What to know
Interviewing people as soon as possible about where and what they ate in the days or weeks before they got sick is critical. This can prevent more people from getting sick by quickly generating hypotheses during outbreak investigations, identifying people in high-risk settings, and providing information about how to stop the spread of disease. FoodCORE centers, such as South Carolina, dedicate resources to ensure timely and complete interviews.
South Carolina Swiftly Stops an STEC Outbreak at a School
On April 7, 2022, a FoodCORE Regional Response Coordinator (RRC) at the South Carolina Department of Health and Environmental Control (SCDHEC) identified two people infected with Shiga toxin-producing Escherichia coli (STEC) who attended the same school and reported travel to Costa Rica. Through interviews, the RRC worked quickly to gather information on symptom history, travel history, water and food sources, and animal contact. The RRC confirmed that the people traveled to Costa Rica for a school research trip between March 24 and April 1, 2022, with nearly 140 other students and chaperones. It was at this point that an outbreak investigation was initiated. On April 11, 2022, during the outbreak monitoring and follow up, a third person with STEC infection was identified and linked to the same trip. In total, five people were linked to this outbreak.
From the interviews, the RRC learned that the first three infected people that were identified had abdominal cramps, and two of the three had diarrhea. Common food sources across the three were rice, beans, chicken, and pineapple. All three participated in water-based activities, including swimming and white-water rafting, and one infected person had contact with a sea turtle during the trip to Costa Rica.
As part of this investigation, the South Carolina Public Health Laboratory (PHL) confirmed that two of the peoples' STEC infections were closely related by whole genome sequencing (WGS), a laboratory technique that provides detailed genetic information about the germs that make people sick. This suggested that those two people likely got sick from the same contaminated source. Without laboratory data to support a genetic link in the other three cases, strong epidemiologic data suggested that they were also linked to the outbreak.
Combining the epidemiological and laboratory information, the RRC swiftly took action to stop the outbreak and protect others from getting sick. The RRC shared educational materials, including cleaning guidance, with the school nurse and all people who were exposed. In accordance with South Carolina law, the school nurse was given information on the exclusion of sick students and staff from school and activities to prevent the spread of disease.
Having a dedicated team of FoodCORE RRCs at SCDHEC was critical in interviewing sick people as soon as possible so that they might better remember details of events and exposures before their illnesses started. In addition, these RRCs worked closely with the foodborne epidemiologist and scientists at the PHL to arrange for the appropriate submission of clinical samples for further testing. Through their close partnership, the SCDHEC multi-disciplinary team rapidly and efficiently identified an STEC outbreak in a school linked to travel to Costa Rica, collected data to support the investigation, and provided education to stop the outbreak and prevent more illnesses.