Recovery efficiencies of anthrax spores and ricin from nonporous or nonabsorbent and porous or absorbent surfaces by a variety of sampling methods*.
The 2001 anthrax letter cases brought into focus the need to establish the most effective environmental sampling procedures. Results are presented from two studies aimed at establishing the best procedures for everyday surfaces likely to be contaminated after the release of environmentally stable bioaggressive agents, as exemplified by anthrax spores and ricin. With anthrax spores, contact plates, with mean retrieval rates of 28-54%, performed better than other methods by a wide margin for flat nonporous, nonabsorbent surfaces. They also proved best on flat porous, absorbent materials, although recoveries were low (<7%). For both agents, dry devices (swabs, wipes, Trace Evidence Collection Filters) had universally poor retrieval efficiencies with no significant differences between them. Among moistened devices (wipes, swabs, and Sample Collection and Recovery Devices), wipes were generally best, albeit with considerable cross-over among individual readings (highest mean recoveries for anthrax spores and ricin 5.5% and 2.5%, respectively, off plastic).
Frawley
Dody A
DA
Biological Defense Research Directorate, Naval Medical Research Center, Silver Spring, MD 20910, USA.
Samaan
Marian N
MN
Bull
Robert L
RL
Robertson
James M
JM
Mateczun
Alfred J
AJ
Turnbull
Peter C B
PC
D000881:Anthrax; D023482:Bioterrorism; D032561:Cotton Fiber; D005554:Forensic Medicine; D005898:Glass; D010969:Plastics; D016062:Porosity; D012276:Ricin; D013170:Spores / Q000302:isolation & purification*; D013499:Surface Properties; D014001:Tin; D014934:Wood
D010969:Plastics; D014001:Tin; D012276:Ricin