• Parasites, Hosts and Diseases
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• v.52 no.1
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• pp.1-7
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• 2014

Plasmodium vivax reemerged in the Republic of Korea (ROK) in 1993, and is likely to continue to affect public health. The purpose of this study was to measure levels of anti-P. vivax antibodies using indirect fluorescent antibody test (IFAT) in border areas of ROK, to determine the seroprevalence of malaria (2003-2005) and to plan effective control strategies. Blood samples of the inhabitants in Gimpo-si, Paju-si, and Yeoncheon-gun (Gyeonggi-do), and Cheorwon-gun (Gangwon-do) were collected and kept in Korea Centers for Disease Control and Prevention (KCDC). Out of a total of 1,774 serum samples tested, the overall seropositivity was 0.94% (n=17). The seropositivity was the highest in Paju-si (1.9%, 7/372), followed by Gimpo-si (1.4%, 6/425), Yeoncheon-gun (0.67%, 3/451), and Cheorwon-gun (0.19%, 1/526). The annual parasite incidence (API) in these areas gradually decreased from 2003 to 2005 (1.69, 1.09, and 0.80 in 2003, 2004, and 2005, respectively). The highest API was found in Yeoncheon-gun, followed by Cheorwon-gun, Paju-si, and Gimpo-si. The API ranking in these areas did not change over the 3 years. The seropositivity of Gimpo-si showed a strong linear relationship with the API of 2005 (r=0.9983, P=0.036). Seropositivity data obtained using IFAT may be useful for understanding malaria prevalence of relevant years, predicting future transmission of malaria, and for establishing and evaluating malaria control programs in affected areas.

• Journal of Preventive Medicine and Public Health
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• v.37 no.3
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• pp.253-259
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• 2004

Objectives : To investigate the prevalence of hepatitis B and C virus infections and determine the associated risk factors among young adults in Busan, Korea, which is known to have a high incidence of liver cancer. Methods : The study population consisted of volunteer participants in a health survey during 2002, which included 1,350 students (515 males and 835 females) aged between 16 and 24 years, from three different schools in Busan. The participating students were asked to fill in a self-administered questionnaire which included lifestyle habits and risk factors of hepatitis. Sera obtained from the participants were studied for HBsAg, anti-HBs, and Anti-HCV by enzyme immunoassay (EIA) method and for liver function tests. Results : Among the study subjects (N=1,350), the seropositivities of HBsAg 7.9%(95% CI=7.8-8.0), 7.6%(95% CI=7.6-7.7) in male and 8.1%(95% CI=8.0-8.2) in female. And the seropositivity of Anti-HBs was 69.7%(95% CI=69.0-70.4), 70.5%(95% CI=69.8-71.2) in male and 69.2%(95% CI=68.5-69.9) in female. The seropositivity of Anti-HCV was 0.4%, 0.2% in male and 0.5% in female. The seropositivity for HBsAg in the subjects not having a hepatitis B vaccination history was twice(95% CI=1.0-4.4) that of those that did. Also, the seropositivity for HBsAg in subjects having experienced sexual intercourse was 1.7 times (95% CI=0.9-3.0) that of the subjects who had not. Conclusions : The present study confirmed the high prevalence of HBsAg seropositivity and sexual transmission of HBV among adolescents and young adults may occur. Further studies to evaluate the relationship between HBV vaccination and sexual transmission are required for the young population in Korea.

• Journal of applied mathematics & informatics
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• v.5 no.2
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• pp.301-301
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• 1998

• Journal of Preventive Medicine and Public Health
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• v.48 no.1
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• pp.53-61
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• 2015

Objectives: The seroprevalence of hepatitis E virus (HEV) among high-risk groups overseas is high, but studies in these groups are rare in South Korea. We conducted the present study from April to November 2012 to obtain data on the seroprevalence and associated risk factors for HEV among slaughterhouse workers in South Korea. Methods: Slaughterhouse workers from 80 workplaces nationwide were surveyed in South Korea in 2012. The subjects comprised 1848 cases: 1434 slaughter workers and 414 residual products handlers. By visiting 80 slaughterhouses, which were mixed with 75 of which also performed residual products handling, we conducted a questionnaire survey for risk factors and obtained blood samples in order to determine the seropositivity and seroprevalence of HEV. Anti-HEV IgG and IgM were measured using HEV IgG and IgM enzyme-linked immunospecific assay kits and HEV antigen was measured by reverse transcription polymerase chain reaction (RT-PCR). Results: The seropositivity of anti-HEV IgG was 33.5% (slaughter workers 32.8% and residual products handlers 36.2%), and among the seropositive individuals the seroprevalence of anti-HEV IgM was 0.5% (slaughter workers 0.5%, residual products handlers 0.7%). The response rate of HEV-antigen as measured by RT-PCR was 0.2%. Risk factors significantly related to anti-HEV IgG seropositivity were age, sex, and working duration (slaughter workers only). Conclusions: There were significant risk factors (sex, age, and working duration) for HEV identified in our study. All three positive cases for HEV-antigen by RT-PCR were related to pig slaughter but without statistical significance. To prevent HEV, an educational program and working guidelines may be needed for high risk groups.

• Parasites, Hosts and Diseases
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• v.59 no.4
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• pp.363-368
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• 2021

Despite the synergistic effect of Opisthorchis viverrini and Helicobacter pylori co-infection on pathogenesis of severe hepatobiliary abnormalities (HBA) including advanced periductal fibrosis and replace with cholangiocarcinoma (CCA) have been established, the immune response to H. pylori in O. viverrini infected population has never been explored. Hence, this study aimed to investigate the antibody responses to 2 immunogenic H. pylori proteins in O. viverrini-infected patients with HBA and CCA. The risk analysis by multinomial logistic regression revealed that GroEL seropositivity was associated with higher risks of hepatobiliary abnormalities and CCA with adjusted odds ratios (95% confidence intervals) of 2.11 (95% CI=1.20-3.71, P=0.008) and 2.13 (95% CI=1.21-3.75, P=0.009), respectively. These findings indicate that GroEL seropositivity might be a biomarker for early detection of O. viverrini associated HBA and CCA.

• Pediatric Infection and Vaccine
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• v.31 no.1
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• pp.1-11
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• 2024

Despite improvements in vaccine coverage, a resurgence of measles has been reported, especially in the infant and adult populations in recent years. We conducted a systematic review of seroprevalence studies conducted in the Western Pacific Region (WPR) to provide insights into seropositivity trends in different countries. This systematic review aimed to collect data from all available measles seroprevalence studies to characterize the differences in population immunity against measles in different countries. We searched the online databases PubMed and Embase to identify: 1) observational studies that investigated seroprevalence in all age groups, and 2) results reported as antibody levels. The following variables were extracted from different study arms: paper identification (title, first author, publication year), inclusion and exclusion criteria, study site, age of subjects, number of subjects, country/area, population, methods, and seropositivity (%). The search yielded a total of 69 studies included in the review. Among the 1-6-year-old group, seropositivity remained relatively high, at 81-100% in China, 86-94% in Korea, and 77-91% in Australia. In adolescents aged 7-18-years old, seropositivity was relatively constant in China and Australia over time; however, a decreasing trend was noted in Korea in 2011 (66%), 2014 (69%), and 2014 (50%) in this age group. A similar downward trend was observed among Korean adults aged 19-39 years in 2011 (74%), 2019 (71%), and 2019 (64%). Children are likely to be protected by universal vaccination programs in WPR countries and regions. However, susceptible individuals with waned immunity may be present among the adult population.

• The Journal of the Korean Society for Microbiology
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• v.35 no.1
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• pp.61-68
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• 2000

Among wild chipmunks, Tamias sibiricus, captured in Kyunggi and Kangwon province in Korea, 1997, seropositivity for Orientia tsutsugamushi was determined. Serological test for Orientia tsutsugamushi infection was performed using indirect immunofluorescent antibody technique (IFA). Of 243 wild chipmunks, 61 against Gilliam strain and 64 against Karp strain of Orientia tsutsugamushi were IFA positive. Seropositivity against Gilliam strain was shown 33.3% in Kyunggi and 23.5% in Kangwon province, and against Karp strain was shown 33.3% and 25.4%, respectively.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.4 no.2
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• pp.191-198
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• 2001

Purpose: This study was undertaken to investigate the seroepidemiologic pattern of Helicobacter pylori (H. pylori) and hepatitis A virus (HAV) infections in children. Methods: A total of 315 serum samples were obtained from healthy children, living in Gwangju and Chonnam area. All serum samples were assayed for H. pylori IgG level using enzyme immunoassay techniques. HAV IgG level in serum were tested by a competitive radio-immunoassay in 215 subjects. The age-specific seroprevalence of H. pylori and HAV was separately analysed. The concordance of seropositivity and seronegativity between H. pylori and HAV infection was examined by the kappa statistic analysis. Results: Seropositivity was found in 17.5% (55/315) and 30.2% (65/215) of the subjects for H. pylori and HAV, respectively. Cross-tabulation of these data showed that 21 subjects (9.8%) were seropositive and 135 (62.8%) were seronegative for both H. pylori and HAV, 15 (7.0%) were seropositive for only H. pylori and 44 (20.5%) for only HAV. The seroprevalence of H. pylori and HAV increased significantly with age. There was a slight agreement between H. pylori and HAV seropositivity (${\kappa}$=0.26). Conclusion: This study shows a slight similarity in the concordance of seropositivity and seronegativity between H. pylori and HAV infection and provides evidence that H. pylori and HAV may share a common mode of transmission.

• Pediatric Infection and Vaccine
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• v.4 no.1
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• pp.133-139
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• 1997

Purpose : To determine the age-specific seropositivity and the level of measles specific IgG in vaccinated adolescents, the measles specific IgG titers were measured from the sera of junior & senior high school students in Seoul, Korea. Methods : From May to July in 1996, 216 sera were collected from junior & senior high school students(male : 110, female : 106) aged 12 to 17 years who were vaccinated and had no history of natural measles. Measles specific IgG titers were measured using ELISA method($SIA^{TM}$ Measles IgG Kit, Sigma Co. St. Louis, Mo). Results : The seropositivity of measles specific IgG in vaccinated adolescents aged 12 to 17 years was 91.2%. There were no significant correlations between age and seropositivity as well as between age and measles specific IgG level. Conclusions : We consider that our data suggest the necessity of revaccination of measles in adolescents. Further considerations should be required to establish an appropriate revaccination method and to evaluate the efficacy of revaccination of previously vaccinated adolescents.

• Parasites, Hosts and Diseases
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• v.52 no.5
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• pp.487-491
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• 2014

Toxoplasma gondii is an obligate intracellular protozoan that is distributed worldwide. Recently, several tests for avidity of Toxoplasma IgG antibodies have been introduced to help discriminate between recently acquired and distant infections. The study was conducted in Jawaharlal Nehru Medical College and Hospital, India from February 2011 to September 2012. Serum specimens were subjected to Toxoplasma IgM ELISA and IgG avidity ELISA test. Out of 48 patients with abortions, 17 (35.4%) were positive for IgM ELISA, and 8 (16.6%) had low IgG avidity antibodies. Out of 48 patients with other obstetric problems, 23 (47.9%) were positive for IgM ELISA, and 17 (35.4%) had low IgG avidity antibodies. Combining both groups on avidity test, only 25 of 40 (62.5 %) IgM-positive women had low-avidity IgG antibodies suggesting a recent T. gondii infection in these women. More importantly, 15 (37.5%) of the IgM-positive women had high-avidity antibodies suggesting that the infection was acquired before gestation The relation of IgM seropositivity with the following risk factors was not found to be statistically significant; contact with cats (0.13), non-vegetarian food habits (0.05), and low socio-economic status (0.49). While, for IgG avidity ELISA, only contact with cats (0.01) was significantly associated with seropositivity. All other risk factors have P-values of >0.05 (not significant). IgG avidity test when used in combination with IgM test was a valuable assay for diagnosis of ongoing or recently acquired T. gondii infection in India.