Purpose: Our goal was to compare the effect of two soap-based and two ABHS-based hygiene interventions on the microbial load and soil (defined as matter removed from hands during sampling) on farmworker hands after produce harvesting.
Methods: One hundred eighty-one farmworkers, after produce harvesting, were randomly assigned to soap-based groups (antimicrobial or pumice soap), ABHS-based groups (label-use or two-step), or no-hygiene control. We measured each intervention’s ability to reduce the microbial load (coliforms, E. coli, and Enterococcus) and soil (A600nm of hand rinsate). P < 0.05 was considered significant.
Results: With no hand hygiene, farmworkers’ hands were heavily soiled (geomean A600nm = 0.46) and contaminated with high coliform (geomean 3.4 log CFU/hand) and Enterococcus (geomean 5.3 log CFU/hand) levels after 1 - 2 hours of harvesting tomatoes. Farmworkers’ hands across all intervention groups had significantly less Enterococcus and E. coli, but not coliforms, compared to those in the control group. No significant differences in microbial loads were observed across any soap- or ABHS-based groups. The two-step ABHS intervention had lower levels of coliforms and Enterococcus than the pumice soap and label-use ABHS interventions, and was the only intervention to have significantly fewer samples with E. coli than the control group. Farmworkers’ hands across all intervention groups had significantly less soil compared to those in the control group; soap-based interventions were better at removing soil from hands than ABHS-based interventions.
Significance: ABHS was equally effective as recommended practices (handwashing with soap) at reducing indicator organisms on farmworkers’ hands, and was more effective when used with the two-step ABHS technique. Based on these results, ABHS can be viewed as an effective hand hygiene solution, even on soiled hands.