Test and Treat TB: a pilot trial of GeneXpert MTB/RIF screening on a mobile HIV testing unit in South Africa

Bassett, Ingrid V.; Forman, Leah S; Govere, Sabina; Thulare, Hilary; Frank, Simone C; Mhlongo, Bright; Losina, Elena

doi:10.1186/s12879-019-3738-4

Cited by 15 publications

(10 citation statements)

References 20 publications

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“…An alternative approach would be to deploy mobile laboratories with high-capacity systems capable of performing many tests simultaneously and equipped with appropriate biocontainment equipment. Such mobile laboratory capacity has already been deployed to find active cases of tuberculosis among at-risk populations in South Africa (18). Similar mobile laboratory capacity could potentially be made available in the current outbreak and potential future seasonal outbreaks and could be used to find active cases in nursing homes and for testing other less ambulatory populations, with results available on site and in an actionable time frame.…”

Section: Discussionmentioning

confidence: 99%

Multicenter Evaluation of the Cepheid Xpert Xpress SARS-CoV-2 Test

Loeffelholz¹,

et al. 2020

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48 Background. Nucleic acid amplification tests (NAATs) are the primary means of 49 identifying acute infections caused by severe acute respiratory syndrome coronavirus 2 50 (SARS-CoV-2). Accurate and fast test results may permit more efficient use of protective and 51 isolation resources and allow for rapid therapeutic interventions. 52 Methods. We evaluated the analytical and clinical performance characteristics of the Xpert ® 53 Xpress SARS-CoV-2 (Xpert) test, a rapid, automated molecular test for SARS-CoV-2. 54 Analytical sensitivity and specificity/interference were assessed with infectious SARS-CoV-2, 55 other infectious coronavirus species including SARS-CoV, and 85 nasopharyngeal swab 56 specimens positive for other respiratory viruses including endemic human coronaviruses 57 (hCoVs). Clinical performance was assessed using 483 remnant upper and lower respiratory 58 specimens previously analyzed by standard of care (SOC) NAATs. 59 Results. The limit of detection of the Xpert test was 0.01 plaque forming units (PFU)/mL. 60 Other hCoVs, including Middle East Respiratory Syndrome coronavirus, were not detected by 61 the Xpert test. SARS-CoV, a closely related species in the Sarbecovirus subgenus, was 62 detected by a broad-range target (E) but was distinguished from SARS-CoV-2 (SARS-CoV-2-63 specific N2 target). Compared to SOC NAATs, the positive agreement of the Xpert test was 64 219/220 (99.5%) and the negative agreement was 250/261 (95.8%). A third tie-breaker 65 NAAT resolved all but three of the discordant results in favor the Xpert test. 66 Conclusions. The Xpert test provided sensitive and accurate detection of SARS-CoV-2 in a 67 variety of upper and lower respiratory tract specimens. The high sensitivity and fast time to 68 results of approximately 45 minutes may impact patient management. 69 70 Laboratory diagnosis of infections caused by severe acute respiratory syndrome coronavirus 2 72 (SARS-CoV-2) is usually accomplished by performing nucleic acid amplification tests 73 (NAATs) on respiratory tract specimens. An antibody response is often not detected in the 74 first week to ten days of symptoms and antibody testing is therefore generally unhelpful for 75 acute diagnosis(1-3), with virus isolation in culture presenting significant biosafety risks. 76 Upper respiratory tract (URT) specimens such as nasopharyngeal swabs (NPS) and 77 oropharyngeal swabs (OPS) generally have high SARS-CoV-2 viral loads upon symptom 78 onset.(2, 4-6) URT specimens may also have detectable RNA during the pre-symptomatic 79 period(7), and pediatric patients who remain asymptomatic through the entire course of 80 on June 9, 2020 by guest http://jcm.asm.org/ Downloaded from 4 infection can persistently shed RNA in URT specimens for two weeks or longer.(4, 8) 81 Importantly, NPS may have higher viral loads than OPS.(6) Lower respiratory tract (LRT) 82 specimens including sputum(7, 9) and tracheal aspirates(10) (TA) are often positive for RNA 83 early in disease and remain positive longer than URT sources.(5) 84 NAATs are...

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Section: Discussionmentioning

confidence: 99%

Multicenter Evaluation of the Cepheid Xpert Xpress SARS-CoV-2 Test

Loeffelholz¹,

et al. 2020

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“…The introduction of GeneXpert MTB/RIF has greatly improved TB case finding; however, this technology has been mainly relegated to laboratories and healthcare facilities [39,40]. Recent intensified case finding studies have explored the feasibility and effectiveness of integrating GeneXpert platforms into community‐based mobile HIV testing vans [41,42]. Given the need to improve active case finding and linkage to care amongst household contacts of TB patients, we adapted a GeneXpert single module (GX‐I) instrument for portability and use during household contact tracing investigations [43].…”

Section: Introductionmentioning

confidence: 99%

“I got tested at home, the help came to me”: acceptability and feasibility of home‐based TB testing of household contacts using portable molecular diagnostics in South Africa

Medina‐Marino

Vos

Bezuidenhout

et al. 2021

Tropical Med Int Health

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Objective The effectiveness of household contact investigations is limited by low referral uptake for clinic‐based TB testing by symptomatic household contacts. We qualitatively investigated the acceptability and perceived benefits of home‐based TB testing using a portable GeneXpert‐I instrument (GX‐I) in an urban South African township. Methods In‐depth interviews were conducted with household contacts tested and those that observed testing. Semi‐structured interviews explored household contact’s understanding of TB, perceptions of the GX‐I device and testing procedures, confidentiality, willingness to refer others, and views on home‐ vs. clinic‐based testing. Focus group discussions with home‐based TB testing implementing staff assessed operational considerations for scale‐up. Data were analysed using a constant comparison approach to qualitatively evaluate the acceptability and feasibility of home‐based TB testing. Results Thirty in‐depth interviews and two focus group discussions were conducted. Observing one’s own sputum being tested resulted in an emergent trust in home‐based TB testing, the GX‐I device and one’s test results. Home‐based TB testing was considered convenient, helped to overcome apathy towards testing and mitigated barriers to clinic‐based testing. Perceptions that home‐based TB testing contributes to improved household and community health resulted in an emergent theme of alleviation of health insecurities. Operational concerns regarding inadvertent disclosure of one’s diagnosis to household members and time spent in people’s homes were identified. Conclusions Home‐based TB testing was acceptable and feasible. Individuals expressed belief in the machine by being able to witness the testing process. Though most themes mirrored qualitative studies of home‐based HIV testing, the alleviation of health insecurities theme is unique to home‐based TB testing. Future research must evaluate the impact of home‐based TB testing on case finding yield, time‐to‐treatment initiation and household outcomes.

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“…The higher cost of mobile testing should be weighed against the impact of earlier diagnosis, improved coverage, same-day treatment and care, as well as reduced loss to follow-up. 17 , 28 , 29 , 30 , 31 Mobile testing as an extension of laboratory testing could also see its higher costs offset by high volume laboratory testing, as bulk testing is still reserved for the laboratory service. The findings of this study confirmed that mobile testing is 3.2 times more expensive than conventional laboratory testing on the same GeneXpert testing platform.…”

Section: Discussionmentioning

confidence: 99%

“…Various studies have demonstrated that mobile testing is feasible, improves access to diagnostics, and may improve linkage to care and decrease time to treatment. 14 , 15 , 16 , 17 A local study has reported that linkage to tuberculosis treatment was not associated with either sex or service type (mobile versus stand-alone), but older patients were less likely to be linked to tuberculosis treatment. 15 Mobile testing for HIV, tuberculosis and, more recently, severe acute respiratory syndrome coronavirus 2 can bring diagnostics to where it is needed in high-burden or outbreak communities.…”

Section: Introductionmentioning

confidence: 99%

Establishing the cost of Xpert MTB/RIF mobile testing in high-burden peri-mining communities in South Africa

Cassim

Coetzee

Makuraj

et al. 2021

African Journal of Laboratory Medicine

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Background: Globally, tuberculosis remains a major cause of mortality, with an estimated 1.3 million deaths per annum. The Xpert MTB/RIF assay is used as the initial diagnostic test in the tuberculosis diagnostic algorithm. To extend the national tuberculosis testing programme in South Africa, mobile units fitted with the GeneXpert equipment were introduced to high-burden peri-mining communities.Objective: This study sought to assess the cost of mobile testing compared to traditional laboratory-based testing in a peri-mining community setting.Methods: Actual cost data for mobile and laboratory-based Xpert MTB/RIF testing from 2018 were analysed using a bottom-up ingredients-based approach to establish the annual equivalent cost and the cost per result. Historical cost data were obtained from supplier quotations and the local enterprise resource planning system. Costs were obtained in rand and reported in United States dollars (USD).Results: The mobile units performed 4866 tests with an overall cost per result of $49.16. Staffing accounted for 30.7% of this cost, while reagents and laboratory equipment accounted for 20.7% and 20.8%. The cost per result of traditional laboratory-based testing was $15.44 US dollars (USD). The cost for identifying a tuberculosis-positive result using mobile testing was $439.58 USD per case, compared to $164.95 USD with laboratory-based testing.Conclusion: Mobile testing is substantially more expensive than traditional laboratory services but offers benefits for rapid tuberculosis case detection and same-day antiretroviral therapy initiation. Mobile tuberculosis testing should however be reserved for high-burden communities with limited access to laboratory testing where immediate intervention can benefit patient outcomes.

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Test and Treat TB: a pilot trial of GeneXpert MTB/RIF screening on a mobile HIV testing unit in South Africa

Cited by 15 publications

References 20 publications

Multicenter Evaluation of the Cepheid Xpert Xpress SARS-CoV-2 Test

Multicenter Evaluation of the Cepheid Xpert Xpress SARS-CoV-2 Test

“I got tested at home, the help came to me”: acceptability and feasibility of home‐based TB testing of household contacts using portable molecular diagnostics in South Africa

Establishing the cost of Xpert MTB/RIF mobile testing in high-burden peri-mining communities in South Africa

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