S205: Remediation Challenges with Bacillus anthracis Spore Contamination

The potential havoc from deliberate release of Bacillus anthracis on the homeland was demonstrated by the 2001 “letter attacks” of office building interiors.  Response to the biological attacks involved experts addressing critical issues such as the extent of the contamination, the best means to decontaminate, and what level of decontamination must be achieved for an acceptable risk level (“how clean is clean enough?”).  As a biological threat, B. anthracis poses major challenges for remediating an attacked site and reducing levels of the pathogen for an acceptable risk.  Because B. anthracis as a spore can tolerate disinfectants, decontamination of the pathogen could be a great challenge requiring alternate strategies for effective pathogen inactivation.  The spore presents challenges to rapid molecular-based detection systems used to assess contamination as well as decontamination effectiveness.  Antibodies developed for B. anthracis detection can react with non-target organisms present in samples and yield false-positive signals.  While PCR provides can provide accurate identification of B. anthracis, sensitivity can be limited by inability to disrupt the spore wall for nucleic acid release as well as the presence of sample materials that interfere with the detection reaction.  Because B. anthracis can cause disease by three exposure routes (inhalation, ingestion, and dermal contact) and could survive in a variety of inhospitable environments (surfaces, soils, waters, and foods), numerous attack scenarios are possible.  Consequently, deriving acceptable risk levels and remediation strategies for the many possible types of attacks is a daunting task.