Use of Online Consumer Complaint Forms to Enhance Complaint-Based Surveillance for Foodborne Illness Outbreaks in Minnesota

Foodborne illness complaint systems that collect consumer reports of illness following exposure at a food establishment or event are a primary tool for detecting outbreaks of foodborne illness. Approximately, 75% of outbreaks reported to the national Foodborne Disease Outbreak Surveillance System are detected through foodborne illness complaints. The Minnesota Department of Health added an online complaint form to their existing statewide foodborne illness complaint system in 2017. During 2018–2021, online complainants tended to be younger than those who used traditional telephone hotlines (mean age 39 vs 46 years; p value < 0.0001), reported illnesses sooner following onset of symptoms (mean interval 2.9 vs 4.2 days; p value = 0.003), and were more likely to still be ill at the time of the complaint (69% vs 44%; p value < 0.0001). However, online complainants were less likely to have called the suspected establishment to report their illness than those who used traditional telephone hotlines (18% vs 48%; p value < 0.0001). Of the 99 outbreaks identified by the complaint system, 67 (68%) were identified through telephone complaints alone, 20 (20%) through online complaints alone, 11 (11%) using a combination of both, and 1 (1%) through email alone. Norovirus was the most common outbreak etiology identified by both complaint system methods, accounting for 66% of outbreaks identified only via telephone complaints and 80% of outbreaks identified only via online complaints. Due to the COVID-19 pandemic in 2020, there was a 59% reduction in telephone complaint volume compared to 2019. In contrast, online complaints experienced a 25% reduction in volume. In 2021, the online method became the most popular complaint method. Although most outbreaks detected by complaints were reported by telephone complaints alone, adding an online form for complaint reporting increased the number of outbreaks detected.