Marking the fourth year in a row for such illnesses, federal officials are investigating an outbreak of multidrug-resistant Campylobacter infections traced to contact with pet store puppies.

At least 30 people across 13 states are infected with the outbreak strain of Campylobacter jejuni, according to an announcement today from the Centers for Disease Control and Prevention. It is the same strain that sickened people in an outbreak that lasted from 2016 through 2018.

Of 26 patients with available information in the current outbreak, four have been so sick they had to be admitted to hospitals. Overall the outbreak victims range in age from 8 months to 70 years old. The patients became ill between January and November this year.

Additional infections are likely to be confirmed and reported because of the lag time between when symptoms begin and when testing and confirmation take place. Only then are public health officials notified. A single, common supplier of puppies has not been identified. The investigation is ongoing.

Outbreak investigators have been able to interview 24 of the sick people so far. Of those, 88 percent — or 21 — reported contact with a puppy before becoming sick. Fifteen people reported contact with a puppy from a pet store and 12 of those were linked to the national pet store chain Petland. Five of the 24 people interviewed were Petland employees.

“Laboratory evidence indicates that bacteria from ill people in this outbreak are closely related genetically to bacteria from ill people in the 2016–2018 outbreak of multidrug-resistant Campylobacter infections linked to pet store puppies,” the CDC reported. The outbreak sickened 113 people in 17 states.

Inadequate hygiene practices such as not washing hands in a timely and proper manner can easily result in the spread of the bacteria. Foods and food contact surfaces such as kitchen counters and utensils can be cross-contaminated after touching an infected animal, according to the CDC.

So far evidence indicates that puppies purchased from pet stores are the likely source of this outbreak. 

“Many of the cases (patients) had contact with puppies or were employees at pet stores, including Petland,” according to the CDC.

The outbreak strain of Campylobacter jejuni is resistant to multiple antibiotics that are used as frontline medications to fight the infections caused by the bacterium. Whole-genome sequencing (WGS), also known as DNA fingerprinting, has shown the outbreak strain is resistant to tetracycline, ciprofloxacin, nalidixic acid, azithromycin, erythromycin, clindamycin, telithromycin, and gentamicin.

In addition to the 30 outbreak patients, investigators have identified another eight sick people who have had contact with Petland puppies and “who had a diagnostic test showing they were infected with Campylobacter bacteria,” according to the CDC. “However, the CDC did not include these people in the outbreak case count because no bacterial samples were available for WGS.”

The CDC and state public health officials are reminding consumers to wash their hands thoroughly after contact with pets and to supervise children so that they properly wash their hands immediately after contact with any animals.

Also, people who buy animals from pet stores are urged to take them to a veterinarian within a week for a health checkup. Some animals and people infected with Campylobacter do not develop symptoms, but they can still infect others.

According to the CDC, many people with Campylobacter infections develop diarrhea that is often bloody, along with possible fever, and stomach cramps. Symptoms usually begin two to five days after exposure.  2 to 5 days after being exposed to the bacteria. The illness usually lasts about a week and many people recover without antibiotic treatment.

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