Conn. (WTNH) — The Centers for Disease Control and Prevention is investigating a multistate outbreak of Salmonella infections linked to small turtles purchased online.

According to the CDC, 15 people have been infected with the outbreak strain of Salmonella from 11 states, including five that were hospitalized. Most of these outbreaks have occurred within children. The CDC noted that the true number of sick people is likely higher than the number reported, as some people recover without receiving medical care or being tested for Salmonella.

According to interviews and laboratory data, small turtles with shells less than 4 in. are making people sick. Most people reported buying the turtles online from the site myturtlestore.com, even though federal law bans the sale of small turtles as pets.

The CDC warned potential pet owners to only buy turtles with shells longer than 4 in. from reputable pet stores. Additionally, it’s important to always stay healthy around a turtle by washing your hands after interacting with the pet.

Anyone with Salmonella symptoms, including diarrhea, fever, and stomach cramps for six hours to six days after being exposed to the bacteria should reach out to a doctor. The illness usually lasts between four and seven days, and most people recover without treatment. However, the illness may be severe for children under the age of five or adults 65 and older, which could lead to hospitalization.

For more information regarding cases in the state, visit cdc.gov.