Purpose: The objective was to quantify and compare glove and bare-hand contamination of food and food-contact surfaces, using three glove types and porcine skin sections to mimic bare-hand contact.
Methods: Virus transfer from porcine skins and gloves (yellow latex) to stainless steel (n = 12 each), from porcine skins to gloves (yellow latex, blue latex, nitrile) (n = 9 each), and from contaminated skins and gloves to multiple leaves of iceberg lettuce (n = 6 each) was modeled and quantified using a stool suspension-cocktail of human (GII and GI) and murine norovirus (MNV-1), or MNV-1 alone. Donor surfaces were interfaced with recipient surfaces by applying 1000 g /4.4 cm2 for 10 seconds using a mechanical transfer device. Viruses were eluted from recipient surfaces and recovery was determined following real time RT-qPCR.
Results: Transfer rates (GII, GI, MNV-1) from gloves to stainless steel were higher (53.4%, 61.0% and 56.9%) than from porcine skin to stainless steel (39.3%, 42.4% and 43.0%) (P < 0.05). Transfer rates (GII, GI, MNV-1) from porcine skin to gloves were 38.4%, 33.1% and 34.9% (yellow latex), 50.8%, 51.9% and 41.0% (blue latex) and 35.0%, 35.6% and 29.3% (nitrile), showing that gloves can become contaminated when applied with contaminated hands. After sequentially touching lettuce with contaminated gloves or skins, virus could be detected on the 15th leaf touched following a single contamination event.
Significance: Virus cross-contamination associated with glove use and bare-hand contact is modeled and quantified in this study to help in developing quantitative risk assessment models for human norovirus contamination by food handlers.