Washington Another deadly anthrax-laced letter could still be undiscovered and health officials are urging thousands of people who work in mailrooms across Washington to begin taking antibiotics.
White House Chief of Staff Andrew Card said Sunday that "there may be other letters that are stuck in the system."
"Our postal service, the FBI, are working very hard to understand all they can. And we're asking people to be very careful," he said on "Fox News Sunday."
Deputy Postmaster General John M. Nolan said Sunday that there are a lot of suppositions among investigators about more letters, "but I don't have any way of knowing."
However, he added on CBS' "Face the Nation:" "There is no evidence of new anthrax in the system anywhere."
Postal officials signed a $40 million contract to buy eight electron-beam devices to sanitize letters and packages. The equipment will be used first in the nation's capital, where the anthrax scare has spread from mail centers for Congress and the White House to the Supreme Court and the CIA.
"The Postal Service will do whatever it takes to continue to serve the American people," Deborah Willhite, a senior vice president of the post office, said Sunday. "The Postal Service is not optional."
"We understand that the threat can go beyond anthrax and we are looking for a multiple defense," she added in an appearance on C-SPAN'S "Washington Journal."
Dr. Anthony Fauci of the National Institutes of Health noted Sunday that the antibiotic doxycycline is now being recommended for people exposed to anthrax, rather than Cipro which can have more side effects.
Another suspicious item surfaced Saturday in Florida when a letter on its way to U.S. Rep. Mark Foley's office in Palm Beach Gardens, Fla., started seeping white powder in the local post office. The letter, which was handwritten and had no return address, was sent to an FBI lab in Miami for testing.
In New Jersey, where five postal workers have contracted anthrax, state health officials are advising about 600 people who visited nonpublic areas of a Hamilton Township mail processing facility where anthrax was found to take antibiotics.
While no new cases of contamination had been reported in Washington over the weekend the Postal Service buried a second mail handler who died from anthrax poisoning
Senate Majority Leader Thomas Daschle of South Dakota said Americans must move forward.
"We cannot be paralyzed by our anger or slowed by our sadness. We need to identify the weaknesses in our system of confronting bioterrorism so that we can protect our people," Daschle said Saturday in the Democratic response to the president's weekly radio address.
A letter containing anthrax was found earlier in his Capitol Hill office.
Police and health experts continued testing for anthrax contamination in congressional offices and postal facilities. The Ford and Longworth buildings at the House of Representatives and the Senate's Hart office building remained closed, as well as the mailroom in the Dirksen building.
Some 68 tons of mail were being trucked from the capital to a plant in Lima, Ohio, to be decontaminated with electron beams normally used to sterilize hospital equipment.
About 10,000 postal workers have been placed on antibiotics as a precaution and Washington's public health director, Dr. Ivan Walks, urged the same for workers in private mailrooms that receive material from the Brentwood mail distribution center. That, he said, could cover 2,000 to 4,000 mailrooms.
The two mail handlers killed by anthrax worked at the now closed Brentwood facility, which processes mail for federal agencies and the rest of the city.
"We don't know if we have cross-contamination from the original Senator Daschle letter or if there is another letter out there that we need to be concerned about," Lt. Dan Nichols of the U.S. Capitol Police said Saturday.