Update: adverse events associated with anthrax prophylaxis among postal employees--New Jersey, New York City, and the District of Columbia metropolitan area, 2001.

Antimicrobial prophylaxis to prevent inhalational anthrax has been recommended for persons potentially exposed to Bacillus anthracis as a result of the recent bioterrorist attacks. During October 26-November 6, 2001, an epidemiologic evaluation to detect adverse events associated with antimicrobial prophylaxis was conducted among 8,424 postal employees who had been offered antimicrobial prophylaxis for 60 days in New Jersey (NJ), New York City (NYC), and one postal facility in the District of Columbia (DC). This report summarizes preliminary results of that evaluation, which found that few employees receiving antimicrobial prophylaxis sought medical attention for symptoms that may have been associated with anaphylaxis. Persons with exposures to B. anthracis related to the bioterrorist attacks should complete the full 60-day course of antimicrobial prophylaxis.