Health Department Use of Social Media to Identify Foodborne Illness — Chicago, Illinois, 2013–2014

Discussion

Foodborne illness is a serious and underreported public health problem with high health and financial costs. Emerging evidence on the effectiveness of social media for foodborne illness surveillance suggests mining tweets and restaurant reviews might aid in identifying and taking action on localized foodborne illness complaints that would otherwise go unreported.^[5,8,9] Using a new surveillance and response strategy, the CDPH identified and responded to 270 tweets about foodborne illness over 10 months in the Chicago area; 193 Chicago FoodBorne forms reporting foodborne illness were filed during this period. The majority of the 193 forms did not indicate that medical treatment was sought and so would likely not have been included in the usual surveillance numbers nor prompted inspections by the health department. Twenty-one of the reported restaurants failed inspection and were closed; 33 additional restaurants passed with conditions. Rates of critical and serious violations and failing inspections prompted by FoodBorne Chicago complaints were similar to those from inspections in response to other complaints during the same period.

The findings in this report are subject to at least two limitations. First, the Twitter application programming interface does not allow precise geographic filtering, and FoodBorne Chicago only used the keyword "food poisoning" to identify tweets. Second, it was not possible to determine how many of the 193 web form complaints were from persons directed to the form via Twitter. Project staff members were able to link 30 tweets directly to a corresponding complaint when report submitters clicked on the link in the "reply tweet" to access and complete the form. However, the number of persons who tweeted, did not click the link, and later accessed the Foodborne Chicago web form is unknown.

CDPH food inspectors and supervisors initially were concerned that use of Twitter would overburden them with increased inspections. However, by understanding the process better and seeing the success in finding violations, CDPH staff members have become supportive of obtaining potential foodborne illness information via Twitter.

CDPH and its partners are actively working to improve and disseminate the FoodBorne Chicago program. In an effort to increase the effectiveness of staff replies to complaints via Twitter, CDPH held four focus groups and plans an online survey. In addition, CDPH is currently working with the Boston Public Health Commission and the New York City Department of Health and Mental Hygiene to adapt FoodBorne Chicago for use in those two cities. FoodBorne Chicago also is available as open-source software on GitHub, an online host for sharing computer code with the public or a private audience.^†

^†Additional information is available at https://github.com/smartchicago/foodborne.

Morbidity and Mortality Weekly Report. 2014;63(32):681-685. © 2014  Centers for Disease Control and Prevention (CDC)