Ameridose, a drug manufacturer owned by the same people who own New England Compounding Center, or NECC, has been closed since October 10. It will remain shuttered until November 5 while authorities inspect the plant, at least temporarily cutting off supplies to its customers.

NECC shipped thousands of potentially contaminated vials of a steroid used for injections to treat severe back pain. Some 14,000 patients may have been exposed to the medicine that has so far led to 23 deaths.

Twelve additional fungal meningitis cases were reported on Monday, bringing the total to 294 in 16 states, plus three cases of peripheral joint infection likely linked to the tainted steroid, according to the U.S. Centers for Disease Control and Prevention. No additional deaths were reported.

Nine of the new cases were reported in Michigan, which has reported 63 infections and five deaths. Tennessee has been hardest hit, with 69 reported cases and nine deaths.

Two more have been reported in Indiana, and one in Maryland, the CDC said.

Congressional investigators said on Monday that federal and state health regulators knew of potential problems with NECC steroid treatments as early as 2002, when officials began inspecting NECC's facility after the report of an adverse health event linked to the drug.

All NECC products have been recalled, but no Ameridose products have been linked to meningitis or faced recall. NECC and Ameridose are based in the suburbs of Boston.

On Monday, the U.S. Food and Drug Administration provided on its website a list of all customers who received NECC products on or after May 21. here

REMAINING VIGILANT

Although only the steroid methylprednisolone has been confirmed as contaminated thus far, the FDA has recommended that healthcare professionals follow up with any patients who were administered any injectable product shipped by NECC on or after May 21, including drugs for eyes or cardioplegic solution used in open heart surgery. It said patients should remain vigilant for any signs of infection and contact physicians if they are concerned.

Symptoms of fungal meningitis include fever, headache, stiff neck, nausea, sensitivity to light, slurred speech and changes in mental function.

The FDA posted a statement on its website on Saturday saying the production shutdown of Ameridose might affect supplies of "certain drugs for some health care systems." It said it was working with Ameridose to ensure that its drugs are safe.

The agency directed hospitals and clinics to its drug shortage website for information on the availability of drugs that are in short supply. It did not, however, identify which drugs or healthcare systems were being affected by the lack of Ameridose products.

NECC is being investigated by federal and state authorities to determine if it violated compounding pharmacy regulations by supplying large orders of medicines without matching its drugs to specific prescriptions for patients or treatment regimens. It is also facing a raft of lawsuits connected to the meningitis outbreak.

Although the typical incubation period for contracting fungal meningitis from the tainted steroid is one to four weeks after injection, it can be far longer. Doctors have been cautioned to monitor patients for signs of meningitis for several months after they received injections.

Rapid treatment with a powerful antifungal drug is considered crucial to prevent the infection from spreading to the brain, where it has caused strokes and other damage.

Patients who received injections of NECC drugs before May 21 and who have not had infection symptoms are considered to be at less risk because of the time that has elapsed, the FDA said. Patient follow-up was not recommended for those who received non-injected NECC products such as lotions and eye drops, which are considered to be low risk.

(Reporting by Bill Berkrot; Editing by Maureen Bavdek, Richard Chang and Peter Cooney)

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