• Tuberculosis and Respiratory Diseases
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• v.68 no.5
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• pp.280-285
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• 2010

Background: $QuantiFERON^{(R)}$-TB Gold In Tube (QFT-G IT) has been used for diagnosing latent tuberculosis infection and active tuberculosis (TB) since 2007. However, there has not been enough data on QFT-G IT for universal use in children. In this study, we evaluated the clinical usefulness of the QFT-G IT in pediatric practice. Methods: We retrospectively reviewed the clinical records of 70 patients younger than 18 years of age who had taken QFT-G IT and had a tuberculin skin test (TST) between July 2007 and July 2009 at Wonju Christian Hospital. The subjects were divided into two groups, asymptomatic TB exposure group and disease group. Four patients who were taking immunosuppressants during the study period were excluded. Results: A total of 66 immunocompetent children were included in this study. Among 27 asymptomatic children who had contact histories of TB, 6 (22.2%) were found to be positive by QFT-G IT. Eleven (40.7%) and 5 (18.5%) children were found to be positive by TST with cutoff values of ${\geq}5mm$ and ${\geq}10mm$, respectively. Agreement was fair to good between QFT-G IT and TST (${\kappa}=0.59$: cutoff value ${\geq}5mm$, ${\kappa}=0.7$: cutoff value ${\geq}10mm$). In disease group, 14 patients (35.9%) were diagnosed with active tuberculosis, 8/14 (57.1%) were positive on TST and 9/14 (64.3%) on QFT-G IT. The positive rate of acid-fast bacilli smear, TB-polymerase chain reaction, and culture for tuberculosis was 11% (1/9), 27.3% (3/11) and 33.3% (3/9), respectively. Conclusion: Our data support that the QFT-G IT can be used as an additional diagnostic tool for latent and active tuberculosis infection in children.

• Korean journal of aerospace and environmental medicine
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• v.31 no.3
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• pp.77-81
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• 2021

Purpose: The United States of America have pre-migration screening program are mandated through legislation. The one of purpose of this program is to prevent the importation of certain communicable diseases. Examinations of migration applicants are performed by panel physicians who are licensed physicians in the countries of origin that have agreements with the government departments of the country of destination to undertake this activity. In recent decades, the number of US migrants has increased, however COVID-19 impacted this trend of international migrants. The Aim of this study is to examine trends of US applicants and outcomes of tuberculosis and sexual transmitted infections (STIs) screening in South Korean applicants for US visa. Methods: A total of 4,442 applicants participated in US visa health check-up in 2016 to 2020. Results: The numbers of applicant for US visa in males and females was 1,814 and 2,628. The positive results in tuberculosis and STIs screening was noted with 0.66% in nontuberculous mycobacteria (NTM), 0.03% in tuberculosis, 0.03% in gonorrhea, 0.08% in syphilis, and 0.74% in chlamydia. The age groups of 2 to 14 years showed higher positive rate (13.89%) in tuberculin skin test (TST) tests compared to the rate of interferon gamma release assay (IGRA) tests (0.44%, P<0.001). The positive ratio of NTM and abnormal chest X-ray (CXR) which required sputum tests among the applicants over 15 years old has trends to increase with age. The age groups of over 70 years showed high positive rate in NTM and abnormal CXR (4.10%, 20.51%). However, ages 15 to 49 years groups showed 0.00% to 0.30% in NTM and 1.08% to 3.91% in abnormal CXR. In the study population, the positive rates of STIs were 0.03%, 0.08%, and 0.74% in gonorrhea, syphilis, and chlamydia, respectively. Among the participants who underwent sputum smears and cultures were just 1 case of active tuberculosis (0.03%) and 25 cases of NTM infection (0.66%). Conclusion: This study found that rate of positivity in tuberculosis and STIs screening among South Korean applicants for US visa in 2016 to 2020. Regarding tuberculosis, the positivity of CXR among the aged 15 to 59 years applicants was lower than that among over 60 years old. Among 2 to 14 years, positivity of IGRA was very low. And IGRA test can reduce effort of further evaluation compared to TST test in South Korea, so IGRA test among young adults can be useful. High positive rates in STI among young adult could result in high active sexuality, especially chlamydia infection is most common. Therefore Chlamydia polymerase chain reaction should be considered formal protocol among the Korean applicant for US visa.

• Pediatric Infection and Vaccine
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• v.15 no.2
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• pp.174-179
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• 2008

Purpose : The purpose of this study was to investigate the clinical features of adolescent TB. Methods : We retrospectively reviewed the medical records of the adolescents aged 12 to 18 years and who are hospitalized with the diagnosis of TB at Dong Kang General Hospital between January 2003 and December 2007. Results : Of the 29 patients who were identified, 65.5% were male. The median age at diagnosis was 16.9 years (range: 12.1-18.9 years). A tuberculin skin test (TST) was performed for 6 patients (20.7%). Among them, 5 (5 of 8[62.5%]) in the 12-15 years age group (Group A) and 1 (1 of 21[4.8%]) in the 16-18 years of age group (Group B) were TST positive, which showed that the TST performing rate decreased with age (P<0.01). Twenty-five patients (86.2%) were detected by evaluating the clinical symptoms that suggested TB and 4 patients (13.8%) were detected by screening, but no cases were detected by contact tracing. Twenty patients (69.0%) had isolated pulmonary disease. Seven patients (24.1%) had pulmonary and extrapulmonary disease and 2 patients (6.9%) had exclusively extrapulmonary disease. Most patients presented with multiple symptoms, and the most common were cough (79.3%), fever (75.9%), sputum (65.8%) and chest pain (34.5%). M. tuberculosis was isolated from the sputum of 20 patients (69.0%). The culture-positive rate increased with age (range: 62.5% in Group A to 71.4% in Group B), but the difference between the groups was not significant. Cavitary lesions were found 13 patients (44.8%). The cavitary lesion rate increased with age (range: 25.0% in Group A to 52.4% in Group B), but the difference between the groups was not significant. Four patients (13.8%) were lost during follow-up. One patient (6.9%) relapsed. Conclusion : Clinicians need to be aware of the unique features of adolescent TB, and they also need awareness of the importance of TST and contact investigation for an adult suspected of having TB for making the diagnosis of TB.

• Pediatric Infection and Vaccine
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• v.18 no.1
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• pp.48-53
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• 2011

Purpose : Early diagnosis of active tuberculosis (TB) in children is difficult. The widely used tuberculin skin test has low sensitivity and cross reactivity with non-tuberculous mycobacteria or Bacille Calmette-Gu$\acute{e}$rin vaccination. Interferon gamma release assays have been shown good diagnostic accuracy for active in adults. But studies in children were limited. The purpose of this study was to examine the performance of enzyme-linked immunospot assay (ELISpot) as an initial test in the diagnosis of active tuberculosis in children. Methods : In a hospital-based study, we prospectively examined the performance of ELISPot in 33 children suspected of active TB. TB was confirmed bacteriologically or histologically. Results : Among 33 patients, 9 had active tuberculosis. When tested, they all had a positive test result from the ELISpot. The sensitivity and specificity of the assay were 100% (95% CI, 66.4-100%) and 95.8% (95% CI, 78.9-99.9%) respectively. Conclusion : ELISpot might be an useful and improved clinical diagnostic method for the detection of active TB in children.

• Biomedical Science Letters
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• v.19 no.2
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• pp.90-97
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• 2013

The tuberculin skin test (TST) and interferon gamma (IFN-${\gamma}$) release assay (IGRA) have been widely used for diagnosis of latent tuberculosis infection (LTBI). In order to overcome limitations of current LTBI diagnostic methods, the development of a novel molecular assay which is able to measure the IFN-${\gamma}$ messenger RNA (mRNA) expression level after stimulation with Mycobacterium tuberculosis (MTB) specific antigen was recently developed. The ability of a molecular assay to detect MTB infection was similar to commercial IGRA however, the optimal incubation time for stimulating IFN-${\gamma}$ was not yet established. Therefore, in this study the direct comparisons of MTB Ag stimulation times (4 and 24 hrs) were performed for diagnosis of MTB infection. Data showed that the coincident rate between QFT-GIT IFN-${\gamma}$ ELISA and IFN-${\gamma}$ RT-PCR (4 hrs) was 88.35% and that of QFT-GIT and IFN-${\gamma}$ RT-PCR (24 hrs) was 70.85%. Based on a receiver operating characteristic (ROC) curve, the 4 hrs-MTB specific Ag stimulation time for IFN-${\gamma}$ RT-PCR had the significant P value, 95% CI value, and AUC (P < 0.0001, 95% CI=0.82 to 1.02, and AUC=0.9214) in comparison with 24 hrs-MTB specific Ag stimulation time (P = 0.009, 95% CI=0.06 to 0.94, and AUC=0.7711). These results show that 4-hr was the most optimal MTB Ag stimulation time for performing IFN-${\gamma}$ RT-PCR. Although semi-quantitative RT-PCR had a few analytical limitations, it might be useful as an alternative molecular diagnostic method for detecting MTB infection.