*Contributed equally to the production of the manuscript.
Outbreak of Salmonellosis Caused by Salmonella enterica Serovar Newport MDR-AmpC in a Large Animal Veterinary Teaching Hospital
Article first published online: 24 JUN 2010
Copyright © 2010 by the American College of Veterinary Internal Medicine
Journal of Veterinary Internal Medicine
Volume 24, Issue 5, pages 1138–1146, September/October 2010
How to Cite
Dallap Schaer, B.L., Aceto, H. and Rankin, S.C. (2010), Outbreak of Salmonellosis Caused by Salmonella enterica Serovar Newport MDR-AmpC in a Large Animal Veterinary Teaching Hospital. Journal of Veterinary Internal Medicine, 24: 1138–1146. doi: 10.1111/j.1939-1676.2010.0546.x
This work was presented in part at the 11th International Symposium on Veterinary Epidemiology and Economics, Cairns, Australia, August 2006.
- Issue published online: 2 SEP 2010
- Article first published online: 24 JUN 2010
- Submitted September 9, 2009; Revised April 16, 2010; Accepted April 28, 2010.
- Infection control program;
Background: Nosocomial salmonellosis is an important problem for large animal veterinary teaching hospitals (VTHs).
Objective: To describe failure of an Infection Control Program (ICP) that resulted in an outbreak of salmonellosis caused by Salmonella Newport multidrug resistant (MDR)-AmpC at a large animal VTH.
Animals: Sixty-one animals identified with the outbreak strain of Salmonella.
Methods: Retrospective study: Data collected included signalment, presenting complaint, duration of hospitalization, discharge status, and financial information. Phenotypic and genotypic characterization was performed on Salmonella isolates.
Results: The outbreak occurred despite an existing ICP; the ICP was reviewed and weaknesses identified. Routine patient surveillance was not performed before or during the outbreak; fecal sampling was triggered only by a patient algorithm based on clinical signs. Sixty-one animals were infected with the outbreak strain of S. Newport, and the majority were horses (n = 54). Case fatality rate was 36.1%. S. Newport isolates demonstrated high genetic similarity (Dice ≥ 0.96), and all had the MDR-AmpC phenotype. Environmental persistence of the organism necessitated complete hospital closure, extensive decontamination, and remediation of the facility. A paradigm shift in the relevance of biosecurity in a VTH and the establishment of a stringent ICP were integral components of successful hospital reopening.
Conclusions and Clinical Importance: An ineffective ICP resulted in a nosocomial outbreak caused by a MDR S. Newport in a VTH. Closure of a VTH affected all missions of the institution and had substantial financial impact (US$4.12 million).