41 research outputs found
Improving access to new diagnostics through harmonised regulation: priorities for action.
A new generation of diagnostic tests is being developed for use at the point of care that could save lives and reduce the spread of infectious diseases through early detection and treatment. It is important that patients in developing countries have access to these products at affordable prices and without delay. Regulation of medical products is intended to ensure safety and quality whilst balancing the need for timely access to beneficial new products. Current regulatory oversight of diagnostic tests in developing countries is highly variable and weak regulation allows poor-quality tests to enter the market. However, inefficient or overzealous regulation results in unnecessary delays, increases costs and acts as a barrier to innovation and market entry. Setting international standards and streamlining the regulatory process could reduce these barriers. Four priority activities have been identified where convergence of standards and protocols or joint review of data would be advantageous: (1) adoption of a common registration file for pre-market approval; (2) convergence of quality standards for manufacturing site inspections; (3) use of common evaluation protocols, as well as joint review of data, to reduce unnecessary duplication of lengthy and costly clinical performance studies; and (4) use of networks of laboratories for post-market surveillance in order to monitor ongoing quality of diagnostic devices. The adoption and implementation of such measures in developing countries could accelerate access to new diagnostic tests that are safe and affordable
The costs of accessible quality assured syphilis diagnostics: informing quality systems for rapid syphilis tests in a Tanzanian setting.
OBJECTIVES: To determine the costs of Rapid Syphilis Test (RSTs) as compared with rapid plasma reagin (RPR) when implemented in a Tanzanian setting, and to determine the relative impact of a quality assurance (QA) system on the cost of RST implementation. METHODS: The incremental costs for RPR and RST screening programmes in existing antenatal care settings in Geita District, Tanzania were collected for 9 months in subsequent years from nine health facilities that varied in size, remoteness and scope of antenatal services. The costs per woman tested and treated were estimated for each facility. A sensitivity analysis was constructed to determine the impact of parameter and model uncertainty. FINDINGS: In surveyed facilities, a total of 6362 women were tested with RSTs compared with 224 tested with RPR. The range of unit costs was 3.13 per woman screened and 32.67 per woman treated. Unit costs for the QA system came to $0.51 per woman tested, of which 50% were attributed to salaries and transport for project personnel. CONCLUSIONS: Our results suggest that rapid syphilis diagnostics are very inexpensive in this setting and can overcome some critical barriers to ensuring universal access to syphilis testing and treatment. The additional costs for implementation of a quality system were found to be relatively small, and could be reduced through alterations to the programme design. Given the potential for a quality system to improve quality of diagnosis and care, we recommend that QA activities be incorporated into RST roll-out
Systematic review of the performance of HIV viral load technologies on plasma samples.
BACKGROUND: Viral load (VL) monitoring is the standard of care in developing country settings for detecting HIV treatment failure. Since 2010 the World Health Organization has recommended a phase-in approach to VL monitoring in resource-limited settings. We conducted a systematic review of the accuracy and precision of HIV VL technologies for treatment monitoring. METHODS AND FINDINGS: A search of Medline and Embase was conducted for studies evaluating the accuracy or reproducibility of commercially available HIV VL assays. 37 studies were included for review including evaluations of the Amplicor Monitor HIV-1 v1.5 (n = 25), Cobas TaqMan v2.0 (n = 11), Abbott RealTime HIV-1 (n = 23), Versant HIV-1 RNA bDNA 3.0 (n = 15), Versant HIV-1 RNA kPCR 1.0 (n = 2), ExaVir Load v3 (n = 2), and NucliSens EasyQ v2.0 (n = 1). All currently available HIV VL assays are of sufficient sensitivity to detect plasma virus levels at a lower detection limit of 1,000 copies/mL. Bias data comparing the Abbott RealTime HIV-1, TaqMan v2.0 to the Amplicor Monitor v1.5 showed a tendency of the Abbott RealTime HIV-1 to under-estimate results while the TaqMan v2.0 overestimated VL counts. Compared to the Amplicor Monitor v1.5, 2-26% and 9-70% of results from the Versant bDNA 3.0 and Abbott RealTime HIV-1 differed by greater than 0.5log10. The average intra and inter-assay variation of the Abbott RealTime HIV-1 were 2.95% (range 2.0-5.1%) and 5.44% (range 1.17-30.00%) across the range of VL counts (2log10-7log10). CONCLUSIONS: This review found that all currently available HIV VL assays are of sufficient sensitivity to detect plasma VL of 1,000 copies/mL as a threshold to initiate investigations of treatment adherence or possible treatment failure. Sources of variability between VL assays include differences in technology platform, plasma input volume, and ability to detect HIV-1 subtypes. Monitoring of individual patients should be performed on the same technology platform to ensure appropriate interpretation of changes in VL. Prospero registration # CD42013003603
Regulation of medical diagnostics and medical devices in the East African community partner states.
BACKGROUND: Medical devices and in vitro diagnostic tests (IVD) are vital components of health delivery systems but access to these important tools is often limited in Africa. The regulation of health commodities by National Regulatory Authorities is intended to ensure their safety and quality whilst ensuring timely access to beneficial new products. Streamlining and harmonizing regulatory processes may reduce delays and unnecessary expense and improve access to new products. Whereas pharmaceutical products are widely regulated less attention has been placed on the regulation of other health products. A study was undertaken to assess regulation of medical diagnostics and medical devices across Partner States of the East African Community (EAC). METHODS: Data was collected during October 2012 through desk based review of documents and field research, including face to face interviews with the assistance of a structured questionnaire with closed and open ended questions. Key areas addressed were (i) existence and role of National Regulatory Authorities; (ii) policy and legal framework for regulation; (iii) premarket control; (iv) marketing controls; (v) post-marketing control and vigilance; (vi) country capacity for regulation; (vii) country capacity for evaluation studies for IVD and (viii) priorities and capacity building for harmonization in EAC Partner States. RESULTS: Control of medical devices and IVDs in EAC Partner States is largely confined to national disease programmes such as tuberculosis, HIV and malaria. National Regulatory Authorities for pharmaceutical products do not have the capacity to regulate medical devices and in some countries laboratory based organisations are mandated to ensure quality of products used. Some activities to evaluate IVDs are performed in research laboratories but post market surveillance is rare. Training in key areas is considered essential to strengthening regulatory capacity for IVDs and other medical devices. CONCLUSIONS: Regulation of medical devices and in vitro diagnostics has been neglected in EAC Partner States. Regulation is weak across the region, and although the majority of States have a legal mandate to regulate medical devices there is limited capacity to do so. Streamlining regulation in the EAC is seen as a positive aspiration with diagnostic tests considered a priority area for harmonisation
Systematic review of the use of dried blood spots for monitoring HIV viral load and for early infant diagnosis.
BACKGROUND: Dried blood spots (DBS) have been used as alternative specimens to plasma to increase access to HIV viral load (VL) monitoring and early infant diagnosis (EID) in remote settings. We systematically reviewed evidence on the performance of DBS compared to plasma for VL monitoring and EID. METHODS AND FINDINGS: Thirteen peer reviewed HIV VL publications and five HIV EID papers were included. Depending on the technology and the viral load distribution in the study population, the percentage of DBS samples that are within 0.5 log of VL in plasma ranged from 52-100%. Because the input sample volume is much smaller in a blood spot, there is a risk of false negatives with DBS. Sensitivity of DBS VL was found to be 78-100% compared to plasma at VL below 1000 copies/ml, but this increased to 100% at a threshold of 5000 copies/ml. Unlike a plasma VL test which measures only cell free HIV RNA, a DBS VL also measures proviral DNA as well as cell-associated RNA, potentially leading to false positive results when using DBS. The systematic review showed that specificity was close to 100% at DBS VL above 5000 copies/ml, and this threshold would be the most reliable for predicting true virologic failure using DBS. For early infant diagnosis, DBS has a sensitivity of 100% compared to fresh whole blood or plasma in all studies. CONCLUSIONS: Although limited data are available for EID, DBS offer a highly sensitive and specific sampling strategy to make viral load monitoring and early infant diagnosis more accessible in remote settings. A standardized approach for sampling, storing, and processing DBS samples would be essential to allow successful implementation. TRIAL REGISTRATION: PROSPERO Registration #: CRD42013003621
Point-of-Care Tests to Strengthen Health Systems and Save Newborn Lives: The Case of Syphilis
Rosanna Peeling and colleagues describe their experience of introducing point-of-care testing to screen for syphilis in pregnant women living in low- and middle-income countries
External quality assurance with dried tube specimens (DTS) for point-of-care syphilis and HIV tests: experience in an indigenous populations screening programme in the Brazilian Amazon.
OBJECTIVES: The availability of point-of-care (POC) tests for infectious diseases has revolutionised the provision of healthcare for remote rural populations without access to laboratories. However, quality assurance for POC tests has been largely overlooked. We have evaluated the use and stability of dry tube specimens (DTS) for External Quality Assurance (EQA) for HIV and syphilis screening in remote indigenous populations in the Amazon region of Brazil. METHODS: All healthcare workers (HCWs) participating in the community-screening were trained. We used HIV and syphilis DTS panels developed by the reference laboratory, containing samples with negative and positive results at different antibody concentrations, for both infections. DTS panels were distributed to HCWs in the communities for reconstitution and testing using POC HIV and syphilis tests. The results of testing were sent to the reference laboratory for marking and remedial action taken where necessary. RESULTS: In total 268 HCWs tested 1607 samples for syphilis and 1608 samples for HIV. Results from HCWs showed a concordance rate of 90% for syphilis and 93% for HIV (κ coefficients of 0.74 and 0.78, respectively) with reference laboratories. Most false negatives were in samples of very low antibody concentration. DTS syphilis specimens produced the expected results after storage at 2-8°C or at 18-24°C for up to 3 weeks. CONCLUSIONS: The results show that POC tests for syphilis and HIV give valid results in environments where traditional tests do not work, but errors in the interpretation of POC test results were identified by the EQA programme using DTS. EQA using DTS can help to improve the quality of screening programmes using POC tests in remote regions
Research-based practice Resolving care problems
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Bias between Index Test and Ampicor v1.5 as a comparator (data extracted from references [19], [24], [25], [29], [37], [38], [40], [41], [43], [45], [46], [48], [52], [55]). *No volume specified.
<p>Bias between Index Test and Ampicor v1.5 as a comparator (data extracted from references <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085869#pone.0085869-Braun1" target="_blank">[19]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085869#pone.0085869-Damond1" target="_blank">[24]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085869#pone.0085869-Do1" target="_blank">[25]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085869#pone.0085869-Gueudin1" target="_blank">[29]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085869#pone.0085869-Poveda1" target="_blank">[37]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085869#pone.0085869-Pyne1" target="_blank">[38]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085869#pone.0085869-Schutten1" target="_blank">[40]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085869#pone.0085869-Scott1" target="_blank">[41]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085869#pone.0085869-Sivapalasingam1" target="_blank">[43]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085869#pone.0085869-Sloma1" target="_blank">[45]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085869#pone.0085869-Ssebugenyi1" target="_blank">[46]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085869#pone.0085869-Swanson1" target="_blank">[48]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085869#pone.0085869-Weissman1" target="_blank">[52]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085869#pone.0085869-Young1" target="_blank">[55]</a>). *No volume specified.</p