• Clinical and Experimental Pediatrics
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• v.56 no.11
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• pp.465-473
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• 2013

The epidemiology of human group A rotavirus was analyzed by examining genotypic data acquired from 1989 to 2009 in South Korea. This information was derived from all the available published articles on rotavirus studies in South Korea, retrieved from both the PubMed and KoreaMed databases. Four common G types (G1, G2, G3, and G4) and three common P types (P[8], P[4], and P[6]) accounted for approximately 93% and 99% of the rotavirus reports, respectively. The G9 type was frequently detected after 2000, and because of this prevalence, it is considered to be the fifth most important G type rotavirus after the G1-G4 genotypes. Less common G types of the virus such as G12, G11, and G10 were detected in some geographic settings, and it is important to consider the context of these subtypes and their epidemiological significance. The P[9] virus genotype was observed in the study and has been discussed in many other studies; however, the P[3], P[10] and P[25] genotypes were rarely detected in the epidemiological research. In general, the distributions of the G and P genotypes showed temporal and geographical fluctuations, and a nationwide rotavirus vaccine program that targeted these genotypes demonstrated effectiveness in protecting against the circulating rotavirus strains. However, further analysis is needed to determine the true long-term effectiveness of these vaccines; the analysis should also consider the unexpected effects of vaccinations, such as vaccineinduced diseases, herd immunity, and changes in host susceptibilities.

• 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.

• Pediatric Infection and Vaccine
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• v.19 no.1
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• pp.19-27
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• 2012

Purpose : As the number of children who attend child care centers has increased, concerns has increased about the effect of child day care on childhood illness. This study was conducted to examine the relationship between experience in child care and common infectious diseases in children under 5 years of age. Methods : Data were collected by surveying 1,000 respondents with children under age 5 through online interviews using a structured questionnaire. The contents of the survey were composed of demographic characteristics, child care facilities usage, experience in infectious diseases, and immunization status Results : Among the 1,000 children <5 years of age, 78.5% attended a child care facility. Rates of common communicable illnesses were higher in children in child care than for children reared exclusively at home. The predominant communicable diseases which the respondents' children experienced, in order of decreasing frequency, were gastroenteritis (47.1%), otitis media (41.8%) and pneumonia (19.1%). The immunization rate of vaccines that are not included the national immunization program (NIP) (Haemophilus influenzae type b vaccine - 76.6%, hepatitis A vaccine - 63.3%, pneumococcal vaccine - 59.4%, rotavirus vaccine - 43.1%) was lower than that of the NIP vaccines (90.4%) Conclusion : Children in child care experience more bouts of common infectious disease, so nationwide policies to prevent or to control the spread of infectious agents in a child-care should be available and appropriate immunization should be emphasized as the most effective method for the control of infectious disease for children.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.23 no.4
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• pp.311-318
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• 2020

Chronic hepatitis B viral (HBV) infection remains a major health threat, especially in high-prevalence areas. Most infants infected by mother-to-infant HBV transmission become chronic carriers. In Taiwan, many important preventive interventions have been implemented to block the perinatal transmission of HBV in the past 35 years. The first nationwide universal HBV vaccination program was launched in Taiwan in July 1984. The three-dose HBV vaccine completion rate reached 98.1% in 2018. The prevalence of Hepatitis B surface antigen (HBsAg) decreased from 9.8% in pre-vaccinated period in 1984 to 0.5% in the vaccinated cohort in 2014. The incidence of hepatocellular carcinoma in children aged 6-9 years significantly declined from 0.52 to 0.13 per 100,000 children born before and after 1984, respectively. Furthermore, we have performed a maternal HBV screening program during pregnancy since 1984, with the screening rate peaked at 93% in 2012. The HBsAg- and HBeAg-seropositive rate in pregnant women declined from 13.4% and 6.4% in 1984-1985 to 5.9% and 1.0% in 2016, respectively. To closely control perinatal HBV infection, we have administered hepatitis B immunoglobulin immediately after birth and checked the serum level of HBsAg and anti-HBs in high-risk babies born to HBsAg-seropositive mothers, irrespective of their HBeAg status, since July 2019. We have also adopted short-term antiviral treatments such as tenofovir 300 mg daily in the third trimester for highly viremic mothers and reduced the perinatal infection rates from 10.7 to 1.5%. Through all these efforts, we expect to meet the global goal of eliminating HBV infection by 2030.

• Korean Journal of Poultry Science
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• v.37 no.4
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• pp.361-372
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• 2010

Serological evaluation for the poultry is important for various reasons, such as designing and assessing the vaccination program and diagnosing diseases and for this reason, serologic tests for the layer flocks have been conducted on a regular basis. Moreover, the nationwide serological survey and analysis are essential to understand the epidemiological status of national poultry industry. In this sense, the study was conducted to evaluate the immune status of the layer flocks with the sera submitted to Avian Disease Laboratory, Chungbuk National University in 2009, and several important viral diseases were selected for evaluation including low pathogenic avian influenza (LPAI), Newcastle disease (ND), infectious bronchitis (IB) and avian metapneumovirus (aMPV). For LPAI and ND, the age-related patterns of geometric mean titer (GMT) changes were similar but there were differences in the flock positive rate and the level of GMT due to the different vaccination policy. In the case of IB, the values of GMT showed that the field infection was more prevalent than expected. For aMPV, positive birds in a flock increased as the layers got older, which reflected the course of field infection because vaccination against aMPV was not allowed in 2009. From this study, the immune status for the main viral diseases in layers became more clarified but this information was limited because of only one year study. Therefore, serological survey needs to be conducted on a yearly basis and furthermore include broilers and breeders for a better understanding of the health status in the national poultry industry.