Washington A letter to Sen. Patrick Leahy was laced with billions of anthrax spores, authorities said, and a mysterious new case of the disease was confirmed in Connecticut.
The most deadly form of the disease appeared in a 94-year-old woman in a rural area southwest of Hartford.
Connecticut Gov. John Rowland said early Wednesday the Centers for Disease Control and Prevention has confirmed the Connecticut case after five sophisticated tests at the hospital and state health laboratory had indicated anthrax.
"It's difficult to explain how the person contracted anthrax," Rowland said Tuesday. "There is no evidence (she) contracted the disease as a result of a criminal act."
The governor said the woman lives in Oxford, a rural community of 9,800 people. Kathy Johnson, the first selectman of Oxford, identified her as Ottillie Lundgren, 94.
"We're continuing to put the pieces of the puzzle together," Rowland told CBS' "The Early Show." He said the woman had no apparent connection to Washington lawmakers or the national media, whose members have been the primary anthrax targets so far.
Rowland said 1,500 Connecticut postal workers are being treated with antibiotics.
In Washington, an FBI microbiologist, speaking only on condition of anonymity, said there were easily billions of anthrax spores in the letter addressed to Leahy. Scientists have said they believe 8,000 to 10,000 spores are enough to infect a person with inhalation anthrax, the most serious form.
An investigator who found the Leahy letter in a trash bag of unopened congressional mail last Friday night could feel powder inside the envelope and 23,000 anthrax spores were detected in a two-minute scientific test of the plastic garbage bag being used to hold the Leahy letter, the FBI microbiologist said.
That letter was postmarked Oct. 9, the same date as a similar anthrax-tainted letter sent to Senate Majority Leader Tom Daschle, which contained a little less than two teaspoons of anthrax.
The Leahy letter still has not been opened as investigators, who already are convinced it contains anthrax, consider the best way to examine its contents without compromising possible evidence on the outside of the letter.
FBI officials believe the letters were sent by the same person, and U.S. Postal Inspectors say they believe that Leahy's simply was quarantined at an offsite facility near Capitol Hill when Congress suspended mail delivery.
Trace amounts of the bacteria were detected in the mail rooms of Sens. Edward Kennedy, D-Mass., and Christopher Dodd, D-Conn., but officials said they were so minute they did not pose a health risk.
Nonetheless, the senators' offices were closed early for Thanksgiving. Officials were to begin sanitizing them.
Police said they suspected the Kennedy and Dodd mail offices were cross-contaminated by anthrax spores from the letters to Daschle and Leahy and that there was no reason for alarm.
"All other tests which were done through Dirksen and Russell (Senate office buildings) were negative, and that's good news for us," Capitol Police Lt. Dan Nichols said.
Officials of the two affected senators' offices hoped to reopen them Monday or Tuesday. Congressional officials are also hoping to resume normal mail delivery next week.
Asked if the Leahy and Daschle letters are the only two with anthrax, Capitol Police spokesman Lt. Dan Nichols said, "That's what we know right now."
U.S. Postal Inspector Dan Mihalko said there is an "extremely high probability" that the Leahy letter initially was misrouted on Oct. 12 to a State Department mail facility in Sterling, Va., where a worker came down with inhalation anthrax. The misrouting could explain why the letter never reached Leahy's office, said Mihalko.
The Leahy letter was found Friday by the FBI and investigators from the Environmental Protection Agency in one of some 630 trash bags of unopened mail intended for Capitol Hill and held since the discovery last month of the letter to Daschle.
The FBI and the Environmental Protection Agency spent nearly a week searching sequestered Capitol Hill mail before they found the Leahy letter. Investigators cut a hole in each bag and tested it for signs of anthrax. About 50 of the bags had at least trace amounts of anthrax spores.
The outside of the Leahy letter appears virtually identical to the Daschle letter and bears the same fictitious "Greendale School" return address, all-capital block letters and other characteristics.