Evaluation of a macrofoam swab protocol for the recovery of Bacillus anthracis spores from a steel surface.

A protocol to recover Bacillus anthracis spores from a steel surface using macrofoam swabs was evaluated for its accuracy, precision, reproducibility, and limit of detection. Macrofoam swabs recovered 31.7 to 49.1% of spores from 10-cm2 steel surfaces with a < or =32.7% coefficient of variation in sampling precision and reproducibility for inocula of > or =38 spores.