Dogs, zoonoses and immunosuppression

Abstract

Dogs are the source of a wide range of zoonotic infections that pose a significant threat to human health. This is particularly the case for immunocompromised people, although there are few robust studies that determine immunosuppression as a risk factor for transmission of zoonoses from dogs to humans. An increasing proportion of human society is immunodeficient, principally through the advent of HIV infection and through more people, particularly the expanding elderly group, being subjected to immunosuppressive agents. This is happening at a time when more such people are capitalizing on the acknowledged benefits of dog ownership, making for a potentially dangerous mix. Enteric pathogens (for example, Salmonella, Campylobacter and Cryptosporidium species, that may be canine derived) are a frequent risk to the health of immunocompromised persons. Veterinarians and physicians can be criticised for not communicating with each other, and for not providing adequate risk assessment to pet owners. There is scope for voluntary groups to provide information and support for the immunosuppressed who wish to keep their dogs. Key recommendations are to maintain a clean personal environment and intact mucocutaneous barriers. Public health professionals could help rectify the current communications gap between veterinary and medical staff and so facilitate in the appropriate management of dog-owning immunocompromised people.

Possible Transmission ofCryptosporidium canisamong Children and a Dog in a Household

“…It is been suggested for some time that dogs can be a significant source of human cryptosporidiosis (1,5,16). This suggestion, however, has been largely based on the observation of direct transmission of Cryptosporidium parvum from calves to humans and the erroneous suggestion that C. parvum is responsible for cryptosporidiosis in all mammals.…”

Important emerging bacterial zoonotic infections affecting the immunocompromised

“…Dog should be confined whenever possible and walked only on a leash to prevent hunting, coprophagia, and garbage eating. Immunocompromised patients who wish to acquire a new pet should avoid puppies or kittens, as they are more susceptible to enteric infection [82]. The Centers for Disease Control and Prevention's Healthy Pets, Healthy People website recommends avoiding dogs and cats < 6 months old, as they are more likely to carry zoonotic diseases [27].…”

Prevalence of virulence and cytolethal distending toxin (CDT) genes in thermophilic Campylobacter spp. from dogs and humans in Gyeongnam and Busan, Korea

“…into their feces. Therefore, contact with the pets has been shown to be a risk factor for Campylobacter infections in humans and actual transmission has been demonstrated [15,29].…”