Puppies: a source of multidrug-resistant pathogens
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A recent outbreak showed that puppies can be a source of Campylobacter infections in humans — including multidrug-resistant infections — and underlined that clinicians should consider this exposure in their patients.
Writing in MMWR, Martha P. Montgomery, MD, an Epidemic Intelligence Service officer with the CDC, and colleagues summarized a yearslong and multistate outbreak of multidrug-resistant Campylobacter infections linked to the commercial dog industry.
“This evidence, combined with the prolonged nature of the outbreak and the potential for puppy commingling, indicates a potential for continued transmission of multidrug-resistant Campylobacter industrywide, including at breeders, distributors, transporters, and stores, and ultimately in customers’ homes,” they wrote.
Each year in the United States, Campylobacter causes approximately 1.3 million diarrheal illnesses. Montgomery and colleagues investigated an outbreak of Campylobacter that sickened 118 people, including 29 pet store employees, between Jan. 5, 2016, and Feb. 4 of this year. There were 26 hospitalizations but no deaths in the outbreak.
According to the report, the CDC was alerted in August 2017 to six Campylobacter jejuni infections that the Florida Department of Health linked to a national pet store chain based in Ohio. During the investigation, state and local health departments used a standardized, supplemental questionnaire to collect dog exposure information from people infected with Campylobacter.
The CDC defined a confirmed case as any patient with campylobacteriosis symptom onset between Jan. 1, 2016, and Feb. 28, 2018; with a clinical isolate closely related to the outbreak strain; or with other laboratory evidence of infection and a history of working in, visiting or having contact with a puppy from a pet store.
Of the 118 reported cases, 12 had unknown dog exposures. Of the 106 patients for whom dog exposure questions were answered, 99% (n = 105) reported dog exposure and 95% (n = 101) reported contact with a pet store puppy. Furthermore, eight individuals reported contact with puppies from five pet store companies that were not the source of the initial outbreak. Montgomery and colleagues said that this indicates that puppies were infected before reaching pet stores.
Investigators conducted traceback investigations that included collecting records, transport information and microchip identification numbers for puppies owned by infected persons and those sampled in stores. They did not identify a single infection source among breeders, distributors or transporters. Rather, they said that the commingling of puppies from different breeders at distributors, during transport and in stores could drive Campylobacter transmission.
Investigators also collected antibiotic administration records from 20 pet stores across Kentucky, Ohio, Pennsylvania and Wisconsin for 149 puppies. Among them, 95% (n = 142) received at least one antibiotic before arriving or while at the store and 94% (n = 134) had available treatment indications, Montgomery and colleagues reported. According to the report, 55% (n = 78) of the treated puppies received antibiotics for prophylaxis only and 38% (n = 54) received antibiotics for prophylaxis and treatment, whereas 1% (n = 2) received antibiotics for treatment only.
Metronidazole, sulfadimethoxine, doxycycline and azithromycin comprised 81% of all the antibiotics administered, the authors reported. Broad-spectrum antibiotics such as tetracyclines, quinolones, aminoglycosides and chloramphenicol also were used.
“The investigation of this outbreak revealed widespread administration of multiple antibiotic classes, including all classes to which the outbreak Campylobacter strains were resistant,” Montgomery and colleagues wrote. “Adherence to antibiotic stewardship practices in these settings might reduce the selection of highly drug-resistant Campylobacter. Implementation of antibiotic stewardship principles and practices in the commercial dog industry is needed.” – by Marley Ghizzone
Disclosure: The authors report no relevant financial disclosures.