Chang Hwi Kim

Epidemiological features of Kawasaki disease in Korea, 2006–2008

Background:  The aim of this study was to estimate the incidence and describe the epidemiological characteristics of Kawasaki disease among children in Korea.

Kawasaki disease in Korea, 2003-2005.

Purpose: The aim of this study was to investigate the incidence rate and epidemiologic patterns of Kawasaki disease in Korea for the 3-year-period, 2003–2005. Methods: The questionnaire for an epidemiologic survey on Kawasaki disease was distributed to all 102 Korean hospitals that conduct pediatric residency programs, and obtained data were analyzed upon receipt. Results: The 9662 patients of Kawasaki disease from 85 hospitals that responded (response rate, 83.3%) consisted of 5877 males and 3785 females (male:female ratio, 1.55:1). The incidence rate per 100,000 children <5-year-old was 104.2 in 2003, 106.4 in 2004, and 104.6 in 2005 (average rate, 105.0). Their mean age of onset was 33.3 months, and the proportions of sibling cases and recurrent cases were 0.29% and 2.0%, respectively. Coronary arterial abnormalities were detected at follow-up by echocardiogram in 18.8% of all such cases including dilatations of 18.0% and aneurysms of 2.5%. Conclusion: The average annual rate of incidence, 105.0/100,000 in children <5-year-old is the second highest reported rate in the world.

The Causative Organisms of Bacterial Meningitis in Korean Children in 1996-2005

Bacterial meningitis remains a serious cause of morbidity and mortality in childhood, despite the availability of effective vaccines against Haemophilus influenzae type b (Hib) or Streptococcus pneumoniae. The purpose of this study was to analyze data on bacterial meningitis cases in Korea from 1996 through 2005. The information of all hospitalized bacteria-proven meningitis cases was obtained from 17 university hospitals nationwide. A total of 402 cases were identified. Of these, 125 (29.9%) cases were neonates. Streptococcus agalactiae was the most common bacteria responsible for 99 (24.6%) of all cases regardless of age, followed by S. pneumoniae for 91 (22.6%) and H. influenzae for 67 (16.7%) patients. The common etiology beyond the neonatal period was S. pneumoniae for 91 (33.0%) followed by H. influenzae for 63 (22.8%) patients. The overall case fatality rate was 9.4%, which was similar with that in 1986-1995. In conclusion, S. agalactiae, S. pneumoniae and H. influenzae were important etiologic agents of bacterial meningitis in children in the last 10 yrs. It is required to establish the preventive strategy of the three bacteria. The nationwide epidemiologic study should be continued to evaluate immunization strategy and efficacy.

Prevalence of primary immunodeficiency in Korea

This study represents the first epidemiological study based on the national registry of primary immunodeficiencies (PID) in Korea. Patient data were collected from 23 major hospitals. A total of 152 patients with PID (under 19 yr of age), who were observed from 2001 to 2005, have been entered in this registry. The period prevalence of PID in Korea in 2005 is 11.25 per million children. The following frequencies were found: antibody deficiencies, 53.3% (n = 81), phagocytic disorders, 28.9% (n = 44); combined immunodeficiencies, 13.2% (n = 20); and T cell deficiencies, 4.6% (n = 7). Congenital agammaglobulinemia (n = 21) and selective IgA deficiency (n = 21) were the most frequently reported antibody deficiency. Other reported deficiencies were common variable immunodeficiencies (n = 16), X-linked agammaglobulinemia (n = 15), IgG subclass deficiency (n = 4). Phagocytic disorder was mostly chronic granulomatous disease. A small number of patients with Wiskott-Aldrich syndrome, hyper-IgE syndrome, and severe combined immunodeficiency were also registered. Overall, the most common first manifestation was pneumonia. This study provides data that permit a more accurate estimation PID patients in Korea.

Epidemiologic picture of Kawasaki disease in Korea, 2000–2002

Background : The aim of this study was to investigate the incidence rate and epidemiologic patterns of Kawasaki disease in Korea for a 3 year period during 2000 to 2002.

Response to primary and booster vaccination with 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine in Korean infants.

Background: This randomized single-blind study in Korea evaluated noninferiority of the 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) versus the 7-valent pneumococcal conjugate vaccine (7vCRM) when both were coadministered with H. influenzae type b (Hib) conjugate vaccine, as opposed to coadministration with diphtheria-tetanus-acellular pertussis-based combination vaccines in previous studies. Methods: Infants received 3 primary doses at 2, 4, and 6 months and a booster dose at 12 to 18 months of PHiD-CV (N = 374) or 7vCRM (N = 129), both coadministered with Hib vaccine. Immune responses were measured 1 month postdose 3 and postbooster using 22F-inhibition enzyme-linked immunosorbent assay and functional opsonophagocytic activity assay. Results: PHiD-CV-induced antibody responses against each of the vaccine pneumococcal serotypes and protein D. Noninferiority to 7vCRM was demonstrated for all 10 PHiD-CV serotypes in terms of percentages of subjects reaching an antibody concentration ≥0.2 &mgr;g/mL after primary vaccination. Postprimary and postbooster, percentages of subjects with antibody concentration ≥0.2 &mgr;g/mL or opsonophagocytic activity titer ≥8 were generally consistent between groups for each pneumococcal serotype common to both vaccines. The safety and reactogenicity profiles of PHiD-CV and 7vCRM were generally comparable after both primary and booster vaccination. Conclusions: In this Korean study, 3-dose PHiD-CV priming followed by a booster dose was immunogenic for all 10 vaccine pneumococcal serotypes and protein D. Noninferiority to 7vCRM in terms of enzyme-linked immunosorbent assay threshold responses postpriming was demonstrated. The safety and reactogenicity profiles of both vaccines when coadministered with Hib vaccine were generally comparable.

Current status and clinical presentations of invasive neonatal Group B streptococcal infections in Korea

Background:  Group B streptococcus (GBS) is the most common cause of invasive neonatal infections in developed countries. The incidence of early‐onset GBS disease in Korea is known to be much lower than that in other developed countries; however neonatal GBS disease has been frequently reported in recent years in Korea. This retrospective study sought to determine the current status and clinical presentation of neonatal GBS disease in Korea.

Immunogenicity and safety of a tetravalent measles-mumps-rubella-varicella vaccine: an open-labeled, randomized trial in healthy Korean children

Purpose This study (NCT00751348) evaluated the immunogenicity and safety of a combined measles-mumps-rubella-varicella (MMRV) vaccine compared to co-administration of measles-mumps-rubella and varicella (MMR+V) vaccines in Korean children during their second year of life. Materials and Methods Healthy children aged 11-24 months received one dose of MMRV or MMR+V. Antibody titers against measles, mumps and rubella were measured using enzyme-linked immunosorbent assay and against varicella using an immunofluorescence assay. Parents/guardians recorded adverse events in diary cards for up to 43 days post-vaccination. The primary objective was to demonstrate non-inferiority of MMRV to MMR+V for all antigens in terms of seroconversion rates (SCRs), defined as a group difference with a lower limit of the 95% confidence interval (CI)>-10%. Results Of 474 subjects enrolled, 458 (MMRV, 301; MMR+V, 157) were included in the according-to-protocol cohort. For measles (98.0% vs. 99.4%), rubella (99.7% vs. 100%) and varicella (98.9% vs. 100%) SCRs, the lower limits of the 95% CIs for group differences were greater than -10%; however, for mumps SCRs (88.8% vs. 94.2%), it was -10.40%. The primary objective of non-inferiority in mumps SCRs was therefore not met, although the observed group difference in a post-hoc analysis of anti-mumps antibodies using a plaque reduction neutralization assay was 0.39% with a 95% CI lower limit of -4.03%. Adverse events occurred at comparable frequencies for both groups, except for more frequent fever in MMRV recipients. Conclusion Based on the pre-specified non-inferiority criterion, SCRs of the MMRV vaccine were non-inferior to that elicited by MMR+V vaccines for all antigens except mumps.

Risk factors for acute hepatitis A infection in Korea in 2007 and 2009: a case-control study.

This study aimed to identify the risk factors associated with acute hepatitis A virus (HAV) infection in the Korean population. Participants were recruited from five referral hospitals across the country in 2007 and from 11 hospitals in 2009. Patients with positive anti-HAV IgM antibody tests became the case group, while patients treated for non-contagious diseases at the same hospitals were recruited as controls. A total of 222 and 548 case-control pairs were studied in the 2007 and 2009 surveys, respectively. Data from the surveys were analyzed jointly. In a multivariate analysis, sharing the household with HAV-infected family members (OR, 6.32; 95% CI, 1.4-29.6), contact with other HAV-infected individuals (OR, 4.73; 95% CI, 2.4-9.4), overseas travel in 2007 (OR, 19.93; 95% CI, 2.3-174.4), consumption of raw shellfish (OR, 2.51; 95% CI, 1.8-3.5), drinking bottled water (OR, 1.64; 95% CI, 1.3-8.4), and occupation that involve handling food (OR, 3.30; 95% CI, 1.3-8.4) increased the risk of HAV infection. Avoiding contact with HAV-infected individuals and avoiding raw foods eating could help minimize the risk of hepatitis A infection. Immunization must be beneficial to individuals who handle food ingredients occupationally or travel overseas to HAV-endemic areas.

Mumps Transmission Control Status and Inapparent Infection Rate among Middle and High School Students during the 2007-2008 Mumps Outbreak in Daegu.

OBJECTIVES This study was performed to investigate the mumps transmission control status and inapparent infection rate among middle and high school students in Daegu City during a mumps outbreak. METHODS Nine schools (two middle schools and seven high schools), which reported a number of mumps cases between 2007 and 2008 were selected for investigation. During March-May 2008, a standard questionnaire was distributed to gather information about case identification, instructed isolation measure, isolation status of mumps cases and related factors, and outdoor activities of non-isolated mumps case. Inapparent infection rate was estimated by serum mumps IgM and IgG antibodies status and self-reported mumps symptoms in three of the nine schools. RESULTS Among 2,560 respondents, more than half of students answered that they did not receive instructions in mumps transmission control measures during the outbreak. Among the 327 mumps cases identified by the questionnaire, 131 cases (40.1%) were considered as isolated and the isolation rates were significantly different among schools, grades, and gender. Of the non-isolated cases, 88.3% continued attending school. Inapparent mumps infection rates were between 56.3% and 70.2%. CONCLUSIONS Mumps transmission control was inadequate to control the mumps outbreak. Although high inapparent infection rate would mitigate the transmission control effect of case isolation, this measure is fundamental for infection control. The reasons of this inadequate status need to be explored to develop an effective intervention strategy.