The U.S. Centers for Disease Control and Prevention says dozens nationwide have contracted a salmonella infection linked to turtles.

CDC officials said Tuesday that 37 people across 13 states became sick with infections stemming from contact with pet turtles. No deaths have been reported, but 16 people have been hospitalized.

The CDC says the illnesses began to appear March 1 and diagnoses continued until Aug. 3. Almost half of the 33 people interviewed by the CDC said they had come in contact with a turtle or its environment.

The CDC says the outbreak could continue.

CDC officials warn not to buy small turtles as pets or give them as gifts. They say all turtles can carry salmonella bacteria even if they look healthy and clean.