METHODS: Laboratory-confirmed cyclosporiasis cases were contacted for interview with the Cyclosporiasis National Hypothesis-Generating Questionnaire. Outbreak cases were persons who reported eating at a Fulton County, Georgia restaurant in the 14 days before illness onset. Data analysis was performed in EpiInfo to describe outbreak cases, and to compare reported exposures between cases and 2006-7 FoodNet Population Survey control interviews conducted from May through August. Additionally, Fulton County Environmental Health conducted a restaurant investigation, and the Georgia Rapid Response Team (RRT) conducted an environmental assessment and traceback investigation.
RESULTS: Fifteen cases were identified. All cases were adults with median age 46 years (range 30-71). Ten (67%) cases were female. 427 Georgia adult Population Survey controls were included in the analysis. The median age of controls was 55 years (range 18-87), and 283 (66%) were female. Cases reported consuming various food items at Restaurant A. Meal dates ranged from June 14 to June 21, and onsets ranged from June 21 to June 28. The odds of eating salsa (p<0.001), cilantro (p<0.001), avocado (p<0.001), scallions or green onions (p<0.01), lemon or lime (p<0.01), tomatoes (p<0.05), and mesclun lettuce (p<0.05) among outbreak cases were significantly higher than the odds of consuming each of those items among controls. Item-specific attack rate was greatest for salsa (93%), and ranged from 23%-86% for other items. Environmental Health observed that cilantro was the only fresh imported salsa ingredient. The Georgia RRT, in conjunction with the U.S. Food and Drug Administration (FDA), identified that Restaurant A received cilantro from Puebla, Mexico, a region with farms associated with previous Cyclospora outbreaks and an ongoing national outbreak. The joint investigation implicated imported cilantro from Puebla, Mexico as the outbreak vehicle.
CONCLUSIONS: Although multiple fresh produce items were epidemiologically associated with illness among case-patients, vehicle identification also required ingredient-specific information, origin country, and produce traceback. Coordination between state and local Epidemiology, county Environmental Health, state Department of Agriculture, and the FDA was essential in this investigation. This collaborative investigation highlights the importance of multi-agency investigations for foodborne illness outbreaks.