scholarly journals An Early Morning Sputum Sample Is Necessary for the Diagnosis of Pulmonary Tuberculosis, Even with More Sensitive Techniques: A Prospective Cohort Study among Adolescent TB-Suspects in Uganda

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Willy Ssengooba ◽  
David P. Kateete ◽  
Anne Wajja ◽  
Eric Bugumirwa ◽  
Gerald Mboowa ◽  
...  
Keyword(s):  
Diagnostic Yield ◽  
Sputum Sample ◽  
Early Morning ◽  
Sputum Culture ◽  
World Health ◽  
Smear Microscopy ◽  
Indicator Tube ◽  
Lowenstein Jensen ◽  
Health Organization ◽  
Growth Indicator

The World Health Organization (WHO) recommends collection of two sputum samples for tuberculosis (TB) diagnosis, with at least one being an early morning (EM) using smear microscopy. It remains unclear whether this is necessary even when sputum culture is employed. Here, we determined the diagnostic yield from spot and the incremental yield from the EM sputum sample cultures among TB-suspected adolescents from rural Uganda. Sputum samples (both spot and early-morning) from 1862 adolescents were cultured by the Lowenstein-Jensen (LJ) and Mycobacterium Growth Indicator Tube (MGIT) methods. For spot samples, the diagnostic yields for TB were 19.0% and 57.1% with LJ and MGIT, respectively, whereas the incremental yields (not totals) of the early-morning sample were 9.5% and 42.9% (P<0.001) with LJ and MGIT, respectively. Among TB-suspected adolescents in rural Uganda, the EM sputum culture has a high incremental diagnostic yield. Therefore, EM sputum in addition to spot sample culture is necessary for improved TB case detection.

scholarly journals Performance of Xpert® MTB/RIF among tuberculosis outpatients in Lilongwe, Malawi

2017 ◽  
Vol 6 (2) ◽  
Author(s):  
Tarsizio Chikaonda ◽  
Nelson Nguluwe ◽  
Brian Barnett ◽  
Runa H. Gokhale ◽  
Robert Krysiak ◽  
...  
Keyword(s):  
Predictive Value ◽  
Diagnostic Yield ◽  
Fluorescent Microscopy ◽  
Cross Reactivity ◽  
Smear Microscopy ◽  
Indicator Tube ◽  
Or Groups ◽  
Lowenstein Jensen ◽  
Culture Positive ◽  
Growth Indicator

Background: Xpert® MTB/RIF is a molecular test for the detection of Mycobacterium tuberculosis and rifampicin resistance. It is considered to be a great advance over smear microscopy and culture. However, there is very little information regarding the performance characteristics of Xpert MTB/RIF in Malawi.Objective: We aimed to evaluate the performance of Xpert MTB/RIF in a Malawian setting.Methods: Stored sputum pellets were processed on Xpert MTB/RIF between June 2012 andMay 2014. Results were compared to mycobacteria growth indicator tube and Löwenstein-Jensen cultures, LED fluorescent microscopy and GenoType® MTBDRplus assay. Rifampicinresistance was confirmed by DNA sequencing.Results: Of the 348 specimens with valid Xpert MTB/RIF results, 129/348 (37%) were smearpositive and 198/348 (57%) were culture-positive. Xpert MTB/RIF demonstrated a sensitivity of 93.8% (95% CI 89.4% – 96.8%) and specificity of 97.4% (95% CI 93.5% – 99.3%), with a positive predictive value of 97.8% (95% CI 94.6% – 99.4%) and a negative predictive value of 92.6% (95% CI 87.4% – 96.1%). Xpert MTB/RIF correctly identified 185/186 (99.5%) rifampicin sensitive and 2/2 (100%) rifampicin-resistant M. tuberculosis strains. Mutations were notdetected by sequencing in one isolate which was rifampicin resistant on Xpert MTB/RIF butsensitive on MTBDRplus. Four non-tuberculous mycobacteria grew from four smear-negativespecimens, namely, M. avium (n = 1) and M. intracellulare (n = 3). No cross-reactivity wasobserved with any of the non-tuberculous mycobacteria when using Xpert MTB/RIF.Conclusion: When fully implemented, Xpert MTB/RIF may have an impact on patient care inMalawi. The increased diagnostic yield of Xpert MTB/RIF over smear microscopy can increaselaboratory-confirmed tuberculosis detection and ensure that treatment is given to appropriateindividuals or groups.

scholarly journals Spot Specimen Testing With GeneXpert® MTB/RIF Results In More Complete TB Diagnostic Results Than Morning Specimens

2021 ◽  
Author(s):  
Faridath Massou ◽  
Merlin Fandohan ◽  
Ablo Prudence Wachinou ◽  
Schadrac Christin Agbla ◽  
Gildas Agodokpessi ◽  
...  
Keyword(s):  
World Health Organization ◽  
Bacterial Load ◽  
Early Morning ◽  
World Health ◽  
Smear Microscopy ◽  
Lower Sensitivity ◽  
Reference Laboratory ◽  
Single Specimen ◽  
The World ◽  
Health Organization

Abstract Background: The diagnosis of Tuberculosis (TB) using smear microscopy has been based on testing 2 specimens: one spot and one early morning sputum. Recently, the World Health Organization (WHO) recommended to replace, whenever possible, microscopy with GeneXpert® MTB/RIF performed on a single specimen. However, as the bacterial load is higher in early morning specimens than in spot specimens, one could expect lower sensitivity of GeneXpert® MTB/RIF performed only on spot specimens. In this study, we compared results of GeneXpert® MTB/RIF on spot specimens versus early morning specimens, under programmatic conditions in Cotonou, Benin. Methods: From June to September 2018, all sputa received from presumptive TB patients at the Supranational Reference Laboratory for Tuberculosis of Cotonou were included in the study. From each patient, two specimens were collected (one spot and one early morning) and GeneXpert® MTB/RIF was performed on both specimens. Results: In total, 886 participants were included in the study, of whom 737 provided both sputa and 149 (16.8%) gave only the spot specimen. For the 737 participants who provided both sputa, GeneXpert® MTB/RIF was positive for both specimens in 152 participants; for three participants GeneXpert® MTB/RIF was positive on spot specimen but negative on morning specimen while for another three, the test was positive on morning specimen but negative on spot specimen. The overall percentage of agreement was excellent (99.2%) with a very positive and negative percent agreement greater than 98%.Conclusions: For TB diagnosis under programmatic conditions in Cotonou, GeneXpert® MTB/RIF in spot specimens gave similar results with the test in morning specimens. Performing GeneXpert® MTB/RIF in both specimens did not significantly increase the number of cases detected. To avoid losing patients from the diagnostic cascade, it is preferable to test sputa produced at the time of visit.

scholarly journals Spot specimen testing with GeneXpert MTB/RIF results compared to morning specimen in a programmatic setting in Cotonou, Benin

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Faridath Massou ◽  
Merlin Fandohan ◽  
Ablo Prudence Wachinou ◽  
Schadrac Christin Agbla ◽  
Gildas Agodokpessi ◽  
...  
Keyword(s):  
World Health Organization ◽  
Bacterial Load ◽  
Early Morning ◽  
World Health ◽  
Smear Microscopy ◽  
Lower Sensitivity ◽  
Reference Laboratory ◽  
Single Specimen ◽  
The World ◽  
Health Organization

Abstract Background The diagnosis of tuberculosis (TB) using smear microscopy has been based on testing two specimens: one spot and one early morning sputa. Recently, the World Health Organization (WHO) has recommended to replace, whenever possible, microscopy with GeneXpert® MTB/RIF performed on a single specimen. However, as the bacterial load is higher in early morning specimens than in spot specimens, one could expect lower sensitivity of GeneXpert® MTB/RIF performed only on spot specimens. In this study, we compared results of GeneXpert® MTB/RIF on spot specimens versus early morning specimens, under programmatic conditions in Cotonou, Benin. Methods From June to September 2018, all sputa received from presumptive TB patients at the Supranational Reference Laboratory for Tuberculosis of Cotonou were included in the study. From each patient, two specimens were collected (one spot and one early morning) and GeneXpert® MTB/RIF was performed on both specimens. Results In total, 886 participants were included in the study, of whom 737 provided both sputa and 149 (16.8%) gave only the spot specimen. For the 737 participants who provided both sputa, GeneXpert® MTB/RIF was positive for both specimens in 152 participants; for three participants GeneXpert® MTB/RIF was positive on spot specimen but negative on morning specimen while for another three, the test was positive on morning specimen but negative on spot specimen. The overall percentage of agreement was excellent (99.2%) with a positive and negative percent agreement greater than 98%. Conclusion For TB diagnosis under programmatic conditions in Cotonou, GeneXpert® MTB/RIF in spot specimens gave similar results with the test in morning specimens. Performing GeneXpert® MTB/RIF in both specimens did not significantly increase the number of cases detected. To avoid losing patients from the diagnostic cascade, it is preferable to test sputa produced at the time of the first visit at the health center.

The MPB64 immunochromatography assay: an analysis of doubtful results

2020 ◽  
Vol 50 (4) ◽  
pp. 340-343
Author(s):  
Chanchal Kumar ◽  
Kamal Shrivastava ◽  
Anupriya Singh ◽  
Naresh Kumar Sharma ◽  
Jitender Yadav ◽  
...  
Keyword(s):  
Positive Culture ◽  
World Health ◽  
Indicator Tube ◽  
Polymerase Chain ◽  
Probe Assay ◽  
Mgit Culture ◽  
Health Organization ◽  
Culture Positive ◽  
Positive Results ◽  
Growth Indicator

Culture remains the gold standard for tuberculosis (TB) diagnosis, and the mycobacteria growth indicator tube (MGIT), endorsed by the World Health Organization (WHO), is widely used. Further identification of a positive culture is done with the help of an immunochromatography assay, which often shows faint bands that are difficult to interpret. We analysed 125 BACTEC MGIT culture positive results, of which 11/16 (68.7%) of the doubtful assays, analysed by MGIT™ TBc Identification test (TBcId), were positive for Mycobacterium tuberculosis complex (MTBC), the remaining being non-tuberculous mycobacteria as determined by an in-house duplex polymerase chain reaction and line probe assay. Guidelines on faint or doubtful bands in immunochromatography assays are important so as not to overlook true-positive cases of TB.

scholarly journals Promising Novel Biomarkers in Cardiovascular Diseases

2021 ◽  
Vol 11 (8) ◽  
pp. 3654
Author(s):  
Brigitte Sipos ◽  
Peter Jirak ◽  
Vera Paar ◽  
Richard Rezar ◽  
Moritz Mirna ◽  
...  
Keyword(s):  
Cardiovascular Diseases ◽  
Diagnostic Yield ◽  
Accurate Estimate ◽  
World Health ◽  
Current Status ◽  
Fatty Acid Binding ◽  
Type Plasminogen Activator ◽  
Common Causes ◽  
Novel Biomarkers ◽  
Health Organization

Cardiovascular diseases remain the most common causes of death globally, according to the World Health Organization. In recent years, a great number of biomarkers have been investigated, whereas only some have gained value in the diagnosis, prognosis, and risk stratification of different cardiovascular illnesses. As numerous studies have investigated the diagnostic yield of novel biomarkers in various disease entities every year, this review aims to provide an overview of the current status of four promising representatives. In particular, this manuscript refers to soluble suppression of tumorigenicity 2 (sST2), heart-type fatty acid binding protein (H-FABP), growth differentiation factor (GDF-15) and soluble urokinase-type plasminogen activator receptor (suPAR). These markers are of special interest as they are thought to provide an accurate estimate of cardiovascular risk in certain patient populations, especially those with pre-existing diseases, such as obesity or diabetes mellitus. We sought to give an overview of their function, individual diagnostic and predictive value and determination in the laboratory. A review of the literature regarding the aforementioned cardiovascular biomarkers yielded manifold results with respect to their individual diagnostic and prognostic value. Yet, the clinical relevance of these findings remains unclear, warranting further studies to identify their optimal use in clinical routine.

scholarly journals Accuracy of Xpert Ultra in Diagnosis of Pulmonary Tuberculosis among Children in Uganda: a Substudy from the SHINE Trial

2020 ◽  
Vol 58 (9) ◽  
Author(s):  
Willy Ssengooba ◽  
Jean de Dieu Iragena ◽  
Lydia Nakiyingi ◽  
Serestine Mujumbi ◽  
Eric Wobudeya ◽  
...  
Keyword(s):  
Positive Result ◽  
Diagnostic Challenge ◽  
Indicator Tube ◽  
Lowenstein Jensen ◽  
Mgit Culture ◽  
Mycobacterial Growth ◽  
Culture Positive ◽  
Mycobacterial Growth Indicator Tube ◽  
Higher Sensitivity ◽  
Growth Indicator

ABSTRACT Childhood tuberculosis (TB) presents significant diagnostic challenges associated with paucibacillary disease and requires a more sensitive test. We evaluated the diagnostic accuracy of Xpert MTB/RIF Ultra (Ultra) compared to other microbiological tests using respiratory samples from Ugandan children in the SHINE trial. SHINE is a randomized trial evaluating shorter treatment in 1,204 children with minimal TB disease in Africa and India. Among 352 samples and one cervical lymph node fine needle aspirate, one sample was randomly selected per patient and tested with the Xpert MTB/RIF assay (Xpert) and with Lowenstein-Jensen medium (LJ) and liquid mycobacterial growth indicator tube (MGIT) cultures. We selected only uncontaminated stored sample pellets for Ultra testing. We estimated the sensitivity of Xpert and Ultra against culture and a composite microbiological reference standard (any positive result). Of 398 children, 353 (89%) had culture, Xpert, and Ultra results. The median age was 2.8 years (interquartile range [IQR], 1.3 to 5.3); 8.5% (30/353) were HIV infected, and 54.4% (192/353) were male. Of the 353, 31 (9%) were positive by LJ and/or MGIT culture, 36 (10%) by Ultra, and 16 (5%) by Xpert. Sensitivities (95% confidence intervals [CI]) were 58% (39 to 65% [18/31]) for Ultra and 45% (27 to 64% [14/31]) for Xpert against any culture-positive result, with false positives of <1% and 5.5% for Xpert and Ultra. Against a composite microbiological reference, sensitivities were 72% (58 to 84% [36/50]) for Ultra and 32% (20 to 47% [16/50]) for Xpert. However, there were 17 samples that were positive only with Ultra (majority trace). Among children screened for minimal TB in Uganda, Ultra has higher sensitivity than Xpert. This represents an important advance for a condition which has posed a diagnostic challenge for decades.

scholarly journals Tuberculosis diagnosis and treatment under uncertainty

2019 ◽  
Vol 116 (46) ◽  
pp. 22990-22997
Author(s):  
Rachel Cassidy ◽  
Charles F. Manski
Keyword(s):  
Diagnostic Test ◽  
Diagnostic Testing ◽  
World Health ◽  
Smear Microscopy ◽  
Theoretic Model ◽  
Test Accuracy ◽  
Partial Knowledge ◽  
Deep Uncertainty ◽  
Tuberculosis Diagnosis ◽  
Health Organization

In 2017, 1.6 million people worldwide died from tuberculosis (TB). A new TB diagnostic test—Xpert MTB/RIF from Cepheid—was endorsed by the World Health Organization in 2010. Trials demonstrated that Xpert is faster and has greater sensitivity and specificity than smear microscopy—the most common sputum-based diagnostic test. However, subsequent trials found no impact of introducing Xpert on morbidity and mortality. We present a decision-theoretic model of how a clinician might decide whether to order Xpert or other tests for TB, and whether to treat a patient, with or without test results. Our first result characterizes the conditions under which it is optimal to perform empirical treatment; that is, treatment without diagnostic testing. We then examine the implications for decision making of partial knowledge of TB prevalence or test accuracy. This partial knowledge generates ambiguity, also known as deep uncertainty, about the best testing and treatment policy. In the presence of such ambiguity, we show the usefulness of diversification of testing and treatment.

scholarly journals GeneXpert MTB/RIF Assay for Rapid Identification of Mycobacterium Tuberculosis and Rifampicin Resistance Directly from Sputum Sample

2017 ◽  
Vol 7 (2) ◽  
pp. 86-89 ◽  
Author(s):  
Nourjahan Laskar ◽  
Md Akram Hossain ◽  
Jannatul Fardows ◽  
Mominur Rahman
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Sputum Sample ◽  
Rapid Identification ◽  
Rapid Diagnosis ◽  
World Health ◽  
Multi Drug Resistance ◽  
Drug Resistant ◽  
Resistant Tuberculosis ◽  
The World ◽  
Health Organization

Background: The World Health Organization has endorsed the use of molecular methods for the detection of tuberculosis (TB) and drug resistant TB as a rapid method. In Bangladesh, the Xpert MTB/RIF assay has been implemented into reference laboratories for diagnosis of TB and also MDR TB.Objective: Drug resistant tuberculosis has long been a common problem prevailing in our country. The present study focused on the rapid identification of Mycobacterium tuberculosis as well as drug resistance.Materials and Methods: Sputum samples from a total of 107 cases, assumed as multi-drug resistance tuberculosis, were studied through GeneXpert assay.Results: Out of 107 cases, 91 (85.05%) were detected having M. tuberculosis ? 64 (59.81%) were rifampicin sensitive and 27 (25.23%) were rifampicin resistant. The sensitivity and specificity of the GeneXpert are 87.64% and 75% respectively.Conclusion: GeneXpert assay can be considered for the rapid diagnosis of drug resistant tuberculosis.J Enam Med Col 2017; 7(2): 86-89

Detection of mycobacteria in clinical specimen using the mycobacteria growth indicator tube (MGIT) and the Lowenstein Jensen medium

1999 ◽  
Vol 154 (2) ◽  
pp. 151-155 ◽  
Author(s):  
S. Levidiotou ◽  
D. Papamichael ◽  
E. Gessouli ◽  
S. Golegou ◽  
S. Anagnostou ◽  
...  
Keyword(s):  
Clinical Specimen ◽  
Indicator Tube ◽  
Lowenstein Jensen ◽  
Growth Indicator
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