As the much-anticipated, new "Teenage Mutant Ninja Turtles" movie rolled into theaters last week, young fans are clamoring for plastic swords, blue bandannas and (foam) throwing stars.

Some, perhaps many, also will want a turtle as a pet.

While these glassy-eyed creatures may look cute, harmless, and like a fun and easy family pet, experts warn that turtles require a surprising amount of care and they carry harmful germs that can make people very sick. The American Tortoise Rescue is pleading with parents, asking them to fight the temptation to get their children real turtles after watching the new "TMNT" movie.

An open letter from the California-based nonprofit says after the first movie was released in 1990, hundreds of thousands of live turtles became pets. Most of them were water turtles called red-eared sliders. Children quickly realized these were not ninja turtles. They don’t soar, jump or even like pizza.

They lost interest. The organization believes as many as 90 percent of these turtles were dumped into rivers, lakes or trash bins, flushed down toilets or sent to turtle rescue organizations.

The bigger problem, the organization reminds parents, is turtles carry salmonella. People can get salmonella from contact with a pet turtle or its environment, including the water from containers or aquariums where they live. Salmonella can cause serious, even life-threatening infection in people even though the bacteria don’t make the turtles sick.

Hundreds of people have become ill in several ongoing, nationwide salmonella outbreaks linked to small turtles, according to the Centers for Disease Control and Prevention. Most victims are children under 5 years old. From May 23, 2011, to May 6, 2013, the CDC received reports of 391 salmonella-related illnesses in 40 states and the District of Columbia; most of those ill were children. There were no deaths, but 63 people needed to be hospitalized.

The investigation showed that shortly before most of the people became ill, they were exposed to a turtle by touching, feeding, cleaning the habitat, or changing the water in the tank.

The CDC urges families with children under 5 to avoid keeping reptiles or amphibians as pets, noting kids’ immune systems are still developing and they are more likely to put their fingers in their mouths after touching the pet. The American Tortoise Rescue does not recommend live turtles or tortoises for children under 13, in part because the organization says kids lose interest almost immediately.

Grover Brown, a turtle enthusiast, keeps a trio of common musk turtles as pets. They are tiny, but he keeps them in large tanks to provide a higher qualify of life.

About a year ago, David Bakke and his son Nicholas, 7, found a box turtle in the backyard of their Norcross, Ga., home.

Bakke agreed to let his son keep the turtle as a pet.

They made an outdoor cage with a flower bed and nylon cover for "Robby the Turtle."

But it was a challenge to get the turtle to eat anything. He never seemed happy, Bakke recalls, and there were days when the turtle didn’t seem to budge.

"All he ever did was try to escape and run away, which he eventually did," Bakke said. By then, his son had lost interest. Meanwhile, Bakke discovered reports linking the cute creature to serious illnesses.

"Your overall chances of getting sick may not be significant, but my personal belief is that if you end up being one of those getting sick, it doesn’t matter what those chances are. … I would never consider getting a pet turtle again."