Novel FujiLAM assay to detect tuberculosis in HIV-positive ambulatory patients in four African countries: a diagnostic accuracy study.

BACKGROUND: Development of rapid biomarker-based tests that can diagnose tuberculosis using non-sputum samples is a priority for tuberculosis control. We aimed to compare the diagnostic accuracy of the novel Fujifilm SILVAMP TB LAM (FujiLAM) assay with the WHO-recommended Alere Determine TB-LAM Ag test (AlereLAM) using urine samples from HIV-positive patients. METHODS: We did a diagnostic accuracy study at five outpatient public health facilities in Uganda, Kenya, Mozambique, and South Africa. Eligible patients were ambulatory HIV-positive individuals (aged ≥15 years) with symptoms of tuberculosis irrespective of their CD4 T-cell count (group 1), and asymptomatic patients with advanced HIV disease (CD4 count <200 cells per µL, or HIV clinical stage 3 or 4; group 2). All participants underwent clinical examination, chest x-ray, and blood sampling, and were requested to provide a fresh urine sample, and two sputum samples. FujiLAM and AlereLAM urine assays, Xpert MTB/RIF Ultra assay on sputum or urine, sputum culture for Mycobacterium tuberculosis, and CD4 count were systematically carried out for all patients. Sensitivity and specificity of FujiLAM and AlereLAM were evaluated against microbiological and composite reference standards. FINDINGS: Between Aug 24, 2020 and Sept 21, 2021, 1575 patients (823 [52·3%] women) were included in the study: 1031 patients in group 1 and 544 patients in group 2. Tuberculosis was microbiologically confirmed in 96 (9·4%) of 1022 patients in group 1 and 18 (3·3%) of 542 patients in group 2. Using the microbiological reference standard, FujiLAM sensitivity was 60% (95% CI 51-69) and AlereLAM sensitivity was 40% (31-49; p<0·001). Among patients with CD4 counts of less than 200 cells per µL, FujiLAM sensitivity was 69% (57-79) and AlereLAM sensitivity was 52% (40-64; p=0·0218). Among patients with CD4 counts of 200 cells per µL or higher, FujiLAM sensitivity was 47% (34-61) and AlereLAM sensitivity was 24% (14-38; p=0·0116). Using the microbiological reference standard, FujiLAM specificity was 87% (95% CI 85-89) and AlereLAM specificity was 86% (95 CI 84-88; p=0·941). FujiLAM sensitivity varied by lot number from 48% (34-62) to 76% (57-89) and specificity from 77% (72-81) to 98% (93-99). INTERPRETATION: Next-generation, higher sensitivity urine-lipoarabinomannan assays are potentially promising tests that allow rapid tuberculosis diagnosis at the point of care for HIV-positive patients. However, the variability in accuracy between FujiLAM lot numbers needs to be addressed before clinical use. FUNDING: ANRS and Médecins Sans Frontières.

Engineering a sustainable future for point-of-care diagnostics and single-use microfluidic devices.

Single-use, disposable, point-of-care diagnostic devices carry great promise for global health, including meeting urgent needs for testing and diagnosis in places with limited laboratory facilities. Unfortunately, the production and disposal of single-use devices, whether in lateral flow assay, cartridges, cassettes, or lab-on-chip microfluidic format, also poses significant challenges for environmental and human health. Point-of-care devices are commonly manufactured from unsustainable polymeric materials derived from fossil sources. Their disposal often necessitates incineration to reduce infection risk, thereby creating additional release of CO2. Many devices also contain toxic chemicals, such as cyanide derivatives, that are damaging to environmental and human health if not disposed of safely. Yet, in the absence of government regulatory frameworks, safe and sustainable waste management for these novel medical devices is often left unaddressed. There is an urgent need to find novel solutions to avert environmental and human harm from these devices, especially in low- and middle-income countries where waste management infrastructure is often weak and where the use of point-of-care tests is projected to rise in coming years. We review here common materials used in the manufacture of single-use point-of-care diagnostic tests, examine the risks they pose to environmental and human health, and investigate replacement materials that can potentially reduce the impact of microfluidic devices on the production of harmful waste. We propose solutions available to point-of-care test developers to start embedding sustainability at an early stage in their design, and to reduce their non-renewable plastic consumption in research and product development.

Feasibility and acceptability of using the novel urine-based FujiLAM test to detect tuberculosis: A multi-country mixed-methods study.

Background: The novel urine-based FujiLAM test identifies tuberculosis in HIV-positive patients but may be challenging to use at point-of-care (POC). Objectives: We assessed the feasibility and acceptability of using the FujiLAM test at point of care in outpatient settings. Methods: We conducted a mixed methods study in four outpatient settings in Kenya, Mozambique, South Africa, and Uganda between November 2020 and September 2021. The test was performed at POC in existing clinic laboratories and consultation spaces. We performed direct observations in the four health facilities, individual questionnaires, proficiency testing evaluations, and individual interviews among healthcare workers performing the FujiLAM test (healthcare workers), and group discussions with programme managers. Results: Overall, 18/19 (95%) healthcare workers and 14/14 (100%) managers agreed to participate in the study. Most assessed healthcare workers, including lay health workers (10/11; 91%), met the minimum required theoretical knowledge and practical skill in performing the FujiLAM test. Most healthcare workers (17/18; 94%) found the FujiLAM test overall "Easy/Very easy" to perform. Some challenges were mentioned: many timed steps (5/18; 28%); ensuring correct incubation period (5/18; 28%); test result readability (4/18; 22%); and difficulties with cartridge buttons (3/18; 17%). Half of the healthcare workers regularly performing the test (4/7; 57%) found it "Easy" to integrate into routine activities. Most healthcare workers and managers believed that any healthcare worker could perform the test after adequate training. Conclusions: Implementing the FujiLAM test in outpatient POC settings is feasible and acceptable to healthcare workers and managers. This test can be performed in various clinic locations by any healthcare worker. The timed, multi-step test procedure is challenging and may affect the workload in resource-constrained health facilities.

Lay testing cadres and point-of-care diagnostic tests for HIV and other diseases: An essential combination in health service delivery.

Zibusiso Ndlovu and Tom Ellman discuss the potential value of task sharing in provision of testing for HIV and other infectious diseases.

Framework for the implementation of advanced HIV disease diagnostics in sub-Saharan Africa: programmatic perspectives.

Patients with advanced HIV disease have a high risk of mortality, mainly from tuberculosis and cryptococcal meningitis. The advanced HIV disease management package recommended by WHO, which includes diagnostics, therapeutics, and patient psychosocial support, is barely implemented in many different countries. Here, we present a framework for the implementation of advanced HIV disease diagnostics. Laboratory and point-of-care-based reflex testing, coupled with provider-initiated requested testing, for cryptococcal antigen and urinary Mycobacterium tuberculosis lipoarabinomannan antigen, should be done for all patients with CD4+ cell counts of 200 cells per µL or less. Implementation of the advanced HIV disease package should be encouraged within primary health-care facilities and task shifting of testing to lay cadres could facilitate access to rapid results. Implementation of differentiated antiretroviral therapy delivery models can allow clinicians enough time to focus on the management of patients with advanced HIV disease. Efficient up-referral and post-discharge systems, including the development of patient-centric advanced HIV disease literacy, are also crucial. Implementation of the advanced HIV disease package is feasible at all health-care levels, and it should be part of the core of the global response towards ending AIDS as a public health threat.

Diagnostic performance and usability of the VISITECT CD4 semi-quantitative test for advanced HIV disease screening.

BACKGROUND: In sub-Saharan Africa, a third of people starting antiretroviral therapy and majority of patients returning to HIV-care after disengagement, present with advanced HIV disease (ADH), and are at high risk of mortality. Simplified and more affordable point-of-care (POC) diagnostics are required to increase access to prompt CD4 cell count screening for ambulatory and asymptomatic patients. The Visitect CD4 Lateral Flow Assay (LFA) is a disposable POC test, providing a visually interpreted result of above or below 200 CD4cells/mm3. This study evaluated the diagnostic performance of this index test. METHODS: Consenting patients above 18years of age and eligible for CD4 testing were enrolled in Nsanje district hospital (Malawi), Gutu mission hospital (Zimbabwe) and Centre hopitalier de Kabinda (DRC). A total of 708 venous blood samples were tested in the index test and in the BD FACSCount assay (reference test method) in the laboratories (Phase 1) to determine diagnostic accuracy. A total of 433 finger-prick (FP) samples were tested on the index test at POC by clinicians (Phase 2) and a self-completed questionnaire was administered to all testers to explore usability of the index test. RESULTS: Among 708 patients, 67.2% were female and median CD4 was 297cells/mm3. The sensitivity of the Visitect CD4 LFA using venous blood in the laboratory was 95.0% [95% CI: 91.3-97.5] and specificity was 81.9% [95% CI: 78.2-85.2%]. Using FP samples, the sensitivity of the Visitect CD4 LFA was 98.3% [95% CI: 95.0-99.6] and specificity was 77.2% [95% CI: 71.6-82.2%]. Usability of the Visitect CD4 LFA was high across the study sites with 97% successfully completed tests. Due to the required specific multiple incubation and procedural steps during the Visitect CD4 LFA testing, few health workers (7/26) were not confident to manage testing whilst multi-tasking in their clinical work. CONCLUSIONS: Visitect CD4 LFA is a promising test for decentralized CD4 screening in resource-limited settings, without access to CD4 testing and and it can trigger prompt management of patients with AHD. Lay health cadres should be considered to conduct Visitect CD4 LFA testing in PHCs as well as coordinating all other POC quality assurance.

Feasibility of using Determine TB-LAM to diagnose tuberculosis in HIV-positive patients in programmatic conditions: a multisite study.

Background: Determine TB-LAM is a urine-based point-of-care assay for diagnosis of tuberculosis (TB). Objective: To assess the feasibility of using LAM to diagnose TB in adult HIV-positive patients in resource-limited settings. Methods: We performed a multi-centric mixed-methods cross-sectional descriptive study in the Democratic Republic of Congo, Malawi, and Mozambique. We used the study and program monitoring tools to estimate user workload, turn-around time (TAT), and proportion of patients with LAM and sputum-based results. We conducted semi-structured interviews to assess the user acceptability of the LAM. Results: The duration of the LAM testing activity per patient was 27 min (IQR 26-29); staff continued with other duties whilst waiting for the result. More patients had a LAM versus a sputum-based result: 168/213 (78.9%) vs 77/213 (36.1%), p < 0.001 in DRC; 691/695 (99.4%) vs 429/695 (61.7%), p < 0.001 in Malawi; and 646/647 (99.8%) vs 262/647 (40.5%), p < 0.001 in Mozambique. The median TAT in minutes when LAM was performed in the consultation room was 75 (IQR 45-188) in DRC, 29 (IQR 27-39) in Malawi, and 36 (IQR 35-41) in Mozambique. In comparison, the overall median TAT for sputum-based tests (smear or GeneXpert) was 2 (IQR 1-3) days. The median time to the first anti-TB drug dose for LAM-positive patients was 155 (IQR 90-504) minutes in DRC and 90 (IQR 60-117) minutes in Mozambique. The overall inter-reader agreement for the interpretation of the LAM result as positive or negative was 98.9%, kappa 0.97 (95%CI 0.96-0.99). Overall, LAM users found the test easy to perform. Major concerns were use of the reading card and the prior requirement of CD4 results before LAM testing. Conclusion: It is feasible to implement the LAM test in low resource settings. The short TAT permitted same day initiation of TB treatment for LAM-positive patients.

Performance of Cepheid Xpert HIV-1 viral load plasma assay to accurately detect treatment failure.

BACKGROUND: Coverage of viral load testing remains low with only half of the patients in need having adequate access. Alternative technologies to high throughput centralized machines can be used to support viral load scale-up; however, clinical performance data are lacking. We conducted a meta-analysis comparing the Cepheid Xpert HIV-1 viral load plasma assay to traditional laboratory-based technologies. METHODS: Cepheid Xpert HIV-1 and comparator laboratory technology plasma viral load results were provided from 13 of the 19 eligible studies, which accounted for a total of 3790 paired data points. We used random effects models to determine the accuracy and misclassification at various treatment failure thresholds (detectable, 200, 400, 500, 600, 800 and 1000 copies/ml). RESULTS: Thirty percent of viral load test results were undetectable, while 45% were between detectable and 10 000 copies/ml and the remaining 25% were above 10 000 copies/ml. The median Xpert viral load was 119 copies/ml and the median comparator viral load was 157 copies/ml, while the log10 bias was 0.04 (0.02-0.07). The sensitivity and specificity to detect treatment failure were above 95% at all treatment failure thresholds, except for detectable, at which the sensitivity was 93.33% (95% confidence interval: 88.2-96.3) and specificity was 80.56% (95% CI: 64.6-90.4). CONCLUSION: The Cepheid Xpert HIV-1 viral load plasma assay results were highly comparable to laboratory-based technologies with limited bias and high sensitivity and specificity to detect treatment failure. Alternative specimen types and technologies that enable decentralized testing services can be considered to expand access to viral load.

Patient and health-care worker experiences of an HIV viral load intervention using SMS: A qualitative study.

BACKGROUND: Mobile Health or mHealth interventions, including Short Message Service (SMS), can help increase access to care, enhance the efficiency of health service delivery and improve diagnosis and treatment for HIV. Text messaging, or SMS, allows for the low cost transmission of information, and has been used to send appointment reminders, information about HIV counselling and treatment, messages to encourage adherence and information on nutrition and side-effects. HIV Viral Load (VL) monitoring is recommended by the WHO and has been progressively adopted in many settings. In Zimbabwe, implementation of VL is routine and has been rolled out with support of Médecins Sans Frontières (MSF) since 2012. An SMS intervention to assist with the management of VL results was introduced in two rural districts of Zimbabwe. After completion of the HIV VL testing at the National Microbiology Reference Laboratory in Harare, results were sent to health facilities via SMS. Consenting patients were also sent an SMS informing them that their viral load results were ready for collection at their nearest health facilities. No actual VL results were sent to patients. METHODS: A qualitative study was conducted in seven health-care facilities using in-depth interviews (n = 32) and focus group discussions (n = 5) to explore patient and health-care worker experiences of the SMS intervention. Purposive sampling was used to select participants to ensure that male and female patients, as well as those with differing VL results and who lived differing distances from the clinics were included. Data were transcribed, translated from Shona into English, coded and thematically analysed using NVivo software. RESULTS: The VL SMS intervention was considered acceptable to patients and health-care workers despite some challenges in implementation. The intervention was perceived by health-care workers as improving adherence and well-being of patients as well as improving the management of VL results at health facilities. However, there were some concerns from participants about the intervention, including challenges in understanding the purpose and language of the messages and patients coming to their health facility unnecessarily. Health-care workers were more concerned than patients about unintentional HIV disclosure relating to the content of the messages or phone-sharing. CONCLUSION: This was an innovative intervention in Zimbabwe, in which SMS was used to send VL results to health-care facilities, and notifications of the availability of VL results to patients. Interventions such as this have the potential to reduce unnecessary clinic visits and ensure patients with high VL results receive timely support, but they need to be properly explained, alongside routine counselling, for patients to fully benefit. The findings of this study also have potential policy implications, as if implemented well, such an SMS intervention has the potential to help patients adopt a more active role in the self-management of their HIV disease, become more aware of the importance of adherence and VL monitoring and seek follow-up at clinics when results are high.

Multidisease testing for HIV and TB using the GeneXpert platform: A feasibility study in rural Zimbabwe.

BACKGROUND: HIV Viral Load and Early Infant Diagnosis technologies in many high burden settings are restricted to centralized laboratory testing, leading to long result turnaround times and patient attrition. GeneXpert (Cepheid, CA, USA) is a polyvalent near point-of-care platform and is widely implemented for Xpert MTB/RIF diagnosis. This study sought to evaluate the operational feasibility of integrated HIV VL, EID and MTB/RIF testing in new GeneXpert platforms. METHODS: Whole blood samples were collected from consenting patients due for routine HIV VL testing and DBS samples from infants due for EID testing, at three rural health facilities in Zimbabwe. Sputum samples were collected from all individuals suspected of TB. GeneXpert testing was reserved for all EID, all TB suspects and priority HIV VL at each site. Blood samples were further sent to centralized laboratories for confirmatory testing. GeneXpert polyvalent testing results and patient outcomes, including infrastructural and logistical requirements are reported. The study was conducted over a 10-month period. RESULTS: The fully automated GeneXpert testing device, required minimal training and biosafety considerations. A total of 1,302 HIV VL, 277 EID and 1,581 MTB/RIF samples were tested on a four module GeneXpert platform in each study site. Xpert HIV-1 VL testing was prioritized for patients who presented with advanced HIV disease, pregnant women, adolescents and suspected ART failures patients. On average, the study sites had a GeneXpert utilization rate of 50.4% (Gutu Mission Hospital), 63.5% (Murambinda Mission Hospital) and 17.5% (Chimombe Rural Health Centre) per month. GeneXpert polyvalent testing error rates remained lower than 4% in all sites. Decentralized EID and VL testing on Xpert had shorter overall median TAT (1 day [IQR: 0-4] and 1 day [IQR: 0-1] respectively) compared to centralized testing (17 days [IQR: 13-21] and 26 days [IQR: 23-32] respectively). Among patients with VL >1000 copies/ml (73/640; 11.4%) at GMH health facility, median time to enhanced adherence counselling was 8 days and majority of those with documented outcomes had re-suppressed VL (20/32; 62.5%). Median time to ART initiation among Xpert EID positive infants at GMH was 1 day [IQR: 0-1]. CONCLUSION: Implementation of near point-of-care GeneXpert platform for integrated multi-disease testing within district and sub-district healthcare settings is feasible and will increase access to VL, and EID testing to priority populations. Quality management systems including monitoring of performance indicators, together with regular on-site supervision are crucial, and near-POC test results must be promptly actioned-on by clinicians for patient management.

Incidence and predictors of recovery from anaemia within an HIV-infected South African Cohort, 2004-2010.

INTRODUCTION: Anaemia is one of the most frequent haematological complications in HIV-infected persons. Understandingfactors associated with recovery from anaemia during ART is vital in improving clinical outcomes since anaemia is a strong predictor of mortality. METHODS: Cohort study of 12,441 HIV-infected adults initiating ART between 2004-2010 in Johannesburg, South Africa. A further 2,489 patients with prevalent anaemia at ART initiation were examined to determine the incidence and predictors of recovery from anaemia. Cox proportional hazards models were fitted to investigate predictors of recovery from anaemia. RESULTS: Of the 2,489 patients with prevalent anaemia, most patients (n=2,225, 89.4%) recovered from anaemia. Median time to anaemia recoverywas 3.9 months (IQR: 3.22-6.20) and incidence rate was 180 per 100person years (95% CI: 172-187). In univariateanalysis, sex, CD4 count, BMI, WHO stage, employment status, smoking status and presence of tuberculosis at initiation ofART were significant predictors of recovery from anaemia. However in multivariateanalysis, predictors of recovery from anaemia were: male sex-HR: 1.43 (95% CI: 1.29-1.59) p<0.001, advanced WHO stage III/IV-HR: 1.17 (95% CI: 1.07-1.29) p=0.001). There was no significant association with CD4 count in multivariate analysis. CONCLUSION: A large proportion of HIV infected patients with anaemia at baseline recover early during the course of ART. Females and those with less advanced WHO stage seem to be at higher risk of poor recovery from anaemia. Understanding the predictors for poor recovery from anaemia would allow closer follow-up and more targeted interventions thus reducing excess anaemia and mortality burden.