Search results for "Hepatitis A Virus"
showing 10 items of 23 documents
Effect of green tea extract on enteric viruses and its application as natural sanitizer
2017
In this work, the effect of green tea extract (GTE) was assessed against murine norovirus (MNV) and hepatitis A virus (HAV) at different temperatures, exposure times and pH conditions. Initially, GTE at 0.5 and 5 mg/ml were individually mixed with each virus at 5 log TCID50/ml and incubated 2 h at 37 °C at different pHs (from 5.5 to 8.5). GTE affected both viruses depending on pH with higher reductions observed in alkaline conditions. Secondly, different concentrations of GTE (0.5 and 5 mg/ml) were mixed with viral suspensions and incubated for 2 or 16 h at 4, 25 and 37 °C at pH 7.2. A concentration-, temperature- and exposure time-dependent response was showed by GTE in suspension tests, w…
Polymers and Biopolymers with Antiviral Activity: Potential Applications for Improving Food Safety
2018
Gastroenteritis and hepatitis, caused by human noroviruses (HuNoVs) and hepatitis A virus (HAV), respectively, are the most common illnesses resulting from the consumption of food contaminated with human enteric viruses. Food-grade polymers can be tailor designed to improve food safety, either as novel food-packaging materials imparting active antimicrobial properties, applied in food contact surfaces to avoid cross-contamination, or as edible coatings to increase fresh produce's shelf life. The incorporation of antimicrobial agents into food-grade polymers can be used to control the food microbiota and even target specific foodborne pathogens to improve microbiological food safety and to e…
Effect of (−)-epigallocatechin gallate at different pH conditions on enteric viruses.
2017
Epigallocatechin gallate (EGCG), a flavonoid from green tea, is said to have extensive antimicrobial activity in a wide range of food spoilage or pathogenic fungi, yeast and bacteria. In this work, the antiviral activity of EGCG was assessed against hepatitis A virus (HAV) and murine norovirus (MNV), a human norovirus surrogate, at different temperatures, contact times and pH conditions by cell-culture methods. EGCG was effective in reducing the titers of HAV and MNV in a dose-dependent manner at neutral pH and 25 and 37 °C, while no effect was reported at 4 °C. HAV and MNV infectivity was completely removed after overnight treatment with EGCG at 2.5 mg/mL at 37 °C. Furthermore, results als…
Improving efficiency of viability-qPCR for selective detection of infectious HAV in food and water samples.
2017
Aim: To improve the efficacy of intercalating dyes to distinguishing between infectious and inactivated hepatitis A virus (HAV) in food. Methods and Results: Different intercalating dyes were evaluated for the discrimination between infectious and thermally inactivated HAV suspensions combining with the RT‐qPCR proposed in the ISO 15216. Among them, PMAxx was the best dye in removing the RT‐qPCR signal from inactivated HAV. Applied to lettuce and spinach, PMAxx–Triton pretreatment resulted in complete removal of the RT‐qPCR signal from inactivated HAV. Likewise, this study demonstrates that this pretreatment is suitable for the discrimination of inactivated HAV in shellfish without further …
Differential genetic determination of immune responsiveness to hepatitis B surface antigen and to hepatitis A virus: a vaccination study in twins.
2002
Summary Background The course of viral hepatitis is thought to be affected by genetic host variability and, in particular, by genes of the major histocompatibility locus. Hepatitis A and B vaccination is a useful model to study the effect of host factors on the immune response to viral antigens. We aimed to assess the heritability of the HBsAg (anti-HBs) and anti-hepatitis A virus (anti-HAV) immune response and to estimate the effect of the HLA-DRB1 locus and other genetic loci unlinked to HLA. Methods We did an open prospective study and vaccinated 202 twin pairs with a combined recombinant HBsAg/inactivated hepatitis A vaccine. We measured antibodies to HBsAg and HAV and determined HLA-DR…
Anti-hepatitis A virus seroprevalence and seroconversion in a cohort of patients with chronic viral hepatitis
2002
Abstract Background. Patients with chronic hepatitis C infected by hepatitis A virus have a substantial risk of fulminant hepatitis or death, while the course of hepatitis A virus is uncomplicated in most subjects with chronic hepatitis B. Aim. To evaluate the prevalence of anti-hepatitis A virus antibodies and the incidence of hepatitis A virus seroconversion in a nationwide sample of 530 patients with chronic hepatitis B and/or hepatitis C infection initially susceptible to this infection after a follow-up of some years. Results. The overall anti-hepatitis A virus prevalence was 85.7%, with no difference between males and females. By the age of 50 years, almost all patients were found to …
Exposure to HAV infection in patients with chronic liver disease in Italy, a multicentre study*.
2005
Summary. We carried out a multicentre study on 2830 patients with chronic liver disease from 79 liver units (25 in northern, 24 in central and 30 in southern Italy) to evaluate naturally acquired immunity against hepatitis A virus (HAV) in relation to age, sex, geographical area of origin and entity of liver disease, and to define the strategy for specific vaccination. Antibody to HAV (anti-HAV) was detected in 1514 (53.5%) of the 2830 patients tested; the prevalence was 50.4% in males and 59.1% in females. Both in central and southern Italy the prevalence of anti-HAV positive subjects increased with increasing age from 43.3 and 44.7%, respectively, in the 0–30-year-old subjects to 80.1 an…
Incidence of HAV and HBV infections and vaccination rates in patients with autoimmune liver diseases.
2007
Hepatitis A virus (HAV) or hepatitis B virus (HBV) superinfection is associated with an increased mortality in patients with chronic liver diseases (CLD). Despite official recommendations, it was reported that the vaccination rate against HAV is low in patients with chronic hepatitis C infection. To evaluate the situation in patients with autoimmune liver diseases, we conducted a retrospective cohort study.Susceptibility to HAV and HBV infections, course of HAV and HBV infections, vaccination rates against HAV and HBV, and efficacy of hepatitis A/B vaccines were evaluated by antibody testing in 225 patients with autoimmune liver diseases during 1,677 person-years.Susceptibility to HAV/HBV i…
Antiviral activity of alginate-oleic acid based coatings incorporating green tea extract on strawberries and raspberries
2018
Foodborne illnesses caused by the consumption of berries contaminated with human enteric viruses, namely human noroviruses (NoVs) and the hepatitis A virus (HAV), remain a significant food safety concern. The objective of this research was to investigate a food-grade edible coating composed of alginate/oleic and containing green tea extract (GTE) as an antiviral agent for the preservation of fresh strawberries and raspberries. Berries were stored at ambient (25 °C) temperature and refrigerated (10 °C) conditions. Initially, the effect of the pH of the film-forming dispersions (FFD) on their antioxidant and antiviral activity was analysed. Then, the physicochemical properties of edible algin…
Application of viability PCR to discriminate the infectivity of hepatitis A virus in food samples.
2015
Abstract Transmitted through the fecal–oral route, the hepatitis A virus (HAV) is acquired primarily through close personal contact and foodborne transmission. HAV detection in food is mainly carried out by quantitative RT-PCR (RT-qPCR). The discrimination of infectious and inactivated viruses remains a key obstacle when using RT-qPCR to quantify enteric viruses in food samples. Initially, viability dyes, propidium monoazide (PMA) and ethidium monoazide (EMA), were evaluated for the detection and quantification of infectious HAV in lettuce wash water. Results showed that PMA combined with 0.5% Triton X-100 (Triton) was the best pretreatment to assess HAV infectivity and completely eliminate…