Onset of diarrhea and pyrexia and time to detection of Salmonella enterica subsp enterica in feces in experimental studies of cattle, horses, goats, and sheep after infection per os

Abstract

Objective-To determine time to first detection of Salmonella organisms in feces of animals after experimental infection PO and times to onset of diarrhea and pyrexia to evaluate a common method for identifying nosocomial infections on the basis of time of admission and onset of clinical signs (ie, the 3-day criterion). Design-Meta-analysis. Sample Population-Cattle, horses, goats, and sheep experimentally infected PO with Salmonella enterica subsp enterica. Procedures-Online databases were searched for published reports describing results of experimental infection of cattle, horses, goats, and sheep PO with salmonellae. Time to detection of organisms in feces as well as to onset of diarrhea and pyrexia was noted. Analysis of covariance was used to examine relationships among these variables, host species and age, and Salmonella serovar and magnitude of infecting dose. Results-Forty-three studies met the criteria for inclusion. Time to detection of salmonellae in feces ranged from 0.5 to 4 days. Times to onset of diarrhea and pyrexia ranged from 0.33 to 11 days and from 0.27 to 5 days, respectively. Time to onset of diarrhea was related to host age and Salmonella serovar. No other associations were identified. Conclusions and Clinical Relevance-Time to detection of salmonellae in feces is unreliable for identifying hospital-acquired infections; a 3-day criterion will misidentify hospital- versus community-acquired infections. Relying on clinical indices such as times to onset of diarrhea and pyrexia to trigger fecal sampling for detection of Salmonella infection will increase the risk of environmental contamination and nosocomial spread because animals may begin shedding organisms in feces several days prior.