Zoonosis screening in Spanish immunocompromised children and their pets

Introduction: Although pets provide several social-emotional benefits for children, the risk of zoonosis must be considered among immunocompromised individuals.

Methods: A prospective study was conducted in a tertiary hospital including immunocompromised patients younger than 20 years owning dogs and/or cats. Colonization and/or infection was evaluated by stool studies, bacterial swabs, blood polymerase chain reaction and serological studies in both patients and their pets, to evaluate potential zoonotic transmission occurrence.

Results: We included 74 patients and their 92 pets (63 dogs, 29 cats). Up to 44.6% of the patients and 31.5% of the pets had at least 1 positive result. Up to 18.4% of pets' fecal samples were positive (bacteria, parasites or hepatitis E virus). No helminths were observed despite the high frequency of incorrect intestinal deworming practices. Among children, gastrointestinal microorganisms were found in 37.3% (primarily Clostridium difficile). Colonization by Staphylococcus pseudintermedius was common among pets (8.0%) but not among children (0.0%). No shared colonization between owners and pets was observed, except in one case (Blastocystis in both patient and pet feces). Among patients, serologies were positive for Strongyloides stercoralis (14.8%), Toxocara canis (3.2%), Bartonella henselae (19.1%) and hepatitis E (5.6%). Serology was positive for Rickettsia spp. (22.6%) and Babesia spp. (6.5%) in dogs and for Leishmania spp. (14.3%) and Toxoplasma spp. (14.3%) in cats.

Conclusion: Exposure to zoonotic agents was detected in both patients and pets; however, shared colonization events were almost nonexistent. In our cohort, dogs and cats do not appear to entail high zoonosis transmission risk for immunocompromised patients.