scholarly journals Field Evaluation of the Performance of Two Rapid Diagnostic Tests for Meningitis in Niger and Burkina Faso

2021 ◽  
Vol 9 (4) ◽  
pp. 832 ◽  
Author(s):  
Marc Rondy ◽  
Mamadou Tamboura ◽  
Fati Sidikou ◽  
Issaka Yameogo ◽  
Kambire Dinanibe ◽  
...  
Keyword(s):  
Burkina Faso ◽  
Field Evaluation ◽  
Health Centers ◽  
Outbreak Detection ◽  
Health Staff ◽  
Chain Reaction ◽  
Predictive Values ◽  
Independent Evaluation ◽  
Polymerase Chain ◽  
Lateral Flow Tests

New lateral flow tests for the diagnosis of Neisseria meningitidis (Nm) (serogroups A, C, W, X, and Y), MeningoSpeed, and Streptococcus pneumoniae (Sp), PneumoSpeed, developed to support rapid outbreak detection in Africa, have shown good performance under laboratory conditions. We conducted an independent evaluation of both tests under field conditions in Burkina Faso and Niger, in 2018–2019. The tests were performed in the cerebrospinal fluid of suspected meningitis cases from health centers in alert districts and compared to reverse transcription polymerase chain reaction tests performed at national reference laboratories (NRLs). Health staff were interviewed about feasibility. A total of 327 cases were tested at the NRLs, with 26% confirmed Nm (NmC 63% and NmX 37%) and 8% Sp. Sensitivity and specificity were, respectively, 95% (95% CI: 89–99) and 90% (95% CI: 86–94) for Nm and 92% (95% CI: 75–99) and 99% (95% CI: 97–100) for Sp. Positive and negative predictive values were, respectively, 77% (95% CI: 68–85) and 98% (95% CI: 95–100) for Nm and 86% (95% CI: 67–96) and 99% (95% CI: 98–100) for Sp. Concordance showed 82% agreement for Nm and 97% for Sp. Interviewed staff evaluated the tests as easy to use and to interpret and were confident in their readings. Results suggest overall good performance of both tests and potential usefulness in meningitis outbreak detection.

scholarly journals Development of a Bio-PCR Protocol for the Detection of Xanthomonas arboricola pv. pruni

Plant Disease ◽  
2011 ◽  
Vol 95 (9) ◽  
pp. 1109-1115 ◽  
Author(s):  
E. L. Ballard ◽  
R. G. Dietzgen ◽  
L. I. Sly ◽  
C. Gouk ◽  
C. Horlock ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
Field Evaluation ◽  
Subtractive Hybridization ◽  
Epiphytic Bacteria ◽  
Supportive Evidence ◽  
Chain Reaction ◽  
Dna Library ◽  
Xanthomonas Arboricola ◽  
Polymerase Chain

A real-time SYBR Green I assay was developed and evaluated as a biological and enzymatic polymerase chain reaction (Bio-PCR) protocol for the detection of Xanthomonas arboricola pv. pruni. Suppression subtractive hybridization was used to generate a X. arboricola pv. pruni-specific subtracted DNA library, using X. arboricola pv. corylina as the driver strain. Primer pair 29F/R, designed from cloned sequence, showed no homology to GenBank sequences and amplified a 344-bp product in all X. arboricola pv. pruni isolates. Compared with other published X. arboricola pv. pruni primers, this primer pair was shown to be the only one capable of differentiating X. arboricola pv. pruni from all other X. arboricola pathovars. A real-time assay was developed and shown to be capable of detecting less than 10 CFU and 0.1 pg of DNA. Epiphytic bacteria isolated from plum tissue was used to further evaluate the specificity of the assay. A Bio-PCR protocol, developed for field evaluation, confirmed X. arboricola pv. pruni isolation from asymptomatic and symptomatic plum tissue over a 9-week period between host flowering and the first appearance of leaf and fruit symptoms in an orchard. Dilution plating enabled X. arboricola pv. pruni numbers to be quantified, providing supportive evidence for the usefulness of the Bio-PCR protocol in plant pathology and quarantine surveillance.

scholarly journals Performance of a Commercial Polymerase Chain Reaction Test for EndocervicalChlamydia trachomatisInfection in a University Hospital Population

1998 ◽  
Vol 6 (5) ◽  
pp. 224-229
Author(s):  
C. H. Livengood III ◽  
K. A. Boggess ◽  
J. W. Wrenn ◽  
A. P. Murtha
Keyword(s):  
Polymerase Chain Reaction ◽  
Polymerase Chain Reaction Test ◽  
Laboratory Evaluation ◽  
Clinical Samples ◽  
Chain Reaction ◽  
Predictive Values ◽  
Target Dna ◽  
Wide Range ◽  
Polymerase Chain ◽  
Pcr Test

Objectives:To examine the accuracy of a commercial polymerase chain reaction (PCR) test (Amplicor CTR, Roche Diagnostic Systems, Branchburg NJ) for identification of endocervical chlamydial infections through both laboratory evaluation and among a diverse teaching hospital patient population.Methods:Testing of reliable threshold inocula and reproducibility were carried out using laboratory stock organisms. Paired endocervical samples from patients with a wide range of indications were tested by PCR and an established culture procedure, and discrepant pairs were further analyzed to determine true results.Results:Laboratory evaluation suggested that one copy of target DNA from a viable organism consistently yielded a positive result, and test reproducibility was very good, with an overall coefficient of variation of 15%. Compared to true results in 1,588 paired clinical samples from 1,489 women with a 10% prevalence of infection, the PCR test and culture yielded respective sensitivities of 87.4% and 78.0%, and negative predictive values of 98.6% and 97.6%. Specificity and positive predictive value for both tests were 100%. Cost per specimen was nearly identical at $18.84 and $18.88 respectively. Polymerase inhibitors and organisms lacking target DNA were not found in false-negative PCR samples.Conclusion:This commercial PCR test is accurate, cost-competitive, and much faster than culture for diagnosis of endocervical chlamydia infections in our population of intermediate prevalence of chlamydial infection.

scholarly journals Field Evaluation of a Polymerase Chain Reaction-Based Nonisotopic Liquid Hybridization Assay for Malaria Diagnosis

1996 ◽  
Vol 173 (5) ◽  
pp. 1284-1287 ◽  
Author(s):  
D. A. Oliveira ◽  
Y. P. Shi ◽  
A. J. Oloo ◽  
D. A. Boriga ◽  
B. L. Nahlen ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Malaria Diagnosis ◽  
Field Evaluation ◽  
Hybridization Assay ◽  
Chain Reaction ◽  
Polymerase Chain

Polymerase Chain Reaction Assay Coupled with Fluorescence Detection on Microwell Plates for Listeria monocytogenes in Foods

1995 ◽  
Vol 58 (6) ◽  
pp. 614-620 ◽  
Author(s):  
RAÚL J. CANO ◽  
DAWN M. NORTON ◽  
ALMA E. INZUNZA ◽  
JOSÉ GIL SÁNCHEZ ◽  
CHRISTIAN OSTE
Keyword(s):  
Polymerase Chain Reaction ◽  
Listeria Monocytogenes ◽  
Fluorescence Detection ◽  
Polymerase Chain Reaction Assay ◽  
Food Samples ◽  
Fluorescence Measurement ◽  
Chain Reaction ◽  
Predictive Values ◽  
Dairy Food ◽  
Polymerase Chain

This study evaluates a polymerase chain-reaction assay coupled with fluorescence detection (PCR-FD) in microwell plates for Listeria monocytogenes in dairy and food samples. Guanidinium thiocyanate/silica–extracted cultures and milk and dairy-food samples were used as templates for a PCR assay in microwell plates, with a primer pair that amplifies a 221 bp segment of the internal transcribed spacer (ITS), in the presence of 0.5 μg/ml of ethidium bromide. Fluorescence of the PCR products was measured with a CytoFluor 2300 fluorescence measurement system (Millipore Corporation, Bedford, MA). The lowest level of detection of the assay was 10 to 100 CFU. A total of 326 food samples were tested, both by culture and by PCR-FD. The overall sensitivity of the PCR-FD assay was 95.2% and the specificity was 89.9%. Positive and negative predictive values were 74.8% and 99.4%, respectively. Based on the results obtained in this study it appears that the PCR-FD assay described here can be useful for screening a large number of milk and dairy-food samples for contamination by Listeria monocytogenes.

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