Microbial Sharing between Pediatric Patients and Therapy Animals during Hospital Animal-Assisted Intervention Programs

Background: Microbial sharing between humans and animals has been demonstrated in a variety of settings. However, the extent of microbial sharing that occurs within the healthcare setting during animal-assisted intervention programs, a validated and valuable part of holistic patient wellness, is unknown. Understanding microbial transmission between patients and therapy animals can provide important insights into potential health benefits for patients, in addition to addressing concerns regarding potential pathogen transmission that limits program utilization. This study evaluated the potential for microbial sharing between pediatric patients and therapy dogs, and tested whether patient-dog contact level and a dog decolonization protocol modified this sharing. Methods and Results: Patients, therapy animals, and the hospital environment were sampled before and after every group therapy session and samples underwent 16S rRNA sequencing to characterize microbial communities. Both patients and animals experienced changes in the relative abundance and overall diversity of their nasal microbiome, suggesting that exchange of microorganisms had occurred. Increased contact was associated with greater sharing between patients and therapy animals, as well as between patients. A topical chlorhexidine-based dog decolonization intervention was associated with decreased microbial sharing between therapy dogs and patients, particularly from the removal of rarer microbiota from the dog, but did not significantly affect sharing between patients. Conclusion: These data suggest that the therapy animal is both a potential source of and a vehicle for the transfer of microorganisms to patients but not necessarily the only source. The relative contribution of other potential sources (e.g., other patients, the hospital environment) should be further explored to determine their relative importance.