The toll from the outbreak of fungal meningitis tied to contaminated steroid shots that has killed 12 people in the United States was expected to grow on Wednesday, raising pressure for stricter oversight of a largely unregulated corner of the pharmaceutical world.
On Tuesday, the outbreak claimed four more lives and Florida became the latest state to report at least one death linked to the illness in a widening health scare.
Since the September 25 recall of three lots of a steroid produced by a Massachusetts company, the outbreak has spread to 10 states and infected 121 people, according to state health departments and the Centers for Disease Control and Prevention.
In five states -- Tennessee, Michigan, Maryland, Virginia, and Florida -- the outbreak has claimed lives, with the latest victim a 70-year-old man in Florida.
As many as 13,000 people received the injections to relieve back pain and other complaints and are at risk of infection, the CDC said, although the number ultimately stricken is likely to be far fewer.
For the first time on Tuesday, Tennessee state health officials gave an estimate of the rate of infection among those patients who received injections from the recalled steroid supplies.
Approximately 5 percent of patients treated with the suspect medication have contracted meningitis, said Dr. David Reagan, chief medical officer for the Tennessee Department of Health. Based on that rate of infection and the 13,000 shots given, the number of confirmed cases could grow to about 650 from the current 121.
"We expect that most people who were exposed to this will not develop a fungal infection," Reagan said.
Meningitis is an infection of the membranes covering the brain and spinal cord. Symptoms include headache, fever and nausea. Fungal meningitis, unlike viral and bacterial meningitis, is not contagious.
The outbreak has alarmed health officials and highlighted a gap in regulation of so-called pharmacy compounders, which are facilities that take drug ingredients and package them into medications and dosages for specific clients.
The federal Food and Drug Administration regulates only the ingredients and not the compounders, which are subject to a patchwork of state oversight.
Some of the thousands of people exposed may have to wait anxiously for weeks because the incubation period of the disease is up to a month, health experts said.
The potentially tainted steroid vials, which have been recalled, were shipped to 76 facilities in 23 states, the CDC has said.
Tennessee has been the hardest hit state, with six reported deaths and 39 cases of meningitis, followed by Michigan with three deaths and 25 cases, Virginia with one death and 24 cases and Maryland with one death and eight cases.
The other states with cases are Indiana (12), Florida (6), Minnesota (3), North Carolina (2), Ohio (1) and New Jersey (1).