An outbreak of salmonellosis among horses at a veterinary teaching hospital

Abstract

Between May 1996 and February 1997, 27 horses and a veterinary student at a veterinary teaching hospital developed apparent nosocomial Salmonella Typhimurium infection. The source of the multiple-drug resistant Salmonella Typhimurium was a neonatal foal admitted for treatment of septicemia. A high infection rate (approx 13% of hospitalized horses) coupled with a high case fatality rate (44%) for the initial 18 horses affected led to a decision to close the hospital for extensive cleaning and disinfection. Despite this effort and modification of hospital policies for infection control, 9 additional horses developed nosocomial Salmonella Typhimurium infection during the 6 months after the hospital reopened. Polymerase chain reaction testing of environmental samples was useful in identifying a potential reservoir of the organism in drains in the isolation facility. Coupled with clinical data, comparison of antimicrobial resistance patterns of Salmonella Typhimurium isolates provided a rapid initial means to support or refute nosocomial infection. Although minor changes in the genome of these isolates developed over the course of the outbreak, pulsed-field gel electrophoresis testing further supported that salmonellosis was nosocomial in all 27 horses.

Salmonella entericaSerovar Oranienburg Outbreak in a Veterinary Medical Teaching Hospital with Evidence of Nosocomial and On-Farm Transmission

“…Hospitalized animals are likely to be at elevated risk of salmonellosis because of concurrent illness, stress associated with transport and a change in housing, and factors related to their care, including surgery and the administration of various drugs. Several outbreaks of salmonellosis in veterinary medical teaching hospitals have been reported, primarily among horses (Hartmann et al 1996, Tillotson et al 1997, Schott et al 2001, Ward et al 2005, Dallap Schaer et al 2010, Steneroden et al 2010. Outbreaks can have a number of serious consequences, including zoonotic transmission, morbidity and mortality among patients, and economic costs associated with heightened biosecurity efforts (Tillotson et al 1997, Schott et al 2001.…”

“…Several outbreaks of salmonellosis in veterinary medical teaching hospitals have been reported, primarily among horses (Hartmann et al 1996, Tillotson et al 1997, Schott et al 2001, Ward et al 2005, Dallap Schaer et al 2010, Steneroden et al 2010. Outbreaks can have a number of serious consequences, including zoonotic transmission, morbidity and mortality among patients, and economic costs associated with heightened biosecurity efforts (Tillotson et al 1997, Schott et al 2001. For outbreaks that are severe enough to warrant temporary hospital closure, there are additional losses of financial revenue and teaching caseload (Dallap Schaer et al 2010).…”

Genetic regulation of host responses to Salmonella infection in mice

“…Approximately 1.4 million cases (sporadic form or outbreaks) per year of salmonellosis occur in the United States alone. 2 In veterinary medicine, Salmonella spp are also significant pathogens associated with economic and productivity losses, food contamination, 3,4 and outbreaks among horses hospitalized in large animal clinics 5 or on breeding farm facilities. 6 The contribution of the host genetic background to the risk of infection and disease severity has been evidenced in humans by studies documenting racial differences in disease susceptibility, a higher concordance in monozygotic vs dizygotic twins and, more recently, using large-scale family-based genome scans and association studies.…”

Identification of Two Phylogenetically Related Organisms from Feces by PCR for Detection ofSalmonellaspp

“…Salmonella-infected animals in a veterinary hospital, dairy, or other animal populations must be quickly identified so that they can be isolated from other animals and spread of infection can be controlled (12,13,15,20,22,29,30). Outbreaks of Salmonella infections have occurred in large animals in several veterinary teaching hospitals and have resulted in significant expense and, in some cases, temporary closure of the hospital (15,18,23,25,29,30). A more rapid method for detection of Salmonella spp.…”