Comparison of detection methods for Salmonella enterica shedding among reptilian patients at a veterinary teaching hospital. (January 2020)

• Record Type: Journal Article
• Authors: Fagre, Anna C.; Pabilonia, Kristy L.; Johnston, Matthew S.; Morley, Paul S.; Burgess, Brandy A.
• Is Part Of: Journal of veterinary diagnostic investigation. Volume 32:Number 1(2020:Jan.)
• Page Start: 118
• Page End: 123
• Publication Date: 2020-01
• Subjects: detection testing -- infection control -- public health -- reptiles -- Salmonella; Veterinary medicine -- Diagnosis -- Periodicals; 636.0896075
• DOI: 10.1177/1040638719886542
• Languages: English
• ISSNs: 1040-6387

Abstract

In the United States, ~1.4 million sporadic human Salmonella enterica infections occur annually, with an estimated 6% attributable to reptile exposure. Detection of Salmonella in reptiles can be challenging given the limitations among detection methods. We evaluated sampling and detection methods for S. enterica in a cross-sectional study of reptilian patients ( n = 45) over the course of 13 mo. Two sampling methods (cloacal swabs, electrostatic cloth body-feet samples) and 3 detection methods (enriched culture, lateral flow immunoassay [LFI], real-time PCR) were compared using McNemar and Fisher exact tests. Results varied by species, sample type, and detection method. In total, 14 of 45 (33%) patients were positive by culture, 10 of 45 (22%), and/or 13 of 45 (29%) by rtPCR. Among rtPCR-positive results, cloacal swabs (12 of 45 [27%]) resulted in a higher detection than body-feet wipes (4 of 45 [9%]; p = 0.01). Among culture-positive results, shedding was most commonly detected after additional incubation at room temperature when testing cloacal swabs (9 of 45 [20%]). However, there was significant disagreement between sampling methods (cloacal vs. body-feet; p = 0.03). No samples were positive by LFI. In general, cloacal swabs yielded the highest test-positive rates, irrespective of testing method. Our study highlights the importance of using detection methods optimized for the sample being tested.