Hepatitis A virus attachment to agri-food surfaces using immunological, virological and thermodynamic assays

Aims: This study was designed to investigate the ability of hepatitis A virus (HAV) to attach to various food contact surfaces. Methods and Results: HAV attachment was demonstrated after elution of attached viruses from solid surfaces by an immunofluorescent method using anti-HAV-specific antibodies and confocal microscopy. Attachment and survival of HAV on stainless steel, copper, polythene and polyvinyl chloride (PVC) at 20 and 4degreesC after 2 and 4 h were quantified by plaque assay. HAV was shown to attach almost instantaneously to all four surfaces tested. Attachment of HAV depended on initial viral concentration and was slightly greater at 4degreesC. The total surface energy (gamma(TOT)), nonpolar Lifshitz-Van der Waals (gamma(LW)) and polar short range (gamma(SR)) hydrogen-bonding components for HAV and each surface as well as total free energy of the system were determined by contact angle measurements using an extended Young equation [Young (1805) Philosophical Transactions of The Royal Society (London) 95, 65-87). The calculation of these parameters predicted the favourable conditions for attachment of HAV to all four surfaces tested. Conclusion: HAV particles attach to stainless steel, copper, polythene and PVC at 20 and 4degreesC and the total free energy of the interaction is optimal for this attachment. Significance and Impact of the Study: Comprehension of viral attachment to the solid surfaces will permit to successfully disinfect these surfaces and to establish a better surveillance programme for control of viral food-borne illnesses.