Age-period-cohort analysis of hepatitis A incidence rates in Korea from 2002 to 2012 / 한국역학회지

OBJECTIVES: This study aimed to evaluate the epidemiology of hepatitis A in Korea from 2002 to 2012 using age-period-cohort analyses. METHODS: We used claims data from the Korean National Health Insurance Corporation for the entire population. Census data from 2010 were used as the standard population. The incidence of hepatitis A was assumed to have a Poisson distribution, and the models and effects were evaluated using the intrinsic estimator method, the likelihood ratio, and the Akaike information criterion. RESULTS: The incidence of hepatitis A gradually increased until 2007 (from 17.55 to 35.72 per 100,000 population) and peaked in 2009 (177.47 per 100,000 population). The highest incidence was observed among 27-29-year-old individuals when we omitted data from 2005 to 2007. From 2005 to 2007, the peak incidence was observed among 24-26-year-old individuals, followed by 27-29-year-olds. The best model fits were observed when the age-period-cohort variables were all considered at the same time for males, females, and the whole population. CONCLUSIONS: The incidence of hepatitis A exhibited significant age-period-cohort effects; its incidence peaked in 2009 and was especially high among Koreans 20-39 years of age. These epidemiological patterns may help predict when high incidence rates of hepatitis A may occur in developing countries during their socioeconomic development.

MMR Immunization Rate and Related Factors: Findings from Repeated Surveys (1996, 1999) on Elementary School Students in Kyonggi Province, Korea

PURPOSE: This study was carried out to obtain the immunization rate of MMR, and to know the related factors. METHODS: Subjects of the study were 3,364 students of 8 elementary schools of Kyonggi province. Surveys accompanied with questionnaires were conducted in 1996 and 1999, respectively. RESULTS: The salient features of the findings were as follows : The immunization rate for MMR turned out to increase as the age of students becomes younger and the 2nd MMR coverage rate in the 1999 survey was 30%. The MMR immunization rate had a strong positive correlation with parental education and income levels. The 2nd MMR immunization rate also had a strong positive correlation with the level of parental education. The vaccination record-keeping rate increased from 30% in 1996 to 41% in 1999. Especially, 52% of freshmen had a record in 1999. The record keeping rate had a strong positive correlation with parental education and income levels. Vaccination places for MMR were hospital or clinics in 60% and public health centers in 39%. CONCLUSION: The vaccination coverage rate for MMR was 85.5% in 1996 and 83.0% in 1999, respectively. The immunization rate however was not high enough to be able to protect against the MMR epidemy. In particular, we should pay more attention to vaccinating the children whose parents' education or income level is low. And we need to have a program that will enhance coverage for the 1st and the 2nd MMR among school children.

An Epidemiologic Investigation on Mumps Outbreak in Cheju-do, 1998 / 예방의학회지

OBJECTIVES: To describe the characteristics of a mumps epidemic in Cheju-do, 1998 and to identify the risk factors associated with mumps infection. METHODS: To estimate attack rate, previously collected data from the Nationally Notifiable Communicable Disease Reporting System and School Health Reporting System, temporarily administered by Division of Education, as well as additional surveillance data were used. In order to identify the clinical characteristics and risk factors associated with mumps, we conducted a questionnaire survey in 17 schools (9 elementary, 4 middle, and 4 high schools) among a population that included healthy students. RESULTS: From March 3 to August 31, 2,195 cases of mumps were identified, and patients under 20 years of age accounted for 2,162 cases (attack rate 13.2, 95% CI 12.6-13.7/1,000). The attack rate for the population under 20 years of age was the highest in Nam county (44.7/1,000), and in the 7-12 years old sub-group(>20.0/1,000). There was no sexual difference. 80.9% and 59.7% of patients presented periauricular and submandibular swelling respectively. Aseptic meningitis was a complication in 2.9% of cases, orchitis in 1.3%, epididymitis in 0.9% and oophoritis in 0.6% respectively. The overall MMR vaccination rate was 59.1% and it decreased in accordance with increasing age. In students aged 10 years old or below, household contact and MMR vaccination status was significantly associated with infection, and only among students with household contact, the risk of one dose MMR(OR=10.22, 95% CI 2.92-35.78) and non-vaccination (OR=11.62, 95% CI 1.96-68.96) was significantly greater when compared with that of two dose vaccination. Among students aged 11 years old or above, household contact history was significantly associated and MMR vaccination status was not associated. CONCLUSIONS: Low vaccination rate and vaccine failure were thought to predispose the population for this large outbreak. To prevent sustained mumps outbreaks, a second MMR vaccination should be encouraged and catch up vaccinations should be given to elderly children who remain susceptible.

Lipid Profiles and Related Factors in Adolescent / 예방의학회지

OBJECTIVES: To assess the prevalence rate of dyslipidemia and the level of related factors in adolescents groups in Seoul and Yangpyong area. METHODS: Design; School based survey during May-Jun 1996 in Seoul and Yangpyong county. Subject; 2,453 boys and girls, aged 13 to 19 years; 1,137 Seoul and 1,316 Yangpyong county. Main Outcome Measures; Prevalence rates of raised serum total cholesterol, triglycerides, LDL-cholesterol, decreased HDL-cholesterol, obesity, and levels of energy intake and expenditure RESULTS: Energy intake and fat intake of boys were higher than those of girls and they were higher in Seoul. Energy expenditure per day of boys was bigger than that of girls too. Prevalence rate of obesity was higher in boys of Seoul(15.2%) and girls in Yangpyong county(14.0%). Serum lipid profiles(total cholesterol, triglycerides, LDL-cholesterol) were higher among girls and all prevalence rates of dyslipidemia were higher in boys in Seoul and in girls in Yangpyong county. Especially, girls(29.1%) in Yangpyong had raised serum cholesterol level(> or =170 mg/dl). In contrast, boys in Seoul had higher level of decreased HDL-cholesterol(46.8%) compared to Yangpyong(23.6%). The relationships between serum lipid profiles and relative weights and sex are highly significant. And the relationship between triglycerides and energy intake is significant(p=0.038). But, the associations between serum lipid profiles and energy expenditure had borderline significances. CONCLUSIONS: Hypercholesterolemia rates in girls were higher. Obesity prevalence rate was highest in boys of Seoul. Relative weight and sex are significantly related to lipid profiles. Therefore, Korea is in need of preventive strategies for different obesity and gender groups.

The Effect of Parental Socioeconomic Status on the Nutrient Intake of Urban and Rural Adolescents / 대한지역사회영양학회지

This study was conducted to assess the nutrient intake patterns among urban and rural adolescents and to investigate the effects due to parent's socioeconomic status and other factors, such as mother's job, family type and regular exercise on that pattern. 2,455 middle and high school students living in Seoul and Yangpong, Kyounffi-Do participated in a self-administered questionnaire that was used to collect data. The one-day dietary intake was surveyed through a 24-hour recall method. The factors significantly different between urban and rural adolescents according to monthly income, parent's education level, mother's job, family type and exercise. Income, the parents' education level and regular exercise were associated with the patterns of nutrient intakes as a percent of the RDA. So, when adjusted for parental income, the father's and mother's education level and regular exercise, there were no signifcant differences within the patterns of nutritional intake between urban and rural adolescents. The results provided the information regarding the determinants of nutrient status among adolescents and were expected to be helpful for planning school health promotion programs.

A Seroepidemiologic Study on Rubella Antibody in Pregnant Women in Kyonggi Do / 예방의학회지

The vaccinations of susceptible children and postpubertal females are the major means to prevent congenital rubella syndrome(CRS). Another means for reducing the CRS is therapeutic abortion or fetal monitoring for women who are infected in the first four months of pregnancy. We couldnt estimate the incidence of CRS in Korea, because there was no surveillance system for rubella and CRS. Nationwide vaccination program for 15months infant had been started early 1980s. So, most women at childbearing age during study period were not received rubella vaccination. We set forth CRS management system for pregnant women in two rural county of Kyonggi province, Korea. In this system, the presence of rubella IgG and IgM antibodies for early pregnant women were examined with MEIA(Microparticle Enzyme Immunoassay) method by IMx automated analyzer Abbott. The infected pregnant women followed up in order to confirm their children CRS. This study was carried out from Mar.1993 to Jun.1994, and pregnant women examined were 874 persons. The results were summarized as follows. The overall positive rate of rubella IgG antibody was 94.5%(826/874). The positive rate was significantly increase as the age increased, and reached 100% in pregnant women who were over 35 years old. This results suggest that a meaningful number of women are infected during childbearing years. The geometric mean titer of IgG of sero-positive subjects was significantly declined as the age increased. On the question about history of URI symptoms and rash in pregnancy, 20.7% of respondents checked on URI symptoms with rash, 13.5% only URI symptoms without rash, and 65.8% no symptoms. However there was no demonstrable association between the rubella like infection history in pregnancy and the rubella IgG and IgM antibody status. Rubella infection rate in pregnant women was 0.9%(95% CI 0.4-1.8%). Two of these 8 infected pregnancies were terminated by therapeutic abortion. One of them was not followed. Five babies had no gross anomalies at birth. In Dec.1996, three of five babies were normal appeared infants. Two of them were not followed. Throughout this study results, we confirmed the need of CRS management system for pregnant women, in Korea.

Toxoplasma antibody titers by ELISA and indirect latex agglutination test in pregnant women

The seroepidemiologic studies on anti-Toxoplasma antibody titers were carried out using ELISA and indirect latex agglutination test. Among 899 sera prepared from pregnant women, 39 cases (4.3%) revealed positive reaction and 218 sera from middle school students showed 4 positive reaction (1.8%) by ELISA. By LAT(newly established by National Veterinary Research Institute, Korea), the sera of 7 pregnant women (0.8%) showed positive reaction. When 80 sera showing +S1:8 by LAT were used for comparing the results obtained from LAT and Toxotest-MT (Eiken Chemical Co., Japan), 7 cases and 8 sera were positive, respectively. All of 11 sera of proven toxoplasmosis patients showed positive reaction in both tests. Overall proportion of agreement between LAT kit and Toxotest-MT was 0.94( -index= 0.632, p<0.01), and LAT was considered to be useful for the screening of toxoplasmosis.

Analysis on the Relationships among the Total Cholesterol, Fasting Blood Sugar, Hypertension and Ischemic heart disease on EKG Findings / 예방의학회지

Since the 1960's, Korea has achieved rapid economic growth, longer life expectancy, accelerated urbanization and a westernization of diet. Cardiovascular disease has become the leading cause of death; however the prevalence of ischemic heart disease(IHD) remains low. A cross-sectional multiphasic screening service for 18,426 persons aged 30 64 years in a Medical Aid Program in Kyonggi-do Province was conducted from 1991 to 1993. Total cholesterol(TC), Fasting blood glucose(FBG), blood pressure(BP), and electrocardiographic(EKG) data were collected. The result as follows; 1. On the EKG findings, the age-adjusted prevalence of myocardial ischemia and myocardial infarction was 1.45% in men and 2.06% in women. 2. The mean blood pressure was 122.9/78.8mmHg. The age-adjusted prevalence of hypertension was 11.05% in men and 9.02% in women. The prevalence of hypertension showed increasing tendency according to age increase. In all age group, the prevalence of hypertension was higher in men than women. 3. The mean total cholesterol level was 184.4mg/dl in men and 189.2mg/dl in women. The age-adjusted prevalence of hypercholesterolemia was 4.88% in men and 5.67% in women. The total cholesterol level showed increasing tendency according to age increase, except 55 64 age group in men. 4. The prevalence of hyperglycemia is 5.8%. The age-adjusted prevalence of hyperglycemia is 6.72% in men and 4.50% in women. The prevalence of hyperglycemia showed increasing tendency according to age increase. 5. On the EKG findings, the prevalence of myocardial ischemia and myocardial infarction was higher in hypertension than normal, in all age group of men and women less than 40 years-old. Only in women more than 40 years-old, the prevalence of myocardial ischemia and myocardial infarction was higher in hypercholesterolemia and hyperglycemia. Nevertheless there is not statistical association between ischemic heart disease and previous risk factors in other age group, the prevalence of myocardial ischemia and myocardial infarction was higher in hypertension, hypercholesterolemia and hyperglycemia than normal. The result of this study suggest that relationships between major risk factor of ischemic heart disease and ischemic heart disease is similar to existing theory.