Washington anthrax alarms appear false

Mar 16, 2005 (CIDRAP News) The anthrax alert that shut down several government buildings in the Washington, DC, area this week and put hundreds of workers on preventive antibiotic treatment apparently was a false alarm.

Testing of more than 70 samples from a mail facility near the Pentagon in Arlington, Va., and a mailroom at an office complex in nearby Falls Church, Va., showed no trace of anthrax, the Washington Post reported today.

An unnamed military official told the Post and the New York Times that contamination in a military contractor's laboratory in Richmond, Va., might have triggered the initial finding of anthrax on a filter from the Pentagon mail facility on Mar 14.

There was no indication in today's reports what might have caused the anthrax alert later the same day in a Department of Defense (DoD) mailroom at the Falls Church complex, called Baileys Crossroads Skyline. Fairfax County officials announced this afternoon that the complex would reopen tomorrow, but that one suite would remain closed pending further test results.

Officials have said there was little chance of live anthrax spores contaminating either building via mail deliveries, because all mail to both facilities is irradiated before it arrives. Routine irradiation to kill pathogens was begun as a result of the mail-borne anthrax releases of October 2001, which killed five people and sickened 17 others.

This week's alert had prompted the government to close a Washington post office that processes mail for the DoD and other government agencies and to recommend antibiotic treatment for about 200 workers there. Mail delivered to that facility is also irradiated before it gets there.

The post office, on V Street Northeast, was to reopen at noon today, the Post reported. Postal Service spokesman Gerry McKiernan said workers at the site who had started taking antibiotics were being told they could discontinue them.

The Post report said DoD officials had recommended that nearly 700 DoD workers take preventive antibiotics. Federal and local health officials recommended that they continue taking them until final test results are in, the story said.

The episode began the morning of Mar 14, when a military contractor that handles biohazard monitoring at the Pentagon mail facility reported evidence of anthrax on a filter that had been sampled Mar 10. The mail facility was closed, and 263 workers there provided nasal swab samples for testing.

A sensor in a mailroom at the Skyline Five Place sounded an alarm at 2:30 p.m. the same day. Emergency crews were called, and about 800 workers in three connected buildings were confined there for 6 hours.

The Pentagon sample that tested positive in the contractor's lab was subsequently retested by the US Army Research Institute of Infectious Diseases (USAMRIID) in Maryland. There, a polymerase chain reaction test confirmed the positive finding early yesterday morning. But subsequent culturing of samples to detect live bacteria yielded only negative findings, the Post reported today.

The military official quoted anonymously by the Times said the original anthrax finding in the contractor's lab appeared to be related to quality control problems. He said labs that test for anthrax normally keep a sample of anthrax on hand to calibrate equipment. Evidence suggested, he said, that this sample had somehow contaminated the sample from the filter at the Pentagon mail facility. The same contaminated sample then was tested by USAMRIID, he said.

DoD's top health officer, Dr. William J. Winkenwerder, said authorities didn't find any mail that could have triggered detection equipment, according to a report by DoD's American Forces Press Service (AFPS). Nor did the government receive any threats, the Post said.

DoD officials said they had found no link between the alerts at the Pentagon facility and the Skyline Five complex, according to the Post.

Winkenwerder said the negative follow-up test results in the current episode contrasted sharply with what happened in 2001, according to the AFPS report. At that time, "There were multiple positive tests from the environment, sort of all over the place," he said. "We don't have any of that at this time, despite a lot of testing."

This week's episode sparked some complaints of lack of communication and coordination between government agencies. Virginia and Fairfax County officials were angry that DoD didn't alert them immediately about the anthrax alert at the Pentagon facility, according to the Post. Also, the story said, a Bush administration official voiced concern that the Department of Homeland Security had not been alerted.