• Korean Journal of Microbiology
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• v.39 no.4
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• pp.242-247
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• 2003

Murine encephalomyocarditis virus (EMCV) has been used as a surrogate for hepatitis A virus (HAV) for the validation of virus removal and/or inactivation during the manufacturing process of biopharmaceuticals. Recently international regulation for the validation of HAV safety has been reinforced because of the reported cases of HAV transmission to hemophiliac patients who had received ntihemophilic factors prepared from human plasma. The purpose of the present study was to compare the resistance of HAV and EMCV to various viral inactivation processes and then to standardize the HAV validation method. HAV was more resistant than EMCV to pasteurization (60oC heat treatment for 10 hr), low pH incubation (pH 3.9 at 25oC for 14 days), 0.1 M NaOH treatment, and lyophilization. EMCV was completely inactivated to undetectable levels within 2 hr of pasteurization, however, HAV was completely inactivated to undetectable levels after 5 hr treatment. EMCV was completely inactivated to undetectable levels within 15 min of 0.1 M NaOH treatment, however, residual infectivity of HAV still remained even after 120 min of treatment. The log reduction factors achieved during low pH incubation were 1.63 for HAV and 3.84 for EMCV. Also the log reduction factors achieved during a lyophilization process of antihemophilic factor VIII were 1.21 for HAV and 4.57 for EMCV. These results indicate that HAV rather than EMCV should be used for the virus validation study and the validation results obtained using EMCV should be precisely reviewed.

• 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.

• Korean Journal of Food Science and Technology
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• v.44 no.5
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• pp.638-642
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• 2012

Human pathogenic viruses such as hepatitis A and E virus (HAV and HEV), which lead to acute liver failure and death, are foodborne pathogens associated with the consumption of virus-contaminated meats, filter-feeding bivalves, fruits, and salads. Two of the three swine farms examined in this study had HAV and HEV positive stool samples in a nested RT-PCR assay. The use of the immunomagnetic separation (IMS) facilitated the separation of HAV through interactions between the ligand on the virion surface and the antibody from the swine feces containing both HAV and HEV. The nested RT-PCR analysis was performed for the detection of HAV obtained from hepatocarcinoma cell line (PLC/PRF/5) contaminated with eluent fraction of IMS. This indicated that IMS has the potential to simultaneously isolate and concentrate target viruses by changing antibodies linked on the magnetic beads.

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

• 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.

• 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 Infection and Vaccine
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• v.6 no.2
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• pp.234-238
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• 1999

Purpose : This study was performed to evaluate the seropositivities and levels of Hepatitis A Virus(Hav) antibody in term pregnant women and their neonates, and the transplacental transfer rate of maternal Hav-specific IgG(Hav IgG) from tenn pregnant women to their neonates. Methods : During Jan. 1st, 1998 to May. 31 tho 1998, we collected the 42 pairs of sera from pregnant women and umbilical cord of their neonates in Korea University Ansan Hospital. The serum levels of Hav IgG were measured by the RIA method. Results : 1) The seropositivities of Hav IgG were 78.6% in mothers and 81.0% in neonates. There was no statistical difference of mean antibody(Ab) levels between mothers and neonates. There was significant correlation of Ab levels between maternal sera and neonatal umbilical cord sera(correlation coefficient r=0.9285, P<0.001). 2) There were no significant correlations between neonatal Hav IgG level and other factors such as maternal age, gestational age and initial body weight of neonates. Conclusion : Seropositivities of Hav IgG tenn-pregnant women was comparable to those of their neonates. Pregnant women and their neonates can be protected from Hav infection.

• 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.

• Journal of Microbiology and Biotechnology
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• v.26 no.8
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• pp.1398-1403
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• 2016

The simultaneous detection and accurate identification of hepatitis A virus (HAV) is critical in food safety and epidemiological studies to prevent the spread of HAV outbreaks. Towards this goal, a one-step duplex reverse-transcription (RT)-PCR method was developed targeting the VP1/P2B and VP3/VP1 regions of the HAV genome for the qualitative detection of HAV. An HAV RT-qPCR standard curve was produced for the quantification of HAV RNA. The detection limit of the duplex RT-PCR method was 2.8 × 10¹ copies of HAV. The PCR products enabled HAV genotyping analysis through DNA sequencing, which can be applied for epidemiological investigations. The ability of this duplex RT-PCR method to detect HAV was evaluated with HAV-spiked samples of fresh lettuce, frozen strawberries, and oysters. The limit of detection of the one-step duplex RT-PCR for each food model was 9.4 × 10² copies/20 g fresh lettuce, 9.7 × 10³ copies/20 g frozen strawberries, and 4.1 × 10³ copies/1.5 g oysters. Use of a one-step duplex RT-PCR method has advantages such as shorter time, decreased cost, and decreased labor owing to the single amplification reaction instead of four amplifications necessary for nested RT-PCR.