Following an investigation, pet store puppies have been identified as the source of an antibiotic-resistant infection, which affected over a hundred people across the United States. 

The report was published by the Centers for Disease Control and Prevention (CDC) on Sept. 21.

Campylobacteriosis, a sporadic bacterial infection, is estimated to cause 1.3 million illnesses in the country each year. The outbreak, which started in January 2016 and continued until February 2018, was found to have affected 118 individuals in 18 states during the two-year period.

After the patients were interviewed, a common thread was identified when 99 percent of them reported direct contact with a pet store puppy, which may have spread the bacteria. While the six pet stores were not identified by name, they were reportedly primarily located in Ohio and Florida.

The infection can lead to symptoms such as fever, abdominal pain, bloody diarrhea, headaches, nausea, and vomiting. But in most cases, recovery takes less than a week without any specific treatment besides rest and rehydration.

Major complications are not expected unless the patient is an infant, over the age of 65, or has a weakened immune system. According to the World Health Organization, antimicrobial treatment is only recommended in invasive cases or to eliminate the carrier state.

"This outbreak demonstrates that puppies can be a source of multidrug-resistant Campylobacter infections in humans, warranting a closer look at antimicrobial use in the commercial dog industry," the report stated.

Out of 149 puppies who were investigated, 142 were given one or more courses of antibiotics, more for the sake of prevention rather than to treat an existing condition. This is believed to have been a form of "overtreatment," not an uncommon occurrence among animal breeders, which likely contributed to the strains developing drug resistance.

Matthew Wellington, antibiotics program director for U.S. Public Interest Research Group, emphasized how antibiotics should never be used to compensate for poor hygiene practices, be it with animals or human beings. 

"This is one of the clearest examples I’ve seen where resistant bacteria are originating in animals from antibiotic overuse, and they’re passing directly to people and spreading rapidly," he said. "So I think this is one of those situations where it’s incredibly clear that this is a problem we need to solve."

Good hygiene is the key precaution for people who interact with dogs and puppies, especially the ones from pet stores. This would include washing your hands after touching the animals or cleaning up their waste.

But the agency pointed out one should not worry too much about being around man's best friend as the likelihood of infection from "puppy exposure" was not too high. Most campylobacteriosis infections tend to occur due to consumption of contaminated water, raw or undercooked poultry, unpasteurized dairy, etc.