The effect of introducing IGRA to screen French healthcare workers for tuberculosis and potential conclusions for the work organisation

Abstract

IntroductionIn France, pre-employment screening for tuberculosis (TB) is performed for healthcare workers (HCW). Screening is repeated when exposure to TB patients or infectious material occurs. The results of these TB screenings were analysed in a retrospective analysis.MethodTuberculin skin tests (TST) and interferon-gamma release assays (QuantiFERON® Gold In-Tube – QFT) were used to perform the TB screenings. The screening results of 637 HCWs on whom QFT was performed were taken from the records of the University Hospital of Nantes.ResultsIn three (0.5%) HCW, the QFT was indeterminate. In 22.2%, the QFT was positive. A second QFT was performed in 118 HCWs. The reversion rate was 42% (5 out of 17). The conversion rate was 6% (6 out of 98). A TST was performed on 466 (73.5%) of the HCWs. Results for TST > 10 mm were 77.4%. In those with a TST < 10 mm, QFT was positive in 14% and in those with a TST ≥ 10 mm, QFT was positive in 26.7%. Depending on the definition for conversion in the QFT, the annual attack rate was 4.1% or 7.3%. X-ray and pneumology consultation was based on positive QFT rather than TST alone (52 out of 56). No active TB was detected.ConclusionThe TST overestimated the prevalence of LTBI in this cohort. The decision about X-ray and consultation regarding preventive treatment should be based on the QFT rather than the TST results. The high reversion rate should be taken into consideration when consulting with HCWs regarding preventive treatment. The high conversion rate seems to indicate that preventive measures such as wearing masks should be improved.

Occupational Screening for Tuberculosis and the Use of a Borderline Zone for Interpretation of the IGRA in German Healthcare Workers

“…A second study in Italian healthcare students found a prevalence of positive TST of 3.8% [24] . We found a lower prevalence rate than a recent French study (22.2%) [25] and a Portuguese study (29.5%) [26] , but higher rates than two studies from Norway [27] and Denmark (3.4% and 1%) [28] , respectively. Moreover, Fong et al observed a prevalence of a positive QFT of 6.6% in the US [29] .…”

“…In contrast to our findings, Rafiza and Rampal observed an increased risk of LTBI for workers in emergency wards [30] and Franchi et al found that TST conversion was associated with working in an obstetric emergency room and ambulatory discharge [31] . Several European HCW studies found no association between positive QFT and workplace [21] , [25] , [32] , [33] . The high rate of positive IGRA (14.2%) in administrative staff seems astonishing, but the occupational physician who was responsible for the decision about the screening saw these employees as being at a certain risk.…”

Mycobacterium tuberculosis nucleic acid amplification tests reduce nosocomial tuberculosis exposure in intensive care units: A nationwide cohort study

“…Nosocomial transmission of PTB is a well‐known risk for outpatients, inpatients, and health‐care workers . With the coincident advent of human immuno‐deficiency virus and multi‐drug‐resistant TB, an outbreak in high‐income country has been reported, in which more than half of exposed patients developed disease and died.…”

Preventive tuberculosis treatment effect on QuantiFERON TB-Gold in-tube testing in a high tuberculosis-endemic country: A clinical trial

“…Whether QFT-GIT is an essential biomarker of preventive treatment efficacy remains controversial (Bastos et al, 2013;Cranmer et al, 2018;Goletti et al, 2018;Goletti et al, 2007;Kabeer et al, 2011;Takenami et al, 2012). In addition, the occurrence of reversion and conversion of IGRA results has been reported in cohort studies of untreated LTBI (Adams et al, 2015;Adetifa et al, 2013;Aichelburg et al, 2014;Andrews et al, 2015;Bartalesi et al, 2013;Chiappini et al, 2012;Lee et al, 2012;Monárrez-Espino et al, 2014;Moucaut et al, 2013;Shu et al, 2016;Uto et al, 2014;Zwerling et al, 2013). Hence, larger-scale trials are required to validate the use of serial QFT-GIT tests for evaluating the efficacy of preventive treatment.…”