• 대한임상검사과학회지
• /
• 제42권1호
• /
• pp.1-15
• /
• 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.

• 생명과학회지
• /
• 제30권9호
• /
• pp.749-762
• /
• 2020

돼지인플루엔자는 동물에서 사람에게 감염할 수 있는 인수공통전염병이다. 우리는 2019년 한국 돼지농장에서 호흡기 증상을 보이는 돼지에서 3주의 H1N2형 인플루엔자바이러스를 분리하였다. 유전자 분석결과, 이들 바이러스의 8개 유전자 중 PA 및 NP 유전자는 2009 대유행 H1N1 인플루엔자 유래였고, 나머지 유전자는 돼지에 유행하는 H3N2 및 H1N2 인플루엔자 유래 유전자를 가진 재조합 바이러스 이었다. 분리된 H1N2 바이러스를 마우스에 접종한 결과, 마우스는 17% 정도 체중이 감소하였고, 염증 세포들이 침윤한 간질성 폐렴 증상을 보였다.

• 대한수의학회지
• /
• 제38권1호
• /
• pp.53-63
• /
• 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.

• 생명과학회지
• /
• 제9권3호
• /
• pp.289-292
• /
• 1999

1998년 부산지역에서 호흡기 환자의 인후 가검물로부터 분리된 influenza 바이러스 다음과 같은 양사을 볼 수 있었다. 1.분리된 바이러스는 influenza A/Sydney/05/97-like(H3N2)형과 influenza A/Beijing/262/95-like(H1N1)형으로 동정되었다.2.바이러스분리는 4월에서 9월까지를 제외한 모든 달에서 이루어 졌으며 특히 12월에는 집중적인 양상을 보였다.3.연령별로 본 바이러스의 분리는 1세에서 68세까지 전 연령층에서 나타났으며 10세 이하가 가장 높은 분리율을 나타내었다.4.바이러스 분리 비율은 남녀가 1:1.2의 비율로 나타났다.5.분리 바이러스는 MDCK 세포에서 세포병변이 관찰 되었다.6.influenza 바이러스를 Negative staining으로 염색하여 전자현미경으로 관찰한 결과 원형의 바이러스로 in-fluenza A/Sydney/05/97-like(H3N2)는 130 nm,influenza A/Beijing/262/95-like(H1N1) 형은 145nm의 크기로 나타났다.

• 한국동물위생학회지
• /
• 제34권3호
• /
• pp.195-200
• /
• 2011

Swine influenza is an acute respiratory disease prevalent in pig-growing areas all around the world and plays the roles of an intermediate host to be transmitted to mammals including human beings through a genetic recombination with the avian influenza virus. Recognizing that people could be contracted with swine influenza, this study set out to investigate the seroprevalence of individual and multiple infections with two subtypes (H1N1 and H3N2) of the swine influenza virus in pig farms in the Gyeongnam region according to age, area, and season, as well as to provide basic data for the prevention and control of swine influenza. Used in the study were total 904 swine sera that were not vaccinated against the influenza gathered from the pig farms in the Gyeongnam region from November, 2009 to October, 2010. HerdChek SIV (H1N1, H3N2) ELISA kit (IDEXX Laboratories, USA) was used for antibody testing against swine influenza. The test results show that 370 sera (40.9%) were infected with either H1N1 or H3N2 with 37.3% (337 sera) being contracted with H1N1, 13.1% (118 sera) with H3N2, and 9.4% (85) with both H1N1 and H3N2.

• 한국동물위생학회지
• /
• 제45권1호
• /
• pp.31-38
• /
• 2022

Swine influenza (SI) is an important respiratory disease in pigs and epidemic worldwide, which is caused by influenza A virus (IAV) belonging to the family of Orthomyxoviridae. As seen again in the 2009 swine-origin influenza A H1N1 pandemic, pigs are known to be susceptible to swine, avian, and human IAVs, and can serve as a 'mixing vessel' for the generation of novel IAV variants. To this end, the emergence of swine influenza viruses must be kept under close surveillance. Herein, we report the isolation and phylogenetic study of a swine IAV, A/swine/Korea/21810/2021 (sw21810, H3N2 subtype). BLASTN sequence analysis of 8 gene segments of the isolated virus revealed a high degree of nucleotide similarity (94.76 to 100%) to porcine strains circulating in Korea and the United States. Out of 8 genome segments, the HA gene was closely related to that of isolates from cluster I. Additionally, the NA gene of the isolate belonged to a Korean Swine H1N1 origin, and the PB2, PB1, NP and NS genes of the isolate were grouped into that of the Triple reassortant swine H3N2 origin virus. The PA and M genes of the isolate belonged to 2009 Pandemic H1N1 lineage. Human infection with mutants was most common through contact with infected pigs. Our results suggest the need for periodic close monitoring of this novel swine H3N2 influenza virus from a public health perspective.

• Journal of Preventive Medicine and Public Health
• /
• 제52권5호
• /
• pp.308-315
• /
• 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.

• Journal of Microbiology and Biotechnology
• /
• 제28권5호
• /
• pp.809-815
• /
• 2018

Influenza, which is a highly contagious disease caused by the influenza A virus, continues to be a major health concern worldwide. Although the accurate and early diagnosis of influenza virus infection is important for controlling the spread of this disease and rapidly initiating antiviral therapy, the current influenza diagnostic kits are limited by their low sensitivity. In this study, we developed several new influenza nucleoprotein (NP)-specific monoclonal antibodies (mAbs) and compared their sensitivity and specificity of those with commercially available anti-NP mAbs. Three mAbs, designated M24.11, M34.3, and M34.33, exhibited higher reactivities to recombinant NPs and A/Puerto Rico/8/1934 (H1N1) viral lysates compared with the commercial mAbs, as assessed using enzyme-linked immunosorbent assays. M34.3 and M34.33 showed higher reactivities with A/California/04/09 (pandemic H1N1) and A/Philippines/2/82 (H3N2) viral lysates than the commercial mAbs. In contrast, M24.11 had marked reactivity with H3N2 but not with pandemic H1N1. Immunofluorescent confocal microscopy showed that the three mAbs effectively detected the presence of influenza virus in lung tissues of mice infected with A/Puerto Rico/8/1934. These results indicate that the newly developed M34.3 and M34.33 mAbs could be useful for the development of influenza diagnostics.

• Journal of Microbiology and Biotechnology
• /
• 제19권11호
• /
• pp.1470-1474
• /
• 2009

This paper describes the development a of direct multiplex reverse transcription-nested polymerase chain reaction (PCR) method, devised for simultaneous detection and typing of influenza viruses. This method combines the direct reverse transcription reaction without RNA purification with the enhancement of sensitivity and specificity of nested PCR. The method successfully detected three major human influenza viruses: influenza virus A subtype 1 (H1N1) and subtype 3 (H3N2), and influenza B virus (B). The minimum number of virus particles (pfu/ml) necessary for detection in spiked saliva samples was 200 (H1N1), 140 (H3N2), and 4.5 (B). The method's sensitivity and simplicity will be convenient for use in clinical laboratories for the detection and subtyping of influenza and possibly other RNA viruses.

• Genomics & Informatics
• /
• 제20권4호
• /
• pp.46.1-46.7
• /
• 2022

Influenza A virus (IAV) is the most widespread pathogen causing human respiratory infections. Although polymerase chain reaction (PCR)-based methods are currently the most commonly used tools for IAV detection, PCR is not ideal for point-of-care testing. In this study, we aimed to develop a more rapid and sensitive method than PCR-based tools to detect IAV using loop-mediated isothermal amplification (LAMP) technology. We designed reverse-transcriptional (RT)-LAMP primers targeting the hemagglutinin gene. RNAs from reference H1N1 and H3N2 showed specific RT-LAMP signals with the designed primers. We optimized the reaction conditions and developed universal reaction conditions for both LAMP assays. Under these conditions, the detection limit was 50 copies for both RT-LAMP assays. There was no non-specific signal to 19 non-IAV respiratory viruses, such as influenza B virus, coronaviruses, and respiratory syncytial viruses. Regarding the reaction time, a positive signal was detected within 25 min after starting the reaction. In conclusion, our RT-LAMP assay has high sensitivity and specificity for the detection of the H1 and H3 subtypes, making it suitable for point-of-care IAV testing.