Hand hygiene interventions are critical for reducing farmworker hand contamination and preventing the spread of produce-associated illness. Hand hygiene effectiveness may be produce-commodity specific, which could influence implementation strategies. This study's goal was to determine if produce commodity influences the ability of handwashing with soap and water or Two-Step ABHS interventions to reduce soil and bacteria on farmworker hands. Farmworkers (n = 326) harvested produce for 30-90 minutes before engaging in handwashing (cantaloupe, jalapeño, and tomato), Two-Step ABHS (jalapeño and cantaloupe), or no hand hygiene. Hands were rinsed to measure amounts of soil (absorbance at 600 nm) and indicator bacteria (coliforms, Enterococccus, generic Escherichia coli, and Bacteroidales universal [AllBac] and human-specific [BFD] 16S rDNA markers). Without hand hygiene, bacterial concentrations (0.88 to 5.1 log10 CFU/hand) on hands significantly differed by the produce commodity harvested. Moderate significant correlations (ρ = -0.41 to 0.56) between soil load and bacterial concentrations were observed. There were significant produce-commodity specific differences in the ability of handwashing and Two-Step ABHS interventions to reduce soil (P < 0.0001), coliforms (P = 0.002), and Enterococcus (P = 0.003), but not the Bacteroidales markers AllBac (P = 0.4) or BFD (P = 0.3). Contamination was more difficult to remove from cantaloupe farmworker hands. Overall, we found that a Two-Step ABHS intervention was similar to handwashing with soap and water at reducing bacteria on farmworker hands. In sum, produce commodity type should be considered when developing hand hygiene interventions on farms.IMPORTANCE This study demonstrated that the type of produce commodity handled influences the ability of handwashing with soap and water or a Two-Step alcohol-based hand sanitizer (ABHS) intervention to reduce soil and bacterial hand contamination. Handwashing with soap and water, as recommended by the FDA's Produce Safety Rule, when tested in three agricultural environments, does not always reduce bacterial loads. Consistent with past results, we found that the Two-Step ABHS method performed similarly to handwashing with soap and water, but also does not always reduce bacterial loads in these contexts. Given the ease of use of the Two-Step ABHS method, which may increase compliance, the Two-Step ABHS method should be further evaluated and possibly considered for implementation in the agricultural environment. Taken together, this study provides important information on hand hygiene effectiveness in three agricultural contexts.
Both Handwashing and Alcohol-Based Hand Sanitizer Reduce Soil and Microbial Contamination on Farmworker Hands During Harvest - But Produce Type Matters.