UPDATE 2-Calls for oversight grow as U.S. meningitis scare widens

* Lawmakers seek tighter regulation of compounding companies

* Outbreak has sickened 138 people in 11 states, killed 12

* May take to early Nov. to identify all stricken in Tennessee

(Updates with latest number of cases, new case in Idaho, HHS official)

By Tim Ghianni

NASHVILLE, Tenn., Oct 10 (Reuters) - Pressure mounted for greater regulation of a little known corner of the pharmaceuticals industry in response to a meningitis scare that widened to 11 states on Wednesday with the first case confirmed in Idaho.

Since the Sept. 25 recall of three lots of a steroid produced by a Massachusetts company, 138 people have contracted meningitis and 12 have died, according to the latest tally from the Centers of Disease Control and Idaho on Wednesday.

The Idaho case was the first discovered in the western United States. The hardest hit state is Tennessee with 44 people sickened with the rare disease.

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

Congress came under pressure to close what critics see as a loophole in regulation that left the company linked to the tainted product largely exempt from federal regulation.

"We urge Congress to give FDA (the Food and Drug Administration) the authority it needs to assure these kinds of outbreaks do not happen again," said an official of the U.S. Department of Health and Human Services, who declined to be identified because of ongoing investigations.

This followed leading U.S. House and Senate lawmakers from both parties asking federal health officials on Tuesday for briefings on the outbreak as a first step toward possible legislative action to strengthen federal drug safety regulations.

Some patients expressed anger that such a sensitive area as steroid medication was so lightly regulated.

George Cary, whose wife Lilian Cary is one of three people to die in Michigan, said on Tuesday that Americans have a strong belief in their medical and political system and the outbreak should be a wake-up call to the nation.

"We don't have expectations of a faulty regulatory medical system that allows these types of mistakes to be made," Cary told reporters on his front lawn after a memorial for his wife. "So perhaps the message is, wake up America."

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 in Tennessee have contracted meningitis, said Dr. David Reagan, chief medical officer for the Tennessee Department of Health.

"We expect that most people who were exposed to this will not develop a fungal infection," Reagan said.

The rate of infection overall is not known.

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 highlighted a gap in regulation of so-called compounding pharmacies, 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 their suppliers, 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.

In Tennessee cases, officials said they had found the average incubation period to be 16 days, but they caution that it could range from six to 42 days for their patients.

Tennessee authorities believe they could still see new cases into the early part of November, though that could change as more information is collected, officials 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 44 cases of meningitis, followed by Michigan with three deaths and 28 cases, Virginia with one death and 27 cases and Maryland with one death and nine cases.

The other states with cases are Indiana (15), Florida (6), Minnesota (3), North Carolina (2), Ohio (1), New Jersey (2) and Idaho (1).

(Additional reporting by David Morgan, Susan Guyett and Meghana Keshavan; Editing by Lisa Shumaker and Claudia Parsons)