The public was notified through media and local bulletins, and at a community meeting, that those who had attended the event and were ill should contact the health department for E. coli testing. Over the next two weeks, 27 people were identified and confirmed as cases associated with the outbreak. Of those who were infected, 5 were hospitalized and one 6-year-old child developed HUS.
During the course of their investigation, health officials interviewed attendees and food handlers, inspected food and water, and conducted a case-control study. Through statistical analysis, tri-tip was implicated as the source of the E. coli O157:H7. Subsequent testing of leftover tri-tip revealed the presence of E. coli O157:H7. Further testing also confirmed that each of the ill individuals, as well as the left-over tri-tip, shared a genetically identical strain of E. coli O157:H7.