Current Situation and Control Strategies of H9N2 Avian Influenza in South Korea

Mingeun Sagong 대한수의학회 2023 Journal of Veterinary Science Vol.24 No.1

The H9N2 avian influenza (AI) has become endemic in poultry in many countries since the 1990s, which has caused considerable economic losses in the poultry industry. Considering the long history of the low pathogenicity H9N2 AI in many countries, once H9N2 AI is introduced, it is more difficult to eradicate than high pathogenicity AI. Various preventive measures and strategies, including vaccination and active national surveillance, have been used to control the Y439 lineage of H9N2 AI in South Korea, but it took a long time for the H9N2 virus to disappear from the fields. By contrast, the novel Y280 lineage of H9N2 AI was introduced in June 2020 and has spread nationwide. This study reviews the history, genetic and pathogenic characteristics, and control strategies for Korean H9N2 AI. This review may provide some clues for establishing control strategies for endemic AIV and a newly introduced Y280 lineage of H9N2 AI in South Korea.

Development and characterization of stable cell lines constitutively expressing the porcine reproductive and respiratory syndrome virus nucleocapsid protein

Mingeun Sagong,박최규,Seong-Hee Kim,Sung-Up Moon,Seong-Cheol Cho,이창희 대한수의학회 2010 Journal of Veterinary Science Vol.11 No.2

Despite global efforts to control porcine reproductive and respiratory syndrome virus (PRRSV) infection, the virus continues to cause economic problems in the swine industry worldwide. In this study, we attempted to generate and characterize a panel of stable BHK cell lines that constitutively express the nucleocapsid (N) protein of type 1 or type 2 PRRSV. The established BHK cell lines were found to react well with N-specific antibodies as well as the hyperimmune serum of pigs raised against each genotype of PRRSV. Taken together, the data implicate a potential usefulness for the newly generated stable cell lines as a diagnostic reagent for PRRSV serology.

Development of a Novel Korean H9-Specific rRT-PCR Assay and Its Application for Avian Influenza Virus Surveillance in Korea

Sagong Mingeun,Kang Yong-Myung,Kim Na Yeong,Noh Eun Bi,Heo Gyeong-Beom,An Se-Hee,Lee Youn-Jeong,Choi Young Ki,Lee Kwang-Nyeong 한국미생물학회 2023 The journal of microbiology Vol.61 No.10

Since the 2000s, the Y439 lineage of H9N2 avian influenza virus (AIV) has been the predominant strain circulating in poultry in Korea; however, in 2020, the Y280 lineage emerged and spread rapidly nationwide, causing large economic losses. To prevent further spread and circulation of such viruses, rapid detection and diagnosis through active surveillance programs are crucial. Here, we developed a novel H9 rRT-PCR assay that can detect a broad range of H9Nx viruses in situations in which multiple lineages of H9 AIVs are co-circulating. We then evaluated its efficacy using a large number of clinical samples. The assay, named the Uni Kor-H9 assay, showed high sensitivity for Y280 lineage viruses, as well as for the Y439 lineage originating in Korean poultry and wild birds. In addition, the assay showed no cross-reactivity with other subtypes of AIV or other avian pathogens. Furthermore, the Uni Kor-H9 assay was more sensitive, and had higher detection rates, than reference H9 rRT-PCR methods when tested against a panel of domestically isolated H9 AIVs. In conclusion, the novel Uni Kor-H9 assay enables more rapid and efficient diagnosis than the “traditional” method of virus isolation followed by subtyping RT-PCR. Application of the new H9 rRT-PCR assay to AI active surveillance programs will help to control and manage Korean H9 AIVs more efficiently.

Development and validation of concentration methods for sensitive detection of avian influenza virus in environmental water

Nayeong Kim,Kwang-Nyeong Lee,Mingeun Sagong,Gyeong-Beom Heo,Youn-Jeong Lee 한국예방수의학회 2022 예방수의학회지 Vol.46 No.4

Wild birds, especially aquatic birds, are the natural reservoir of avian influenza virus (AIV), and many kinds of water body can be contaminated with feces of these birds. Seasonally, AIVs can be dissolved in the environmental water from the feces of the infected birds, and this water can be a target for viral detection and identification. In this study, we employed and tested three different filters for concentrating AIV, and it was shown that high concentration factor in terms of viral density could be achieved with viral samples diluted with natural water. Wild bird fecal samples containing low pathogenicity H5 AIVs were successfully concentrated with the adsorption and elution method using mixed cellulose esters membrane; the recovery rate of virus was 35.5 % and the concentration factor was about 50 on average. For the larger volume of water sample, we proved that an inline disposable filter with high surface area, 300 cm2, has a comparable concentration factor to the adsorption and elution method and the filter could be used in the field conveniently by being plugged into peristaltic pump. These validated methods for water sampling may be used as a supplementary for virological surveillance on wild migratory birds or during the epidemiological investigation on the environment near affected premises by AIV.

Characterization of a novel Reassortant H5N6 highly pathogenic avian influenza virus clade 2.3.4.4 in Korea, 2017

( Eun-kyoung Lee ),( Yu-na Lee ),( Soo-jeong Kye ),( Mingeun Sagong ),( Gyeong-beom Heo ),( Yong-myung Kang ),( Hyun-kyu Cho ),( Hyun-mi Kang ),( Sun-ha Cheon ),( Myoung-heon Lee ),( Yong-joo Kim ),( 대한인수공통전염병학회 2018 창립총회 및 학술대회 초록집 Vol.2018 No.1

Introduction: Highly pathogenic avian influenza (HPAI) viruses of the H5 subtype remain a serious concern for both poultry and human health. The clade 2.3.4.4 H5 viruses have evolved into four genetic groups (nominally designated A, B, C and D). Clade 2.3.4.4.A and B H5N8 viruses appear to have been re-introduced from poultry into wild bird populations, likely in Asia and then spread globally through wild bird migration during 2014-2015 (2.3.4.4.A) and 2016-2017 (2.3.4.4.B). In Korea, large epizootics in poultry have been caused by clade 2.3.4.4.A H5N8 viruses since 2014. Then in late 2016, outbreaks in poultry resulted from clade 2.3.4.4.C H5N6 and clade 2.3.4.4.B H5N8 HPAI viruses. In this study, we reported novel reassortant H5N6 HPAI viruses isolated from wild birds and poultry in November 2017. Materials and Methods: In November 2017, we detected two novel H5N6 HPAI viruses through our active surveillance program for avian influenza. On November 17, an H5N6 HPAI virus was detected in a broiler duck farm in Gochang of Jeonbuk Province (A/duck/Korea/HD1/2017(H5N6)). The second H5N6 virus was isolated from fecal samples taken from a wild mallard (Anas platyrhynchos) collected in Jeju on November 27 (A/mallard/Korea/Jeju-H24/2017(H5N6)). AIVs were subtyped using RT-PCR and DNA sequencing. We inferred maximum likelihood (ML) phylogenetic trees for each gene segment using IQ-TREE, 1.5.5.5 and ModelFinder and obtained branch supports with SH-like approximate likelihood ratio test (aLRT) and standard non-parametric bootstrap with 1000 replications. Results: The two isolates shared 99.69~100% nucleotide homology across all eight genes. Results of Blast searching revealed that these novel H5N6 viruses were reassortants with H5 genes most genetically similar to clade 2.3.4.4.B viruses derived from European H5N8 HPAI viruses circulating during the 2016-2017 epizootic and N6 genes of a Eurasian LPAI vvrus lineage circulating in wild birds. Furthermore, both the NP and NA genes were most similar to the H5N6 reassortant virus isolated from a chicken in Greece during this epizootic. The novel clade 2.3.4.4.B H5N6 viruses were phylogenetically distinguishable from the clade 2.3.4.4 viruses (H5N6 and H5N8) previously isolated in Korea during 2016-2017. Conclusions: The genetic analysis showed that these isolates had been generated through reassortment events between European H5N8 HPAI viruses in 2016/2017, which were descendants of Russia-Mongolia H5N8 viruses, and Eurasian lineage LPAI viruses. The novel H5N6 viruses with similar gene constellation were founded in both Greece and Korea, potentially derived by new reassortant events in Eurasian wild bird population at breeding sites or staging sites and then spread to multiple geographic regions through different migratory sub-populations. More detailed information on HPAI viruses identified through active surveillance programs throughout Eurasia is needed to better evaluate the ecology, evolution, dynamics and diffusion of these viruses in wild birds, particularly in breeding sites in Mongolia and Siberia

Avian influenza Surveillance in wild bird in Korea between 2015 and 2016

( Gyeong-beom Heo ),( Eun-kyoung Lee ),( Yu-na Lee ),( Youn-jeong Lee ),( Mingeun Sagong ),( Myoung-heon Lee ),( Yong-joo Kim ) 대한인수공통전염병학회 2018 창립총회 및 학술대회 초록집 Vol.2018 No.1

Introduction: National surveillance of avian influenza virus (AIV) in Korea has been annually conducted for early detection of highly pathogenic avian influenza (HPAI). In Korea, there have been four times of outbreaks of H5N1 HPAI between 2003 and 2011. During 2014-2015, large epizootics in poultry have been caused by H5N8 HPAI viruses. In this study, we report on the result of a nationwide surveillance for AIV in wild birds in Korea between 2015 and 2016. Methods: Samples were collected by the Livestock Health Control Association and regional veterinary offices. The feces of wild birds were collected in major migratory habitats. Healthy migratory birds were captured and oropharyngeal/cloacal swabs were collected from these birds. Each sample was screened by real-time PCR. AIVs were isolated by inoculation on embryonated SPF chicken egg with samples and the presence of AIV was determined using a hemagglutination assay. For sutyping of AIV, HA and NA genes of the AIV isolates were amplified with gene-specific primers using RT-PCR and confirmed by directly sequencing. Results: Between 2015 and 2016, 28,849 samples were collected from wild birds. Of these, 24,091 of wild bird feces, 4,686 from captured birds, and 72 dead birds. A total of 228 viruses were isolated and the various subtypes were found including H1-H12. The major subtypes were H5 (n=59), H6 (n=39), H4 (n=33) and H3 (n=30). H5 AIV was further classified into four NA subtypes: H5N3 (n=23), H5N6 (n=18), H5N8 (n=16) and H5N9 (n=2). H5N6 and H5N8 subtypes were isolated in wild bird feces (n=18), captured bird (n=10), and dead bird (n=6), respectively. These viruses belonged to clade 2.3.4.4 and confirmed as HPAI virus. The H5N6 HPAI viruses isolated in late 2016 were phylogenetically distinguishable from the clade 2.3.4.4 H5N8 HPAI viruses previously isolated in Korea during 2014-2015. Conclusion: Between 2015 and 2016, viruses of various subtypes, including H5 HPAIVs and LPAIV, were isolated from wild bird through AI surveillance. AI Surveillance in wild birds should be enhanced for earlier detection of AIV introduced by wild birds to implement the effective control measure to prevent HPAI outbreaks in poultry farms.

Novel reassortants of clade 2.3.4.4 H5N6 highly pathogenic avian influenza viruses possessing genetic heterogeneity in South Korea in late 2017

Yu-Na Lee,천선하,Soo-Jeong Kye,Eun-Kyoung Lee,Mingeun Sagong,Gyeong-Beom Heo,강용명,Hyun-Kyu Cho,Yong-Joo Kim,Hyun-Mi Kang,이명헌,Youn-Jeong Lee 대한수의학회 2018 Journal of Veterinary Science Vol.19 No.6

Novel H5N6 highly pathogenic avian influenza viruses (HPAIVs) were isolated from duck farms and migratory bird habitats in South Korea in November to December 2017. Genetic analysis demonstrated that at least two genotypes of H5N6 were generated through reassortment between clade 2.3.4.4 H5N8 HPAIVs and Eurasian low pathogenic avian influenza virus in migratory birds in late 2017, suggesting frequent reassortment of clade 2.3.4.4 H5 HPAIVs and highlighting the need for systematic surveillance in Eurasian breeding grounds.