USAF MEDICAL READINESS DIVISION HUMAN SYSTEMS DIVISION,

File: aacal_01.txt
Page: 01
Total Pages: 2
SUBJECT:  USAF MEDICAL READINESS DIVISION HUMAN SYSTEMS DIVISION,
                    ANTHRAX DETECTOR PROGRAM

DESCRIPTION:     DISCUSSES THE DEVELOPMENT OF THE ANTHRAX DETECTOR KIT,
                               ENTIRE  DOCUMENT

MEMORANDUM FOR SG 15 JAN 91
              THRU SGH
SUBJECT:    Human  Systems Division {HSD) Anthrax Detector Program . (Yr Query,
              14 JAN 91 )  -  INFORMATION MEMORANDUM
      
      HSD undertook the development of an anthrax (Ax) detector following a
      briefing on 27 Nov 90 on the significance of the Ax threat to Operation DESERT
      SHIELD, the lack of an Army detection capability/program, and their concern
      that Ax could only then be detected by the appearance of sentinel human cases.
      
      The prototype detector consists of two pieces. The "front end"
      detector consists of-an off-the-shelf, sized based, aerosol sampler which can
      discriminate biological from inert particles in the size range of interest and
      the "back end" confirms the biological particles are Ax:
      
      AEROSOL DETECTOR - This unit samples air and measures particles
      (of the size of interest)/volume. The air sample is exposed to ultraviolet.
      light, which will ionize biological agents (with the exception of toxins but
      not inert particles. The sample then passes through capacitor plates to which
      an alternating (to prevent build up of particles) electric field is provided;
      this portion measures charged (e.g. biological) particles per unit volume. The
      Crew Systems Directorate of the Armstrong Laboratory (formerly AAMRL/HE) has
      developed scenarios for Ax-attack to provide detector indications (rate of rise
      of Ax particles, concentration of particles, etc.) of probable Ax attack. This
      detector has been tested under laboratory conditions against the Sterne (non-
      pathogenic] strain of Ax and worked well. An exponential rise above background
      would be used as an indication of biological attack. This unit is not specific
      for Ax, so further confirmatory testing is required. The unit has not
      undergone field testing to date. Within days, 4 units are scheduled to be sent
      to CENTCOM for field testing, including the evaluation of the frequency of
      false positives. A single unit is also being sent to the Army for testing
      against virulent Ax, although results are not expected to differ from those
      using the Sterne strain.
      Ax CONFIRMATION KIT - This kit provides a validated method of
      confirming the presence of Ax.  Five types of tests are in the kit, two of
      which are highly specific for Ax. The latter are performed on an agar plate to
      which sampled material is applied. Part of the plate is then swabbed with a
      bacteriophage specific for Ax. Under the light microscope, areas with Ax show
      a "chain of pearls" (a visual finding) in non-swabbed areas and no growth where
      the bacteriophage has been swabbed killing the organism. Currently
      approximately 4 hours are required to detect low concentration of AX and 2
      hours for more concentrated samples.  The Occupational and Environmental Health
      Directorate of the Armstrong Lab (formerly USAFSAM/RZ  developed the technology
      and has sufficient phage material on hand for 5,000 swabs. It plans to produce
      a limited number of kits until it can arrange for contractor production.
      Efforts are underway to modify the system so that a color change results if Ax
      is present; this has the potential to greatly decrease the time for
      confirmation.