Lyme disease is a well-known, tick-borne illness normally treated with a short course of antibiotics. But can it be chronic even after it is treated?Some doctors say it can be chronic and that some patients need a long course of antibiotics to kill the bug. But most experts say there's no proof of that, and overtreating with antibiotics is dangerous.Laura Decoste takes 26 pills every day to treat her Lyme disease. For six months, DeCoste went undiagnosed as she grew sicker."I came down with fever, a sinus infection and flu-like symptoms," said DeCoste.Lyme disease tests came back negative. But Decoste was put on a short course of antibiotics. She felt better but not for long."I had blurry vision, light sensitivity, ear pounding, slurred speech and pains all over my body," said DeCoste.Finally, a doctor in New York diagnosed her with chronic Lyme disease. A test came back positive, and she was put on a long-term course of antibiotics. Nine months in, she said, she's almost back to normal. "I'm still being treated aggressively, and I'm 90 percent better," she said.But DeCoste's doctor is one of a minority who believe chronic Lyme disease even exists. Sam Donta is one of them."There has been such a denial or dismissal of the entity of persistent infection," said Donta, an infectious disease specialist with a practice in Falmouth. "The idea that you no longer have Lyme disease because you've got some antibiotic treatment is flawed." Guidelines from the Infectious Diseases Society of America call for a short course of antibiotics --three to four weeks. Residual illness, they say, will go away."If I am going to say there's a chronic infection, it's really incumbent upon me to show that such an active infection exists," said Dr. Mark Drapkin, an infectious disease physician at Newton-Wellesley Hospital.Currently, there are no tests to indicate whether Borrelia Burgdoferi, the bug that causes Lyme, stays active in the body after treatment."To think that this wimpy bug is going to take that long to die when treated with an appropriate antibiotic is giving it a lot more credit than it's due," said Drapkin.But Donta says not nearly enough studies have been done, and the proof is in the cure."If we see patients who have had the illness for less than two years the cure rate is 100 percent," said Donta. "It may take 12 months or a year or two to get a good response." Chronic Lyme is so controversial, many insurance companies won't even cover long-term antibiotics because of the potential of serious side effects. Decoste pays out-of-pocket for doctors visits and IV antibiotics."Why do we need to prove that they are infected when you can't prove it? Isn't it more likely than not that they still have Lyme disease?" said Donta.DeCoste believes she'd never have recovered without her doctor's aggressive treatment."I think if I would have went a few months longer, I would have been debilitated maybe for the rest of my life," said Decoste.Some doctors have been reprimanded for prescribing long-term antibiotics.