Methodologic challenges and lessons learned through conducting a hospital-based Salmonella Javiana case-control study.

Our analyses implicated fruit cups in an outbreak of salmonellosis in 2 hospitals. Other methodologic challenges included selection of controls among sick patients, heterogeneity of food exposures, reliance on food orders rather than foods consumed, and retention of food history records. Understanding and anticipating these challenges through changes to policies and operational procedures is critical for conducting efficient and effective case-control studies in the hospital setting.