A multi-state bacteria outbreak that made dozens of people sick across the country is being linked to a national pet store chain. According to the Centers for Disease Control and Prevention, puppies sold at Petland are believed to be behind the outbreak.

The CDC reports 39 people from seven different states have become ill due to a bacteria called Campylobacter. The states are Florida, Kansas, Missouri, Ohio, Pennsylvania, Tennessee and Wisconsin.

The first case was reported on Sept. 15, 2016, and the latest earlier this month on Sept. 1. There were nine people hospitalized. No deaths have been reported.

The federal agency said 27 of the 39 people who got sick either purchased a puppy at Petland, or visited or live in a home with a puppy sold from the pet store. Among the 39 people who became ill 12 of them were Petland employees.

"The CDC has not identified any failures of Petland's operating system that would lead to any Campylobacter infection," Petland said in a statement sent to 5 On Your Side.

“Petland reinforces proper hand sanitization before and after playing with any of our puppies with the many sanitation stations in each store and has strict kennel sanitation procedures and protocols put in place by consulting veterinarians.”

The company said it is fully cooperating with the CDC and said they were told to "continue to do what we are already doing".

According to the CDC, Campylobacter can be spread through contact with dog feces, but it doesn’t spread from human contact. The CDC also said "regardless of where they are from, any puppy and dog may carry Campylobacter germs."

It’s more common for the bacteria to spread from puppies, not adult dogs, because of undeveloped immune systems. The symptoms include diarrhea, fever and abdominal pain. They can last up to seven days, but won’t necessarily show until two-to-five days after infection.

The Campylobacter infection can be tricky, even for veterinarians, said Dr. Ashley Apking with Millis animal hospital

"It's not something we will routinely check for," she said.

That's because diarrhea is one of the symptoms. And that can be confused with a number of diseases and viruses.

"Sometimes if they are not responding to treatment than we look further, then you have to do a special kind of fecal testing," she added.

Apking said you can get the infection from raw and uncooked food. But, in this case, humans could be getting it by simply playing with a dog that has the bacteria.

"Puppies clean themselves, they lick themselves, you pet the puppy and go eat a snack that would be a way to get it," Apking said.

She recommends taking extra precautions to avoid contamination.

"Always wash your hands after you handle an animal just practice good hygiene," she said.

Apking said because of the outbreak, it will now be on their radar.

"We will definitely be aware and keep our eyes open," she said.

The CDC is investigating, along with state health departments, to determine the source of the bacteria.