(TODAY HEALTH) — After a week of speculation and months of worry for the families of 12 girls affected by a mystery illness that causes severe Tourette’s-like tics and verbal outbursts, the doctor who has treated 10 of the girls from upstate New York offered new details on their condition.

Since TODAY first reported the baffling cases Monday, the show has received overwhelming response from parents and viewers worried about the cause of the sudden illness and wondering why doctors have been unable to treat the girls.

Dr. Laszlo Mechtler says there is nothing for the community or other parents to fear.

“I’d like to reassure the community that this is not an infectious disease,” Mechtler, vice president of the Dent Neurological Institute, told TODAY’s Matt Lauer Friday. “It’s not contagious. These are real symptoms. But these girls will get better. We have to give them time and space.”

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