3
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The components of CERQual

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Table 6 Confidence of Evidence Review quality (CERQual) summary of review findings, appraisal, and synthesis of qualitative research evidence on the barriers and facilitators to tuberculosis active case findings in low- and middle-income countries
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Discussion

In this qualitative systematic review, we identified 23 studies (12 from middle-income countries and 11 from low-income countries), of which 19 reported qualitative data methods on barriers and facilitators of TB case finding to earlier detection in LMICs. All studies of these LMICs identified hard-to-reach communities as the main carriers of this disease. Advanced and effective TB programs are needed given the disease’s contagiousness, airborne transmission and rising TB incidence in some countries. In terms of the study design, five of the investigations delineated mixed-method barriers and facilitators [23, 31, 33, 36].

In general, the overall evidence supporting the factors influencing tuberculosis ACF in low- and middle-income countries were high at present, despite several interventions and varying types of tools adopted in different patient populations in the LMICs. This study reported a slightly positive influence associated with facilitators of TB contact investigation and ACF. There were a few overlapping explanations for the factors influencing TB ACF [16, 22,23,24, 26, 27, 32] and for positive psycho-social interventions used as the facilitators of ACF. In tuberculosis ACF, systematic identification and screening of people with presumptive TB symptoms, in a pre-determined target group, using tests, examinations, or other procedures that can be applied rapidly [57]. Interventions relating more to the psycho-social factors in persons, who were asymptomatic for TB, such as group-based psychotherapy, are important to boost and give confidence to stigmatized persons. This way could improve interpersonal and self-esteem as well as public health value by influencing positively psycho-social factors like mood, thereby affecting interpersonal barriers.

Inadequate resources, limited access to diagnostic services, inadequate diagnostic equipment and supplies were the most important factors influencing active case findings both low and middle-income countries [17, 20, 25, 36], while TB communication strategy and language were the key barriers for tuberculosis ACF [16, 18]. Peer-led, patient-centered approaches and community involvement increased the active finding of TB cases [23, 28].

This study suggested that TB case identification may be improved if the community could easily access health facilities with TB diagnostic services. Similarly, studies show that case notification increase in areas where community members have better access to facilities with TB diagnostic services [20, 58]. In most low income countries, health extension workers are intentionally placed at the community level to reinforce the accessibility of the rural population to different health services, including TB care. Still, health extension workers lack, so to alleviate the lack of transportation facilities to reach TB services and increase the ACF strategies the number of health extension workers and community-based identification methods should be scaled up in rural and remote areas.

The use of an active case-finding approach, which includes conducting household symptom screening through door-to-door community visits coupled with the integration of laboratory testing, has resulted in improved detection of tuberculosis cases in rural areas. This finding is supported by reference [59]. Moreover, active case finding through community outreach improved the speed of TB case finding, which indicated a possibility to reduce delays in TB diagnosis [60]. This strategy could help in solving problems related to unmet health needs in general, and undiagnosed TB cases in particular, for the rural population. The current review has ascertained that stigma is frequently encountered and functions as an impediment to obtaining care for those with ACF-TB; this may plausibly be attributed to the lack of health advocacy and awareness initiatives. Stigmatization and discrimination pose significant risks to individuals undergoing TB screening or diagnosed with TB, potentially undermining the success of the screening process.

The needs of vulnerable people must be served by increasing access to healthcare services while simultaneously minimizing the direct and indirect costs of seeking medical care. This can be achieved by strengthening primary health-care services, providing additional outreach services that cater to these populations, and implementing social protection schemes where necessary. In order to ensure that individuals with prevalent active TB cases seek care at facilities capable of diagnosing and treating TB, community engagement and demand in communities at a higher risk of TB must be increased. The implementation and adaptation of bidirectional screening, as demonstrated by this investigation, provides valuable proof to enhance the outcomes of TB-active case detection.

The findings of this qualitative systematic review have significant implications for policy modification and development in the context of tuberculosis active case finding (TB-ACF) in low- and middle-income countries (LMICs). The identified studies highlight various barriers and facilitators that influence TB case detection and earlier diagnosis in LMICs [21].

One key implication is the need for advanced and effective TB-ACF programs, considering the contagiousness and airborne transmission of the disease, as well as the rising TB incidence in certain countries. The study emphasizes the importance of targeted interventions and tools to reach hard-to-reach communities, which have been identified as the main carriers of TB [22].

The study also highlights the value of psychosocial interventions, such as group-based psychotherapy, to help stigmatized people overcome interpersonal barriers, increase their confidence, and boost their self-esteem. By influencing psychosocial aspects such as mood and promoting improved access to diagnostic services, these interventions can have a positive impact on TB-ACF outcomes [23]. The review also highlights specific barriers that need to be addressed, including failure of health workers to educate and invite TB patients to bring their close contacts to be screened, suboptimal processes and patient flows, TB-related stigma and knowledge gaps among HCWs, discrimination in contact tracing in the Budget, insufficient resources and limited access to diagnostic services, and communication barriers [26].

In order to surmount the barriers impeding TB-ACF and to amplify its facilitators, the present study suggests a range of measures. Firstly, enhancing community access to health facilities with TB diagnostic services is recommended. Secondly, there is a need to scale up the number of health extension workers in rural and remote areas. Furthermore, active case finding through community outreach and door-to-door visitation should be implemented. Lastly, addressing stigma through health advocacy and awareness programs is crucial. Thirdly, it is imperative to address these challenges by means of providing adequate training to healthcare workers [61].

Additionally, this review stresses the significance of improving access to care, reducing costs associated with seeking care, strengthening primary health-care services, providing outreach services for vulnerable populations, and implementing social protection schemes where necessary. These findings are in line with other studies conducted in LMICs, which have also adopted multiple interventions and strategies to enhance TB-ACF. However, more comprehensive and coordinated efforts are required to address the identified barriers and utilize the facilitators of TB-ACF effectively.

The strength and limitation of the study

Active case finding represents the most prominent approach in controlling and preventing tuberculosis. Given its significance, this finding offers a critical source of information in the global efforts to eradicate TB, as it constitutes the first summary of active case finding. However, it should be noted that these findings cannot be universally applied across all populations and diseases. The strength of this systematic review is rooted in the use of different guidance and qualitative check tools, such as PRISMA, CEQual, BJI, and ENTREQ, thus underscoring its status as an evidence-based study. One of the limitations of this review is its small sample size, which only includes 23 studies, thereby potentially reducing its generalizability. Another limitation pertains to the analysis methods employed for the qualitative data, as the review relied solely on narrative summaries presented in tables and diagrams. The other basic limitation of this manuscript is lack of PROSPERO Registration number.

Conclusion

This qualitative systematic review examines that stigma is the top patient- and community-related barrier, followed by health-system-related barriers such as lack of resources, including lack of diagnostic equipment, reagents, and consumables for the detection of cases with active TB. In this review, supervision, health worker training, leadership, integration into health systems, and long-term funding are key to the sustainability of tuberculosis-ACF. Financial support for staff time and program costs associated with expanding patient enrollments were seen as important factors in maintaining public sector commitment. In addition, government leadership, the existence of specific policies, the knowledge, clinical skills, and capacity building of frontline health workers are also key enablers for ACF in LMICs. The risks of stigmatization should be carefully assessed prior to initiating screening of the patients.

In conclusion, this review provides valuable evidence to support the modification and development of policies related to TB-ACF in LMICs. By addressing the identified barriers, promoting community engagement, and implementing bidirectional screening, policymakers can enhance TB case detection, reduce delays in diagnosis, and improve overall outcomes of TB-ACF programs.