• Pediatric Infection and Vaccine
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• v.19 no.2
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• pp.61-70
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• 2012

Purpose: This study was performed to compare the clinical characteristics of 2009 pandemic influenza A(H1N1) [A(H1N1) pdm09] and seasonal influenza A infection in the pediatric cancer patients. Methods: A retrospective review was performed in the pediatric cancer patients who had confirmed A(H1N1)pdm09 infection at Samsung Medical Center from August 2009 to February 2010. For the comparison, the medical records of pediatric cancer patients with seasonal influenza A from January 2000 to May 2009 were reviewed retrospectively. Results: Eighty-two A(H1N1)pdm09 infections were confirmed in the pediatric cancer patients. Ten patients (12.2%) developed complicated clinical course by lower respiratory infections or extrapulmonary infections; 4 pneumonia, 1 bronchitis, 1 pericarditis with pneumonia, 1 encephalitis with pneumonia, 2 meningitis and 1 pericarditis. Three patients received mechanical ventilator and ICU care. Three pediatric cancer patients (3.7%) died. The risk factors related to complicated A(H1N1)pdm09 infections were date of infection (44-45th week 2009) and nosocomial infection. When comparing with previous seasonal influenza A infections, more prompt and aggressive antiviral therapy was given in A(H1N1)pdm09 infections. Conclusion: The A(H1N1)pdm09 infections caused a various clinical manifestations including fatal cases in pediatric cancer patient during pandemic season. There was no significant difference in clinical course between influenza A(H1N1)pdm09 and seasonal influenza A infections except the antiviral treatment strategy.

• Journal of Life Science
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• v.9 no.3
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• pp.289-292
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• 1999

This study was performed to monitor the circulation of various influenza virus strains since influenza is one of the commonest respiratory disease in man, its causative virus has been the subjects of extensive research. The authors investigated the epidemics of influenza in Pusan in 1998. Influenza viruses have been isolated from patients with respiratory disease whose ages range from 1 to 68. Virus isolation from female was higher than male. The isolation of virus was mostly concentrated in December in 1998. The isolated virus showed strong cytopathic effect on MDCK cells and identified as influenza A/Sydney/05/97-like(H3N2) and influenza A/Beijing/262/95-like(H1N1). A negative staining of electron micrograph showed 130 nm with H1N1 in diameter, respectively.

• Korean Journal of Veterinary Research
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• v.38 no.1
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• pp.53-63
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• 1998

Total of 1085 swine sera (1996-1997) from nation-wide were tested for the presence of antibodies to influenza A virus. Fifty nine percent of the tested sera showed seropositive by HI test. Positive sera consisted of 24--- of H3, 15--- of H1, and 20--- of the sample had both antibodies, respectively. Sera collected from various region represented 7~27--- seropositivity to H1N1, 15~25--- to H3N2, respectively. Swine influenza field isolate from nasal swab was characterized antigenically and genetically to elucidate its relatedness with other known strains of influenza A virus. The study was focused on the HA gene which is related to pathogenecity and antigenic variability of the influenza virus. By RT-PCR using influenza A/H1N1 specific primers, influenza virus H1N1 specific DNA fragment was amplified from A/Swine/Iowa/15/30(H1N1), US field isolate but not in H3N2 strain. PCR products were sequenced by dideoxy chain termination method to determine nucleotide homology with other strains of influenza A virus. The US field isolate and A/Swine/Indiana/1726/88 strain had 97--- of nucleotide homology and 98--- of amino acid homology. Based on the results obtained from this experiment, the field isolate was genetically related to A/Swine/Indiana/1726/88 and had higher homology with A/Swine/Indiana/1726/88 than with classical swine influenza virus, A/Swine/Iowa/15/30. The field isolate had no amino acid changes at the antigenic site compare to that of the A/Swine/Indiana/1726/88. The proteolytic enzyme cleavage site between HA1 and HA2 had no alteration and the amino acid arginine was intact. There is no evidence has been found that the field isolate has genetic shift or genetic drift which might altered antigenic determinant.

• Tuberculosis and Respiratory Diseases
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• v.70 no.2
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• pp.155-159
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• 2011

Recently, a novel influenza A (H1N1) has been recognized as the cause of a worldwide respiratory infection outbreak. Although the symptoms of a novel influenza A (H1N1) are usually mild, the disease can cause severe illness and death. A complication of novel influenza A (H1N1) is pneumomediastinum, a rarely reported condition. We report a case of influenza A (H1N1) complicating pneumomediastinum with subcutaneous emphysema, which had initially presented with blood tinged sputum and chest pain. In addition, we demonstrate bronchoalveolar lavage in influenza A (H1N1).

• Korean Journal of Microbiology
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• v.55 no.1
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• pp.25-32
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• 2019

Influenza A (H1N1) virus caused a worldwide pandemic in 2009-2010 and still remains in seasonal circulation. Continuous surveillance activities are encouraged in the post pandemic phase to watch over the trend of occurrence every year, this is better to be done by a rapid and sensitive method for its detection. This study was conducted to detect proportions of occurrence of influenza A virus (H1N1) in patients with influenza-like illness. Samples from 500 patients with influenza or influenza-like clinical presentation were tested by real-time reverse transcription polymerase chain reaction (RT-PCR) and virus tissue culture. Among the total 500 participants, 193 (38.6%) were females and 307 (61.4%) males. Seventy-one patients (14.2%) were positive for H1N1 virus infection with real-time RT-PCR while 52 (10.4%) were positive by tissue culture. Non-statistically significant relation was found between age and gender with the positivity of H1N1. Sensitivity and specificity of real-time RT-PCR was 98.08% and 95.54%, respectively, in comparison to virus isolation with accuracy 95.8%. This study showed that H1N1 virus was responsible for a good proportion of influenza during the post-pandemic period. Real-time RT-PCR provides rapidity and sensitivity for the detection of influenza A virus (H1N1) compared with virus isolation and thus it is recommended as a diagnostic tool.

• 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 the Korean Society of School Health
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• v.24 no.1
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• pp.61-70
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• 2011

Purpose: To identify factors associated with children's discriminatory attitudes towards fully recovered children who contracted the 2009 Influenza A (H1N1), in order to provide fundamental information to improve health education for children. Methods: Cross-sectional data were collected from the entire 6th grade classes (N=2,323) of 11 elementary schools randomly selected from 11 school districts in the Seoul Metropolitan Area of South Korea. Questionnaires were used to assess participants' knowledge of and attitudes towards the Influenza A (H1N1) virus. Results: Multiple regression analyses were used to investigate the factors associated with children's discriminatory attitudes toward fully recovered children who had contracted the 2009 Influenza A (H1N1). Multiple regression analysis revealed that perceived risk of contracting and knowledge of 2009 influenza A (H1N1) were significant factors in predicting a child's attitude toward fully recovered Influenza A (H1N1) patients, after controlling for socioeconomic variables. Conclusion: The findings suggests that perceived risk and knowledge play important roles in formulating children's appropriate attitudes towards Novel influenza A (H1N1) patients who are fully recovered from the disease. To promote and maximize children's attitudes in this area, health education needs to be directed at children to reduce excessive concern about contracting the virus and to improve their overall health knowledge.

• Pediatric Infection and Vaccine
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• v.24 no.1
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• pp.23-30
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• 2017

Purpose: The objective of this study was to compare the clinical characteristics of influenza A and B infections and analyze the effect of oseltamivir in hospitalized children. Methods: We investigated children under the age of 15, who were diagnosed with influenza A/H1N1, A/H3N2, or B from January to April 2014. The subjects were admitted to the Changwon Fatima Hospital and diagnosed using a rapid antigen test from nasopharyngeal swabs. The medical records of the patients were retrospectively reviewed. Results: A total of 302 pediatric patients with influenza were enrolled. Influenza B infection was the most common type (n=187, 61.9%), followed by A/H3N2 (n=100, 33.1%) and A/H1N1 (n=15, 5.0%). Compared to patients diagnosed with influenza A, patients diagnosed with influenza B were older (P=0.005), and the duration of fever was significantly longer (P=0.001). A total of 161 patients (53.3%) had been vaccinated against influenza during the season, before admission. Among the patients infected with A/H3N2 and B, the duration of fever was shorter in oseltamivir recipients compared to oseltamivir non-recipients (P=0.026 and P=0.004, respectively). Conclusions: There were significant differences between influenza A and B groups in terms of age, demographics, and clinical course. Although the effectiveness of oseltamivir on influenza differs according to the type of influenza, our data provides evidence that oseltamivir is beneficial for both A and B infections.

• The Journal of Korean Academic Society of Nursing Education
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• v.16 no.2
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• pp.249-256
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• 2010

Purpose: This study was performed to identify the affecting factors on health behavior of university students during pandemic Influenza A (H1N1). Method: The participants in this study were 283 students in H university. Data were collected through self-reported questionnaires in September, 2009. The collected data were analyzed by ANOVA, Pearson correlation and stepwise multiple regression using SPSS/WIN 18.0. Result: The percentage of correct answers regarding knowledge of Influenza A (H1N1) was 34.6%. Risk perception and compliance of health behavior were very poor, $17.92{\pm}6.26/30$ and $2.00{\pm}1.68/9$, respectively. There was a positive correlation among knowledge, risk perception and health behavior. Knowledge and risk perception of Influenza A (H1N1) and intention of getting an influenza vaccination for this year explained 16.3% of variance in health behavior. Conclusion: An educational program focusing on strategy to enhance university students' knowledge and risk perception of Influenza A (H1N1) would be effective in improving their health behavior against it.

• Journal of Korean society of Dental Hygiene
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• v.11 no.3
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• pp.301-311
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• 2011

Objectives : In order to identify the awareness of influenza A (H1N1) having currently high frequency and risk as an infectious disease, to find problems and to reflect them on curriculum improvements from students before/after clinical practices. Methods : The data was collected from 279 dental hygiene students of 1st and 2nd years at G health college university from December 6th 2010 to December 10th 2010. The questionnaire were consisted of awareness of influenza A (H1N1), preventive attitude, sociodemographic characteristics. Results : 1. 1st year was 51.6%, the case having dental experience was 51.2%, in the infection control training experience 'had' was 46.6%. In the route acquiring the information, the mass media was 70.6%, in obtained information, personal hygiene was 82.1%. In the impact on human body, 'great impact' was 58.1%. In terms of the most need for response and preparedness, vaccination was the highest, 67.4%. People who experienced influenza A (H1N1) were 10.7%. 2. Awareness of influenza A (H1N1) was 0.71 points, and treatment and spreading mechanism was 0.78 points, prevention was 0.63 points, causes and definition was 0.53 points. 3. In the attitude for infection prevention of influenza A (H1N1), 'washing hands before practice' was the highest, 0.99 points and 'wear the mask only in case of contact with patient within 1~2 meters upon occurrence of no aerosol' was the lowest, 0.72 points. 4. Awareness of influenza A (H1N1) according to sociodemographic characteristics showed the significant differences upon the impacts on systemic health (p<0.05). Preventive attitude didn't show a significant difference in grade, clinical experience, experience in infection control training, acquiring rmation routes, the possibility for occurrence, impact on systemic health, the most need for prevention, experience in influenza A (H1N1) (p>0.05). 5. The significantly correlated between awareness of influenza A (H1N1) and preventive attitude(p<0.01). Conclusions : Information and preventive attitude for influenza A (H1N1) as well as systematic training programs to identify actual affecting factors and to improve the practice are needed. Also government's institutional support is needed.