Temperature-Dependent Survival of Hepatitis A Virus during Storage of Contaminated Onions

Abstract

<jats:title>ABSTRACT</jats:title><jats:p>Pre- or postharvest contamination of green onions by hepatitis A virus (HAV) has been linked to large numbers of food-borne illnesses. Understanding HAV survival in onions would assist in projecting the risk of the disease associated with their consumption. This study defined HAV inactivation rates in contaminated green onions contained in air-permeable, moisture-retaining high-density polyethylene packages that were stored at 3, 10, 14, 20, 21, 22, and 23°C. A protocol was established to recover HAV from whole green onions, with 31% as the average recovery by infectivity assay. Viruses in eluates were primarily analyzed by a 6-well plaque assay on FRhK-4 cells. Eight storage trials, including two trials at 3°C, were conducted, with 3 to 7 onion samples per sampling and 4 to 7 samplings per trial. Linear regression correlation (<jats:italic>r</jats:italic><jats:sup>2</jats:sup>= 0.80 to 0.98) was observed between HAV survival and storage time for each of the 8 trials, held at specific temperatures. Increases in the storage temperature resulted in greater HAV inactivation rates, e.g., a reduction of 0.033 log PFU/day at 3.4 ± 0.3°C versus 0.185 log PFU/day at 23.4 ± 0.7°C. Thus, decimal reduction time (<jats:italic>D</jats:italic>) values of 30, 14, 11, and 5 days, respectively, were obtained for HAV in onions stored at 3, 10, 14, and 23°C. Further regression analysis determined that 1 degree Celsius increase would increase inactivation of HAV by 0.007 log PFU/day in onions (<jats:italic>r</jats:italic><jats:sup>2</jats:sup>= 0.97). The data suggest that natural degradation of HAV in contaminated fresh produce is minimal and that a preventive strategy is critical to produce safety. The results are useful in predicting the risks associated with HAV contamination in fresh produce.</jats:p>

Processing Strategies to Inactivate Hepatitis A Virus in Food Products: A Critical Review

“…On lettuce a slight decrease was observed over time. On artificially inoculated green onions, HAV survived more than 20 d in storage at 3 to 10 °C (Sun and others ), whereas for pepper 17 d were estimated to reduce by 1 log HAV infectivity at 4 °C (Lee and others ). Wang and others () reported the greatest reduction of infectious HAV (2.7 log reduction) on carrots refrigerated overnight, possibly because of the natural antimicrobial properties of carrots.…”

“…Low‐heat dehydration is a common processing method for dehydrating fruits and vegetables which consists of a low‐heat treatment between 40 and 60 °C for 10 to 24 h. Efficacy of low‐heat dehydration of green onions has recently been investigated (Laird and others ; Sun and others ). Heating at 47.8, 55.1, and 62.4 °C for 20 h reduced infectious HAV in green onions by 1, 2, and 3 logs, respectively.…”

Effect of Temperature and Relative Humidity on the Survival of Foodborne Viruses during Food Storage

“…Among the numerous enteric pathogenic viruses, human norovirus (HuNoV) and hepatitis A virus (HAV) are considered to be the most important. In recent reports (4)(5)(6), foodborne outbreaks of HuNoV and HAV were closely associated with fresh produce (e.g., leafy greens and fruits, etc. ), shellfish (oysters and clams, etc.…”

The efficacy of EO waters on inactivating norovirus and hepatitis A virus in the presence of organic matter

“…Epidemiological evidence indicates that human norovirus is the primary pathogen causing acute non-bacterial gastroenteritis and has been listed as the highest-ranking pathogens with respect to the total cost of foodborne illness in the United States (Hoffmann, Batz, & Morris, 2012;Scallan et al, 2011). HAV is a significant cause of viral foodborne illnesses in the US, causing over 85 food and waterborne outbreaks since 1997 (Sun, Laird, & Shieh, 2012). Although there is a recent publication demonstrating human norovirus infection of B cells when assisted by enteric bacteria (Jones et al, 2014), this infectivity model awaits validation and thus human norovirus cannot yet be routinely cultured in the lab.…”