The deadly meningitis outbreak that has claimed a dozen lives is prompting calls for increased oversight of the nation's custom-made pharmaceutical industry, amid charges that the company at the center of the scare may have misled U.S. regulators.

On Wednesday, Idaho became the 11th state to report a case of the rare illness, which has been linked to tainted steroids produced by a specialty pharmacy in Massachusetts.

The U.S. Food and Drug Administration, whose role in the outbreak has come under criticism, said it was planning an afternoon media briefing on Thursday.

In all, 138 people have contracted meningitis as a result of the now-recalled drugs, according to the latest tally from the U.S. Centers of Disease Control and officials in 11 states where the outbreak has spread. The case in Idaho is the first discovered in the western United States.

Lawmakers have come under pressure to close what critics see as a loophole in oversight that left the New England Compounding Company (NECC), the Massachusetts pharmacy linked to the tainted steroids, largely exempt from federal regulation.

The FDA regulates only the ingredients and their suppliers, not the little-known corner of the drug world known as "compounding," which is subject to a patchwork of state oversight.

State and federal officials are now investigating NECC, which distributed thousands of vials of a contaminated steroid made at a shabby brick complex next to a waste and recycling operation in a western suburb of Boston.

The pharmacies are owned by Gregory Conigliaro, an engineer, and his brother-in-law, Barry Cadden, a pharmacist who was in charge of pharmacy operations at NECC. The waste and recycling facility is another of Conigliaro's business interests.

Compounding pharmacies such as NECC are permitted to make medications based on specific prescriptions for individual patients.

State and federal regulators are investigating why NECC shipped thousands of vials of preservative-free methylprednisolone acetate steroid to healthcare facilities in multiple states.

"It does seem like the agencies, both at the state and the federal level, may have been misled by some of the information we were given," Massachusetts Governor Deval Patrick told reporters on Wednesday.

The number of cases has grown rapidly as health practitioners contacted about 13,000 people who received injections from a potentially tainted supply of steroid medication shipped to 23 states.

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.

Thousands of people received the injections to relieve back pain and other complaints and are at risk of infection.

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.