Journal Article > ResearchFull Text
PLOS One. 2010 June 11; Volume 5 (Issue 6); DOI:10.1371/journal.pone.0011086
Rose AMC, Mueller JE, Gerstl S, Njanpop-Lafourcade BM, Page AL, et al.
PLOS One. 2010 June 11; Volume 5 (Issue 6); DOI:10.1371/journal.pone.0011086
Meningococcal meningitis outbreaks occur every year during the dry season in the "meningitis belt" of sub-Saharan Africa. Identification of the causative strain is crucial before launching mass vaccination campaigns, to assure use of the correct vaccine. Rapid agglutination (latex) tests are most commonly available in district-level laboratories at the beginning of the epidemic season; limitations include a short shelf-life and the need for refrigeration and good technical skills. Recently, a new dipstick rapid diagnostic test (RDT) was developed to identify and differentiate disease caused by meningococcal serogroups A, W135, C and Y. We evaluated the diagnostic performance of this dipstick RDT during an urban outbreak of meningitis caused by N. meningitidis serogroup A in Ouagadougou, Burkina Faso; first against an in-country reference standard of culture and/or multiplex PCR; and second against culture and/or a highly sensitive nested PCR technique performed in Oslo, Norway. We included 267 patients with suspected acute bacterial meningitis. Using the in-country reference standard, 50 samples (19%) were positive. Dipstick RDT sensitivity (N = 265) was 70% (95%CI 55-82) and specificity 97% (95%CI 93-99). Using culture and/or nested PCR, 126/259 (49%) samples were positive; dipstick RDT sensitivity (N = 257) was 32% (95%CI 24-41), and specificity was 99% (95%CI 95-100). We found dipstick RDT sensitivity lower than values reported from (i) assessments under ideal laboratory conditions (>90%), and (ii) a prior field evaluation in Niger [89% (95%CI 80-95)]. Specificity, however, was similar to (i), and higher than (ii) [62% (95%CI 48-75)]. At this stage in development, therefore, other tests (e.g., latex) might be preferred for use in peripheral health centres. We highlight the value of field evaluations for new diagnostic tests, and note relatively low sensitivity of a reference standard using multiplex vs. nested PCR. Although the former is the current standard for bacterial meningitis surveillance in the meningitis belt, nested PCR performed in a certified laboratory should be used as an absolute reference when evaluating new diagnostic tests.
Journal Article > Short ReportFull Text
Pan Afr Med J. 2017 January 18; Volume 26; DOI:10.11604/pamj.2017.26.27.11111
Asfaw Y, Boateng I, Calderon M, Caleo GNC, Conteh LA, et al.
Pan Afr Med J. 2017 January 18; Volume 26; DOI:10.11604/pamj.2017.26.27.11111
Journal Article > ResearchFull Text
PLoS Negl Trop Dis. 2013 August 15; Volume 7 (Issue 8); DOI:10.1371/journal.pntd.0002366
Martinez-Pino I, Luquero FJ, Sakoba K, Sylla S, Haile M, et al.
PLoS Negl Trop Dis. 2013 August 15; Volume 7 (Issue 8); DOI:10.1371/journal.pntd.0002366
During the 2012 cholera outbreak in the Republic of Guinea, the Ministry of Health, supported by Médecins Sans Frontières - Operational Center Geneva, used the oral cholera vaccine Shanchol as a part of the emergency response. The rapid diagnostic test (RDT) Crystal VC, widely used during outbreaks, detects lipopolysaccharide antigens of Vibrio cholerae O1 and O139, both included in Shanchol. In the context of reactive use of a whole-cell cholera vaccine in a region where cholera cases have been reported, it is essential to know what proportion of vaccinated individuals would be reactive to the RDT and for how long after vaccination.
Journal Article > ReviewFull Text
Curr Opin HIV AIDS. 2017 May 1; Volume 12 (Issue 3); DOI:10.1097/COH.0000000000000370
Easterbrook PJ, Roberts TR, Sands A, Peeling RW
Curr Opin HIV AIDS. 2017 May 1; Volume 12 (Issue 3); DOI:10.1097/COH.0000000000000370
Journal Article > ResearchFull Text
PLOS One. 2015 April 17; Volume 10 (Issue 4); DOI:10.1371/journal.pone.0122433
Kosack CS, de Kieviet W, Bayrak K, Milovic A, Page AL
PLOS One. 2015 April 17; Volume 10 (Issue 4); DOI:10.1371/journal.pone.0122433
Creatinine is a parameter that is required to monitor renal function and is important to follow in patients under treatment with potentially toxic renal drugs, such as the anti-HIV drug Tenofovir. A point of care instrument to measure creatinine would be useful for patients monitoring in resource-limited settings, where more instruments that are sophisticated are not available. The StatSensor Xpress Creatinine (Nova Biomedical Cooperation, Waltham, MA, USA) point of care analyzer was evaluated for its diagnostic performance in indicating drug therapy change. Creatinine was measured in parallel using the Nova StatSensor Xpress Creatinine analyzer and the Vitros 5,1FS (Ortho Clinical Diagnostics, Inc, Rochester, USA), which served as reference standard. The precision (i.e., repeatability and reproducibility) and accuracy of the StatSensor Xpress Creatinine analyzer were calculated using a panel of specimens with normal, low pathological and high pathological values. Two different Nova StatSensor Xpress Creatinine analyzers were used for the assessment of accuracy using repeated measurements. The coefficient of variation of the StatSensor Xpress Creatinine analyzers ranged from 2.3 to 5.9% for repeatability and from 4.2 to 9.0% for between-run reproducibility. The concordance correlation agreement was good except for high values (>600 µmol/L). The Bland-Altman analysis in high pathological specimens suggests that the Nova StatSensor Xpress Creatinine test tends to underestimate high creatinine values (i.e., >600 µmol/L). The Nova StatSensor Xpress Creatinine analyzers showed acceptable to good results in terms of repeatability, inter-device reproducibility and between-run reproducibility over time using quality control reagents. The analyzer was found sufficiently accurate for detecting pathological values in patients (age >10 year) and can be used with a moderate risk of misclassification.
Journal Article > ResearchFull Text
PLOS One. 2011 May 31; Volume 6 (Issue 5); DOI:10.1371/journal.pone.0020175
Bonnet MMB, Gagnidze L, Guerin PJ, Bonte L, Ramsay AR, et al.
PLOS One. 2011 May 31; Volume 6 (Issue 5); DOI:10.1371/journal.pone.0020175
Sputum microscopy is the only diagnostic for tuberculosis (TB) available at peripheral levels of health service in resource-poor countries. Its sensitivity is reduced in high HIV-prevalence settings. Sodium hypochlorite (NaOCl) specimen sedimentation prior microscopy and light-emitting diode (LED)-fluorescence microscopy (FM) can individually improve performance of microscopy. This study aimed to evaluate the performance of combined LED-FM and NaOCl sputum sedimentation for TB detection at peripheral level of health services.
Protocol > Research Study
Kosack CS, Halton J, Greig J, Shanks L, Spijker S
2018 July 1
PRIMARY OBJECTIVE OF STUDY
• To demonstrate the extent of change in patient management through the availability of digital X-ray with teleradiology consultation.
SECONDARY OBJECTIVES OF STUDY
• To demonstrate the extent of change in patient diagnosis through the availability of digital X-ray with teleradiology consultation.
• To demonstrate the extent of change in patient diagnosis and management in the subgroup of patients with chest pathologies through the availability of digital X-ray with teleradiology consultation.
• To estimate if the extent of change in diagnosis and management is different in patients < 5 years of age versus ≥5 years of age.
• To demonstrate the extent of change in patient management through the availability of digital X-ray with teleradiology consultation.
SECONDARY OBJECTIVES OF STUDY
• To demonstrate the extent of change in patient diagnosis through the availability of digital X-ray with teleradiology consultation.
• To demonstrate the extent of change in patient diagnosis and management in the subgroup of patients with chest pathologies through the availability of digital X-ray with teleradiology consultation.
• To estimate if the extent of change in diagnosis and management is different in patients < 5 years of age versus ≥5 years of age.
Journal Article > ResearchFull Text
East Afr Med J. 2017 March 31; Volume 6 (Issue 2); 383.; DOI:10.4102/ajlm.v6i2.383
Orikiriza P, Nyehangane D, Atwine D, Kisakye JJ, Kassaza K, et al.
East Afr Med J. 2017 March 31; Volume 6 (Issue 2); 383.; DOI:10.4102/ajlm.v6i2.383
BACKGROUND
To confirm presence of Mycobacterium tuberculosis complex, some tuberculosis culture laboratories still rely on para-nitrobenzoic acid (PNB), a traditional technique that requires sub-culturing of clinical isolates and two to three weeks to give results. Rapid identification tests have improved turnaround times for mycobacterial culture results. Considering the challenges of the PNB method, we assessed the performance of the SD Bioline TB Ag MPT64 assay by using PNB as gold standard to detect M. tuberculosis complex from acid-fast bacilli (AFB) positive cultures.
OBJECTIVES
The aim of this study was to determine the sensitivity, specificity and turnaround time of the SD MPT64 assay for identification of M. tuberculosis complex, in a setting with high prevalence of tuberculosis and HIV.
METHODS
A convenience sample of 690 patients, with tuberculosis symptoms, was enrolled at Epicentre Mbarara Research Centre between April 2010 and June 2011. The samples were decontaminated using NALC-NaOH and re-suspended sediments inoculated in Mycobacterium Growth Indicator Tubes (MGIT) media, then incubated at 37 °C for a maximum of eight weeks. A random sample of 50 known negative cultures and 50 non-tuberculous mycobacteria isolates were tested for specificity, while sensitivity was based on AFB positivity. The time required from positive culture to reporting of results was also assessed with PNB used as the gold standard.
RESULTS
Of the 138 cultures that were AFB-positive, the sensitivity of the SD MPT64 assay was 100.0% [95% CI: 97.3 - 100] and specificity was 100.0% (95% CI, 96.4 - 100). The median time from a specimen receipt to confirmation of strain was 10 days [IQR: 8-12] with SD MPT64 and 24 days [IQR: 22-26] with PNB.
CONCLUSION
The SD MPT64 assay is comparable to PNB for identification of M. tuberculosis complex and reduces the time to detection.
To confirm presence of Mycobacterium tuberculosis complex, some tuberculosis culture laboratories still rely on para-nitrobenzoic acid (PNB), a traditional technique that requires sub-culturing of clinical isolates and two to three weeks to give results. Rapid identification tests have improved turnaround times for mycobacterial culture results. Considering the challenges of the PNB method, we assessed the performance of the SD Bioline TB Ag MPT64 assay by using PNB as gold standard to detect M. tuberculosis complex from acid-fast bacilli (AFB) positive cultures.
OBJECTIVES
The aim of this study was to determine the sensitivity, specificity and turnaround time of the SD MPT64 assay for identification of M. tuberculosis complex, in a setting with high prevalence of tuberculosis and HIV.
METHODS
A convenience sample of 690 patients, with tuberculosis symptoms, was enrolled at Epicentre Mbarara Research Centre between April 2010 and June 2011. The samples were decontaminated using NALC-NaOH and re-suspended sediments inoculated in Mycobacterium Growth Indicator Tubes (MGIT) media, then incubated at 37 °C for a maximum of eight weeks. A random sample of 50 known negative cultures and 50 non-tuberculous mycobacteria isolates were tested for specificity, while sensitivity was based on AFB positivity. The time required from positive culture to reporting of results was also assessed with PNB used as the gold standard.
RESULTS
Of the 138 cultures that were AFB-positive, the sensitivity of the SD MPT64 assay was 100.0% [95% CI: 97.3 - 100] and specificity was 100.0% (95% CI, 96.4 - 100). The median time from a specimen receipt to confirmation of strain was 10 days [IQR: 8-12] with SD MPT64 and 24 days [IQR: 22-26] with PNB.
CONCLUSION
The SD MPT64 assay is comparable to PNB for identification of M. tuberculosis complex and reduces the time to detection.
Journal Article > ResearchFull Text
PLOS One. 2012 March 19; Volume 7 (Issue 3); DOI:10.1371/journal.pone.0033704
Kosack CS, Page AL, Van Hulsteijn LT, Lentjes EG
PLOS One. 2012 March 19; Volume 7 (Issue 3); DOI:10.1371/journal.pone.0033704
Thyroid-stimulating hormone (TSH) promotes expression of thyroid hormones which are essential for metabolism, growth, and development. Second-line drugs to treat tuberculosis (TB) can cause hypothyroidism by suppressing thyroid hormone synthesis. Therefore, TSH levels are routinely measured in TB patients receiving second-line drugs, and thyroxin treatment is initiated where indicated. However, standard TSH tests are technically demanding for many low-resource settings where TB is prevalent; a simple and inexpensive test is urgently needed.
Journal Article > ResearchAbstract
J Clin Microbiol. 2019 October 16
Ardizzoni E, Orikiriza P, Ssuuna C, Nyehangane D, Gumsboga M, et al.
J Clin Microbiol. 2019 October 16
Background: Xpert MTB/RIF (Xpert) and culture are the most reliable methods for tuberculosis diagnosis but are still poorly accessible in many low resource countries. We aimed to assess the effect of OMNIgene® SPUTUM (OM-S) and ethanol in preserving sputum for Xpert and OM-S for mycobacteria growth indicator tube (MGIT) testing over a period of 15 and 8 days respectively.
Methods: Sputum were collected from newly diagnosed smear-positive patients. For Xpert, pooled samples were split into 5 aliquots: 3 for Xpert on day 0, 7 and 15 days without additive and 2 with either OM-S or ethanol at day 15. For MGIT, 2 aliquots were tested without preservative and 2 with OM-S at 0 and 8 days.
Results: A total of 48 and 47 samples were included in the analysis for Xpert and culture. With Xpert, using Day 0 as reference, untreated samples stored for 7 and 15 days showed concordance of 45/46 (97.8%) and 46/48 (95.8%). For samples preserved with OM-S or ethanol for 15 days compared with untreated samples processed at day 0 or after 15 days, OM-S concordance was 46/48(95.8%) and 47/48(97.9%), while ethanol was 44/48 (91.7%) and 45/48 (93.8%). With MGIT, concordance between untreated and OM-S treated samples was 21/41(51.2%) at Day 0 and 21/44(47.7%) at day8.
Conclusions: Xpert equally detected TB in OM-S treated and untreated samples up to 15 days but showed slightly lower detection in ethanol treated samples. Among OM-S treated samples, MGIT positivity was significantly lower compared to untreated samples at both time-points.
Methods: Sputum were collected from newly diagnosed smear-positive patients. For Xpert, pooled samples were split into 5 aliquots: 3 for Xpert on day 0, 7 and 15 days without additive and 2 with either OM-S or ethanol at day 15. For MGIT, 2 aliquots were tested without preservative and 2 with OM-S at 0 and 8 days.
Results: A total of 48 and 47 samples were included in the analysis for Xpert and culture. With Xpert, using Day 0 as reference, untreated samples stored for 7 and 15 days showed concordance of 45/46 (97.8%) and 46/48 (95.8%). For samples preserved with OM-S or ethanol for 15 days compared with untreated samples processed at day 0 or after 15 days, OM-S concordance was 46/48(95.8%) and 47/48(97.9%), while ethanol was 44/48 (91.7%) and 45/48 (93.8%). With MGIT, concordance between untreated and OM-S treated samples was 21/41(51.2%) at Day 0 and 21/44(47.7%) at day8.
Conclusions: Xpert equally detected TB in OM-S treated and untreated samples up to 15 days but showed slightly lower detection in ethanol treated samples. Among OM-S treated samples, MGIT positivity was significantly lower compared to untreated samples at both time-points.