New hepatitis A virus findings from S. Butot and co-researchers published
2009 JUL 13 - (NewsRx.com) -- "Several hepatitis A virus (HAV) and human norovirus (HuNoV) outbreaks due to consumption of contaminated berries and vegetables have recently been reported. Model experiments were performed to determine the effectiveness of freeze-drying, freeze-drying combined with heating, and steam blanching for inactivation of enteric viruses that might be present on the surface of berries and herbs," scientists writing in the journal Applied and Environmental Microbiology report. "Inactivation of HAV and inactivation of feline calicivirus, a surrogate for HuNoV, were assessed by viral culturing and quantitative reverse transcription PCR (RT-PCR), whereas HuNoV survival was determined only by quantitative RT-PCR. While freeze-drying barely reduced (<1.3 log(10) units) the amount of HAV RNA detected in frozen produce, a greater decline in HAV infectivity was observed. The resistance of HuNoV genogroup I (GI) to freeze-drying was significantly higher than that of HuNoV GII on berries. Addition of a terminal dry heat treatment at 120 degrees C after freeze-drying enhanced virus inactivation by at least 2 log(10) units, except for HuNoV GII. The results suggest that steam blanching at 95 degrees C for 2.5 min effectively inactivated infectious enteric viruses if they were present in herbs," wrote S. Butot and colleagues. The researchers concluded: "Our results provide data for adjusting food processing technologies if viral contamination of raw materials is suspected.." Butot and colleagues published their study in Applied and Environmental Microbiology (Inactivation of Enteric Viruses in Minimally Processed Berries and Herbs. Applied and Environmental Microbiology, 2009;75(12):4155-4161). Additional information can be obtained by contacting G. Sanchez, CSIC, Institute Agroquim & Tecnol Alimentos, Apartado Correos 73, Valencia 46100, Spain. The publisher of the journal Applied and Environmental Microbiology can be contacted at: American Society Microbiology, 1752 N St. NW, Washington, DC 20036-2904, USA. Keywords: Spain, Valencia, Caliciviridae, Gastroenterology, HAV, Hepatitis A Virus, Hepatology, Infectious Disease, Viral, Virology. This article was prepared by Hepatitis Weekly editors from staff and other reports. Copyright 2009, Hepatitis Weekly via NewsRx.com.
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