Background: Periprosthetic joint infection (PJI) is the most serious complication after total joint arthroplasty. The incidence and burden of PJI in North America have been reported.There might be potential differences according to ethnics and regional practices between western countries and East Asia. Nevertheless, its incidence in East Asia remains unknown.We aimed to evaluate the incidence and economic burden of PJI in Korea and to project the future burden. Methods: We identified numbers of total hip arthroplasties, total knee arthroplasties and PJIs in Korea from 2010 to 2018 using medical claim data of Korean Health Insurance and Review and Assessment. Annual incidence and medical cost of PJI were calculated. We projected future burden of PJI through 2030 using Quasi-poisson regression model. Results: The annual incidence of PJI ranged from 2.3% to 2.8% and the average cost per each PJI patient ranged from $4,361 to $6,016. Total annual cost of PJI increased from $8.0 million in 2010 to $18.0 million in 2018 and was projected to exceed $57.0 million by 2030. Conclusion The incidence of PJI in Korea is comparable with reported PJI incidence of 2.0%–2.7% in the United States. Our findings would be used for worldwide comparison of PJI epidemiology and establishment of healthcare policies for PJI in East Asia.

PURPOSE: To investigate the relationships between tear osmolarity and various parameters for ocular and systemic disease in primary Sjögren's syndrome. METHODS: The medical records of 53 patients with primary Sjögren's syndrome were reviewed. Tear osmolarity using a TearLab® (TearLab™ Corp., San Diego, CA, USA) osmometer as well as other dry eye parameters such as tear break-up time, ocular staining score (Sjögren's International Collaboration Clinical Alliance [SICCA] ocular staining score, SICCA score), Schirmer-I score, symptoms with Ocular Surface Disease Index (OSDI), and Visual Analog Scale (VAS) were obtained. Systemic laboratory data and medication history were also collected. The correlations between the parameters were analyzed using the Spearman's rank correlation test. RESULTS: 53 patients with a mean age of 54.1 ± 13.2 years and female predominance (96.23%) were enrolled. The majority of patients (28.3%) were receiving systemic therapy for severe Sjögren's syndrome. The tear osmolarity in Sjögren's syndrome patients was 307 ± 13.6 (mOsm/L). Higher tear osmolarity was associated with lower tear film break-up time (BUT) scores and with higher SICCA scores. Tear osmolarity and the Schirmer test results were not significantly related. Higher tear osmolarity was paradoxically associated with lower VAS scores and lower OSDI scores. Neither current medication nor the salivary gland focus score showed significant associations with tear osmolarity. Although tear osmolarity was not associated with the SSA-Ro or SSA-LA titer, serum immunoglobulin G (IgG) level and serum erythrocyte sedimentation rate (ESR) level showed positive correlations with tear osmolarity. CONCLUSIONS: Tear osmolarity is positively correlated with the severity of dry eye and was associated with lower symptom severity. The significant associations of tear osmolarity with IgG and ESR suggest that high tear osmolarity may be correlated with autoantibody load and the systemic inflammatory state.
Blood Sedimentation ; Cooperative Behavior ; Dry Eye Syndromes ; Female ; Humans ; Immunoglobulin G ; Medical Records ; Osmolar Concentration* ; Salivary Glands ; Tears* ; Visual Analog Scale

BACKGROUND: Vancomycin-resistant Enterococci (VRE) infections are caused by Enterococcus faecium in about 90% of the cases but can also be caused by Enterococcus faecalis. Thus, this study investigates factors that cause a low isolation rate of vancomycin-resistant E. faecalis (VREfs). To this end, the authors study the clinical traits, resistant gene structure, genomic classification, and molecular characteristics of the virulent factor. METHODS: From January 2001 through September 2011, 17 vanA-containing E. faecalis isolates were collected from hospitalized patients at Ajou University Hospital in Korea. Identification, antimicrobial susceptibility testing, and PCR of van and esp genes were performed. Pulsed-field gel electrophoresis (PFGE) was used for strain typing. PCR and sequencing of the internal regions of Tn1546 were performed for structural analysis of the van gene. RESULTS: Of 4,235 VRE infections, 3,918 (92.5%) were caused by E. faecium, and 95 (2.2%) were caused by E. faecalis. In 67% of VREfs infections, there was a preceding occurrence of E. faecium infection. All isolates were of genotype vanA. Our isolates were divided into three types according to the distribution of IS elements integrated into Tn1546 (types I to IIb). The PFGE results showed no clonal relatedness among isolates. CONCLUSION: Our study found that VREfs infections affect patients who have experienced vancomycin-resistant E. faecium. (VREfm) infection or undergo invasive procedures. The VREfs seems to involve the horizontal transfer of Tn1546 transposon from VREfm.
Classification ; DNA Transposable Elements ; Electrophoresis, Gel, Pulsed-Field ; Enterococcus faecalis* ; Enterococcus faecium ; Enterococcus* ; Epidemiology* ; Genotype ; Humans ; Korea ; Polymerase Chain Reaction

BACKGROUND: Standard protocols are lacking for the preparation of platelet lysates (PL) as an alternative to using fetal bovine serum as a cell culture supplement. This study aimed to establish optimum conditions for preparing PL for use in cell cultures. METHODS: Cell density in three pooled platelet concentrates (PC) were adjusted to 1x10(12)/L and 2x10(12)/L. PL was prepared from PC by 1 to 3 freeze-thaw (FT) cycles. HaCaT cells were cultured in media supplemented with 5% or 10% PL. Cell numbers were estimated using a Cell Counting Kit-8 (CCK-8; Dojindo Laboratories, Japan). Growth factors were quantified by using the Luminex 200 system (Luminex Corporation, USA). RESULTS: Cell proliferation rates in the presence of PLs were similar when prepared from PCs of both cell densities. The rates were higher in media containing 5% PL than 10% PL when prepared by two FT cycles. Concentrations of vascular endothelial growth factor (VEGF), platelet-derived growth factor-AB/BB (PDGF-AB/BB), PDGF-AA, and epidermal growth factor (EGF) were significantly higher in PL prepared from PC with a cell density of 2x10(12)/L than 1x10(12)/L PC. However, only VEGF and PDGF-AA concentrations in PLs were correlated with HaCaT cell counts. CONCLUSIONS: The 5% PL from PC with a cell density of 1x10(12)/L prepared by two FT cycles treatment was the most effective condition that supported steady HaCaT cell proliferation. Our finding may be useful for preparing PL-supplemented cell culture media.
Blood Platelets/chemistry/*metabolism ; Cell Line ; Cell Proliferation/drug effects ; Culture Media/pharmacology ; Epidermal Growth Factor/chemistry/pharmacology ; Humans ; Platelet-Derived Growth Factor/chemistry/pharmacology ; Vascular Endothelial Growth Factor A/chemistry/pharmacology

BACKGROUND: The incidence of fungal infections varies among hospitals and between different time periods. We performed a nationwide survey in Korea to investigate the distribution of yeast and mold species recovered from clinical specimens. METHODS: The distributions of clinical isolates of yeast and mold species obtained from 12 university hospitals between January and December 2011 were evaluated relative to the hospital and specimen type. RESULTS: A total of 39,533 fungal isolates (37,847 yeast and 1,686 mold isolates) were obtained. C. albicans was the predominant species (49.4%) among the yeast isolates from all clinical specimens, followed by C. glabrata (7.2%) and C. tropicalis (6.5%). For 5,248 yeast isolates from sterile body fluids, blood was the most common source of yeasts (71.1%), followed by peritoneal fluid (9.4%). Although C. albicans was the predominant species at all but two hospitals, the rate of non-albicans Candida species varied from 71.2% to 40.1%, depending on the hospital. The yeast species recovered most frequently from the sterile body fluids was C. albicans (41.7%), followed by C. parapsilosis (17.8%) and C. glabrata (14.4%), while that from non-sterile sites was C. albicans (50.7%), followed by C. glabrata (6.0%) and C. tropicalis (5.5%). For mold-forming fungi, Aspergillus species (62.3%) were most common, followed by Trichophyton species (15.4%). Respiratory specimens were the most common source of molds (39.6%), followed by abscesses/wounds (28.4%) and tissues (17.5%). CONCLUSION: The rank order of distribution for different fungal species varied among hospitals and specimen types. Continual national surveillance programs are essential for identifying possible changes in fungal infection patterns.
Ascitic Fluid ; Aspergillus ; Body Fluids ; Candida ; Fungi ; Hospitals, University ; Incidence ; Korea ; Trichophyton ; Yeasts

In July 2010, we identified an outbreak of vancomycin-resistant enterococci (VRE) in our 26-bed neonatal intensive care unit. We performed an epidemiological investigation after clinical cultures of 2 neonates were positive for VRE. Identification, susceptibility testing, and molecular characterization were performed. Cultures of 3 surveillance stool samples of inpatients and 5 environmental samples were positive for VRE. All isolates were identified as Enterococcus faecium containing the vanA gene. Two distinct clones were identified by performing pulsed-field gel electrophoresis. The 2 clones exhibited different pulsotypes, but they represented identical Tn1546 types. Two sequence types, ST18 and ST192, were identified among all of the isolates with multilocus sequence typing. Our investigation determined that the outbreak in the neonatal intensive care unit was caused by 2 genetically different clones. The outbreak may have occurred through clonal spread and horizontal transfer of the van gene.
Anti-Bacterial Agents/pharmacology ; Bacterial Proteins/genetics ; Bacterial Typing Techniques ; Carbon-Oxygen Ligases/genetics ; DNA, Bacterial/analysis ; *Disease Outbreaks ; Electrophoresis, Gel, Pulsed-Field ; Enterococcus faecium/drug effects/*genetics/isolation & purification ; Feces/microbiology ; Genotype ; Gram-Positive Bacterial Infections/diagnosis/epidemiology/*microbiology ; Humans ; Infant, Newborn ; Intensive Care Units, Neonatal ; Male ; Multilocus Sequence Typing ; Vancomycin/pharmacology ; *Vancomycin Resistance

PURPOSE: The aim of this study was to explore participants' experiences and views of a pilot emergency medicine (EM) sub-internship program. METHODS: A pilot 4-week EM sub-internship program involving four academic emergency departments was developed and implemented at the beginning of fourth-year in medical school. Three focus group discussions were separately conducted with ten students, six supervising residents, or four faculty physicians upon completion of the program. Each 60- to 90-minute discussion was recorded, transcribed, and coded by two assessors independently. Contents were thematically analyzed and group interaction examined. RESULTS: The participants identified several strengths of the program, including an opportunity to treat a variety of acute diseases for the first time, an opportunity to apply a symptom-based practice, an opportunity to experience a dynamic workplace, and an opportunity to receive help with career-planning. Commonly identified weaknesses of the program were placed into three categories: 1) not enough bedside teaching time, 2) the workload of the educators, which impacts program efficiency, and 3) a variety of learning experience among the students. Ideas for improving the program included an announcement about the program in advance, the development of faculty skills, the development of new content, and a validation of the evaluation methods and institutional support. CONCLUSION: The EM sub-internship appears to be effective in preparing fourth-year medical students for many of the challenges they will face in the future. However, continuous efforts to strengthen the program are required. These study results will help EM educators develop their own sub-internship program.
Acute Disease ; Clinical Clerkship ; Efficiency, Organizational ; Emergencies ; Emergency Medicine ; Focus Groups ; Humans ; Learning ; Program Evaluation ; Qualitative Research ; Schools, Medical ; Students, Medical

BACKGROUND: The aim of the present study was to determine the population-based prevalence of diabetes mellitus (DM) and prediabetes in a rural district of Daegu City, Korea. METHODS: Between August and November 2003, a community-based health survey of adults aged 20 years and older was performed in the rural district of Dalseong-gun in Daegu City. A total of 1,806 of all eligible individuals agreed to participate. Fasting plasma glucose was measured in all participants. Two hour oral glucose tolerance was measured in the 1,773 participants for whom there was neither an established diagnosis of DM nor evidence of DM according to fasting glucose levels. The prevalence of DM and prediabetes was determined according to the 2003 criteria of the American Diabetes Association. Subjects with prediabetes were classified into one of three categories of glucose intolerance: isolated impaired fasting glucose (IFG); isolated impaired glucose tolerance (IGT); or combined IFG and IGT. RESULTS: The prevalence of DM was 12.2%. The highest prevalence rates were observed in subjects in their seventies. A total of 34.7% of all subjects who were assigned a diagnosis of DM in the present study had not been diagnosed previously. The prevalence of prediabetes was 22.7%. The highest prevalence rates were observed in subjects in their fifties. CONCLUSION: The present study identified prevalence rates of 12.2% for DM (age-standardized prevalence rate [ASR], 6.8%), and 22.7% for prediabetes (ASR 18.5%). These results emphasize the need for community health promotion strategies to prevent or delay the onset of DM in individuals with prediabetes.
Adult ; Aged ; Diabetes Mellitus ; Fasting ; Glucose ; Glucose Tolerance Test ; Health Promotion ; Health Surveys ; Humans ; Korea ; Plasma ; Prediabetic State ; Prevalence

PURPOSE: The normal values for lung resistance and lung capacity of children, as determined by impulse oscillometry (IOS), are different for children of different ethnicities. However, reference values there is no available reference value for Korean preschool children have yet to be determined. The aim of the present study was to determine the normal ranges of IOS parameters in Korean preschool children. METHODS: A total of 133 healthy Korean preschool children were selected from 639 children (aged 3 to 6 years) who attended kindergarten in Seongnam, Gyeonggi province, Korea. Healthy children were defined according to the European Respiratory Society (ERS) criteria. All subjects underwent lung function tests using IOS. The relationships between IOS value (respiratory resistance (Rrs) and reactance (Xrs) at 5 and 10 Hz and resonance frequency (RF)) and age, height, and weight were analyzed by simple linear and multiple linear regression analyses. RESULTS: The IOS success rate was 89.5%, yielding data on 119 children. Linear regression identified height as the best predictor of Rrs and Xrs. Using stepwise multiple linear regressions based on age, height, and weight, we determined regression equations and coefficients of determination (R2) for boys (Rrs5=1.934-0.009xHeight, R2=12.1%; Xrs5=0.774+0.006xHeight-0.002xAge, R2=20.2% and for girls (Rrs5=2.201-0.012xHeight, R2=18.2%; Xrs5=-0.674+0.004xHeight, R2=10.5%). CONCLUSION: This study provides reference values for IOS measurements of normal Korean preschool children. These provide a basis for the diagnosis and monitoring of preschool children with a variety of respiratory diseases.
Airway Resistance ; Child ; Child, Preschool ; Electric Impedance ; Humans ; Korea ; Linear Models ; Lung ; Lung Volume Measurements ; Oscillometry ; Reference Values ; Respiratory Function Tests ; Respiratory System

The Beijing family of Mycobacterium tuberculosis has been emerging in the world. However, there are few nationwide data of genotypic distribution in Korea. This study aimed to identify the genotypic diversity of clinical isolates of M. tuberculosis and to demonstrate the population of Beijing family in Korea. We collected 96 clinical M. tuberculosis isolates from 11 university hospitals nationwide in Korea from 2008 to 2009. We observed 24 clusters in IS6110-RFLP analysis and 19 patterns in spoligotyping. Seventy-five isolates were confirmed to be Beijing family. Two isolates of the K strain and 12 isolates of the K family strain were also found. We found that drug resistance phenotypes were more strongly associated with Beijing family than non-Beijing family (P=0.003). This study gives an overview of the distribution of genotypes of M. tuberculosis in Korea. These findings indicate that we have to pay more attention to control of M. tuberculosis strains associated with the Beijing family.
Drug Resistance, Bacterial ; Genotype ; Humans ; Microbial Sensitivity Tests ; Mycobacterium tuberculosis/*classification/genetics/isolation & purification ; Phenotype ; Polymorphism, Restriction Fragment Length ; Republic of Korea ; Tuberculosis/*epidemiology/genetics/microbiology