Collaboration between public health and law enforcement: new paradigms and partnerships for bioterrorism planning and response - Bioterrorism-Related Anthrax

Emerging Infectious Diseases, Oct, 2002 by Jay C. Butler, Mitchell L. Cohen, Cindy R. Friedman, Robert M. Scripp, Craig G. Watz

The biological attacks with powders containing Bacillus anthracis sent through the mail during September and October 2001 led to unprecedented public health and law enforcement investigations, which involved thousands of investigators from federal, state, and local agencies. Following recognition of the first cases of anthrax in Florida in early October 2001, investigators from the Centers for Disease Control and Prevention (CDC) and the Federal Bureau of Investigation (FBI) were mobilized to assist investigators from state and local public health and law enforcement agencies. Although public health and criminal investigations have been conducted in concert in the past, the response to the anthrax attacks required close collaboration because of the immediate and ongoing threat to public safety. We describe the collaborations between CDC and FBI during the investigation of the 2001 anthrax attacks and highlight the challenges and successes of public health and law enforcement collaborations in general.

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Public health and law enforcement agencies become involved in the investigation of a possible bioterrorism event under different circumstances. Such events fall into one of two categories: overt and coven. In the overt event, the perpetrator announces responsibility for something (for example, release of an agent) or the nature of the event reveals itself (i.e., the 1995 sarin attack by the Aum Shinrikyo in the Tokyo subway). In the overt attack, usually law enforcement first detects the event, leads the initial response, and notifies public health officials (Figure 1). If persons are ill or preventive health services are indicated, public health will also become involved in the emergency response.

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In contrast, the covert event is characterized by an unannounced or unrecognized release in which the presence of ill persons may be the first sign of an attack. In the covert attack, criminal intent may not be apparent until some time after illnesses are recognized. This distinction is important for establishing and understanding the partnership between public health and law enforcement. The overt event is clearly a crime, and the site of the incident is a crime scene. As a result, access to the area may be restricted so that evidence can be collected pursuant to the criminal investigation. Under federal statute (Title 18, U.S.C. Section 2332[a]), any threatened use of a disease-causing organism directed at humans, animals, or plants is a crime, regardless of whether the perpetrator actually possesses a disease-causing agent. In addition, as a result of a change in the Bioterrorism Weapons Anti-Terrorism Act contained in the USA PATRIOT Act of 2001 and codified in Title 18 USC Section 175(b), knowingly possessing a biological agent, toxin, or delivery system which cannot be "justified by a prophylactic, protective, bona fide research, or other peaceful purpose" can result in arrest, prosecution, and fines and/or imprisonment for up to 10 years. This new provision shifts the burden of proof onto the person or persons who are in possession of dangerous biological agents to prove they have the material for legitimate purposes.

The covert event may not be initially recognized as an attack, and public health generally first recognizes the problem and leads the initial inquiry (Figure 2). The early response will focus on diagnosis, medical care, and epidemiologic investigation. The intentional and criminal nature of the event may not be immediately evident, and notification of law enforcement may be delayed as a result. A 1985 outbreak of gastroenteritis in Oregon that was caused by a religious cult contaminating multiple salad bars with salmonella was initially thought to be a natural event (1). The crime was only recognized after the cult's leader accused other cult members of the attack and publicly called for an investigation. The subsequent criminal investigation confirmed the role of cult members in the outbreak.

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Microbiologic factors may also provide the first clue of the criminal intent of a disease outbreak. In 1996, an outbreak of gastroenteritis among staff in the laboratory of a large medical center was caused by Shigella dysenteriae type 2, a pathogen that is unusual in the United States (2). An epidemiologic investigation linked infection with eating pastries that had been placed in the laboratory break room. S. dysenteriae type 2 matching the laboratory's stock strain by pulsed-field gel electrophoresis was recovered from ill laboratory workers and from an uneaten pastry. A portion of the laboratory's stock strains was missing, and subsequent criminal investigation identified a disgruntled former laboratory employee as the perpetrator.

The anthrax attacks in September and October 2001 provide examples of both overt and covert events and highlight the different ways that public health and law enforcement agencies become involved in investigating bioterrorist attacks. The first case that was recognized in Florida in early October could have represented a natural event and was initially investigated as a public health issue (3,4). However, law enforcement officials were notified and involved in the initial investigation because of the rarity of inhalational anthrax in the United States (5,6), because B. anthracis has known potential as a biological weapon (7,8), and because of increased vigilance for a possible bioterrorist attack after the events of September 11. Once the intentional nature of the event was made evident by the second suspected case of inhalational anthrax in Florida, law enforcement involvement increased dramatically. The receipt of an envelope containing a threatening letter and B. anthracis at the Hart Senate Office Building on October 15, 2001, required that the site be handled as a crime scene, and the intial role of public health was primarily consequence management and technical assistance to the Federal Bureau of Investigation (FBI) and other law enforcement officials.