The death toll in the United States from an unprecedented outbreak of fungal meningitis linked to a contaminated drug has climbed to 23 people, health officials said Saturday.
The number of infections tied to the tainted steroid rose to 284 in 16 states, the Centers for Disease Control and Prevention reported on its website.
Officials have said at least 14,000 people in 23 states could be at risk and that it could be weeks or even months before authorities have a final tally of the infections, due to the disease's long incubation period.
The southern state of Tennessee remains the hardest hit with 69 cases and nine deaths, followed by Michigan with 53 cases and five fatalities.
Other badly hit states include Florida, Indiana, Maryland, New Jersey and Virginia.
The tainted steroid—typically injected into the spine to treat back pain—was produced by the New England Compounding Center in Massachusetts, which has since shut down its operations and recalled all of its products.
Early tests had shown fungus in unopened vials of the medication, but it took until Thursday to confirm it was the type which causes the rare form of meningitis: Exserohilum rostratum.
Health officials have widened their outreach efforts to include people exposed to other injectable and high-risk NECC products after three patients who had used different drugs produced by the firm also developed meningitis.
The outbreak has led to calls for tighter regulation of the loosely controlled pharmaceutical compounding industry.
Critics say drug manufacturers have found a way to sidestep costly and strict oversight by classifying themselves as pharmacies, which are given freer rein to mix drug compounds for patients.
The rare strain of meningitis, which inflames the protective membranes covering the brain and spinal cord, requires a lengthy hospital stay and intravenous medications. However, it is not contagious in this form.
Three of the 284 cases are for peripheral joint infections, the CDC said.
Explore further: Tainted drug death toll rises to 14 in US