FREDERICK, Md. — Actor Kevin Spacey's character dies of a deadly virus in the movie "Outbreak" after he stretches his air hose too far and it rips a hole in his protective biohazard suit.

That's just Hollywood.

"It's not at all like that," said Dr. Lisa Hensley, a civilian microbiologist for the Army who wears the identical full-body suit while handling Ebola strains so deadly they kill 90 percent of infected victims. Safety features of the suit and her top-security laboratory, called a "hot zone," make the movie scenario unlikely, she said.

Hensley, 35, is on the front line of President Bush's expanding program to defend the country against biological attacks.

One of the Army's top dangerous disease scientists, she's in charge of a team at Fort Detrick, Md., working on vaccines and treatments to counter a germ attack or natural outbreak.

She works with deadly viruses including Ebola, Marburg, Lassa, Machupo and Junin. She has researched severe acute respiratory syndrome and smallpox, and helped develop possible treatments for SARS and Ebola.

The U.S. Army Medical Research Institute of Infectious Diseases, Hensley's employer, is responsible for protecting soldiers but works closely with civilian agencies that guard against epidemics.

The number of top-security labs is increasing. The Government Accountability Office reported last fall that there were five such labs — designated Bio-Security Level 4 — registered before the Sept. 11, 2001, attacks. With expansion of the bio-defense program, the number will expand to 15, the GAO said. USAMRIID, as it is known, is not new: it was created in 1969.

Sharp objects main hazard

Hensley has one of the world's most dangerous jobs, but she is more concerned about a needle, a scalpel or other sharp instrument penetrating her layers of gloves than a rip in her suit.

Not long after starting her Army work in 1998, she cut through her gloves with a blunt scissors while working with Ebola. Her finger was bleeding. She left the lab and quickly washed her hands.

"I was fine until everyone else started freaking out," she said. In fact, there was only one thing she was allowed to do: go quickly to her facility's isolation ward, called "The Slammer."

There, doctors decide whether a worker lives in isolation for up to a month, depending on a particular virus' incubation period.

"If I hadn't washed my hands, I would have been in The Slammer 28 days," she said. Instead, she was allowed to leave but was monitored for the next three weeks.

Despite the danger, only 20 people have been kept isolated in The Slammer in the past 35 years, and none became ill, Hensley said.

It's not like in the movies

Life in these labs doesn't imitate Hollywood. Hensley said the part of the biohazard suit where the air hose attaches is reinforced and has never ripped in her work experience.

Even with such a tear, as imagined in "Outbreak," the worker would be safe. Fresh air would still be pumped in, and air would continue to exit the suit through a series of one-way valves called baffles, and go out through the rip.

The system creates a shield for the lab worker. Fresh air also is coming into the room, making the risk of exposure from a tear almost negligible, Hensley said. There is enough air in the suit to last five minutes after disconnecting the air hose, normally adequate for getting out of the containment area.