KANSAS (KSNW) – A nationwide salmonella outbreak has been linked to small turtles that can be purchased online, according to the Centers for Disease Control and Prevention.

The CDC announced this week that salmonella cases in 11 states — Florida, Iowa, Kansas, Massachusetts, New York, Ohio, Pennsylvania, South Carolina, Tennessee, Virginia, and Washington — have been linked to the turtles.

In May, the Tennessee Department of Health collected samples from two small turtles owned by someone who had become ill. Those turtles, purchased online, were found to have salmonella.

Since then, 15 people have been infected, and five hospitalized. No deaths have been recorded.

Many of the salmonella cases in this outbreak were observed in children, the CDC added. The agency also believes the total number of illnesses is likely higher than 15, as some people may have recovered without medical care, and without reporting their illnesses.

Many of the people sickened in the outbreak reported purchasing turtles with shells less than four inches long, which the CDC warns against.

“Do not buy small turtles with shells less than four inches long,” the CDC wrote in its investigation notice. “A federal law bans the sale of these small turtles as pets because they have caused many Salmonella outbreaks, but they are sometimes available for sale online and at stores, flea markets, and roadside stands.”

The CDC added that turtles of any size can spread salmonella infections “even if they look healthy and clean.”

Symptoms of salmonella infections often begin to show between six hours and six days after swallowing the bacteria. Diarrhea, fever, vomiting and stomach cramps are common. Infected individuals are urged to contact a healthcare provider, especially if symptoms worsen to include bloody diarrhea (or diarrhea that lasts for more than three days), fever of over 102 degrees F, frequent vomiting that prevents the ingestion of liquids, or any sign of dehydration.

“But antibiotics can be used to treat people who have severe illness or who are at risk for severe illness, such as people with weakened immune systems, infants, or adults age 65 or older,” a representative for the CDC previously told Nexstar.

Anyone considering the purchase of a pet turtle can find more information about proper practices and care on the CDC’s website.