Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

Volume 8, Number 10—October 2002
Bioterrorism-related Anthrax

Bioterrorism-related Anthrax

Surface Sampling Methods for Bacillus anthracis Spore Contamination

Wayne T. Sanderson*Comments to Author , Misty J. Hein*, Lauralynn Taylor*, Brian D. Curwin*, Gregory M. Kinnes*, Teresa A. Seitz*, Tanja Popovic*, Harvey T. Holmes*, Molly E. Kellum*, Sigrid K. McAllister*, David N. Whaley*, Edward A. Tupin†, Timothy Walker†, Jennifer A. Freed†, Dorothy S. Small‡, Brian Klusaritz‡, and John H. Bridges§
Author affiliations: *Centers for Disease Control and Prevention, Atlanta, Georgia, USA; †Agency for Toxic Substances and Disease Registry, Atlanta, Georgia, USA; ‡The IT Corporation, Washington, D.C., USA; §United States Postal Service, Washington, D.C., USA;

Main Article

Table 4

Comparison of Bacillus anthracis spore concentration levels in wet swab, wipe, and HEPA vacuum sock samples, Brentwood Mail Processing and Distribution Center, December 17–19, 2001

HEPA vacuum vs. wet swab HEPA vacuum vs. wipe Wet swab vs. wipe
No. samples 58 58 67
Levelsa agreeb 22 38% 26 45% 24 36%
Negative 10 5 8
Low 1 2 0
Medium 0 8 10
High 11 11 6
Levels disagree 36 62% 32 55% 43 64%
Higher levels 34 HEPA vacuum 23 HEPA vacuum 13 Wet swab
Higher levels 2 Wet swab 9 Wipe 30 Wipe
Kendall’s tau-b 0.58 0.66 0.47
Spearman’s correlation
rs (p value)c 0.73 (<0.0001) 0.81 (<0.0001) 0.52 (<0.0001)

aLevel of B. anthracis (CFU/cm2): negative = 0, low = 01–1.6, medium=1.7–15.5, and high=>15.5.
bTwo samples from the same location agree if they are concordant and are both in the same grouping.
cp value for null hypothesis of zero correlation.

Main Article