Community-based Active Case Finding Research Articles

Sputum and tongue swab molecular testing for the in-home diagnosis of tuberculosis in unselected household contacts: a cost and cost-effectiveness analysis.

Delayed and missed diagnosis are a persistent barrier to tuberculosis control, partly driven by limitations associated with sputum collection and an unmet need for decentralized testing. Household contact investigation with point-of-care testing of non-invasive specimens like tongue swabs are hitherto undescribed and may be a cost-effective solution to enable community-based active case finding. In-home, molecular point-of-care testing was conducted using sputum and tongue specimens collected from all household contacts of confirmed tuberculosis cases. A health economic assessment was executed to estimate and compare the cost and cost-effectiveness of different in-home, point-of-care testing strategies. Incremental cost effectiveness ratios of strategies utilizing different combination testing algorithms using sputum and/or tongue swab specimens were compared. The total implementation cost of delivering the standard of care for a 2-year period was $84 962. Strategies integrating in-home point-of-care testing ranged between $87 844 - $93 969. The cost-per-test for in-home, POC testing of sputum was the highest at $20·08 per test. Two strategies, Point-of-Care Sputum Testing and Point-of-Care Combined Sputum and Individual Tongue Swab Testing were the most cost-effective with ICERs of $543·74 and $547·29 respectively, both below a $2,760 willingness-to-pay threshold. An in-home, point-of-care molecular testing strategy utilizing combination testing of tongue swabs and sputum specimens would incur an additional 10.6% program cost, compared to SOC, over a 2-year period. The increased sample yield from tongue swabs combined with immediate result notification following, in-home POC testing would increase the number of new TB cases detected and linked to care by more than 800%. Evidence before this study: We searched PubMed for original research published between January 1, 1950 and June 30, 2024 that evaluated the cost-effectiveness of in-home POC molecular testing, as part of HCI strategies for tuberculosis. PubMed search terms used included ["household contact investigation" OR "household contact tracing"] AND "tuberculosis" AND "cost-effectiveness". The search revealed 8 studies, of which one was removed as HCIs were leveraged for the provision of short course preventative therapy and not tuberculosis testing. None of the studies were conducted in South Africa. All seven remaining studies relied on a hub-and-spoke model of sputum collection and transportation with sputum tested at a centralized laboratory facility. Although active case finding strategies like HCIs are endorsed by the WHO to improve early case detection and treatment initiation, limited research has been done to assess its cost-effectiveness in low- and middle-income countries.Added value of this study: To our knowledge, this is the first example of in-home molecular point-of-care (POC) testing as part of HCI. The use of primary data to estimate and compare the incremental cost effectiveness of different combination, in-home testing strategies utilizing alternative sample types equips policy makers with a selection of strategy options to choose from. The tradeoff between sample types with high collection yield and those with increased accuracy becomes evident in the economic analysis, highlighting the need to consider both yield and accuracy in effective clinical decision making and use-case development. The success of in-home, POC tongue swab testing of all contacts, irrespective of symptom presentation shows great promise for universal testing programs.Implications of all available evidence: Results from our economic modeling provide evidence in support for the integration of in-home, POC tuberculosis (TB) testing during HCI. The use of less invasive tongue swab samples to increase sample yield in the absence of sputum expectoration highlights the value of combination testing strategies. Immediate result notification resulting from rapid, in-home POC testing shows great promise for increasing early case detection and improving treatment uptake. In-home, POC testing strategies, when incorporated into HCI could curb ongoing community transmission and reduce the overall burden of TB. Considerations for adopting novel POC testing strategies in future active case finding programs like HCI should strongly be considered. We evaluated the cost-effectiveness of in-home, point-of-care TB testing of household contacts. The findings indicate that combined testing strategies using tongue swab and sputum specimens could significantly increase TB case detection, with modest additional program costs.

Screening of Tuberculosis Infection through Acid-Fast Bacilli Tests among Waste Workers in Gresik, Indonesia

Highlights: 1. This study was the first in Gresik, Indonesia, to conduct mass screening of tuberculosis among waste workers, comprising various demographic profiles.2. Although the tuberculosis screening of the waste workers showed negative results, mass examination using an acid-fast bacilli smear remains crucial to detect latent infections and prevent transmissions. Abstract Tuberculosis is a major source of illness and mortality worldwide. Therefore, tuberculosis screening is important to increase the number of active case-finding in a community. Bacteriological examinations can be used to initiate community-based active case-finding. Waste workers face a high risk of contracting Mycobacterium tuberculosis due to their constant exposure to waste. This study aimed to conduct bacteriological examinations to identify tuberculosis infections among waste workers in Gresik, Indonesia, who were considered a high-risk group. An analytical observational study was carried out throughout September 2023 in the Ngipik subdistrict, Gresik, East Java, Indonesia. The primary study was conducted using a cross-sectional design using interviews, measurements, and sputum examinations for all samples. The screening involved a total of 72 waste workers who had daily contact with various types of sewage and waste, including medical waste. The data were analyzed descriptively because of the constant variable. Following the analysis, the data were presented using a table and a figure. According to the acid-fast bacilli examinations, all of the samples yielded negative results. Nevertheless, this study concludes that it is imperative to carry out mass tuberculosis screening in various settings, specifically among those with a high risk. Mass screening can uncover the potential of latent tuberculosis and, thus, reduce its transmission.

Integrating molecular and radiological screening tools during community-based active case-finding for tuberculosis and COVID-19 in southern Africa

ObjectivesTo evaluate diagnostic yield and feasibility of integrating testing for TB and COVID-19 using molecular and radiological screening tools during community-based active case-finding (ACF). MethodsCommunity-based participants with presumed TB and/or COVID-19 were recruited using a mobile clinic. Participants underwent simultaneous point-of-care (POC) testing for TB (sputum; Xpert Ultra) and COVID-19 (nasopharyngeal swabs; Xpert SARS-CoV-2). Sputum culture and SARS-CoV-2 RT-PCR served as reference standards. Participants underwent ultra-portable POC chest radiography with computer-aided detection (CAD). TB infectiousness was evaluated using smear microscopy, cough aerosol sampling studies (CASS), and chest radiographic cavity detection. Feasibility of POC testing was evaluated via user-appraisals. ResultsSix hundred and one participants were enrolled, with 144/601 (24.0%) reporting symptoms suggestive of TB and/or COVID-19. 16/144 (11.1%) participants tested positive for TB, while 10/144 (6.9%) tested positive for COVID-19 (2/144 [1.4%] had concurrent TB/COVID-19). Seven (7/16 [43.8%]) individuals with TB were probably infectious. Test-specific sensitivity and specificity (95% CI) were: Xpert Ultra 75.0% (42.8-94.5) and 96.9% (92.4-99.2); Xpert SARS-CoV-2 66.7% (22.3-95.7) and 97.1% (92.7-99.2). Area under the curve (AUC) for CAD4TB was 0.90 (0.82-0.97). User appraisals indicated POC Xpert to have ‘good’ user-friendliness. ConclusionsIntegrating TB/COVID-19 screening during community-based ACF using POC molecular and radiological tools is feasible, has a high diagnostic yield, and can identity probably infectious persons.

Community-based Advocacy Communication Social Mobilization (ACSM) intervention by empowering key community leaders: Evaluation using the RE-AIM framework.

Based on the theme of World Tuberculosis (TB) Day 2018-"Wanted Leaders for TB free world," various studies and country-level project have witnessed how training leaders on TB has helped enhance TB awareness in the community. This study was conducted to evaluate the effectiveness of Advocacy Communication and Social Mobilization (ACSM) intervention strategy through key community leaders, using Reach, Effectiveness, Adoption, Implementation, Maintenance (RE-AIM) framework. This study was undertaken by the Department of Community Medicine, Sri Manakula Vinayagar Medical College and Hospital (SMVMCH), Puducherry, in the field practice area of Primary Health Centre (PHC), Thirubuvanai. The STOP TB, ENGAGE-TB, and National TB Elimination Program (NTEP) guidelines were used for interventions. Key community leaders (KCL) list (N = 117) was obtained from Mannadipet commune panchayat and PHC. The study was conducted in four phases: phase 1 (baseline): quantitative data: proportion of presumptive TB cases from notification register; phase 2 (intervention): training program for staff nurses, auxiliary nurse midwife (ANM), Accredited Social Health Activist (ASHA), and Anganwadi workers (group activity), participatory rural appraisal (PRA) activity for self-help group (SHG) leaders, and health education session for religious leaders and ex-panchayat leaders; phase 3: strengthening of ongoing activity: health education session and active case finding for TB; and phase 4: end line: outcome of the intervention, evaluated using the RE-AIM framework. As an outcome of the intervention, there was a marginal increase (21 cases) in the proportion of presumptive TB cases when comparing before (2018) and after (2019) intervention. The proportion of presumptive TB cases identified and referred by KCL was 312. A total of 77 presumptive TB cases were identified through community-based active case finding (ACF). Two sputum samples (on the spot early morning) were collected and sent for Cartridge-based nucleic acid amplification testing (CBNAAT), of which three cases were positive. This study was community led and involved leaders from diverse backgrounds, optimizing the chance of success. For sustainability, we have initiated TB support group.

Cost-Effectiveness of Community-Based Active Case Finding Strategy for Tuberculosis: Evidence From Shenzhen, China.

Active case finding (ACF) is a potentially promising approach for the early identification and treatment of tuberculosis patients. However, evidence on its cost-effectiveness, particularly in low- and middle-income countries, remains limited. This study evaluates the cost-effectiveness of a community-based ACF practice in Shenzhen, China. We employed a Markov model-based decision analytic method to assess the costs and effectiveness of 3 tuberculosis detection strategies: passive case finding (PCF), basic ACF, and advanced ACF. The analysis was conducted from a societal perspective on a dynamic cohort over a 20-year horizon, focusing on active tuberculosis (ATB) prevalence and the incremental cost-effectiveness ratio (ICER). Compared to the PCF strategy, the basic and advanced ACF strategies effectively reduced ATB cases by 6.8 and 10.2 per 100 000 population, respectively, by the final year of this 20-year period. The ICER for the basic and advanced ACF strategies were ¥14 757 and ¥8217 per quality-adjusted life-year, respectively. Both values fell below the cost-effectiveness threshold. Our findings indicate that the community-based ACF screening strategy, which targets individuals exhibiting tuberculosis symptoms, is cost-effective. This underscores the potential benefits of adopting similar community-based ACF strategies for symptomatic populations in tuberculosis-endemic areas.

Applicability of artificial intelligence-based computer-aided detection (AI–CAD) for pulmonary tuberculosis to community-based active case finding

BackgroundArtificial intelligence-based computer-aided detection (AI–CAD) for tuberculosis (TB) has become commercially available and several studies have been conducted to evaluate the performance of AI–CAD for pulmonary tuberculosis (TB) in clinical settings. However, little is known about its applicability to community-based active case-finding (ACF) for TB.MethodsWe analysed an anonymized data set obtained from a community-based ACF in Cambodia, targeting persons aged 55 years or over, persons with any TB symptoms, such as chronic cough, and persons at risk of TB, including household contacts. All of the participants in the ACF were screened by chest radiography (CXR) by Cambodian doctors, followed by Xpert test when they were eligible for sputum examination. Interpretation by an experienced chest physician and abnormality scoring by a newly developed AI–CAD were retrospectively conducted for the CXR images. With a reference of Xpert-positive TB or human interpretations, receiver operating characteristic (ROC) curves were drawn to evaluate the AI–CAD performance by area under the ROC curve (AUROC). In addition, its applicability to community-based ACFs in Cambodia was examined.ResultsTB scores of the AI–CAD were significantly associated with the CXR classifications as indicated by the severity of TB disease, and its AUROC as the bacteriological reference was 0.86 (95% confidence interval 0.83–0.89). Using a threshold for triage purposes, the human reading and bacteriological examination needed fell to 21% and 15%, respectively, detecting 95% of Xpert-positive TB in ACF. For screening purposes, we could detect 98% of Xpert-positive TB cases.ConclusionsAI–CAD is applicable to community-based ACF in high TB burden settings, where experienced human readers for CXR images are scarce. The use of AI–CAD in developing countries has the potential to expand CXR screening in community-based ACFs, with a substantial decrease in the workload on human readers and laboratory labour. Further studies are needed to generalize the results to other countries by increasing the sample size and comparing the AI–CAD performance with that of more human readers.

Community-based COVID-19 active case finding and rapid response in the Democratic Republic of the Congo: Improving case detection and response.

A community-based coronavirus disease (COVID-19) active case-finding strategy using an antigen-detecting rapid diagnostic test (Ag-RDT) was implemented in the Democratic Republic of Congo (DRC) to enhance COVID-19 case detection. With this pilot community-based active case finding and response program that was designed as a clinical, prospective testing performance, and implementation study, we aimed to identify insights to improve community diagnosis and rapid response to COVID-19. This pilot study was modeled on the DRC's National COVID-19 Response Plan and the COVID-19 Ag-RDT screening algorithm defined by the World Health Organization (WHO), with case findings implemented in 259 health areas, 39 health zones, and 9 provinces. In each health area, a 7-member interdisciplinary field team tested the close contacts (ring strategy) and applied preventive and control measures to each confirmed case. The COVID-19 testing capacity increased from 0.3 tests per 10,000 inhabitants per week in the first wave to 0.4, 1.6, and 2.2 in the second, third, and fourth waves, respectively. From January to November 2021, this capacity increase contributed to an average of 10.5% of COVID-19 tests in the DRC, with 7,110 positive Ag-RDT results for 40,226 suspected cases and close contacts who were tested (53.6% female, median age: 37 years [interquartile range: 26.0-50.0)]. Overall, 79.7% (n = 32,071) of the participants were symptomatic and 7.6% (n = 3,073) had comorbidities. The Ag-RDT sensitivity and specificity were 55.5% and 99.0%, respectively, based on reverse transcription polymerase chain reaction analysis, and there was substantial agreement between the tests (k = 0.63). Despite its limited sensitivity, the Ag-RDT has improved COVID-19 testing capacity, enabling earlier detection, isolation, and treatment of COVID-19 cases. Our findings support the community testing of suspected cases and asymptomatic close contacts of confirmed cases to reduce disease spread and virus transmission.

Portable digital X-ray for TB pre-diagnosis screening in rural communities in Nigeria.

This pilot project was conducted in hard-to-reach communities of two Niger Delta States in the South-South Region of Nigeria. To assess the usefulness of portable digital X-ray, the Delft-Light Backpack (DLB) for TB active case-finding (ACF) in hard-to-reach Niger Delta communities using the WHO 3B TB screening/diagnosis algorithm. DLB X-ray was used to screen all consenting eligible participants during community TB screening out-reaches in all hard-to-reach communities of Akwa Ibom and Cross River States in the Niger Delta, Nigeria. Participants with a CAD4TB (computer-aided detection for TB score) ⩾60 had Xpert (sputum) and/or clinical (radiograph) assessment for TB diagnosis. Data from the project were analysed for this study. A total of 8,230 participants (males: 47.2%, females: 52.8%) underwent TB screening and 1,140 (13.9%) presumptive TB cases were identified. The TB prevalence among all participants and among those with presumptive TB were respectively 1.2% and 8.6%. The number needed to screen was 84. Among people with presumptive TB, the proportion of males and females with confirmed TB was respectively 12.0% and 5.6% (P < 0.001). TB screening using DLB X-ray during community-based ACF in hard-to-reach Niger Delta communities of Nigeria showed a high TB prevalence among participants. Nationwide deployment of the instrument in hard-to-reach areas is recommended.

Increasing TB/HIV Case Notification through an Active Case-Finding Approach among Rural and Mining Communities in Northwest Tanzania.

While Tanzania is among the high TB burden countries to reach the WHO's End TB 2030 milestones, 41% of the people estimated to have had TB in 2020 were not diagnosed and notified. As part of the response to close the TB treatment coverage gap, SHDEPHA+ Kahama conducted a TB REACH active case-finding (ACF) intervention among rural and mining communities in Northwest Tanzania to increase TB/HIV case notification from July 2017 to June 2020. The intervention successfully linked marginalized mining communities with integrated TB/HIV screening, diagnostic, and referral services, screening 144,707 people for TB of whom 24,200 were tested for TB and 4,478 were tested for HIV, diagnosing 1,499 people with TB and 1,273 people with HIV (including at least 154 people with TB/HIV coinfection). The intervention revealed that community-based ACF can ensure high rates of linkage to care among hard-to-reach populations for TB. Providing integrated TB and HIV screening and diagnostic services during evening hours (Moonlight Events) in and around mining settlements can yield a large number of people with undiagnosed TB and HIV. For TB, this is true not only amongst miners but also FSW living in the same communities, who appear to be at similar or equally high risk of infection. Local NGOs can help to bridge the TB treatment coverage gap and to improve TB and HIV health outcomes by linking these marginalized groups with public sector services. Capturing the number of referrals arriving at CTCs is an important next step to identify how well the integrated TB/HIV outreach services operate and how they can be strengthened.

Do community-based active case-finding interventions have indirect impacts on wider TB case detection and determinants of subsequent TB testing behaviour? A systematic review.

Community-based active case-finding (ACF) may have important impacts on routine TB case-detection and subsequent patient-initiated diagnosis pathways, contributing "indirectly" to infectious diseases prevention and care. We investigated the impact of ACF beyond directly diagnosed patients for TB, using routine case-notification rate (CNR) ratios as a measure of indirect effect. We systematically searched for publications 01-Jan-1980 to 13-Apr-2020 reporting on community-based ACF interventions compared to a comparison group, together with review of linked manuscripts reporting knowledge, attitudes, and practices (KAP) outcomes or qualitative data on TB testing behaviour. We calculated CNR ratios of routine case-notifications (i.e. excluding cases identified directly through ACF) and compared proxy behavioural outcomes for both ACF and comparator communities. Full text manuscripts from 988 of 23,883 abstracts were screened for inclusion; 36 were eligible. Of these, 12 reported routine notification rates separately from ACF intervention-attributed rates, and one reported any proxy behavioural outcomes. Two further studies were identified from screening 1121 abstracts for linked KAP/qualitative manuscripts. 8/12 case-notification studies were considered at critical or serious risk of bias. 8/11 non-randomised studies reported bacteriologically-confirmed CNR ratios between 0.47 (95% CI:0.41-0.53) and 0.96 (95% CI:0.94-0.97), with 7/11 reporting all-form CNR ratios between 0.96 (95% CI:0.88-1.05) and 1.09 (95% CI:1.02-1.16). One high-quality randomised-controlled trial reported a ratio of 1.14 (95% CI 0.91-1.43). KAP/qualitative manuscripts provided insufficient evidence to establish the impact of ACF on subsequent TB testing behaviour. ACF interventions with routine CNR ratios >1 suggest an indirect effect on wider TB case-detection, potentially due to impact on subsequent TB testing behaviour through follow-up after a negative ACF test or increased TB knowledge. However, data on this type of impact are rarely collected. Evaluation of routine case-notification, testing and proxy behavioural outcomes in intervention and comparator communities should be included as standard methodology in future ACF campaign study designs.

Economic Evaluation of Community Tuberculosis Active Case-Finding Approaches in Cambodia: A Quasi-Experimental Study.

This study aimed to estimate the costs and incremental cost-effectiveness of two community-based tuberculosis (TB) active case-finding (ACF) strategies in Cambodia. We also assessed the number needed to screen and test to find one TB case. Program and national TB notification data from a quasi-experimental study of a cohort of people with TB in 12 intervention operational districts (ODs) and 12 control ODs between November 2018 and December 2019 were analyzed. Two ACF interventions (ACF seed-and-recruit (ACF SAR) model and one-off roving (one-off) ACF) were implemented concurrently. The matched control sites included PCF only. We estimated costs using the program and published data in Cambodia. The primary outcome was disability-adjusted life years (DALY) averted over 14 months. We considered the gross domestic product per capita of Cambodia in 2018 as the cost-effectiveness threshold. ACF SAR needed to test 7.7 people with presumptive TB to identify one all-forms TB, while one-off ACF needed to test 22.4. The costs to diagnose one all-forms TB were USD 458 (ACF SAR) and USD 191 (one-off ACF). The incremental cost per DALY averted was USD 257 for ACF SAR and USD 204 for one-off ACF. Community-based ACF interventions that targeted key populations for TB in Cambodia were highly cost-effective.

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

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

Comparative Yield of Tuberculosis during Active Case Finding Using GeneXpert or Smear Microscopy for Diagnostic Testing in Nepal: A Cross-Sectional Study.

This study compared the yield of tuberculosis (TB) active case finding (ACF) interventions applied under TB REACH funding. Between June 2017 to November 2018, Birat Nepal Medical Trust identified presumptive cases using simple verbal screening from three interventions: door-to-door screening of social contacts of known index cases, TB camps in remote areas, and screening for hospital out-patient department (OPD) attendees. Symptomatic individuals were then tested using smear microscopy or GeneXpert MTB/RIF as first diagnostic test. Yield rates were compared for each intervention and diagnostic method. We evaluated additional cases notified from ACF interventions by comparing case notifications of the intervention and control districts using standard TB REACH methodology. The project identified 1092 TB cases. The highest yield was obtained from OPD screening at hospitals (n = 566/1092; 52%). The proportion of positive tests using GeneXpert (5.5%, n = 859/15,637) was significantly higher than from microscopy testing 2% (n = 120/6309). (OR = 1.4; 95%CI = 1.12–1.72; p = 0.0026). The project achieved 29% additionality in case notifications in the intervention districts demonstrating that GeneXpert achieved substantially higher case-finding yields. Therefore, to increase national case notification for TB, Nepal should integrate OPD screening using GeneXpert testing in every district hospital and scale up of community-based ACF of TB patient contacts nationally.

Community-Based Active Case Finding to Increase Tuberculosis Case Detection and Treatment Success Rate in High Tuberculosis Burden Areas of Arsi Zone, Oromia

<i>Background</i>: More than 9 million new cases of tuberculosis (TB) occur per year and about two million people die of TB. The probable cause of death is delay in diagnosis, low case detection rate and treatment success rate. Due to the low potential of tuberculosis (TB) microscopic examination and the need to increase rate of new TB case identification is also increased. <i>Objective</i>: To determine magnitude of active tuberculosis cases, evaluate the performance of LED-FM and X-pert MTB/RIF assay and characterize treatment outcome <i>Methods</i>: The door-to-door survey for TB in high TB burden areas of Arsi zone was performed. The participants were screened based on typical TB symptoms. The sputum samples were collected and transported to the laboratories. Culture, LED-FM and X-pert MTB/RIF assay were performed to confirm tuberculosis infection. Result was communicated through cell phone or short message system (SMS) for issuing of positive results. The health extension worker would contact diagnosed patients referred to their local health center for care. Finally, the performance of diagnostic tests, case detection rate and treatment success were determined. <i>Result</i>: In this study 344 pulmonary TB suspected study participants were involved from the three study sites. Based on the LED microscope results the general prevalence of pulmonary TB among the current study participants was 2.3%. On the other hand Gene X-pert MTB/RIF assay could show that 9 (2.6%) of the study participants became positive for pulmonary TB cases. There was 1 (0.3%) discordant result between the two assay methods. LED microscope missed one TB suspected case which was detected by Gen X-pert MTB/RIF assay and then confirmed by LJ culture media and become positive for pulmonary TB. Hence, the overall prevalence of pulmonary TB in our current study became 2.6% with 95% CI (1.2-4.5) using LJ culture media as tiebreaker. Of 344 study participants in this study, 9 (2.6%) were positive for pulmonary TB and given first line anti-TB drugs. Of the nine pulmonary TB test positive study participants who had prescribed with first line anti-TB drugs in which 2 (22.2%) were known to be cured as well as 7 (77.8%) had completed the treatment regimen prescribed for them.

Economic Evaluation of Community Tuberculosis Active Case Finding Approaches in Cambodia

Background: We conducted an economic evaluation of two community tuberculosis (TB) active case finding (ACF) strategies in Cambodia by assessing the cost per disability-adjusted life years (DALY) averted among people with TB. Methods: We analyzed program and national TB notification data from a cohort of people with TB in 12 intervention operational districts (ODs) and 12 control ODs between November 2018 and February 2020. The interventions comprised—1) ACF using a seed-and-recruit model and 2) one-off roving ACF that were implemented concurrently. Passive case finding, a default setup in the health system, was continuously present in both the intervention and control areas. We estimated costs using the program and previously published primary cost data in Cambodia. The primary outcome was the cost per DALY averted among people with TB in the intervention sites compared to the control sites. We considered an intervention to be cost-effective if the cost per DALY averted was lower than the gross domestic product per capita of Cambodia (US$ 1643 in 2018). Findings: In total, 12074 were screened and tested via the seed-and-recruit model and 51636 via the one-off roving ACF model. The former needed to test 7·7 presumptive TB to identify 1577 all-forms TB, while the latter needed to test 22·4 to identify 2303 all-forms TB. The cost per DALY averted was US$ 237 for ACF using a seed-and-recruit model, US$ 164 for one-off roving ACF. Interpretation: Community-based ACF interventions that targeted engagements with key populations for TB in Cambodia were highly cost-effective. Funding Statement: This study was funded by the Stop TB Partnership TB REACH Grant. Declaration of Interests: We declare no competing interests. Ethics Approval Statement: This study was approved by the National Ethics Committee for Health Research Cambodia (112/NECHR). A waiver of consent was granted due to the retrospective nature of this study, the minimal risk to rights and welfare of the participants, and the lack of practicality to obtain consent.

Islands of Tuberculosis Elimination: An Evaluation of Community-Based Active Case Finding in North Sumatra, Indonesia.

Community-based active case finding (ACF) is needed to reach key/vulnerable populations with limited access to tuberculosis (TB) care. Published reports of ACF interventions in Indonesia are scarce. We conducted an evaluation of a multicomponent community-based ACF intervention as it scaled from one district to nine in Nias and mainland North Sumatra. Community and health system support measures including laboratory strengthening, political advocacy, sputum transport, and community awareness were instituted. ACF was conducted in three phases: pilot (18 months, 1 district), intervention (12 months, 4 districts) and scale-up (9 months, 9 districts). The pilot phase identified 215 individuals with bacteriologically positive (B+) TB, representing 42% of B+ TB notifications. The intervention phase yielded 509, representing 54% of B+ notifications and the scale-up phase identified 1345 individuals with B+ TB (56% of notifications). We observed large increases in B+ notifications on Nias, but no overall change on the mainland despite district variation. Overall, community health workers screened 377,304 individuals of whom 1547 tested positive, and 95% were initiated on treatment. Our evaluation shows that multicomponent community-based ACF can reduce the number of people missed by TB programs. Community-based organizations are best placed for accessing and engaging hard to reach populations and providing integrated support which can have a large positive effect on TB notifications.

Community-based active tuberculosis case finding using a symptom-based screening tool in the Volta Region, Ghana

BackgroundEarly tuberculosis case detection is important for early commencement of treatment to improve treatment outcomes and also to prevent community spread of the disease. However, there is a paucity of data in Ghana on the efficiency of the symptom-based screening tool (SBS tool) to detect Mycobacterium tuberculosis in the communities. Therefore, this study assessed the usefulness of the SBS tool for community-based active case finding in the Volta Region of Ghana. Methods and materialsThis cross-sectional study used house-to-house and durbar screening approaches for active tuberculosis (TB) case searching from six communities, three each from the Ketu South (high TB risk) and Akatsi North (low TB risk) districts in the Volta Region of Ghana. Random eligible participants were screened with the SBS tool to identify presumptive TB cases. One sputum sample was collected from each person with presumptive TB for detection of M. tuberculosis by the GeneXpert real-time technique. ResultsA total of 1,025 people were screened from a population of 40,462, from which 332 (32.4%) were presumed to have M. tuberculosis infection. Of the 332 presumptive TB cases, 63.9% were obtained through house-to-house screening, while 36.1% were obtained through community durbar screening. Six M. tuberculosis-positive cases (with one rifampicin resistance) were detected by house-to-house screening but not from community durbar samples, yielding an overall prevalence of 15 per 100,000 population. Among TB symptoms screened and analysed, association existed only between night sweat and TB case detection (χ2 = 3.9, P = 0.049). ConclusionAlthough cumbersome and capital intensive, community-based active case searching through house-to-house screening using the SBS tool proved effective in detecting M. tuberculosis in the communities.

Spatial distribution of people diagnosed with tuberculosis through routine and active case finding: a community-based study in Kampala, Uganda

BackgroundRoutine tuberculosis (TB) notifications are geographically heterogeneous, but their utility in predicting the location of undiagnosed TB cases is unclear. We aimed to identify small-scale geographic areas with high TB notification rates based on routinely collected data and to evaluate whether these areas have a correspondingly high rate of undiagnosed prevalent TB.MethodsWe used routinely collected data to identify geographic areas with high TB notification rates and evaluated the extent to which these areas correlated with the location of undiagnosed cases during a subsequent community-wide active case finding intervention in Kampala, Uganda. We first enrolled all adults who lived within 35 contiguous zones and were diagnosed through routine care at four local TB Diagnosis and Treatment Units. We calculated average monthly TB notification rates in each zone and defined geographic areas of “high risk” as zones that constituted the 20% of the population with highest notification rates. We compared the observed proportion of TB notifications among residents of these high-risk zones to the expected proportion, using simulated estimates based on population size and random variation alone. We then evaluated the extent to which these high-risk zones identified areas with high burdens of undiagnosed TB during a subsequent community-based active case finding campaign using a chi-square test.ResultsWe enrolled 45 adults diagnosed with TB through routine practices and who lived within the study area (estimated population of 49 527). Eighteen zones reported no TB cases in the 9-month period; among the remaining zones, monthly TB notification rates ranged from 3.9 to 39.4 per 100 000 population. The five zones with the highest notification rates constituted 62% (95% CI: 47–75%) of TB cases and 22% of the population–significantly higher than would be expected if population size and random chance were the only determinants of zone-to-zone variation (48%, 95% simulation interval: 40–59%). These five high-risk zones accounted for 42% (95% CI: 34–51%) of the 128 cases detected during the subsequent community-based case finding intervention, which was significantly higher than the 22% expected by chance (P < 0.001) but lower than the 62% of cases notified from those zones during the pre-intervention period (P = 0.02).ConclusionsThere is substantial heterogeneity in routine TB notification rates at the zone level. Using facility-based TB notification rates to prioritize high-yield areas for active case finding could double the yield of such case-finding interventions.

Mobilising community networks for early identification of tuberculosis and treatment initiation in Cambodia: an evaluation of a seed-and-recruit model.

Background and objectivesThe effects of active case finding (ACF) models that mobilise community networks for early identification and treatment of tuberculosis (TB) remain unknown. We investigated and compared the effect of community-based ACF using a seed-and-recruit model with one-off roving ACF and passive case finding (PCF) on the time to treatment initiation and identification of bacteriologically confirmed TB.MethodsIn this retrospective cohort study conducted in 12 operational districts in Cambodia, we assessed relationships between ACF models and: 1) the time to treatment initiation using Cox proportional hazards regression; and 2) the identification of bacteriologically confirmed TB using modified Poisson regression with robust sandwich variance.ResultsWe included 728 adults with TB, of whom 36% were identified via the community-based ACF using a seed-and-recruit model. We found community-based ACF using a seed-and-recruit model was associated with shorter delay to treatment initiation compared to one-off roving ACF (hazard ratio 0.81, 95% CI 0.68–0.96). Compared to one-off roving ACF and PCF, community-based ACF using a seed-and-recruit model was 45% (prevalence ratio (PR) 1.45, 95% CI 1.19–1.78) and 39% (PR 1.39, 95% CI 0.99–1.94) more likely to find and detect bacteriologically confirmed TB, respectively.ConclusionMobilising community networks to find TB cases was associated with early initiation of TB treatment in Cambodia. This approach was more likely to find bacteriologically confirmed TB cases, contributing to the reduction of risk of transmission within the community.

Role of community-based active case finding in screening tuberculosis in Yunnan province of China

BackgroundThe barriers to access diagnosis and receive treatment, in addition to insufficient case identification and reporting, lead to tuberculosis (TB) spreads in communities, especially among hard-to-reach populations. This study evaluated a community-based active case finding (ACF) strategy for the detection of tuberculosis cases among high-risk groups and general population in China between 2013 and 2015.MethodsThis retrospective cohort study conducted an ACF in ten communities of Dongchuan County, located in northeast Yunnan Province between 2013 and 2015; and compared to 136 communities that had passive case finding (PCF). The algorithm for ACF was: 1) screen for TB symptoms among community enrolled residents by home visits, 2) those with positive symptoms along with defined high-risk groups underwent chest X-ray (CXR), followed by sputum microscopy confirmation. TB incidence proportion and the number needed to screen (NNS) to detect one case were calculated to evaluate the ACF strategy compared to PCF, chi-square test was applied to compare the incidence proportion of TB cases’ demography and the characteristics for detected cases under different strategies. Thereafter, the incidence rate ratio (IRR) and multiple Fisher’s exact test were applied to compare the incidence proportion between general population and high-risk groups. Patient and diagnostic delays for ACF and PCF were compared by Wilcoxon rank sum test.ResultsA total of 97 521 enrolled residents were visited with the ACF cumulatively, 12.3% were defined as high-risk groups or had TB symptoms. Sixty-six new TB patients were detected by ACF. There was no significant difference between the cumulative TB incidence proportion for ACF (67.7/100000 population) and the prevalence for PCF (62.6/100000 population) during 2013 to 2015, though the incidence proportion in ACF communities decreased after three rounds active screening, concurrent with the remained stable prevalence in PCF communities. The cumulative NNS were 34, 39 and 29 in HIV/AIDS infected individuals, people with positive TB symptoms and history of previous TB, respectively, compared to 1478 in the general population. The median patient delay under ACF was 1 day (Interquartile range, IQR: 0–27) compared to PCF with 30 days (IQR: 14–61).ConclusionsThis study confirmed that massive ACF was not effective in general population in a moderate TB prevalence setting. The priority should be the definition and targeting of high-risk groups in the community before the screening process is launched. The shorter time interval of ACF between TB symptoms onset and linkage to healthcare service may decrease the risk of TB community transmission. Furthermore, integrated ACF strategy in the National Project of Basic Public Health Service may have long term public health impact.