• Journal of Preventive Medicine and Public Health
• /
• v.30 no.1 s.56
• /
• pp.17-29
• /
• 1997

To estimate the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection and to determine associated risk factors, a population-based seroepidemiologic study was carried out. In 1993, a health examination survey of the population was carried out in rural area known to have a high incidence of liver cancer. The study population were those who volunteered to participate in a health survey over 10 years of age. Examinees were interviewed by specially trained staffs. Sera from 1,033 study subjects were tested for hepatitis B surface antigen (HBsAg) by .everse passive hemagglutinin (RPHA) estimation and for hepatitis C virus antibody (anti-HCV) by 2nd generation passive hemagglutinin (PHA) estimation. The age and sex standardized prevalence of HBsAg was 6.3% which was similar to national average, but that of anti-HCV was 5.1% which was 4 to 5 times higher than that of blood donors or other health examinees in Korea. In a multivariate analysis, transfusion history, surgical operative history, and acupuncture history were not associated with HBsAg positivity. In contrast, acupuncture history (adjusted odds ratio[OR]=2.2 : 95% Confidence interval[CI] 1.0-4.7) and surgical operative history(adjusted OR=2.0 : 95% CI 1.0-4.1) were associated with anti-HCV positivity. The present study suggest that there is an highly endemic area of HCV infection in Korea and probably this endemicity is associated with a parenteral source of HCV infection other than blood transfusion.

• Journal of Preventive Medicine and Public Health
• /
• v.40 no.4
• /
• pp.285-290
• /
• 2007

Objectives : Cases of human brucellosis in Korea have recently increased due to the increasing incidence of bovine brucellosis. The authors conducted this study to elucidate the status of brucellosis through seroepidemiologic study. Methods : We selected our study population from a high risk group. We conducted a questionnaire survey and obtained blood samples to determine the seroprevalence of brucellosis antibodies for 10 days in February, 2005. The titers of brucellosis were measured by the combination of standard tube agglutination test (STA) and enzyme-linked immunosorbent assay (ELISA) test. Results : Our study subjects comprised 1,075 cases: 971 livestock workers, 51 veterinarians, and 53 artificial inseminators. In the STA test, 27 cases (2.5%) had titers of greater than or equal to 1:20. Of 1,068 cases (7 cases were excluded due to previous brucellosis), 7 cases of brucellosis were diagnosed with titers of 1:160, giving a seroprevalence of brucellosis of 0.66%. The seroprevalence in the male group was 0.95%, and that of livestock workers, veterinarians, and artificial inseminators was 0.52%, 4.17%, and 0.00%, respectively. The Spearman's correlation coefficient between the positive rate of bovine brucellosis per capita and household and human brucellosis was 0.806 and 0.744, respectively. The concordance rate between the Korea National Institute of Health and the Gyeongsangbuk-do Institute of Health and Environment by the STA and ELISA tests was 94.7% and 100.0%, respectively. Conclusions : The study results indicated in higher seroprevalence rate among veterinarians than among livestock workers and artificial inseminators. Because veterinarians may be exposed to this high risk, effective working guidelines for veterinarians to guard against brucellosis must be developed. Moreover, more extensive epidemiologic research for laboratory workers and meat handlers is needed.

• Journal of Preventive Medicine and Public Health
• /
• v.54 no.5
• /
• pp.370-375
• /
• 2021

Objectives: The number of cases of hepatitis A virus (HAV) infections has sharply increased in Korea, especially among young adults. In this study, an HAV outbreak in a facility for disabled people was investigated, and we found epidemiological differences both between 2 different generations and between generally abled and disabled groups. Methods: We analyzed the incubation period and attack rate of an HAV outbreak and investigated the prevalence of HAV antibodies among the staff and residents of a facility for the disabled. We performed a retrospective cohort study during the HAV outbreak, which lasted from February 8 to 25, 2019, including examinations of HAV antibody tests and post-exposure HAV vaccination for the staff or residents of the facility. Results: There were 9 confirmed cases in 2 staff members and 7 residents. Among 53 people (30 staff and 23 residents), except for the 9 confirmed cases and 1 staff member with a known history of HAV infection, HAV seroprevalence was seen in 16.7% of the staff under 40 years of age and 95.2% of those over 40 years of age, while the corresponding rates in the residents were 0.0% and 58.8%, respectively. Conclusions: This result implies that it is necessary to prioritize HAV vaccination for vulnerable groups and workers of residential care facilities.

• Parasites, Hosts and Diseases
• /
• v.37 no.2
• /
• pp.109-115
• /
• 1999

The present study observed the variation of antigenicity of Pneumocystis carinii and serum IgG antibody reastion to the antigens from different localtities in Korea. Antigens of rat P,carinii and sera of inhabitants were collected at Chunchon, Chungju, Kwangju and Seoul during 1995-1996. Enzyme-Linked Immunosorbent Assay and immunoblot were used for immune reaction. Absorbance of 1,294 human sera ranged between 0.01and 0.93. Sera from Chunchon showed higher absorbances than those from other areas. Immunoblotting revealed IgG antibody reactions to 116,100, and 45-55 kDa antigenic bands of rat P.carinii, but the frequencies of positive reaction to individual bands were variable by localities. Total 62.6% reacted to 100kDa band and 32.0% to 45-55 kDa bands. For the reaction to 116kda, the reaction rate was 60.0% of the sera showed the reaction to 116kda band while 37.7% reacted to 100kda, the reaction rate was 60.0% to 82.6% by localities. It is found that the reaction rates of the human sera to rat P.carinii antigen are variable according to the localities. Also, the high molecular antigen of 116kDa of rat P.carinii is the most frequent antigenic band reaction to human sera.

• The Journal of the Korean Society for Microbiology
• /
• v.17 no.1
• /
• pp.7-14
• /
• 1982

A model of induction of neoplasia by viruses has develpoed from experimental studies in animals and in cultured cells and oncogenic transformation of cells is the result of integration of viral genetic information into the cellular DNA. The evidence for these associations was derived primarily from seroepidemiologic investigation. However, data indicating that the relation between HSV-2 and cervical cancer fits the model derived from experimental animal studies are not yet sufficient to draw conclusion with regard to the etiologic role the virus in the development of the neoplasms. In other hand, the K562 tumor cell is highly susceptible target for natural killer cell lysis by the lymphocytes of human and murine periperal blood. The characteristics of this effector cell type has been investigated. A study on natural killer cell mediated cytotoxicity(NKMC) against $^{51}Cr$-K562 as target cell was studed in HSV-2 infected ICR mouse. We have studied for susceptibility of HSV-2 against mouse embryo fibroblast(MEF) cells and NKMC from HSV-2 infected mouse. The results obtained that the mouse embryo fibroblast cells culture, the number and size of the cells were markedly increased and formed a monolayers relatively rapid, and become complete monolayer sheet around 72 hrs. Duration of cytopathic effect on MEF cells was rapid by serial passing of HSV-2. The morphology of the HSV-2 infected cells appear to be mainly round, ovium, spindle form and some of them was forming large giant cells. The NKMC was decrease in mouse with HSV-2 and comparison between effector/target cells ratio as 25:1 and 50:1 respectively, the NKMC was found to be more significantly decreased than normal control we have concluded that the natural killer cell activity of the viral infected mouse was shown as a suppressed during the HSV-2 infection, day 7th and 14th.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.13 no.2
• /
• pp.134-145
• /
• 2010

Purpose: The serologic diagnosis of rotaviral infections is not commonly used in clinical practice, but is used in seroepidemiologic studies. In this study, the usefulness of Escherichia coli-expressed recombinant VP6 proteins of group A rotavirus in the serodiagnosis of rotavirus infections by ELISA was evaluated. Methods: The recombinant VP6 proteins of group A rotavirus expressed in E. coli Rosetta II strain were purified and identified. One hundred sera from 22 children (4 healthy neonates, 13 healthy children, and 5 immunocompromised children) who had serial sera samples prior to and after rotavirus infections were provided by the Gyeongsang National University Hospital, a member of the National Biobank of Korea. IgG, IgA, and IgM antibodies against rVP6 were analyzed by ELISA in all of the patients and Western blot analysis in 4 neonates. Results: ELISA tests using rVP6 proteins of group A rotavirus as antigen revealed that IgG, IgA, and IgM antibodies increased after rotaviral infections in most neonates and healthy children. IgG antibodies also increased after rotaviral infections in most immunocompromised children without an adequate increase in IgM or IgA antibodies. Western blot analysis in four neonates revealed very early IgM antibody responses, even in the sera with low optical densities in ELISA tests. Conclusion: Our study showed that ELISA using rVP6 as an antigen is a valid diagnostic tool for seroepidemiologic studies of rotavirus infections and Western blot analysis is a sensitive test in detecting IgG, IgA, and and IgM antibodies in patients with rotavirus infections.

• Journal of Preventive Medicine and Public Health
• /
• v.30 no.2 s.57
• /
• pp.279-292
• /
• 1997

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 could not 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 $Abbott^(R)$. The infected pregnant women followed up in order to confirm their childrens CRS. This study was carried out from Mu. 1993 to Jun. 1994, and pregnant women examined were 874 persons. The results were summarized as follows. The overall positive .ate 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 .ash, 13.5% only URI symptoms without .ash, 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 .ate 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.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.15 no.2
• /
• pp.85-90
• /
• 2012

Purpose: Commercial enzyme-linked immunosorbent assay (ELISA) kits have been considered less reliable for children than for adults. The aim of this study was to compare four ELISA kits and in-house immunoblotting based on the analysis of anti-H. pylori-IgG antibody reactivity. Methods: A total of 399 serum samples were collected at the GNU Hospital during 1998-1999. All sera were tested using ELISA and immunoblotting. Statistically significant differences were determined by the $x^2$ test. Results: The overall seropositivity rates using GAP IgG, Genedia IgG, HM-CAP, Pyloriset EIA-G, and immunoblotting were 13.0%, 25.1%, 18.3%, 15.8%, and 62.9%, respectively. Immunoblotting showed a higher seropositivity rate than did all four ELISA kits in all age groups. Genedia IgG had the highest seropositivity among the ELISA kits. The seropositivity rate for children aged 13 to 18 months was lowest, and that of children aged 15 years was highest (90.0%). The seropositivity rate for children aged 7 months to 5 years was significantly lower than that for children aged 6 to 15 years among the four ELISA kits (p<0.0001) and immunoblotting (p=0.02). Conclusion: Immunoblotting is the most sensitive test for detection of anti-Helicobacter pylori IgG antibodies among the serological tests in this study. These results emphasize the need for standardization when commercial ELISA tests are used in different nations or in young age groups. Immunoblotting could be a suitable noninvasive assay for serodiagnosis and seroepidemiologic study of H. pylori infection in Korean children.

• Journal of Preventive Medicine and Public Health
• /
• v.21 no.1 s.23
• /
• pp.89-98
• /
• 1988

While there have been not a few reports on the seroepidemiological characteristics of hepatitis B virus (HBV) infection in Korea, most of them, however, have had several limitations; operational definition of HBV infection, validity of detection methods of HBV serologic markers, size of the study population, and confirmation of the vaccination history against HBV, etc. In order to avoid such limitations, authors randomly selected 1,495 healthy adults among the 217,511 insured (target population) of Korean Medical Insurance Corporation, living in seoul, and tested HBV serologic markers by RIA method and conducted direct interview to them. Although HBV serologic markers (HBsAg, anti-HBs and anti-HBc) of all the subjects were tested, 392(26.2%) of interview failure cases and 361 vaccinee were excluded from the actual population. Finally, the serologic markers tested of 742 nonvaccinee (study population) only were analysed for the seroepidemiologic observation of the natural infection of HBV. The seroepidemiological characteristics of HBV infection in Korea were as follows ; 1. Point prevalence of HBs antigenemia was 11.7(9.1{\sim}14.3)% in male, which was slightly higher than that of female, 9.5($3.7{\sim}15.3$)%. This level was one of the highest among those of Asian-Pacific countries. Decreasing tendency of HBsAg prevalence alter the age of 50 was observed, which seems to be due to selective attrition of HBV chronic carriers among the healthy adults and/or to the limited-lasting duration of the HBs antigenemia, in part. 2. Point prevalence of anti-HBc(78.8% in male,50.9% in female) was higher than that of anti-HBs(65.2% in male,46.6% in female), respectively. And both of them were higher in male than in female. Increasing tendency of the prevalence of both antibodies was observed by age, which seems to be largely due to recurrent infection in adults and to some cumulative effect, in part, of their relatively longer-lasting duration. 3. The level of HBV infection defined by positive for at least one of the 3 serologic markers of HBV by RIA method was 84.7($81.8{\sim}87.6$)% in male and 61.2($51.9{\sim}70.5$)% in female, which was also one of the highest among those of Asian-Pacific countries. The proportion of susceptible population to HBV infection among healthy adults was 15.3% in male and 38.8% in female. 4. The relative frequency of current or past infection and chronic carrier among HBV infected person was estimated. The currently or past infected was estimated 75.7% in male and 71.8% in female, and chronic carrier state, 13.8% in male and 14.1% in female. The analysis of the geometric mean of the antibody titer in anti-HBs positive sera indicated also to be compatible with the above findings, suggesting that active, even though inapparent, infection of HBV occur so frequently among healthy adults in Korea.

• Clinical and Experimental Pediatrics
• /
• v.50 no.3
• /
• pp.262-267
• /
• 2007

Purpose : The prevalence of hepatitis A virus (HAV) in a certain community reflects that community's living standards and hygienic conditions. And the pattern of HAV infection differs over time and geography. Recently, a shift in prevalence has been observed in cases from chilhood to adulthood. We studied the HAV antibody prevalence in the general population in Busan. Methods : From October 2004 to March 2005, total 472 subjects were tested for HAV antibodies. All samples were collected from patients in Maryknol Hospital. Results : The overall seropositive rate was 22.8% (108/472). The seropositive rates were 1.7% in subjects aged 2-5 years, 1.7% in 6-10 years, 0% in 11-20 years, 40.5% in 21-30 years, 82.1% in 31-40 years, 94.7% in 41-50 years, and 100% in subjects aged over 50 years. There was no significant gap between gender groups. Conclusion : As the socioeconomic conditions in Korea have improved, the HAV seropositive rate in school-aged children has dramatically decreased in the last 20 years. But, the seropositive rate of HAV didn't differ according to gender. The seropositive rate of HAV in the pediatric group was very low, which suggests the increasing possibility of clinical HAV infection in adults in the near future. Therefore, we should actively prevent the spread of hepatits A virus. In order to do that, we need to reorganize our lifestyle and personel hygiene and carry out active and passive immunization to high risk groups.