Lessons to be Learned from an Outbreak of Foodborne Listeriosis, Austria 2009-2010

摘要

From June 2009 until February 2010, an outbreak of invasive listeriosis affected 25 persons in Austria, 8 in Germany and I in the Czech Republic.The source of this outbreak with 8 fatalities was initially identified based solely on epidemiological findings. Grocery receipts of purchases from 7 patients were collected prospectively during 3 weeks after discharge from hospital and compared for matches.This generated a hypothesis tested by a case control study, which revealed Austrian 'QuargeF cheese asthe source of infection.At least two patients had consumed the contaminated product after it was withdrawn from the market. Risk communication with the public is of utmost importance, especially if hard-to-reach elderly are involved. Of 63 food samplesof the product analyzed officially, 20 were positive for L monocytogenes and 10 samples harbored > 100 CFU/g (maximum 92,000 CFU/g). A leftover specimen, stored in a patient's refrigerator,yielded 2,100,000 CFU/g of L monocytogenes indistinguishable fromthe patient's isolate. L monocytogenes was first documented in the plant in a sample of smear fluid in May 2009, which temporarily coincided with major construction work. European legislation requires 'QuargeP not to exceed 100 CFU/g when products are placed on the market during their shelf life. A routine sample from a market had already shown 400 CFU/g in July 2009.We feel that a general zero tolerance policy would not have provided additional safety in this outbreak situation.