• Korean Journal of Clinical Laboratory Science
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• v.45 no.3
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• pp.102-107
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• 2013

Hepatitis A (HA) is an acute infectious disease of the liver caused by the Hepatitis A virus (HAV). In acute HA, the presence of anti-HAV IgM is detectable and about 3 weeks after exposure, its titre increases over 4 to 6 weeks. Anti-HAV IgG is detectable within a few days of the onset of symptoms. IgG antibodies continue to last for years after infection and provide lifelong immunity to the host. This study was performed to investigate the current seroprevalence of anti-HAV antibodies in Jeonbuk province, South Korea. A total of 591 (male 322, female 269) serum samples were collected in July 2011 to June 2012. We tested the antibodies of anti-HAV IgG and IgM using a Modular E170 (Roche Diagnostics, Germany), and analysed the serum alanine aminotransferase (ALT) levels by HITACH 7600-100 (HITACH, Japan). The overall seroprevalence of anti-HAV IgG was 84.6% (500/591), and the rate of females (85.9%) was higher than males (83.5%). According to the decade of age, seroprevalence of anti-HAV IgG were as follows; 68.8% (11/16) in the under 10 years old category, 100% (19/19) in the 10~19 category, 96% (48/50) in the 20~29 category, 83.6% (56/67) in the 30~39 category, 84.3% (123/146) in the 40~49 category, 83.3% (135/162) in the 50~59 category, 83.1% (54/65) in the 60~69 category, 78.1% (32/41) in the 70~79 category, and 88% (22/25) in the over 80 category. Total seroprevalence of anti-HAV IgM was 3.4% (20/591), and according to gender, the seroprevalence of male (3.1%) was very similar to that of female (3.7%). Through this study, we know that the seroprevalence of anti-HAV antibody in north-west Jeonbuk province, South Korea, was high. Only children under the age of 10 remain susceptible to HAV infection. Vaccination against HAV is not needed at the present time for the people of Jeonbuk province, South Korea, but a vaccination should be recommended and the improvement in sanitary conditions and personal hygiene should be highlighted.

• Korean Journal of Clinical Laboratory Science
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• v.44 no.1
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• pp.1-6
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• 2012

Hepatitis A virus (HAV) is an epidemiologically important virus with a worldwide distribution. It causes acute hepatitis in humans. HAV infection is often subclinical or asymptomatic in children; however, symptomatic acute infections become more common with age. In this study, we investigated the prevalence of anti-HAV among hospital workers in Jeonbuk province. 447 (127 males, 320 females) persons were included in the study from January to June, 2011. Anti-HAV (total and IgM) in the sample serum was measured by VIDAS Hepatitis A (bioMerieux, France), and IgM positive samples were tested in terms of their serum alanine aminotransferase (ALT) levels by a HITACHI 7600-010 automatic analyzer (HITACHI, Japan). The overall prevalence of total anti-HAV was 45.9% (205/447), and rate for males (60.6%) was higher than that for females (40%). According to the age group, the prevalence rates of total anti-HAV were 20% (1/5) in those under 20 years old, 11.3% (18/160) in those 20-29 years, 49.7% (71/143) in those 30-39 years, 86.5% (83/96) in those 40-49 years, 92.9% (26/28) in those 50-59 years, and 40% (6/15) in those over 60 years old. The total prevalence of anti-HAV IgM was 0.8% (4/447), and rate for males (1.6%) was higher than that for females (0.6%). Through this study, we determined the prevalence of anti-HAV among hospital workers in Jeonbuk province. The prevalence of the HAV antibody overall was low in hospital workers under 40 years old and in those over 60 years old. Therefore, an improvement in sanitary conditions and hygiene and vaccinations against HAV in this population are recommended.

• Korean Journal of Clinical Laboratory Science
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• v.44 no.4
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• pp.210-215
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• 2012

Hepatitis virus infection is one of the major problems in Korea. To establish preventive measures for hepatitis A and B virus infection, study on sero-positivity of serum anti-HAV (aHAV) and anti-HBs (aHBs) is needed. The aim of this study was to analyze the sero-positivity and related factors of aHAV and aHBs. We analysed the sero-positivity of serum aHAV and aHBs using ICA (Immunochromatography Assay) method from 102 university students and employees and questionnaire survey was obtained characteristics, vaccination history, past history test, knowledge and information sources of the study subjects. Overall sero-positivity rates of serum aHAV and aHBs were 20.6% and 52.9%, respectively. The sero-positivity rate of aHBs was significantly different by gender (M, 34.9%; F,66.1%) and that of aHAV was significantly different by age (20 age group, 2.7%; 30 age group, 14.3%; 40 age group, 70%; 50 age group, 91.7%). Overall sero-positivity rates of serum aHAV and aHBs by vaccination history rates were 4.9% and 43.1%, respectively. Overall sero-positivity rates of serum aHAV and aHBs by past history test were 10.8% and 52.9%, respectively. Sero-positivity rates of serum aHAV was low in university students. The results of this study could be used effectively as a basic data for establishing effective preventive measures for hepatitis A including vaccination.

• Korean Journal of Clinical Laboratory Science
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• v.46 no.1
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• pp.17-21
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• 2014

The prevalence of hepatitis A virus (HAV) in a certain community reflects that community's living standard and hygienic condition. The seroprevalence rate of IgG anti-HAV has been changing with regions and times. In this study, we aimed to study the difference of seroprevalence of IgG anti-HAV according to sex, age and type of drinking water, and to know the vaccination rate and seroconversion rate for vaccinated subjects in Busan. A total of 644 samples were analyzed. The overall seroprevalence rate of IgG anti-HAV was 35.4% (228/644). There was no significant difference in sex (male 39.8%, female 32.7) (p>0.05). According to age, seroprevalence rate of anti-HAV were 55.0% in subjects aged 5~9 years old, 47.8% in 10~14 years old, decreced to 10.6% in 15~19 years old, 1.0% in 20~24 years old, 0.0% in 25~29 years old and increced with advacing ages ; 14.7% in 30~34 years old, 39.4% in 35~39 years old, 67.3% in 40~44 years old, 94.1% in 45~49 years old, 100.0% over 50 years (p<0.001). The seroprevalence of IgG anti-HAV was no statistical difference according to the types of drinking water (p>0.05). The vaccinated subject was 42 case only in below 25 years old. The seroconversion rate after vaccination was 88.1%.

• Biomedical Science Letters
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• v.17 no.1
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• pp.27-37
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• 2011

Hepatitis A virus (HAV) is a causative agent of triggering acute hepatitis which is transmitted by person-to-person contact and or fecal-oral route. In previous studies, most hepatitis A virus (HAV) isolates had been genotype IA in Korea. Recently, a small number of different genotypes were reported with an upsurge of acute hepatitis by HAV. Therefore, the distribution of HAV genotypes was investigated. RNA was extracted from anti-HAV IgM positive sera which were collected from February to August 2009, at a tertiary care hospital in eastern Jeonnam, Korea. Nested reverse transcription PCR and direct sequencing for VP1/P2A region of the HAV were performed. A total of 365 cases with suspected acute hepatitis were tested for anti-HAV IgM and positive results were obtained in 24 sera (9.0%), which were collected 2 to 15 days (median, 7 days) after the onset of symptoms. Of the 24 seropositive samples, 14 (58.3%) samples were positive for HAV RNA, among which 4 isolates (28.6%) were genotype IA and the other 10 (71.4%) were genotype IIIA. Both IA and IIIA genotypes were isolated from 5~6 neighboring administrative districts throughout the year without geographic or seasonal restrictions. HAV genotypes (IA and IIIA) were observed from the eastern Jeonnam for the studied.

• Clinical and Experimental Pediatrics
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• v.51 no.7
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• pp.690-695
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• 2008

The age-specific anti-hepatitis A virus (HAV) seroprevalence rates in South Korea have changed markedly since the last 2030 years with an improvement in the socio-economic, housing, and environmental-sanitation conditions. These changes are characterized by very low anti-HAV seropositive rates among individuals less than 30 years of age; however, nowadays, most adolescents and young adults at an increased risk of developing symptomatic HAV infections. The Korea Center for Disease Control Sentinel Surveillance System has recently revealed an increase in the incidence of hepatitis A infection since 2001 and has revealed a potential endemic nature of the hepatitis A infection. Hepatitis A vaccines that were introduced in 1997 in Korea have made the current anti-HAV IgG positive rates in children (less than 10 years of age) approximately 50% of the rates observed in Seoul in 2006. However, in the same year, a few children were diagnosed as having anti-HAV IgG antibodies in Busan. This suggests the presence of some difference in the vaccination policy among doctors practicing in Seoul and Busan. Thus, the current recommendation of vaccinating 12-year-old child with HAV vaccination should be emphasized and a new strategy should be developed for the vaccination program to cater to the adolescents and young adults who are not immune, as well as for persons who are at a high risk for hepatitis A viral infection such as military personnel and hospital and day care center employees. Further, urgent hepatitis A vaccinations are also needed in patients with chronic liver diseases.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.2
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• pp.229-235
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• 2015

Objectives: We checked hepatitis A virus antibody(anti-HAV IgG) and hepatitis B virus antibody(HBsAb) in three large companies. The result could be a guideline to establish proper health policy for Hepatitis A and B virus preventive plan in company. Methods: We investigated the seroprevalence of anti-HAV IgG and HBsAb, and demographic characteristics of employee volunteer in three companies in southern area of Korea. Company was divided three according to health policy for hepatitis A and B. Results: The seroprevalence rate of anti-HAV IgG in company A, B, and C was 53.6%, 25.8%, and 17.7%(P<0.001), respectively. The seroprevalence rate of HBsAb in workplace A, B, and C was 79.7%, 82.4%, and 70.9%(P<0.001), respectively. Anti-HAV IgG showed more considerable difference among the companies. Conclusions: The results confirmed that low rate of IgG anti-HAV and HBsAb, particularly in the company that had low level of hepatitis education and vaccination program. This study was important for establishing hepatitis education policies, to prevent and control outbreaks in companies.

• Microbiology and Biotechnology Letters
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• v.48 no.4
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• pp.564-568
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• 2020

Although studies on Hepatitis A virus (HAV) were crucial in the establishment of the HAV infection prevention programs, no systematic investigation into HAV has been conducted since 1999. We retrospectively analyzed the data between January 2010 to December 2018 from all the patients who underwent HAV antibody tests at the Dankook University Hospital Health Care Center. Data were collected from 56,204 individuals. Overall, 34,834 (62.0%) individuals from this cohort were positive for HAV antibodies and the annual rate of anti-HAV antibody positivity was highest in 2010 (68.5%) and lowest in 2013 (54.8%). The average decline in the antibody positivity rate was 0.62% per year, showing a statistically significant difference (p < 0.001). In the over 40s age group, anti-HAV antibody positivity rates decreased from 89% in 2010 to 64% in 2018 (p < 0.001), with an annual decrease of 3.1%. In the over 30s age group, it decreased from 48.2% in 2010 to 34.7% in 2018 (p < 0.001), with an annual decrease of 1.82%. This study shows that the antibody positivity rate is decreasing across age groups but given that HAV infection poses more significant risks in older patients it is important to expand the evaluations of the current and future antibody positivity rates for HAV in various age groups.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.2 no.1
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• pp.40-45
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• 1999

Purpose: The aim of this study is to investigate the seroepidemiology of hepatitis A and hepatitis B in Korean children. Methods: 801 children aged 6 to 12 years were enrolled. IgG antibody to hepatitis A virus (anti-HAV), hepatitis B surface antigen (HBsAg), antibody to HBsAg (anti-HBs), and IgG antibody to HBc (anti-HBc) were measured by radioimmunoassay. Results: Of the 801 children, the seroprevalence of anti-HAV was 0%. Three (0.4%) were seropositive for HBsAg. The seroprevalence of anti-HBs was 61.8%. Two (0.4%) of 495 anti-HBs positive subjects were positvie for anti-HBc. Of the 801 children, 658 (82.1%) had received hepatitis B vaccination. Conclusions: Since natural anti-HAV is not acquired in the childhood, the outbreak of hepatitis A is possible in adolescents and young adults. The decrease in seroprevalence of HBsAg and the increase in seroprevalence of anti-HBs might result from hepatitis B vaccination program in childhood.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.14 no.1
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• pp.67-73
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• 2011

Purpose: Recently, the incidence of acute hepatitis A has increased nationwide and is related to a low rate of IgG anti-HAV production. To establish effective measures for preventing hepatitis A virus infection, an epidemiologic study on the seroprevalence of anti-HAV is needed. Thus, we investigated the seroprevalence of IgG anti-HAV in children living in Gwangju and Jeonnam. Methods: IgG anti-HAV levels were measured in a total of 1,435 patients who visited Chosun University Hospital between January 2009 and December 2009. Results: The overall seropositve rate was 40.8% (586/1,435). The seropositive rates were 41% among children under the age of 1 year, 49.9% for children 1~5 years old, 51.1% among individuals 5~10 years old, 12.9% for individuals 10~15 years old, and 8.2% for subjects over 15 years old. There was no significant difference between genders in any group. The seropositive rates in Gwangju and Jeonnam were 57.3% and 32.9% for children under the age of 1 year, 52.5% and 44.3% for children 1~5 years old, 60.2% and 33.9% among children 5~10 years old, 14.1% and 9.7% for children 10~15 years old, and 10.8% and 4.2% for individuals over 15 years old. Conclusion: The results demonstrated the low rates of IgG anti-HAV, particularly among subjects over 10 years old, which suggests the possibility of increasing clinical HAV infection rates among adults in the near future. We should actively prevent the spread of hepatitis A virus. Vaccination is the most effective means of preventing hepatitis A virus transmission among persons at risk for infection. Hepatitis A vaccination is recommended for children who have low IgG anti-HAV seropositive rates.