OBJECTIVES: Although the nationwide inoculation rate of varicella vaccine was approximately 95% in Korean children recently, the number of notified varicella cases is unexpectedly continuously increasing till now. To suggest some hypotheses regarding this discrepancy, an age-period-cohort (APC) analysis as a descriptive epidemiology study was conducted for children residing in Jeju-do, Korea.METHODS: The raw data were obtained from the nationwide database for insurance claim of healthcare fee provided by the National Health Insurance Service, Korea. The selection criteria were children aged 2–13 years who visited any healthcare center due to varicella from 2005 to 2016 while residing in Jeju-do. After calculating the birth cohort-specific crude incidence rates by age and year, the intrinsic estimator method was used to perform the APC analysis.RESULTS: As the annual crude incidence rates decreased with increasing age between 2005 and 2016, the age and period effects also decreased. The intrinsic estimator coefficients suggesting the cohort effect shifted from positive to negative in 2011, the starting year of free varicella vaccine program in Jeju-do.CONCLUSIONS: The results suggested that inoculated varicella vaccines have preventive effects. However, further studies to evaluate waning immunity would be needed.
Chickenpox Vaccine ; Chickenpox ; Child ; Cohort Effect ; Delivery of Health Care ; Epidemiology ; Fees and Charges ; Humans ; Immunization Programs ; Immunization Schedule ; Incidence ; Insurance ; Jeju-do ; Korea ; Measles-Mumps-Rubella Vaccine ; Methods ; National Health Programs ; Parturition ; Patient Selection ; Vaccines

OBJECTIVES: Jeju Province is well known as the region showing the highest incidence of severe fever with thrombocytopenia syndrome (SFTS) in South Korea. The aim of this study was to evaluate the epidemiological and clinical characteristics of SFTS patients in Jeju Province. METHODS: The primary data for this study were obtained from the Integrated Diseases and Health Control System of the Korea Centers for Disease Control and Prevention (KCDCIS). The selection criteria were confirmed cases of SFTS with a residence listed in Jeju Province at the time of diagnosis, reported to the KCDCIS between July 16, 2014 and November 30, 2018. RESULTS: Of 55 confirmed cases of SFTS, the case fatality rate was 10.9% (95% confidence interval [CI], 4.1 to 22.2). The most common presenting symptoms at diagnosis of severe fever, myalgia, and diarrhea had incidences of 83.6% (95% Cl, 71.2 to 92.2), 45.5% (95% Cl, 32.0 to 59.5), and 40.0% (95% CI, 27.0 to 54.1), respectively. CONCLUSIONS: Compared to SFTS patients nationwide in 2013-2015, the subjects of this study exhibited a lower case fatality rate and had a lower incidence of severe fever, myalgia, and confusion.
Bunyaviridae Infections ; Centers for Disease Control and Prevention (U.S.) ; Diagnosis ; Diarrhea ; Fever ; Humans ; Incidence ; Korea ; Mortality ; Myalgia ; Patient Selection ; Thrombocytopenia ; Tick-Borne Diseases

OBJECTIVES: Outbreaks of scarlet fever in Mexico in 1999, Hong Kong and mainland China in 2011, and England in 2014-2016 have received global attention, and the number of notified cases in Korean children, including in Jeju Province, has also increased since 2010. To identify relevant hypotheses regarding this emerging outbreak, an age-period-cohort (APC) analysis of scarlet fever incidence was conducted among children in Jeju Province, Korea. METHODS: This study analyzed data from the nationwide insurance claims database administered by the Korean National Health Insurance Service. The inclusion criteria were children aged ≤14 years residing in Jeju Province, Korea who received any form of healthcare for scarlet fever from 2002 to 2016. The age and year variables were categorized into 5 groups, respectively. After calculating the crude incidence rate (CIR) for age and calendar year groups, the intrinsic estimator (IE) method was applied to conduct the APC analysis. RESULTS: In total, 2345 cases were identified from 2002 to 2016. Scarlet fever was most common in the 0-2 age group, and boys presented more cases than girls. Since the CIR decreased with age between 2002 and 2016, the age and period effect decreased in all observed years. The IE coefficients suggesting a cohort effect shifted from negative to positive in 2009. CONCLUSIONS: The results suggest that the recent outbreak of scarlet fever among children in Jeju Province might be explained through the cohort effect. As children born after 2009 showed a higher risk of scarlet fever, further descriptive epidemiological studies are needed.
Child ; China ; Cohort Effect ; Delivery of Health Care ; Disease Outbreaks ; England ; Epidemiologic Studies ; Exotoxins ; Female ; Hong Kong ; Humans ; Incidence ; Insurance ; Korea ; Methods ; Mexico ; National Health Programs ; Scarlet Fever ; Streptococcus pyogenes

OBJECTIVES: Although the nationwide inoculation rate of varicella vaccine was approximately 95% in Korean children recently, the number of notified varicella cases is unexpectedly continuously increasing till now. To suggest some hypotheses regarding this discrepancy, an age-period-cohort (APC) analysis as a descriptive epidemiology study was conducted for children residing in Jeju-do, Korea. METHODS: The raw data were obtained from the nationwide database for insurance claim of healthcare fee provided by the National Health Insurance Service, Korea. The selection criteria were children aged 2–13 years who visited any healthcare center due to varicella from 2005 to 2016 while residing in Jeju-do. After calculating the birth cohort-specific crude incidence rates by age and year, the intrinsic estimator method was used to perform the APC analysis. RESULTS: As the annual crude incidence rates decreased with increasing age between 2005 and 2016, the age and period effects also decreased. The intrinsic estimator coefficients suggesting the cohort effect shifted from positive to negative in 2011, the starting year of free varicella vaccine program in Jeju-do. CONCLUSIONS: The results suggested that inoculated varicella vaccines have preventive effects. However, further studies to evaluate waning immunity would be needed.
Chickenpox Vaccine ; Chickenpox* ; Child* ; Cohort Effect ; Delivery of Health Care ; Epidemiology ; Fees and Charges ; Humans ; Immunization Programs ; Immunization Schedule ; Incidence* ; Insurance ; Jeju-do* ; Korea* ; Measles-Mumps-Rubella Vaccine ; Methods ; National Health Programs ; Parturition ; Patient Selection ; Vaccines

OBJECTIVES: Jeju Province is well known as the region showing the highest incidence of severe fever with thrombocytopenia syndrome (SFTS) in South Korea. The aim of this study was to evaluate the epidemiological and clinical characteristics of SFTS patients in Jeju Province. METHODS: The primary data for this study were obtained from the Integrated Diseases and Health Control System of the Korea Centers for Disease Control and Prevention (KCDCIS). The selection criteria were confirmed cases of SFTS with a residence listed in Jeju Province at the time of diagnosis, reported to the KCDCIS between July 16, 2014 and November 30, 2018. RESULTS: Of 55 confirmed cases of SFTS, the case fatality rate was 10.9% (95% confidence interval [CI], 4.1 to 22.2). The most common presenting symptoms at diagnosis of severe fever, myalgia, and diarrhea had incidences of 83.6% (95% Cl, 71.2 to 92.2), 45.5% (95% Cl, 32.0 to 59.5), and 40.0% (95% CI, 27.0 to 54.1), respectively. CONCLUSIONS Compared to SFTS patients nationwide in 2013-2015, the subjects of this study exhibited a lower case fatality rate and had a lower incidence of severe fever, myalgia, and confusion.

OBJECTIVES: Outbreaks of scarlet fever in Mexico in 1999, Hong Kong and mainland China in 2011, and England in 2014-2016 have received global attention, and the number of notified cases in Korean children, including in Jeju Province, has also increased since 2010. To identify relevant hypotheses regarding this emerging outbreak, an age-period-cohort (APC) analysis of scarlet fever incidence was conducted among children in Jeju Province, Korea. METHODS: This study analyzed data from the nationwide insurance claims database administered by the Korean National Health Insurance Service. The inclusion criteria were children aged ≤14 years residing in Jeju Province, Korea who received any form of healthcare for scarlet fever from 2002 to 2016. The age and year variables were categorized into 5 groups, respectively. After calculating the crude incidence rate (CIR) for age and calendar year groups, the intrinsic estimator (IE) method was applied to conduct the APC analysis. RESULTS: In total, 2345 cases were identified from 2002 to 2016. Scarlet fever was most common in the 0-2 age group, and boys presented more cases than girls. Since the CIR decreased with age between 2002 and 2016, the age and period effect decreased in all observed years. The IE coefficients suggesting a cohort effect shifted from negative to positive in 2009. CONCLUSIONS The results suggest that the recent outbreak of scarlet fever among children in Jeju Province might be explained through the cohort effect. As children born after 2009 showed a higher risk of scarlet fever, further descriptive epidemiological studies are needed.

OBJECTIVES: Although the nationwide inoculation rate of varicella vaccine was approximately 95% in Korean children recently, the number of notified varicella cases is unexpectedly continuously increasing till now. To suggest some hypotheses regarding this discrepancy, an age-period-cohort (APC) analysis as a descriptive epidemiology study was conducted for children residing in Jeju-do, Korea. METHODS: The raw data were obtained from the nationwide database for insurance claim of healthcare fee provided by the National Health Insurance Service, Korea. The selection criteria were children aged 2–13 years who visited any healthcare center due to varicella from 2005 to 2016 while residing in Jeju-do. After calculating the birth cohort-specific crude incidence rates by age and year, the intrinsic estimator method was used to perform the APC analysis. RESULTS: As the annual crude incidence rates decreased with increasing age between 2005 and 2016, the age and period effects also decreased. The intrinsic estimator coefficients suggesting the cohort effect shifted from positive to negative in 2011, the starting year of free varicella vaccine program in Jeju-do. CONCLUSIONS The results suggested that inoculated varicella vaccines have preventive effects. However, further studies to evaluate waning immunity would be needed.

Background: In the Korean medical system, the severity classification for a specific disease depends primarily on its nationwide admission rate in tertiary hospitals. Inversely, one of the important designation criteria for a tertiary hospital is the hospital's treatment ratio of patients classified as having a specific severe disease. Most diseases requiring pediatric orthopaedic surgery (POS) are not currently classified as high severity in terms of disease severity. We investigated the admission rates for the representative POS diseases in tertiary hospitals and compared these rates with those for adult orthopaedic surgery (AOS) diseases. Methods: Seven POS diagnoses and three AOS diagnoses were selected based on frequency of admission. Nationwide sample data were used to investigate the admission rates for these representative diagnoses from 2008 to 2017. Results: Six of the seven frequent POS diagnoses presented high admission rates in tertiary hospitals (62.5–92.3%). In contrast, all frequent AOS diagnoses presented low admission rates in tertiary hospitals. Conclusion The admission rates of frequent POS diagnoses in tertiary hospitals are high.Considering that these rates are the most important factors for the classification of disease severity, POS diseases seem to be underestimated in terms of severity. This may lead to a tendency for tertiary hospitals to intentionally reduce the admission of children with POS diseases. As a result, these children may not receive appropriate professional care. Therefore, for the disease severity, POS diseases should be classified differently from general AOS diseases by using different criteria reflecting the patient's age.

The claustrum, a brain nucleus located between the cortex and the striatum, has recently been highlighted in drug-related reward processing. Methyl CpG-binding protein-2 (MeCP2) is a transcriptional regulator that represses or activates the expression of the target gene and has been known to have an important role in the regulation of drug addiction in the dopaminergic reward system. The claustrum is an important region for regulating reward processing where most neurons receive dopamine input; additionally, in this region, MeCP2 is also abundantly expressed. Therefore, here, we hypothesized that MeCP2 would be involved in drug addiction control in the Claustrum as well and investigated how claustral MeCP2 regulates drug addiction. To better understand the function of human claustral MeCP2, we established a non-human primate model of methamphetamine (METH) - induced conditioned place preference (CPP). After a habituation of two days and conditioning of ten days, the CPP test was conducted for three days. Interestingly, we confirmed that virus-mediated overexpression of MECP2 in the claustrum showed a significant reduction of METH-induced CPP in the three consecutive days during the testing period. Moreover, they showed a decrease in visit scores (frequency for visit) for the METH-paired room compared to the control group although the scores were statistically marginal. Taken together, we suggest that the claustrum is an important brain region associated with drug addiction, in which MeCP2 may function as a mediator in regulating the response to addictive drugs.

Background: Ogden type IV tibial tuberosity fractures, defined as a type of fracture with posterior–inferior metaphyseal extension (Salter-Harris type II variant), are uncommon but challenging pediatric fractures. The purpose of this study was to investigate the clinical and radiological presentation and associated surgical outcomes. Methods: Ten previously healthy patients who had been surgically treated at the authors’ institution between 2015 and 2018 with at least 2 years of postoperative follow-up were included. Demographic, clinical, and radiological characteristics and treatment/ follow-up data were investigated. Results: All included patients were male. All injuries resulted from jump-landings. Unacceptable remaining angular deformity after closed reduction, particularly increased posterior tibial slope angle, was the leading cause of surgery. All preoperative magnetic resonance images (MRIs) showed entrapped periosteum on the anteromedial side of the proximal tibial physis. Surgical removal of the entrapped periosteum achieved successful reduction. Metaphyseal fracture angles between the fracture plane of the metaphyseal beak and the posterior tibial condyle on the axial image of MRI were relatively constant, with an average of 24.3° ± 6.0°. Mean bone age at the time of trauma was older than mean chronological age (16.4 ± 1.0 years vs. 14.6 ± 1.1 years, respectively; p = 0.005).All patients reached skeletal maturity within 2 postoperative years, with little posttraumatic residual height growth (mean, 1.6 ± 0.7 cm from injury to skeletal maturity). At final follow-up, no patients showed significant angular deformity, tibial length discrepancy, or functional deficit. Conclusions In healthy adolescents, Ogden type IV tibial tuberosity fractures typically occur by jump-landing injuries, when they have little residual growth remaining. Therefore, accurate fracture reduction was required because of limited remodeling potential.Patients with unacceptable reduction should be investigated for entrapped periosteum on the anteromedial side of the physis because it was the primary obstacle in achieving adequate reduction.