-
Journal of Infection in Developing... Aug 2018Mantoux test aids in the diagnosis of tuberculosis (TB), however its application and interpretation are dependent on multiple factors. (Observational Study)
Observational Study
INTRODUCTION
Mantoux test aids in the diagnosis of tuberculosis (TB), however its application and interpretation are dependent on multiple factors.
METHODOLOGY
A prospective study enrolling 400 children (aged 2-12) suspected to have tuberculosis. All participants received Mantoux test with two different strengths (1 TU and 5 TU) of Purified Protein Derivative (PPD) on different forearms. The test was read by two readers after 48 ± 2 and 72 ± 2 hours. Primary outcome was difference in the size of induration when read by two readers (interobserver variability). Secondary outcomes were difference in the size of induration at different intervals, with different strengths of PPD and percentage positivity of Mantoux test in TB patients.
RESULTS
Statistically significant difference was seen in the size of induration when read by two different readers, with fair to moderate agreement when read at 48 and 72 hours (1 TU: p = 0.002, k = 0.52 and p = 0.1, k = 0.73 respectively, 5 TU: p = 0.001, k = 0.39 and p = 0.0009, k = 0.33 respectively). Tendency of under-reading occurred when size of induration was close to significant level (10-14 mm). Size of induration was similar when read at 48 or 72 hours (1 TU: p = 0.9, 5 TU: p = 1.0). Mantoux positivity rate in patients with TB was more with 5 TU as compared to 1 TU (61.2% vs. 16.3%).
CONCLUSIONS
There is significant interobserver variability with a tendency to under-read around the cutoff point. The use of 5 TU PPD at 48 hours by a trained physician can aid in early and more reliable diagnosis of TB.
Topics: BCG Vaccine; Child; Child, Preschool; Female; Humans; Male; Observer Variation; Prospective Studies; Tuberculin Test; Tuberculosis; Tuberculosis, Meningeal; Tuberculosis, Pulmonary
PubMed: 31958324
DOI: 10.3855/jidc.9601 -
International Journal of... 2022Pregnant women who live in tuberculosis (TB)-affected households are more likely to develop latent TB infection (LTBI), which often escapes treatment. This study aims to...
BACKGROUND
Pregnant women who live in tuberculosis (TB)-affected households are more likely to develop latent TB infection (LTBI), which often escapes treatment. This study aims to determine if Interferon-gamma release (IGRA) is reliable in screening for LTBI in pregnant women, compare to the tuberculin skin test (TST).
METHODS
It was a cross-sectional study that involved 60 pregnant women with TB contact history as a proxy for LTBI and 30 pregnant women without contact history. Latent TB was detected using the TST 5 tuberculin units and IGRA using the QuantiFERON Gold Plus TB Test kit (QFT-Plus). The sensitivity and specificity of the two diagnostic methods and the agreement between them were estimated using SPSS version 20.0.
RESULTS
The sensitivity 95% (95% confidence interval [CI]: 86.08%-98.96%) and specificity 26.7% (95% CI: 12.28%-45.89%) of TST were compared to that of the IGRA with 60% (95% CI: 46.54%-72.44%) and 73.3% (95% CI: 54.11%-87.72%) sensitivity and specificity, respectively in detecting LTBI in pregnancy. Although there was a significant difference (P < 0.05) between TST and IGRA, the agreement was fair (kappa 0.39; 95% CI: 0.24-0.45).
CONCLUSION
TST assay is more sensitive than IGRA; however, the specificity of IGRA was superior to the TST method. In this study, a fair agreement of TST and IGRA was observed for detecting latent TB infection in pregnant women with household contact with TB patients.
Topics: Humans; Female; Pregnancy; Tuberculin Test; Interferon-gamma Release Tests; Latent Tuberculosis; Cross-Sectional Studies; Tuberculosis; Interferon-gamma
PubMed: 36510919
DOI: 10.4103/ijmy.ijmy_112_22 -
Pulmonology 2021Screening for latent tuberculosis infection (LTBI) in close contacts of infectious TB cases might include Tuberculin Skin Test (TST) and Interferon-Gamma Release Assays... (Review)
Review
INTRODUCTION AND OBJECTIVES
Screening for latent tuberculosis infection (LTBI) in close contacts of infectious TB cases might include Tuberculin Skin Test (TST) and Interferon-Gamma Release Assays (IGRA), in combination or as single-tests. In Portugal, the screening strategy changed from TST followed by IGRA to IGRA-only testing in 2016. Our objective was to compare the cost-effectiveness of two-step TST/IGRA with the current IGRA-only screening strategy in immunocompetent individuals exposed to individuals with respiratory TB.
MATERIALS AND METHODS
We reviewed clinical records of individuals exposed to infectious TB cases diagnosed in 2015 and 2016, in two TB outpatient centers in the district of Porto. We estimated medical, non-medical and indirect costs for each screening strategy, taking into account costs of tests and health care personnel, travel distance from place of residence to screening site and employment status. We calculated the incremental cost-effectiveness ratio (ICER) as the cost difference between the two screening strategies with the difference number of LTBI diagnosis as a measure of cost-effectiveness, assuming that treating LTBI is a cost-effective intervention. We also calculated adjusted odds-ratios to test the association between diagnosis of LTBI and screening strategy and estimated the total cost for averting a potential TB case.
RESULTS
We compared 499 contacts TST/IGRA screened with 547 IGRA-only. IGRA-only strategy yielded a higher screening effectiveness for diagnosing latent tuberculosis infection (aOR 2.12, 95%CI: 1.53 - 2.94). ICER was €106 per LTBI diagnosis, representing increased effectiveness with a slightly increased cost of IGRA-only screening strategy.
CONCLUSIONS
Our data suggests that in Portugal LTBI screening with IGRA-only is more cost-effective than the two-step TST/IGRA testing strategy, preventing a higher number of cases of TB cases.
Topics: Cost-Benefit Analysis; Health Care Costs; Humans; Interferon-gamma Release Tests; Latent Tuberculosis; Mass Screening; Portugal; Tuberculin Test
PubMed: 34053903
DOI: 10.1016/j.pulmoe.2021.04.002 -
Epidemiology and Infection Jan 2019The single intradermal comparative cervical tuberculin (SICCT) test and post-mortem examination are the main diagnostic tools for bovine tuberculosis (bTB) in cattle in...
Test characteristics of the tuberculin skin test and post-mortem examination for bovine tuberculosis diagnosis in cattle in Northern Ireland estimated by Bayesian latent class analysis with adjustments for covariates.
The single intradermal comparative cervical tuberculin (SICCT) test and post-mortem examination are the main diagnostic tools for bovine tuberculosis (bTB) in cattle in the British Isles. Latent class modelling is often used to estimate the bTB test characteristics due to the absence of a gold standard. However, the reported sensitivity of especially the SICCT test has shown a lot of variation. We applied both the Hui-Walter latent class model under the Bayesian framework and the Bayesian model specified at the animal level, including various risk factors as predictors, to estimate the SICCT test and post-mortem test characteristics. Data were collected from all cattle slaughtered in abattoirs in Northern Ireland in 2015. Both models showed comparable posterior median estimation for the sensitivity of the SICCT test (88.61% and 90.56%, respectively) using standard interpretation and for post-mortem examination (53.65% and 53.79%, respectively). Both models showed almost identical posterior median estimates for the specificity (99.99% vs. 99.80% for SICCT test at standard interpretation and 99.66% vs. 99.86% for post-mortem examination). The animal-level model showed slightly narrower posterior 95% credible intervals. Notably, this study was carried out in slaughtered cattle which may not be representative for the general cattle population.
Topics: Animals; Autopsy; Bayes Theorem; Cattle; Diagnostic Tests, Routine; Latent Class Analysis; Northern Ireland; Sensitivity and Specificity; Tuberculin Test; Tuberculosis, Bovine
PubMed: 31364540
DOI: 10.1017/S0950268819000888 -
Frontiers in Public Health 2022Diabetes mellitus (DM) patients with latent tuberculosis infection (LTBI) have an increased risk of developing active tuberculosis (TB) due to impaired immunity. The...
Serial testing of latent tuberculosis infection in patients with diabetes mellitus using interferon-gamma release assay, tuberculin skin test, and creation tuberculin skin test.
BACKGROUND
Diabetes mellitus (DM) patients with latent tuberculosis infection (LTBI) have an increased risk of developing active tuberculosis (TB) due to impaired immunity. The performance of currently available immune response-based assays for identification of TB infection had been rarely evaluated in patients with type 2 DM (T2DM) in China.
METHODS
A prospective study was conducted to investigate the status of LTBI in patients with confirmed T2DM. At the baseline survey, the prevalence of LTBI was tested using interferon-gamma release assay (IGRA), tuberculin skin test (TST) and creation tuberculin skin test (C-TST) in parallel. After a 3-month interval, the participants were retested by the three assays to estimate their performance in the serial testing.
RESULTS
A total of 404 participants with T2DM were included in the study. At baseline, after excluding active TB, the prevalence of LTBI identified by TST (≥ 10 mm), C-TST (≥ 5 mm) and IGRA (≥ 0.35 IU/ml) were 9.65% (39/404), 10.40% (42/404) and 14.85% (60/404), respectively. The concordance of TST and C-TST results with IGRA results was 86.39% (349/404) and 92.08% (372/404) with a Kappa coefficient of 0.37 [95% confidence interval (CI): 0.24- 0.50] and 0.64 (95% CI: 0.53- 0.76), respectively. After a 3-month interval, the continuous results of TST, C-TST and IGRA were observed to be increased with testing conversion for 50, 26 and 27 patients, respectively. For TST and C-TST conversions, the distribution of their quantitative results in serial tests varied significantly when further classified by baseline IGRA dichotomous results.
CONCLUSION
In studied patients with T2DM, C-TST showed higher consistency with IGRA as compared to TST. The present of conversion observed in serial testing suggested that boosting effect of skin testing should be considered for identify of LTBI in patients with T2DM.
Topics: Humans; Interferon-gamma Release Tests; Tuberculin Test; Latent Tuberculosis; Prospective Studies; Diabetes Mellitus, Type 2
PubMed: 36530654
DOI: 10.3389/fpubh.2022.1025550 -
Journal of Ayub Medical College,... 2018Childhood Tuberculosis remains one of the major public health concerns in developing countries like Pakistan and is responsible for high rates of morbidity and mortality...
BACKGROUND
Childhood Tuberculosis remains one of the major public health concerns in developing countries like Pakistan and is responsible for high rates of morbidity and mortality in children. Although tuberculin skin test is very commonly used by physicians all over the world, its interpretation always remains difficult and challenging. The objective of this study was to determine the frequency of positive tuberculin skin test in vaccinated and unvaccinated children suffering from tuberculosis.
METHODS
This Cross-sectional study was conducted in the department of Paediatric Ayub Teaching Hospital, Abbottabad from 1st February 2015 to 30th April 2016. A total of 150 patients were observed in this study. Children of either gender who were aged 1-15 years admitted in ward with tuberculosis were included in the study by using nonprobability convenient sampling technique. We injected 0.1 ml (10 units) of tuberculin purified protein derivative (PPD) into the anterior surface of the forearm and induration was read at 72 hours after administration. Data was entered and analysed using SPSS version 10.
RESULTS
Out of 150 children, 84 (56%) were males and 66 (44%) were females. The mean age was 7.8±3.84 years. Of these 75 (50%) were vaccinated and 75 (50%) were unvaccinated. In vaccinated Group 5.3% children had positive tuberculin skin test while in unvaccinated Group 2.7% children had positive tuberculin skin test and this difference was found statistically insignificant (pvalue= 0.40). Pulmonary TB was the diagnosis in 67 (44.7%), TBM in 65 (43.3%), abdominal TB in 7 (4.7%), disseminated TB in 4 (2.7%) and military TB in 7 (4.7%) patients.
CONCLUSIONS
The positivity of tuberculin skin test in vaccinated and unvaccinated children suffering from tuberculosis was found to be insignificant in our study. We conclude that Tuberculin Skin Test should not be used as a sole diagnostic tool for diagnosing the disease in children of our region..
Topics: Adolescent; Child; Child, Preschool; Cross-Sectional Studies; Female; Humans; Infant; Male; Pakistan; Tuberculin; Tuberculin Test; Tuberculosis; Tuberculosis Vaccines; Vaccination
PubMed: 30632330
DOI: No ID Found -
The Korean Journal of Internal Medicine May 2017The tuberculin skin test (TST) and interferon γ release assay are currently used as diagnostic tools to detect latent tuberculosis (TB) infection; however, there are... (Comparative Study)
Comparative Study
BACKGROUND/AIMS
The tuberculin skin test (TST) and interferon γ release assay are currently used as diagnostic tools to detect latent tuberculosis (TB) infection; however, there are inconsistencies about the degree of agreement between the tests. We aimed to evaluate the concordance rate between the two tests in household contacts of a country with intermediate TB burden, where most people were vaccinated.
METHODS
We recruited household contacts who spent > 8 hours daily with patients with microbiologically confirmed active pulmonary TB, and received both TST and T-SPOT.TB (Oxford Immunotec) simultaneously. The degree of agreement was analysed according to TST cutoff and Bacille Calmette-Guerin (BCG) vaccination status. Relevant factors were analysed to establish the association with TST or T-SPOT.TB.
RESULTS
Among 298 household contacts, 122 (40.9%) were spouses, and 250 (83.9%) had received BCG vaccination. In the contact sources, 117 (39.3%) showed a positive result for acid-fast bacillus (AFB) sputum smear and 109 (36.6%) had cavities. The highest agreement rate of 69.5% and κ value of 0.378 were found with a 10 mm cutoff. Spouse, time interval from TB diagnosis to test, and AFB sputum smear positivity were significantly associated with a positive result for T-SPOT.TB. Sex, BCG vaccination, and cavity on chest computed tomography were related to TST positivity.
CONCLUSIONS
The present study suggested it was not possible for TST and T-SPOT.TB to replace each other because of considerable discrepancy between the two tests in household contacts in a country with intermediate TB prevalence.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Female; Humans; Interferon-gamma Release Tests; Latent Tuberculosis; Male; Middle Aged; Retrospective Studies; Tuberculin Test; Young Adult
PubMed: 28111432
DOI: 10.3904/kjim.2015.344 -
Epidemiology and Health 2016The tuberculin skin test (TST) and the QuantiFERON-TB Gold test (QFT) are used to identify latent tuberculosis infections (LTBIs). The aim of this study was to determine... (Comparative Study)
Comparative Study
OBJECTIVES
The tuberculin skin test (TST) and the QuantiFERON-TB Gold test (QFT) are used to identify latent tuberculosis infections (LTBIs). The aim of this study was to determine the agreement between these two tests among health care workers in Iran.
METHODS
This cross-sectional study included 177 tuberculosis (TB) laboratory staff and 67 non-TB staff. TST indurations of 10 mm or more were considered positive. The Student's t-test and the chi-square test were used to compare the mean score and proportion of variables between the TB laboratory staff and the non-TB laboratory staff. Kappa statistics were used to evaluate the agreement between these tests, and logistic regression was used to assess the risk factors associated with positive results for each test.
RESULTS
The prevalence of LTBIs according to both the QFT and the TST was 17% (95% confidence interval [CI], 12% to 21%) and 16% (95% CI, 11% to 21%), respectively. The agreement between the QFT and the TST was 77.46%, with a kappa of 0.19 (95% CI, 0.04 to 0.34).
CONCLUSIONS
Although the prevalence of LTBI based on the QFT and the TST was not significantly different, the kappa statistic was low between these two tests for the detection of LTBIs.
Topics: Adult; Cross-Sectional Studies; Female; Health Personnel; Humans; Interferon-gamma Release Tests; Iran; Latent Tuberculosis; Male; Middle Aged; Sensitivity and Specificity; Tuberculin Test; Young Adult
PubMed: 27457062
DOI: 10.4178/epih.e2016032 -
BMC Veterinary Research Jan 2022Caprine tuberculosis (TB) is a zoonosis caused by members of the Mycobacterium tuberculosis complex (MTBC). Caprine TB control and eradication programmes have...
BACKGROUND
Caprine tuberculosis (TB) is a zoonosis caused by members of the Mycobacterium tuberculosis complex (MTBC). Caprine TB control and eradication programmes have traditionally been based on intradermal tuberculin tests and slaughterhouse surveillance. However, this strategy has limitations in terms of sensitivity and specificity. Different factors may affect the performance of the TB diagnostic tests used in goats and, subsequently, the detection of TB-infected animals. In the present study, the effect of two of the factors that may affect the performance of the techniques used to diagnose TB in goats, the topical administration of corticosteroids and a recent pre-sensitisation with tuberculin, was analysed.
METHODS
The animals (n = 151) were distributed into three groups: (1) a group topically treated with corticosteroids 48 h after intradermal tuberculin tests (n = 53); (2) a group pre-sensitised with bovine and avian purified protein derivatives (PPDs) 3 days before the intradermal tuberculin test used for TB diagnosis (n = 48); and (3) a control group (n = 50). All the animals were tested using single and comparative intradermal tuberculin (SIT and CIT, respectively) tests, an interferon-gamma release assay (IGRA) and a P22 ELISA.
RESULTS
The number of SIT test reactors was significantly lower in the group treated with corticosteroids when compared to the pre-sensitised (p < 0.001) and control (p = 0.036) groups. In contrast, pre-sensitisation with bovine and avian PPDs did not cause a significant reduction in the number of SIT and CIT test reactors compared with the control group. In fact, a higher number of reactors was observed after the prior tuberculin injection in the pre-sensitised group (p > 0.05). No significant effect was observed on IGRA and P22 ELISA due to corticosteroids administration. Nevertheless, a previous PPD injection affected the IGRA performance in some groups.
CONCLUSIONS
The application of topical corticosteroid 24 h before reading the SIT and CIT tests can reduce the increase in skin fold thickness and subsequently significantly decrease the number of positive reactors. Corticosteroids used can be detected in hair samples. A previous pre-sensitisation with bovine and avian PPDs does not lead to a significant reduction in the number of intradermal tests reactors. These results are valuable in order to improve diagnosis of caprine TB and detect fraudulent activities in the context of eradication programs.
Topics: Administration, Topical; Adrenal Cortex Hormones; Animals; Cattle; Cattle Diseases; Goat Diseases; Goats; Sensitivity and Specificity; Tuberculin; Tuberculin Test; Tuberculosis
PubMed: 35086534
DOI: 10.1186/s12917-022-03156-0 -
Frontiers in Immunology 2021Tuberculosis (TB) remains a worldwide problem. Despite the high disease rate, not all who are infected with () develop disease. Interferon-γ (IFN-γ) specific T cell... (Review)
Review
Tuberculosis (TB) remains a worldwide problem. Despite the high disease rate, not all who are infected with () develop disease. Interferon-γ (IFN-γ) specific T cell immune assays such as Quantiferon and Elispot, as well as a skin hypersensitivity test, known as a tuberculin skin test, are widely used to infer infection. These assays measure immune conversion in response to . Some individuals measure persistently negative to immune conversion, despite high and prolonged exposure to . Increasing interest into this phenotype has led to multiple publications describing various aspects of these responses. However, there is a lack of a unified "resister" definition. A universal definition will improve cross study data comparisons and assist with future study design and planning. We review the current literature describing this phenotype and make recommendations for future studies.
Topics: Global Health; Humans; Interferon-gamma Release Tests; Mycobacterium tuberculosis; Phenotype; Population Surveillance; Tuberculin Test; Tuberculosis
PubMed: 33717116
DOI: 10.3389/fimmu.2021.619988