Marnie, a public health nurse (PHN) is employed by the Warren Public Health Unit. She was contacted by a local church after several church members became sick following its annual picnic. Of the 200 people who attended the picnic, 100 were ill with diarrhea, nausea, and vomiting. Ten people required emergency medical treatment or hospitalization. Incubation periods ranged from 1 1/2 to 30 hours, with a mean of 6 hours and a median of 3 1/2 hours. The duration of the illness ranged from 1 to 80 hours, with a mean of 30 hours and a median of 15 hours. The annual church picnic was a potluck lunch buffet. The menu included macaroni casserole (brought by the Carusos), turkey with gravy and stuffing (brought by the Smiths), potato salad (brought by the Changs), green bean casserole (brought by the Champs), chili (brought by the Turners), homemade bread (brought by Grand-Maman Rivest), chocolate cake (brought by the Bushes), and cookies (brought by the Beckmans). Marnie interviewed the church members who were ill and discovered that three specific food items were clearly associated with the illness: turkey, gravy, and stuffing. Marnie interviewed the Smiths, who brought the turkey, gravy, and stuffing to the picnic. A review of their food-handling procedures showed that after the turkey had been cooked, it had been left out for 4 hours to come to room temperaturea time and temperature sufficient for bacterial growth and toxin production. Furthermore, the same dishes were used for cooking the turkey and the other foods. Marnie educated the Smiths on proper foodhandling practices, emphasizing handwashing, proper cooling and preserving methods, and better sanitation of dishes. Marnie also offered a similar educational session to the entire church congregation.