UC Davis

Background

Both reusable and single-use gloves can be employed during hand harvesting of lettuce and leafy greens. The impact of glove type on survival and transfer of Escherichia coli was evaluated using agar or lettuce in a laboratory setting and during simulated lettuce harvesting in the field.

Results

Textured and smooth reusable latex and smooth disposable latex gloves inoculated with E. coli were sequentially touched to 10 or 20 agar plates or 20 lettuce leaves (n = 6; laboratory) or used to sequentially harvest 20 heads of lettuce (n = 6; field). E. coli was recovered by enrichment from significantly fewer leaves (46%; 55 of 120) or heads (26%; 31 of 120) of lettuce when inoculated reusable textured gloves were used compared with disposable gloves (leaves: 98%; 118 of 120, or heads: 74%; 89 of 120). In contrast, when a single head of lettuce was the point source for glove contamination, there was no significant difference in the number of E. coli-positive lettuce heads harvested with reusable textured (71%; 85 of 120) or disposable gloves (75%; 90 of 120). In either field-contamination scenario, at the 20th head of lettuce harvested with a single glove (final sample point), E. coli was recovered from one to five of six lettuce heads across experimental trials.

Conclusion

Contamination of a glove from a single point source can lead to subsequent contamination of multiple heads of lettuce during hand harvesting, showing the importance of policies to manage hand hygiene and glove use for harvest crews.