Hypothesis generating interviews were undertaken with seven of the earliest cases reported by the emergency rooms and the Student Health Center; all of the cases had onset of illness on March 10. Four were male and three were female; all but one was a freshman. Two students were psychology majors; one each was majoring in English and animal husbandry. Three students were undecided about their major.

The students were from five different residential halls and all reported eating most of their meals at the university's main cafeteria. During the past week, all but one student had eaten food from the deli bar; two had eaten food from the salad bar, and three from the grill. Seven-day food histories revealed no particular food item that was common to all or most of the students.

Except for the psychology majors, none of the other students shared any classes; only one student had a roommate with a similar illness. Five students belonged to a sorority or a fraternity. Three students had attended an all school mixer on March 6, the Friday before the outbreak began; two students went to an all night science fiction film festival at one of the dorms on March 7. Students reported attendance at no other special events; most had been studying for midterm exams for most of the weekend.

1: Using information available to you at this point, state your leading hypothesis(es) on the pathogen, mode of transmission, source of the outbreak, and period of interest.

2: What actions would you take? Who would you question? Where might you look for the origin of the pathogen?