Quantitative modeling of school cafeteria share tables predicts reduced food waste and manageable norovirus-related food safety risk

Abstract

Share tables (ST) allow students to share unwanted food items with other students in school cafeterias, making them a possible method to reduce food waste and insecurity. This study assesses potential food safety risks and food security benefits of a ST system, to assess if future work on STs is warranted. But food safety concerns from stakeholders hinder ST implementation. A quantitative microbial risk assessment was developed to (i) predict food safety risk (specifically norovirus transmission via apples) associated with the implementation of STs in school cafeterias, (ii) identify effective mitigation strategies to prevent illness, and (iii) screen for potential food security benefits. To estimate the impact and efficacy of mitigation strategies, illness prevalence was compared between 13 different what-if scenarios. Results show that STs modestly increase the mean illness prevalence from 1.5% (2.5–97.5th percentile: 0.52–2.7%) to 1.6% (2.5–97.5th percentile: 0.67–2.8%), a 6.8% increase in illness prevalence. Mitigation strategies that focus on managing incoming norovirus loads are predicted to be most effective. Specifically, efficient student handwashing and hand sanitizing reduced the illness prevalence in a ST system to 43.6 and 41.9%, respectively. Other mitigation strategies, such as washing and wrapping fruit, are predicted to be less effective. Other results show that STs have the potential to reduce food waste of fruit by 54% (2.5–97.5th percentile: 44–61%), increase consumption by 21% (2.5–97.5th percentile: 32–11%), and decrease item utilization by 6.9% (2.5–97.5th percentile: 1.5–13%), compared to the baseline traditional cafeteria scenario. This study suggests that share tables have potential to safely reduce food waste. While share tables are predicted to slightly increase the illness prevalence, that risk is manageable by applying mitigation strategies.