WASHINGTON - Investigators said that they have "substantive leads" about the origins of the anthrax that was mailed to Senate Majority Leader Tom Daschle and triggered a partial shutdown yesterday on Capitol Hill.
Congressional leaders closed the House of Representatives a day before the scheduled weekend break after medical tests showed 31 people were exposed to anthrax from a contaminated letter mailed to Daschle.
All House and Senate office buildings also were ordered closed until at least Monday so investigators could comb the area for any additional evidence of anthrax. Senators, however, vowed that bioterrorism scares would not close their chamber.
"We will not let this stop the work of the Senate," Daschle said at an afternoon news conference. Senate Minority Leader Trent Lott added: "There is no risk there in the Capitol, and we feel confident we can continue to get our work done while taking necessary precautions to affect the people that work with us."
News of the exposure cases in Washington came as federal scientists said strains of the anthrax contained in a threatening letter to NBC news anchor Tom Brokaw were genetically identical to anthrax spores that killed a photo editor at a Florida-based tabloid newspaper and as the anthrax scare continued to spread across the country.
In Baltimore, police went on high alert after the FBI forwarded a vague threat it had received warning that anthrax would be released somewhere in the city after 1 p.m. The hour passed and no release was detected.
And in New York, Gov. George E. Pataki announced that early tests had revealed anthrax spores in one room of his Manhattan offices.
Pataki said the bacteria, identified yesterday as anthrax, were found in a room used by his state police security detail. No one had been found to be infected, he said, but more than 75 troopers, staffers and Pataki himself had begun treatment with antibiotics.
"I honestly believe the likelihood of contamination is very slim, but we're going to have everybody take Cipro as a precaution," he said.
Cipro is an antibiotic used to treat anthrax.
Pataki said the sweep was ordered Monday after his secretary voiced concern about a letter she had received Sept. 25. The governor said the letter contained no threat and was unlikely to be the source of the anthrax.
Suggesting another possibility, Pataki said the troopers in his security detail have been involved in the city's responses to anthrax incidents at the New York offices of NBC and ABC. They could have come into contact with the spores then, he said, and inadvertently carried them back to the office.
NBC staffer infected A 38-year-old staffer at NBC's Nightly News offices in Manhattan contracted an anthrax skin infection after opening a letter later found to contain anthrax spores. The infant son of an ABC News producer caught the same illness after a visit to ABC's New York offices last month. A Florida man is recovering from the inhaled form of the disease, which killed a tabloid editor Oct. 5.
In Washington yesterday, officials said that 23 members of Daschle's staff and five Capitol police officers had "positive nasal swabs," indicating an exposure to anthrax, officials said. Three staffers for Sen. Russell Feingold, a Wisconsin Democrat whose office is next to Daschle's, also tested positive.
None of the Capitol Hill workers showed signs of the anthrax disease, but all were being treated with antibiotics as a precautionary measure, officials said.
Initial tests on the letter sent to Daschle indicate that the anthrax it contained was "professionally made," a senior federal bioterrorism expert said yesterday. But so far, laboratory analysts have said they cannot conclude that the bacteria were "weapons grade," he said.
Important characteristics Medical experts, however, insist that such terms have little or no meaning. What matters, they said, is the virulence, or killing power of the bacteria, which is determined by its genetics; the size of the spore particles, which determines how easily they become airborne; and the bacteria's resistance to antibiotics, which dictates how easily victims can be cured.
So far, according to the Centers for Disease Control and Prevention, those questions have not all been answered. CDC epidemiologist Dr. David Fleming said yesterday that the bacteria in the Daschle letter have been found to respond to all antibiotics, and "that is very good news."
The bioterrorism expert, who would speak only on condition that he not be identified, said investigators have "substantive leads," about where the anthrax originated, although he declined to elaborate. FBI officials have said that the anthrax investigations so far have not turned up any direct links to organized terrorism, but that has not been ruled out.
The FBI has said the letter sent to Daschle's office bears similarities in content and handwriting to another letter, also tainted with anthrax, that was mailed last month to Brokaw.