Conference Material > Poster
Obach D, Fares K, Woolley SC, Jean-Louis C, Denis O, et al.
MSF Scientific Days International 2022. 2022 May 9; DOI:10.57740/t33d-2m41
Journal Article > ResearchFull Text
Bull World Health Organ. 2015 June 25; Volume 93 (Issue 9); 623-630.; DOI:10.2471/BLT.14.146480
Fajardo E, Metcalf CJ, Piriou E, Gueguen M, Maman D, et al.
Bull World Health Organ. 2015 June 25; Volume 93 (Issue 9); 623-630.; DOI:10.2471/BLT.14.146480
OBJECTIVE
To estimate the proportion of invalid results generated by a CD4+ T-lymphocyte analyser used by Médecins Sans Frontières (MSF) in field projects and identify factors associated with invalid results.
METHODS
We collated 25,616 CD4+ T-lymphocyte test results from 39 sites in nine countries for the years 2011 to 2013. Information about the setting, user, training, sampling technique and device repair history were obtained by questionnaire. The analyser performs a series of checks to ensure that all steps of the analysis are completed successfully; if not, an invalid result is reported. We calculated the proportion of invalid results by device and by operator. Regression analyses were used to investigate factors associated with invalid results.
FINDINGS
There were 3354 invalid test results (13.1%) across 39 sites, for 58 Alere PimaTM devices and 180 operators. The median proportion of errors per device and operator was 12.7% (interquartile range, IQR: 10.3-19.9) and 12.1% (IQR: 7.1-19.2), respectively. The proportion of invalid results varied widely by country, setting, user and device. Errors were not associated with settings, user experience or the number of users per device. Tests performed on capillary blood samples were significantly less likely to generate errors compared to venous whole blood.
CONCLUSION
The Alere Pima CD4+ analyser generated a high proportion of invalid test results, across different countries, settings and users. Most error codes could be attributed to the operator, but the exact causes proved difficult to identify. Invalid results need to be factored into the implementation and operational costs of routine CD4+ T-lymphocyte testing.
To estimate the proportion of invalid results generated by a CD4+ T-lymphocyte analyser used by Médecins Sans Frontières (MSF) in field projects and identify factors associated with invalid results.
METHODS
We collated 25,616 CD4+ T-lymphocyte test results from 39 sites in nine countries for the years 2011 to 2013. Information about the setting, user, training, sampling technique and device repair history were obtained by questionnaire. The analyser performs a series of checks to ensure that all steps of the analysis are completed successfully; if not, an invalid result is reported. We calculated the proportion of invalid results by device and by operator. Regression analyses were used to investigate factors associated with invalid results.
FINDINGS
There were 3354 invalid test results (13.1%) across 39 sites, for 58 Alere PimaTM devices and 180 operators. The median proportion of errors per device and operator was 12.7% (interquartile range, IQR: 10.3-19.9) and 12.1% (IQR: 7.1-19.2), respectively. The proportion of invalid results varied widely by country, setting, user and device. Errors were not associated with settings, user experience or the number of users per device. Tests performed on capillary blood samples were significantly less likely to generate errors compared to venous whole blood.
CONCLUSION
The Alere Pima CD4+ analyser generated a high proportion of invalid test results, across different countries, settings and users. Most error codes could be attributed to the operator, but the exact causes proved difficult to identify. Invalid results need to be factored into the implementation and operational costs of routine CD4+ T-lymphocyte testing.
Conference Material > Poster
Elsinga J, Sunyoto T, Di Stefano L, Giorgetti PF, Kyi HA, et al.
MSF Scientific Day International 2024. 2024 May 16; DOI:10.57740/63l6oZ
Journal Article > CommentaryFull Text
Trop Med Int Health. 2010 November 2; Volume 16 (Issue 1); DOI:10.1111/j.1365-3156.2010.02669.x
Zachariah R, Reid SE, Chaillet P, Massaquoi M, Schouten EJ, et al.
Trop Med Int Health. 2010 November 2; Volume 16 (Issue 1); DOI:10.1111/j.1365-3156.2010.02669.x
In this paper, we discuss the reasons why we urgently need a point-of-care (POC) CD4 test, elaborate the problems we have experienced with the current technology which hampers CD4-count coverage and highlight the ideal characteristics of a universal CD4 POC test. It is high-time that CD4 technology is simplified and adapted for wider use in low-income countries to change the current paradigm of restricted access once and for all.
Journal Article > CommentaryAbstract Only
Disaster Med Public Health Prep. 2019 June 24; Volume 13 (Issue 5-6); 1028-1034.; DOI:10.1017/dmp.2019.39
Williams A, Amand M, Van der Bergh R, Antierens A, Chaillet P
Disaster Med Public Health Prep. 2019 June 24; Volume 13 (Issue 5-6); 1028-1034.; DOI:10.1017/dmp.2019.39
The capacity to rapidly distinguish Ebola virus disease from other infectious diseases and to monitor biochemistry and viremia levels is crucial to the clinical management of suspected Ebola virus disease cases. This article describes the design and practical considerations of a laboratory straddling the high- and low-risk zones of an Ebola treatment center to produce timely diagnostic and clinical results for informed case management of Ebola virus disease in real-life conditions. This innovation may be of relevance for actors requiring flexible laboratory implementation in contexts of high-communicability, high-lethality disease outbreaks.
Journal Article > ResearchFull Text
BMC Pediatr. 2019 August 15; Volume 19 (Issue 1); DOI:10.1186/s12887-019-1622-4
Ogundipe OF, Van der Bergh R, Thierry B, Takarinda KC, Muller CP, et al.
BMC Pediatr. 2019 August 15; Volume 19 (Issue 1); DOI:10.1186/s12887-019-1622-4
BACKGROUND:
In high syphilis prevalence settings, the syphilis testing and treatment strategy for mothers and newborns must be tailored to balance the risk of over treatment against the risk of missing infants at high-risk for congenital syphilis. Adding a non-treponemal test (Rapid Plasma Reagin - RPR) to a routine rapid treponemal test (SD Bioline Syphilis 3.0) for women giving birth can help distinguish between neonates at high and low-risk for congenital syphilis to tailor their treatment. Treatment for neonates born to RPR-reactive mothers (high-risk) is 10 days of intravenous penicillin, while one dose of intramuscular penicillin is sufficient for those born to RPR non-reactive mothers (low-risk). This strategy was adopted in March 2017 in a Médecins Sans Frontières supported hospital in Bangui, Central African Republic. This study examined the operational consequences of this algorithm on the treatment of newborns.
METHODS:
The study was a retrospective cohort study. Routine programmatic data were analysed. Descriptive statistical analysis was done. Total antibiotic days, hospitalization days and estimated costs were compared to scenarios without RPR testing and another where syphilis treatment was the sole reason for hospitalization.
RESULTS:
Of 202 babies born to SD Bioline positive mothers 89 (44%) and 111(55%) were RPR-reactive and non-reactive respectively (2 were unrecorded) of whom 80% and 88% of the neonates received appropriate antibiotic treatment respectively. Neonates born to RPR non-reactive mothers were 80% less likely to have sepsis [Relative risk (RR) = 0.20; 95% Confidence interval (CI) = 0.04-0.92] and 9% more likely to be discharged [RR = 1.09; 95% CI = 1.00-1.18] compared to those of RPR-reactive mothers. There was a 52%, and 49% reduction in antibiotic and hospitalization days respectively compared to a scenario with SD-Bioline testing only. Total hospitalization costs were also 52% lower compared to a scenario without RPR testing.
CONCLUSIONS:
This testing strategy can help identify infants at high and low risk for congenital syphilis and treat them accordingly at substantial cost savings. It is especially appropriate for settings with high syphilis endemicity, limited resources and overcrowded maternities. The babies additionally benefit from lower risks of exposure to unnecessary antibiotics and nosocomial infections.
In high syphilis prevalence settings, the syphilis testing and treatment strategy for mothers and newborns must be tailored to balance the risk of over treatment against the risk of missing infants at high-risk for congenital syphilis. Adding a non-treponemal test (Rapid Plasma Reagin - RPR) to a routine rapid treponemal test (SD Bioline Syphilis 3.0) for women giving birth can help distinguish between neonates at high and low-risk for congenital syphilis to tailor their treatment. Treatment for neonates born to RPR-reactive mothers (high-risk) is 10 days of intravenous penicillin, while one dose of intramuscular penicillin is sufficient for those born to RPR non-reactive mothers (low-risk). This strategy was adopted in March 2017 in a Médecins Sans Frontières supported hospital in Bangui, Central African Republic. This study examined the operational consequences of this algorithm on the treatment of newborns.
METHODS:
The study was a retrospective cohort study. Routine programmatic data were analysed. Descriptive statistical analysis was done. Total antibiotic days, hospitalization days and estimated costs were compared to scenarios without RPR testing and another where syphilis treatment was the sole reason for hospitalization.
RESULTS:
Of 202 babies born to SD Bioline positive mothers 89 (44%) and 111(55%) were RPR-reactive and non-reactive respectively (2 were unrecorded) of whom 80% and 88% of the neonates received appropriate antibiotic treatment respectively. Neonates born to RPR non-reactive mothers were 80% less likely to have sepsis [Relative risk (RR) = 0.20; 95% Confidence interval (CI) = 0.04-0.92] and 9% more likely to be discharged [RR = 1.09; 95% CI = 1.00-1.18] compared to those of RPR-reactive mothers. There was a 52%, and 49% reduction in antibiotic and hospitalization days respectively compared to a scenario with SD-Bioline testing only. Total hospitalization costs were also 52% lower compared to a scenario without RPR testing.
CONCLUSIONS:
This testing strategy can help identify infants at high and low risk for congenital syphilis and treat them accordingly at substantial cost savings. It is especially appropriate for settings with high syphilis endemicity, limited resources and overcrowded maternities. The babies additionally benefit from lower risks of exposure to unnecessary antibiotics and nosocomial infections.
Journal Article > ReviewAbstract Only
Expert Rev Anti Infect Ther. 2016 May 13; Volume 14 (Issue 6); 557-567.; DOI:10.1080/14787210.2016.1176912
de la Vega MA, Bello A, Chaillet P, Kobinger GP
Expert Rev Anti Infect Ther. 2016 May 13; Volume 14 (Issue 6); 557-567.; DOI:10.1080/14787210.2016.1176912
The magnitude of the 2014–2016 West African Ebola virus outbreak has highlighted the importance of immediate and rapid deployment of control measures in affected areas. While many prophylactic and therapeutic options entered clinical trials in the past two years, larger use to impact on Ebola spread will not be possible until at least one product meets final approval by regulatory agencies. Control of the West African outbreak was achieved almost entirely by breaking chain of transmissions through case identification and specialized treatment, communication, safe burials and other proven methods. To achieve this in a timely manner, epidemiologists and medical teams are working in concert with laboratories to identify infected individuals and provide care within Ebola treatment units. Herein, we review an outbreak response workflow from the point of view of mobile laboratories and summarize methods that have been used by them during the West African Ebola virus outbreak of 2014–2016.
Journal Article > ResearchFull Text
Emerg Infect Dis. 2016 February 1; Volume 22 (Issue 2); DOI:10.3201/eid2202.151238
Van der Bergh R, Chaillet P, Sow MS, Amand M, van Vyve C, et al.
Emerg Infect Dis. 2016 February 1; Volume 22 (Issue 2); DOI:10.3201/eid2202.151238
Rapid diagnostic methods are essential in control of Ebola outbreaks and lead to timely isolation of cases and improved epidemiologic surveillance. Diagnosis during Ebola outbreaks in West Africa has relied on PCR performed in laboratories outside this region. Because time between sampling and PCR results can be considerable, we assessed the feasibility and added value of using the Xpert Ebola Assay in an Ebola control program in Guinea. A total of 218 samples were collected during diagnosis, treatment, and convalescence of patients. Median time for obtaining results was reduced from 334 min to 165 min. Twenty-six samples were positive for Ebola virus. Xpert cycle thresholds were consistently lower, and 8 (31%) samples were negative by routine PCR. Several logistic and safety issues were identified. We suggest that implementation of the Xpert Ebola Assay under programmatic conditions is feasible and represents a major advance in diagnosis of Ebola virus disease without apparent loss of assay sensitivity.
Protocol > Research Study
Kosack CS, Page AL, Shanks L, Chaillet P, Beelaert G, et al.
2018 July 1
Objectives
3.1 Primary objective
To evaluate the overall and site-specific performance of the diagnostic algorithm performed at 6
MSF African program sites (i.e. using RDT results from the program sites) comparing using the
diagnostic algorithm with ELISA, LIA, EIA-Ag and DNA-PCR as gold standard.
3.2 Secondary objectives
To evaluate the accuracy (sensitivity, specificity and predictive values) of Orgenics
ImmunoComb® II HIV 1&2 Combfirm as an HIV confirmatory test.
To model different HIV RDT testing algorithms in order to define acceptable testing algorithm in
each study setting (i.e. using RDT results from reference laboratory).
To determine the inter-user reliability of RDT testing (i.e. program sites vs. reference laboratory)
To evaluate accuracy of each HIV RDT measured by the sensitivity (SN), specificity (SP) and
predictive values based on the prevalence of each testing centre.
To evaluate the accuracy of HIV testing using DPS samples for quality control purpose in HIV
testing.
To assess whether additional confirmatory testing (i.e. Orgenics ImmunoComb®
II HIV 1&2
Combfirm) improves the accuracy of the diagnostic algorithm used at the different study sites.
To perform a descriptive analysis on the differentiation between HIV 1 and 2 of the
discriminative RDTs.
3.1 Primary objective
To evaluate the overall and site-specific performance of the diagnostic algorithm performed at 6
MSF African program sites (i.e. using RDT results from the program sites) comparing using the
diagnostic algorithm with ELISA, LIA, EIA-Ag and DNA-PCR as gold standard.
3.2 Secondary objectives
To evaluate the accuracy (sensitivity, specificity and predictive values) of Orgenics
ImmunoComb® II HIV 1&2 Combfirm as an HIV confirmatory test.
To model different HIV RDT testing algorithms in order to define acceptable testing algorithm in
each study setting (i.e. using RDT results from reference laboratory).
To determine the inter-user reliability of RDT testing (i.e. program sites vs. reference laboratory)
To evaluate accuracy of each HIV RDT measured by the sensitivity (SN), specificity (SP) and
predictive values based on the prevalence of each testing centre.
To evaluate the accuracy of HIV testing using DPS samples for quality control purpose in HIV
testing.
To assess whether additional confirmatory testing (i.e. Orgenics ImmunoComb®
II HIV 1&2
Combfirm) improves the accuracy of the diagnostic algorithm used at the different study sites.
To perform a descriptive analysis on the differentiation between HIV 1 and 2 of the
discriminative RDTs.
Conference Material > Poster
Gil Cuesta J, Thallinger M, Antierens A, Caluwaerts A, Chaillet P, et al.
MSF Scientific Days UK 2018: Research. 2018 May 14; DOI:10.7490/f1000research.1115454.1