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Letter
Epidemic Clostridium difficile Strain in Hospital Visitation Dog
Sandra L. Lefebvre,* Luis G. Arroyo,* and J. Scott Weese*
*University of Guelph, Guelph, Ontario, Canada
Suggested citation for this article
To the Editor: Rates of illness and death from Clostridium difficile–associated
disease (CDAD) and reports of CDAD in persons without traditional risk factors
(1) have been increasing. One particular strain of C. difficile has been implicated in outbreaks of CDAD in hospitals in North America and Europe
and appears to be spreading internationally at an alarming rate. This strain
is classified as ribotype 027, toxinotype III, and possesses genes encoding
toxins A, B, and CDT (binary toxin) as well as a deletion in the tcdC gene, which is believed to increase virulence (2).
We report this toxin-variant strain of C. difficile in a healthy, 4-year-old
toy poodle that visits persons in hospitals and long-term care facilities in
Ontario on a weekly basis. C. difficile was isolated from a fecal sample
collected in the summer of 2004 as part of a cross-sectional study evaluating
pathogen carriage by visitation dogs (3). The isolate was subsequently
characterized by ribotyping (4) and by polymerase chain reaction (PCR)
detection of genes that encode production of toxins A and B (5). Toxin
CDT was confirmed by amplifying the portion of the gene (cdtB) that encodes
for the receptor-binding component of the toxin, according to a previously reported
protocol (6). As a result, the isolate was classified as ribotype 027,
toxinotype III (7), and was found to possess all 3 toxin genes. The tcdC gene deletion was also confirmed with PCR (8).
These results indicate that this canine isolate is indistinguishable from the
major strain implicated in outbreaks of highly virulent CDAD around the world.
According to the infection control practitioner at the hospital the dog visited,
CDAD cases were occurring at increased frequency in the facility around the
time the dog’s fecal specimen was collected. However, patient diagnosis was
made solely through fecal toxin testing, and strains were not characterized.
The facility has reported only sporadic cases of CDAD in the past few years.
This is the first report of this human, epidemic strain of C. difficile in a dog. Many C. difficile strains isolated from animals, including
dogs, are indistinguishable from strains associated with disease in humans (9).
To date, no study, including this one, has shown that interspecies transmission
occurs; however, that possibility exists, as is becoming apparent with other
pathogens, such as methicillin-resistant Staphylococcus aureus. The recurrent
exposure of this dog to human healthcare settings suggests that the animal acquired
this strain during visits to the hospital or long-term care facility, either
from the healthcare environment or contaminated hands of human contacts. We
recommend that future studies evaluating the dissemination of this strain and
investigations of the movement of C. difficile into the community consider
the role of animals.
Acknowledgments
We thank Joyce Rousseau for her assistance with culturing and identifying strains
of C. difficile.
This work was supported by the Pet Trust Foundation of the Ontario Veterinary
College.
References
- Centers for Disease Control and Prevention. Severe
Clostridium difficile–associated disease in populations previously at low
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Suggested citation
for this article:
Lefebvre SL, Arroyo LG, Weese JS.
Epidemic Clostridium difficile strain in hospital visitation dog [letter].
Emerg Infect Dis [serial on the Internet]. 2006 Jun [date cited]. Available
from http://www.cdc.gov/ncidod/EID/vol12no06/06-0115.htm
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