Unsupported conclusions on the Bacillus anthracis spores.

Douglas J. Beecher reported on the methodology that a U.S. Federal Bureau of Investigation laboratory used to identify an intentionally anthrax-contaminated letter(s) among mail collected from a Congressional building or postal facility that serves the U.S. Congress after the incident of contamination that occurred on 15 October 2001 (1). The described sampling strategy and initial screening and analysis methodology using direct plating were reported to be efficient and safe. However, the data supplied in the paper could not be used as evidence for judging the quality of the spores or to support or dismiss conceptions about the presence or absence of spore additives or about the production engineering used to prepare the spores. Furthermore, the type of sampling and analysis data presented in the paper could not be used for extrapolation of ideas concerning spore quality or the method of production. It is possible that Dr. Beecher’s laboratory has performed additional analysis and obtained data that might support such conclusions but that were not included in the paper; if that is the case, it would be more scientifically appropriate to add “unpublished data” in parentheses next to the conclusions he offered concerning the apparent lack of additives, spore quality as reflected in particle size distribution, and the production engineering. In a meeting I attended in September 2006, a presentation was made by a scientist who had worked on samples of anthrax collected from letters involved in the same incident in October 2001; that scientist described the anthrax spore as uncoated but said that it contained an additive that affected the spore’s electrical charges (D. Small, CBRN Counter-Proliferation and Response, Paris, France, 18–20 September 2006; organized by SMi [www.smi-online.co.uk]). It would be of importance for Dr. Beecher to submit data in support of his conclusions in another paper to establish a sound scientific basis for his arguments.