• Tuberculosis and Respiratory Diseases
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• v.84 no.1
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• pp.1-12
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• 2021

Mycobacterium tuberculosis has infected more than two billion individuals worldwide, of whom 5%-10% have clinically active disease and 90%-95% remain in the latent stage with a reservoir of viable bacteria in the macrophages for extended periods of time. The tubercle bacilli at this stage are usually called dormant, non-viable, and/or non-culturable microorganisms. The patients with latent bacilli will not have clinical pictures and are not infectious. The infections in about 2%-23% of the patients with latent status become reactivated for various reasons such as cancer, human immunodeficiency virus infection, diabetes, and/or aging. Many studies have examined the mechanisms involved in the latent state of Mycobacterium and showed that latency modified the expression of many genes. Therefore, several mechanisms will change in this bacterium. Hence, this study aimed to briefly examine the genes involved in the latent state as well as the changes that are caused by Mycobacterium tuberculosis. The study also evaluated the relationship between the functions of these genes.

• Korean Journal of Veterinary Research
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• v.63 no.4
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• pp.41.1-41.6
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• 2023

Many viruses can infect different types of birds, with poultry being the most susceptible. These viral diseases have a direct negative impact on the poultry industry, with significant economic losses. This study examined a group of the most important viruses that infect backyard chickens in 2 specific areas of Basrah Governorate, south of Iraq. The study analyzed avian influenza viruses (AIVs), Newcastle disease virus (NDV), and infectious bronchitis virus (IBV). Two hundred and ninety oropharyngeal swabs, 150 from Abu Al-Khasib and 140 from Shatt Al-Arab regions in the Basrah governorate, were obtained from backyard chickens with clear respiratory signs. The samples were subjected to viral RNA extraction, and the viral nucleic acids were detected using a reverse transcriptase polymerase chain reaction technique. The overall rate of viral infections was 74.8%, which varied depending on the type of virus: 15.8%, 31.3%, and 27.5% for AIV, NDV, and IBV, respectively. The NDV and IBV had much higher infection rates than that of AIV. In addition, the prevalence of AIV in the Shatt Al Arab district was significantly higher than in the Abul Khasib district. Moreover, there were no significant differences between the NDV and the IBV distributions in either of the targeted regions in this study.

• Parasites, Hosts and Diseases
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• v.48 no.2
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• pp.113-120
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• 2010

To understand protozoan, viral, and bacterial infections in diarrheal patients, we analyzed positivity and mixedinfection status with 3 protozoans, 4 viruses, and 10 bacteria in hospitalized diarrheal patients during 2004-2006 in the Republic of Korea. A total of 76,652 stool samples were collected from 96 hospitals across the nation. The positivity for protozoa, viruses, and bacteria was 129, 1,759, and 1,797 per 10,000 persons, respectively. Especially, Cryptosporidium parvum was highly mixed-infected with rotavirus among pediatric diarrheal patients (29.5 per 100 C. parvum positive cases), and Entamoeba histolytica was mixed-infected with Clostridium perfringens (10.3 per 100 E. histolytica positive cases) in protozoan-diarrheal patients. Those infected with rotavirus and C. perfringens constituted relatively high proportions among mixed infection cases from January to April. The positivity for rotavirus among viral infection for those aged $\leq$ 5 years was significantly higher, while C. perfringens among bacterial infection was higher for $\geq$ 50 years. The information for association of viral and bacterial infections with enteropathogenic protozoa in diarrheal patients may contribute to improvement of care for diarrhea as well as development of control strategies for diarrheal diseases in Korea.

• Pediatric Infection and Vaccine
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• v.14 no.2
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• pp.136-144
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• 2007

Purpose : Human bocavirus (HBoV) was recently identified world widely in clinical specimens from infants and children with respiratory tract illness, but the role of HBoV in respiratory tract illnesses is unknown. The aim of this study was to investigate the frequency and the clinical manifestation of HBoV in pediatric patients. Methods : We retrospectively investigated 1,777 throat swab obtained between 2005 and 2006 from pediatric in-patients with acute respiratory tract diseases at the Kwang-ju Christian Hospital. The medical records of patients with positive results were reviewed for demographic and clinical data of HBoV infections. Results : HBoV DNA was found in 84 (4.7%) of the 1,777 hospitalized children and the mean age was 19 months. The most common diagnosis were pneumonia (67.8%), bronchiolitis (35.7%). HBoV infections were found year-round, though most occurred in spring and winter months. Conclusion : HBoV is frequently found in hospitalized infants and children with acute respiratory tract diseases in Korea, but an association of HBoV with a distinct respiratory tract manifestation was not apparent. To clarify the clinical significance of HBoV, further evaluation of various age groups and clinical groups is needed.

• Pediatric Infection and Vaccine
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• v.23 no.2
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• pp.109-116
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• 2016

Purpose: Recent observational studies have found that vitamin D deficiency is associated with respiratory tract infections. However, randomized controlled trials (RCTs) regarding the efficacy of vitamin D in childhood respiratory tract infection (RTI) have yield inconsistent results. We performed a systematic review and meta-analysis to evaluate the association between vitamin D supplementation and the risk of RTI. Methods: A comprehensive search was conducted using MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trial. Randomized controlled trials of vitamin D supplementation for prevention of RTI in children were included for the analysis. Cochrane Collaboration's tool for assessing the risk of bias was used to assess the quality of the studies. Pooled risk ratios with 95% confidence intervals (CIs) were meta-analyzed using Review Manager 5.3. Results: A total of seven RCTs were included in the meta-analysis. According to a random-effects model, the risk ratio for vitamin D supplementation was 0.82 (95% CI: 0.69-0.98) and $I^2=62%$ for heterogeneity. On subgroup analysis, heterogeneity decreased in the subgroup with follow-up less than 1 year, participants ${\geq}5years$ of age, patients subgroup, and subgroup with dosing daily. Funnel plot showed that there might be publication bias in the field. Conclusions: The present meta-analysis supports a beneficial effect of vitamin D supplementation for the prevention of RTI in children. However, the result should be interpreted with caution due to limitations including a small number of available RCTs, heterogeneity among the studies, and potential publication bias.

• Journal of Life Science
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• v.24 no.10
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• pp.1118-1124
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• 2014

Porcine respiratory disease complex (PRDC) is a common respiratory disease in nursery and grow-finishing pigs. A complex of viral and bacterial agents is known to be involved in the etiology of PRDC. The purpose of this study was to investigate common etiologic agents associated with PRDC in the field and compare detection methods for identifying these agents. To understand the mechanism of polymicrobial infection in PRDC, changes in the expression of cytokines were investigated. In 461 pig samples examined, most of the affected pigs ranged from 3 to 10 weeks old (73.4%), and 348 (75.4%) samples were confirmed as polymicrobial infection. Of the polymicrobial-infected cases, two (50.3%), three (32.2%), four (13.8%), five (3.2%), and six (0.5%) agents were detected. Two- or three-agent infections were the most common, with PRRSV/PCV-2 (44.6%) the most common two-agent infection. PRRSV/PCV-2/H. parasuis (11.0%) was the most common three-agent infection. Comparison of two detection methods (PCR and IHC) in the polymicrobial cases showed that 78.4% were PCV-2 positive with the PCR method, and 26.2% were PCV-2 positive with IHC. SIV was 7.8% by the PCR method and 3.7% positive by the IHC. This result indicates that the PCR method is more useful than IHC for detecting causative agents in PRDC. In the analysis of cytokines in the two- and three-agent infected samples, interleukin (IL)-$1{\alpha}$, IL-2, IL-4, IL-6, IL-10, and INF-${\alpha}$ showed the same expression pattern. All cytokines were suppressed, except IL-6. These findings indicate that changes in cytokine expression could be used to understand the mechanism of polymicrobial infection in PRDC.

• Pediatric Infection and Vaccine
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• v.22 no.3
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• pp.136-142
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• 2015

The Korean Society of Pediatric Infectious Diseases (KSPID) has participated in the task force team consisting of government authorities as well as civil medical experts and facilities to block the spread of Middle East Respiratory Syndrome in 2015. KSPID posted the "Middle East Respiratory Syndrome (MERS) Pop-up" in the homepage of The Korean Pediatric Society and The Korean Society of Pediatric Infectious Diseases. KSPID also released the "Guidelines for testing for MERS in children and adolescents" and the "Instructions for the Operation of National Safe Hospital" for children and adolescents in a timely manner. Such actions were aimed to prevent unnecessary anxieties, studies and isolation of pediatric patients with respiratory symptoms and signs caused by other common microbial etiologies as being suspected for MERS patients. This strategy relieved the doctors and parents from unnecessary fear and prevented the loss of unnecessary health care costs, and has proven to be a well-judged guideline and management protocol as evaluated after the final end of MERS outbreak. KSPID and its members should support the presence of pediatric infectious disease (PID) specialists in every medium size hospitals in Korea by developing the need for consultation fees for PID consultation in the hospital based practice and promoting the potential for cost savings related to prevention of health care associated infections and optimal prescription of antimicrobial agents. KSPID and its members need to approach and develop a communication plan to political decision makers to demonstrate and convince them of the importance of a PID specialist service.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.30 no.2
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• pp.107-111
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• 2019

Background and Objectives Idiopathic unilateral vocal fold paralysis (IVFP) is believed to be due to inflammation and edema of the recurrent laryngeal nerve caused by viral diseases such as upper respiratory tract infections. Corticosteroid has a potent anti-inflammatory action which should minimize nerve damage. The purpose of this study was to investigate the effect of oral steroid therapy on IVFP. Materials and Method Study was performed for the IVFP patient from January 2012 to August 2017. Patient's dermography, direction and location of paralyzed vocal cords, history of hypertension, diabetes, cerebrovascular disease, and other underlying disease, smoking history, alcohol consumption and upper respiratory tract infection, and symptoms were investigated. Treatment was divided into three groups: the observation group, low-dose group, and high-dose group, and the recovery rate and time of vocal cord paralysis were analyzed in each group. Results Thirty-seven patients were enrolled in this study. There was no relationship between oral steroid use, dosage and recovery of vocal cord paralysis. Oral steroids showed a rapid recovery of vocal cord paralysis, but there was no statistically significant difference in the time of recovery of vocal palsy with or without steroids (p=0.673). In addition, there was no statistically significant difference in recovery rate between the period to start of treatment, presence of diabetes mellitus, and treatment modality, but the recovery rate was high in the group with upper respiratory tract infection history (p=0.041). Conclusion In IVFP, oral steroid therapy has no significant difference in time and extent of recovery compared to the case of spontaneous recovery.

• Journal of Microbiology and Biotechnology
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• v.26 no.4
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• pp.684-692
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• 2016

Acute respiratory virus infectious diseases are a growing health problem, particularly among children and the elderly. Much effort has been made to develop probiotics that prevent influenza virus infections by enhancing innate immunity in the respiratory tract until vaccines are available. Lactobacillus plantarum GB-LP2, isolated from a traditional Korean fermented vegetable, has exhibited preventive effects on influenza virus infection in mice. To identify the molecular basis of this strain, we conducted a whole-genome assembly study. The single circular DNA chromosome of 3,284,304 bp was completely assembled and 3,250 protein-encoding genes were predicted. Evolutionarily accelerated genes related to the phenotypic trait of anti-infective activities for influenza virus were identified. These genes encode three integral membrane proteins, a teichoic acid export ATP-binding protein and a glucosamine - fructose-6-phosphate aminotransferase involved in host innate immunity, the nonspecific DNA-binding protein Dps, which protects bacteria from oxidative damage, and the response regulator of the three-component quorum-sensing regulatory system, which is related to the capacity of adhesion to the surface of the respiratory tract and competition with pathogens. This is the first study to identify the genetic backgrounds of the antiviral activity in L. plantarum strains. These findings provide insight into the anti-infective activities of L. plantarum and the development of preventive probiotics.

• Research in Community and Public Health Nursing
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• v.30 no.4
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• pp.460-470
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• 2019

Purpose: This study was to identify the factors influencing the practice of respiratory infection prevention (RIP) for the elderly residing in rural areas. Methods: The data were collected from 188 residents aged 65 years or older residing in the jurisdictions of four public health clinics in rural areas of C city, using a structured questionnaire for the period from December 1, 2018 to February 28, 2019. The collected data were analyzed with independent t-test, one-way ANOVA, Pearson's correlation coefficients, and hierarchical multiple regression analysis using SPSS/WIN 25.0 program. Results: The score on knowledge of RIP was 8.82±1.36, while it was 4.53±0.47 for attitude, 3.78±0.66 for practice, and 3.78±0.69 for social capital. It was observed that the factors influencing the practice of RIP were attitude of RIP (β=.38, p<.001), social capital (β=.29, p<.001), family type (β=-.19, p=.002), and subjective health status (β=.15, p=.035), while the explanatory power of the model was 47%. Conclusion: Consequently, to enhance the practice of RIP for the elderly residing in rural areas, it is necessary to develop programs considering social and environmental characteristics of rural areas based on their attitude of RIP, social capital, family type and subjective health status.