Effectiveness of the COVID-19 vaccine in the Honam region of the Republic of Korea

Objectives@#In 2021, the effectiveness of the COVID-19 vaccine was analyzed among people living in the Honam region (Gwangju, Jeollanam-do, Jeollabuk-do, and Jeju) of the Republic of Korea. And we investigated changes in the dominant virus strain. @*Methods@#This study used the data provided by the Korean Ministry of the Interior and Safety for individuals ≥12 years old in the Honam region, and the Integrated Disease and Health Management System of the Korea Centers for Disease Control and Prevention for COVID-19-vaccinated individuals as of December 31, 2021. Statistical analyzes were performed using IBM SPSS ver. 23.0. The occurrence of confirmed cases by vaccination status, the relative risk, and vaccine effectiveness by vaccine type were calculated. @*Results@#In 2021, the COVID-19 vaccination rate in Honam was 88.6%. The overall vaccine effectiveness (after 2 and 3 doses) was 98.7% (p98%, and the effect among persons who received 2 doses was >90% regardless of the vaccine type. Although vaccine effectiveness decreased because of reduced antibody levels over time (as observed in breakthrough infections), receiving a booster dose restored the neutralizing antibody levels.

A Healthcare-Associated Outbreak of HCV Genotype 2a at a Clinic in Seoul

Objectives@#An epidemiological investigation was conducted into a hepatitis C virus (HCV) outbreak at an outpatients clinic in Seoul (2011-2012). The aim of the study was to analyze the scale of infection, identify the source of infection, and route of transmission to prevent hepatitis C transmission in the future. @*Methods@#A retrospective study of the outpatients and health care workers (n = 7,285) in the target outpatient clinic during 2011-2012 was conducted. The history of the study population infection with hepatitis C, electronic medical records, field visits, and health care worker interviews were examined for the period between March 1>st , 2006 and March 25th , 2016. The blood samples were collected and tested for anti-HCV antibodies, HCV RNA and HCV gene in 2016. @*Results@#The rate of anti-HCV positive results was 4.4% in the study population. The risk factors associated with an anti-HCV positive result were ≥ 10 clinic visits, and receiving an invasive procedure including a nerve block and a block of the peripheral branch of the spinal nerve (p < 0.05). There were 112 HCV RNA positive cases out of 320 anti-HCV positive test result cases, amongst which 100 cases had the dominant HCV genotype 2a which formed either 1 cluster (n = 56) or 2 clusters (n = 25). This result indicated exposure to a high-association infection source. @*Conclusion@#Anti-HCV antibodies and genotypic analysis showed an epidemiological association between the outbreak of HCV and invasive procedures performed (2011-2012) at an outpatients clinic in Seoul.

Viral Load Kinetics of SARS-CoV-2 Infection in First Two Patients in Korea

As of February 2020, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak started in China in December 2019 has been spreading in many countries in the world. With the numbers of confirmed cases are increasing, information on the epidemiologic investigation and clinical manifestation have been accumulated. However, data on viral load kinetics in confirmed cases are lacking. Here, we present the viral load kinetics of the first two confirmed patients with mild to moderate illnesses in Korea in whom distinct viral load kinetics are shown. This report suggests that viral load kinetics of SARS-CoV-2 may be different from that of previously reported other coronavirus infections such as SARS-CoV.

Identification of Coronavirus Isolated from a Patient in Korea with COVID-19

ObjectivesFollowing reports of patients with unexplained pneumonia at the end of December 2019 in Wuhan, China, the causative agent was identified as coronavirus (SARS-CoV-2), and the 2019 novel coronavirus disease was named COVID-19 by the World Health Organization. Putative patients with COVID-19 have been identified in South Korea, and attempts have been made to isolate the pathogen from these patients.MethodsUpper and lower respiratory tract secretion samples from putative patients with COVID-19 were inoculated onto cells to isolate the virus. Full genome sequencing and electron microscopy were used to identify the virus.ResultsThe virus replicated in Vero cells and cytopathic effects were observed. Full genome sequencing showed that the virus genome exhibited sequence homology of more than 99.9% with SARS-CoV-2 which was isolated from patients from other countries, for instance China. Sequence homology of SARS-CoV-2 with SARS-CoV, and MERS-CoV was 77.5% and 50%, respectively. Coronavirus-specific morphology was observed by electron microscopy in virus-infected Vero cells.ConclusionSARS-CoV-2 was isolated from putative patients with unexplained pneumonia and intermittent coughing and fever. The isolated virus was named BetaCoV/Korea/KCDC03/2020.

Viral Load Kinetics of SARS-CoV-2 Infection in First Two Patients in Korea

As of February 2020, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak started in China in December 2019 has been spreading in many countries in the world. With the numbers of confirmed cases are increasing, information on the epidemiologic investigation and clinical manifestation have been accumulated. However, data on viral load kinetics in confirmed cases are lacking. Here, we present the viral load kinetics of the first two confirmed patients with mild to moderate illnesses in Korea in whom distinct viral load kinetics are shown. This report suggests that viral load kinetics of SARS-CoV-2 may be different from that of previously reported other coronavirus infections such as SARS-CoV.

Viral Load Kinetics of SARS-CoV-2 Infection in First Two Patients in Korea

As of February 2020, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak started in China in December 2019 has been spreading in many countries in the world. With the numbers of confirmed cases are increasing, information on the epidemiologic investigation and clinical manifestation have been accumulated. However, data on viral load kinetics in confirmed cases are lacking. Here, we present the viral load kinetics of the first two confirmed patients with mild to moderate illnesses in Korea in whom distinct viral load kinetics are shown. This report suggests that viral load kinetics of SARS-CoV-2 may be different from that of previously reported other coronavirus infections such as SARS-CoV.

Development of External Quality Controls for Human Immunodeficiency Virus Antigen/Antibody Tests in Korea

BACKGROUND: Quality control is important for accurate diagnosis of human immunodeficiency virus (HIV) infection, and proficiency testing with external quality controls is an important part of quality control. This study intended to develop and supply customized external quality controls for HIV antigen/antibody testing fitted with currently used reagents for standardization of HIV infection diagnosis and evaluation of HIV testing competency of laboratories in Korea. METHODS: Serological tests and inactivation were performed on the obtained HIV antibody positive plasma. To manufacture quality controls having the required antibody titers, dilution ratio was searched using VIDAS (bioMérieux, France), Architect (Abbott Laboratories, USA), and Cobas 8000 (Roche Diagnostics, Germany) analyzers. Diluted source plasma was divided into aliquots after filtering. Homogeneity and stability of the produced external quality controls were evaluated. RESULTS: The collected HIV antibody positive plasma was confirmed by Western blot. Dilution ratios for source plasma were produced for each analyzer showing signal-to-cut-off 2–3, 5–7, and 15–16 reactivity. Diluted plasma was made to 1 mL aliquots and total set of 1,500 external quality controls for HIV antigen/antibody were manufactured. Produced controls satisfied the required criteria of homogeneity and showed less than 10% coefficient of variation for stability except negative controls. CONCLUSIONS: Customized external quality controls were developed and qualified for HIV testing reagents used in Korea. Continuous external quality control assessment for HIV tests with controls would be required.

Characterization of Gp41 Polymorphisms in the Fusion Peptide Domain and T-20 (Enfuvirtide) Resistance-Associated Regions in Korean HIV-1 Isolates

HIV-1 gp41 is an envelope protein that plays an essential role in virus entry. The mutation of gp41 affects HIV-1 entry and susceptibility to the fusion inhibitor T-20. Therefore, we analyzed the natural polymorphism of gp41 of 163 HIV-1 isolates from T-20-naive Koreans infected with HIV-1. This study of gp41 polymorphisms showed that insertions in the fourth threonine (74.8%) and L7M substitutions (85.3%) were more frequent in the fusion peptide motif in Korean HIV-1 isolates compared with those from other countries. Minor T-20 resistance mutations such as L45M (1.2%), N126K (1.2%), and E137K (6.7%) were detected, but the critical T-20 resistance mutations were not detected in the gp41 HR1 and HR2 regions. In addition, the N42S mutation (12.9%) associated with T-20 hypersusceptibility was detected at a high frequency. These results may serve as useful data for studies considering T-20 for use in the development of a more effective anti-retroviral treatment in Korea.

Recurrent Wheezing After Human Bocavirus Lower Respiratory Tract Illnesses in Early Life / 소아알레르기및호흡기학회지

PURPOSE: Excluding RSV, the relationship between bronchiolitis caused by viruses and the development of wheezing and atopy in childhood has not been well studied. We studied this relationship in children who had bronchiolitis caused by human bocavirus before 2 years of age. METHODS: We retrospectively investigated 2,430 throat swab obstained between January 2005 and December 2007 from pediatric in-patients with acute respiratory tract disease at the Kwangju Christian Hospital. Human bocavirus was detected in 112 patients. A total of 61 patients less than 2 years of age were finally enrolled in this study. Patients were followed up between April and June of 2008. We measured the frequency of wheezing and atopic status using (allergy skin-prick tests, CAP tests and MAST tests). RESULTS: Of the 61 patients, 16 (26.2%) had recurrent wheezing. Of these 16 patients, 8 (13.1%) had Infrequent wheezing (1-2 wheezing episodes) and 8 (13.1%) had frequent wheezing (3 and over wheezing episodes). Of the total 61 patients, 18 (29.5%) completed allergy tests. Of the 18 patients, 10 (55.6%) were sensitized to at least 1 allergen. Recurrent wheezing was significantly associated with the severity of bronchiolitis (mild vs. moderate vs. severe; 9.1% vs. 22.2% vs. 66.7%). CONCLUSION: Human bocavirus-induced bronchiolitis in childhood are an independent risk factor for development of wheezing in childhood and may be associated with an increased risk of allergic sensitization. The most important risk factor for recurrent wheezing is the severity of lower respiratory tract illnesses.

Seroprevalence of measles and mumps antibody among preschool children in Korea, according to their vaccination history / 한국역학회지

PURPOSE: To maintain measles elimination status, we evaluated the seropositivity of measles and mumps according to time interval since the first or second dose of MMR in children aged 4 to 6 years, who are starting communal life. MATERIALS AND METHOD: 2,447 children aged 4 to 6 years were enrolled at 251 public health centers over the period of March to May 2007. Subjects were verified their date of MMR vaccination and then their blood was sampled for serologic test. Measles and mumps IgG antibody was tested by ELISA at Korea CDC. RESULTS: Vaccination coverage was 99.9% in the first dose, 64.9% in the second dose regardless of gender. Seropositivity of measles and mumps was 95.7%, 85.5% in the first dose and 98.7%, 98.1% in the second dose, respectively. The seropositivity of measles was 88.1% in 6-year-olds who did not receive the second dose of MMR. As time since receipt, seropositivity of measles tended to decrease over time and was 93.3% in vaccinees over 48 months after the first dose. CONCLUSION: A first dose MMR at 12-15 months cannot lead to herd immunity. More public information is needed to encourage second dose vaccination before admission to day-care center or kindergarten.

Characterization of Respiratory Viral Infection in Children in Gwangju / 감염과화학요법

BACKGROUND: This investigation was to perform the epidemiological surveillance and genetic analysis on respiratory viral agents from children with acute respiratory infections in Gwangju. MATERIALS AND METHODS: For this study, 3,695 specimens obtained from patients with acute respiratory infections were collected by collaboration with pediatric hospitals in Gwangju between 2005 and 2007. Specimens were screened for 8 respiratory viruses including influenza viruses (IFV), human rhinoviruses (HRV), human coronaviruses (HCoV), adenoviruses (ADV), parainfluenza viruses (PIV), human enteroviruses (HEV), respiratory synthitial viruses (RSV) and human bocaviruses (HBoV). Respiratory viruses were detected using multiplex (RT) PCR with viral specific primers. RESULTS: Out of 3,695 specimens, the ratio of virus detection was 24.9% (919). Overall, HRV (35.5%) and IFV (34.9%) were the most common viruses found, followed by HBoV (14.8%), HCoV (10.6%), RSV (3.7%), ADV (3.4%), PIV (3.2%) and HEV (3.0%). In addition, multiple infections were detected in 80 patients (8.7%). When the prevalence was analyzed according to season, HBoV, IFV and HCoV showed two epidemic points in late spring and early winter. ADV, HRV, RSV PIV and HEV, however, were all found to have only one epidemic point, with RSV being most common during winter and the others being most prominent during spring. CONCLUSIONS: Through this epidemiological surveillance, the respiratory viruses prevalent in children in Gwangju area were investigated. We strongly recommend the development of nationwide policy for the management of prevalent respiratory virus that includes long term collection of data and samples, vaccine development and prevention education of the misuse of antibiotics.

Characterization of Respiratory Viral Infection in Children in Gwangju / 감염과화학요법

BACKGROUND: This investigation was to perform the epidemiological surveillance and genetic analysis on respiratory viral agents from children with acute respiratory infections in Gwangju. MATERIALS AND METHODS: For this study, 3,695 specimens obtained from patients with acute respiratory infections were collected by collaboration with pediatric hospitals in Gwangju between 2005 and 2007. Specimens were screened for 8 respiratory viruses including influenza viruses (IFV), human rhinoviruses (HRV), human coronaviruses (HCoV), adenoviruses (ADV), parainfluenza viruses (PIV), human enteroviruses (HEV), respiratory synthitial viruses (RSV) and human bocaviruses (HBoV). Respiratory viruses were detected using multiplex (RT) PCR with viral specific primers. RESULTS: Out of 3,695 specimens, the ratio of virus detection was 24.9% (919). Overall, HRV (35.5%) and IFV (34.9%) were the most common viruses found, followed by HBoV (14.8%), HCoV (10.6%), RSV (3.7%), ADV (3.4%), PIV (3.2%) and HEV (3.0%). In addition, multiple infections were detected in 80 patients (8.7%). When the prevalence was analyzed according to season, HBoV, IFV and HCoV showed two epidemic points in late spring and early winter. ADV, HRV, RSV PIV and HEV, however, were all found to have only one epidemic point, with RSV being most common during winter and the others being most prominent during spring. CONCLUSIONS: Through this epidemiological surveillance, the respiratory viruses prevalent in children in Gwangju area were investigated. We strongly recommend the development of nationwide policy for the management of prevalent respiratory virus that includes long term collection of data and samples, vaccine development and prevention education of the misuse of antibiotics.

Congenital Prepubic Sinus: A Variant of Urethral Duplication / 대한비뇨기과학회지

Congenital prepubic sinus(CPS) is an extremely rare congenital anomaly of the external genitalia of uncertain etiology. Herein, a case of CPS, where immunohistochemical staining was performed to elucidate the etiology of the sinus, is reported. The results of the immunohistochemical study demonstrated the lining epithelium was transitional proximally and squamous distally. These findings suggest that CPS is a variant form of dorsal urethral duplication.

Human metapneumovirus infection in Korean children / 소아과

PURPOSE: Human metapneumovirus(hMPV) is a respiratory viral pathogen that causes a wide spectrum of illnesses, ranging from asymptomatic infection to severe bronchiolitis. The virus has been identified world widely, but so far it has not been published in Korea. METHODS: We obtained clinical samples by nasopharyngeal aspiration from 218 children hospitalized due to acute lower respiratory tract infections at Soonchunhyang University Hospital in Cheonan from October, 2004 to April, 2005. We designed specific primers from conserved region of fusion glycoprotein of hMPV. Total RNA was extracted and RT-PCR was performed, and single specific 423 bp product was obtained. The PCR product was confirmed to be fusion glycoprotein RNA by sequencing. RESULTS: We detected hMPV in 15(6.9 percent) of the 218 hospitalized children. The infected children comprised nine boys and six girls; their mean age was 2.8 years(5 mo-12 yrs) and they were diagnosed with pneumonia(60 percent), bronchiolitis(33.3 percent), croup(6.6 percent). The number of cases of detected hMPV in Korea increased dramatically during the period from March to May 2005. CONCLUSION: hMPV is circulating in Korean children and is associated with respiratory tract infection. Additional studies are required to define the epidemiology and the extent of diseases in the general population caused by hMPV.

Development of Measles Immunoglobulin M Detecting Enzyme-Linked Immunosorbent Assay (IgM ELISA) Using Recombinant Nucleoprotein of Measles Virus

Rapid and reliable diagnosis of measles is important to establish an appropriate therapy and to monitor the epidemic. However, classical ELISA methods using purified virus or virus-infected cells as antigens are not only difficult to determine optimal condition for diagnosis but also highly expensive to establish routine and appropriate diagnostic systems. Nucleoprotein of measles virus is one of the major antigens of measles virus that evoke initial IgM responses. It can be used as an attractive antigen for sero-diagnosis of measles during early infection. To develop simple and inexpensive diagnostic method for measles, we expressed a recombinant nucleoprotein (60-kDa) and a fragmented portion of the nucleoprotein (50-kDa) in E. coli and evaluated their appropriateness as diagnostic antigens. The proteins strongly reacted with sera from measles patients but not with normal control sera. Efficiency of recombinant nucleoprotein-ELISA (rN-ELISA) to detect IgM was compared that of whole measles virus-ELISA (MV-ELISA) on the basis of a clinical diagnosis. In rN-ELISA, sensitivity was 73.8% and agreement was above 76.4%. In MV-ELISA, sensitivity was 76.9% and agreement was 79.2%. Therefore, efficacy of rN-ELISA seemed to be similar to that of MV-ELISA. In addition, we compared with Edmonston rN-ELISA and Korean isolate rN-ELISA on the basis of commercial MV-ELISA. In Edmonston rN-ELISA, sensitivity was 94.0% and agreement was 98.4%. In the case of Korean isolate rN-ELISA, sensitivity was 96.0% and agreement was 96.9%. Thus, there was no significant difference in the efficacy between Edmonston rN-ELISA and Korean isolate rN-ELISA. Furthermore, the correlation coefficient (R2) between Edmonston rN-ELISA and Korean isolate rN-ELISA was 0.9925. These results suggest both Edmonston and Korean isolate rN-ELISA may be useful to diagnose measles.

Cloning and Sequence Analysis of the Full-length cDNA of Coxsackievirus B3 Isolated in Korea

We have determined and analyzed the full-length cDNA sequence of a coxsackievirus B3 (CVB3) Korean isolate (CVB3-Korea/97) which has been known as a general human pathogen. The whole genome contains 7,400 nucleotides and has a single large open reading frame with 6,555 nucleotides that encodes a potential polyprotein precursor of 2,185 amino acids. The genome also contains a 5' non-coding region (NCR) of 741 bases and a 3' NCR of 104 bases followed by poly(A) tail. Sequence homologies of nucleotides and deduced amino acids between the CVB3-Korea/97 strain and the prototype (Nancy strain) were 81.7% and 91.5%, respectively. The genes encoding the functional proteins including viral protease and RNA dependent RNA polymerase showed higher homology than those encoding the structural proteins. We have further analyzed the sequences of 5' NCR, VP1 and VP2 of CVB3-Korea/97, which are known as cardiovirulent determining factors at the nucleotide and amino acid levels. Although the CVB 3-Korea/97 strain was isolated from an aseptic meningitis patient without cardiomyopathy, its 234th nucleotide and 165th amino acid were uracil and Asn as same as those of other cardiovirulent strains one. However, the 155th amino acid of VR1, which closely associated with cardiovirulence, was replaced with Arg155 by single nucleoptide substitution from A2916 to T2916. Moreover, additional amino acid substitutions were observed in the flanking region of Asp155. Taken together, aminoacid(s) substitution in VP1 may play a critical role in determining cardiovirulence of the CVB3-Korea/97 strain rather than individual nucleotide replacements in the 5' NCR and/or an amino acid substitution in VP2.

An Epidemiological Study of Enteroviruses as Causative Agents of Aseptic Meningitis between 1993 and 1998 in Korea / 감염

BACKGROUND: To investigate the epidemiology of aseptic meningitis in Korea, we have isolated and characterized enteroviruses isolated from patients with acute meningitis from 1993 to 1998. METHODS: Stool and/or cerebrospinal fluid (CSF) samples from patients with aseptic meningitis were inoculated onto enterovirus-susceptible cell lines. The virus propagation was examined by the presence of cytopathic effects and each viral isolate was further characterized using a neutralization test. RESULTS: Out of 1,127 specimens, 197 enteroviral isolates were obtained mostly from stool samples (82.8 %) of children aged zero to ten years. At least 15 serotypes of enteroviruses, including echoviruses (EV) 3, 6, 7, 9, 25 and 30, coxsackieviruses (CV) B1~B6, and vaccine-derived polioviruses (PV) had circulated during the previous 6 years. The major serotypes that caused outbreaks of aseptic meningitis, were EV30 in 1997 and EV6 in 1998. Although the incidence of virus isolation peaked during summer, we had isolated enteroviruses all the year round in 1998. CONCLUSION: Since 1993, we had confirmed 197 cases of enteroviral meningitis. Outbreaks of aseptic meningitis were mainly caused by EVs, with peaks during the summer months. Our data emphasize that the nationwide surveillance of aseptic meningitis should be expanded and maintained throughout the year.

An Epidemiological Study of Enteroviruses as Causative Agents of Aseptic Meningitis between 1993 and 1998 in Korea / 감염

BACKGROUND: To investigate the epidemiology of aseptic meningitis in Korea, we have isolated and characterized enteroviruses isolated from patients with acute meningitis from 1993 to 1998. METHODS: Stool and/or cerebrospinal fluid (CSF) samples from patients with aseptic meningitis were inoculated onto enterovirus-susceptible cell lines. The virus propagation was examined by the presence of cytopathic effects and each viral isolate was further characterized using a neutralization test. RESULTS: Out of 1,127 specimens, 197 enteroviral isolates were obtained mostly from stool samples (82.8 %) of children aged zero to ten years. At least 15 serotypes of enteroviruses, including echoviruses (EV) 3, 6, 7, 9, 25 and 30, coxsackieviruses (CV) B1~B6, and vaccine-derived polioviruses (PV) had circulated during the previous 6 years. The major serotypes that caused outbreaks of aseptic meningitis, were EV30 in 1997 and EV6 in 1998. Although the incidence of virus isolation peaked during summer, we had isolated enteroviruses all the year round in 1998. CONCLUSION: Since 1993, we had confirmed 197 cases of enteroviral meningitis. Outbreaks of aseptic meningitis were mainly caused by EVs, with peaks during the summer months. Our data emphasize that the nationwide surveillance of aseptic meningitis should be expanded and maintained throughout the year.

Pregnancy outcome following early exposure to maternal GnRH agonist in controlled ovarian hyperstimulation / 대한산부인과학회잡지

No abstract available.

Phase II trial of sequential VP-16, cisplatin combination chemotherapy and radiotherapy for locally advanced (stage III) non-small cell lung cancer / 대한암학회지

No abstract available.