• Korean Journal of Veterinary Service
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• v.33 no.4
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• pp.335-340
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• 2010

On the basis of the 2009 business plan, 20,394 Korean native cattle and beef cattle were carried examination of bovine tuberculosis by using ELISA technique from March to December. As a result, 66 cattle tested positive for tuberculosis and showed 0.32% positive ratio. Intradermal tuberculin test about 66 cases of ELISA positive cattle was carried out, and all of 66 cattle were confirmed as negative. However, when 7 PPD-positive cattle derived from slaughterhouse were tested by 20k ELISA kit and MS ELISA kit, 3 (2 suspect) cattle and 5 cattle showed positive results, respectively. As compared to the results of PPD test, the concordance rates were 43% (71% included suspect) with 20k ELISA kit and 71% with MS ELISA kit.

• Korean Journal of Veterinary Service
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• v.32 no.2
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• pp.119-124
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• 2009

The epidemiological survey of mass outbreak region of bovine tuberculosis from January of 2007 through May in 2009. The results were enumerated as follows. The results of tuberculin skin test are: 7 (0.4%) out of 1,697 in 2007, 61 (2.8%) out of 2,163 in 2008, 80 (4.9%) out of 1,639 in 2009. The sex and age distribution among the incidence of positive: 135 (91.8%) out of 147 in female, 12 (8.2%) in male. Among female, age 1: 6.1%, age 2: 30.6%, 3: 38.8%, 4: 14.2%, 5: 0.7% and 6: 1.4%. Among male, age 1: 4.1%, 2: 1.4%, 3: 2.7% and more frequent occurrence in age 3, 38.8% in female and 2.7% in male. The rate of recurrence by farms: recurrence 1: 6 (35.3%), 2: 9 (52.9%), 3: 1 (5.9%), 6: 1 (5.9%), The recurrence rate of 2 or more was 64.7%. The ELISA test result among 114 heads over 14 farms: 75 (65.8%) showed positive and 39 (34.2%) negative. Geographical distribution of recurrence is characterized as concentrated along the major traffic and stream crossing the village, and spread from the high elevation to downward area.

• Tuberculosis and Respiratory Diseases
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• v.72 no.5
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• pp.416-425
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• 2012

Background: The sensitivities and specificities of interferon-gamma release assays (IGRAs) vary among different population studies, and the data on the routine use of IGRAs are limited. The aim of this study was to evaluate the role of QuantiFERON-TB Gold In-Tube (QFT-GIT) test in the diagnosis of active tuberculosis. Methods: We conducted a prospective study, enrolling 77 patients with suspected pulmonary tuberculosis (TB), at a secondary care teaching hospital in Seoul. Results: In total, 12 (15.6%) patients showed indeterminate results due to positive control failure on the QFT-GIT test. Indeterminate results were significantly associated with the elderly, history of the intensive care unit stay, lymphocytopenia, especially low CD4 count, increased C-reactive protein and decreased protein levels. Of the 77 patients, 44 (57.1%) were diagnosed with active pulmonary tuberculosis, and the percentage of false negative results of the QFT-GIT was 36.4% (vs. 31.8% with TST). In the TB group with >65 years old (n=12), the proportions of the indeterminate (33.3% vs. 3.1%) and the false negative results (58.3% vs. 25.0%) of the QFT-GIT were significantly higher than in the younger TB group (n=32). Conclusion: Indeterminate and false negative results of QFT-GIT test were not infrequent in tuberculosis, especially in the elderly. Care should be considered for the interpretation with the elderly, immunocompromised, chronic and severely diseased patients.

• Pediatric Infection and Vaccine
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• v.23 no.2
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• pp.94-101
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• 2016

Purpose: This study aimed to describe the results of a contact investigation on health care workers after exposure to a house officer with smear-positive pulmonary tuberculosis (TB). Methods: Eighty nine out of 101 subjects who had close contact with the index patient agreed to be enrolled in the investigation. The first contact investigation was conducted approximately 30 days after the index patient's onset of symptoms, followed by the second investigation after 10 weeks. In both, clinical manifestations were studied, and chest X-ray and tuberculin skin test (TST)/QuantiFERON-TB Gold (QFT-G) in dual screening strategy were conducted. Results: The first TST resulted in positive in 34 subjects (38.2%). QFT-G was conducted on 16 subjects who tested positive in the first TST and aged under 36. Six of them (37.5%) were positive. The second TST was conducted on 41 subjects with negative results in the first TST. Seventeen (41.5%) were positive and among them, three (17.6%) showed positive QFT-G. None of the subjects were diagnosed with active TB. The probability of TB infection through contact with the index patient was 7.3% (3/41) in dual screening strategy while it was 41.5% (17/41) in TST strategy. Conclusions: This first hospital-setting contact investigation for tuberculosis in Korea revealed that latent tuberculosis infection (LTBI) rates vary depending on different diagnostic strategies. This indicates the need for systematic guidelines for diagnosing LTBI in health care workers who have professional exposure to TB.

• Tuberculosis and Respiratory Diseases
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• v.73 no.4
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• pp.219-223
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• 2012

Background: We investigated the prevalence of latent tuberculosis infection (LTBI) among medical students in South Korea. Methods: Students from one medical school, who were in second- or third-year classes before clerkship course, were enrolled for three consecutive years in the study. A standard questionnaire was given to each participant, and tuberculin skin test (TST), QuantiFERON-TB GOLD In-Tube (QFT-GIT) assay, and chest radiography were performed. Results: A total of 153 participants were enrolled in the study. The mean age of the subjects was $21.9{\pm}0.9$ years, 105 (68.6%) were male, and 132 (86.3%) had been vaccinated with Bacille Calmette-Gu$\acute{e}$rin (BCG). Four students (2.6%) had a history of contact with tuberculosis (TB) patients during medical practice. No abnormal chest radiograph findings were found for any of the subjects. Of the 153 subjects, 23 (15.0%) tested positive for the TST, and 8 (5.2%) tested positive for the QFT-GIT. The agreement between the two tests was determined to be 0.34 using kappa coefficients. Of the four students who had a history of contact with TB patients, only one subject tested positive for both tests, and the other three students tested negative for both tests. Conclusion: A low prevalence of LTBI was found among medical students before clerkship course in South Korea.

• Clinical and Experimental Pediatrics
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• v.59 no.6
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• pp.256-261
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• 2016

Purpose: Latent tuberculosis infection (LTBI) in young children may progress to severe active tuberculosis (TB) disease and serve as a reservoir for future transmission of TB disease. There are limited data on interferon-${\gamma}$ release assay (IGRA) performance in young children, which our research aims to address by investigating the usefulness of IGRA for the diagnosis of LTBI. Methods: We performed a tuberculin skin test (TST) and IGRA on children who were younger than 18 years and were admitted to Chung-Ang University Hospital during May 2011-June 2015. Blood samples for IGRA were collected, processed, and interpreted according to manufacturer protocol. Results: Among 149 children, 31 (20.8%) and 10 (6.7%) were diagnosed with LTBI and active pulmonary TB, respectively. In subjects lacking contact history with active TB patients, TST and IGRA results were positive in 41.4% (29 of 70) and 12.9% (9 of 70) subjects, respectively. The agreement (kappa) of TST and IGRA was 0.123. The control group, consisting of non-TB-infected subjects, showed no correlation between age and changes in interferon-${\gamma}$ concentration after nil antigen, TB-specific antigen, or mitogen stimulation in IGRAs (P=0.384, P=0.176, and P=0.077, respectively). In serial IGRAs, interferon-${\gamma}$ response to TB antigen increased in IGRA-positive LTBI subjects, but did not change considerably in initially IGRA-negative LTBI or control subjects. Conclusion: The lack of decrease in interferon-${\gamma}$ response in young children indicates that IGRA could be considered for this age group. Serial IGRA tests might accurately diagnose LTBI in children lacking contact history with active TB patients.

• Clinical and Experimental Pediatrics
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• v.51 no.9
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• pp.971-976
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• 2008

Purpose : Surveillance for detecting and managing latent tuberculosis infection (LTBI) is a key component of tuberculosis control. The classic surveillance tool, the tuberculin skin test (TST), may have some limitations when used in the Bacillus Calmette-$Gu{\acute{e}}rin$ (BCG)-vaccinated population. The object was to perform a blood test $QuantiFERON^{(R)}$-TB Gold In Tube (QFT-G IT) based on the detection of interferon-$\gamma$ ($IFN-{\gamma}$) released by T cells in response to Mycobacterium tuberculosis-specific antigens, and to compare the efficacy of this new diagnostic tool for LTBI with that of TST. Methods : For six months, between October 1, 2006 and April 30, 2007, data were collected from 111 patients under 15 years of age at Severance Children's Hospital. TST and QFT-G IT tests were performed with children with or without contact histories of tuberculosis. In addition to these tests, we examined comparative data from 29 adults who had tuberculosis, to detect false negative rates in the QFT-G IT method. Results : Thirty-three children had household contact histories. In this group, 15% and 42% of cases were found to be positive using the QFT-G IT assay and TST, respectively. Agreement was low between these two tests (${\kappa}=0.39$). In the adult active tuberculosis group, the QFT-G IT false negative rate defined as a positive culture and a negative QFT-G IT result was 12.5%. Conclusion : In diagnosing LTBI in children, the usefulness of a whole-blood $IFN-{\gamma}$ assay employing TB-specific antigens will be revealed only by examining additional longitudinal clinical data; this study serves as a starting point in that process.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7415-7419
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• 2013

The diagnosis of latent Mycobacterium tuberculosis infection (LTBI) is recommended in hematological malignancy patients and before hematopoietic stem cell transplantation (Guidelines for the prevention and management of infectious complications of solid organ transplantation, 2004). Compared to traditional methods such as tuberculin skin test (TST), T-SPOT.TB has been shown to be more specific. In the present study we enrolled 536 patients for whom T-SPOT.TB was performed, among which 295 patients also received the TST test. The agreement (79%) between T-SPOT.TB and TST was poor (x=0.274, P<0.001). The patients with positive T-SPOT.TB results numbered 62 (11.6%), in which only 20 (48.8%) of the 41 receiving the TST test had positive results. A majority of the patients with T-SPOT.TB positive results had some other evidence ofTB, such as TB history, clinical symptoms and an abnormal chest CT scan. Active TB was found in 9 patients, in which 2 had negative TST results. We followed up the patients and no one developed active TB. Our study suggested that the T-SPOT.TB may be more useful for screening LTBI and active TB in hematological malignancy patients and hematopoietic stem cell transplant recipients than the TST test.

• Tuberculosis and Respiratory Diseases
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• v.42 no.5
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• pp.669-676
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• 1995

Background: The cell-mediated immunity is needed for eradicating the tubercle bacilli. Prostaglandin(PG), especially PG $E_2$, is involved in cellular immunosuppression. It is known that the PG $E_2$ is suppressed by indomethacin. For using indomethacin as a immunomodulator of intractable pulmonary tuberculosis(Tbc) patients, we measured the tuberculin skin test(TST) and the plasma PG $E_2$ levels. Method: The forty-eight inpatients with sputum positive acid-fast stain bacilli were classified into 6 groups according to antiTbc chemotherapy history(new and intractable cases), plain chest roetgenogram(minimal and far advanced cases), and TST reaction(nagative and positive cases). Except for one group(n=2; new, minimal, and negative cases of TST reaction) of the 6 groups, all subjects(n=46) were measured for the plasma PG $E_2$, levels with radioimmunoassay. Results: 1) There was no significant difference in the plasma PG $E_2$ levels among A group(far advanced and positive TST reaction cases, n=10, $11.22{\pm}2.86\;pg/ml$), B group(minimal and negative TST reaction cases, n=9, $11.35{\pm}2.20$) and C group(far advanced and positive TST reaction cases, n=7, $11.11{\pm}2.30$) in the new cases(p>0.05). 2) There was no significant difference in the plasma PG $E_2$ levels between positive(n=10, $9.25{\pm}2.21$) and negative(n=10, $8.25{\pm}1.13$) groups by TST in the intractable cases(p>0.05). 3) Comparing the plasma PG $E_2$ levels between new(n=26, $11.35{\pm}2.41$) and intractable(n=20, $8.75{\pm}1.78$) groups, the intractable group had significi- andy lower plasma PG $E_2$ levels(p<0.05). 4) There was no significant difference in the plasma PG $E_2$ levels between negative(n=19, $9.88{\pm}2.43$) and positive(n=27, $10.46{\pm}2.56$) groups by TST(p>0.05). 5) There was no significant difference in the plasma PG $E_2$ levels between male(n=32, $10.07{\pm}2.44$) and female(n=14, $10.56{\pm}2.70$)(p>0.05). 6) There was no significant difference in the plasma PG $E_2$ levels among 2nd(n=5, $10.21{\pm}2.86$), 3rd(n=9, $9.97{\pm}2.47$), 4th(n=13, $11.35{\pm}2.33$) and 5th(n=19, $9.57{\pm}2.48$) decades(p>0.05). 7) There was no significant correlation between the induration sizes of the TST and the plasma PG $E_2$ levels(r=0.054, p>0.05). Conclusion: From the above results, the plasma PG $E_2$ levels of intractable group are not higher as the authors had expected. There was no significant difference in the plasma PG $E_2$ levels by the lesion sizes of plain chest roentgenogram and the induration sizes of TST, so more study will be needed to use the indomethacin as a immunomodulator for intractable pulmonary tuberculosis patients.

• Tuberculosis and Respiratory Diseases
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• v.59 no.4
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• pp.406-412
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• 2005

Background : Recently, two commercialized whole-blood assays, $QuantiFERON^{(R)}-TB$ Gold (QFT) and T $SPOT-TB^{(R)}$ (SPOT), which measure the $IFN-{\gamma}$ released in the whole blood after being incubation with mycobacterial antigens, were approved for the diagnosis of a latent tuberculosis infection (LTBI). However, there is data on whether or not the previously used PPD skin tests (TST) have any influence on the diagnostic ability of these ex-vivo $IFN-{\gamma}$ assays. Methods : Forty-six 15 year-old students who did not appear to be infected with Mycobacterium tuberculosis were enrolled in this study. The peripheral blood was collected and used for two $IFN-{\gamma}$ assays. The $IFN-{\gamma}$ assays and TST were performed at the baseline ($1^{st}$). The TST was repeated two months later ($2^{nd}$), and the $IFN-{\gamma}$ assays were repeated two ($2^{nd}$) and four months ($3^{rd}$) later only in those subjects who had negative results at the baseline in both the $IFN-{\gamma}$ assays and TST. An induration size > 10 mm was considered to be positive in the TST. Results : The mean TST value was $3.1{\pm}5.4mm$ (range: 0-20). Of the 46 subjects examined, 13 subjects (28.3%) showed positive results in the two-step TST. Nine (19.6%) were SPOT-positive and only one (2.2%) was QFT-positive. The $2^{nd}$ and $3^{rd}$ QFT were carried out in 23 and 25 all-negative subjects, respectively, and all showed negative results. The $2^{nd}$ SPOT was performed in 23 subjects and only one (4.3%) showed a weak-positive result. Conclusion : Even though there were some discrepancies in the results of the two ex-vivo $IFN-{\gamma}$ assays, it appears that their results were not influenced by a previous TST carried out in two or four months earlier.