Realistic Estimation of COVID-19Infection by Seroprevalence Surveillance of SARS-CoV-2Antibodies: An Experience From Korea Metropolitan Area From January to May 2022

Background@#Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread globally, leading to the coronavirus disease 2019 (COVID-19) pandemic. Because a significant proportion of the COVID-19 confirmed cases were concentrated in the capital metropolitan area of South Korea, and a large proportion of the population in the area had been adequately vaccinated against COVID-19, we conducted a seroprevalence surveillance study focusing on the residents of the capital metropolitan area in South Korea. @*Methods@#We used a quota-sampling method to obtain blood samples from 1,000 individuals per round, equally stratified across seven age categories and sexes and regions, from five medical institutions located within the capital metropolitan area of South Korea. During five consecutive months (rounds) between January 2022 and May 2022, a total of 5,000 samples were analyzed for anti-spike (S) and anti-nucleocapsid (N) antibodies. @*Results@#High anti-S seropositivity was observed in all age groups, which corresponded to the vaccine coverage during the study period. Both the cumulative incidence based on polymerase chain reaction (PCR) and the estimated seroprevalence based on anti-N seropositivity increased in the fourth and fifth rounds, which corresponded to April 2022 and May 2022. Seroprevalence coincided with the cumulative incidence during the first three rounds, but exceeded from the fourth survey onwards when infection with omicron variants was increased rapidly in Korea. @*Conclusion@#Seroprevalence confirmed the number of infection cases outside of PCR testing-based surveillance. Seroepidemiological surveillance can help us understand vaccine responses and detect hidden infections, thereby providing appropriate public health guidance for achieving population-level immunity.

Increased Apolipoprotein B/ Apolipoprotein A-I Ratio Is Associated With Decline in Lung Function in Healthy Individuals: The Kangbuk Samsung Health Study

Background@#Lung dysfunction and high apolipoprotein B/apolipoprotein A-I (apoB/apoA-I) ratio are both recognized risk factors for cardiovascular disease. However, few studies have examined the association between the apoB/ApoA-I ratio and lung function. Therefore, we investigated whether this ratio is associated with decreased lung function in a large healthy cohort. @*Methods@#We performed a cohort study on 68,418 healthy Koreans (34,797 males, mean age:38.1 years) who underwent a health examination in 2019. ApoB/apoA-I ratio was categorized into quartiles. Spirometric values at the fifth percentile in our population were considered the lower limit of normal (LLN), which was used to define lung function impairment. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs), using the lowest quartile as the reference, were estimated to determine lung function impairment. @*Results@#Mean apoB/apoA-I ratio was 0.67 ± 0.21. Subjects with the highest quartile of this ratio had the lowest predicted forced expiratory volume in one second (FEV1 %) and forced vital capacity (FVC%) after controlling for covariates (P < 0.001). However, FEV1 /FVC ratio was not significantly different among the four quartiles (P = 0.059). Compared with the lowest quartile (Q1, reference), the aORs (95% CI) for FEV1 % < LLN across increasing quartiles (from Q2 to Q4) were 1.216 (1.094–1.351), 1.293 (1.156–1.448), and 1.481 (1.311– 1.672) (P for trend < 0.001), respectively. Similarly, the aORs for FVC% < LLN compared with the reference were 1.212 (1.090–1.348), 1.283 (1.147–1.436), and 1.502 (1.331–1.695) with increasing quartiles (P for trend < 0.001). However, the aORs for FEV1 /FVC < LLN were not significantly different among groups (P for trend = 0.273). @*Conclusion@#High apoB/apoA-I ratio was associated with decreased lung function. However, longitudinal follow-up studies are required to validate our findings.

Benign Cephalic Histiocytosis in a Patient with Neurofibromatosis Type 1 / 대한피부과학회지

Benign cephalic histiocytosis (BCH) is an uncommon subtype of non-Langerhans cell histiocytosis. A 5-month-old boy presented with multiple yellowish facial papules and plaques, which later spread to his trunk and both extremities. Laboratory tests, including lipid profile, were normal. Histological examination revealed non-foamy histiocytes, lymphocytes, and some eosinophils in the dermis. Immunohistochemical staining was positive for CD68and factor XIIIa, but negative for CD1a and S-100. Additionally, the patient developed multiple café-au-lait spots with axillary and inguinal freckling. Next-generation sequencing identified a pathogenic variant of the neurofibromatosis type 1 (NF1) gene. Herein, we report a rare case of BCH in a patient with NF1. Although many cases of NF1 accompanied by juvenile xanthogranuloma have been reported, the association between BCH and NF1 has not been elucidated. However, considering that BCH may be a clinicopathological variant of juvenile xanthogranuloma, an association between the two diseases can be considered.

Establishment of a Maximum Surgical Blood Order Schedule and Red Blood Cell Mean Transfusion Units Per Patient According to Adjacent Diagnosis Related Groups Patient Classification System

Background@#For effective management of blood components, periodic updates of the maximum surgical blood order schedule (MSBOS) using recent data are crucial. This study aimed to establish an updated MSBOS and red blood cell (RBC) mean transfusion units per patient according to the adjacent diagnosis related groups (ADRG) classification system. @*Methods@#This retrospective study was based on an audit of the medical records of inpatients at a tertiary hospital between January and December 2017. We investigated transfusion-related data to establish the MSBOS and determine the RBC mean transfusion units per patient according to the ADRG and compared these updated values with previous data. @*Results@#During the investigated period, a total of 5,607 RBC units were transfused in 17,382 patients. The revised MSBOS was similar to the previous MSBOS in most surgeries. Among the 130 ADRG codes analyzed, 34 codes showed an increase, while 96 codes showed a decrease in RBC mean transfusion units per patient, compared to data from 2007. Overall, the RBC mean transfusion units per patient in 2017 was 0.89 units less compared to that in 2007 after adjusting for age (95% CI: 0.853–0.912). @*Conclusions@#The revised MSBOS was similar to that of the previous versions. However, there were differences in the number of RBC transfusion units used in some surgeries and disease treatments compared to those in the past. Considering the changes within the medical environment, this study highlights the importance of periodic evaluation of MSBOS and RBC transfusion usage.

Comparison of Clinical Utility between Phadiatop Assay and AdvanSureTM AlloScreen

Background@#Multiple Allergo-Sorbent Test (MAST) allows simultaneous detection of specific IgE antibodies using multiple allergens, and it is commonly used for allergy screening. Phadiatop assay (Phadia AB, Sweden), including Phadiatop test and Phadiatop Infant test, is a variant of specific IgE test that covers a mixture of common allergens. We compared the clinical utility of Phadiatop assay with that of the MAST AlloScreen (LG Life Science, Korea). @*Methods@#A total of 218 samples classified by AlloScreen results were collected. Phadiatop test was performed on sera from 61 and 103 aeroallergen-positive and -negative subjects. Phadiatop Infant test was performed on sera from 54 and 103 food and aeroallergen-positive and -negative subjects. When the results of AlloScreen and Phadiatop assay were not identical, we confirmed them using ImmunoCAP (Phadia AB). @*Results@#The concordance rate between AlloScreen and Phadiatop test was 93.2% (κ=0.86, P<0.001). Eleven (6.7%) of 164 specimens showed discrepant results. The results of AlloScreen did not agree with those of ImmunoCAP. The concordance rate between AlloScreen and Phadiatop Infant test was 97.4% (κ=0.945, P <0.001). Four (2.5%) specimens showed negative results in AlloScreen and positive results in Phadiatop Infant test. Three cases were confirmed as positive and one case was not confirmed through ImmunoCAP. @*Conclusions@#There was excellent agreement between AlloScreen and Phadiatop assay. Phadiatop assay accurately detected sensitization to common food and aeroallergen mixes. Therefore, Phadiatop assay is recommended as a screening test for allergic diseases.

Comparison of Clinical Utility between Phadiatop Assay and AdvanSureTM AlloScreen

Background@#Multiple Allergo-Sorbent Test (MAST) allows simultaneous detection of specific IgE antibodies using multiple allergens, and it is commonly used for allergy screening. Phadiatop assay (Phadia AB, Sweden), including Phadiatop test and Phadiatop Infant test, is a variant of specific IgE test that covers a mixture of common allergens. We compared the clinical utility of Phadiatop assay with that of the MAST AlloScreen (LG Life Science, Korea). @*Methods@#A total of 218 samples classified by AlloScreen results were collected. Phadiatop test was performed on sera from 61 and 103 aeroallergen-positive and -negative subjects. Phadiatop Infant test was performed on sera from 54 and 103 food and aeroallergen-positive and -negative subjects. When the results of AlloScreen and Phadiatop assay were not identical, we confirmed them using ImmunoCAP (Phadia AB). @*Results@#The concordance rate between AlloScreen and Phadiatop test was 93.2% (κ=0.86, P<0.001). Eleven (6.7%) of 164 specimens showed discrepant results. The results of AlloScreen did not agree with those of ImmunoCAP. The concordance rate between AlloScreen and Phadiatop Infant test was 97.4% (κ=0.945, P <0.001). Four (2.5%) specimens showed negative results in AlloScreen and positive results in Phadiatop Infant test. Three cases were confirmed as positive and one case was not confirmed through ImmunoCAP. @*Conclusions@#There was excellent agreement between AlloScreen and Phadiatop assay. Phadiatop assay accurately detected sensitization to common food and aeroallergen mixes. Therefore, Phadiatop assay is recommended as a screening test for allergic diseases.

Evaluation of adjacent tooth displacement in the posterior implant restoration with proximal contact loss by superimposition of digital models

PURPOSE: This study was conducted to investigate patterns of adjacent tooth displacement in the posterior implant with interproximal contact loss (ICL) by 3-D digital superimposition method. MATERIALS AND METHODS: Posterior partially edentulous patients, restored with implant fixed partial prostheses before 2011 and suffered from food impaction of ICL between 2009 and 2011, were included. Two dental casts, at the time of delivery and at the time of food impaction in a same patient, was converted into 3-D digital models through scanning and superimposition was performed to assess chronologic changes of the dentition. Directions of tooth displacement were evaluated and the amount of ICL was calculated. Correlations between the amount of ICL and elapsed time, or between the amount of ICL and age after function, were assessed at a significance level of P.05). CONCLUSION: Natural teeth showed various directional movements to result in occlusal change in the arch. The 3-D superimposition of chronologic digital models was a helpful method to analyze the changes of dentition and individual tooth displacement adjacent to implant restoration.

Serotype Distribution and Antimicrobial Resistance of Invasive and Noninvasive Streptococcus pneumoniae Isolates in Korea between 2014 and 2016

BACKGROUND: Several factors contribute to differences in Streptococcus pneumoniae serotype distribution. We investigated the serotype distribution and antimicrobial resistance of S. pneumoniae isolated between 2014 and 2016 in Korea. METHODS: We collected a total of 1,855 S. pneumoniae isolates from 44 hospitals between May 2014 and May 2016, and analyzed the serotypes by sequential multiplex PCR. We investigated the distribution of each serotype by patient age, source of the clinical specimen, and antimicrobial resistance pattern. RESULTS: The most common serotypes were 11A (10.1%), followed by 19A (8.8%), 3 (8.5%), 34 (8.1%), 23A (7.3%), and 35B (6.2%). The major invasive serotypes were 3 (12.6%), 19A (7.8%), 34 (7.8%), 10A (6.8%), and 11A (6.8%). Serotypes 10A, 15B, 19A, and 12F were more common in patients ≤5 years old, while serotype 3 was more common in patients ≥65 years old compared with the other age groups. The coverage rates of pneumococcal conjugate vaccine (PCV)7, PCV10, PCV13, and pneumococcal polysaccharide vaccine 23 were 11.8%, 12.12%, 33.3%, and 53.6%, respectively. Of the 1,855 isolates, 857 (46.2%) were multi-drug resistant (MDR), with serotypes 11A and 19A predominant among the MDR strains. The resistance rates against penicillin, cefotaxime, and levofloxacin were 22.8%, 12.5%, and 9.4%, respectively. CONCLUSIONS: There were significant changes in the major S. pneumoniae serotypes in the community. Non-PCV13 serotypes increased in patients ≤5 years old following the introduction of national immunization programs with the 10- and 13-polyvalent vaccines.

Trends in Bloodstream Infections and Antimicrobial Susceptibilities at a University Hospital in Korea Between 2007 and 2016

BACKGROUND: Blood culture is an important method for identifying infectious microorganisms and confirming that a selected antimicrobial treatment is appropriate. In this study, we investigated the annual changes in the frequencies of blood isolates and antibiotic susceptibility test (AST) results. METHODS: We created a large database comprising data on all patient-unique blood cultures obtained from January 2007 through December 2016. Blood specimens were cultured using the BD BACTEC FX system, and species identification and AST were performed using the VITEK 2 system. RESULTS: During the 10-year study period, a total of 203,651 blood culture results were collected. Of these, gram-positive cocci, gram-negative rods, and fungi were isolated in 2.15%, 0.55%, and 0.12% of the blood cultures, respectively. Escherichia coli was the most commonly isolated species (22.8%), followed by Staphylococcus epidermidis (16.8%), Klebsiella pneumoniae (8.1%), and Staphylococcus aureus (8.0%). Fungal species were isolated in 3.0% of all positive blood cultures. Candida albicans was the most commonly isolated species (1.1%), followed by Candida parapsilosis (0.6%). Methicillin resistance was seen in 55.2% of S. aureus isolates. The frequencies of vancomycin-resistant Enterococcus (VRE) and carbapenem-resistant Pseudomonas aeruginosa (CRPA) were 13.1% and 10.9%, respectively. The isolation rates of MRSA, VRE, and CRPA showed different patterns each year. CONCLUSIONS: Among the isolates, E. coli was the most common, followed by S. epidermidis and K. pneumoniae. This study represents a long-term analysis of bloodstream infections, and the results can be used to identify trends in the microorganisms isolated and their drug resistance.

Occupational Accident Experience by Working Life Cycle of Korean Workers / 한국직업건강간호학회지

PURPOSE@#In this study, we attempted to analyze the occupational accident experience rate by working life cycle of Korean workers considering entrance and turnover in their jobs. The specific goal of this study was to calculate the accident experience rate according to workers' turnover history and previous accident experience.@*METHODS@#We constructed a cumulative data set of 90,338 cases of workers' accident experiences in their jobs from the Fourth Korean Working Conditions Survey. The accident experience rates according to workers' turnover and previous accident experiences were analyzed using descriptive statistics and analysis of variance.@*RESULTS@#In this study, the cumulative accident experience rate of Korean workers was found to be 5.2%. It was confirmed that the accident experience rate of workers increased as the turnover frequencies increased. In addition, we analyzed only the data of the workers who had experienced turnover and found that the accident experience rate after turnover increased about 7.5 times when workers had experienced accidents in the past.@*CONCLUSION@#To prevent occupational accidents in workers, safety strategies should consider a worker's previous job history and injury experiences. It will also be necessary to focus preventive efforts on new and young workers through ongoing monitoring and on-the-job training.