Co-Authors:
Marijke Decuir, Kirk Smith, Carlota Medus, Craig Hedberg

Advisor:
Craig Hedberg

Keywords:
Foodborne Illness, Complaint-Based Surveillance

Abstract

BACKGROUND:

Foodborne illness complaint systems 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 (MDH) added an online complaint form to their existing statewide foodborne illness complaint system in 2017. We investigated how this expansion of complaint reporting methods influenced MDH’s ability to detect foodborne illness outbreaks.  

METHODS:

We queried the MDH complaint database for complaint records that were received by the MDH complaint-based surveillance system from 1/1/2018 through 12/31/2021. Comparisons were made using Chi-square tests and odd ratios where appropriate. Analysis was conducted using SAS 9.4. Means and medians were compared using T-tests and Wilcoxon-Mann-Whitney tests, respectively.

RESULTS:

Online complainants tended to be younger than telephone complainants (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 (p-value <0.0001). However, online complainants were less likely to have called the suspected establishment to report their illness (p-value <0.0001). Of the 98 outbreaks identified by the complaint system, 67 were identified through telephone complaints alone, 20 through online complaints alone, and 11 using a combination of both. 

CONCLUSIONS:

Adding online complaint methods broadened the demographic profile of complainants and enhanced the effectiveness of the complaint system to detect outbreaks of foodborne illness. Continual evaluation of public health practice methods is necessary to improve surveillance and prevent illness.