com. Of the 13,262 businesses included in the dataset, 5842 (43.9%) were classified as foodservice businesses. The data included all reviews from 2005 to 2012. The volume of yearly reviews and reports of foodborne illness increased Decitabine cell line linearly from 2005 to 2011, with the majority of data

observed between 2009 and 2012 (see Fig. 1). 538 (9.2%) foodservices had at least one alleged foodborne illness report resulting in 760 reports with mentions of foodborne diseases and terms commonly associated with foodborne illness (such as diarrhea, vomiting, etc.). Each review containing at least one of the foodborne illness-related terms was carefully read to extract information on date of illness, foods consumed, business reviewed and number of ill individuals. Most individuals

mentioned being sick recently, but only 130 (17.1%) indicated the actual date of illness. 12 (1.58%) individuals with an alleged illness mentioned visiting a doctor or being hospitalized, and 80 (10.5%) reports indicated that more than one individual experienced illness. Since each review includes the restaurant information, the data can be visualized and also used by public health authorities for further investigation. We also studied the characteristics of reviewers who submitted reports of foodborne illness to identify any “super-reporters”. The highest number of reports by a single individual was four and the median number HDAC inhibitor of reports was one. Since most reviewers (99.5%) had only one or two reports of alleged illness, we did not need to perform the bias analysis outlined in the Methods section or eliminate any reviewers from the analysis. We disaggregated the data by state and found that California (n = 319), Massachusetts (n = 109) and New York (n = 57) had the most illness reports. Since the data

were generated based on colleges, those in sparsely populated regions might have fewer restaurants and therefore fewer reviews. We observed six clusters of more than two illness reports implicating the same business between 2007 and 2012, however, in most cases, reports were observed in different years. The six restaurants were located in California (four), Georgia (one) and Massachusetts (one). Per Yelp, one of the restaurants has closed. Restaurant inspection reports (see Table A.3) for four next of the restaurants suggested at least one food violation in the last four years. These violations included: contaminated equipment, improper holding temperature, and cleanliness of food and nonfood contact surfaces. 557 (73.3%) Yelp foodborne illness reports and 1574 (47.4%) CDC FOOD outbreak reports included the foods consumed prior to illness. Of the 1574 CDC outbreak reports, 383 (24.3%) identified the contaminated ingredient. Foods were categorized based on the CDC’s convention of categorizing and grouping implicated foods (see Fig. 2) (Painter et al., 2009 and Painter et al., 2013).