ATLANTA (October 14, 2012)--At the main campus of the U.S. Centers for Disease Control and Prevention in Atlanta, dozens of people are working day and night to bring a meningitis outbreak under control.

Dr. John Jernigan, a medical epidemiologist at the CDC leading the clinical investigation team for the outbreak response, said the infection, which is caused by a fungus, is very unusual.

Meningitis is typically caused by a virus or bacteria.

The fungus linked to this outbreak is common in dirt and grasses, but it is making people sick because it found its way into a steroid injected into people with back pain.

That steroid was distributed by a Massachusetts pharmacy that is currently under investigation.

Nearly 200 people in more than a dozen states have been sickened, including 15 who have died.

One case has been confirmed in Texas.