Updated

Public health officials said Thursday there is a "light at the end of the tunnel," referring to a new analysis from the Centers for Disease Control and Prevention suggesting the risk of death or stroke is mostly gone by 42 days after exposure to the contaminated steroids implicated in a nationwide meningitis outbreak.

Contaminated injections of methylprednisolone acetate from the New England Compounding Center in Massachusetts are blamed for 317 cases of fungal meningitis and other infections in 17 states. At least 24 patients have died.

Although the medication was recalled in late September, public health officials continue to report new cases because fungal meningitis has a relatively long incubation period.

According to Dr. John Dreyzehner, the commissioner of the Tennessee Department of Health, patients who have become ill in Tennessee show symptoms an average of 18 days after injection.

He said of the 1,009 people exposed to the potentially contaminated medication in his state, all but 250 had already moved beyond the period of highest risk, and the remainder would pass the 42 day mark by Nov. 8.

As federal investigators continue to probe the source of contamination at NECC, some lawmakers and public health advocates are calling for increased federal oversight of compounding pharmacies.

"We can't… rely on a patchwork of state regulation to assure adequate regulation of what is effectively interstate commerce," Dreyzehner said.

However, the Tennessee health commissioner added that any new oversight must balance safety concerns with the need of patients to have continued access to important medications.

"At the end of the day, we are all clinicians," Dreyzehner said. "We are all people who are providing care to people who are in need. And if we lose sight of our commitment, of our oath to do no harm, no amount of regulation can fix that."