Three year evaluation of Xpert MTB/RIF in a low prevalence tuberculosis setting: A Scottish perspective

Benjamin J. Parcell; Anna Jarchow-MacDonald; Amie-Louise Seagar; Ian Laurenson; Gordon J. Prescott; Michael Lockhart

doi:10.1016/j.jinf.2017.02.005

Three year evaluation of Xpert MTB/RIF in a low prevalence tuberculosis setting: A Scottish perspective

Benjamin J. Parcell (Lead / Corresponding author), Anna Jarchow-MacDonald, Amie-Louise Seagar, Ian Laurenson, Gordon J. Prescott, Michael Lockhart

Research output: Contribution to journal › Article › peer-review

11 Citations (Scopus)

Abstract

OBJECTIVES: Xpert MTB/RIF (Cepheid) is a rapid molecular assay shown to be sensitive and specific for pulmonary tuberculosis (TB) diagnosis in highly endemic countries. We evaluated its diagnostic performance in a low TB prevalence setting, examined rifampicin resistance detection and quantitative capabilities predicting graded auramine microscopy and time to positivity (TTP) of culture.

METHODS: Xpert MTB/RIF was used to test respiratory samples over a 3 year period. Samples underwent graded auramine microscopy, solid/ liquid culture, in-house IS6110 real-time PCR, and GenoType MTBDRplus (HAIN Lifescience) to determine rifampicin and/or isoniazid resistance.

RESULTS: A total of 2103 Xpert MTB/RIF tests were performed. Compared to culture sensitivity was 95.8%, specificity 99.5%, positive predictive value (PPV) 82.1%, and negative predictive value (NPV) 99.9%. A positive correlation was found between auramine microscopy grade and Xpert MTB/RIF assay load. We found a clear reduction in the median TTP as Xpert MTB/RIF assay load increased. Rifampicin resistance was detected.

CONCLUSIONS: Xpert MTB/RIF was rapid and accurate in diagnosing pulmonary TB in a low prevalence area. Rapid results will influence infection prevention and control and treatment measures. The excellent NPV obtained suggests further work should be carried out to assess its role in replacing microscopy.

Original language	English
Pages (from-to)	466-472
Number of pages	7
Journal	Journal of Infection
Volume	74
Issue number	5
Early online date	22 Feb 2017
DOIs	https://doi.org/10.1016/j.jinf.2017.02.005
Publication status	Published - May 2017

Keywords

Journal article
Xpert MTB/RIF
Mycobacterium tuberculosis
Tuberculosis
Molecular testing
Early diagnosis
Nucleic acid amplification

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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title = "Three year evaluation of Xpert MTB/RIF in a low prevalence tuberculosis setting: A Scottish perspective",

abstract = "OBJECTIVES: Xpert MTB/RIF (Cepheid) is a rapid molecular assay shown to be sensitive and specific for pulmonary tuberculosis (TB) diagnosis in highly endemic countries. We evaluated its diagnostic performance in a low TB prevalence setting, examined rifampicin resistance detection and quantitative capabilities predicting graded auramine microscopy and time to positivity (TTP) of culture.METHODS: Xpert MTB/RIF was used to test respiratory samples over a 3 year period. Samples underwent graded auramine microscopy, solid/ liquid culture, in-house IS6110 real-time PCR, and GenoType MTBDRplus (HAIN Lifescience) to determine rifampicin and/or isoniazid resistance.RESULTS: A total of 2103 Xpert MTB/RIF tests were performed. Compared to culture sensitivity was 95.8%, specificity 99.5%, positive predictive value (PPV) 82.1%, and negative predictive value (NPV) 99.9%. A positive correlation was found between auramine microscopy grade and Xpert MTB/RIF assay load. We found a clear reduction in the median TTP as Xpert MTB/RIF assay load increased. Rifampicin resistance was detected.CONCLUSIONS: Xpert MTB/RIF was rapid and accurate in diagnosing pulmonary TB in a low prevalence area. Rapid results will influence infection prevention and control and treatment measures. The excellent NPV obtained suggests further work should be carried out to assess its role in replacing microscopy.",

keywords = "Journal article, Xpert MTB/RIF, Mycobacterium tuberculosis , Tuberculosis, Molecular testing , Early diagnosis, Nucleic acid amplification",

author = "Parcell, {Benjamin J.} and Anna Jarchow-MacDonald and Amie-Louise Seagar and Ian Laurenson and Prescott, {Gordon J.} and Michael Lockhart",

note = "This project has received no funding support.",

year = "2017",

month = may,

doi = "10.1016/j.jinf.2017.02.005",

language = "English",

volume = "74",

pages = "466--472",

journal = "Journal of Infection",

issn = "0163-4453",

publisher = "Elsevier",

number = "5",

}

TY - JOUR

T1 - Three year evaluation of Xpert MTB/RIF in a low prevalence tuberculosis setting

T2 - A Scottish perspective

AU - Parcell, Benjamin J.

AU - Jarchow-MacDonald, Anna

AU - Seagar, Amie-Louise

AU - Laurenson, Ian

AU - Prescott, Gordon J.

AU - Lockhart, Michael

N1 - This project has received no funding support.

PY - 2017/5

Y1 - 2017/5

N2 - OBJECTIVES: Xpert MTB/RIF (Cepheid) is a rapid molecular assay shown to be sensitive and specific for pulmonary tuberculosis (TB) diagnosis in highly endemic countries. We evaluated its diagnostic performance in a low TB prevalence setting, examined rifampicin resistance detection and quantitative capabilities predicting graded auramine microscopy and time to positivity (TTP) of culture.METHODS: Xpert MTB/RIF was used to test respiratory samples over a 3 year period. Samples underwent graded auramine microscopy, solid/ liquid culture, in-house IS6110 real-time PCR, and GenoType MTBDRplus (HAIN Lifescience) to determine rifampicin and/or isoniazid resistance.RESULTS: A total of 2103 Xpert MTB/RIF tests were performed. Compared to culture sensitivity was 95.8%, specificity 99.5%, positive predictive value (PPV) 82.1%, and negative predictive value (NPV) 99.9%. A positive correlation was found between auramine microscopy grade and Xpert MTB/RIF assay load. We found a clear reduction in the median TTP as Xpert MTB/RIF assay load increased. Rifampicin resistance was detected.CONCLUSIONS: Xpert MTB/RIF was rapid and accurate in diagnosing pulmonary TB in a low prevalence area. Rapid results will influence infection prevention and control and treatment measures. The excellent NPV obtained suggests further work should be carried out to assess its role in replacing microscopy.

AB - OBJECTIVES: Xpert MTB/RIF (Cepheid) is a rapid molecular assay shown to be sensitive and specific for pulmonary tuberculosis (TB) diagnosis in highly endemic countries. We evaluated its diagnostic performance in a low TB prevalence setting, examined rifampicin resistance detection and quantitative capabilities predicting graded auramine microscopy and time to positivity (TTP) of culture.METHODS: Xpert MTB/RIF was used to test respiratory samples over a 3 year period. Samples underwent graded auramine microscopy, solid/ liquid culture, in-house IS6110 real-time PCR, and GenoType MTBDRplus (HAIN Lifescience) to determine rifampicin and/or isoniazid resistance.RESULTS: A total of 2103 Xpert MTB/RIF tests were performed. Compared to culture sensitivity was 95.8%, specificity 99.5%, positive predictive value (PPV) 82.1%, and negative predictive value (NPV) 99.9%. A positive correlation was found between auramine microscopy grade and Xpert MTB/RIF assay load. We found a clear reduction in the median TTP as Xpert MTB/RIF assay load increased. Rifampicin resistance was detected.CONCLUSIONS: Xpert MTB/RIF was rapid and accurate in diagnosing pulmonary TB in a low prevalence area. Rapid results will influence infection prevention and control and treatment measures. The excellent NPV obtained suggests further work should be carried out to assess its role in replacing microscopy.

KW - Journal article

KW - Xpert MTB/RIF

KW - Mycobacterium tuberculosis

KW - Tuberculosis

KW - Molecular testing

KW - Early diagnosis

KW - Nucleic acid amplification

U2 - 10.1016/j.jinf.2017.02.005

DO - 10.1016/j.jinf.2017.02.005

M3 - Article

C2 - 28237624

SN - 0163-4453

VL - 74

SP - 466

EP - 472

JO - Journal of Infection

JF - Journal of Infection

IS - 5

ER -

Three year evaluation of Xpert MTB/RIF in a low prevalence tuberculosis setting: A Scottish perspective

Abstract

Keywords

UN SDGs

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