Outbreak of Healthcare-Associated Infection and Colonization With Multidrug-ResistantSalmonella entericaSerovar Senftenberg in Florida

Abstract

Background.In July 1999, a rare strain of multidrug-resistantSalmonella entericaserovar Senftenberg was isolated from the sputum of a trauma patient. Over a 6-year period (1999-2005) in northeast Florida, thisSalmonellaserovar spread to 66 other patients in 16 different healthcare facilities as a result of frequent transfers of patients among institutions. To our knowledge, this is the first outbreak of healthcare-associated infection and colonization with a fluoroquinolone-resistant strain of S. Senftenberg in the United States.Objectives.To investigate an outbreak of infection and colonization with an unusual strain of S. Senftenberg and assist with infection control measures.Design.A case series, outbreak investigation, and microbiological study of all samples positive forS.Senftenberg on culture.Setting.Cases ofS.Senftenberg infection and colonization occurred in hospitals and long-term care facilities in 2 counties in northeast Florida.Results.The affected patients were mostly elderly persons with multiple medical conditions. They were frequently transferred between healthcare facilities. ThisSalmonellaserovar was capable of long-term colonization of chronically ill patients. AllS.Senftenberg isolates tested shared a similar pulsed-field gel electrophoresis (PFGE) pattern.Conclusion.A prolonged outbreak of infection and colonization with multidrug-resistantS.Senftenberg was identified in several healthcare facilities throughout the Jacksonville, Florida, area and became established when infection control measures failed. The bacterial agent was capable of long-term colonization in chronically ill patients. Because the dispersal pattern of this strain suggested a breakdown of infection control practices, a multipronged intervention approach was undertaken that included intense education of personnel in the different institutions, interinstitutional cooperation, and transfer paperwork notification.