scholarly journals Tuberculosis infection screening in children with close contact: a hospital-based study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lin Sun ◽  
Xue Qi ◽  
Yajie Guo ◽  
Hui Qi ◽  
Jieqiong Li ◽  
...  

Abstract Background Identifying and prioritizing at-risk populations is critical for pediatric tuberculosis control. We aimed to identify a latent tuberculosis infection (LTBI) screening strategy that is appropriate for the Chinese context among children with different TB exposure levels and to explore its clinical importance. Methods During 2013–2015, we enrolled hospitalized children with suspected respiratory infectious disease (RID) for LTBI screening using the tuberculin skin test (TST) and interferon-γ release assay (IGRA) T-SPOT.TB as part of a work up for their RID. Participants with confirmed diagnosis were classified into three subgroups according to level of exposure to TB: no reported contact risk, with household contact risk, and with non-household contact risk. Results A total 6202 children (median age: 4.76 years; interquartile range: 1.0–8.0 years) were enrolled. Children with no reported contact risk had the lowest proportions of positive results for the IGRA (0.7%) and TST (3.3%). The proportion of positive results for each test was higher for household contacts than non-household contacts. The TST positive proportion was much higher than that for the IGRA in all three groups. Children with IGRA+/TST+ results had larger indurations than those with IGRA− /TST+  results (15 mm vs. 13 mm, P = 0.02). For IGRA, older age (> 5 years) and non-household or household contact risk were associated with a positive result. Conclusions Positive IGRA results in children with a contact risk can serve as a critical reference for LTBI management. IGRA can be used, in preference to TST, for Chinese children with a TB exposure risk.

2009 ◽  
Vol 30 (6) ◽  
pp. 581-584 ◽  
Author(s):  
Priya Khanna ◽  
Vladyslav Nikolayevskyy ◽  
Fiona Warburton ◽  
Elek Dobson ◽  
Francis Drobniewski

The prevalence of latent tuberculosis infection in a cohort of nurses new to a London hospital was 7.6% (13 of 171), using an interferon-γ(IFN-γ) release assay, and 16.2% (24 of 148), using the tuberculin skin test. On multivariate analysis, birth in a country with tuberculosis prevalence of more than 40 cases per 100,000 population was associated with positive results of both the IFN-γ release assay and the tuberculin skin test.


2008 ◽  
Vol 29 (9) ◽  
pp. 878-886 ◽  
Author(s):  
Nira R. Pollock ◽  
Antonio Campos-Neto ◽  
Suely Kashino ◽  
Danielle Napolitano ◽  
Samuel M. Behar ◽  
...  

Objective.In late 2006, our hospital implemented use of the QuantiFERON-TB Gold (QFT-G) assay, a whole-blood interferon-γ release assay, for detection of tuberculosis infection. All newly hired healthcare workers (HCWs) with positive Mantoux tuberculin skin test (TST) results were routinely tested with the QFT-G assay, to take advantage of its higher specificity. We then undertook a quality assurance review to evaluate the QFT-G test results in HCWs with multiple risk factors for latent tuberculosis infection (LTBI).Methods.The clinical records for TST-positive HCWs tested with the QFT-G assay were reviewed. HCWs with 2 or more risk factors commonly associated with LTBI were classified as “increased risk” (IR). IR HCWs who had negative QFT-G test results underwent repeat QFT-G testing and were offered testing with a different interferon-γ release assay (T-SPOT.TB) and with extended T cell stimulation assays.Results.Ofl43 TST-positive HCWs tested with the QFT-G assay, 26 (18%) had positive results, 115 (81%) had negative results, and 2 (1 %) had indeterminate results. Of 82 IR HCWs, 23 (28%) had positive QFT-G test results, and 57 (70%) had negative results. Of the 57 IR HCWs with negative results, 43 underwent repeat QFT-G testing: 41 had negative results again, and 2 had positive results. These 43 HCWs were also offered additional testing with the T-SPOT.TB diagnostic, and 36 consented: 31/36 tested negative, and 5/36 tested positive. Extended assays using the antigens ESAT-6 and CFP-10 confirmed the positive results detected by the overnight assays and yielded positive results for an additional 7/36 (19%) of individuals; strikingly, all 36 HCWs had strongly positive test results with assays using purified protein derivative.Conclusions.The extreme discordance between the results of our clinical diagnostic algorithm and the results of QFT-G testing raises concern about the sensitivity of the QFT-G assay for detection of LTBI in our HCWs. Results of extended stimulation assays suggest that many of our IR HCWs have indeed been sensitized to Mycobacterium tuberculosis. It is possible that the QFT-G assay identifies those at higher reactivation risk rather than all previously infected, but, in the absence of long-term follow-up data, we should interpret negative QFT-G results with some caution.


2020 ◽  
Author(s):  
Roxana Ghanaie ◽  
Abdollah Karimi ◽  
Leila Azimi ◽  
Seddon James ◽  
Mahshid Nasehi ◽  
...  

Abstract Background: Although the World Health Organization has recommended the diagnosis and prophylactic treatment of latent tuberculous infection (LTBI) in child household contacts of tuberculosis (TB) cases, the national programs in high-burden TB regions rarely implement adequate screening of this high-risk group, mainly because of resource limitations. We aimed to evaluate the prevalence of LTBI among pediatric household contacts of TB cases in two high-burden provinces in Iran.Methods: We conducted a cohort study in children who had been in household contact with a TB index. All subjects were assessed for active disease through evaluation of symptoms and if active disease was suspected were investigated by chest radiograph and bacilli detection in sputum or nasogastric lavage. For LTBI diagnosis, tuberculin skin test (TST) and QuantiFERON®-TB Gold Plus (QFT-Plus) were performed at the time of the index TB case diagnosis, as well as, 3, 12, and 18 months, if the first results were negative. In addition, interferon-γ-induced protein-10 (IP-10) concentrations were measured in QFT-Plus supernatants for all participants. Results: A total of 230 children were enrolled, who had contact with an index TB case. Three contacts were diagnosed with active TB. According to the TST/QFT-Plus results, 104 (45.2%) children were identified with LTBI during our study.Conclusion: This study alarmingly illustrates a high prevalence of LTBI among Iranian children exposed to TB cases. We, therefore, emphasize that the children living in close contact with an infectious TB case should be screened effectively and receive prophylactic therapy.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 857.1-857
Author(s):  
C. Pávez Perales ◽  
A. Quiles Roger ◽  
E. Grau García ◽  
M. De la Rubia Navarro ◽  
S. Leal Rodriguez ◽  
...  

Background:Patients with rheumatic diseases (RD) are at higher risk of latent tuberculosis infection (LTBI) reactivation. To detect and treat it before starting treatment, especially with biological therapies, decrease the reactivation risk. Diagnosis is carried out by the tuberculin skin test (TST) or interferon-gamma release assays (IGRAs), IGRAs might be more specific and sensitive.Objectives:We aim to analyze the concordance between QuantiFERON-TB Gold In-Tube (QTF) and TST for the diagnosis of LTBI in patients with rheumatic diseases.Methods:A retrospective observational study was conducted including patients diagnosed with RD screened for LTBI with both TST and QTF (2014-2018). Demographical and clinical variables at screening and at follow-up were collected. The concordance between both tests has been estimated as categorical variables using Cohen´s Kappa test, considering “poor” if it is ≤ 0,20; “low” if 0,20 < k ≤ 0,40, “moderate” if 0,40 < k ≤ 0,60, “substantial” if 0,60 < k ≤ 0,80 and “optimal” if k > 0,80.Results:167 patients were included (57% women) with a mean age of 52±16 years. 42% of them had systemic autoimmune diseases, 22% spondyloarthropathies and 36% other RD. 2 had history of past active tuberculosis (TB). At the time of screening, 46.11% were treated with GC.LTBI was diagnosed in 35 patients: 15 had both QTF and TST positive, 16 only QTF positive and 4 only TST positive. 12 from 31 QTF positive patients were treated with GC at the time of screening. 3 from 19 TST positive patients were treated with GC at the time of screening.After LTBI screening 62 patients received biological treatment, 4 of them had both test positive, 6 only QTF positive and 2 only TST positive. 11 received LTBI treatment according to the hospital protocol (isoniazid for 6 to 9 months). 10 completed treatment, 1 did not because of intolerance and did not receive other treatment. 1 patient with only TST positive was considered a false positive and did not receive treatment. During follow-up no TB reactivation was reported.23 patients with LBTI received treatment other than biological therapy during follow-up, of them 8 received LBTI treatment. There was no TB reactivation during follow up.The Kappa concordance between QTF and TST was estimated: moderated in the whole sample, poor in the patients treated with GC at screening, and substantial when the patients treated with GC at screening were excluded. Results are shown in Table 1.Table 1.Kappa concordance between QTF and TST.Conclusion:QTF seems to be the most appropriate LTBI screening test in patients with RD treated with GC. Screening and treatment of LTBI in patients with RD treated with or without biological agents was effective in reducing TB reactivation.Disclosure of Interests:None declared.


Author(s):  
Kileen L. Shier

Interferon-gamma release assays are used to screen various patient populations for latent tuberculosis infection. In this issue of the Journal of Clinical Microbiology, Ward et al. (J Clin Microbiol 59:e00811-21, 2021, https://doi.org/10.1128/JCM.00811-21 ) investigated an increased indeterminate rate in the QuantiFERON-TB Gold Plus assay among COVID-19 patients that was independent of immunosuppressive agents and lymphopenia. In their study, COVID-19 patients with indeterminate QuantiFERON-TB Gold Plus results trended toward decreased survival as well as increased serum IL-6 and IL-10 levels, though the differences were not statistically significant. They suggest that this pattern of cytokine expression supports an impairment of Th1, and specifically interferon-γ production, in critically ill COVID-19 patients, as indicated by indeterminate QuantiFERON-TB Gold Plus results. Clinicians should be aware of the increased rate of indeterminate QuantiFERON-TB Gold Plus results in critically ill COVID-19 patients.


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