• Tuberculosis and Respiratory Diseases
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• v.79 no.4
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• pp.201-206
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• 2016

Active tuberculosis (TB) has a greater burden of TB bacilli than latent TB and acts as an infection source for contacts. Latent tuberculosis infection (LTBI) is the state in which humans are infected with Mycobacterium tuberculosis without any clinical symptoms, radiological abnormality, or microbiological evidence. TB is transmissible by respiratory droplet nucleus of $1-5{\mu}m$ in diameter, containing 1-10 TB bacilli. TB transmission is affected by the strength of the infectious source, infectiousness of TB bacilli, immunoresistance of the host, environmental stresses, and biosocial factors. Infection controls to reduce TB transmission consist of managerial activities, administrative control, engineering control, environmental control, and personal protective equipment provision. However, diagnosis and treatment for LTBI as a national TB control program is an important strategy on the precondition that active TB is not missed. Therefore, more concrete evidences for LTBI management based on clinical and public perspectives are needed.

• Tuberculosis and Respiratory Diseases
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• v.83 no.2
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• pp.132-140
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• 2020

In human immunodeficiency virus (HIV)-infected patients, Pneumocystis jirovecii pneumonia (PCP) is a well-known opportunistic infection and its management has been established. However, PCP is an emerging threat to immunocompromised patients without HIV infection, such as those receiving novel immunosuppressive therapeutics for malignancy, organ transplantation, or connective tissue diseases. Clinical manifestations of PCP are quite different between patients with and without HIV infections. In patients without HIV infection, PCP rapidly progresses, is difficult to diagnose correctly, and causes severe respiratory failure with a poor prognosis. High-resolution computed tomography findings are different between PCP patients with HIV infection and those without. These differences in clinical and radiological features are due to severe or dysregulated inflammatory responses that are evoked by a relatively small number of Pneumocystis organisms in patients without HIV infection. In recent years, the usefulness of polymerase chain reaction and serum β-D-glucan assay for rapid and non-invasive diagnosis of PCP has been revealed. Although corticosteroid adjunctive to anti-Pneumocystis agents has been shown to be beneficial in some populations, the optimal dose and duration remain to be determined. Recent investigations revealed that Pneumocystis colonization is prevalent and that asymptomatic carriers are at risk for developing PCP and can serve as the reservoir for the spread of Pneumocystis by airborne transmission. These findings suggest the need for chemoprophylaxis in immunocompromised patients as well as infection control measures, although the indications remain controversial. Because a variety of novel immunosuppressive therapeutics have been emerging in medical practice, further innovations in the diagnosis and treatment of PCP are needed.

• Tuberculosis and Respiratory Diseases
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• v.79 no.4
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• pp.234-240
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• 2016

Transmission of tuberculosis (TB) is a recognized risk to patients and healthcare workers in healthcare settings. The literature review suggests that implementation of combination control measures reduces the risk of TB transmission. Guidelines suggest a three-level hierarchy of controls including administrative, environmental, and respiratory protection. Among environmental controls, installation of ventilation systems is a priority because ventilation reduces the number of infectious particles in the air. Natural ventilation is cost-effective but depends on climatic conditions. Supplemented intervention such as air-cleaning methods including high efficiency particulate air filtration and ultraviolet germicidal irradiation should be considered in areas where adequate ventilation is difficult to achieve. Personal protective equipment including particulate respirators provides additional benefit when administrative and environmental controls cannot assure protection.

• Tuberculosis and Respiratory Diseases
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• v.74 no.2
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• pp.63-69
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• 2013

Background: Aiming to improve outcome of lung transplantation (LTx) patients, we reviewed risk factors and treatment practices for the LTx recipients who experienced respiratory infection in the late post-LTx period (>1 month after LTx). Methods: We analyzed the clinical data of 48 recipients and donors from 61 LTx, who experienced late respiratory infections. Late respiratory infections were classified according to the etiology, time of occurrence, and frequency of donor-to-host transmission or colonization of the recipient prior to transplantation. Results: During the period of observation, 42 episodes of respiratory infections occurred. The organisms most frequently involved were gram (-) bacteria: Acinetobacter baumannii (n=13, 31.0%), Pseudomonas aeruginosa (n=7, 16.7%), and Klebsiella pneumoniae (n=4, 10.0%). Among the 42 episodes recorded, 14 occurred in the late post-LTx period. These were bacterial (n=6, 42.9%), fungal (n=2, 14.3%), viral (n=4, 28.5%), and mycobacterial (n=2, 14.3%) infections. Of 6 bacterial infections, 2 were from multidrug-resistant (MDR) A. baumannii and one from each of MDR P. aeruginosa, extended spectrum ${\beta}$-lactamase (+) K. pneumoniae, methicillin-resistant Staphylococcus aureus and Streptococcus pneumoniae. Infection-related death occurred in 6 of the 14 episodes (43%). Conclusion: Although the frequency of respiratory infection decreased sharply in the late post-LTx period, respiratory infection was still a major cause of mortality. Gram (-) MDR bacteria were the agents most commonly identified in these infections.

• Tuberculosis and Respiratory Diseases
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• v.80 no.1
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• pp.21-26
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• 2017

It is well established that health care workers (HCWs) have a considerably higher risk of occupationally acquired tuberculosis (TB). To reduce the transmission of TB to HCWs and patients, TB infection control programs should be implemented in health care settings. The first and most important level of all protection and control programs is administrative control. Its goals are to prevent HCWs, other staff, and patients from being exposed to TB, and to reduce the transmission of infection by ensuring rapid diagnosis and treatment of affected individuals. Administrative control measures recommended by the United States Centers for Disease Control and Prevention and the World Health Organization include prompt identification of people with TB symptoms, isolation of infectious patients, control of the spread of the pathogen, and minimization of time spent in health care facilities. Another key component of measures undertaken is the baseline and serial screening for latent TB infection in HCWs who are at risk of exposure to TB. Although the interferon-gamma release assay has some advantages over the tuberculin skin test, the former has serious limitations, mostly due to its high conversion rate.

• Journal of Digital Convergence
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• v.16 no.10
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• pp.389-398
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• 2018

This study aimed to investigate the knowledge, compliance and affecting factors of the cough etiquette to prevent the respiratory infectious disease transmission. Data were collected 250 self reporting questionnaires above 19 years old adult from Aug. 13th to Sep. 19th 2018. 213 questionnaires were analyzed statistically. In the results, the score was converted in terms of 100 points, knowledge of the cough etiquette was average $70.99{\pm}19.92$ points, compliance was $70.63{\pm}10.25$ points. Knowledge and compliance were statistically positive significant correlation, In the multiple regression analysis, the affecting factors were gender, usually carry a handkerchief, usually carry a portable tissue paper, average number of handwashes per day, know about cough etiquette, knowledge of cough etiquette. Therefore, it is necessary to develop and apply an educational program that reflects the affecting factors of cough etiquette in this study result. The higher level of cough etiquette performance will help prevent respiratory infection transmission.

• Journal of Korean Medical Science
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• v.33 no.53
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• pp.348.1-348.6
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• 2018

We report a case of Middle East respiratory syndrome coronavirus (MERS-CoV) infection in a 61-year-old businessman returning from Kuwait. The patient arrived there on August 16, 2018, developed watery diarrhea on August 28 (day 0), and came back to Korea on September 7 (day 10) as his condition worsened. Upon arrival, he complained of diarrhea and weakness, but denied any respiratory symptoms, and he directly went to visit an emergency room. Chest radiography revealed interstitial infiltrates in the lungs, and he was immediately transferred to an isolation unit. Quantitative real-time PCR analysis of sputum samples taken on day 11 returned positive for MERS-CoV. No secondary MERS-CoV infection was identified among people who had close contact with him. This case underscores the importance of a high index of suspicion of MERS-CoV infection in any febrile patients who present after a trip to the Middle East.

• Kidney Research and Clinical Practice
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• v.36 no.2
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• pp.111-116
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• 2017

The Korean Society of Nephrology participated in the task force team consisting of government authorities and civilian experts to prevent and control the spread of Middle East respiratory syndrome (MERS) in 2015. The Korean Society of Nephrology MERS Task Force Team took an immediate action and drafted 'the clinical recommendation for hemodialysis facilities' to follow when the first and the only confirmed case was reported in the hemodialysis unit. Owing to the dedicated support from medical doctors, dialysis nurses, and related medical companies, we could prevent further transmission of MERS infection successfully in hemodialysis units. This special report describes the experience of infection control during MERS outbreak in 2015 and summarizes the contents of 'the clinical practice guideline for hemodialysis facilities dealing with MERS patients' built upon our previous experience.

• Pediatric Infection and Vaccine
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• v.22 no.3
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• pp.131-135
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• 2015

Since April 2012, more than 1,600 laboratory-confirmed human infections with Middle East Respiratory Syndrome Coronavirus (MERS-CoV) have been reported, occurring primarily in countries in the Arabian Peninsula; the majority in Saudi Arabia. The MERS outbreak in Korea, which began in May 2015 through the importation of a single case who had recently traveled to Bahrain, the United Arab Emirates, Saudi Arabia, and Qatar. As of November 28th, 186 secondary and tertiary cases had been reported; 38 deaths, mainly associated with underlying chronic illnesses, were reported. One case was exported to China and has been recorded as the first MERS case in China. Thirty-seven confirmed cases were associated with the index case, who was hospitalized from May 15 to May 17. Emergency room at one of the nation's largest hospitals had been affected by hospital-to-hospital and intra-hospital transmissions of MERS-CoV, resulting in an outbreak of 90 infected patients. The vast majority of 186 confirmed cases are linked to a single transmission chain associated with health facilities. The median age of patients is 55 years, with a range of 16 to 87 years. The majority (61%) of patients are men. Twenty-five (14%) of the cases involve healthcare workers. The overall median incubation period was six days, but it was four days for secondary cases and six days for tertiary cases. There has been no evidence of airborne transmission and sustained human-to-human transmission in communities. Intensified public health measures, including contact tracing, quarantine and isolation of all contacts and suspected cases, and infection prevention and control have brought the MERS-CoV under control in Korea. Since 4 July no new cases have been reported.

• Acute and Critical Care
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• v.33 no.4
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• pp.238-245
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• 2018

Background: Infection by multidrug-resistant (MDR) pathogens leads to poor patient outcomes in intensive care units (ICUs). Contact precautions are necessary to reduce the transmission of MDR pathogens. However, the importance of the surrounding environment is not well known. We studied the effects of ICU relocation on MDR respiratory pathogen detection rates and patient outcomes. Methods: Patients admitted to the ICU before and after the relocation were retrospectively analyzed. Baseline patient characteristics, types of respiratory pathogens detected, antibiotics used, and patient outcomes were measured. Results: A total of 463 adult patients admitted to the ICU, 4 months before and after the relocation, were included. Of them, 234 were admitted to the ICU before the relocation and 229 afterward. Baseline characteristics, including age, sex, and underlying comorbidities, did not differ between the two groups. After the relocation, the incidence rate of MDR respiratory pathogen detection decreased from 90.0 to 68.8 cases per 1,000 patient-days, but that difference was statistically insignificant. The use of colistin was significantly reduced from 53.5 days (95% confidence interval [CI], 20.3 to 86.7 days) to 18.7 days (95% CI, 5.6 to 31.7 days). Furthermore, the duration of hospital stay was significantly reduced from a median of 29 days (interquartile range [IQR], 14 to 50 days) to 21 days (IQR, 11 to 39 days). Conclusions: Incidence rates of MDR respiratory pathogen detection were not significantly different before and after ICU relocation. However, ICU relocation could be helpful in reducing the use of antibiotics against MDR pathogens and improving patient outcomes.