• Korean Journal of Poultry Science
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• v.38 no.1
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• pp.13-19
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• 2011

In January 2010, high mortalities of ducklings occurred in two adjacent farms. Ducklings in farm A showed neurologic signs including paddling, opisthotonus and lameness, but ducklings from farm B had no specific clinical signs. At post mortem, diffused hemorrhagic spots in the liver and hemorrhages in the small intestine were observed in ducklings from farm A, and ducklings from farm B had only proventricular ulceration. Microscopically, multiple necrosis of hepatocytes, hyperplasia of the bile ducts, hemorrhages, infiltration of lymphocytes and bacterial colonies were commonly observed in the liver of ducklings from both farms. Also, type A and C duck hepatitis virus (DHV) were isolated from farm A and farm B, respectively and Salmonella typhimurium was commonly isolated and identified serologically and biochemically. To our knowledge, this is the first report about the co-infection of DHV and Salmonella typhimurium in ducklings, and co-circulation of type A and C duck hepatitis viruses in Korea.

• Food Science and Preservation
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• v.21 no.2
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• pp.170-174
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• 2014

Hepatitis A virus (HAV) infection leads to acute liver failure and death through the intake of contaminated food. The polymerase chain reaction (PCR) has been used to detect HAV in food samples. HAV detection takes a long time, however, due to the virus concentration step required before PCR assay. In this study, a rapid method of detecting the HAVs present in lettuce using immunomagnetic separation combined with quantum dots (IMS-QDs) assay was developed. The detection limit of IMS-QDs for HAV was 10 $TCID_{50}/mL$, similar to the result that was obtained using RT-PCR combined with PEG or IMS. The application of IMS-QDs assay completed the viral detection within one hour, but this was not possible using PEG combined with RT-PCR. In conclusion, IMS-QDs assay is a rapid and efficient method for detecting HAV at a low concentration in agricultural products.

• 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.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.

• Journal of Life Science
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• v.32 no.12
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• pp.919-928
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• 2022

As seen in the COVID-19 pandemic, unexpected emergence of new viruses presents serious concern on public health. Especially, the absence of effective vaccines or antiviral drugs against emerging viruses significantly increases the severity of disease and duration of viral circulation among population. Natural products have served as a major source for safe and effective antiviral drugs. In this study, we examined the virucidal activity of medical herb extracts with a view to discover novel antiviral agents with desired levels of safety and antiviral efficacy. Ethanol extracts of ten selected medical herbs were tested for antioxidant activity and in-vitro cytotoxicity in various animal cell lines. Of note, the herbal extracts showed broad and potent virucidal activities against rotavirus, hepatitis A virus, and influenza A virus. The extracts of Sorbus commixta and Glycyrrhiza uralensis showed strong virucidal activities against influenza A virus. We also examined whether the extracts of Sorbus commixta and Glycyrrhiza uralensis can be used as inactivating agents to prepare an inactivated viral vaccine. In a mouse model, influenza A virus inactivated by the extracts elicited high levels of neutralizing antibodies, and the vaccination provided complete protection against lethal challenge. These results suggest that herb-derived natural products can be developed to antiviral drugs as well as inactivating agents for preparation of inactivated viral vaccines.