• Tuberculosis and Respiratory Diseases
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• v.79 no.2
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• pp.70-73
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• 2016

In late March of 2009, an outbreak of influenza in Mexico, was eventually identified as H1N1 influenza A. In June 2009, the World Health Organization raised a pandemic alert to the highest level. More than 214 countries have reported confirmed cases of pandemic H1N1 influenza A. In Korea, the first case of pandemic influenza A/H1N1 infection was reported on May 2, 2009. Between May 2009 and August 2010, 750,000 cases of pandemic influenza A/H1N1 were confirmed by laboratory test. The H1N1-related death toll was estimated to reach 252 individuals. Almost one billion cases of influenza occurs globally every year, resulting in 300,000 to 500,000 deaths. Influenza vaccination induces virus-neutralizing antibodies, mainly against hemagglutinin, which provide protection from invading virus. New quadrivalent inactivated influenza vaccine generates similar immune responses against the three influenza strains contained in two types of trivalent vaccines and superior responses against the additional B strain.

• Journal of Preventive Medicine and Public Health
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• v.52 no.5
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• pp.308-315
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• 2019

Objectives: Estimating influenza-associated mortality is important since seasonal influenza affects persons of all ages, causing severe illness or death. This study aimed to estimate influenza-associated mortality, considering both periodic changes and age-specific mortality by influenza subtypes. Methods: Using the Microdata Integrated Service from Statistics Korea, we collected weekly mortality data including cause of death. Laboratory surveillance data of respiratory viruses from 2009 to 2016 were obtained from the Korea Centers for Disease Control and Prevention. After adjusting for the annual age-specific population size, we used a negative binomial regression model by age group and influenza subtype. Results: Overall, 1 859 890 deaths were observed and the average rate of influenza virus positivity was 14.7% (standard deviation [SD], 5.8), with the following subtype distribution: A(H1N1), 5.0% (SD, 5.8); A(H3N2), 4.4% (SD, 3.4); and B, 5.3% (SD, 3.7). As a result, among individuals under 65 years old, 6774 (0.51%) all-cause deaths, 2521 (3.05%) respiratory or circulatory deaths, and 1048 (18.23%) influenza or pneumonia deaths were estimated. Among those 65 years of age or older, 30 414 (2.27%) all-cause deaths, 16 411 (3.42%) respiratory or circulatory deaths, and 4906 (6.87%) influenza or pneumonia deaths were estimated. Influenza A(H3N2) virus was the major contributor to influenza-associated all-cause and respiratory or circulatory deaths in both age groups. However, influenza A(H1N1) virus-associated influenza or pneumonia deaths were more common in those under 65 years old. Conclusions: Influenza-associated mortality was substantial during this period, especially in the elderly. By subtype, influenza A(H3N2) virus made the largest contribution to influenza-associated mortality.

• Osong Public Health and Research Perspectives
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• v.9 no.6
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• pp.348-353
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• 2018

Objectives: This study was conducted to determine whether essential oils had anti-influenza A/WS/33 virus activity and whether there were specific compounds associated with this activity. Methods: There were 63 essential oils evaluated for anti-influenza (A/WS/33 virus) activity using a cytopathic effect reduction method. The chemical composition of the anti-influenza essential oils was phytochemically analyzed by gas chromatography-mass spectrometry. Results: The antiviral assays demonstrated that 11 of the 62 essential oils ($100{\mu}g/mL$) possessed anti-influenza activity, reducing visible cytopathic effects of influenza A/WS/33 virus activity by > 30%. Furthermore, marjoram, clary sage and anise oils exhibited anti-influenza A/WS/33 virus activity of > 52.8%. However, oseltamivir (the anti-influenza A and B drug), showed cytotoxicity at the same concentration ($100{\mu}g/mL$) as the essential oils. The chemical composition detected by GC-MS analysis, differed amongst the 3 most potent anti-viral essential oils (marjoram, clary sage and anise oils) except for linalool, which was detected in all 3 essential oils. Conclusion: This study demonstrated anti-influenza activity in 11 essential oils tested, with marjoram, clary sage and anise essential oils being the most effective at reducing visible cytopathic effects of the A/WS/33 virus. All 3 oils contained linalool, suggesting that this may have anti-influenza activity. Further investigation is needed to characterize the antiviral activity of linalool against influenza A/WS/33 virus.

• Korean Journal of Adult Nursing
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• v.21 no.6
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• pp.593-602
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• 2009

Purpose: This study was to provide baseline data about nurses' Influenza A (H1N1) knowledge, awareness, and practice of infection control and to identify the significant factor affecting the level of practice. Methods: The subjects of this study were 144 nurses who worked at Influenza A (H1N1) regional base Hospital in D city. Data were collected by self-reported questionnaires during September 2009. The collected data were analyzed using SPSS/WIN 12.0 program. Results: The knowledge of Influenza A (H1N1) was statistically different according to age, unit, career and experience of seasonal influenza vaccination during the last year. The awareness of infection control was statistically different according to age, career, experience of seasonal influenza vaccination for last year and intention to get seasonal influenza vaccination for this year. The practice of infection control was statistically different according to unit, experience of seasonal influenza vaccination for last year, intention to get seasonal influenza vaccination for this year and intention to get Influenza A (H1N1) vaccination for this year. There was positive correlation among knowledge, awareness and practice (p < .05). Awareness was the significant factor affecting the level of practice. Conclusion: An educational program focusing on strategy to change nurse's awareness can be effective for infection control of Influenza A (H1N1) in regional base hospitals.

• Korean Journal of Clinical Laboratory Science
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• v.42 no.1
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• pp.1-15
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• 2010

Swine influenza virus (SIV) or swine-origin influenza virus (S-OIV) is endemic in swine, and classified into influenza A and influenza C but not influenza B. Swine influenza A includes H1N1, H1N2, H3N1, H3N2 and H2N3 subtypes. Infection of SIV occurs in only swine and that of S-OIV is rare in human. What human can be infected with S-OIV is called as zoonotic swine flu. Pandemic 2009 swine influenza H1N1 virus (2009 H1N1) was emerged in Mexico, America and Canada and spread worldwide. The triple-reassortant H1N1 resulting from antigenic drift was contained with HA, NA and PB1 of human or swine influenza virus, PB2 and PA polymerase of avian influenza virus, and M, NP and NS of swine influenza virus, The 2009 H1N1 enables to transmit to human and swine. The symptoms and signs in human infected with 2009 H1N1 virus are fever, cough and sore throat, pneumonia as well as diarrhea and vomiting. Co-infection with other viruses and bacteria such as Streptococcus pneumoniae can occur high mortality in high-risk population. 2009 H1N1 virus was easily differentiated from seasonal flu by real time RT-PCR which contributed rapid and confirmed diagnosis. The 2009 H1N1 virus was treated with NA inhibitors such as oseltamivir (Tamiflu) and zanamivir (Relenza) but not with adamantanes such as amantadine and rimantadine. Evolution of influenza virus has continued in various hosts. Development of a more effective vaccine against influenza prototypes is needed to protect new influenza infection such as H5 and H7 subtypes to infect to multi-organ and cause high pathogenicity.

• Pediatric Infection and Vaccine
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• v.20 no.2
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• pp.89-97
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• 2013

Purpose: This retrospective study was performed to identify the clinical characteristics of influenza B infection and compare to influenza A infection. Methods: Medical records of patients diagnosed with influenza using a multiplex PCR test, admitted to Seoul St. Mary's Hospital, during the 2011-2012 influenza season were analyzed. Clinical and laboratory characteristics of influenza B patients were investigated and compared with those of influenza A patients. Results: A total of 145 influenza patients were enrolled during this study period. Among these, 66 and 78 patients were diagnosed with influenza A and B, respectively, and 1 patient was diagnosed with co-existing influenza A and B. Cough (88.2%), rhinorrhea (77.1%) and sputum (60.4%) were the most common symptoms among these influenza patients, and most were diagnosed with upper respiratory infection (31.9%) or lower respiratory infection (49.3%). In comparison to influenza A patients, influenza B patients were older ($4.7{\pm}4.1$ years vs. $3.3{\pm}2.5$ years, P=0.016), and the number of fever days before hospitalization were longer (3.0 days vs. 2.5 days, P=0.043). While sore throat (10.3% vs. 1.5%, P=0.039) and vomiting (20.5% vs. 6.1%, P=0.012) were more common in influenza B patients than in influenza A patients, other clinical and laboratory characteristics were not significantly different between the two groups. Conclusions: No significant differences in clinical and laboratory perspectives were manifested in influenza A and B infections. Preventive measures should be emphasized over treatment in influenza B due to prolonged fever duration before admission.

• Journal of Korean Biological Nursing Science
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• v.18 no.2
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• pp.110-117
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• 2016

Purpose: This study was conducted to compare the incidence rate of influenza-like illnesses between an influenza-vaccinated group and a non-vaccinated group of adults. Methods: From July 1, 2015 to July 30, 2015, self-reporting questionnaires were given to 300 adults living in the Seoul and Gyeonggi-do, Korea. 265 survey questionnaires that had an earnest response were used for data analysis. The collected data were analyzed using the statistical software SPSS Win 18.0 version. Results: 52.1% of the participants were vaccinated. The incidence rate of influenza-like illnesses was 11.3%. Within the influenza-vaccinated group, 12.3% experienced an influenza-like illness. On the other hand, in the non-vaccinated group, 10.2% experienced an influenza-like illness. There was no statistically significant difference in the incidence of influenza-like illness depending on vaccination status. Conclusion: During the influenza season from Fall 2014 to Spring 2015, there was no significant difference on the prevalence of influenza-like illness between the study participants whether they were vaccinated or not. Thus, future studies should confirm and closely examine this fact, whether it was a matter of pandemic strain selection or whether there were differences in the effects of adult influenza vaccination as reported in previous studies.

• Journal of Ginseng Research
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• v.38 no.1
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• pp.40-46
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• 2014

The highly pathogenic (HP) H5N1 influenza virus is endemic in many countries and has a great potential for a pandemic in humans. The immune-enhancing prowess of ginseng has been known for millennia. We aimed to study whether mice and ferrets fed with Red Ginseng could be better protected from the lethal infections of HP H5N1 influenza virus than the infected unfed mice and ferrets. We fed mice and ferrets with Red Ginseng prior to when they were infected with HP H5N1 influenza virus. The mice and ferrets fed with a 60-day diet containing Red Ginseng could be protected from lethal infections by HP H5N1 influenza virus (survival rate of up to 45% and 40%, respectively). Interferon-${\alpha}$ and -${\gamma}$ antiviral cytokines were significantly induced in the lungs of mice fed Red Ginseng, compared to mice fed an unsupplemented diet. These data suggest that the diet with the immune-enhancing Red Ginseng could help humans to overcome the infections by HP H5N1 influenza virus.

• Journal of Ginseng Research
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• v.35 no.1
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• pp.104-110
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• 2011

Korean red ginseng (RG), which is a ginseng treated by heating and steaming, has biological activity similar to Panax ginseng. The effect of ginseng on influenza infection has not been studied although it is known to have a broad range of biological activities. The aim of the study is to investigate the effect of RG extract on influenza A (H1N1) virus infection. We investigated the inhibitory effect of RG extract on plaque formation by influenza A virus in a cell-based plaque assay, and the effect of orally administered RG on influenza A virus infection in mice. RG extract, which was applied at a non-cytotoxic concentration, inhibited plaque formation by influenza A virus in the cell-based plaque assay. The orally administered RG extract ameliorated body weight loss and significantly increased survival in mice infected with influenza A virus. Our results suggest that RG extract has components that reduce the severity of infection by influenza A virus and could potentially be used as a complement to treatment of influenza A virus infections.

• Journal of Microbiology and Biotechnology
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• v.29 no.8
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• pp.1184-1192
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• 2019

The influenza A virus is a highly infectious respiratory pathogen that sickens many people with respiratory disease annually. To prevent outbreaks of this viral infection, an understanding of the characteristics of virus-host interaction and development of an anti-viral agent is urgently needed. The influenza A virus can infect mammalian species including humans, pigs, horses and seals. Furthermore, this virus can switch hosts and form a novel lineage. This so-called zoonotic infection provides an opportunity for virus adaptation to the new host and leads to pandemics. Most influenza A viruses express proteins that antagonize the antiviral defense of the host cell. The non-structural protein 1 (NS1) of the influenza A virus is the most important viral regulatory factor controlling cellular processes to modulate host cell gene expression and double-stranded RNA (dsRNA)-mediated antiviral response. This review focuses on the influenza A virus NS1 protein and outlines current issues including the life cycle of the influenza A virus, structural characterization of the influenza A virus NS1, interaction between NS1 and host immune response factor, and design of inhibitors resistant to the influenza A virus.