#Genetic Characterization of #MERS #Coronavirus, South #Korea, 2018 (Emerg Infect Dis., abstract)

[Source: US Centers for Disease Control and Prevention (CDC), Emerging Infectious Diseases Journal, full page: (LINK). Abstract, edited.]

Volume 25, Number 5—May 2019 / Dispatch

Genetic Characterization of Middle East Respiratory Syndrome Coronavirus, South Korea, 2018

Yoon-Seok Chung, Jeong Min Kim, Heui Man Kim, Kye Ryeong Park, Anna Lee, Nam-Joo Lee, Mi-Seon Kim, Jun Sub Kim, Chi-Kyeong Kim, Jae In Lee, and Chun Kang

Author affiliations: Korea Centers for Disease Control and Prevention, Cheongju, South Korea (Y.-S. Chung, J.M. Kim, H.M. Kim, K.R. Park, A. Lee, N.-J. Lee, M.-S. Kim, J.S. Kim, C.-K. Kim, C. Kang); Seoul Institute of Public Health and Environment, Seoul, South Korea (J.I. Lee)

 

Abstract

We evaluated genetic variation in Middle East respiratory syndrome coronavirus (MERS-CoV) imported to South Korea in 2018 using specimens from a patient and isolates from infected Caco-2 cells. The MERS-CoV strain in this study was genetically similar to a strain isolated in Riyadh, Saudi Arabia, in 2017.

Keywords: MERS-CoV; Saudi Arabia; South Korea.

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#Serosurveillance of #avian #influenza A/ #H5N6 virus #infection in #poultry #farmers, Gyeonggi Province, Republic of #Korea, 2016-2017 (Int J Infect Dis., abstract)

[Source: International Journal of Infectious Diseases, full page: (LINK). Abstract, edited.]

Int J Infect Dis. 2018 Oct;75:49-51. doi: 10.1016/j.ijid.2018.08.002. Epub 2018 Aug 7.

Serosurveillance of avian influenza A/H5N6 virus infection in poultry farmers, Gyeonggi Province, Republic of Korea, 2016-2017.

Ryu S1, Kim CK2, Kim K3, Woo SH2, Chun BC4.

Author information: 1 Division of Infectious Disease Control, Gyeonggi Provincial Government, Suwon, Republic of Korea; Department of Epidemiology and Health Informatics, Graduate School of Public Health, Korea University, Seoul, Republic of Korea. Electronic address: gentryu@onehealth.or.kr. 2 Division of Viral Diseases, Center for Laboratory Control of Infectious Diseases, Korea Centers for Disease Control and Prevention, Cheongju, Republic of Korea. 3 Division of Viral Diseases Research, Center for Infectious Diseases Research, Korea National Institute of Health, Korea Centers for Disease Control and Prevention, Cheongju, Republic of Korea. 4 Department of Epidemiology and Health Informatics, Graduate School of Public Health, Korea University, Seoul, Republic of Korea; Department of Preventive Medicine, Korea University College of Medicine, Seoul, Republic of Korea.

 

Abstract

OBJECTIVES:

Between November 20, 2016 and April 17, 2017, outbreaks of highly pathogenic avian influenza (HPAI) A/H5N6 occurred on poultry farms in Gyeonggi Province in the Republic of Korea. A serosurvey was conducted among poultry farmers to identify the transmission of HPAI A/H5N6 virus to humans.

METHODS:

A descriptive study of 870 poultry farmers in Gyeonggi Province in Korea was conducted during the 2016-2017 outbreaks. Serological testing was performed using a microneutralization (MN) assay for antibodies against influenza A/duck/ES2/Korea/2016 virus, which has antigenic properties similar to those of the HPAI A/H5N6 virus that caused this poultry outbreak.

RESULTS:

Overall, 523 exposed poultry farmers were assessed by serological testing. Consequently, all tested negative for HPAI A/H5N6 virus via MN assay.

CONCLUSIONS:

Based on serological assays, no transmission of HPAI A/H5N6 to humans was identified in this study cohort. Additional studies should be conducted to determine the possibility of poultry-to-human transmission of HPAI A/H5N6.

Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

KEYWORDS: Avian influenza; H5N6; Korea; Poultry; Transmission

PMID: 30096358 DOI: 10.1016/j.ijid.2018.08.002

Keywords: Avian Influenza; H5N6; Human; Serosurveys; S. Korea.

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#Clinical and #Laboratory Findings of #MERS-CoV #infection (Jpn J Infect Dis., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Jpn J Infect Dis. 2018 Dec 25. doi: 10.7883/yoken.JJID.2018.187. [Epub ahead of print]

Clinical and Laboratory Findings of MERS-CoV infection.

Hwang SM1,2,3, Na BJ4, Jung YM5, Lim HS6, Seo JE6, Park SN6, Cho YS6, Song EH6, Seo JY6, Kim SR6, Lee GY6, Kim SJ6, Park YS6, Seo HS3,6.

Author information: 1 Korea Centers for Disease Control and Prevention. 2 Department of Health Policy, Health & Welfare Bureau. 3 Department of Preventive Medicine, Korea University College of Medicine. 4 Department of Preventive Medicine Seoul Metropolitan Government Civil health care bueau. 5 Korea Armed Forces Nursing Academy. 6 Department of Tuberculosis, Seobuk Hospital.

 

Abstract

There is a paucity of data regarding the differentiating characteristics of patients with laboratory confirmed and those negative for Middle East respiratory syndrome coronavirus (MERS-CoV) in South Korea. This is a hospital-based retrospective study comparing MERS-CoV-positive patients with MERS-CoV-negative patients. A total of 7 positive patients and 55 negative patients with a median age of 43 (P = 0.833) were included. No statistical differences were observed in relation to sex and the presence of comorbidities. At the time of admission, headache (28.6% vs 3.6%; OR, 10.60; 95% CI, 1.22-92.27), myalgia (57.1% vs. 9.1%; OR, 13.33; 95% CI, 2.30-77.24), and diarrhea (57.1% vs 14.5%; OR, 7.83; 95% CI, 1.47-41.79) were common among MERS-CoV-positive patients. MERS-CoV patients were more likely to have a low platelet count (164±76.57 vs 240±76.57) and eosinophil (0.27±0.43 vs. 2.13±2.01; p-value<0.001). Chest radiography with diffuse bronchopneumonia was more frequent in MERS-CoV-positive patients than in negative patients (100% vs 62.5%; p-value=0.491). Symptoms of headache, myalgia, and diarrhea, laboratory characteristics of low counts of platelet and eosinophil, Also, chest X-ray revealed that diffuse bronchopneumonia might have enhance the ability to detect which patients were infected with MERS-CoV in South Korea.

KEYWORDS: MERS; coronavirus; pneumonia; radiographic characteristics

PMID: 30584196 DOI: 10.7883/yoken.JJID.2018.187

Keywords: MERS-CoV; Pneumonia; South Korea.

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Prevalence of #SFTS Virus in #Ticks Collected from National #Parks in #Korea (Vector Borne Zoo Dis., abstract)

[Source: Vector-Borne and Zoonotic Diseases, full page: (LINK). Abstract, edited.]

Prevalence of Severe Fever with Thrombocytopenia Syndrome Virus in Ticks Collected from National Parks in Korea

Young-Sun Jo, Jun-Gu Kang, Jeong-Byoung Chae, Yoon-Kyoung Cho, Jeong-Hwa Shin, Weon-Hwa Jheong, and Joon-Seok Chae

Published Online: 27 Nov 2018 / DOI: https://doi.org/10.1089/vbz.2018.2338

 

Abstract

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging viral disease in East Asian countries, including China, Japan, and the Republic of Korea (ROK). The causative agent of SFTS is the SFTS virus (SFTSV), which is transmitted by ticks. To investigate the prevalence of SFTSV in the ROK, a total of 9744 ticks were collected from vegetation in five national parks between July and November 2015. Of the collected adult and nymph ticks, Haemaphysalis longicornis (68.44%) was the most abundant, followed by Haemaphysalis flava (29.66%), Ixodes nipponensis (1.56%), and Amblyomma testudinarium(0.34%). Collected larval ticks were of the genera Haemaphysalis (99.61%) and Ixodes (0.39%). One-step RT-PCR and nested PCR were used to detect SFTSV-specific genes from each individual adult and nymph tick and pooled larval ticks. SFTSV was detected in 4.77% (48/1006) in H. longicornis, 1.15% (5/436) in H. flava, 0% (0/23) in I. nipponensis, and 20% (1/5) in A. testudinarium. The infection rate of SFTSV in adult and nymph ticks was 3.61%. The prevalence of SFTSV in adult and nymph ticks was relatively high, compared with previous reports. In larval ticks, the minimum infection rate was 0.31%. SFTSV was detected in ticks collected from both trail and nontrail areas in the national parks, and up to 800 meters above sea level. The sequences obtained showed 99.4–99.7% homology with SFTS virus S segment sequences from Chinese and Japanese ticks.

Keywords: SFTSV; South Korea; Ticks.

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#Pathogenesis and genetic characteristics of novel #reassortant low-pathogenic #avian #influenza #H7 viruses isolated from migratory #birds in the Republic of #Korea in the winter of 2016-2017 (Emerg Microbes Infect., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Emerg Microbes Infect. 2018 Nov 15;7(1):182. doi: 10.1038/s41426-018-0181-3.

Pathogenesis and genetic characteristics of novel reassortant low-pathogenic avian influenza H7 viruses isolated from migratory birds in the Republic of Korea in the winter of 2016-2017.

Lee YN1, Cheon SH1, Lee EK1, Heo GB1, Bae YC2, Joh SJ2, Lee MH1, Lee YJ3.

Author information: 1 Avian Influenza Research & Diagnostic Division, Animal and Plant Quarantine Agency, 177 Hyeoksin 8-ro, Gimcheon-si, Gyeongsangbuk-do, 39660, Republic of Korea. 2 Avian Disease Division, Animal and Plant Quarantine Agency, 177 Hyeoksin 8-ro, Gimcheon-si, Gyeongsangbuk-do, 39660, Republic of Korea. 3 Avian Influenza Research & Diagnostic Division, Animal and Plant Quarantine Agency, 177 Hyeoksin 8-ro, Gimcheon-si, Gyeongsangbuk-do, 39660, Republic of Korea. leeyj700@korea.kr.

 

Abstract

In this study, we characterized H7 subtype low-pathogenicity (LP) influenza A viruses (IAVs) isolated from wild bird habitats in the Republic of Korea from 2010 to early 2017. Through national surveillance, 104 H7 IAVs were isolated, accounting for an average of 14.9% of annual IAV isolations. In early 2017, H7 subtypes accounted for an unusually high prevalence (43.6%) of IAV detections in wild birds. Phylogenetic analysis revealed that all the viruses isolated in the winter of 2016-2017 fell within cluster II of group C, belonging to the Eurasian lineage of H7 IAVs. Notably, cluster II of group C included the H7 gene from the highly pathogenic H7N7 IAV that was detected in northeastern Italy in April of 2016. Through a gene-constellation analysis, the H7 LPIAVs that we isolated constituted ≥11 distinct genotypes. Because the viruses belonging to the genotypes G2.1 and G1 were observed most frequently, we compared the replication and transmission of representative viruses to these genotypes in specific-pathogen-free chickens. Notably, the representative G2.1 strain was capable of systemic replication and efficient transmission in chickens (as evidenced by virus isolation and histopathological examination) without any clinical signs except mortality (in one infected chicken). The efficient subclinical viral replication and shedding of the G2.1 virus in chickens may facilitate its silent spread among poultry after introduction. Given that wild birds harbor novel strains that could affect poultry, our results highlight the need for enhanced IAV surveillance in both wild birds and poultry in Eurasia.

PMID: 30442892 DOI: 10.1038/s41426-018-0181-3

Keywords: Avian Influenza; H7N7; Reassortant Strain; Wild Birds; Poultry; Italy; S. Korea.

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#Mutations in the #spike protein of #MERS-CoV transmitted in #Korea increase #resistance towards #antibody-mediated neutralization (J Virol., abstract)

[Source: Journal of Virology, full page: (LINK). Abstract, edited.]

Mutations in the spike protein of MERS-CoV transmitted in Korea increase resistance towards antibody-mediated neutralization

Hannah Kleine-Weber, Mahmoud Tarek Elzayat, Lingshu Wang, Barney S. Graham, Marcel A. Müller, Christian Drosten, Stefan Pöhlmann, Markus Hoffmann

DOI: 10.1128/JVI.01381-18

 

ABSTRACT

The Middle East respiratory syndrome coronavirus (MERS-CoV) poses a threat to public health. The virus is endemic in the Middle East but can be transmitted to other countries by travel activity. The introduction of MERS-CoV into the Republic of Korea by an infected traveler resulted in a hospital outbreak of MERS that entailed 186 cases and 38 deaths. The MERS-CoV spike (S) protein binds to the cellular protein DPP4 via its receptor binding domain (RBD) and mediates viral entry into target cells. During the MERS outbreak in Korea emergence and spread of viral variants was observed that harbored mutations in the RBD, D510G and I529T. Counterintuitively, these mutations were found to reduce DPP4 binding and viral entry into target cells. Here, we investigated whether they also exerted pro-viral effects. We confirm that changes D510G and I529T reduce S protein binding to DPP4 but show that this reduction only translates into diminished viral entry when expression of DPP4 on target cells is low. Both mutations did not modulate S protein binding to sialic acids, S protein activation by host cell proteases and inhibition of S protein-driven entry by interferon-induced transmembrane proteins. In contrast, changes D510G and I529T increased resistance of S protein-driven entry to neutralization by monoclonal antibodies and serum from a convalescent MERS patient. These findings indicate that MERS-CoV variants with reduced neutralization sensitivity were transmitted during the Korean outbreak and that the responsible mutations were compatible with robust infection of cells expressing high levels of DPP4.

 

IMPORTANCE

MERS-CoV has pandemic potential and it is important to identify mutations in viral proteins that might augment viral spread. In the course of a large hospital outbreak of MERS in the Republic of Korea in 2015 the spread of a viral variant was observed that contained mutations in the viral spike protein. These mutations were found to reduce receptor binding and viral infectivity. However, it remained unclear whether they also exerted pro-viral effects. We demonstrate that these mutations reduce sensitivity to antibody-mediated neutralization and are compatible with robust infection of target cells expressing high amounts of the viral receptor DPP4.

Copyright © 2018 American Society for Microbiology. All Rights Reserved.

Keywords: MERS-CoV; Human.

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Agent-Based #Modeling for #SuperSpreading #Events: A Case Study of #MERS-CoV #Transmission Dynamics in the Republic of #Korea (Int J Environ Res Public Health, abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Int J Environ Res Public Health. 2018 Oct 26;15(11). pii: E2369. doi: 10.3390/ijerph15112369.

Agent-Based Modeling for Super-Spreading Events: A Case Study of MERS-CoV Transmission Dynamics in the Republic of Korea.

Kim Y1, Ryu H2, Lee S3,4.

Author information: 1 Division of Media Communication, Hankuk University of Foreign Studies, Seoul 02450, Korea. yunhwankim2@gmail.com. 2 Department of Applied Mathematics, Kyung Hee University, Yongin 446-701, Korea. kyinr108@gmail.com. 3 Department of Applied Mathematics, Kyung Hee University, Yongin 446-701, Korea. sunmilee@khu.ac.kr. 4 Institute of Natural Sciences, Kyung Hee University, Yongin 446-701, Korea. sunmilee@khu.ac.kr.

 

Abstract

Super-spreading events have been observed in the transmission dynamics of many infectious diseases. The 2015 MERS-CoV outbreak in the Republic of Korea has also shown super-spreading events with a significantly high level of heterogeneity in generating secondary cases. It becomes critical to understand the mechanism for this high level of heterogeneity to develop effective intervention strategies and preventive plans for future emerging infectious diseases. In this regard, agent-based modeling is a useful tool for incorporating individual heterogeneity into the epidemic model. In the present work, a stochastic agent-based framework is developed in order to understand the underlying mechanism of heterogeneity. Clinical (i.e., an infectivity level) and social or environmental (i.e., a contact level) heterogeneity are modeled. These factors are incorporated in the transmission rate functions under assumptions that super-spreaders have stronger transmission and/or higher links. Our agent-based model has employed real MERS-CoV epidemic features based on the 2015 MERS-CoV epidemiological data. Monte Carlo simulations are carried out under various epidemic scenarios. Our findings highlight the roles of super-spreaders in a high level of heterogeneity, underscoring that the number of contacts combined with a higher level of infectivity are the most critical factors for substantial heterogeneity in generating secondary cases of the 2015 MERS-CoV transmission.

KEYWORDS: 2015 MERS-CoV; agent-based models; basic reproduction number; isolation interventions; super-spreading events

PMID: 30373151 DOI: 10.3390/ijerph15112369

Keywords: MERS-CoV; S. Korea; Nosocomial Outbreaks.

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