An Outbreak of Healthcare-Associated Multidrug-Resistant Salmonella Senftenberg

BACKGROUND/OBJECTIVES: In July 1999, a rare multidrug-resistant Salmonella enterica serovar Senftenberg was isolated from the sputum of a trauma patient. Over a 5-year period, this Salmonella species spread to 54 other patients in several healthcare facilities in Jacksonville, Florida due to frequent transfers of patients among institutions and breakdown of infection control practices. Salmonella Senftenberg isolates were reported between July 1999 and March 2004 from five of the seven hospitals, and eleven long-term care facilities among the approximately fifty in the metropolitan area. This is the first known outbreak of a nosocomial fluoroquinolone-resistant Salmonella Senftenberg in the United States. This descriptive epidemiological analysis will encapsulate the current information known about Salmonella senftenberg infected patients including antibiotic resistance, control/prevention, surveillance, and education. This is the first known outbreak of a nosocomial fluoroquinolone-resistant Salmonella Senftenberg in the United States. METHODS: A medical record abstraction form was developed and data collected on each case included demographics, laboratory information, medical history at diagnosis, and risk factors for a nosocomial infection. The Florida State Laboratory in Jacksonville confirmed the presence of Salmonella senftenberg in isolates by serogrouping and serotyping isolates. DNA fingerprinting or pulse field gel electrophoresis (PFGE) was used to determine if the cases were infected with the same strain. RESULTS: The affected patients were mostly elderly persons with multiple medical conditions. They were frequently transferred between healthcare facilities. This Salmonella species was found capable of long-term colonization of chronically ill patients. All S . Senftenberg isolates tested to date share a similar pulsed-field gel electrophoresis (PFGE) pattern with minor differences. CONCLUSIONS: A prolonged outbreak of multidrug-resistant S. Senftenberg has been identified in several healthcare facilities throughout the Jacksonville area. The bacterial agent was capable of long-term colonization in chronically ill patients. The outbreak continued in hospitals and long term care facilities despite patients being placed in contact precautions. Since the dispersal pattern of this strain suggested a breakdown of infection control practices, a multi-pronged intervention approach was undertaken that included intense education of personnel in the different institutions, inter-institution cooperation, and transfer paperwork notification.