TY - JOUR
T1 - The role of the Interferon gamma release assay in assessing recent tuberculosis transmission in a hospital incident
AU - Bradshaw, Louise
AU - Davies, Elizabeth
AU - Devine, Michael
AU - Flanagan, Peter
AU - Kelly, Paul
AU - O'Connor, Kevin
AU - Drobniewski, Francis
AU - Nikolayevskyy, Vladislav
AU - Abubakar, Ibrahim
N1 - © 2011 Bradshaw et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
PY - 2011/6/13
Y1 - 2011/6/13
N2 - In 2007, an extensive contact screening investigation into onward transmission of tuberculosis was instigated at a hospital in Northern Ireland following diagnosis of pulmonary multi-drug resistant TB in a healthcare worker. Interferon gamma release assays (IGRAs) were used to test 333 patients and 98 staff. We investigated for evidence of onward transmission and recent infection based on analysis of clinical, demographic and IGRA data. We also described within-patient variability of IGRA results. Among patients and staff, increasing age of patients was the only factor associated with IGRA positivity. Greatest within-subject variability of IU/mL in serially-tested patients/staff was seen in those with a positive IGRA test and this did not correlate with increased exposure to the index case. IGRA positivity being largely explained by increasing age in patients and previous TB contact in staff lends weight to the conclusion that IGRA positivity reflected previous infection rather than recent transmission.
AB - In 2007, an extensive contact screening investigation into onward transmission of tuberculosis was instigated at a hospital in Northern Ireland following diagnosis of pulmonary multi-drug resistant TB in a healthcare worker. Interferon gamma release assays (IGRAs) were used to test 333 patients and 98 staff. We investigated for evidence of onward transmission and recent infection based on analysis of clinical, demographic and IGRA data. We also described within-patient variability of IGRA results. Among patients and staff, increasing age of patients was the only factor associated with IGRA positivity. Greatest within-subject variability of IU/mL in serially-tested patients/staff was seen in those with a positive IGRA test and this did not correlate with increased exposure to the index case. IGRA positivity being largely explained by increasing age in patients and previous TB contact in staff lends weight to the conclusion that IGRA positivity reflected previous infection rather than recent transmission.
U2 - 10.1371/journal.pone.0020770
DO - 10.1371/journal.pone.0020770
M3 - Article
SN - 1932-6203
VL - 6
JO - PLoS One
JF - PLoS One
IS - 6
M1 - e20770
ER -