Outbreak Investigation: Potato Salad or Pesticide Poisoning?

Abstract

HISTORY: Sixteen patients from the community of New Sweden presented to Cary Medical Center in April 2003 with symptoms of nausea, vomiting, and diarrhea. All had attended the same church function earlier on the day of presentation. Within 24 hours after the first patient arrived at the facility, the focus of investigations shifted from infectious diseases and food poisoning epidemiology to management of the largest acute arsenic poisoning event in recent medical history. Infection Control (IC) activities are described. PROCESS: Food consumption histories for 72 hours prior to symptoms were taken. Blood cultures were collected, and samples of stool and emesis were submitted for bacteriologic culture. Internal facility notification process was initiated. Incident was reported to the Bureau of Health (BOH) by phone and fax, and after-hours emergency consultation was requested. Rapid onset of symptoms, severity of illness, and numbers of victims prompted report to Northern New England Poison Control Center (NNEPC). Detailed line listing of patients and demographics was prepared for BOH. Church contact person was identified to secure food samples for future testing. Roles and responsibilities were outlined by BOH during conference calls. Centers for Disease Control and Food and Drug Administration offered assistance. Contact persons were identified at all agencies and facilities. IC acted initially as incident commander, and later as liaison for Emergency Room and Laboratory, Medical Examiner's office, NNEPC, Maine State Police, and BOH. Specimen handling was coordinated under chain-of-custody process. Interview data was collated and chart reviews completed. RESULTS: Arsenic was found in coffee samples from the church and in all patient samples. Fifteen of 16 patients survived the poisoning. Survivors were hospitalized at two acute care facilities. All blood cultures were negative after 6 days; Staph aureus was identified in two patients; Bacillus cereus was cultured from a third patient. All survivors received treatment with British Anti Lewisite (BAL) within 36 hours. LESSONS: Rapid response and notification, preliminary investigations, and interagency cooperation led to early identification of causative agent. Emergency preparedness plans and policies must be reviewed to provide for a variety of events. Infection Control Practitioners must be prepared to apply epidemiologic methods in non-infectious settings.