WASHINGTON - Suspected anthrax bacteria was detected at a mail delivery facility at the Pentagon and at another satellite facility Monday, but subsequent tests have proved negative, the Defense Department said.
The department said further testing was being performed but conclusive results would not be ready for 48 to 72 hours.
The Pentagon said cultures were taken from the estimated 275 people who may have been exposed to anthrax. They were issued three day supplies of antibiotics as a precaution, it said.
"During routine mail operations the Pentagon had a positive detection for the presence of anthrax bacteria at the Remote Delivery Facility," the Pentagon said in a statement.
The facility, which processes mail and other deliveries to the Pentagon, was evacuated while further tests were conducted, it said.
"Subsequent tests have proven negative. However, the department is taking precautionary measures while further testing is conducted."
A Pentagon spokeswoman, Lieutenant Commander Jane Campbell, said another positive detection for anthrax was made at a mail facility at an unidentified Defense Department facility in suburban Virginia.
Campbell said the mail and other deliveries had already been irradiated before arriving at either facility.
In both cases, she said, the detections were made with mail screening devices that were sensitive enough to detect the presence of anthrax even if had already been killed by irradiation.
Follow-on tests for the presence of anthrax were negative in both cases, she said.
Moreover, no other sensors at the Pentagon produced positive readings for anthrax, she said.
About 175 people worked in and around the facility, and another 100 people may have come in contact with the mail during delivery, according to the Pentagon.
It was unclear how many people were at risk of exposure at the second site, which was described as a building that houses Defense Department offices.
Anthrax is a bacteria which can be deadly if inhaled. Symptoms include fever, sweat, and chills, but typically they do not manifest themselves for several days.
The US Army Research Institute for Infectious Diseases at Fort Detrick, Maryland was conducting follow-on tests.
Besides the Pentagon security, the Centers for Disease Control and Prevention, the Department of Health and Human Services, the Federal Bureau of Investigation and the US Postal Service responded to the incident, the Pentagon said.
Authorities have yet to solve a rash of anthrax attacks in 2001 that killed five people and sickened 17 others.
Letters with anthrax were mailed to the US Congress, a television news office in New York, and the headquarters of tabloid newspaper in Florida.
03/15/2005 00:43 GMT