Molecular characterization of manganese peroxidases from white-rot fungus Polyporus brumalis

Ryu, Sun-Hwa,Kim, Boyeong,Kim, Myungkil,Seo, Jin-Ho Springer-Verlag 2014 BIOPROCESS AND BIOSYSTEMS ENGINEERING Vol.37 No.3

Children with COVID-19 after Reopening of Schools, South Korea

( Eun Young Kim ),( Boyeong Ryu ),( Eun Kyoung Kim ),( Young-joon Park ),( Young June Choe ),( Hye Kyung Park ),( Eun Kyeong Jeong ) 대한소아감염학회 2020 Pediatric Infection and Vaccine Vol.27 No.3

목적: 국내 초중고 학교 등교재개 이후 소아에서의 코로나바이러스감염증-2019 (코로나19) 사례의 감염경로를 파악하고자 하였다. 방법: 2020년 5월 1일부터 7월 12일까지 국가감염병감시체계에 신고된 3-18세 소아 청소년 코로나19 확진자의 사례조사서 및 역학조사서를 분석하였다. 결과: 2020년 5월 국내 초중고 학교 등교 재개 이후 7월 12일까지 총 127명의 소아 청소년 코로나19 확진자가 신고되었다. 그 중 59명(46%)은 가족 및 친지로부터 전파된 사례였으며 18명(14%)은 학원 및 개인교습 중 전파되었다. 8명(6%)은 다중이용 시설에서 전파되었으며 3명(2%)은 학교에서 전파된 사례였다. 결론: 코로나19 감염예방을 위한 관리체계가 사전에 마련되고 준비된 경우 학교 내 코로나19 전파는 드물게 나타났다. Purpose: To describe pediatric coronavirus disease 2019 (COVID-19) cases after the reopening of schools in the Republic of Korea and their transmission routes. Methods: All case report forms and epidemiologic investigation forms for children aged 3-18 years reported as COVID-19 cases to the National Notifiable Disease Surveillance System from May 1 to July 12, 2020, were reviewed. Results: After the schools were reopened in May 2020, a total of 127 pediatric COVID-19 cases were confirmed until July 12. Of these, 59 children (46%) were exposed to severe acute respiratory syndrome coronavirus 2 through family and relatives, followed by 18 children (14%) through cram schools or private lessons, 8 children (6%) through multi-use facilities, and 3 children (2%) through school. Conclusions: The present data do not suggest an increased risk of COVID-19 transmission in the context of stringent school-based infection prevention measures introduced across the country.

Risk Factors for Sudden Death Within 2 Days After Diagnosis of COVID-19 in Korea

Choi So Young,Ryu Boyeong,Lee Hyun-Ju,Kim Dong-Hwii,Shin Eunjeong,Kim Seong-Sun,Kwon Donghyok 대한의학회 2023 Journal of Korean medical science Vol.38 No.27

Background: We aimed to analyze the risk factors for sudden death after diagnosis of coronavirus disease 2019 (COVID-19) in South Korea and to provide evidence for informing prevention and control interventions for patients at risk of sudden death. Methods: We included 30,302 COVID-19 related deaths registered in the patient management information system (Central Disease Control Headquarters) between January 1, 2021, and December 15, 2022. We collected their epidemiological data recorded by the reporting city, province, or country. We performed multivariate logistic regression analysis to identify risk factors for sudden death after diagnosis of COVID-19. Results: Among the 30,302 deaths, there were 7,258 (24.0%) and 23,044 (76.0%) sudden and non-sudden deaths, respectively. Sudden death means a person who died within 2 days of diagnosis and who did not receive inpatient treatment. Underlying condition, vaccination status, and place of death were significantly associated with the survival period in all age groups. Moreover, region, sex, and prescription were significantly associated with the survival period only in certain age groups. However, reinfection was not significantly associated with the survival period in any age group. Conclusion: To our knowledge, this is the first study on the risk factors for sudden death after a diagnosis of COVID-19, which included age, underlying condition, vaccination status, and place of death. Additionally, individuals aged < 60 years without an underlying condition were at high risk for sudden death. However, this group has relatively low interest in health, as can be seen from the high non-vaccination rate (16.1% of the general population vs. 61.6% of the corresponding group). Therefore, there is a possibility for the presence of an uncontrolled underlying disease in this population. In addition, many sudden deaths occurred due to delayed hospital visits to continue economic activities even after the onset of COVID-19 symptoms (7 days overall vs. 10 days average for the group). In conclusion, ‘continued interest in health’ is a key factor in avoiding sudden death in the economically active group (under 60 years of age).

Pediatric Deaths Associated With Coronavirus Disease 2019 (COVID-19) in Korea

Shin Eunjeong,최영준,Ryu Boyeong,Kim Na-Young,Lee Hyun Ju,Kim Dong Hwi,Kim Seong-Sun,Kwon Donghyok,윤기욱,박수은,최은화,Lee Sangwon,이현주 대한의학회 2023 Journal of Korean medical science Vol.38 No.3

As of September 3, 2022, 5,388,338 coronavirus disease 2019 (COVID-19) cases and 46 deaths (3 in 2021 and 43 in 2022) were reported in children ≤ 18 years in Korea. Cumulative confirmed cases accounted for 67.3% of the population aged ≤ 18 years and case fatality rate was 0.85/100,000. Among 46 fatal cases, 58.7% were male and median age was 7 years. Underlying diseases were present in 47.8%; neurologic diseases (63.6%) and malignancy (13.6%) most common. Only four had history of COVID-19 immunization. COVID-19 associated deaths occurred at median 2 days from diagnosis (range: −1 to 21). Among COVID-19 deaths, 41.3% occurred before admission; 2 before hospital arrival and 17 in the emergency department. Among children whose cause was documented, myocarditis, respiratory and multiorgan failure were most common. COVID-19 associated death was seen early after diagnosis in children and public health policies to provide access to medical care for children with COVID-19 are essential during the pandemic.

코로나19 판데믹 기간 여러 국가에서 발표한 확진자 및 사망자의 보고율에 대한 혈청역학적 비교 연구

이상원(Sangwon Lee),류보영(Boyeong Ryu),박신영(Shin Young Park) 서울대학교 보건환경연구소 2023 보건학논집 Vol.60 No.1

Objectives: The COVID-19 pandemic that began in 2020 is the largest pandemic since the 1918 influenza pandemic, causing significant loss of life worldwide. To accurately understand and prepare for future pandemics, it is important to have a detailed understanding of the number of COVID-19 cases worldwide, as well as an assessment of the reliability of the reported incidence and mortality data from each country. Methods: This study compared COVID-19 incidence, mortality, case fatality rates reported by 11 countries with the COVID-19 infection induced antibody seropositivity rates obtained from 15 surveys conducted in those countries. Results: Based on patient incidence statistics reported by various countries from the start of the pandemic in 2020 up to March 7, 2023, patient incidence and mortality rates are higher in high-income countries and lower in low- and middle-income countries. Conversely, the case fatality rate is lower in high-income countries and higher in low- and middle-income countries. However, it is important to note that these results may be due to different reporting rates in each country. The analysis found that the estimated reporting rates of COVID-19 in low- and middle-income countries were estimated to be between 0.4% and 1.3%, while the estimated reporting rates in high-income countries were estimated to be between 15.1% and 78.5%. Conclusion: Among the high-income countries, those with a high proportion of patients from 2020 to the end of 2021 who required hospitalization had higher case fatality rates.

Herd immunity: challenges and the way forward in Korea

Jiyoung Oh,Sohyun Kim,Boyeong Ryu,Minjoung Shin,Bryan Inho Kim 한국역학회 2021 Epidemiology and Health Vol.43 No.-

Vaccination is considered to be the most effective measure for preventing the spread of coronavirus disease 2019 (COVID-19). Many countries, including of Korea, are focusing on achieving herd immunity with the goal of reaching a vaccination rate of 70-80%. However, achieving herd immunity does not mean eradicating COVID-19, and the following challenges can occur in the process of achieving herd immunity. First, as the vaccination rate is likely to slow down over time, it is necessary to promote the benefits of vaccination through risk communication strategies and provide incentives for those who have been vaccinated. Second, a booster dose may be required depending on future studies on vaccine-induced immunity. Third, since variants capa-ble of evading immunity and with higher transmissibility can emerge, rapid contract tracing and regular community genomic surveillance could help mitigate the impact of new variants. When the impact of COVID-19 is controlled to the level of sea-sonal influenza, the current public health measures that have been strictly imposed on society since the beginning of the pan-demic will no longer be needed. The overall response strategy to COVID-19 will need to change accordingly, based on evalua-tions of the level of population immunity. These changes will include more efficient and targeted contact tracing and eased quarantine measures for vaccinated close contacts and travelers. Mask wearing and a minimum of social distancing will still be required in the journey towards the end of the pandemic. The COVID-19 pandemic will end, but the virus will not disappear.

Urbanization of Scrub Typhus Disease in South Korea

Park, Sang-Won,Ha, Na-Young,Ryu, Boyeong,Bang, Ji Hwan,Song, Hoyeon,Kim, Yuri,Kim, Gwanghun,Oh, Myoung-don,Cho, Nam-Hyuk,Lee, Jong-koo Public Library of Science 2015 PLoS neglected tropical diseases Vol.9 No.5

<▼1><P><B>Background</B></P><P>Scrub typhus is an endemic disease in Asia. It has been a rural disease, but indigenous urban cases have been observed in Seoul, South Korea. Urban scrub typhus may have a significant impact because of the large population.</P><P><B>Methods</B></P><P>Indigenous urban scrub typhus was epidemiologically identified in Seoul, the largest metropolitan city in South Korea, using national notifiable disease data from 2010 to 2013. For detailed analysis of clinical features, patients from one hospital that reported the majority of cases were selected and compared to a historic control group. Chigger mites were prospectively collected in the city using a direct chigger mite-collecting trap, and identified using both phenotypic and 18S rDNA sequencing analyses. Their infection with <I>Orientia tsutsugamushi</I> was confirmed by sequencing the 56-kDa antigen gene.</P><P><B>Results</B></P><P>Eighty-eight cases of urban scrub typhus were determined in Seoul. The possible sites of infection were mountainous areas (56.8%), city parks (20.5%), the vicinity of one’s own residence (17.0%), and riversides (5.7%). Eighty-seven chigger mites were collected in Gwanak mountain, one of the suspected infection sites in southern Seoul, and seventy-six (87.4%) of them were identified as <I>Helenicula miyagawai</I> and eight (9.2%) as <I>Leptotrombidium scutellare</I>. Pooled DNA extracted from <I>H</I>. <I>miyagawai</I> mites yielded <I>O</I>. <I>tsutsugamushi</I> Boryong strain. Twenty-six patients from one hospital showed low APACHE II score (3.4 ± 2.7), low complication rate (3.8%), and no hypokalemia.</P><P><B>Conclusions</B></P><P>We identified the presence of indigenous urban scrub typhus in Seoul, and a subgroup of them had mild clinical features. The chigger mite <I>H</I>. <I>miyagawai</I> infected with <I>O</I>. <I>tsutsugamushi</I> within the city was found. In endemic area, urban scrub typhus needs to be considered as one of the differential febrile diseases and a target for prevention.</P></▼1><▼2><P><B>Author Summary</B></P><P>Scrub typhus is one of the high burdened infectious diseases in endemic rural areas. Our study showed that the disease could be endemic in urban areas. Indigenous urban scrub typhus may also have significant impact in terms of a disease burden and differential diagnosis. A low rate of characteristic eschar and skin rash may make the clinical suspicion more troublesome. Scrub typhus is the 3<SUP>rd</SUP> most frequent notifiable infectious disease in South Korea. Seoul is a densely populated capital city located in northwestern South Korea. We epidemiologically identified indigenous urban cases. A subgroup of them showed mild clinical characteristics. Direct mite collection from a suspected infection site, Mt. Gwanak in Seoul, showed that <I>Helenicula miyagawai</I> (87.4%) and <I>Leptotrombidium scutellare</I> (9.2%) were the dominant species. In addition, <I>O</I>. <I>tsutsugamushi</I>-specific gene, <I>tsa56</I>, was identified in a fraction of the collected <I>H</I>. <I>miyagawai</I>. The 18S rDNA sequencing of the chigger mites was complementarily helpful for the differentiation of species. Our data are from one region, but urban scrub typhus is likely a scenario in endemic areas. Urban areas should be included as possible locations for scrub typhus.</P></▼2>

Characterization of a Novel DWD Protein that Participates in Heat Stress Response in Arabidopsis

Kim, Soon-Hee,Lee, Joon-Hyun,Seo, Kyoung-In,Ryu, Boyeong,Sung, Yongju,Chung, Taijoon,Deng, Xing Wang,Lee, Jae-Hoon Korean Society for Molecular and Cellular Biology 2014 Molecules and cells Vol.37 No.11

Cullin4-RING ubiquitin ligase (CRL4) is a family of multi-subunit E3 ligases. To investigate the possible involvement of CRL4 in heat stress response, we screened T-DNA insertion mutants of putative CRL4 substrate receptors that exhibited altered patterns in response to heat stress. One of the mutants exhibited heat stress tolerance and was named heat stress tolerant DWD1 (htd1). Introduction of HTD1 gene into htd1-1 led to recovery of heat sensitivity to the wild type level, confirming that the decrease of HTD1 transcripts resulted in heat tolerance. Therefore, HTD1 plays a negative role in thermotolerance in Arabidopsis. Additionally, HTD1 directly interacted with DDB1a in yeast two-hybrid assays and associated with DDB1b in vivo, supporting that it could be a part of a CRL4 complex. Various heat-inducible genes such as HSP14.7, HSP21, At2g03020 and WRKY28 were hyper-induced in htd1-1, indicating that HTD1 could function as a negative regulator for the expression of such genes and that these genes might contribute to thermotolerance of htd1-1, at least in part. HTD1 was associated with HSP90-1, a crucial regulator of thermotolerance, in vivo, even though the decrease of HTD1 did not affect the accumulation pattern of HSP90-1 in Arabidopsis. These findings indicate that a negative role of HTD1 in thermotolerance might be achieved through its association with HSP90-1, possibly by disturbing the action of HSP90-1, not by the degradation of HSP90-1. This study will serve as an important step toward understanding of the functional connection between CRL4-mediated processes and plant heat stress signaling.

Risk factors for deaths associated with COVID-19 according to the cause of death classification in Republic of Korea

Na-Young Kim,Seong-Sun Kim,Hyun Ju Lee,Dong Hwi Kim,Boyeong Ryu,Eunjeong Shin,Donghyok Kwon 질병관리본부 2023 Osong Public Health and Research Persptectives Vol.14 No.2

Objectives: This study aimed to classify coronavirus disease 2019 (COVID-19)-related deaths according to whether COVID-19 was listed as the cause of death, and to investigate the differences in demographic characteristics and risk factors for COVID-19 death classifications.Methods: A total of 5,625 deaths in South Korea among patients with confirmed COVID-19 from January 20, 2020 to December 31, 2021 were selected. Excluding false reports and unnatural deaths, 5,597 deaths were analyzed. Based on death report data, deaths were classified according to whether the cause of death was listed as COVID-19 (CD) or not (NCD). The epidemiological characteristics and causes of deaths were investigated using descriptive, univariate, and multivariate statistical analyses. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to analyze the risk factors.Results: The case fatality ratio was 0.89% and increased with age. Additionally, 96.4% of the subjects had an underlying disease, and 53.4% died in winter. The proportion of NCDs was 9.3%, of whom 19.1% died at home and 39.0% were confirmed to have COVID-19 after death. Malignant neoplasms (102/416 vs. 637/4,442; OR, 1.71; 95% CI, 1.36−2.16; p<0.001) were significantly associated with NCD.Conclusion: This is the first study to analyze risk factors by cause of death using COVID-19 death report data in South Korea. These results are expected to be used as evidence for establishing a death monitoring system that can collect timely information in a new infectious disease pandemic.

Detection of Novel Coronavirus on the Surface of Environmental Materials Contaminated by COVID-19 Patients in the Republic of Korea

Lee Sang-Eun,Lee Deog-Yong,Lee Wook-Gyo,Kang ByeongHak,Jang Yoon Suk,Ryu Boyeong,Lee SeungJae,Bahk Hyunjung,Lee Eungyu 질병관리본부 2020 Osong Public Health and Research Persptectives Vol.11 No.3

This study aimed to determine the presence of SARS-CoV-2 on surfaces frequently touched by COVID-19 patients, and assess the scope of contamination and transmissibility in facilities where the outbreaks occurred. In the course of this epidemiological investigation, a total of 80 environmental specimens were collected from 6 hospitals (68 specimens) and 2 “mass facilities” (6 specimens from a rehabilitation center and 6 specimens from an apartment building complex). Specific reverse transcriptase-polymerase chain reaction targeting of RNA-dependent RNA polymerase, and envelope genes, were used to identify the presence of this novel coronavirus. The 68 specimens from 6 hospitals (A, B, C, D, E, and G), where prior disinfection/cleaning had been performed before environmental sampling, tested negative for SARS-CoV-2. However, 2 out of 12 specimens (16.7%) from 2 “mass facilities” (F and H), where prior disinfection/cleaning had not taken place, were positive for SARS-CoV-2 RNA polymerase, and envelope genes. These results suggest that prompt disinfection and cleaning of potentially contaminated surfaces is an effective infection control measure. By inactivating SARS-CoV-2 with disinfection/cleaning the infectivity and transmission of the virus is blocked. This investigation of environmental sampling may help in the understanding of risk assessment of the COVID-19 outbreak in “mass facilities” and provide guidance in using effective disinfectants on contaminated surfaces.