Table 4. Mean and standard deviations (SD) of surface swab counts in studied ambulance before and after patient services.

Surface swabs collected from	Before patient services		After patient services		p-value
	Number of samples	Mean±SD cfu/cm2	Number of samples	Mean±SD cfu/cm2
Stethoscope	44	0.8±0.9	44	1.7±1.7	0.002*
Oxygen flow knob	44	0.3±0.5	44	1.6±1.9	0.003*
Long spinal boards	18	0.3±0.4	18	1.0±1.4	0.063W
Stretchers	60	0.2±0.3	60	0.7±1.2	0.010*
Air-flow fins	60	0.6±0.7	60	1.6±1.6	<0.001*
Total	226	0.8±0.7	226	1.3±1.1	<0.001*

* Statistical significance by paired t-test at p=0.050

^WNo statistical significance by Wilcoxon at p=0.050

Remark: No surface swab samples had bacterial counts more than the recommended count (≤5cfu/cm²).