Barriers to Trace-back in a Salad-associated EHEC Outbreak, Sweden, June 2013

摘要: In June-July 2013, six counties notified the Swedish Institute for Communicable Disease Control of enterohaemorrhagic E.coli (EHEC) infections among attendees at a hotel in Dalarna, Sweden. An outbreak control team investigated to identify source and implement measures. We included individuals who attended between June 19th-25th cohort. asked them about animal contact, swimming, consumption food items during this time using questionnaire. A confirmed case was an EHEC O157:H7 strain positive individual developed abdominal pain or diarrhoea 20th-July 2nd. described time, place person, calculated risk ratios (RR) 95% confidence intervals (CI). kitchen, tested traced back implicated items. 172 responded. identified 19 cases (Median age: 17 years, 64% female) with symptom onset 22nd-27th. Eating green salad on 20th associated illness (RR:3.7;CI:1.3-11). The kitchen mixed salads without records destroyed leftovers immediately. Hence we could not conduct trace-back obtain microbiological confirmation. Green contaminated before entering likely source. recommended early collaboration agencies better restaurant facilitate future investigations.