• Tuberculosis and Respiratory Diseases
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• 제70권1호
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• pp.28-35
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• 2011

Background: The aim of the study was to describe the characteristics, treatments, and outcomes of critically ill patients with pandemic Influenza A/H1N1 2009 at a major medical center in Korea. Methods: This retrospective observational study examined critically ill adult patients with pandemic Influenza A/H1N1 2009, who were admitted to the AMC between August and December 2009. Results: 27 patients with confirmed pandemic Influenza A/H1N1 2009 were admitted to the intensive care unit (ICU) at the Asan Medical Center (AMC). The median age (IQR) was 59 years (41~67), and 66.7% of the patients were older than 51 years. A total of 81.5% of the patients had 2 or more co-morbidities. The median time (IQR) from symptom onset to presentation was 2 days (1~4), and the median time from presentation to ICU admission was 0 days (0~1.5). All patients received oseltamivir (300 mg/day) and 13 patients received triple combination therapy (oseltamivir, amantadine, ribavirin). Twelve patients required mechanical ventilation on the first day of ICU admission. A total of 6 patients (22.2%) died within 28 days of admission. The patients who died had significantly higher acute physiology and chronic health evaluation (APACHE) II and sequential organ failure assessment (SOFA) scores at presentation. There were no significant differences in age, co-morbidities, or antiviral regimens between survivors and non-survivors. Conclusion: Critical illness related to pandemic Influenza A/H1N1 2009 was common in elderly patients with chronic co-morbidities. All patients were given high-dose oseltamivir or triple combination antiviral therapy. Nonetheless, patients with critical illnesses associated with pandemic Influenza A/H1N1 2009 had a death rate of 22.2%.

• Tuberculosis and Respiratory Diseases
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• 제69권1호
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• pp.24-30
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• 2010

Background: A novel 2009 influenza A (H1N1) virus emerged and disseminated to all over the world. There are few reports on the clinical characteristics of patients with complications. We describe the clinical features of pneumonia in adult patients hospitalized, who have novel influenza infection. Methods: There were 43 adult patients enrolled into the study with pneumonia of 528 hospitalized patients confirmed influenza A (H1N1) virus infection by real-time reverse transcriptase polymerase chain reaction testing, between 24 August 2009 and 31 January 2010. The clinical data of patients with pneumonia were collected retrospectively. Results: There were 22 of 43 (51.2%) influenza patients with pneumonia that had higher risk factors for complications. Compared to 28 patients with influenza A (H1N1) viral pneumonia and 15 patients, who had isolated bacteria from cultures, those with mixed viral and bacterial pneumonia were significantly more likely to have unilobar consolidations on chest radiographs (53.3 vs. 10.7%, p<0.01) and higher scores of pneumonia severity index (PSI; 90 [66~100] vs. 53 [28~90], p=0.04). Six patients required mechanical ventilation support in an Intensive Care Unit and were more likely to have dyspnea (83.3 vs. 29.3%, p=0.02) and low levels of $PaO_2$ (48.3 [37.0~70.5] vs 64.0 [60.0~74.5] mm Hg, p=0.02) and high levels of pneumonia severity index (PSI) score (108.0 [74.5~142.8] vs. 56.0 [40.5~91.0], p=0.03). Conclusion: The majority of pneumonia patients infected with novel influenza improved. Chest radiographic findings of unilobar consolidations suggest that mixed pneumonia is more likely. Initial dyspnea, hypoxemia, and high levels of PSI score are associated with undergoing mechanical ventilation support.

• Clinical and Experimental Pediatrics
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• 제55권12호
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• pp.474-480
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• 2012

Purpose: For evaluating the immunogenicity of an influenza vaccine, the microneutralization (MN) test has a higher sensitivity and specificity as compared to the hemagglutination inhibition (HI) test. However, the MN test is more time consuming and is difficult to standardize. We performed the MN test to determine its usefulness as an alternative or complementary test to the HI test for evaluating the immunogenicity of influenza vaccines. Methods: We compared the MN test with the HI test using 50 paired samples taken from a previous clinical study (2008-2009) in Korean children under 18 years of age. Results: The linear correlation coefficients of the 2 tests for H3N2, H1N1, and influenza B were 0.69, 0.70, and 0.66, respectively. We identified a high index of coincidence between the 2 tests. For an influenza vaccine, the postvaccination seroprotection rates and seroconversion rates determined by the MN test were 78.0% and 96.0%, 90% and 42.0%, and 42.0% and 48.0% for H3N2, H1N1, and influenza B, respectively. Geometric mean titer fold increases of H3N2, H1N1, and influenza B were 2.89, 5.04, and 4.29, respectively, and were 2.5-fold higher. We obtained good results in the evaluation of the immunogenicity of the 2008-2009 seasonal influenza vaccines. Conclusion: We found that the MN test was as effective as the HI test. Therefore, we suggest that the MN test can be used as an alternative or complementary test to the HI test for evaluating the immunogenicity of influenza vaccines.

• Tuberculosis and Respiratory Diseases
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• 제70권6호
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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.

• 한국가금학회지
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• 제40권3호
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• pp.243-252
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• 2013

Among the 16 hemagglutinin (HA) subtypes of avian influenza virus (AIV), only the H5 and H7 subtypes have caused highly pathogenic avian influenza (HPAI) in poultry. However, most H5 or H7 subtype viruses are categorized as low pathogenic avian influenza (LPAI). Some AIVs, including the H5 and H7 HPAI viruses, have shown the ability to infect humans directly. In this study, we describe the biological and molecular characterization of an H5N3 AIV (SBD/KR/KNU SYG06/06) isolated from spot-billed duck (Anas poecilorhyncha) in Korea. A phylogenetic analysis of the eight viral genes showed that the SBD/KR/KNU SYG06/06 isolate belongs to the Eurasian lineage and that the SBD/KR/KNU SYG06/06 isolate was clearly different from HPAI H5N1 strains, including human isolates and the Italian HPAI H5N2 strains. Additionally, no relationship was found between SBD/KR/KNU SYG06/06 and the Korean HPAI H5N1 isolates. The SBD/KR/ KNU SYG06/06 isolate had avian specific receptor binding site residues in the HA protein and the four C-terminal amino acids in the NS1 protein. The HA protein of the SBD/KR/KNU SYG06/06 isolate exhibited the typical LPAI motif at the cleavage site and this virus produced no cytopathic effects in MDCK cells without trypsin. Given these results, we suggest that the H5N3 AIV isolated from the spot-billed duck should be considered an LPAI virus and should have no pathogenic effect in humans.

• Clinical and Experimental Pediatrics
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• 제54권10호
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• pp.422-424
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• 2011

Acute disseminated encephalomyelitis (ADEM) is an inflammatory demyelinating disease of the central nervous system that typically follows an infection or vaccination and has a favorable long-term prognosis. We describe the first reported case of ADEM after vaccination against novel influenza A (H1N1). A previously healthy 34-month-old boy who developed ADEM presented with a seizure and left-sided weakness 5 days after vaccination against novel influenza A (H1N1). Cerebrospinal fluid examination revealed elevated cell counts. T2-weighted images and fluid-attenuated inversion recovery images revealed multiple patchy hyperintense lesions in the frontal and parietal subcortical white matter and the left thalamus. After the administration of intravenous corticosteroid, the patient's clinical symptoms improved and he recovered completely without neurologic sequelae.

• Clinical and Experimental Pediatrics
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• 제54권8호
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• pp.345-349
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• 2011

A 3-year-old girl with acute respiratory distress syndrome due to a H1N1 2009 influenza virus infection was complicated by necrotizing pneumonia was successfully treated with extracorporeal membrane oxygenation (ECMO). This is the first reported case in which a pediatric patient was rescued with ECMO during the H1N1 influenza epidemic in Korea in 2009.

• 한국간호교육학회지
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• 제17권2호
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• pp.277-286
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• 2011

Purpose: This study examined levels of stress and adherence to self care guidelines in elementary and middle school students who were infected with the influenza A (H1N1) virus in 2009. Method: A total of 649 students from J city participated in the survey. Stress was measured with the Impact of Event Scale-Revised which was developed by Weiss and Marmar (1997) and translated by Eun and colleagues (2005). Adherence to self care guidelines was measured with the scale developed by the authors based on the self care recommendations from Korea Centers for Disease Control and Prevention. Result: Levels of stress and adherence to self care guidelines were higher in elementary school students. However, the severity of participants' stress was less than moderate. The adherence level was significantly different depending on status of taking an antiviral agent, health education and self care education regarding the virus infection. Conclusion: Findings suggest that effects of health education under the national crisis situation due to influenza A (H1N1) virus pandemic were helpful. More in-depth study is needed to understand and to improve middle school students' self care behaviors.

• 한국가금학회지
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• 제46권3호
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• pp.173-183
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• 2019

조류인플루엔자 바이러스 H7 subtype에 속하는 바이러스 중 일부는 가금류에 감염할 경우 고병원성이 발휘된다. 또 H7 아형 AIV중 일부는 사람에 감염하여 사망 등을 유발할 수도 있다. 본 연구는 야생조류로부터 분리된 H7 아형 조류인플루엔자 바이러스 6주(H7N7 아형 4주, H7N1 아형 2주)를 대상으로 8개 유전자 분절 전체의 염기서열을 분석하여 병원성, 사람 감염 가능성 등 그 특성을 조사하였다. 계통유전학적 분석결과, 국내에서 분리된 H7 아형 분리주들은 8개 유전자(HA, NA, PB2, PB1, PA, NP, M, NS) 모두 Eurasian lineage로 분류되었으나, Eurasian lineage 내에서도 각기 다른 sublineage로 분류되어 유전적 다양성이 있는 것으로 분석되었다. 한국 분리주 6주는 HA 단백질 분절부위 아미노산은 두 종류(PEIPKGR 및 PELPKGR)의 motif를 가지고 있었으나, 모두 저병원성 바이러스 특성을 가지고 있었다. 숙주세포 결합 특이성과 관련 있는 HA 단백질 receptor-binding site를 분석한 결과, 한국 분리주 모두는 사람 세포 수용체 결합특이성보다는 조류 세포 수용체 결합 특이성을 가지는 것으로 나타났다. 사람 감염 가능성을 높게 하는 부위에서의 아미노산 치환(PB2 단백질의 E627K 및 PB1단백질의 I368V)도 나타나지 않았고, 또한 NA stalk region에서의 결손도 관찰되지 않았다. 이상의 결과를 미루어 볼 때 한국 야생조류에서 분리된 H7 아형 6주 모두는 저병원성 바이러스로 최근 중국에서 사람 감염이 나타나고 있는 H7N9 바이러스와는 유전적으로 다른 계열의 바이러스인 것으로 판단된다.

• Genomics & Informatics
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• 제14권3호
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• pp.96-103
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• 2016

The influenza A (H1N1) virus, also known as swine flu is a leading cause of morbidity and mortality since 2009. There is a need to explore novel anti-viral drugs for overcoming the epidemics. Traditionally, different plant extracts of garlic, ginger, kalmegh, ajwain, green tea, turmeric, menthe, tulsi, etc. have been used as hopeful source of prevention and treatment of human influenza. The H1N1 virus contains an important glycoprotein, known as neuraminidase (NA) that is mainly responsible for initiation of viral infection and is essential for the life cycle of H1N1. It is responsible for sialic acid cleavage from glycans of the infected cell. We employed amino acid sequence of H1N1 NA to predict the tertiary structure using Phyre2 server and validated using ProCheck, ProSA, ProQ, and ERRAT server. Further, the modelled structure was docked with thirteen natural compounds of plant origin using AutoDock4.2. Most of the natural compounds showed effective inhibitory activity against H1N1 NA in binding condition. This study also highlights interaction of these natural inhibitors with amino residues of NA protein. Furthermore, among 13 natural compounds, theaflavin, found in green tea, was observed to inhibit H1N1 NA proteins strongly supported by lowest docking energy. Hence, it may be of interest to consider theaflavin for further in vitro and in vivo evaluation.