A study published recently in the Journal of Hospital Infection (Lefebvre & Weese, 2009) looked at contamination of the haircoat of animals used in hospital visitation programs. In the study, Dr. Lefebvre petted animals that were going into a hospital and we cultured her hands.  Then when the dogs finished their visits she petting them again and we re-cultured her hands.  We tested for MRSA and Clostridium difficile, two important causes of hospital-associated infections. The goal was to see if the dogs’ coats could become contaminated, presumably by patients’ hands, during regular visits. The dogs’ paws were also tested before and after to see what they picked up walking around the hospital.

After being in the hospital, one dog (4%) was found to have C. difficile on its feet. The strain that was recovered (ribottype 027/NAP1) is a strain of great concern, being it has caused outbreaks of illness internationally. The fact that there was C. difficile on the dog’s paws, which was presumably picked up from the floor in the hospital, isn’t exactly surprising. It shows that contact with dogs’ feet (e.g. shaking a paw) could be a source of exposure to people in hospitals, and at home, and that dogs could be exposed to C. difficile after hospital visits by licking their paws. We previously demonstrated in another study that visitation dogs are at high risk for picking up C. difficile during visits.

The more important aspect of the study was what ended up on Dr. Lefebvre’s hands after petting the dogs – a very common type of contact with dogs in hospitals and at home. She picked up MRSA from the coat of one dog (4% of dogs overall) after it had been in the hospital. The dog was not an MRSA carrier, and it did not have contact with anyone known to be carrying MRSA during its visit. Presumably, there was someone in the hospital that was an unknown carrier. If MRSA was on the person’s hands, they could have transfered the MRSA to the dog’s coat. The important part is that this MRSA was then able to spread to someone else’s hands (Dr. Lefebvre’s, in this case). This is a potential route of transmission of MRSA to patients during hospital visitations, and to other people these dogs might encounter outside of hospitals. The same thing could presumably happen with other infectious agents, including bugs like norovirus and influenza. These can’t infect dogs, but dogs could potentially be short-term vectors of these viruses and spread them around a hospital.

The good thing about all this is that some basic guidelines can greatly reduce the risk of transmission:

• Patients should wash their hands  or use an alcohol-based hand sanitizer before  (to reduce the risk of depositing something on the pet’s coat) and after (to reduce the risk of picking something up from the pet’s coat) touching a pet.
• Pets should be kept off beds unless a disposal/washable barrier (e.g. drape, towel) is kept between the pet and the bed sheets, to prevent dirty feet from infecting the patient’s living space/clothes/sheets.
• People should not “shake-a-paw” with pets in hospitals.

All these precautions can be taken without compromising the benefits of hospital pet visitations. More details about guidelines for hospital visitation aniamls can be found in an earlier post. More information about Clostridium difficile and MRSA can be found on the Worms & Germs Resources page.