So far two people have died and 18 others have been sickened in Tennessee from meningitis linked to the outbreak. Four other states have reported cases, with a total of 26 illnesses and four deaths, said Centers for Disease Control and Prevention spokesman Curtis Allen.

In addition to the 18 who are sick in Tennessee, one case has been reported in North Carolina, two in Florida, three in Virginia and two in Maryland. The other deaths include one each in Virginia and in Maryland, Allen said.

"Some are improving and some are in critical condition," Dr. David Reagan, chief medical officer for the Tennessee Health Department, said of the sickened patients during a press conference.

The Tennessee Department of Health, the CDC and the Food and Drug Administration are teaming up in the investigation of the spread of the non-infectious form of meningitis that is tied to the lumbar epidural injections, according to state health officials.

The Saint Thomas Outpatient Neurosurgery Center in Nashville has already contacted all patients who received the injections between July 30 and September 20, when it voluntarily closed down.

State officials said that now the center will begin reaching back to the beginning of July to check on the patients and any possible symptoms of the disease.

The state health department said the "prime suspect" in the illnesses is methylprednisolone acetate -- a steroid that has been removed from shelves in the Tennessee facilities.

"We are extremely saddened by the impact this tragic situation has had on our patients and their loved ones and we are working quickly to get answers," state Health Commissioner Dr. John Dreyzehner said.

A facility in Crossville, Tennessee, about 100 miles east of Nashville, has ceased giving the steroid injections, officials said. One of the cases reported in the last 24 hours includes a person who received an epidural injection at that facility.

Health officials said the fungal meningitis responsible for the outbreak was not connected to the more common forms of bacterial and viral meningitis and it is not contagious.

"None of us have had anything like this ever," said Dr. Robert Latham of Saint Thomas Hospital.

And it's not over, according to the CDC's Allen.

"We're investigating a number of medications and products that may have been associated with the disease," he said Wednesday night, adding that they have not "with absolute certainty" been able to pinpoint the source or cause.

"We are coordinating with multiple state health departments, trying to uncover any additional cases that may be out there," Allen said. "We expect additional cases."

(Editing by Lisa Shumaker)

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