Infectious Diseases 2022

Infectious Diseases 2022

Study: >25% of study participants contaminated salad with raw poultry

Journal of Food Protection (2022) 85 (4): 615–625. 2 May, 2022

In a study aimed at assessing the impact of washing poultry on kitchen contamination, researchers found that more than a quarter of study participants contaminated salad with raw poultry – including many study participants who did not wash the poultry.
The study highlights the importance of hand-washing and cleaning and sanitizing the kitchen in order to reduce the risk of foodborne illness when cooking at home.
This study was conducted to test the effectiveness of a consumer poultry washing educational intervention that included video observation of meal preparation with participants who self-reported washing poultry. Treatment group participants received three e-mail messages containing information that the U.S. Department of Agriculture has used on social media sites (video and infographics) related to poultry preparation, including advising against washing chicken. Participants were observed cooking chicken thighs (inoculated with traceable nonpathogenic Escherichia coli strain DH5α) and preparing a salad to determine whether they washed the chicken and the extent of cross-contamination to the salad and areas of the kitchen.
After meal preparation, participants responded to an interview about food handling behaviors, including questions about the intervention for treatment group participants. Three hundred people participated in the study (158 control, 142 treatment). The intervention effectively encouraged participants not to wash chicken before cooking; 93% of treatment group participants but only 39% of control group participants did not wash the chicken (P < 0.0001).
The high levels of E. coli DH5α detected in the sink and on the salad lettuce suggest that microbes transferred to the sink from the chicken, packaging, or contaminated hands are a larger cause for concern than is splashing contaminated chicken fluids onto the counter. Among chicken washers, 26 and 30% of the lettuce from the prepared salad was contaminated for the control and treatment groups, respectively. For nonwashers, 31 and 15% of the lettuce was contaminated for the control and treatment groups, respectively. Hand-facilitated cross-contamination is suspected to be a factor in explaining this resulting lettuce cross-contamination. This study demonstrates the need to change the frame of “don’t wash your poultry” messaging to instead focus on preventing contamination of sinks and continuing to emphasize the importance of hand washing and cleaning and sanitizing surfaces.