PURPOSE: These days 5 TU purified protein derivative (PPD) is substituted with 2 TU PPD for the tuberculin skin test, a test essential in the diagnosis of tuberculosis in pediatric population. However, there had been no adequate criteria for the positivity of 2 TU PPD skin test. This study was performed to clarify the criteria of positive reactivity of 2 TU PPD skin test. The reactivity of 2 TU PPD was compared to that of 5 TU PPD. METHODS: One hundred and six medical students were tested with Mantoux method. Diameters of induration were measured 72 hours after the intradermal injections of 2 TU and 5 TU PPDs. Past history and family history of tuberculosis, history of BCG administration and the presence of BCG scar were recorded. RESULTS: One hundred and three subjects completed the study. Mean diameter of 2 TU tuberculin test was 10.3 mm and that of 5 TU test was 14.4mm, which was significantly different (P<0.001). The diameters were 0-24mm in the 2 TU test and 0-25mm in the 5 TU test. The diameter of induration in 2 TU test was positively correlated to that in 5 TU test (r2=0.63). Eighty-six subjects (83.5%) in the 2 TU test and 92 subjects (89.3%) in the 5 TU test had diameters of induration of 5mm or more; 59 (57.3%) subjects in the 2 TU test and 83 (80.6%) subjects in the 5 TU test had diameters of induration of 10 mm or more; 27 (26.2%) in the 2 TU test and 64 (62.1%) in the 5 TU test had diameters of induration of 15mm or more. Seventy-six of 103 subjects (73.7%) had greater diameters of induration in 5 TU test than in 2 TU, 22 (21.4%) had the same diameters, and 5 (4.9%) had greater diameters of induration in 2 TU test than in 5 TU test, and the last 5 subjects had indurations of more than 10mm diameter in both 2 TU and 5 TU tests. CONCLUSION: The criterion of positivity in 2 TU PPD skin test, essential for the diagnosis of tuberculosis, is different from that in 5 TU test. In this study, 6 mm or more was adequate for the criterion of positivity and 10mm or more for the criterion of strong positivity. Further studies should be done to establish a criterion for the pediatric population.
Cicatrix ; Diagnosis ; Humans ; Injections, Intradermal ; Mycobacterium bovis ; Skin Tests* ; Skin* ; Students, Medical ; Tuberculin ; Tuberculin Test ; Tuberculosis

OBJECTIVES: Health care workers(HCWs) are more likely to become infected with tuberculosis from patients in the hospital. When HCWs have an active tuberculosis infection, it is possible that they also become a source of infections to other HCWs and patients. METHODS: Tuberculin tests were performed with mantoux method using 5 units of tuberculin by infection control practitioners on Feb. 21, and Mar. 7, 1997. A total of 138 newly employed HCWs including 44interns and 94 nurses were tested. Results of skin test were interpreted by themselves according to the instructions. RESULTS: Among 138 personels, skin tests were negative in 27 personels (19.6%); 4 interns (9.1%) and 23 nurses (24.5%). There were 3 persons (2.2%) who had a history of tuberculosis which had been treated. CONCLUSION: The study showed that approximately 20% of newly employed HCWs had negative tuberculin skin test. Given the possibility of being infected with tuberculosis in the hospital, regular follow up of tuberculin skin test is warranted to protect HCWs,
Delivery of Health Care* ; Humans ; Infection Control Practitioners ; Skin Tests* ; Skin* ; Tuberculin Test ; Tuberculin* ; Tuberculosis

A small number of viable tuberculosis bacilli can reside in an individual with latent tuberculosis infection (LTBI) without obvious clinical symptoms or abnormal chest radiographs. Diagnosis and treatment for LTBI are important for tuberculosis (TB) control in public and private health, especially in high-risk populations. The updated 2014 Korean guidelines for TB recommend that tuberculin skin tests, interferon-gamma release assays, or a combination of the two can be used for LTBI diagnosis according to age and immune status of the host as well as TB contact history. The regimens for LTBI treatment include isoniazid, rifampicin, or isoniazid/rifampicin. However, results of drug susceptibility test from the index case must be considered in selecting the appropriate drug for recent contacts. Standardized LTBI diagnosis and treatment based on the new 2014 guidelines will contribute to the effective TB control in Korea as well as to the establishment of updated guidelines.
Diagnosis* ; Interferon-gamma Release Tests ; Isoniazid ; Korea ; Latent Tuberculosis* ; Radiography, Thoracic ; Rifampin ; Skin Tests ; Tuberculin ; Tuberculin Test ; Tuberculosis

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+/-0.9 years, 105 (68.6%) were male, and 132 (86.3%) had been vaccinated with Bacille Calmette-Guerin (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.
Humans ; Latent Tuberculosis ; Male ; Prevalence ; Surveys and Questionnaires ; Republic of Korea ; Schools, Medical ; Skin Tests ; Students, Medical ; Thorax ; Tuberculin ; Tuberculin Test ; Tuberculosis

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.
Bacillus ; Diagnosis ; Family Characteristics* ; Humans ; Interferon-gamma Release Tests ; Interferons* ; Latent Tuberculosis* ; Mycobacterium bovis ; Prevalence ; Skin Tests* ; Skin* ; Spouses ; Sputum ; Thorax ; Tuberculin Test ; Tuberculin* ; Vaccination

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.
Bacillus ; Diagnosis ; Family Characteristics* ; Humans ; Interferon-gamma Release Tests ; Interferons* ; Latent Tuberculosis* ; Mycobacterium bovis ; Prevalence ; Skin Tests* ; Skin* ; Spouses ; Sputum ; Thorax ; Tuberculin Test ; Tuberculin* ; Vaccination

BACKGROUND: There are several active tuberculosis (TB) cases in Korean high schools each school year. The risk of transmission in schools is extremely high due to the considerable time spent in closed classrooms. We evaluated the control of latent tuberculosis infection in Korean high schools. METHODS: When a student was identified with active TB, tuberculin skin testing was performed on their classmates and on students in their same school grade. When a student had a positive tuberculin skin tests (TST), they underwent follow-up testing with QuantiFERON-TB Gold In-Tube (QFT). The manufacturer recommended a cut-off of 0.35 IU/mL to determine QFT positivity was applied. RESULTS: A total of 131 pulmonary tuberculosis (TB) patients were included based on the criteria for screening TB contacts in the National Tuberculosis Control Program. Seventy-five (57.2%) students tested smear positive. TST were performed on 7,109 students who were classmates of, or in the same grade as, a TB patient. Of the contacts, 1,231 students (17.3%) were TST positive and they were screened with QFT. Six hundred-sixty-six (55.0%) of the tested students returned a positive QFT result and the rate of positivity was significantly associated with the increasing size of TST indurations (p<0.0001). CONCLUSION: The use of QFT resulted in approximately 45% of TST positive students not being given chemoprophylaxis.
Chemoprevention ; Follow-Up Studies ; Humans ; Interferon-gamma ; Interferon-gamma Release Tests ; Latent Tuberculosis ; Mass Screening ; Skin ; Skin Tests ; Tuberculin ; Tuberculin Test ; Tuberculosis ; Tuberculosis, Pulmonary

BACKGROUND: It remains uncertain if interferon-γ release assays (IGRAs) are superior to the tuberculin skin test (TST) for the diagnosis of active tuberculosis (TB) or latent tuberculosis infection (LTBI) in immunosuppressed populations including people with human immunodeficiency virus (HIV) infection. The purpose of this study was to systematically review the performance of IGRAs and the TST in people with HIV with active TB or LTBI in low and high prevalence TB countries. METHODS: We searched the MEDLINE database from 1966 through to January 2017 for studies that compared results of the TST with either the commercial QuantiFERON-TB Gold in Tube (QFTGT) assay or previous assay versions, the T-SPOT.TB assay or in-house IGRAs. Data were summarized by TB prevalence. Tests for concordance and differences in proportions were undertaken as appropriate. The variation in study methodology was appraised. RESULTS: Thirty-two studies including 4,856 HIV subjects met the search criteria. Fourteen studies compared the tests in subjects with LTBI in low TB prevalence settings. The QFTGT had a similar rate of reactivity to the TST, although the first-generation version of that assay was reactive more commonly. IGRAs were more frequently positive than the TST in HIV infected subjects with active TB. There was considerable study methodology and population heterogeneity, and generally low concordance between tests. Both the TST and IGRAs were affected by CD4 T-cell immunodeficiency. CONCLUSION: Our review of comparative data does not provide robust evidence to support the assertion that the IGRAs are superior to the TST when used in HIV infected subjects to diagnose either active TB or LTBI.
Diagnosis ; HIV Infections ; HIV ; Humans ; Interferon-gamma Release Tests ; Latent Tuberculosis ; Population Characteristics ; Prevalence ; Skin Tests ; Skin ; T-Lymphocytes ; Tuberculin Test ; Tuberculin ; Tuberculosis

Leprosy is an infectious dis as in which the immune machanism, in addition to the bacillus, plays an important role in Pathogenesis. As leprosy has two polar types, one of which is characterized by well preserved cellular immunity with a good prognosis and the other which shows no cellular immunity and a poor prognosis, it has been considercd the best human model for immunologic research. By studying the differences between these two typs, insights into immune deficiecies might well lead to the improved treatment of leproatous leproy(i.e.no cellular immunity) patients. Therefore, some immuno-theraputic trials for leprosy patients have already been reported by somc authors. In an attempt to survey spcific as well as nonspecific cellular immunity in leprosy, the authors prformed the lepromin and tuberculin skin tests with DNCB active cutanous sensitization on 203 leprosy patients in residence at the national leprosarium of Korea. All groups of Ieprosy patients showed decreased skin reactivity to the three tests, compared with normal, healthy control groups(p<0.01). This phenomenon is probably due to disorganization of lymphnode architecture and antigenic competition. Although a, statiscally significant difference could not be found in the tubercuIin and DNCB sensitization test results among all groups, the tuberculoid leprosy group and the arrested leprosy group showed stronger reactivity than the non-tuberculoid leprosy group. Patients positive for DNCB sensitization showed more positivity to the tuberculin test (66%)than to the lepromin test (30%) (p<0.01), thus suggesting that nonsp cific CMI and specific CMI exerted diffenent effects. Patients positive for DNCB sensitization also showed a greater probability (77%) to be responsive to either of the other two delayed cutanous hyperssensitivity tests than not. Leprosy patients in the third or fourth decade of life showed 63-66% positivity to DNCB active sensitization, while those in the six or seventh decad showed a positivity of 18-28%. These points toward significant correlation batween age and immun status. (p<0.01). The spontansous flare up during DNCB sensitization most frequently occurred on the 10th to 12th day of senitization: positive reaction after chalenge was most frequent in 72 hrs. after the test but some ractions were seen as late as five days after th. test. Two patiants of whole blood and its equivalent of leukocyte-rich plasme were irfused into 10 patients who had shown negative reaction to al! three tests. Conversion of delayed cutaneous hyprs:nsitivity among then was as follows; Four in tuberculin test (3 cases of which were strengthenings of preexisting ractivity). 2 in lepromin test, and 4 m DNCB sensitization. Of th 6 patients who showed a conversion in any one of the delayed cutaneous hypcrsensitivity evaluation tests, 4 showed conversion in more than two tests Of the 10 patients, who receivcd the transfusions (whole blood or lecocyte-rich plasma), 5 cases showed a high fever for 2 days afterrvards. The authors regard histocytotoxicity, incompatible histocompatibility, or perhaps simply a transfusion reaction as the underlying cause of this febrile reaction. One patient developed probably a phobia type psychosis following the blood transfusion and was subseuetly dropped from this study. Two months of observation following the transfusion revealed no definite clinical improvement.
Bacillus ; Blood Group Incompatibility ; Blood Transfusion ; Dinitrochlorobenzene ; Fever ; Histocompatibility ; Humans ; Immunity, Cellular* ; Korea ; Lepromin ; Leprosy* ; Leprosy, Tuberculoid ; Phobic Disorders ; Prognosis ; Psychotic Disorders ; Skin ; Skin Tests ; Tuberculin ; Tuberculin Test

Most authorities including WHO recommended immununizing infants with BCG as early as possible in areas prevalent with tuberculosis, however the optimal time for immunization has not well been characterized. Therefore the investigation was undertaken by vaccinating various infant groups of different ages with BCG and subsequently evaluating for adverse effects and tuberculin reactions, in order to contribute to undestanding the optimal time for immunization. Four hundred eighty three infants from the newborn nursery and the well baby clinic of Hanyang University Hospital who had no family history of tuberculosis were divided into three groups; group I of infants immunized within 7 days after birth, group II of infants immunized at about 1 month of age and group III of infants immunized at about 3 months of age. To each infant 0.1 ml of BCG(Institute Merieux, France) was administered intradermaly and approximately 3 months later tuberculin skin test using 5 TU PPD (NIH, Korea) was performed. Adverse reactions following BCG vaccination such as temperature elevation, induration alone or with suppuration at or near the injection site, and lymph node enlargement were also analyzed. The summary of the results is as follows. 1) Distribution of diameters of induration on tuberculin skin test illustrated incomplete bimodal configuration in all three different age groups. The means 2 standard deviations of diameters of indurations distributed on the main bells were 10.07 4.52 mm in group I, 10.65 3.82 mm in group II, and 10.83 5.08 mm in group III, and were not significantly different. 2) Criteria for positive tuberculin reaction was diameters of indurations equal to or greater than 6mm, 2 standard deviations below the mean values of diameters of indurations on the main bells. 3) The positive tuberculin reaction rates of 85.8% in group II and 88.6% in group III were significantly greater than 74.1% in group I. 4) Incidence of complications following BCG vaccination including temperature elevation, induration with suppuration, and localized lymphadenopathy was not different among three groups and the serious complications such as temperature elevation and lymphadenopathy were minimal. The data indicate that it is appropriate to immunize infants with BCG at about one month of age and the incidence of complications following BCG vaccination was not different among three infant groups of different ages.
Humans ; Immunization ; Incidence ; Infant* ; Infant, Newborn ; Lymph Nodes ; Lymphatic Diseases ; Mycobacterium bovis* ; Nurseries ; Parturition ; Skin Tests* ; Skin* ; Suppuration ; Tuberculin Test ; Tuberculin* ; Tuberculosis ; Vaccination*