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Risk Assessment in Shellfish-Borne Outbreaks of Hepatitis A

Risk Assessment in Shellfish-Borne Outbreaks of Hepatitis A Risk Assessment in Shellfish-Borne Outbreaks of Hepatitis A ▿ Rosa M. Pintó , M. Isabel Costafreda and Albert Bosch * Enteric Virus Laboratory, Department of Microbiology and Institute of Nutrition and Food Safety, University of Barcelona, Barcelona, Spain ABSTRACT In the present work, we aimed at determining the relationship between the hepatitis A virus (HAV) numbers in imported frozen coquina clams involved in two hepatitis outbreaks, as well as the risk for human health. Due to HAV unculturability, a standardized TaqMan real-time reverse transcription-PCR controlling the virus/nucleic acid extraction and enzyme efficiencies was employed to figure the exposure dose for clams responsible for hepatitis cases. HAV numbers were then employed to figure the risk of infection based on a dose-response model for echovirus 12. The estimated risk of infection after consumption of lightly cooked clams matched actual attack rates. Our data show that prospective monitoring of bivalve samples may fail to prevent the occurrence of outbreaks, since HAV was detected in 44% of samples directly associated with cases but was undetectable in samples that were randomly collected from the importers and belonged to the same batches. A correlation was nevertheless observed between the prevalence of hepatitis A cases in the harvesting areas and positive HAV isolation in clams, which points to the need to identify and prevent hazards rather than relying on random sampling of finished products to ensure safety. However, when evidence shows that a critical limit of viral contamination has been exceeded in the potential sources of contamination discharging into the shellfish-growing beds, quantitative virological analysis addressing quality assurance and quality control requirements should be performed with the bivalves. This work provides the first evidence of accurate HAV levels in shellfish involved in outbreaks that could be of use for risk assessment purposes. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Applied and Environmental Microbiology American Society For Microbiology

Risk Assessment in Shellfish-Borne Outbreaks of Hepatitis A

Risk Assessment in Shellfish-Borne Outbreaks of Hepatitis A

Applied and Environmental Microbiology , Volume 75 (23): 7350 – Dec 1, 2009

Abstract

Risk Assessment in Shellfish-Borne Outbreaks of Hepatitis A ▿ Rosa M. Pintó , M. Isabel Costafreda and Albert Bosch * Enteric Virus Laboratory, Department of Microbiology and Institute of Nutrition and Food Safety, University of Barcelona, Barcelona, Spain ABSTRACT In the present work, we aimed at determining the relationship between the hepatitis A virus (HAV) numbers in imported frozen coquina clams involved in two hepatitis outbreaks, as well as the risk for human health. Due to HAV unculturability, a standardized TaqMan real-time reverse transcription-PCR controlling the virus/nucleic acid extraction and enzyme efficiencies was employed to figure the exposure dose for clams responsible for hepatitis cases. HAV numbers were then employed to figure the risk of infection based on a dose-response model for echovirus 12. The estimated risk of infection after consumption of lightly cooked clams matched actual attack rates. Our data show that prospective monitoring of bivalve samples may fail to prevent the occurrence of outbreaks, since HAV was detected in 44% of samples directly associated with cases but was undetectable in samples that were randomly collected from the importers and belonged to the same batches. A correlation was nevertheless observed between the prevalence of hepatitis A cases in the harvesting areas and positive HAV isolation in clams, which points to the need to identify and prevent hazards rather than relying on random sampling of finished products to ensure safety. However, when evidence shows that a critical limit of viral contamination has been exceeded in the potential sources of contamination discharging into the shellfish-growing beds, quantitative virological analysis addressing quality assurance and quality control requirements should be performed with the bivalves. This work provides the first evidence of accurate HAV levels in shellfish involved in outbreaks that could be of use for risk assessment purposes.

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References (41)

Publisher
American Society For Microbiology
Copyright
Copyright © 2009 by the American society for Microbiology.
ISSN
0099-2240
eISSN
1098-5336
DOI
10.1128/AEM.01177-09
pmid
19820160
Publisher site
See Article on Publisher Site

Abstract

Risk Assessment in Shellfish-Borne Outbreaks of Hepatitis A ▿ Rosa M. Pintó , M. Isabel Costafreda and Albert Bosch * Enteric Virus Laboratory, Department of Microbiology and Institute of Nutrition and Food Safety, University of Barcelona, Barcelona, Spain ABSTRACT In the present work, we aimed at determining the relationship between the hepatitis A virus (HAV) numbers in imported frozen coquina clams involved in two hepatitis outbreaks, as well as the risk for human health. Due to HAV unculturability, a standardized TaqMan real-time reverse transcription-PCR controlling the virus/nucleic acid extraction and enzyme efficiencies was employed to figure the exposure dose for clams responsible for hepatitis cases. HAV numbers were then employed to figure the risk of infection based on a dose-response model for echovirus 12. The estimated risk of infection after consumption of lightly cooked clams matched actual attack rates. Our data show that prospective monitoring of bivalve samples may fail to prevent the occurrence of outbreaks, since HAV was detected in 44% of samples directly associated with cases but was undetectable in samples that were randomly collected from the importers and belonged to the same batches. A correlation was nevertheless observed between the prevalence of hepatitis A cases in the harvesting areas and positive HAV isolation in clams, which points to the need to identify and prevent hazards rather than relying on random sampling of finished products to ensure safety. However, when evidence shows that a critical limit of viral contamination has been exceeded in the potential sources of contamination discharging into the shellfish-growing beds, quantitative virological analysis addressing quality assurance and quality control requirements should be performed with the bivalves. This work provides the first evidence of accurate HAV levels in shellfish involved in outbreaks that could be of use for risk assessment purposes.

Journal

Applied and Environmental MicrobiologyAmerican Society For Microbiology

Published: Dec 1, 2009

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