A detection dog to identify patients with Clostridium difficile infection during a hospital outbreak

Abstract

Objectives: Early and rapid identification of Clostridium difficile infections (CDI) is important to prevent transmission. In this study we assessed the diagnostic accuracy of a trained detection dog for detecting CDI cases on hospital wards in an outbreak setting.

Methods: During a CDI outbreak in a large Dutch university hospital, we screened affected hospital wards repeatedly with a trained detection dog. The dog's response was compared to the clinical diagnosis, supported by laboratory results.

Results: During a total of 9 hospital visits, the dog performed 651 screenings involving 371 participants. The dog correctly identified 12 out of 14 CDI cases [sensitivity 86% (95% confidence interval (CI): 56-97%)] and 346 out of 357 CDI negative participants [specificity of 97% (95% CI: 94-98%)]. Interestingly, of the 11 CDI negative participants that were 'falsely' indicated by the dog as positive, 2 (18%) did actually developed CDI during the 3 months of follow-up after the detection period; compared to only 12 of the 346 participants (3.5%) that the dog identified as C. difficile negative (p = 0.06).

Conclusion: A trained detection dog can accurately detect CDI in hospitalized patients during an outbreak. A (repeated) positive dog response is a strong indication of a CDI episode coming, be it the next day or possibly up to a month.

Keywords: Clostridium difficile; Detection dog; Outbreak containment; Scent detection; Sensitivity and specificity.