• Journal of Life Science
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• v.33 no.8
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• pp.605-611
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• 2023

Recently, sporadic cases of human infection by genetic reassortants of H7Nx influenza A viruses have been reported; such viruses have also been continuously isolated from avian species. In this study, A/wild bird/South Korea/sw-anu/2023, a novel reassortant of the H7N1 avian influenza virus, was analyzed using full-genome sequencing and molecular characterization. Phylogenetic analysis showed that A/wild bird/South Korea/sw-anu/2023 belonged to the Eurasian lineage of H7Nx viruses. The polymerase basic (PB)2, PB1, polymerase acidic (PA), and nucleoprotein (NP) genes of these viruses were found to be closely related to those of avian influenza viruses isolated from wild birds, while the hemagglutinin (HA), neuraminidase (NA), matrix (M), and nonstructural (NS) genes were similar to those of avian influenza viruses isolated from domestic ducks. In addition, A/wild bird/South Korea/sw-anu/2023 also had a high binding preference for avian-specific glycans in the solid-phase direct binding assay. These results suggest the presence of a new generation of H7N1 avian influenza viruses in wild birds and highlight the reassortment of avian influenza viruses found along the East Asian-Australasian flyway. Overall, H7Nx viruses circulate worldwide, and mutated H7N1 avian viruses may infect humans, which emphasizes the requirement for continued surveillance of the H7N1 avian influenza virus in wild birds and poultry.

• 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 dental hygiene science
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• v.9 no.5
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• pp.519-524
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• 2009

This study surveyed the knowledge level, self-efficacy, seriousness in infection, and behavioral intention for H1N1 targeting some undergraduates for the Health Division who are attending university where is located in Metropolitan Area, and surveyed the difference according 10 gender. As a result, the following conclusions were obtained. 1. As for knowledge on H1N1, the highest correct-answer rate was shown in the item as saying that 'New influenza may be possible for person-to-person infection(94.6%).' The item as saying that 'New influenza is what is same as avian influenza(16.3%)' showed the lowest correct-answer rate. The knowledge of H1N1 was indicated to be averagely 7.8 points given making it score. 2. As for self-efficacy on H1N1 according to gender male students were shown to be higher than female students. Thus, there was significant difference(P < 0.05). As for seriousness about infection, female students were indicated 10 think it more serious about infection with H1N1 than male students. Thus, there was significant difference(P < 0.01). As for behavioral intention, the response as saying at 'When an acquaintance is attacked by new influenza, I will try to consider meeting' was indicated to be higher in female students with 3.98 points than male students with 3.79 points. Thus, there was significant difference(P < 0.05).

• Journal of Life Science
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• v.30 no.9
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• pp.749-762
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• 2020

Influenza A viruses are circulating in a variety of hosts, including humans, pigs, and poultry. Swine influenza virus is a zoonotic pathogen that can be readily transmitted to humans. The influenza viruses of the 2009 H1N1 pandemic were derived from swine influenza viruses, and it has been suggested that the 1957 H2N2 pandemic and the 1968 H3N2 pandemic both originated in pigs. Pigs are regarded as a mixing vessel in the creation of novel influenza viruses since they are readily infected with human and avian influenza viruses. We isolated three novel H1N2 influenza viruses from pigs showing respiratory symptoms on a Korean farm in 2019. These viruses were reassortants, containing PA and NP genes from those of the 2009 H1N1 influenza virus in addition to PB2, PB1, HA, NA, M, and NS genes from those of triple-reassortant swine H3N2 and classical swine H1N2 influenza viruses circulating in Korean pigs. Mice infected with the isolated H1N2 influenza virus lost up to 17% body weight and exhibited interstitial pneumonia involving infiltration of many inflammatory cells. Results suggest that close surveillance to detect emerging influenza viruses in pigs is necessary for the health of both pigs and humans.

• Journal of Life Science
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• v.17 no.3 s.83
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• pp.340-344
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• 2007

Avian influenza viruses cause a considerable threat to humans and animals. In this study, we investigated whether alkaline disinfectant solution can inactivate H5N1, H3N2, H6N1, and H9N2 subtypes of avian influenza virus. When H5N1, H3N2, H6N1, and H9N2 avian influenza viruses were treated with alkaline solution diluted with PBS (pH 7.2) prior to infection into MDCK cells, alkaline disinfectant solution (at dilutions up to $10^{-2}$) completely inactivated all avian influenza subtypes tested. To confirm the inactivation of avian influenza viruses by alkaline disinfectant solution, we used an immunofluorescence assay with influenza A anti-nucleoprotein antibody and FITC-labeled secondary antibody to stain MDCK cells infected with avian H9N2 influenza viruses. No staining was observed in MDCK rells infected with H9N2 viruses that were pre-treated with a $10^{-2}$ dilution of alkaline disinfectant solution, while strong staining was observed in MDCK cells infected with H9N2 viruses without pre-treatment. Our results indicate that alkaline solution could help to control avian influenza viruses including the highly pathogenic H5N1 subtype.

• Journal of Life Science
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• v.20 no.3
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• pp.365-373
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• 2010

To monitor newly emerged influenza virus variants and to investigate the prevalence pattern, our laboratory performed isolation of the viruses from surveillance sentinel hospitals. In the present study, we analysed influenza A/H1N1, A/H3N2, B viruses isolated in Busan during the 2006/07 and 2007/08 seasons by sequence analysis of the hemagglutinin (HA1 subunit) and neuraminidase (NA) genes. The isolates studied here were selected by the stratified random sample method from a total of 277 isolates, in which 15 were A/H1N1, 16 were A/H3N2 and 29 were B. Based on the phylogenetic tree, the HA1 gene showed that A/H1N1 isolates had a 96.7% to 97.7% homology with the A/Brisbane/59/2007, A/H3N2 isolates had a 98.4% to 99.7% homology with the A/Brisbane/10/2007, and B isolates had a 96.5% to 99.7% homology with the B/Florida/4/2006(Yamagata lineage), which are all the vaccine strains for the Northern Hemisphere in 2008~2009 season. In the case of the NA gene, A/H1N1 isolates had 97.8% to 98.5% homologies, A/H3N2 isolates had 98.9% to 99.4% homologies, and B isolates had 98.9% to 100% homologies with each vaccine strain in the 2008~2009 season, respectively. Characterization of the hemagglutinin gene revealed that amino acids at the receptor-binding site and N-linked glycosylation site were highly conserved. These results provide useful information for the control of influenza viruses in Busan and for a better understanding of vaccine strain selection.

• Microbiology and Biotechnology Letters
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• v.31 no.4
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• pp.329-333
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• 2003

Influenzavirus were isolated from patients with acute respiratory infections in Busan during 2000-2002 and characterized their antigenic properties. In 2000, 39 viruses were isolated and they were identified as Influenzavirus. Among the isolated influenzavirus, 23 were A type influenzavirus and 16 were B type influenzavirus. As a result of antigenic characterization, the influenzavirus were determined to A/Sydney/05/97 (H3N2)-like, A/Beijing/262/95 (H1N1)-like, and B/Harbin/07/94-like virus. In 2001, 56 viruses were isolated and all of the viruses were identified as influenzavirus. They were A/Panama/2007/99 (H3N2)-like and A/Newcaledonia/20/99 (H1N1)-like virus In 2002, 114 Influenzaviruses were isolated. Among the isolated influenzavirus, 83 were A type influenzaviruses, and 31 were B type influenzaviruses. They were A/Panama/2007/99 (H3N2)-like, A/Newcaledonia/20/99 (H1N1)-like and B/Beijing/243/97, B/Honkong/22/2001, B/Sichuam/379/99-like virus when determined their antigenic properties. These results may be useful for the establishment of reliable epidemic data.

• Pediatric Infection and Vaccine
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• v.18 no.2
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• pp.173-181
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• 2011

Purpose : 2009 Pandemic influenza A (H1N1) virus was identified in March 2009 and subsequently caused worldwide outbreaks. We described the clinical and epidemiological characteristics of H1N1 influenza infection. Methods : We used retrospective medical chart reviews to collect data on the visiting patients from a single institute. H1N1 infection was confirmed in specimens with the use of a RT-PCR (real time reverse transcriptase polymerase chain reaction assay). Result : 6,836 patients had H1N1 RT-PCR test, and 2,781 were confirmed with H1N1 virus infection. 158 patients (5.7%) had hospital treatment and inpatients were significantly younger (5.4${\pm}$3.3 years) than outpatients (7.5${\pm}$3.9 years) among H1N1 virus confirmed patients. Oxygen, steroid, immunoglobulin, ventilator treatment was provided in a substantial proportion among pneumonia patients accompanying wheezy respiration. In addition more intensive care was needed in patients accompanying segmental, lobar, interstitial, mixed pneumonia and lung effusion (27.2%) than patients with bronchopneumonia (7.3%) among H1N1 virus infection confirmed patients. Seventy-one infants had oseltamivir treatment out of 83 infants under 1 year, and no significant side effects and complications were identified. Conclusion : In 2009 pandemic influenza A (H1N1), hospital treatment was needed in younger patients. Early intensive care was needed in pneumonia patients accompanying wheezy respiration, and patients accompanying segmental, lobar, interstitial, mixed pneumonia and lung effusion.

• Journal of Korean Academy of Nursing
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• v.41 no.3
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• pp.403-410
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• 2011

Purpose: This study was to identify the current status of vaccination against the pandemic (H1N1) 2009 virus among university students from the fields of nursing and allied health from a local community and verify factors influencing vaccination. Methods: The study included 227 students in the fields of nursing and allied health from a provincial university. Data were obtained from these participants between May 31 and June 11, 2010 by using self-report questionnaires. Results: The rate of vaccination against the pandemic (H1N1) 2009 virus for these participants was 14.5%. No difference was observed in this regard between majors and school year. Factors that influence vaccination against this virus included previous vaccination against seasonal influenza and participants’ attitudes toward general vaccination. Conclusion: The results suggest that for effective pandemic (H1N1) 2009 vaccination of university students from the fields of nursing and allied health, students who have not been vaccinated should be intensively managed. Developing a vaccination program that encourages a positive attitude toward vaccination is recommended.

• 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.