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7 "Cheon-Kwon Yoo"
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Brief Report
Genomic Surveillance of SARS-CoV-2: Distribution of Clades in the Republic of Korea in 2020
Ae Kyung Park, Il-Hwan Kim, Junyoung Kim, Jeong-Min Kim, Heui Man Kim, Chae young Lee, Myung-Guk Han, Gi-Eun Rhie, Donghyok Kwon, Jeong-Gu Nam, Young-Joon Park, Jin Gwack, Nam-Joo Lee, SangHee Woo, Jin Sun No, Jaehee Lee, Jeemin Ha, JeeEun Rhee, Cheon-Kwon Yoo, Eun-Jin Kim
Osong Public Health Res Perspect. 2021;12(1):37-43.   Published online February 23, 2021
DOI: https://doi.org/10.24171/j.phrp.2021.12.1.06
  • 3,999 View
  • 168 Download
  • 12 Citations
AbstractAbstract PDF

Since a novel beta-coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported in December 2019, there has been a rapid global spread of the virus. Genomic surveillance was conducted on samples isolated from infected individuals to monitor the spread of genetic variants of SARS-CoV-2 in Korea. The Korea Disease Control and Prevention Agency performed whole genome sequencing of SARS-CoV-2 in Korea for 1 year (January 2020 to January 2021). A total of 2,488 SARS-CoV-2 cases were sequenced (including 648 cases from abroad). Initially, the prevalent clades of SARS-CoV-2 were the S and V clades, however, by March 2020, GH clade was the most dominant. Only international travelers were identified as having G or GR clades, and since the first variant 501Y.V1 was identified (from a traveler from the United Kingdom on December 22nd, 2020), a total of 27 variants of 501Y.V1, 501Y.V2, and 484K.V2 have been classified (as of January 25th, 2021). The results in this study indicated that quarantining of travelers entering Korea successfully prevented dissemination of the SARS-CoV-2 variants in Korea.

Original Articles
2019 Tabletop Exercise for Laboratory Diagnosis and Analyses of Unknown Disease Outbreaks by the Korea Centers for Disease Control and Prevention
Il-Hwan Kim, Jun Hyeong Jang, Su-Kyoung Jo, Jin Sun No, Seung-Hee Seo, Jun-Young Kim, Sang-Oun Jung, Jeong-Min Kim, Sang-Eun Lee, Hye-Kyung Park, Eun-Jin Kim, Jun Ho Jeon, Myung-Min Choi, Boyeong Ryu, Yoon Suk Jang, Hwami Kim, Jin Lee, Seung-Hwan Shin, Hee Kyoung Kim, Eun-Kyoung Kim, Ye Eun Park, Cheon-Kwon Yoo, Sang-Won Lee, Myung-Guk Han, Gi-Eun Rhie, Byung Hak Kang
Osong Public Health Res Perspect. 2020;11(5):280-285.   Published online October 22, 2020
DOI: https://doi.org/10.24171/j.phrp.2020.11.5.03
  • 3,339 View
  • 86 Download
AbstractAbstract PDF
Objectives

The Korea Centers for Disease Control and Prevention has published “A Guideline for Unknown Disease Outbreaks (UDO).” The aim of this report was to introduce tabletop exercises (TTX) to prepare for UDO in the future.

Methods

The UDO Laboratory Analyses Task Force in Korea Centers for Disease Control and Prevention in April 2018, assigned unknown diseases into 5 syndromes, designed an algorithm for diagnosis, and made a panel list for diagnosis by exclusion. Using the guidelines and laboratory analyses for UDO, TTX were introduced.

Results

Since September 9th, 2018, the UDO Laboratory Analyses Task Force has been preparing TTX based on a scenario of an outbreak caused by a novel coronavirus. In December 2019, through TTX, individual missions, epidemiological investigations, sample treatments, diagnosis by exclusions, and next generation sequencing analysis were discussed, and a novel coronavirus was identified as the causal pathogen.

Conclusion

Guideline and laboratory analyses for UDO successfully applied in TTX. Conclusions drawn from TTX could be applied effectively in the analyses for the initial response to COVID-19, an ongoing epidemic of 2019 – 2020. Therefore, TTX should continuously be conducted for the response and preparation against UDO.

Genome-Wide Identification and Characterization of Point Mutations in the SARS-CoV-2 Genome
Jun-Sub Kim, Jun-Hyeong Jang, Jeong-Min Kim, Yoon-Seok Chung, Cheon-Kwon Yoo, Myung-Guk Han
Osong Public Health Res Perspect. 2020;11(3):101-111.   Published online May 14, 2020
DOI: https://doi.org/10.24171/j.phrp.2020.11.3.05
  • 11,115 View
  • 488 Download
  • 49 Citations
AbstractAbstract PDF
Objectives

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan, China, in December 2019 and has been rapidly spreading worldwide. Although the causal relationship among mutations and the features of SARS-CoV-2 such as rapid transmission, pathogenicity, and tropism, remains unclear, our results of genomic mutations in SARS-CoV-2 may help to interpret the interaction between genomic characterization in SARS-CoV-2 and infectivity with the host.

Methods

A total of 4,254 genomic sequences of SARS-CoV-2 were collected from the Global Initiative on Sharing all Influenza Data (GISAID). Multiple sequence alignment for phylogenetic analysis and comparative genomic approach for mutation analysis were conducted using Molecular Evolutionary Genetics Analysis (MEGA), and an in-house program based on Perl language, respectively.

Results

Phylogenetic analysis of SARS-CoV-2 strains indicated that there were 3 major clades including S, V, and G, and 2 subclades (G.1 and G.2). There were 767 types of synonymous and 1,352 types of non-synonymous mutation. ORF1a, ORF1b, S, and N genes were detected at high frequency, whereas ORF7b and E genes exhibited low frequency. In the receptor-binding domain (RBD) of the S gene, 11 non-synonymous mutations were observed in the region adjacent to the angiotensin converting enzyme 2 (ACE2) binding site.

Conclusion

It has been reported that the rapid infectivity and transmission of SARS-CoV-2 associated with host receptor affinity are derived from several mutations in its genes. Without these genetic mutations to enhance evolutionary adaptation, species recognition, host receptor affinity, and pathogenicity, it would not survive. It is expected that our results could provide an important clue in understanding the genomic characteristics of SARS-CoV-2.

Brief Reports
Emergence of Norovirus GII.17-associated Outbreak and Sporadic Cases in Korea from 2014 to 2015
Sunyoung Jung, Bo-Mi Hwang, HyunJu Jung, GyungTae Chung, Cheon-Kwon Yoo, Deog-Yong Lee
Osong Public Health Res Perspect. 2017;8(1):86-90.   Published online February 28, 2017
DOI: https://doi.org/10.24171/j.phrp.2017.8.1.12
  • 2,418 View
  • 22 Download
  • 7 Citations
AbstractAbstract PDF

Human norovirus are major causative agent of nonbacterial acute gastroenteritis. In general, genogroup (G) II.4 is the most prominent major genotype that circulate in human population and the environment. However, a shift in genotypic trends was observed in Korea in December 2014. In this study, we investigated the trend of norovirus genotype in detail using the database of Acute Diarrhea Laboratory Surveillance (K-EnterNet) in Korea. GII.17 has since become a major contributor to outbreaks of norovirus-related infections and sporadic cases in Korea, although the reason for this shift remain unknown.

Occurrence of Norovirus GII.4 Sydney Variant-related Outbreaks in Korea
Sunyoung Jung, Bo-Mi Hwang, Hyun Ju Jeong, Gyung Tae Chung, Cheon-Kwon Yoo, Yeon-Ho Kang, Deog-Yong Lee
Osong Public Health Res Perspect. 2015;6(5):322-326.   Published online October 31, 2015
DOI: https://doi.org/10.1016/j.phrp.2015.10.004
  • 1,581 View
  • 17 Download
  • 7 Citations
AbstractAbstract PDF
Human noroviruses are major causative agents of food and waterborne outbreaks of nonbacterial acute gastroenteritis. In this study, we report the epidemiological features of three outbreak cases of norovirus in Korea, and we describe the clinical symptoms and distribution of the causative genotypes. The incidence rates of the three outbreaks were 16.24% (326/2,007), 4.1% (27/656), and 16.8% (36/214), respectively. The patients in these three outbreaks were affected by acute gastroenteritis. These schools were provided unheated food from the same manufacturing company. Two genotypes (GII.3 and GII.4) of the norovirus were detected in these cases. Among them, major causative strains of GII.4 (Hu-jeju-47-2007KR-like) were identified in patients, food handlers, and groundwater from the manufacturing company of the unheated food. In the GII.4 (Hu-jeju-47-2007KR-like) strain of the norovirus, the nucleotide sequences were identical and identified as the GII.4 Sydney variant. Our data suggests that the combined epidemiological and laboratory results were closely related, and the causative pathogen was the GII.4 Sydney variant strain from contaminated groundwater.
Epidemics of Norovirus GII.4 Variant in Outbreak Cases in Korea, 2004–2012
Sunyoung Jung, Hyun Ju Jeong, Bo-Mi Hwang, Cheon-Kwon Yoo, Gyung Tae Chung, Hyesook Jeong, Yeon-Ho Kang, Deog-Yong Lee
Osong Public Health Res Perspect. 2015;6(5):318-321.   Published online October 31, 2015
DOI: https://doi.org/10.1016/j.phrp.2015.10.002
  • 1,687 View
  • 19 Download
  • 1 Citations
AbstractAbstract PDF
Norovirus GII.4 is recognized as a worldwide cause of nonbacterial outbreaks. In particular, the GII.4 variant occurs every 2–3 years according to antigenic variation. The aim of our study was to identify GII.4 variants in outbreaks in Korea during 2004–2012. Partial VP1 sequence of norovirus GII.4-related outbreaks during 2004–2012 was analyzed. The partial VP1 sequence was detected with reverse transcription-polymerase chain reaction, seminested polymerase chain reaction, and nucleotide sequence of 312-314 base pairs for phylogenetic comparison. Nine variants emerged in outbreaks, with the Sydney variant showing predominance recently. This predominance may persist for at least 3 years, although new variants may appear in Korea.
Original Article
Enteric Bacteria Isolated from Diarrheal Patients in Korea in 2014
Nan-Ok Kim, Su-Mi Jung, Hae-Young Na, Gyung Tae Chung, Cheon-Kwon Yoo, Won Keun Seong, Sahyun Hong
Osong Public Health Res Perspect. 2015;6(4):233-240.   Published online August 31, 2015
DOI: https://doi.org/10.1016/j.phrp.2015.07.005
  • 1,720 View
  • 18 Download
  • 10 Citations
AbstractAbstract PDFSupplementary Material
Objectives
The aim of this study was to characterize the pathogens responsible for causing diarrhea according to season, region of isolation, patient age, and sex as well as to provide useful data for the prevention of diarrheal disease.
Methods
Stool specimens from 14,886 patients with diarrhea were collected to identify pathogenic bacteria from January 2014 to December 2014 in Korea. A total of 3,526 pathogenic bacteria were isolated and analyzed according to season, region of isolation, and the age and sex of the patient.
Results
The breakdown of the isolated pathogenic bacteria were as follows: Salmonella spp. 476 (13.5%), pathogenic Escherichia coli 777 (22.0%), Vibrio parahaemolyticus 26 (0.74%), Shigella spp. 13 (0.37%), Campylobacter spp. 215 (6.10%), Clostridium perfringens 508 (14.4%), Staphylococcus aureus 1,144 (32.4%), Bacillus cereus 356 (10.1%), Listeria monocytogenes 1 (0.03%), and Yersinia enterocolitica 10 (0.3%). The isolation rate trend showed the highest ratio in the summer season from June to September for most of the pathogenic bacteria except the Gram-positive bacteria. The isolation rate of most of the pathogenic bacteria by patient age showed highest ratio in the 0–19 year age range. For isolation rate by region, 56.2% were isolated from cities and 43.8% were isolated from provinces.
Conclusion
Hygiene education should be addressed for diarrheal disease-susceptible groups, such as those younger than 10 years, aged 10–19 years, and older than 70 years, and monitoring for the pathogens is still required. In addition, an efficient laboratory surveillance system for infection control should be continued.

PHRP : Osong Public Health and Research Perspectives