Estimation of Nationwide Vaccination Coverage and Comparison of Interview and Telephone Survey Methodology for Estimating Vaccination Status

This study compared interview and telephone surveys to select the better method for regularly estimating nationwide vaccination coverage rates in Korea. Interview surveys using multi-stage cluster sampling and telephone surveys using stratified random sampling were conducted. Nationwide coverage rates were estimated in subjects with vaccination cards in the interview survey. The interview survey relative to the telephone survey showed a higher response rate, lower missing rate, higher validity and a less difference in vaccination coverage rates between card owners and non-owners. Primary vaccination coverage rate was greater than 90% except for the fourth dose of DTaP (diphtheria/tetanus/pertussis), the third dose of polio, and the third dose of Japanese B encephalitis (JBE). The DTaP4: Polio3: MMR1 fully vaccination rate was 62.0% and BCG1:HepB3:DTaP4:Polio3:MMR1 was 59.5%. For age-appropriate vaccination, the coverage rate was 50%-80%. We concluded that the interview survey was better than the telephone survey. These results can be applied to countries with incomplete registry and decreasing rates of landline telephone coverage due to increased cell phone usage and countries. Among mandatory vaccines, efforts to increase vaccination rate for the fourth dose of DTaP, the third dose of polio, JBE and regular vaccinations at recommended periods should be conducted in Korea.

Investigation on the Frequency and Severity of Common Adverse Reactions of Japanese Encephalitis Vaccines / 소아감염

PURPOSE: To evaluate the number and severity of adverse reactions after Japanese Encephalitis (JE) vaccination in children using different vaccines (inactivated vaccine or live attenuated vaccine) and to determine the ability and safety of the vaccines to provide effective immunization for JE. METHODS: From August 2006 to February 2007, we conducted a prospective cohort study of the adverse reactions associated with JE immunization in Korea. We investigated common adverse reactions during the 4 days following immunization using telephone collaborations with four public health centers and nine pediatric clinics. RESULTS: The mean age of children receiving the inactivated vaccines and live attenuated vaccines, respectively, were 1.4 y (range: 1 to 8.5) and 1.7 y (range: 1 to 8.3). The number of children that received the inactivated vaccines was 425 (64.6%). A total of 233 (35.4%) received the live attenuated vaccines. Fourteen children (3.3%) had more than one localized adverse event with the inactivated vaccine, and six (2.6%) had more than one event with the live attenuated vaccine (P=0.607). Systemic adverse reactions occurred in 5.2% vs. 8.2%, respectively, of these groups (P=0.131). Fever was more common in the live attenuated vaccine group than in the inactivated vaccine group on the day of vaccination (P=0.026). CONCLUSIONS: The rate of adverse events in our study was even lower than that previously reported. No significant difference in outcomes between inactivated vaccine and live attenuated vaccine was found in JE-immunized children. Fever was more common in the live attenuated vaccine group than in the inactivated vaccine group on the day of vaccination.

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

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.

Assessment about the measles elimination from cases and outbreaks, 2002-2007: Assessment about the measles elimination / 소아과

PURPOSE: We assessed about the measles elimination in Korea according to analyzing national data on measles cases for 2002-2007. METHODS: We estimated the effective reproduction number according to the proportion of imported cases and outbreak size. RESULTS: Eleven cases, thirteen cases, six cases, six cases, 25 cases (60.0% were linked to 1 outbreak of 15 cases), and 180 cases (55.6% were linked 11 outbreaks of 2, 2, 2, 3, 3, 3, 5, 9, 9, 12, 50 cases) were reported in 2002, 2003, 2004, 2005, 2006 and 2007, respectively. In 2002-2007, R is 0.95 by imported case and 0.43 by outbreak sizes. In 2007, multiple chains of transmission occurred in hospital. Most of cases were below 4 ages and unvaccinated. We didn't find most of the infection source. CONCLUSION: We should prevent outbreak of susceptibility pocket like nosocomial infection, conduct reliable routine surveillance and epidemiological investigation to solve a problem of the measles elimination.

Epidemiological Investigation of a Measles Outbreak in a Preschool in Incheon, Korea, 2006 / 예방의학회지

OBJECTIVES: This study describes a plan that was designed to prevent a measles outbreak that showed a changed outbreak pattern. This study is based on the epidemiological investigation of a measles outbreak in a preschool in Incheon, Korea, 2006. METHODS: The subjects were 152 students at a preschool where a measles outbreak occurred. A questionnaire survey was conducted and serological testing for measlesspecific IgM was preformed. RESULTS: Of the fifteen confirmed, identified cases, eleven patients had been vaccinated with one dose, one patient had received two doses and three patients were unvaccinated. The three unvaccinated cases consisted of one 5-year-old child, one 3-year-old child and one 16-month-old infant. For the cases with one dose of the vaccination, there were 11 cases, which consisted of six 5-year-old children, two 4-year-old children, two 3-year-old children and one 2-year-old child. The case with two doses of the vaccination was one 4-year-old child. The attack rate of measles was 100% in the 0-dose group, 11.2% in the 1-dose group and 2.0% in the 2-dose group. The vaccine's efficacy was 88.8% in the 1-dose group and 98.0% in the 2-dose group. The vaccine effectiveness for the 2-dose group was higher than that of the 1-dose group. CONCLUSIONS: High coverage with a 2-dose vaccination should be maintained, and the vaccination should be given at the suitable time to prevent a measles outbreak with a changed outbreak pattern.

Expansion Project for National Immunization Program Coverage

Vaccination service is provided by public health centers and private hospitals in Korea. The central government (Korea Center for Disease Control and Prevention, KCDC) and local governments support whole public health centers financially including vaccination cost. However, people who get vaccinated at private clinics are not included as beneficiaries, so that they have to cover the expenses by themselves. Under this situation, the immunization registry rate at private clinics is much lower than that of the public sectors, so it is difficult to manage the vaccination history of each person. Through the 2005~2006 year demonstration projects, the government could confirm the necessities of coverage expansion for the National Immunization Program. In addition, the "Communicable Disease Control Law" and its implementing ordinances have been amended in 2006. In 2007, the government is trying to comply with the budget and to prepare a Notification about vaccination charge and the vaccination cost repayment process for the project.

Survey on the Epidemiological Characteristics of Measles Incidence between 1980 and 1999 Year in Korea / 감염

BACKGROUND: This study reports the incidences of measles in Koea and the epidemiologic characteristics for the incidence reported for the period 1980~1999. It provides the epidemeologic adta for measles before implementing the catch-up campaign in 2001. METHODS: We obtained information for the survey from the data for the incidence reported from health centers. Incidences per 100,000 population were calculated for the 1963~1999. And the following variables were studied: seasonal or regional distribution for the 1980~1999. RESULTS: The incidence rate of measles declined after the systemic immunization in 1990, the outbreak of measles occurred periodically and incidences per 100,000 population increased from 8.4 cases in 1990 to 17.7 in 1994. In 1990 and 1994, measles cases centered around the 5~6th month. On the other hand, in non-epidemic year measles cases were scattered around the year. The incidence rates of measles by the province were greatly defferent whenever the outbreak of measles occurred. CONCLUSION: In 1990s, the outbreak of measles occurred periodically at the interval of 4 years until 1994. The seasonal distribution may be caused by Iimitation of transmission due to the increased measles immunity in outbreak region. Our results showed that the measles outbreak did not occur in the specific province, but it occurred nationwide whenever measles outbreak occurred, even though the incidence rates of the provinces were different.

Epidemiological Characteristics of Measles Outbreakin 2000~2001, Korea / 감염

BACKGROUND: In 2000~2001 there was a nationwide outbreak of measles in the Republic of Korea. Since supplementary vaccination program was implemented in 2001, the control strategy of this measles outbreak has been stepped up from the control phase to the elimination phase. We here present the result of survey for the epidemiologic characteristics of the nationwide outbreak of measles in 2000~2001. METHODS: Using the data based on the sheet of epidemiologic investigation, incidences rates per 100,000 population and distributions of cases with vaccination history were investigated by the age. The seasonal or regional distribution were also studied with the onset days of cases. RESULTS: In 2000~2001, a measles outbreak occurred with 52,897 reported cases. The incidence rate per 100,000 population of measles was 111.9 cases and that of geopolitical unit (province) was high nationwide, 35.9~386.3 cases. The incidence rates were very high in less than 12 months and 10 years of age, 954.4 and 714.9, respectively. The 1st vaccination rate of measles/mumps/rubella (MMR) in 1~3 years old was 26.3~77.1%, and especially, that of 1 year old showed very low coverage, 26.3%. However, there was no special propensity in the 1st vaccine coverage in the age of 7~15 years, which had 87.7~91.4%. On the other hand, the 2nd MMR vaccination rate of the cases was very low, 17.7% at the age of 7~10 years. From the 21st May, 2001 a mass catch-up campaign with measles/rubella (MR) vaccine was launched, resulting in prominent reduction in the incidence of measles case. CONCLUSION: This survey showed that the measles outbreak in 2000~2001 had a high incidence nationwide from October 2000 to April 2001 and in less than 12 month and 10 years of age. Our results also showed that no routine immunization made the age group under 1 year vulnerable to measles infection. In cases of school-age group after 7 years of age, some cases with vaccination history were also infected. The characteristics of recent outbreaks indicates the need for the introduction of a specific vaccination programme at that age group. This survey was helpful to establish the effective vaccination strategy and it would be used as reference data on survey continuously for the epidemiologic characteristics of measles case for elimination of indigenous measles transmission in Republic of Korea.

Epidemiologic Investigation on an Outbreak of Cholera in Gyeongsangbuk-do, Korea, 2001 / 예방의학회지

OBJECTIVES: This study was carried out to investigate the cause, magnitude and transmission route of the cholera outbreak in 2001. METHODS: The study population were those persons who ingested foods at the restaurant, were confirmed as cholera patients, had symptoms of diarrhea and served as workers at the restaurant. A questionnaire survey and microbiological examinations on the microbes isolated from rectal swabs were conducted. Of the cases, 316 food histories were surveyed by an analysis of the restaurant menu. RESUJLTS: There were 139 confirmed cases of cholera reported in Korea in 2001. Of these, 104 were related to the restaurant. By region, Gyeongsangbuk-do had the highest incidence with 91 cases. Of these 91 cases, 74 had ingested foods at the restaurant, 2 were employees and 3 were secondary infection cases within the families. The results of the odds ratio analysis of the 316 persons having ingested foods at the restaurant were as follows: sandwiches 5.07 (95% CI, 1.85-14.59), soybean curd 2.45 (95% CI, 1.09-5.56), noodles 2.34 (95% CI, 1.24-4.42), steamed squid 2.01 (95% CI, 1.17-3.47) and vinegared rice 1.82 (95% CI, 1.08-3.09). It was certain the restaurant in question was the cause of the 2001 outbreak. CONCLUSIONS: We suspected that more than one restaurant employee contaminated foods served at the restaurant. In addition, eating raw fishes purchased at the Pohang Fisheries infected the employees of the restaurant. There is a possibility that these raw fishes were themselves contaminated by cholera bacilli in the sea.

Epidemiologic Investigation on an Outbreak of Cholera in Gyeongsangbuk-do, Korea, 2001 / 예방의학회지

OBJECTIVES: This study was carried out to investigate the cause, magnitude and transmission route of the cholera outbreak in 2001. METHODS: The study population were those persons who ingested foods at the restaurant, were confirmed as cholera patients, had symptoms of diarrhea and served as workers at the restaurant. A questionnaire survey and microbiological examinations on the microbes isolated from rectal swabs were conducted. Of the cases, 316 food histories were surveyed by an analysis of the restaurant menu. RESUJLTS: There were 139 confirmed cases of cholera reported in Korea in 2001. Of these, 104 were related to the restaurant. By region, Gyeongsangbuk-do had the highest incidence with 91 cases. Of these 91 cases, 74 had ingested foods at the restaurant, 2 were employees and 3 were secondary infection cases within the families. The results of the odds ratio analysis of the 316 persons having ingested foods at the restaurant were as follows: sandwiches 5.07 (95% CI, 1.85-14.59), soybean curd 2.45 (95% CI, 1.09-5.56), noodles 2.34 (95% CI, 1.24-4.42), steamed squid 2.01 (95% CI, 1.17-3.47) and vinegared rice 1.82 (95% CI, 1.08-3.09). It was certain the restaurant in question was the cause of the 2001 outbreak. CONCLUSIONS: We suspected that more than one restaurant employee contaminated foods served at the restaurant. In addition, eating raw fishes purchased at the Pohang Fisheries infected the employees of the restaurant. There is a possibility that these raw fishes were themselves contaminated by cholera bacilli in the sea.

Seroepidemiology of Mumps IgG Antibody on Primary School Children in Kyonggi Province, 1996 and 1999 / 감염

BACKGROUND: Although massive use of live attenuated mumps virus vaccines successfully reduced the incidence of mumps virus infection worldwide, mumps outbreaks have not been completely eliminated, even in vaccinated populations. In recent years, the incidence of mumps has been remarkably increased in Korea. This study was designed to evaluate the recent seroprevalence rate of mumps IgG among children in Kyonggi province at 1996 and 1999. METHODS: Study population included students from 8 elementary schools in Kyonggi province. Serum samples were collected twice at 1996 and 1999 and tested for mumps-specific antibody by enzyme-linked immunosorbent assay (ELISA). We also conducted a questionnaire survey on the parents and collected the records including history of vaccination and mumps infection. RESULTS: The seropositive rates against mumps were 89.47% and 89.74% at 1996 and 1999, respectively, and they were not significantly different when compared to age, sex, and region. Although the first vaccination rates were 92.17% and 92.25% at 1996 and 1999, respectively, the second vaccination rates were only 37.89% and 38.03% at 1996 and 1999, respectively. Infection rate showed no significant difference between vaccinated groups and nonvaccinated groups. Seropositive rate of infected group was higher than that of noninfected group but it was not significantly different between the vaccinated and the nonvaccinated. CONCLUSIONS: This study showed the seropositive rate and vaccination against mumps in children. There were no significant relationships between vaccination and infection. Therefore, it seems likely that the vaccination is not fully protective against mumps infection. This study will be helpful for the establishment of guideline for prevention and treatment of mumps in Korea.

The Altered Pattern of CD28 Expression on T Cell Subsets in HIV-Infected Koreans / 대한면역학회지

The CD8(+)CD28(+) T cells have known to mediate major histocompatibility complex class I-restricted cytolysis and to secret an HIV-1 inhibitory factor. As HIV infection lead to dramatic changes within the cellular immune system, the cellular cytotoxicities decrease in the duration of the HIV infection. To determine the importance of the cellular cytotoxicities in long-term nonprogression, we tried to compare CD28 expression on total T, CD4(+) T, and CD8(+) T cells as one of methods for cellular cytotoxicity measurements between long-term nonprogressor and normal person or between long-term nonprogressor and rapid progressor. The median percentages and counts of CD4(+) T cells of the norrnal, the long-term nonprogressor, and the rapid progressor groups were 39.9 and 0.96 * 10(9) cells/L, 24.6 and 0.58 * 10(9) cells/L, 9.9 and 0.15 * 10 cells/L, respectively. As a result of comparison of the cells having CD28 surface molecules on CD8(+) T cells in the long-term nonprogressor and the rapid progressor group, they showed over 5 times lower than that in the normal group. Especially, the long-term nonprogressor regarded to the healthy HIV-infected patient showed much lower CD28 expression on total T, CD4(+) T, and CD8(+) T cells than those of the normal person. The proportions of CD4'CD28 T and CD3CD28 T cell subsets showed the significant difference between the LTNP and the RP group. In conclusion, although HIV-infected patients were LTNPs having the steady CD4(+) T cell counts and no clinical symptoms, we suggested that HIV led to abnormality within the lymphocyte subsets such as the altered expression of CD28 molecules on various T cell subsets and this result would cause deficiency of host immune function and failure of control of HIV replication by anergy in T cell subsets.

Study on Relationship between Hypertension and Dietary intake in a Rural Adult Population / 예방의학회지

To determine the relationship between hypertension and nutrient intake cross-sectional study were performed in a rural area. Adult resident over 30-year-old age were measured blood pressure and body mass index(BMI), and interviewed about food intake for the previous 24 hours. 250 men and 297 women participated the survey. Significant correlation was shown in men between mean systolic blood pressure and protein density. Significant correlation with mean diastolic blood pressure was shown on protein density, protein energy(%), calcium density and energy-adjusted protein in men. We analysed risk factor for hypertension adjust the effect of age, BMI, sex and family history by multiple logistic regression. Protein density(odds ratio=3.18), fat density(odds ratio=1.94) and energy-adjusted protein(odds ratio=1.01) intake were positively associated with hypertension but sodium density(odds ratio=0.73) was shown to have inverse relationship.