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Considerations for Immunocompromised People

(adapted from Angulo FJ, et. al. in J Am Vet Med Assoc 1994;205:1711-1718)

People immunocompromised because of HIV infection, systemic illness, immunosuppressant therapy (for cancer or immune-mediated diseases), or other reasons, are more susceptible to infectious disease than immunocompetent individuals. Some people who work or study in the Veterinary Teaching Hospital and some clients may be immunocompromised. Special consideration must be given to prevention of zoonoses when an animal with an infectious disease interacts with an immunocompromised person. Clients should be educated about the potential risks if a zoonoses is identified in their animal. Acknowledgment of increased susceptibility to infection will allow for recommendations to be made that can minimize the likelihood of transmission. Acknowledgment does NOT have to mean that the client will be urged to destroy the patient.

The following organisms are of potential concern:*

  • Toxoplasma gondii
  • Cryptosporidium spp
  • Salmonella spp
  • Campylobacter spp
  • Giardia spp
  • Rhodococcus equi
  • Bartonella (Rochalimaea) spp
  • Mycobacterium species
  • Bordetella bronchisceptica

*Many factors are considered in making specific recommendations for immunocompromised people, with respect to their pets, including CD4 lymphocyte counts, degree of interaction, and properties of the specific organism. An excellent review of this topic is presented in the article by Angulo cited above. Included in this article are guidelines for the routine health-care of pets belonging to immunocompromised people and the selection of new pets, and the addresses of non-profit groups formed to assist people with HIV with the care of their pets.
Recommendations for routine care of pets belonging to immunocompromised individuals (brief review of general guidelines only; see Angulo, et al. for more complete discussion):

  • Pets should be encouraged to eat only high-quality, fresh commercial pet food and to drink only tap water fit for human consumption. If dietary supplementation cannot be avoided, all meat and eggs should be well cooked and all dairy products should be pasteurized. Consumption of feces, garbage, water from the toilet bowl, or other animals (ie. rodents, birds, etc. through hunting or scavenging) should not be allowed.
  • People should wash their hands after handling pets, especially before eating.
  • People should avoid contact with the pet feces and bird droppings.
  • Cats and dogs should have routine annual veterinary care that includes physical examination, standard vaccinations, and fecal examination for parasites. Bordetella vaccination is recommended only for dogs at high risk for exposure, although avoidance of environments posing high risk is recommended.
  • People should be educated to bring their pet to the veterinarian promptly upon noticing clinical signs.
  • Animals with diarrhea should have fecal cultures performed for Salmonella and Campylobacter, and fecal examinations for Cryptosporidium and Giardia (Zinc sulfate test on 3 specimens). Animals with diarrhea should not remain in contact with immunocompromised people while the problem persists, assessed by clinical signs and sequential fecal analyses.
  • Cat owners should follow guidelines for the prevention of toxoplasmosis as recommended for pregnant women. Cat scratch disease is discussed
  • Immunocompromised people should avoid handling live or dead wild birds.
  • Reptiles are not recommended as pets for immumocompromised people. If kept, gloves should be worn when cleaning the cage or handling the animal. Raw meat and egg products should not be fed.
  • Gloves should be worn when handling aquarium fish or cleaning aquaria.
  • Contact with young farm animals should be avoided, especially if they are exhibiting diarrhea.