During a multidrug-resistant Campylobacter outbreak, 142 puppies were identified as receiving 1 or more antibiotic courses before arriving or while at the store.
Prudent use of antibiotics is recommended to all health care providers to reduce the incidences of drug-resistant infections. Now, the US Centers for Disease Control and Prevention (CDC) is reminding the public that these practices should also be carried over to caring for pets.
From January 1, 2016, through February 28, 2018, there was a multistate outbreak of multidrug-resistant Campylobacter jejuni linked to puppy exposure. The outbreak affected 29 pet stores in 18 states and prompted a multistate investigation.
A total of 118 ill individuals—including 29 pet store employees—were reported from 18 states. Demographic information was available for 115 individuals who ranged in age from <1 year to 85 years, with a median age of 26 years. Seventy-four of 115 (63%) cases were reported in females. Treatment information was available for 107 individuals and indicated that 26 (24%) of the ill were hospitalized.
Investigators used a questionnaire to collect information about dog exposure from individuals with Campylobacter. From a total of 106 ill individuals, 105 (99%) reported being exposed to a dog and 101 (95%) had contact with a pet store puppy. Pet store contact was reported in puppies in 6 different pet stores indicating that the puppies became ill prior to reaching the pet store.
In light of the questionnaire results, health officials in multiple states visited pet stores to collect puppy fecal samples, antibiotic records, and traceback information.
Among 149 puppies with available information, 142 (95%) received 1 or more antibiotic courses before arriving or while at the store; four antibiotics—metronidazole, sulfadimethoxine, doxycycline, and azithromycin—accounted for 81% of all antibiotics that were administered. The high rate raises concern that antibiotic use might have led to the development of resistance in ill humans.
Stool specimens were submitted to public laboratories and culture and whole genome sequence typing was performed to compare genetic relatedness.
Campylobacter jejuni isolates were obtained for 51 humans and 23 puppies. Outbreak isolates from 45 individuals and 11 puppies were grouped into 3 distinct clades as a result of whole-genome multilocus sequence typing.
Isolates from 10 humans and 8 puppies from all 3 clades were selected to be tested for antibiotic susceptibility. All 18 isolates were resistant to azithromycin, ciprofloxacin, clindamycin, erythromycin, nalidixic acid, telithromycin, and tetracycline. Additionally, 16 isolates were resistant to gentramicin, and 4 were resistant to florfenicol.
“Highly visible outbreaks like this highlight that antibiotic use in animals can and do result in resistant bacterial infections in humans," said Jason Gallagher, PharmD, clinical professor, Temple University School of Pharmacy, editor-in-chief of Contagion®. "It also demonstrates that these infections are not limited to the farm, where most of the attention on animal antibiotic use is focused.”
This is not the first outbreak of Campylobacter to be associated with dogs; however, these outbreaks are typically not as large and have never been multidrug-resistant.
It is important that pet store employees and pet owners should practice handwashing, separating human areas from animal areas and using personal protective equipment when cleaning pet cages, according to the report.
Clinicians should consider that Campylobacter infections can be transmitted from puppies to humans and consider a Campylobacter infection if a patient presents with symptoms including diarrhea and vomiting.