Table 3.
Summary of vacuum and wipe sampling recoveries for each trial.
| Material | Triala | Vacuum recovery (×10c CFU cm−2) |
Wipe recovery (×103 CFU cm−2) |
Relative recoveryb | ANOVAc (p value) | ||
|---|---|---|---|---|---|---|---|
| Mean | Std. dev. | Mean | Std. dev. | ||||
| Carpet | 1 | 20.1 | 9.3 | 51.8 | 13.0 | 0.387 | <0.001 |
| 2 | 26.6 | 8.5 | 41.6 | 21.6 | 0.641 | ||
| 3 | 28.2 | 11.9 | 59.6 | 12.6 | 0.474 | ||
| 4 | 21.8 | 10.5 | 107.7 | 38.7 | 0.202 | ||
| 5 | 12.8 | 2.2 | 84.2 | 29.0 | 0.151 | ||
| Concrete | 1 | 14.4 | 3.6 | 48.1 | 18.9 | 0.299 | <0.001 |
| 2 | 31.8 | 5.5 | 122.6 | 60.5 | 0.259 | ||
| 3 | 74.1 | 38.8 | 59.6 | 12.6 | 1.242 | ||
| 4 | 25.7 | 14.9 | 107.7 | 38.7 | 0.238 | ||
| 5 | 34.7 | 10.6 | 105.3 | 40.5 | 0.330 | ||
| Upholstery | 1 | 18.6 | 4.2 | 80.4 | 32.7 | 0.232 | <0.001 |
| 2 | 7.3 | 2.7 | 68.7 | 27.4 | 0.106 | ||
| 3 | 20.8 | 5.6 | 59.6 | 12.6 | 0.350 | ||
| 4 | 13.9 | 8.6 | 107.7 | 38.7 | 0.129 | ||
| 5 | 3.8 | 3.8 | 108.0 | 41.5 | 0.035 | ||
Bold values indicate trial with the highest recovery, as indicated by Bonferroni post hoc tests, for each material. For carpet trials, no one method demonstrated superior recovery compared to the other methods.
a
Trials are consistent with Table 2, and are as follows: Trial 1, vacuum sock (fast); Trial 2, vacuum sock (slow); Trial 3, 37 mm cassette (MCE); Trial 4, 37 mm cassette (PTFE); Trial 5, forensic filter.
b
Relative recovery = mean vacuum recovery / mean wipe recovery.
c
ANOVA (one-way) conducted on relative recoveries, across trials (methods) yet within each material.