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Thorax. Single-step QuantiFERON screening of adult contacts: a prospective cohort study of tuberculosis risk
[Source: Thorax, full text: (LINK). Abstract, edited.]
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<CITE><ABBR>Thorax</ABBR>2013;68:240-246 doi:10.1136/thoraxjnl-2011-200956 </CITE>
<CITE></CITE>
<CITE></CITE>Tuberculosis - Original article
Single-step QuantiFERON screening of adult contacts: a prospective cohort study of tuberculosis risk
Pranabashis Haldar 1,2, Helen Thuraisingam 1, Hemu Patel 3, Nelun Pereira 3, Robert C Free 2, James Entwisle 1, Martin Wiselka 4, Edwyn Wren Hoskyns 5, Philip Monk 6, Michael R Barer 2,3,*, Gerrit Woltmann 1,*
Author Affiliations: <SUP>1</SUP>Department of Respiratory Medicine, Institute for Lung Health, Glenfield Hospital, Leicester, UK <SUP>2</SUP>Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, UK <SUP>3</SUP>Department of Microbiology, Leicester Royal Infirmary, Leicester, UK <SUP>4</SUP>Department of Infectious Diseases, Leicester Royal Infirmary, Leicester, UK <SUP>5</SUP>Department of Paediatrics and Neonatal Medicine, Leicester Royal Infirmary, Leicester, UK <SUP>6</SUP>Health Protection Agency, East Midlands South Health Protection Unit, Leicester, UK
<SUP>*</SUP>Cosenior authorship for manuscript.
Correspondence to Dr Pranab Haldar, Department of Respiratory Medicine, Glenfield Hospital, Groby Road, Leicester, LE3 9QP, UK; ph62@le.ac.uk
Received 16 August 2011 - Revised 6 August 2012 - Accepted 9 August 2012 - Published Online First 6 September 2012
Abstract
Background
The efffectiveness of tuberculosis (TB) contact screening programmes using interferon γ release assays remains uncertain as prospective contact TB risk is not well characterised.
Objectives
To quantify 2-year TB risk and evaluate screening performance with single-step QuantiFERON TB Gold-In Tube (QFT) in adult contacts. To compare TB risk between QFT tested subgroups stratified by exposure type (smear positive pulmonary (SP) versus non-smear positive (NSP) TB) and age (younger (16?35 years) versus older (≥36 years)).
Methods
Screening involved QFT testing in older contacts of SP and all younger contacts, 8?12 weeks after index notification. Chemoprevention (3RH) was offered to QFT positive (+) younger adults. TB risk was determined in a prospective cohort study.
Results
43 TB events occurred in 1769 adult contacts observed for median 717 days (2-year rate (95% CI)=2?5% (1.7 to 3.2)). Index-contact strain matching was demonstrable for 18 of 22 (82%) paired samples. No contacts (0/98) receiving 3RH developed TB. 215 of 817 appropriately tested adults (26.3%) were QFT+. 14 of 112 untreated QFT+ adults developed TB (2-year rate (95% CI)=13?4% (7.7 to 21.1)). The model required 35 contacts screened with QFT to identify one contact developing TB at 2 years. TB rates were comparable in QFT+ contacts of SP and NSP (rate ratio (RR)=0.98, p=0?962). For QFT+ older contacts, the disease rate was lower (8.9% (3.3 to 19.1)) and similar to the overall group rate (RR=1.4, p=0.503).
Conclusions
QFT based single-step contact screening is effective in young adults.
-<CITE></CITE>
<CITE></CITE>Tuberculosis - Original article
Single-step QuantiFERON screening of adult contacts: a prospective cohort study of tuberculosis risk
Pranabashis Haldar 1,2, Helen Thuraisingam 1, Hemu Patel 3, Nelun Pereira 3, Robert C Free 2, James Entwisle 1, Martin Wiselka 4, Edwyn Wren Hoskyns 5, Philip Monk 6, Michael R Barer 2,3,*, Gerrit Woltmann 1,*
Author Affiliations: <SUP>1</SUP>Department of Respiratory Medicine, Institute for Lung Health, Glenfield Hospital, Leicester, UK <SUP>2</SUP>Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, UK <SUP>3</SUP>Department of Microbiology, Leicester Royal Infirmary, Leicester, UK <SUP>4</SUP>Department of Infectious Diseases, Leicester Royal Infirmary, Leicester, UK <SUP>5</SUP>Department of Paediatrics and Neonatal Medicine, Leicester Royal Infirmary, Leicester, UK <SUP>6</SUP>Health Protection Agency, East Midlands South Health Protection Unit, Leicester, UK
<SUP>*</SUP>Cosenior authorship for manuscript.
Correspondence to Dr Pranab Haldar, Department of Respiratory Medicine, Glenfield Hospital, Groby Road, Leicester, LE3 9QP, UK; ph62@le.ac.uk
Received 16 August 2011 - Revised 6 August 2012 - Accepted 9 August 2012 - Published Online First 6 September 2012
Abstract
Background
The efffectiveness of tuberculosis (TB) contact screening programmes using interferon γ release assays remains uncertain as prospective contact TB risk is not well characterised.
Objectives
To quantify 2-year TB risk and evaluate screening performance with single-step QuantiFERON TB Gold-In Tube (QFT) in adult contacts. To compare TB risk between QFT tested subgroups stratified by exposure type (smear positive pulmonary (SP) versus non-smear positive (NSP) TB) and age (younger (16?35 years) versus older (≥36 years)).
Methods
Screening involved QFT testing in older contacts of SP and all younger contacts, 8?12 weeks after index notification. Chemoprevention (3RH) was offered to QFT positive (+) younger adults. TB risk was determined in a prospective cohort study.
Results
43 TB events occurred in 1769 adult contacts observed for median 717 days (2-year rate (95% CI)=2?5% (1.7 to 3.2)). Index-contact strain matching was demonstrable for 18 of 22 (82%) paired samples. No contacts (0/98) receiving 3RH developed TB. 215 of 817 appropriately tested adults (26.3%) were QFT+. 14 of 112 untreated QFT+ adults developed TB (2-year rate (95% CI)=13?4% (7.7 to 21.1)). The model required 35 contacts screened with QFT to identify one contact developing TB at 2 years. TB rates were comparable in QFT+ contacts of SP and NSP (rate ratio (RR)=0.98, p=0?962). For QFT+ older contacts, the disease rate was lower (8.9% (3.3 to 19.1)) and similar to the overall group rate (RR=1.4, p=0.503).
Conclusions
QFT based single-step contact screening is effective in young adults.
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