• Journal of Preventive Medicine and Public Health
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• v.40 no.1
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• pp.23-28
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• 2007

Objectives : Chronic infections with hepatitis B or C and alcoholic cirrhosis are three well-known major risk factors for liver cancer. Diabetes has also been suggested as a potential risk factor. However, the findings of previous studies have been controversial in terms of the causal association. Therefore, the aim of this study was to evaluate the association between serum glucose levels and liver cancer development in a Korean cohort. Methods : Thirty-six liver cancer cases were identified in the Korean Multi-Center Cancer Cohort (KMCC). Baseline information on lifestyle characteristics was obtained via questionnaire. Serum glucose levels were measured at the study's enrollment. Relative risks (RRs) were estimated using a Cox proportional hazard regression model. The adjusting variables included age, gender, smoking history, alcohol consumption, body mass index, and hepatitis B surface antigen (HBsAg) seropositivity. Results : The RRs of serum glucose for liver caner were 1.20 (95% CI = 0.48-2.99) for the category of 100 to 125 mg/dL of serum glucose and 2.77 (95% CI = 1.24-6.18) for the >126 mg/dL serum glucose category (both compared to the <100 mg/dL category). In a subgroup analysis, the RR of serum glucose among those who were both HBsAg seronegative and non-drinkers was 4.46 (95% CI = 1.09-18.28) for those with glucose levels >100 mg/dL. Conclusions : The results of this study suggest that a high level of serum glucose can increase liver cancer risk independently of hepatitis infection and drinking history in Koreans. This study implies that glucose intolerance may be an independent risk factor for liver cancer.

• Biomedical Science Letters
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• v.3 no.2
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• pp.95-105
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• 1997

Currently, the laboratory diagnosis for lyme disease have been performed with the detection of antibodies against Borrelia burgdorferi. However there might be some difficulties in the interpretation of obtained results due to the usage of foreign isolates as an antigen in the test. Therefore the optimization of serological tests with Korean isolates of B. burgdorferi as an antigen would be needed to establish the standardized diagnostic method for the detection of antibodies against B. burgdorferi infection. In this study, the optimization of ELISA was investigated with experimentally challenged rabbit sera and sonicated B. burgdorferi antigens of Korean isolates. Of 217 human patient's sera with unknown fever, the mean seropositivities in ELISA, done under the optimized conditions obtained in this study, were found to be about 8％ against B. burgdorferi sensu late, showing the highest seropositivity of 14.3％ against B. afzelii. In immunoblotting assay with ELISA-positive human sera, the major reactive bands were 41kDa (flagellin) which might be the indication of early infection, and 27kDa, 31kDa (OspA), 34kDa (OspB) which are the characteristics of late infection. Obtained results in this study might strongly indicate the possibility of B. burgdorferi infections in Korea.

• Parasites, Hosts and Diseases
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• v.50 no.4
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• pp.287-293
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• 2012

Knowledge of the prevalence of human Toxoplasma gondii infection is required in the Republic of Korea. In this study, we surveyed the seroprevalence of T. gondii infection and analyzed the risk factors associated with seropositivity among residents in 2 administrative districts; Seoul and the island of Jeju-do, which have contrasting epidemiologic characteristics. Sera and blood collected from 2,150 residents (1,114 in Seoul and 1,036 in Jeju-do) were checked for IgG antibody titers using ELISA and for the T. gondii B1 gene using PCR. In addition, participants completed a questionnaire that solicited information on gender, age, occupation, eating habits, history of contact with animals, and travel abroad. The T. gondii B1 gene was not detected in all residents examined. However, ELISA showed 8.0% (89 of 1,114 sera) positive for IgG antibodies against T. gondii in Seoul and 11.3% (117 of 1,036 sera) in Jeju-do. In both districts, the positive rates were higher in males than in females, and those 40-79 years of age showed higher rates than other ages. In Seoul, residents older than 70 years of age showed the highest positive rate, 14.9%, whereas in Jeju-do the highest prevalence, 15.6%, was in those in their sixties. The higher seropositive rate in Jeju-do than in Seoul may be related to eating habits and occupations. The present results and a review of related literature are indicative of an increased seroprevalence of T. gondii in Korea in recent years.

• Journal of Preventive Medicine and Public Health
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• v.38 no.4
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• pp.431-436
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• 2005

Objectives : We investigated the seroprevalence of the measles antibody and its at tributable factors for the students who underwent routine 2-dose Schedule Era. Methods : The subjects were 996 students of the national measles seroepidemiologic study in December 2000 who had vaccination records. We conducted a questionnaire survey and we performed serologic testing for the measlesspecific IgG by using an enzyme linked immunosorbent assay. Results : The coverage for the first dose of the MMR vaccination at 12-15 months of age was 95.1% and the coverage for the second dose of MMR at 4-6 years of age was 35.0%. The proportion of subjects undergoing 2-dosesof MMR dec reased as the age of the subjects increased. The seropositive rate of the measles antibody was significantly high in the second dose vaccinees (93.5% in the second dose group, 84.7% in the non-second dose group, p<0.001) and it was 72.0% in the 0-dose group, 85.4% in the 1-dose group and 93.7% in the 2-dose group (p<0.001). Two point eight percent of the subjects had a past history of measles infection. On the multiple logistic regression analysis, the first and second dose (odds ratio, 8.54; 95% CI.=3.05-23.91), the first dose (odds ratio, 3.06; 95% CI.=1.20-7.81) and the outbreak in the year 2000 (odds ratio, 1.89; 95% CI.=1.24-2.88) were the significant factors for the seropositivity. Conclusions : Maintaining high coverage with a 2-dose vaccination program would be the decisive factor to prevent an outbreak of measles and to eliminate measles in Korea.

• Journal of Neurogastroenterology and Motility
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• v.24 no.4
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• pp.603-613
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• 2018

Background/Aims Functional dyspepsia (FD) is one of the most common gastrointestinal disorders, and FD imposes social and economic burden worldwide. The aim of this study is to identify the prevalence and risk factors of FD in health check-up population in tertiary centers in Korea. Methods A nationwide multicenter prospective study was performed at 9 tertiary healthcare centers in Korea between September 2016 and June 2017. A total of 2525 subjects were investigated based on endoscopic findings and questionnaires with the Rome III criteria, and Helicobacter pylori serology (IgG). Results A total of 1714 subjects without organic disease were enrolled. The mean (${\pm}SD$) age was 51.5 (${\pm}12.7$) years, and 917 patients (53.5%) were female. The proportion of H. pylori seropositivity was 51.0% (874/1714). The prevalence of FD was 10.3% (176/1714), and the subtypes of postprandial distress syndrome alone, epigastric pain syndrome alone, and postprandial distress syndromeepigastric pain syndrome overlap were 4.8%, 3.0%, and 2.5%, respectively. Multivariate analysis showed that female gender (OR, 1.58; 95% CI, 1.14-2.21) and education below college level (OR, 1.45; 95% CI, 1.01-2.07) were related to FD. Multivariate analysis based on age 60 showed female gender as a significant (OR, 2.90; 95% CI, 1.06-7.94) factor in the group ${\geq}60$ years. Conclusions The prevalence of FD was 10.3% in the health check-up population in Korea. Female sex and education below college level were risk factors for FD. Female sex is a risk factor for FD in old age, underscoring the need for close attention in this age group.

• Journal of agricultural medicine and community health
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• v.44 no.1
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• pp.1-10
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• 2019

Objectives: This study aimed to assess the status of Scrub typhus, Leptospirosis and HFRS(hemorrhagic fever with renal syndrome) among farmers with febrile illness. Methods: We involved a total of 841 farmers who had febrile illness(508 and 333 village residents were, respectively, three and four district of Gyeongju city) selected during autumn of 2014 and 2015. Data were collected by survey questionnaires and blood sample examination. Results: Serum response rate for Scrub typhus and Leptospirosis was 1.5% each and 1.9% for HFRS. Serum response rate for Scrub typhus was significantly higher for tick-bite cases(38.5%), while Leptospirosis was significantly higher for those who were in fruit-planting work(23.1%). Similarly, serum response rate was significantly higher for HFRS who were working in venyl green house work(25.0%). Conclusions: Government authority should develop effective and efficient preventive strategies to create awareness of infectious diseases among farmers. Extending information, education and communication be reached to farmers that could change their perception and help early diagnosis and treatment and reduce the disease burden and its complication.

• Parasites, Hosts and Diseases
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• v.58 no.6
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• pp.609-617
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• 2020

Plasmodium vivax reemerged in 1993. It has been sustained for more than 25 years and become one of the important indigenous parasitic diseases in northern and western parts of the Republic of Korea near the demilitarized zone. In particular, relapse is a significant concern for the control of malaria, as short- and long-term incubation periods vary among those infected in Korea. In this study, the prevalence of asymptomatic carriers was examined among residents of high endemic areas of vivax malaria during nonseasonal transmission of mosquitoes. Blood samples from 3 endemic regions in northwestern Korea were evaluated by microscopic examination, rapid diagnostic testing, and nested PCR to identify asymptomatic patients carrying malaria parasites in the community. However, no positive malaria case among residents of endemic areas was detected. Additionally, serological analysis was carried out to measure antibodies against 3 antigenic recombinant proteins of P. vivax, merozoite surface protein 1-19, circumsporozoite surface protein-VK210, and liver-stage antigen (PvLSA-N), by the protein array method. Interestingly, seropositivity of sera between previous exposure and samples without exposure to malaria was significantly higher using the PvLSA-N antigen than the other antigens, suggesting that PvLSA-N can be used as a serological marker to analyze the degree of exposure for malaria transmission in endemic areas. This indicates a very low asymptomatic carrier prevalence during the nonmalaria season in the endemic areas of Korea.

• Parasites, Hosts and Diseases
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• v.58 no.5
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• pp.487-492
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• 2020

Toxoplasmosis is caused by an obligate intracellular protozoan parasite; Toxoplasma gondii, which is one of the most important zoonotic parasite worldwide. In dogs, the sexual reproductive cycle of T. gondii is lacking, and the animals are not widely consumed as food, but they are vital in the mechanical transmission of the parasite. However, there is no present data on the exposure of stray dogs to T. gondii in Malaysia. The objective of this serological survey was to determine the prevalence of T. gondii antibodies (IgG) and associated factors in stray dogs in East and West Malaysia. Antibodies to T. gondii were determined in serum samples from 222 stray dogs from 6 different states in East and West Malaysia (Peninsular Malaysia) using an Indirect ELISA. The seroprevalence for T. gondii was 23.4% (Confidence interval: CI 17.8-29.2%). Stray dogs from Selangor and Kuala Lumpur had the highest seroprevalence (32.4%; CI 13.2-45.5%) and lowest in those from Penang and Kedah (12.5%; CI 1.3-23.5%). Gender and breed were not associated with T. gondii seropositivity. However, adult dogs were more likely to be seropositive for T. gondii (OR=2.89; CI 1.1-7.7) compared with younger dogs. These results revealed that T. gondii is prevalent in stray dogs in the studied areas in Malaysia, and indicative of the level of environmental contamination of this parasite especially in urban areas.

• Pediatric Infection and Vaccine
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• v.8 no.2
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• pp.150-159
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• 2001

Purpose : We need to reconsider booster vaccination schedule of Japanese encephalitis vaccination. To do that we evaluate the long-term immunogenicity and the incidence of adverse events with inactivated mouse brain derived Nakayama Japanese encephalitis vaccine. Methods : We tested neutalizing antibody for 311 elementary school students by plaque reduction neutralizing test(PRNT) at USAMC-AFRIMS(United States Armed Forces Research Institute of Medical Science/Department of Virology). We evaluated vaccine related adverse events by spontaneous reporting prospectively among 15,487 vaccinees who were vaccinated at public health center and 2,277 elementary school students who were immunized previously by a questionnaire and school health record. Results : According to the time interval from the last booster injection of 311 children, PRNT antibody titers gradually decreased as the interval increased; 239 mIU/mL, 188 mIU/mL, 134 mIU/mL, 49 mIU/mL each at 6, 18, 30, 42 months after the last booster injection. The seropositivity rates were 98%, 99%, 95.6%, 71.4% each at 6, 18, 30, 42 months after the last booster injection. There were 21(0.13%) cases with systemic reactions among 15,487 vaccinees who had visited the hospital by prospective passive reporting system at public health center. According to the questionnaires and school health records in elementary school students, local induration and pain were 17.4% and 14.8%, respectively. Systemic reactions including fever, vomiting, rash were reported in few cases. Conclusion : Biannual booster vaccination that has been recommended so far should not be necessary. Surveillance for adverse events with inactivated mouse brain derived Nakayama vaccine should be strengthened to better assess the number of cases and reactions associated with immunization.

• Journal of Preventive Medicine and Public Health
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• v.29 no.3 s.54
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• pp.669-678
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• 1996

Helicobacter pylori is now recognized as causative agent of chronic gastritis and peptic ulcer, and strongly associated with development of gastric carcinoma. With development of sensitive and specific serologic tests to identify individuals infected with Helicobacter pylori, the epidemiologic study of this diseases has been investigated. But it's transmission route is not established, yet. The purpose of this study is to measure the prevalence of Helicobacter pylori infection in healthy children and young adults and to evaluate related factors for Helicobacter pylori infection in Korea. The seroprevalence of Ig G antibodies to Helicobacter pylori was determined using a Enzyme Linked Immunosorbent Assay and we obtained the information, such as demographic characteristics, monthly household income, numbers of family members in the house, numbers of persons using same room, type of house, and type of drinking water through the questionnaire survey. The observed overall seropositivity rate was 25.7%. The rate is increased progressively from 5.8% in the age group $1\sim3$ years to 44.4% in the age group $20\sim29$years($\chi^2$ for trend, p<0.001). Especially, the rate increased steeply from 6.5% in the age group $4\sim6$ years to 20.8% in the age group $7\sim9$ years, and this suggested that elementary school age was the major acquisition time of Helicobacter pylori infection. In multivariate logistic regression model, age, numbers of family members in the house, and type of house was statistically significant variables for Helicobacter pylori infection. Each odds ratio(93% CI) were as follows; base to age group $1\sim9$ years, age group $10\sim19$ years $3.6(2.0\sim6.4)$, age group $20\sim29$ years $7.3(4.1\sim13.1)$ and base to group of $1\sim3$ family members, group of $4\sim5$ family members $2.1(1.1\sim4.0)$, group of 6 or more family members $2.7(1.3\sim5.4)$ and base to apartment, single and multihouse $1.9(1.1\sim3.5)$. Sex, monthly household income, numbers of persons using same room, and type of drinking water was not statistically significant for Helicobacter pylori infection.