The 2001 anthrax attacks, a significant instance of bioterrorism in the United States, unfolded shortly after the September 11th terrorist attacks. Letters containing anthrax spores were sent through the mail, leading to illnesses and fatalities. The attacks highlighted vulnerabilities in public health and national security, prompting a complex investigation and reevaluation of preparedness strategies.
Unfolding the Events
The anthrax attacks began with the mailing of contaminated letters in two distinct waves. The initial set, postmarked September 18, 2001, from Trenton, New Jersey, targeted media outlets in New York City and Florida, including ABC News, CBS News, NBC News, the New York Post, and the National Enquirer. Robert Stevens, a photo editor at American Media, Inc. (AMI) in Florida, became the first known victim, developing symptoms and dying on October 5, 2001.
A second wave of anthrax-laced letters, also postmarked from Trenton, New Jersey, on October 9, 2001, targeted the offices of U.S. Senators Tom Daschle and Patrick Leahy in Washington, D.C. In total, 22 people contracted anthrax, with 5 fatalities. Two postal workers from the Brentwood mail facility in Washington, D.C., were among the deceased, exposed as spores escaped from envelopes during mail processing.
The Nature of the Threat
The biological agent used in the 2001 attacks was Bacillus anthracis, the bacterium responsible for anthrax. The attacks involved its spore form, which is highly resistant to environmental stressors and can remain viable for decades. When inhaled, these spores cause inhalational anthrax, a lethal form of the disease that is almost always fatal without prompt treatment.
The anthrax was identified as the Ames strain, known for its virulence and developed in U.S. government laboratories. Initial reports debated whether the powder was “weaponized” with additives like silica, but subsequent tests indicated it was not intentionally enhanced. The method of delivery, through standard mail envelopes, allowed the spores to become airborne and spread through the postal system.
The Extensive Investigation
The investigation into the 2001 anthrax attacks, code-named “Amerithrax” by the FBI, was extensive and complex. Investigators faced challenges due to the novel nature of a bioterrorism attack and lack of immediate leads. Scientific analysis of the anthrax spores, using advanced genomic and microbiological techniques (microbial forensics), helped trace the anthrax to its origin.
Genetic fingerprinting linked the attack anthrax to a specific liquid suspension of Ames-strain Bacillus anthracis spores, known as RMR 1029, located at the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID) in Fort Detrick, Maryland. This flask was the source of the anthrax used in the letters. The FBI’s investigation ultimately focused on Bruce Ivins, a senior biodefense researcher at USAMRIID, who had access to this particular strain.
Ivins became a focus of the investigation around April 2005. Investigators noted his unusual late-night hours in the lab around the time of the mailings. In July 2008, as federal prosecutors prepared to file criminal charges, Ivins died by suicide. On August 6, 2008, federal prosecutors declared Ivins the sole perpetrator, citing DNA evidence linking the anthrax to a vial in his lab. Despite the FBI’s conclusion and the official case closure in 2010, some controversies and questions persisted regarding the scientific evidence and Ivins’s sole responsibility.
Aftermath and Public Health Response
The anthrax attacks prompted significant public health measures and influenced national biodefense strategies. Officials provided antibiotics to thousands potentially exposed to anthrax. Antibiotics like Cipro were widely distributed, with the Centers for Disease Control and Prevention (CDC) recommending a 60-day course of treatment for exposed individuals. This effort highlighted the complexities of mass dispensing programs.
The United States Postal Service (USPS) implemented extensive mail screening protocols. This included Biohazard Detection Systems (BDS) to detect anthrax DNA in mail processing equipment. Additionally, mail to certain government agencies began undergoing irradiation to kill harmful pathogens.
Beyond the immediate health response, the attacks had a psychological impact, creating public fear and uncertainty about mail safety. The events led to enhanced biodefense capabilities and increased investment in countermeasures against biological threats like anthrax, Ebola, and smallpox. The attacks also prompted re-evaluation of national security measures and integrated public health more centrally into emergency response planning.