Updating the Listeria Initiative Standardized Questionnaire

Brief Summary
The Listeria Initiative was launched in 2004 to aid in the investigation of listeriosis clusters and outbreaks through the use of epidemiologic data (collected via a questionnaire) and molecular subtyping data.  The questionnaire was designed at the launch of the ListeriaInitiative. Since 2004, novel food vehicles (i.e., celery, whole melons) and possible unrecognized vehicles (e.g., leafy greens), which are not captured by the questionnaire, have been identified through outbreak investigations and regulatory recalls, indicating the need to reconsider the foods assessed on the questionnaire. Additionally, new analyses indicate that the incubation period for non-pregnancy-associated listeriosis may be shorter than previously thought. Therefore, shortening the exposure window assessed for non-pregnancy-associated cases may help focus on food exposures more likely responsible for illness. Recent outbreaks of listeriosis have highlighted the possible role of cross-contamination, in particular of specialty cheeses (which can be cut and repackaged at multiple points during distribution) and of delicatessen meats and salads that are sliced or served at a delicatessen counter.  Current wording on the questionnaire does not adequately assess whether or not cheese was cut and repackaged or if delicatessen meats and salads were sliced or served rather than purchased pre-packaged. Changes in questions and wording will be proposed for feedback. Consideration and discussion of other possible changes to the questionnaire will occur, including ideas from state partners.    Because the ListeriaInitiative compares food consumption histories of patients with cluster-associated illnesses to patients with sporadic illnesses to identify foods possibly associated with a cluster, changes to the questionnaire could affect these comparisons. Pilot studies to assess the effect of changes, especially changes in exposure windows, would be needed and would require planning with state partners. Knowledge about listeriosis has expanded in the last decade, yet the Listeria Initiative questionnaire has not been updated accordingly. Feedback from state partners with regards to the addition of new food items, proposed change to the exposure window, ways to improve clarity, and other ideas will be vital in the process of updating the questionnaire.