• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.3
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• pp.289-297
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• 2019

Objectives: To identify the positive rate of and the risk factors associated with latent tuberculosis infection(LTBI) in mine workers, the objectives of the present study evaluated those among former mine workers. Methods: Between January 2015 and May 2017, former male mine workers who had been subjects for epidemiology research for work-related chronic obstructive pulmonary disease(COPD) and had received QuantiFERON-$TB^{(R)}$ Gold In-Tube(QFT-GIT) from the Institute of Occupation and Environment(IOE) under Korea Workers' Compensation and Welfare Service(KCOMWEL) were selected as the study subjects. To identify significant variables for increased risk of LTBI, logistic regression analysis was performed. Results: A total of 736 male former mine workers were selected as study subjects. The positive rate of LTBI among subjects was 69.2%(509/736). The current smoking[odds ratio(OR), 2.3; 95% confidence interval(CI), 1.1-4.9], COPD(OR, 1.4; 95% CI, 0.9-2.3), department loading(OR, 1.8; 95% CI, 0.9-3.4) and mining(OR, 1.5; 95% CI, 0.9-2.5), and working duration of over 20(OR, 1.6; 95% CI, 0.9-3.1) and over 30 years(OR, 2.2; 95% CI, 0.9-4.9) were associated with increased risk of LTBI. The interferon-gamma(IFN-${\gamma}$) level after stimulation with Mycobacterium tuberculosis(MTB)-specific antigens showed a significantly negative correlation with age(r=-0.126). Conclusions: The present study determined that the high positive rate of LTBI among mine workers was associated with not only the host factors but also the occupational exposure to mine dust.

• Biomedical Science Letters
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• v.24 no.2
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• pp.138-142
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• 2018

The incidence of tuberculosis (TB) in the Republic of Korea remains high when compared to the incidence in other Organization for Economic Cooperation and Development (OECD) countries. The prompt diagnosis and effective treatment of latent TB infection (LTBI) are very important in terms of controlling the burden of TB. The tuberculin skin test (TST) has long been the "gold standard" assay for the diagnosis of LTBI. However, it can show false positive results due to Bacille Calmette-$Gu{\acute{e}}rin$ (BCG) vaccination and infection with many environmental nontuberculous mycobacteria (NTM). The interferon gamma release assay (IGRA) using Mycobacterium tuberculosis (MTB)-specific antigens, was developed for the detection of LTBI. The QuantiFERON-TB Gold In-Tube assay is one of the most commonly used forms of the IGRA. In order to compare the diagnostic efficacy of the TST and IGRA in relation to LTBI among BCG-vaccinated healthy donors, whole blood samples were collected from 51 participants, and the results of the TST and IGRA were compared. Of the 51 cases, 18 cases (35.3%) were positive and 33 cases (64.7%) were negative when using the TST, while four cases (7.8%) were positive and 47 cases (92.2%) negative when using the IGRA. There was no correlation between the size of the induration in the TST and the $IFN-{\gamma}$ protein level. In conclusion, the TST showed higher cross-reactivity among the BCG-vaccinated healthy participants, therefore, the IGRA might be the most suitable assay for the rapid screening of LTBI in BCG-vaccinated healthy population, or for TB contact investigation.

• Tuberculosis and Respiratory Diseases
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• v.65 no.2
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• pp.79-90
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• 2008

국내에서 아직 잠복결핵 치료 대상 및 치료 방법에 대한 명확한 지침이 부족한 실정이며 이를 위해서는 잠복감염의 재활성화 혹은 새로운 감염이 어느 정도 결핵 발병의 원인이 되는지에 대한 연구가 선행되어야 한다. 그렇지만 발병의 위험이 높은 군을 선정하여 잠복결핵의 치료 대상으로 정하는 것이 타당할 것이며, 현재는 HIV 감염자, 전염성 결핵환자 가족 중 6세 미만의 아동, 중학생 및 고등학생에서의 집단 발병시 감염된 것으로 판정된 학생 및 종양괴사인자(tumor necrosis factor, TNF) 길항제 사용 예정인 잠복결핵 환자가 잠복결핵의 치료 대상으로 제한되어 있다. 향후에는 잠복결핵 치료 대상자의 확대가 필요할 것으로 생각되며, 치료방법 또한 isoniazid (INH) 단독 요법 이외에 rifampicin (RMP)을 포함하는 단기 요법의 사용도 고려하여야 하겠다. 현재 외국에서 잠복결핵의 치료법으로 권고되고 있는 것은 INH 6~9개월, RMP 4~6개월, INH/RMP 3개월 등이다. 과거부터 잠복결핵의 진단에 사용되어 온투베르쿨린 검사 외에 체외 인터페론감마 검사가 새로이 개발되면서 잠복결핵의 진단이 더 정확해진다면 이에 따라 잠복결핵 치료 방침도 수정될 가능성이 있으므로 새로운 검사법을 이용한 꾸준한 연구가 필요할 것이다.

• Tuberculosis and Respiratory Diseases
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• v.83 no.3
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• pp.201-210
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• 2020

Background: North Korea is one of the 30 countries with the highest tuberculosis (TB) and drug-resistant TB burdened. To understand the medical issues and research trends associated with TB in North Korea, we performed a comprehensive review of articles related to clinical and laboratory research on TB published in North Korean medical journals. Methods: We reviewed all types of TB-related articles published in nine North Korean medical journals (Yebang ŭihak: Preventive medicine; Koryo ŭihak: Korea Medicine; Chosŏn ŭihak: Chosun Medicine; Naekwa: Internal Medicine; Soa, sanbuinkwa: Pediatrics, Obstetrics, and Gynecology, Surgery; Ŭihak: Medicine; Kich'o ŭihak: Basic Medicine; and Chosŏn yakhak: Chosun Pharmacy). We classified the articles according to the type and field of study and analyzed the data qualitatively to gain insights. Results: We reviewed 106 articles (one- or two-page length) written in Korean, including reviews (n=43), original articles (n=52), and case reports (n=8). They were classified as follows: articles on diagnosis (n=52, 49%) and treatment (n=39, 37%). None of the studies investigated the commercialized molecular diagnosis systems such as Xpert MTB/RIF. Directly Observed Treatment, Short-course was reported as the basic treatment approach. Furthermore, six studies used Korean traditional medicines for treating TB, with one of them containing snake venom. Conclusion: The articles were not sufficiently detailed. Original articles on the treatment of multi-drug resistant TB were not found, and those on latent tuberculosis infection and nontuberculous mycobacteria were limited. To understand the current medical issues associated with TB in North Korea, articles from these nine journals were not sufficient.

• 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.57 no.2
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• pp.101-117
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• 2004

현증 결핵환자가 감소하고, 면역억제환자가 증가하고 있는 국내 추세에서 잠복결핵(latent tuberculosis)의 진단 및 치료 지침이 필요한 실정이다. 그러나 결핵의 유병률, 발생률 그리고 비씨지 접종률 등이 외국과 다른 국내의 현실에서 현증이 없는 잠복결핵의 진단 및 치료에 대한 방침은 필연적으로 외국과 다를 수 밖에 없으며, 현 시점에 국내에서 이에 대한 자료가 불충분하여 국내의 환경에 적합한 근거 중심의 지침을 설정하기는 어려운 상황이다. 그러나 결핵의 기본 병태 생리를 근거로 하여 최소한 결핵균 감염 이후 결핵 발병의 위험성이 높은 대상 환자에서는 잠복결핵 진단을 위한 검사를 시행하여 치료 여부를 결정하여야 한다. 고위험군은 사람면역결핍바이러스(human immunodeficiency virus, HIV) 감염자, 장기이식환자, 면역억제제를 장기간 사용하는 환자, 6세 이하의 소아 중 최근 전염성 결핵환자 접촉자 등을 우선적으로 고려해야 한다. 미국은 발병 위험도의 고, 중, 저에 따라 투베르쿨린 검사(tuberculin skin test, Mantoux test)의 양성기준을 달리 하여 잠복결핵을 진단하고 있으나, 국내에는 아직 이에 대한 자료가 부족하므로 발병의 위험이 높은 상기 고위험군을 대상으로 하여 PPD RT-23 2TU (Tuberculin unit)를 이용한 피부반응검사에서 10mm이상의 경결(induration)이 생성되는 경우를 양성으로 정하고 추후 연구 결과에 따라 재조정이 필요하다. 그 동안은 투베르쿨린 검사 결과 5-10 mm 사이의 경결반응을 보이는 면역억제 환자에 대하여는 개별적으로 의사의 판단에 따라 잠복결핵의 진단 및 치료 여부를 결정한다. 그러나 면역억제제를 사용하는 등 결핵 발병의 고위험군에서는 피부반응검사상 음성이라도 과거 결핵 치료력이 없이 흉부사진상 명백하게 과거에 결핵을 앓은 흉터가 남아있는 경우(석회화된 1차 결핵 소견은 제외)에는 잠복결핵의 치료를 시행한다. 상기 잠복결핵의 진단 및 검사의 적응증은 최소한 시행하여야 할 경우를 나열한 것으로 이외의 환자에 대하여는 환경 및 대상에 따라 개별화되어야 한다. 치료제로는 isoniazid (INH) 9개월 매일 치료(최소 한 6개월 이상, HIV양성 환자인 경우는 9개월), rifa-mpicin (RFP) 4개월 치료 및 INH/RFP 3개월 매일 치료를 시행할 수 있다. 상기 치료가 어려운 경우에는 RFP/pyrazinamide (PZA) 2개월 매일 치료를 고려할 수 있으나 중증 간독성의 가능성에 대한 철저한 교육 및 추적검사가 필요하다. 향후 국내 환경의 변화 및 연구결과에 따라 추후 부족한 부분에 대한 지침의 재정립이 필요하다.

• Journal of applied mathematics & informatics
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• v.29 no.3_4
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• pp.529-546
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• 2011

A deterministic tuberculosis model for theoretically assessing the potential impact of the combined effects of case detection in the presence of treatment is formulated. The qualitative features of its equilibria are analyzed and it is found that the disease-free equilibrium may not be globally asymptotically stable when the reproduction number is less than unity. This disease threshold number is further used to assess the impact of active TB case finding alone and in conjunction with treatment. A critical threshold parameter ${\Theta}$ say for which case detection will have a positive impact is derived. Using the Centre Manifold theory, the model may exhibit the phenomenon of backward bifurcation (coexistence of a locally stable endemic equilibrium with a stable disease-free equilibrium) when the reproduction number is less than unity. It is shown that the possibility of backward bifurcation occurring decreases with increase case detection. Graphical representations suggest that increase in case finding accompanied by treatment of detected TB cases, result in a marked decrease of TB cases (both latent and active TB).

• Journal of Korean Foot and Ankle Society
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• v.23 no.2
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• pp.71-73
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• 2019

Nearly one third of the world's population have active or latent tuberculosis, resulting in 1.5 million deaths annually. Tuberculosis involving the peripheral nerve is difficult to detect. Sural nerve tuberculoma is an extremely rare case of tuberculous involvement of the peripheral nerve that has attracted the attention of physicians. This paper reports a patient with sural nerve tuberculoma. A 58-year-old female patient presented with a palpable mass on the posterolateral calf with progressive tingling sensation on the distal area. The patient had no history of trauma and it was unclear whether the patient had any contact with individuals with active tuberculosis. The histopathologic findings revealed a granuloma-like lesion with caseous necrosis that was compatible with tuberculoma.

• Tuberculosis and Respiratory Diseases
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• v.73 no.4
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• pp.234-238
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• 2012

Recently, interferon gamma releasing assay has been recommended to compensate the tuberculin skin test (TST) for screening for latent tuberculosis infection (LTBI). Although it improved the detection of LTBI before treatment with tumor necrosis factor blocker, its application to immune suppressed patients is limited. We report a case of peritoneal tuberculosis (TB) developed in a patient who tested positive for TST and QuantiFERON-TB Gold (QFT-G) before infliximab therapy, to emphasize the importance of monitoring during treatment. A 52-year-old woman presented with abdominal distension. She had been diagnosed with seropositive rheumatoid arthritis six years ago. She had started taking infliximab six months ago. All screening tests for TB were performed and the results of all were negative. At admission, the results of repeated TST and QFT-G tests were positive. Histopathological examination confirmed peritoneal TB. The patient started anti-TB therapy and the symptoms were relieved.

• Tuberculosis and Respiratory Diseases
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• v.67 no.5
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• pp.454-457
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• 2009

Infliximab, a TNF-${\alpha}$ antagonist, has been used to treat refractory rheumatoid arthritis, ankylosing spondylitis, Crohn's disease and Behcet's disease. Tuberculosis (TB) is a well-known opportunistic infection in patients receiving infliximab. Therefore, patients should be screened and treated for latent or active TB infection before being administered infliximab. Recently, we encountered a case of military TB during infliximab therapy in a patient suffering from Behcet's disease and uveitis. We report this case with a review of the relevant literature.