• Neonatal Medicine
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• v.16 no.2
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• pp.182-189
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• 2009

Purpose: Recently, it is easy to find the causal virus of acute respiratory infections using multiplex RT-PCR. The aim of this study is to show the distribution of respiratory viruses and to define the characteristics of respiratory syncytial virus (RSV) infections compared to other respiratory viral infections. Methods: This was a prospective observational study conducted in the NICU. The infants with acute respiratory infections were performed multiplex RT-PCR using nasal swabs. The demographics, initial symptoms, course of illness, and laboratory and imaging findings were recorded. The infants were divided into RSV and No RSV groups. Results: Twenty-three infants (50%) were in the RSV group. Rhinovirus was the second most common virus. Coinfections with two viruses accounted for 6.5% of respiratory infections. The number of preterm infants, exposure to cigarette smoke and having siblings were not different between the two groups. Infections in the postnatal care center were more common in the RSV group than the No RSV group (60.9% vs. 21.7%, P=.007). Dyspnea (34.8% vs. 8.7%, P=.032) and pneumonia (73.9% vs. 43.5%, P=.036) were more common in the RSV group. The RSV group frequently needed oxygen (52.5% vs. 13.0%, P=.005) and received nothing by mouth (43.5% vs. 13.0%, P=.022). The incidence of right upper consolidation was higher in RSV group (56.5% vs. 8.7%, P=.001). Conclusion: This study showed that other viruses than RSV can induce respiratory infections in neonates and young infants born prematurely. RSV infections have a more severe course of illness than other respiratory viruses. We have to be careful of prevention even for healthy neonates especially in crowed situations, such as the postnatal care center.

• Tuberculosis and Respiratory Diseases
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• v.70 no.6
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• pp.490-497
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• 2011

Background: It is difficult but important to differentiate between bacterial and viral infections, especially for respiratory infections. Hence, there is an ongoing need for sensitive and specific markers of bacterial infections. We investigated novel biomarkers for discriminating community acquired bacterial pneumonia from 2009 H1N1 influenza A infections. Methods: This was a prospective, observational study of patients with community acquired bacterial pneumonia, 2009 H1N1 Influenza A infection, and healthy controls. Serum samples were obtained on the initial visit to the hospital and stored at $-80^{\circ}C$. We evaluated CRP (C-reactive protein), PCT (procalcitonin), LBP (lipopolysaccharide-binding protein) and copeptin. These analytes were all evaluated retrospectively except CRP. Receiver operating characteristic curve (ROC) analyses were performed on the resulting data. Results: Enrolled patients included 27 with community acquired bacterial pneumonia, 20 with 2009 H1N1 Influenza A infection, and 26 who were healthy controls. In an ROC analysis for discriminating community acquired bacterial pneumonia from 2009 H1N1 influenza A infection, areas under the curve (AUCs) were 0.799 for CRP (95% Confidence interval [CI], 0.664~0.934), 0.753 for PCT (95% CI, 0.613~0.892) and 0.684 for LBP (95% CI, 0.531~0.837). Copeptin was not different among the three groups. Conclusion: These findings suggest that serum CRP, PCT and LBP can assist physicians in discriminating community acquired bacterial pneumonia from 2009 H1N1 influenza A infection.

• Pediatric Infection and Vaccine
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• v.26 no.3
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• pp.199-205
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• 2019

Enteroviral infections are common in neonates. One important infection pathway is vertical transmission from an infected mother to her neonate. Here, we report the early detection and successful treatment of a vertically transmitted fulminant enteroviral infection associated with myocarditis and hepatitis. The patient had a sudden onset of high fever on the fourth day of life and developed severe, rapidly progressing symptoms of disseminated intravascular coagulopathy (DIC), hepatitis, and myocarditis accompanied by tachyarrhythmia. As it was the peak season for enteroviral infections and both the mother and the patient's 36-month-old sibling had a high fever around the time of delivery, we suspected an enteroviral infection. Thus, we initiated prompt evaluation of enteroviral infection, as well as close observation and intensive care of the neonate. We strongly recommend evaluation for the possibility of vertical enterovirus infection in neonates when the mother is suspected of having a viral infection (e.g., high fever and negative results from bacterial infectious studies) around the time of delivery and when the neonate shows some early symptoms of infectious diseases such as thrombocytopenia, DIC, hepatitis, and myocarditis. Early detection of enteroviral infections and prompt implementation of proper treatment are key to reduce the risk of complications and mortality associated with enteroviral infections in neonates.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2000.04a
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• pp.3-6
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• 2000

Antimicrobial resistance has been a well-recognized problem ever since the introduction of penicillin into clinical use. History of antimicrobial development can be categorized based on the major antibiotics that had been developed against emerging resistant $pathogens^1$. In the first period from 1940 to 1960, penicillin was a dominating antibiotic called as a "magic bullet", although S.aureus armed with penicillinase led antimicrobial era to the second period in 1960s and 1970s. The second stage was characterized by broad-spectrum penicillins and early generation cephalosporins. During this period, nosocomial infections due to gram-negative bacilli became more prevalent, while those caused by S.aureus declined. A variety of new antimicrobial agents with distinct mechanism of action including new generation cephalosporins, monobactams, carbapenems, ${\beta}$-lactamase inhibitors, and quinolones characterized the third period from 1980s to 1990s. However, extensive use of wide variety of antibiotics in the community and hospitals has fueled the crisis in emerging antimicrobial resistance. Newly appeared drug-resistant Streptococcus pneumoniae (DRSP), vancomycin-resistant enterococci (VRE), extended-spectrum ${\beta}$-lactamase-producing Klebsiella, and VRSA have posed a serious threat in many parts of the world. Given the recent epidemiology of antimicrobial resistance and its clinical impact, there is no greater challenge related to emerging infections than the emergence of antibiotic resistance. Problems of antimicrobial resistance can be amplified by the fact that resistant clones or genes can spread within or between the species as well as to geographically distant areas which leads to a global concern$^2$. Antimicrobial resistance is primarily generated and promoted by increased use of antimicrobial agents. Unfortunately, as many as 50 % of prescriptions for antibiotics are reported to be inappropriate$^3$. Injudicious use of antibiotics even for viral upper respiratory infections is a universal phenomenon in every part of the world. The use of large quantities of antibiotics in the animal health industry and farming is another major factor contributing to selection of antibiotic resistance. In addition to these background factors, the tremendous increase in the immunocompromised hosts, popular use of invasive medical interventions, and increase in travel and mixing of human populations are contributing to the resurgence and spread of antimicrobial resistance$^4$. Antimicrobial resistance has critical impact on modem medicine both in clinical and economic aspect. Patients with previously treatable infections may have fatal outcome due to therapeutic failure that is unusual event no more. The potential economic impact of antimicrobial resistance is actually uncountable. With the increase in the problems of resistant organisms in the 21st century, however, additional health care costs for this problem must be enormously increasing.

• Journal of Life Science
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• v.30 no.3
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• pp.221-229
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• 2020

Distylium racemosum is an evergreen tree growing wild on Jeju Island, which has been reported to exert biological activity. Obesity is induced by genetic, metabolic, environmental, and other factors. Among these, certain bacterial and viral infections have been shown to cause obesity, which is known as infectobesity. Human adenovirus (HAdV)-36 is one of the viruses that are known to cause infectobesity in humans. Unlike extensive research on preventing obesity and developing anti-obesity drugs, little research has been conducted specifically on the prevention and treatment of infectobesity. Therefore, this study aimed to evaluate the effects of phytochemicals from D. racemosum on the replication of HAdV-36. A549 cells infected with HAdV-36 were treated with an ethyl acetate fraction of a D. racemosum leaf extract (DRE), and the virus titer was calculated based on the hemagglutination (HA) titer. The results showed a concentration-dependent inhibitory effect of DRE treatment on HA titers. DRE treatment was also found to inhibit the cytopathic effects of the virus and the expression of viral genes. Quercitrin was identified as the constituent of DRE exerting an inhibitory effect on HAdV-36 replication. This study shows that DRE can be used as a candidate substance for the development of treatment for HAdV-36 infections. In addition, this study provides a basis to further investigate DRE for the development of anti-infectobesity medication.

• Pediatric Infection and Vaccine
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• v.17 no.1
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• pp.49-55
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• 2010

Purpose : The Purposes of this study are to identify the circulating etiologic viruses of acute lower respiratory tract infection in children and to understand the relation with clinical diagnosis. Methods : We obtained a total of 418 nasopharyngeal aspirates from children admitted for their acute lower respiratory tract infections at three tertiary hospitals in Seoul from September 2008 to March 2009. We performed multiplex RT-PCR to identify 14 etiologic viruses and analyzed their emerging patterns and clinical features. Results : Average age of patients was 16.4 months old and the ratio of male to female was 1.36. Viruses were detected in 56.2% of a total of 418 samples. Respiratory syncytial virus (35%) was the most frequently detected and followed by human rhinovirus (22%), human bocavirus, adenovirus, human metapneumovirus, parainfluenza virus, influenza virus and human coronavirus. Co-infection reached 21.9 % of positive patients. Conclusion : When we manage the patients with acute lower respiratory infectious diseases, we should remind the role of various viral pathogens, which might be circulating by seasons and by local areas.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.2
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• pp.109-123
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• 2020

Objectives: The aims of this study were to review the standards and key components of the standards for disposable masks in Korea, the US, EU, Japan, and China and to evaluate the appropriateness of disposable masks during a virus pandemic. Methods: We reviewed the standards in the above countries and compared their key elements for each standard. For the second purpose, systemic paper gathering using key words like 'mask', 'respirator' 'virus', and 'coronavirus' in the PubMed search engine was performed. Fifty-three papers were selected and reviewed in regard to the appropriateness of test protocols with sodium chloride(NaCl) particles for virus filtration and the effectiveness against viruses. Results: The standards for masks are largely divided into two categories: US standards and EU standards. In Korea, the Ministry of Employment and Labor adapted the EU standards for workers and the Health Masks adopted the Ministry of Employment and Labor standards by the Ministry of Food and Drug Safety. Regarding airborne viral infections, WHO emphasizes only droplet infection, while many studies have shown that small particles enter the air through coughing or sneezing, which increases the possibility of airborne infection. Compared to other particles, various factors such as airborne viability and the ability to replicate the virus in the body are further involved in the virus's airborne infection rate. Airborne infection is classified into absolute air infection, preferential air infection, and opportunistic air infection. The NaCl-certified N95 mask showed good filtration efficiency against viruses and NaCl particles were proved to be a surrogate material for viruses. From this, KF94 is also expected to be effective in blocking viruses. Conclusion: The N95 test method could be used as a surrogate test method for virus filtration. N95-class masks have been found to effectively block viral infections in the air. However, surgical or medical masks are only partially effective against airborne virus infection though they could effectively block large droplet infection. However, most studies considered in this study targeted N95 in foreign countries and studies on masks actually used in Korea are very limited, so studies on microorganisms and reuse on domestic masks should be conducted in the future.

• Journal of Veterinary Science
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• v.22 no.4
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• pp.43.1-43.10
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• 2021

Background: The H5 avian influenza viruses (AIVs) of clade 2.3.4.4 circulate in wild and domestic birds worldwide. In 2017, nine strains of H5N6 AIVs were isolated from aquatic poultry in Xinjiang, Northwest China. Objectives: This study aimed to analyze the origin, reassortment, and mutations of the AIV isolates. Methods: AIVs were isolated from oropharyngeal and cloacal swabs of poultry. Identification was accomplished by inoculating isolates into embryonated chicken eggs and performing hemagglutination tests and reverse transcription polymerase chain reaction (RT-PCR). The viral genomes were amplified with RT-PCR and then sequenced. The sequence alignment, phylogenetic, and molecular characteristic analyses were performed by using bioinformatic software. Results: Nine isolates originated from the same ancestor. The viral HA gene belonged to clade 2.3.4.4B, while the NA gene had a close phylogenetic relationship with the 2.3.4.4C H5N6 highly pathogenic avian influenza viruses (HPAIVs) isolated from shoveler ducks in Ningxia in 2015. The NP gene was grouped into an independent subcluster within the 2.3.4.4B H5N8 AIVs, and the remaining six genes all had close phylogenetic relationships with the 2.3.4.4B H5N8 HPAIVs isolated from the wild birds in China, Egypt, Uganda, Cameroon, and India in 2016-2017, Multiple basic amino acid residues associated with HPAIVs were located adjacent to the cleavage site of the HA protein. The nine isolates comprised reassortant 2.3.4.4B HPAIVs originating from 2.3.4.4B H5N8 and 2.3.4.4C H5N6 viruses in wild birds. Conclusions: These results suggest that the Northern Tianshan Mountain wetlands in Xinjiang may have a key role in AIVs disseminating from Central China to the Eurasian continent and East African.

• Obstetrics & gynecology science
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• v.61 no.6
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• pp.662-668
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• 2018

Objective This study was to identify the risk factors for cytological progression in women with atypical squamous cells of undetermined significance (ASC-US) or low-grade squamous intraepithelial lesions (LSIL). Methods We analyzed data from women infected with the human papillomavirus (HPV) who participated in the Korean HPV cohort study. The cohort recruited women aged 20-60 years with abnormal cervical cytology (ASC-US or LSIL) from April 2010. All women were followed-up at every 6-month intervals with cervical cytology and HPV DNA testing. Results Of the 1,158 women included, 654 (56.5%) and 504 (43.5%) women showed ASC-US and LSIL, respectively. At the time of enrollment, 143 women tested positive for HPV 16 (85 single and 58 multiple infections). Cervical cytology performed in the HPV 16-positive women showed progression in 27%, no change in 23%, and regression in 50% of the women at the six-month follow-up. The progression rate associated with HPV 16 infection was higher than that with infection caused by other HPV types (relative risk [RR], 1.75; 95% confidence interval [CI], 1.08-2.84; P=0.028). The cytological progression rate in women with persistent HPV 16 infection was higher than that in women with incidental or cleared infections (P<0.001). Logistic regression analysis showed a significant relationship between cigarette smoking and cytological progression (RR, 4.15; 95% CI, 1.01-17.00). Conclusion The cytological progression rate in HPV 16-positive women with ASC-US or LSIL is higher than that in women infected with other HPV types. Additionally, cigarette smoking may play a role in cytological progression.

• IMMUNE NETWORK
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• v.21 no.5
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• pp.33.1-33.19
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• 2021

IL-1β plays critical roles in the priming and effector phases of immune responses such as the differentiation, commitment, and memory formation of T cells. In this context, several reports have suggested that the IL-1β signal is crucial for CTL-mediated immune responses to viral infections and tumors. However, little is known regarding whether IL-1β acts directly on CD8⁺ T cells and what the molecular mechanisms underlying expression of IL-1 receptors (IL-1Rs) on CD8⁺ T cells and features of IL-1R⁺ CD8⁺ T cells are. Here, we provide evidence that the expression of IL-1R type I (IL-1RI), the functional receptor of IL-1β, is preferentially induced by IL-21 on TCR-stimulated CD8⁺ T cells. Further, IL-1β enhances the effector function of CD8⁺ T cells expressing IL-21-induced IL-1RI by increasing cytokine production and release of cytotoxic granules containing granzyme B. The IL-21-IL-1RI-IL-1β axis is involved in an augmented effector function through regulation of transcription factors BATF, Blimp-1, and IRF4. Moreover, this axis confers a unique effector function to CD8⁺ T cells compared to conventional type 1 cytotoxic T cells differentiated with IL-12. Chemical inhibitor and immunoprecipitation assay demonstrated that IL-21 induces a unique pattern of STAT activation with the formation of both STAT1:STAT3 and STAT3:STAT5 heterodimers, which are critical for the induction of IL-1RI on TCR-stimulated CD8⁺ T cells. Taken together, we propose that induction of a novel subset of IL-1RI-expressing CD8⁺ T cells by IL-21 may be beneficial to the protective immune response against viral infections and is therefore important to consider for vaccine design.