The US capitol bioterrorism anthrax exposures: clinical epidemiological and immunological characteristics.

BACKGROUND: Bioterrorism-related anthrax exposures occurred at the US Capitol in 2001. Exposed individuals received antibiotics and anthrax vaccine adsorbed immunization. METHODS: A prospective longitudinal study of 124 subjects--stratified on the basis of spore exposure, nasopharyngeal culture results, and immunization status from inside and outside an epidemiologically defined exposure zone--was performed to describe clinical outcome and immune responses after Bacillus anthracis exposure. Antibody and cell-mediated immune (CMI) responses to protective antigen (PA) and lethal factor were assayed by enzyme-linked immunosorbent assay and fluorescence-activated cell sorting. RESULTS: Antibody and CMI dose-exposure responses, albeit generally of low magnitude, were seen for unimmunized subjects from inside, within the perimeter, and outside the exposure zone and in nonexposed control subjects. Anti-PA antibody and CMI responses were detected in 94% and 86% of immunized subjects. No associations were seen between symptoms and exposure levels or immune responses. CONCLUSIONS: Anthrax spores primed cellular and possibly antibody immune responses in a dose-dependent manner and may have enhanced vaccine boost and recall responses. Immune responses were detected inside the perimeter and outside the exposure zone, which implies more-extensive spore exposure than was predicted. Despite postexposure prophylaxis with antibiotics, inhalation of B. anthracis spores resulted in stimulation of the immune system and possibly subclinical infection, and the greater the exposure, the more complete the immune response. The significance of low-level exposure should not be underestimated.

Anthrax attack at the United States Capitol. Front line thoughts.

One great fear was realized on October 15, 2001 when United States citizens witnessed firsthand the unprecedented release of anthrax into a community. Although the office of the Attending Physician to Congress had been preparing for such an unthinkable act, lessons were learned as the events unfolded. The following is a summary of the findings: Preparation, planning, and frequent review of bioterrorism response procedures are essential. Effective communication remains the key to successful team performance. Briefings conducted daily and on an as needed basis shape the progress and performance of the team members. Electronic mail may not necessarily be the most effective way to disseminate critical information because not everyone can access the Internet outside of the work environment. Setting up a call center for answering client's questions is crucial. Clients potentially exposed to anthrax should be evacuated from the immediate area. Testing is not indicated for everyone, only those in the immediate areas. Allow health care personnel to decide whom should be tested. Such health care decisions must not be made based on anxiety or expediency. A data collection template should be set up in advance. This template should include, at least, the following: name, date of birth, social security number, the physical location of where the client might have been exposed, antibiotics administered and dosage, test results, and home and work phone number. This should be networked so a group can access and update data in real time. If the occupational health clinic has its own pharmacy, have a pill counter available to help with antibiotic distribution. The team should meet several times daily to ensure dissemination of a reliable and consistent message to the clients. Team members should be prepared to review the medical aspects of anthrax with clients on a frequent basis. A website with updated information might prove helpful for those with Internet access. This experience provided a unique opportunity for the Office of the Attending Physician to Congress to put its bioterrorism plan into action. Nothing substitutes for preparedness. Communication was the most important tool because it kept the team informed and focused on the mission at hand. It behooves all occupational health nurses to begin preparing for future acts as extraordinary as the anthrax attack that occurred on October 15, 2001.