Anthrax bacteria spread by mail to Argentina and Kenya, and new cases emerged in the United States, as officials worldwide moved to contain what they call a “growing bioterrorist threat.” A postal worker in New Jersey and an assistant to CBS News anchor Dan Rather have tested positive for skin anthrax, as health officials said New York hospitals are being flooded by terrified residents demanding tests for the bacteria. Officials reveal the postal worker had contracted skin anthrax, while a second postal worker is still being tested. The pair worked in Hamilton Township, New Jersey, the site of a sorting office through which two anthrax-filled letters earlier sent to Brokaw and Senate Majority Leader Tom Daschle both passed. Investigators combed through the U.S. Congress buildings searching for traces of anthrax after 31 people tested positive for exposure.