Another mail handler diagnosed with anthrax
The US Postal Service is checking hundreds more offices nationwide for anthrax spores.
The moves come after a US State Department mail handler who works far from previous anthrax-infected sites was diagnosed with the inhaled form of the disease.
A co-worker is being watched for infection.
Also, the CIA said that it discovered a trace amount of anthrax in the mail-handling building at its McLean, Virginia, headquarters.
A spokesman described the anthrax as "medically insignificant" but said the building was closed for additional tests.
The circle of infection widened with the diagnosis of the State Department mail supervisor, who worked more than 20 miles from Brentwood, Washington's central mail processing facility. Until Thursday, all those infected in the nation's capital had been tied to this central plant, which handles mail for federal agencies.
The 59-year-old man, hospitalised in guarded condition with inhaled anthrax, worked in Sterling, Virginia, where about 90 percent of the State Department's mail is processed, some of which comes from Brentwood.
Doctors asked him if his job ever took him to Brentwood. "His answer was 'never,'" reported Dr. Ivan Walks, Washington's chief health officer.
Washington health officials asked virtually everyone involved with mail handling to report for antibiotics, and thousands of New York postal workers were prescribed the drugs too, even though further evidence of anthrax has not been found there.
The number of confirmed infections reached 13, all linked to the media or the mail, all in Florida, New York, New Jersey or metropolitan Washington.
Among those with inhalation anthrax, three had died, three were hospitalised and one had recovered.
Another six people have been diagnosed with the highly treatable skin form of the disease.
