Pets in the Bedroom — Move Over Rover!

Abstract & Commentary

By Mary-Louise Scully, MD, Director, Travel and Tropical Medicine Center, Sansum Clinic, Santa Barbara, CA. Dr. Scully reports no financial relationships relevant to this field of study.This article originally appeared in the June 2011 issue of Travel Medicine Advisor. At that time it was peer reviewed by Lin Chen, MD, Assistant Clinical Professor, Harvard Medical School; Director, Travel Medicine Center, Mt. Auburn Hospital, Cambridge, MA. Dr. Chen reports no financial relationship to this field of study.

Synopsis: The increasingly close and almost intimate relationships with our pets can lead to increased numbers of cases and the emergence of zoonotic diseases, including human plague (Yersinia pestis).

Source: Chomel BB, Sun B. Zoonoses in the bedroom. Emer Infect Dis 2011;17:167-172.

The numbers of households with pets are increasing in many countries across the world. In addition, data obtained from media sources note a trend in the percentage of these pets sleeping in, or on, the owner's bed. To address whether this behavior is associated with the acquisition of zoonotic disease(s), the authors searched PubMed for peer-reviewed publications that demonstrated disease likely to have been acquired by sleeping with, sharing a bed with, kissing, or being licked by pets.

The results encompassed bacterial, parasitic, and viral associated zoonoses. The bacterial zoonoses included those with known animal associations such as Yersinia pestis (plague), Bartonella species (cat-scratch disease), Pasturella species, and Capnocytophaga camimorsus. In the case of a plague outbreak, one patient had the onset of his illness the morning after noting bites from his flea-infested cat who had shared his bed.1 Another case-control study of plague survivors found 44% of survivors vs 10% of controls reported sleeping in the same bed with a pet dog.2 Although Bartonella infections are often associated with a scratch of a cat that harbors Bartonella henselae-infected fleas, a 9-year-old girl from Taiwan with multi-organ (hepatic, splenic, and renal) disease from Bartonella, became ill after sleeping with her cat at night.3 In a study of Pasturella multicida meningitis, 27 (87%) of 31 infants exposed to animals had been exposed in various ways to oropharyngeal animal secretions through either licking or sniffing.4 In addition, Pasturella wound infections have been reported when the animals had been observed licking the wounds prior to onset of illness.5

C. camimorsus is a gram-negative bacillus that is known for its presentation of a purpura fulminans-like sepsis, especially in asplenic, alcoholic, or steroid-dependant patients. Several cases in the literature exist for which the portal of entry was felt to be a direct result of a pet licking an ulcer or abraded skin of the patient. For example, a patient with chronic ulcerous eczema of the legs whose dog used to lick his legs, died of septic shock and renal failure caused by C. camimorsus.6

Commentary

These are just some of the highlighted cases discussed in this article. I recently saw a patient with a post-surgical septic olecranon bursitis caused by Staphylococcus intermedius. The patient admitted his dog may have licked the wound or provided saliva exposure during their playful nightly wrestling on the floor. The most recent reference I found to include data on this evolving topic is from the Center for Food Security & Public Health from Iowa State University from January 2011 — an MRSA article with more than 180 references!7 We are very likely seeing the tip of the iceberg on this emerging issue.

In May 2011, shortly after the Chomel article was published, the CDC published two cases of human plague in MMWR from Oregon in 2010. These were the first cases reported from Oregon since 1995 and they were the only plague cases reported in the United States in 2010. The patients, ages 17 and 42, lived in the same household with a dog that was later found to be seropositive for Y. pestis by passive hemagglutination-inhibition assay. Although both patients had clinical illness compatible with human plague, including bilateral inguinal buboes, fever, and hypotension, plague was not suspected initially. One patient's blood culture specimen was later identified as positive, and the other patient had a positive serology. One of the patients admitted sleeping in the same bed with the dog during the 2 weeks prior to the onset of illness. Fortunately, both patients recovered after empiric therapy with doxycycline.

Pets are known to provide company and assuage the loneliness of countless human beings worldwide and as such, they are often considered "part of the family." Although transmission of zoonotic infections from pets is rare, it would seem prudent to ensure our pets are properly de-wormed and free of fleas, and defer from sharing the same bed with them to prevent serious and potentially fatal infections.

References

1. Von Reyn CF, et al. Epidemiologic and clinical features of an outbreak of human bubonic plague in New Mexico. J Infect Dis 1977;136:489-494.

2. Gould LH, et al. Dog-associated risk factors for human plague. Zoonoses Public Health 2008;55:448-454.

3. Liao HM, et al. Systemic cat scratch disease. J Formos Med Assoc 2006;105:674-679.

4. Kobayaa H, et al. Pasturella multicida meningitis in newborns after incidental animal exposure. Pediatr Infect Dis J 2009;28:928-929.

5. Chun ML, et al. Postoperative wound infection with Pasturella multicida from a pet cat. Am J Obstet Gynecol 2003;188:1115-1116.

6. Dudley MH, et al. Fatal capnocytophaga infection associated with splenectomy. J Forensic Sci 2006;51: 664-666.

7. Methicillin Resistant Staphylococcus aureus (MRSA). Center for Food Security & Public Health from Iowa State University, January 2011. Available at: www.cfsph.iastate.edu/Factsheets/pdfs/mrsa.pdf. Accessed May 15, 2011.