Conference Material > Poster
Niykayo LF, Mahajan R, Sagrado MJ, Ajack YBP, Chol BT, et al.
MSF Paediatric Days 2024. 2024 May 3; DOI:10.57740/CO9XKuY
Conference Material > Video (talk)
Moreto-Planas L, Sagrado MJ, Mahajan R, Gallo J, Biague E, et al.
MSF Scientific Days International 2022. 2022 June 7; DOI:10.57740/50a1-ba02
Conference Material > Poster
Abdullah N, Ameen T, Albdulwasa'a R, Alkholidy GC, Shoaib M
MSF Paediatric Days 2022. 2022 November 29; DOI:10.57740/ayzy-ej78
Journal Article > Review
Lab Chip. 2021 December 31; Volume 22 (Issue 17); 3122-3137.; DOI:10.1039/d2lc00380e
Ongaro AE, Ndlovu Z, Sollier E, Otieno C, Ondoa P, et al.
Lab Chip. 2021 December 31; Volume 22 (Issue 17); 3122-3137.; DOI:10.1039/d2lc00380e
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.
Journal Article > ResearchFull Text
Public Health Action. 2024 March 1; Volume 14 (Issue 1); 14-19.; DOI:10.5588/pha.23.0022
Tsorou C, Williams A, van den Boogaard W, Staderini N, Repetto E, et al.
Public Health Action. 2024 March 1; Volume 14 (Issue 1); 14-19.; DOI:10.5588/pha.23.0022
SETTING
Sexually transmitted infections (STIs) can impact individuals of any demographic. The most common pathogens causing STIs are Chlamydia trachomatis, Neisseria gonorrhea and Trichomonas vaginalis; these can be treated with specific antibiotics.
OBJECTIVE
To compare the GeneXpert CT/NG test-and-treat algorithm to the syndromic approach algorithm and their impact on antibiotic prescription for gonorrhoea and chlamydia STIs.
DESIGN
A retrospective observational study on women aged ≥18 years who accessed the Médecins Sans Frontières Day Care Centre in Athens with complaints related to urogenital infections between January 2021 and March 2022. Women with abnormal vaginal discharge, excluding clinically diagnosed candidiasis, were eligible for Xpert CT/NG testing.
RESULTS
Of the 450 women who accessed care, 84 were eligible for Xpert CT/NG testing, and only one was positive for chlamydia, therefore resulting in saving 81 doses of ceftriaxone and azithromycin, and 19 doses of metronidazole. The cost of Xpert CT/NG testing, including treatment was €4,606.37, while full antibiotic treatment would have costed €536.76.
CONCLUSION
The overall cost of the Xpert CT/NG test-and-treat algorithm was higher than the syndromic approach. However, quality of care should be weighed against the potential benefits of testing and syndromic treatment to determine the best option for each patient; we therefore advocate for decreasing the costs.
Sexually transmitted infections (STIs) can impact individuals of any demographic. The most common pathogens causing STIs are Chlamydia trachomatis, Neisseria gonorrhea and Trichomonas vaginalis; these can be treated with specific antibiotics.
OBJECTIVE
To compare the GeneXpert CT/NG test-and-treat algorithm to the syndromic approach algorithm and their impact on antibiotic prescription for gonorrhoea and chlamydia STIs.
DESIGN
A retrospective observational study on women aged ≥18 years who accessed the Médecins Sans Frontières Day Care Centre in Athens with complaints related to urogenital infections between January 2021 and March 2022. Women with abnormal vaginal discharge, excluding clinically diagnosed candidiasis, were eligible for Xpert CT/NG testing.
RESULTS
Of the 450 women who accessed care, 84 were eligible for Xpert CT/NG testing, and only one was positive for chlamydia, therefore resulting in saving 81 doses of ceftriaxone and azithromycin, and 19 doses of metronidazole. The cost of Xpert CT/NG testing, including treatment was €4,606.37, while full antibiotic treatment would have costed €536.76.
CONCLUSION
The overall cost of the Xpert CT/NG test-and-treat algorithm was higher than the syndromic approach. However, quality of care should be weighed against the potential benefits of testing and syndromic treatment to determine the best option for each patient; we therefore advocate for decreasing the costs.
Journal Article > ResearchFull Text
PLOS One. 2017 July 27; Volume 12 (Issue 7); e0182005.; DOI:10.1371/journal.pone.0182005
Rasti R, Nanjebe D, Karlstrom J, Muchunguzi C, Mwanga-Amumpaire J, et al.
PLOS One. 2017 July 27; Volume 12 (Issue 7); e0182005.; DOI:10.1371/journal.pone.0182005
Point-of-care (POC) tests have become increasingly available and more widely used in recent years. They have been of particular importance to low-income settings, enabling them with clinical capacities that had previously been limited. POC testing programs hold a great potential for significant improvement in low-income health systems. However, as most POC tests are developed in high-income countries, disengagement between developers and end-users inhibit their full potential. This study explores perceptions of POC test end-users in a low-income setting, aiming to support the development of novel POC tests for low-income countries.
Journal Article > ResearchFull Text
PLOS Glob Public Health. 2023 March 27; Volume 3 (Issue 3); e0001678.; DOI:10.1371/journal.pgph.0001678
Boyce RM, Ndizeye R, Ngelese H, Baguma E, Shem B, et al.
PLOS Glob Public Health. 2023 March 27; Volume 3 (Issue 3); e0001678.; DOI:10.1371/journal.pgph.0001678
Barriers continue to limit access to viral load (VL) monitoring across sub-Saharan Africa adversely impacting control of the HIV epidemic. The objective of this study was to determine whether the systems and processes required to realize the potential of rapid molecular technology are available at a prototypical lower-level (i.e., level III) health center in rural Uganda. In this open-label pilot study, participants underwent parallel VL testing at both the central laboratory (i.e., standard of care) and on-site using the GeneXpert HIV-1 assay. The primary outcome was the number of VL tests completed each clinic day. Secondary outcomes included the number of days from sample collection to receipt of result at clinic and the number of days from sample collection to patient receipt of the result. From August 2020 to July 2021, we enrolled a total of 242 participants. The median number of daily tests performed on the Xpert platform was 4, (IQR = 2–7). Time from sample collection to result was 51 days (IQR = 45–62) for samples sent to the central laboratory and 0 days (IQR = 0–0.25) for the Xpert assay conducted at the health center. However, few participants elected to receive results by one of the expedited options, which contributed to similar time-to-patient between testing approaches (89 versus 84 days, p = 0.07). Implementation of a rapid, near point-of-care VL assay at a lower-level health center in rural Uganda appears feasible, but interventions to promote rapid clinical response and influence patient preferences about result receipt require further study.
Journal Article > ResearchFull Text
BMC Infect Dis. 2024 March 4; Volume 24 (Issue S1); 277.; DOI:10.1186/s12879-024-09018-4
Shephard M, Matthews S, Kularatne R, Andrewartha K, Blondeel K, et al.
BMC Infect Dis. 2024 March 4; Volume 24 (Issue S1); 277.; DOI:10.1186/s12879-024-09018-4
BACKGROUND
In 2018, the World Health Organization commenced a multi-country validation study of the Cepheid GeneXpert for a range of molecular-based point-of-care (POC) tests in primary care settings. One study arm focused on the evaluation of POC tests for screening ‘women at risk’ for chlamydia (CT), gonorrhoea (NG) and trichomonas (TV) in four countries – Australia, Guatemala, Morocco and South Africa.
METHODS
Study participants completed a pre-test questionnaire which included demographics, clinical information and general questions on POC testing (POCT). Two vaginal swab samples (either self-collected or clinician collected) from each patient were tested on the GeneXpert at the POC and at a reference laboratory using quality-assured nucleic acid amplification tests (NAATs).
RESULTS
One thousand three hundred and eighty-three women were enrolled: 58.6% from South Africa, 29.2% from Morocco, 6.2% from Guatemala, and 6.0% from Australia. 1,296 samples for CT/NG and 1,380 samples for TV were tested by the GeneXpert and the reference NAAT. The rate of unsuccessful tests on the GeneXpert was 1.9% for CT, 1.5% for NG and 0.96% for TV. The prevalence of CT, NG and TV was 31%, 13% and 23%, respectively. 1.5% of samples were positive for all three infections; 7.8% were positive for CT and NG; 2.4% were positive for NG and TV; and 7.3% were positive for CT and TV. Compared to reference NAATs, pooled estimates of sensitivity for the GeneXpert tests were 83.7% (95% confidence intervals 69.2-92.1) for CT, 90.5% (85.1-94.1) for NG and 64.7% (58.1-70.7) for TV (although estimates varied considerably between countries). Estimates for specificity were ≥96% for all three tests both within- and between-countries. Pooled positive and negative likelihood ratios were: 32.7 ([CI] 21.2-50.5) and 0.17 (0.08-0.33) for CT; 95.3 (36.9-245.7) and 0.10 (0.06-0.15) for NG; and 56.5 (31.6-101.1) and 0.35 (0.27-0.47) for TV.
CONCLUSION
This multi-country evaluation is the first of its kind world-wide. Positive likelihood ratios, as well as specificity estimates, indicate the GeneXpert POC test results for CT, NG and TV were clinically acceptable for ruling in the presence of disease. However, negative likelihood ratios and variable sensitivity estimates from this study were poorer than expected for ruling out these infections, particularly for TV.
In 2018, the World Health Organization commenced a multi-country validation study of the Cepheid GeneXpert for a range of molecular-based point-of-care (POC) tests in primary care settings. One study arm focused on the evaluation of POC tests for screening ‘women at risk’ for chlamydia (CT), gonorrhoea (NG) and trichomonas (TV) in four countries – Australia, Guatemala, Morocco and South Africa.
METHODS
Study participants completed a pre-test questionnaire which included demographics, clinical information and general questions on POC testing (POCT). Two vaginal swab samples (either self-collected or clinician collected) from each patient were tested on the GeneXpert at the POC and at a reference laboratory using quality-assured nucleic acid amplification tests (NAATs).
RESULTS
One thousand three hundred and eighty-three women were enrolled: 58.6% from South Africa, 29.2% from Morocco, 6.2% from Guatemala, and 6.0% from Australia. 1,296 samples for CT/NG and 1,380 samples for TV were tested by the GeneXpert and the reference NAAT. The rate of unsuccessful tests on the GeneXpert was 1.9% for CT, 1.5% for NG and 0.96% for TV. The prevalence of CT, NG and TV was 31%, 13% and 23%, respectively. 1.5% of samples were positive for all three infections; 7.8% were positive for CT and NG; 2.4% were positive for NG and TV; and 7.3% were positive for CT and TV. Compared to reference NAATs, pooled estimates of sensitivity for the GeneXpert tests were 83.7% (95% confidence intervals 69.2-92.1) for CT, 90.5% (85.1-94.1) for NG and 64.7% (58.1-70.7) for TV (although estimates varied considerably between countries). Estimates for specificity were ≥96% for all three tests both within- and between-countries. Pooled positive and negative likelihood ratios were: 32.7 ([CI] 21.2-50.5) and 0.17 (0.08-0.33) for CT; 95.3 (36.9-245.7) and 0.10 (0.06-0.15) for NG; and 56.5 (31.6-101.1) and 0.35 (0.27-0.47) for TV.
CONCLUSION
This multi-country evaluation is the first of its kind world-wide. Positive likelihood ratios, as well as specificity estimates, indicate the GeneXpert POC test results for CT, NG and TV were clinically acceptable for ruling in the presence of disease. However, negative likelihood ratios and variable sensitivity estimates from this study were poorer than expected for ruling out these infections, particularly for TV.
Conference Material > Poster
Phillip E, Adede J, Onduto S, Ochola C, Simba R, et al.
MSF Paediatric Days 2024. 2024 May 3; DOI:10.57740/w8leOu
Journal Article > ResearchFull Text
Lancet Infect Dis. 2024 September 1; Volume 24 (Issue 9); 1037-1044.; DOI:10.1016/S1473-3099(24)00184-1
Elsinga J, Sunyoto T, di Stefano L, Giorgetti PF, Kyi HA, et al.
Lancet Infect Dis. 2024 September 1; Volume 24 (Issue 9); 1037-1044.; DOI:10.1016/S1473-3099(24)00184-1
BACKGROUND
Lassa fever is a viral haemorrhagic fever with few options for diagnosis and treatment; it is also under-researched with knowledge gaps on its epidemiology. A point-of-care bedside test diagnosing Lassa fever, adhering to REASSURED criteria, is not currently available but is urgently needed in west African regions with high Lassa fever burden. We aimed to assess the validity and feasibility of a rapid diagnostic test (RDT) to confirm Lassa fever in people in Nigeria.
METHODS
We estimated the diagnostic performance of the ReLASV Pan-Lassa RDT (Zalgen Labs, Frederick, MD, USA) as a research-use-only test, compared to RT-PCR as a reference standard, in 217 participants at a federal tertiary hospital in Abakaliki, Nigeria. We recruited participants between Feb 17, 2022, and April 17, 2023. The RDT was performed using capillary blood at the patient bedside and using plasma at the laboratory. The performance of the test, based on REASSURED criteria, was assessed for user friendliness, rapidity and robustness, sensitivity, and specificity.
FINDINGS
Participants were aged between 0 and 85 years, with a median age of 33·0 years (IQR 22·0-44·3), and 24 participants were younger than 18 years. 107 (50%) participants were women and 109 (50%) were men; one participant had missing sex data. Although the specificity of the Pan-Lassa RDT was high (>90%), sensitivity at bedside using capillary blood was estimated as 4% (95% CI 1-14) at 15 min and 10% (3-22) at 25 min, far below the target of 90%. The laboratory-based RDT using plasma showed better sensitivity (46% [32-61] at 15 min and 50% [36-64] at 25 min) but did not reach the target sensitivity. Among the 52 PCR-positive participants with Lassa fever, positive RDT results were associated with lower cycle threshold values (glycoprotein precursor [GPC] gene mean 30·3 [SD 4·3], Large [L] gene mean 32·3 [3·7] vs GPC gene mean 24·5 [3·9], L gene mean 28·0 [3·6]). Personnel conducting the bedside test procedure reported being hindered by the inconvenient use of full personal protective equipment and long waiting procedures before a result could be read.
INTERPRETATION
The Pan-Lassa RDT is not currently recommended as a diagnostic or screening tool for suspected Lassa fever cases. Marked improvement in sensitivity and user friendliness is needed for the RDT to be adopted clinically. There remains an urgent need for better Lassa fever diagnostics to promote safety of in-hospital care and better disease outcomes in low-resource settings.
Lassa fever is a viral haemorrhagic fever with few options for diagnosis and treatment; it is also under-researched with knowledge gaps on its epidemiology. A point-of-care bedside test diagnosing Lassa fever, adhering to REASSURED criteria, is not currently available but is urgently needed in west African regions with high Lassa fever burden. We aimed to assess the validity and feasibility of a rapid diagnostic test (RDT) to confirm Lassa fever in people in Nigeria.
METHODS
We estimated the diagnostic performance of the ReLASV Pan-Lassa RDT (Zalgen Labs, Frederick, MD, USA) as a research-use-only test, compared to RT-PCR as a reference standard, in 217 participants at a federal tertiary hospital in Abakaliki, Nigeria. We recruited participants between Feb 17, 2022, and April 17, 2023. The RDT was performed using capillary blood at the patient bedside and using plasma at the laboratory. The performance of the test, based on REASSURED criteria, was assessed for user friendliness, rapidity and robustness, sensitivity, and specificity.
FINDINGS
Participants were aged between 0 and 85 years, with a median age of 33·0 years (IQR 22·0-44·3), and 24 participants were younger than 18 years. 107 (50%) participants were women and 109 (50%) were men; one participant had missing sex data. Although the specificity of the Pan-Lassa RDT was high (>90%), sensitivity at bedside using capillary blood was estimated as 4% (95% CI 1-14) at 15 min and 10% (3-22) at 25 min, far below the target of 90%. The laboratory-based RDT using plasma showed better sensitivity (46% [32-61] at 15 min and 50% [36-64] at 25 min) but did not reach the target sensitivity. Among the 52 PCR-positive participants with Lassa fever, positive RDT results were associated with lower cycle threshold values (glycoprotein precursor [GPC] gene mean 30·3 [SD 4·3], Large [L] gene mean 32·3 [3·7] vs GPC gene mean 24·5 [3·9], L gene mean 28·0 [3·6]). Personnel conducting the bedside test procedure reported being hindered by the inconvenient use of full personal protective equipment and long waiting procedures before a result could be read.
INTERPRETATION
The Pan-Lassa RDT is not currently recommended as a diagnostic or screening tool for suspected Lassa fever cases. Marked improvement in sensitivity and user friendliness is needed for the RDT to be adopted clinically. There remains an urgent need for better Lassa fever diagnostics to promote safety of in-hospital care and better disease outcomes in low-resource settings.