The tally from the outbreak rose to nearly 50 cases, and spread to a seventh state, the Centers for Disease Control and Prevention said Friday. The number of deaths from the rare fungal meningitis remained at five.
A seventh state, Michigan, was added to the list with four cases. Tennessee's cases now total 29; Virginia, six; Indiana, 3; two each in Maryland and Florida and one in North Carolina.
Looking for a source of the outbreak, investigators have focused on a steroid made by a specialty pharmacy, New England Compounding Center in Framingham, Mass. The steroid shots were used for back pain, a highly common treatment.
Health inspectors found fungus in at least one sealed vial of the steroid at the company's facility this week and were doing tests to identify the fungus. On Friday, officials said they have found two types of fungus in nine sick patients -- Aspergillus and Exserohilum.
The pharmacy recalled 17,676 single-dose vials of the steroid, methylprednisolone acetate, last week. Shipments went to clinics in 23 states, and on Friday, the government released a list of the 75 facilities that got doses from the recalled lots.
"All patients who may have received these medications need to be tracked down immediately," said the CDC's Dr. Benjamin Park in a statement. "It is possible that if patients with infection are identified soon and put on appropriate antifungal therapy, lives may be saved."
At the prompting of government officials, clinics are notifying patients who got shots from the recalled lots.
"There's a massive effort to contact all the patients," said Marsha Thiel, the chief executive officer of MAPS, a company that owns surgery center clinics in Minnesota.
She added, "If there's any question at all, they're being directed to go to their physician."
As a precaution, the Food and Drug Administration urged physicians not to use any of the company's products, and on Friday released a list of them that included other steroids, anesthetics and a blood pressure medicine. The company, which is now closed, said in a statement Thursday that despite the FDA warning, "there is no indication of any potential issues with other products."
There are FDA-approved versions of the steroid, sold by the brand name Depo-Medrol, in good supply. So patients who need the medicine should not encounter a shortage, the FDA said Friday.
Most of the anxiety right now, however, involves patients who got steroid shots for back pain and are worried about becoming seriously ill.
"Our phone is ringing off the hook this morning. Patients are calling. Of course, they're concerned," said Paulette Fry, practice manager at Wellspring Pain Solutions in Columbus, Ind., about 40 miles south of Indianapolis. She said the clinic was sending out lettera to about 300 patients who received spinal injections with the drug.
The first known case in the meningitis outbreak was diagnosed about two weeks ago in Tennessee. Three of the five deaths are in Tennessee; the others in Virginia and Maryland.
Meningitis is an inflammation of the lining of the brain and spinal cord. Symptoms include severe headache, nausea, dizziness and fever.
Fungal meningitis is not contagious like the more common forms. The types of fungus linked to the outbreak are all around, but very rarely causes illness. Fungal meningitis is treated with high-dose antifungal medications, usually given intravenously in a hospital.