Anthrax probe looks at how spores got into publisher's mailroom

Investigators want to know how anthrax spores were introduced into a Florida publishing house.

BOCA RATON, Florida (CNN) -- Federal investigators on scene at a Florida tabloid office are seeking clues that would help explain how anthrax spores got into the newspaper mailroom and onto three employees, including one who died from the disease.

The American Media Inc. offices of the supermarket tabloid The Sun remained closed on Friday and employees worked from satellite offices while investigators scoured their building.

Robert Stevens, a 63-year-old Sun photo editor, died a week ago from inhalation anthrax, contracted from breathing the deadly bacteria. Two other employees -- mailroom worker Ernesto Blanco, 63, and Stephanie Dailey, 36, have tested positive for exposure to anthrax, but are exhibiting no symptoms.

RESOURCES Florida Department of Health  anthrax hotline: 1-800-342-3557

FBI Deputy Director for Terrorism Tim Caruso told the House Select Intelligence Committee on Thursday that additional spores had been found on Stevens' computer keyboard and in the mailroom.

"At this time, the presence of anthrax has been confirmed in a number of locations and testing continues," Caruso said.

Caruso also told the committee that investigators have found "no connection between the anthrax and the terror attacks of September 11.

"The anthrax appears to be an isolated incident," he said.

Dailey says she feels "fine" despite her exposure to anthrax.

On Thursday, Dailey -- the latest Sun employee to test positive for anthrax -- told reporters that she felt "fine" and "went to work today."

"When I first found out, it was like the wind knocked out of you because you don't know what it means until it's explained to you," Dailey told reporters outside her Boynton Beach, Florida home.

She said she is taking antibiotics to fight off any effects from the disease and has not been hospitalized.

Blanco, however, remained hospitalized, where he was undergoing treatment.

Dailey, an office services assistant at AMI, said part of her job includes working in the mailroom.

Authorities said it appeared that the same strain of anthrax -- found naturally in the tissues of dead animals --is responsible for all three human exposures to the bacteria as well as the spore discovery in the mailroom and on Stevens' computer keyboard.

They could not, however, say with certainty if the strain was man-made. Sources have told CNN that investigators are leaning toward the possibility that the strain originated at a laboratory in Iowa and had been widely distributed to researchers of the past 50 years.

Concern over the possibility of bioterrorist attacks have risen dramatically in the wake of the September 11 terrorist attacks in New York, Washington and Pennsylvania -- and as the United States and its allies launched retaliatory strikes against those believed responsible for the attacks.

Several false alarms have been reported, but the Florida cases are the only confirmed cases of anthrax contamination.