The student health center at a nearby college reported yesterday that they had seen a large number of cases of what students are calling “a stomach flu.” Students are reporting to the health center with the complaint that within the last 24 hours they have developed vomiting and diarrhea. Although student health sees this sort of illness fairly often, this one is distinctive in both its rapid onset and the large number of students involved.
In order to find the source of the epidemic, health workers have been asking ill students and their roommates to fill out a short questionnaire to identify anything that is common to the ill students and not to healthy ones. So far, it has been noted that the majority of the students reside in one of two dormitories and generally eat their meals at a cafeteria located inside one of those dorms. Additionally, a large number (62%) of these students all reported that they had gone on a recent geology field trip to collect specimens at a nearby quarry. So far, all patients are male.
There does not appear to be a pattern of the roommates of sick patients falling ill, although it may be too soon to tell.

Day one: afternoon

You have received blood and urine samples from one of the case patients. Additionally, this patient’s stool has been cultured and the plate has been sent over for you.

Day two: morning

Another 12 students reported to the health center last night. Meanwhile, the first wave of patients appears to be recovering. In addition to the students, two part-time faculty members have fallen ill. As a result of the two ill faculty members, a common link between the ill students has been noticed. Because the questionnaire failed to ask about extracurricular activities, it was not noticed until today, when two assistant football coaches fell ill that all of the sick patients are members of the football team or their support staff (statisticians, etc.).

Day two: afternoon

A few more cases have been discovered, but the outbreak appears to be subsiding. Outside of the football team, no new cases have been discovered on campus. The illness appears to clear itself within about 48 hours, although 4 students have had to be hospitalized for severe dehydration.
Health department officials are now examining the locker room for a potential source of the outbreak. However, the maintenance staff cleans the entire room with a mild bleach solution each evening after the team practices, so it is not likely that anything that could have caused this outbreak will still be alive in that environment. Additionally, the cafeteria has been asked to provide samples of any foods used to prepare a team breakfast that was served prior to a game one day before the outbreak began.
The team recently played against a team from Trenton State College that had to travel several hours by bus to get to the game. One student recalled that a number of the other team’s players appeared to be suffering from motion sickness when they arrived.

Day three: morning

The outbreak appears to have subsided. In total 24 players on the team and 2 assistant coaches got sick. Additionally, 45 sick players were found at the visiting school. The visiting team had been given boxed lunches containing tuna salad sandwiches for the ride to the game. Although none the remains of these boxed lunches can be obtained, at least one player recalled that his sandwich tasted “a little off.”
Investigators have been dispatched to the catering company where the lunches were prepared and have found unsanitary conditions in the kitchen, including the use of a single sink for washing dishes, vegetables and hands. The investigators have sent you serum and stool samples from all of the workers at this catering company. You also have samples from several players on the visiting football team.
No treatment was given, beyond rehydration for the four hospitalized players. All patients recovered within about 48 hours of first falling ill.