By Stephen M. Silverman
Updated October 12, 2001 01:59 PM

The number of reported cases of anthrax in the United States has jumped to one dozen as of Monday morning. Three new cases — a police officer and two lab technicians involved in an investigation at NBC’s New York headquarters — tested positive for the bacteria, Mayor Rudolph Giuliani said on Sunday. That is not to say that these people have come down with the disease. Nevada officials said four people who may have come into contact with a contaminated letter at a Microsoft office tested negative, while results weren’t known for two others. The 12 people do not include an NBC employee who is taking antibiotics after displaying possible symptoms of the disease, reports the Associated Press. On Friday, NBC moved its evening news program to the “Today” show studio and featured itself as the lead story. Health authorities and federal investigators were swarming around the third-floor offices of “NBC Nightly News” after it was revealed that the assistant to anchor Tom Brokaw had anthrax. The network said she had opened a letter with a powdery substance that was addressed to her boss. “Today we find ourselves in the unusual and unhappy position of reporting on our beloved colleague,” Brokaw said on his broadcast. Monday morning, NBC News reported that a total of five people have been exposed to the disease, at least one more than Giuliani had cited the day before. The anthrax scare began Oct. 4 when it was confirmed that a Florida tabloid editor had contracted the inhaled form of the bacteria. He later died, the first such death in the United States since 1976. Seven other employees of American Media Inc. have tested positive for exposure and are being treated with antibiotics. None have developed the disease. A second round of blood tests for more than 300 of the company’s employees is expected this week. In Washington, Attorney General John Ashcroft said it was premature “to decide whether there is a direct link” to Osama bin Laden’s terrorist network, but “we should consider this potential that it is linked.”