Pet Ownership by Immune Suppressed People

Zoonotic diseases are defined as being common to, shared by, or naturally transmitted between humans and other vertebrate animals. Humans are infected with zoonotic agents from direct contact with the infected pet, contact via contaminated food or water, from shared vectors, and from the shared environment. Direct contact with animal feces (enteric zoonoses), respiratory secretions, urogenital secretions, or infected skin and exudates, as well as bites and scratches can result in human infections.

Vectors

Some zoonotic agents are transmitted between animals and man by shared vectors like fleas, ticks, or mosquitoes. Rickettsia rickettsii (ticks), Ehrlichia spp. (ticks), Borrelia burgdorferi (ticks), Rickettsia felis (fleas), Bartonella spp. (fleas, ticks), Dirofilaria immitis (mosquitoes), Dipylidium caninum (mosquitoes), and West Nile virus (mosquitoes) are examples of vector borne zoonoses. The pet brings the vector of the organism into the environment resulting in exposure of the human. Bartonella spp. are notable examples as some species like B. henselae survive in flea feces for days. Flea and tick control should always be maintained on our client’s animals and infested animals that are seen in the clinic should be treated immediately.

Zoonotic Agents

Some zoonotic agents including Histoplasma capsulatum, Coccidioides immitis, Blastomyces dermatitidis, Cryptococcus neoformans, and Aspergillus spp do not usually infect humans from direct with the infected pet but are acquired from the same environmental source.

Immunodeficient Humans

Most of the agents discussed in this lecture can infect and cause disease in anyone, but disease is generally more prevalent or more severe in those that are immunodeficient. Humans with AIDS are discussed most frequently, but there are many more immunodeficient individuals including the very old, the very young, and those receiving chemotherapy for immune-mediated diseases, organ transplantation, or neoplasia. Humans are unlikely to contract zoonotic diseases from contact with their pets and so in most cases do not need to relinquish their animals. The Centers for Disease Control of the United States online publication, Preventing Infections from Pets; A Guide for People with HIV Infection, states ‘You do not have to give up your pet’1 . The American Association of Feline Practictioner’s Zoonoses Guidelines states ‘All human or animal care providers should provide accurate information to pet owners concerning the risks and benefits of pet ownership so that an informed decision about acquiring and keeping pets can be made’. [...]