Update: Investigation of anthrax associated with intentional exposure and interim public health guidelines, October 2001.

On October 4, 2001, CDC and state and local public health authorities reported a case of inhalational anthrax in Florida. Additional cases of anthrax subsequently have been reported from Florida and New York City. This report updates the findings of these case investigations, which indicate that infections were caused by the intentional release of Bacillus anthracis. This report also includes interim guidelines for postexposure prophylaxis for prevention of inhalational anthrax and other information to assist epidemiologists, clinicians, and laboratorians responding to intentional anthrax exposures.