UPDATE 1-More U.S. cases of meningitis confirmed in deadly outbreak

(Adds details of investigation, background)

By Tim Ghianni

NASHVILLE, Tenn., Oct 5 (Reuters) - Tennessee confirmed on Friday four more cases of rare fungal meningitis, as health officials in 23 states scrambled to notify thousands of patients who received steroid injections linked to an outbreak that has killed five people.

Three of the dead were in Tennessee, where the outbreak began, and one each in Virginia and Maryland. The four new illnesses in Tennessee brought to 29 confirmed cases in that state and a total of 39 in six states.

"It is imperative that we continue our efforts to protect Tennesseans," Dr. John Dreyzehner, the state's health commissioner, told a news conference.

The steroid medication may have been administered to patients in 23 states, according to the U.S. Centers for Disease Control, raising concerns the number of cases will increase.

The steroid is usually injected to control back pain. While fungal meningitis is rare and life-threatening, it is not spread by person-to-person contact.

The infected patients have shown a variety of symptoms from one to four weeks after their injection including fever, a new or worsening headache, nausea and new neurological deficits that would be consistent with deep brain stroke, the CDC said.

All the cases have so far been traced to three lots of the steroid prepared at New England Compounding Center Inc in Framingham, Massachusetts. The company said it has suspended its operations while the investigation is ongoing.

The Massachusetts Health Department said there were 17,676 vials of medication in each of the three lots of methylprednisolone acetate sent out July through September and have a shelf life of 180 days.

The CDC said it had not yet determined the rate of infection among patients who received the potentially tainted steroid. The rate of infection is important because it would help pinpoint the scope of the potential outbreak.

In addition to Tennessee, four cases have been reported in Virginia, two in Florida, two in Maryland, one in North Carolina and one in Indiana, the CDC said.

The steroid was sent to California, Connecticut, Florida, Georgia, Idaho, Illinois, Indiana, Maryland, Michigan, Minnesota, North Carolina, New Hampshire, New Jersey, Nevada, New York, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, Virginia, Texas and West Virginia, the CDC said.

Each state could have hundreds of patients or more who were exposed through injections.

In Indiana, which had one case, St. Mary's Health said on Thursday that 560 patients had received the medication at the Surgicare Cross Pointe clinic in Evansville.

Minnesota had no reported confirmed cases on Friday, but up to 600 patients may have been exposed to the tainted medication, state health department spokesman Buddy Ferguson said.

(Reporting by Tim Ghianni; Writing by David Bailey; Editing by Greg McCune and Philip Barbara)

((david.bailey@thomsonreuters.com)(312 371 4002))