The parents of a 7-year-old girl who died from an illness caused by a tick bite are speaking out in hopes that their story will educate others about the potential dangers.

Ellen Cary of Lewistown in rural northeast Missouri became ill on May 13 and died 10 days later.

Losing his daughter was "the worst thing you could ever imagine," Eric Cary said.

When Ellen had a fever on Mother's Day, her parents took her to a walk-in clinic in Quincy, Ill., where a doctor diagnosed Ellen with an upper respiratory infection and prescribed an antibiotic.

Her parents took her back two more times that week. At first, the child was given a new medicine. Then the clinic doctor said Ellen should be hospitalized because she was dehydrated. There, physicians thought she had mononucleosis, walking pneumonia and a urinary tract infection because of the dehydration.

Later that week, the child began vomiting and saying things that didn't make sense, her parents recalled. She was flown to St. Louis Children's Hospital. Three days later, the family was told Ellen had a rare disease called hemophagocytic lymphohistiocytosis, or HLH, and she was in acute liver failure.

But on May 23, doctors determined Ellen had ehrlichiosis, a tick-borne disease that had triggered the HLH. She died that afternoon.

The Carys, who have a 15-year-old son and 8-year-old daughter, said they don't blame the doctor who treated Ellen initially because ehrlichiosis mimics common illnesses. Symptoms include fever, headache, joint pain, fatigue and sometimes a rash.

"Ellen, she was one of a kind," her father said. "She loved Mommy and Daddy and everybody else. She always worried about other people before she worried about herself."

Last spring, Ellen cut her hair for Locks of Love.

"She came home and said, 'Dad, I'm going to do it for the next five years,' " Eric said. "She wasn't stingy. She wasn't selfish. She'd do anything you'd ask her to do. She never complained about anything. She was one in a million, I guess."

Eric Cary said the family often would go fishing or mushroom hunting together, and because of their time outdoors, ticks were a part of life.

The Carys want other parents to be vigilant about the possibility of illness caused by tick bites.

In addition to prevention efforts, such as examining the body for ticks after time outdoors and using repellent, Eric Cary said it's important to get immediate medical attention if a tick bite is suspected and if flu-like symptoms occur.