TABLE 2.

Parameters for the environmental limit of detection on fomites

Study authors (reference)	Surface area	Sample concn	Surface seeding	Sampling method	Extraction method	Extraction vol	Total vol	Recovery efficiency (%)	Extraction efficiency (%)	Culture medium	Limit of detection
Hodges et al. (38)	10 cm2	0.2-3,000 CFU/cm2	Inoculated with 0.5 ml spore solution	Macrofoam swab	Vortex in 5 ml PBST for 2 min at 10-s intervals	5 ml		31.7-49.1	93.4	Sheep blood agar	12 CFU/cm2
Rose et al. (59)	25 cm2	2 × 104 CFU/cm2	Inoculated with 0.5 ml spore solution	Cotton swab, macrofoam swab	Vortex in 5 ml PBST for 2 min at 10-s intervals	5 ml	100 μl	41.7 for cotton swab, 43.6 for macrofoam swab	93.9 for cotton swab, 93.4 for macrofoam swab	Trypticase soy agar with 5% sheep blood	20 CFU/cm2a
Brown et al. (15)	25 cm2	100-10,000 CFU/cm2	Dry aerosol deposition	Polyester-rayon blend gauze wipe	Sonication and heat treatment	30 ml	1 ml	35 for stainless steel, 29 for painted wallboard	93	Brain heart infusion agar	90 CFU/cm2 for stainless steel, 105 CFU/cm2 for painted wallboard
Brown et al. (16)	25 cm2	100-10,000 CFU/cm2	Dry aerosol deposition	Rayon swab	Sonication and heat treatment	10 ml	1 ml	41 for stainless steel, 41 for painted wallboard	76	Brain heart infusion agar	1 CFU/cm2 for stainless steel and painted wallboard
Brown et al. (14)	100 cm2	100-10,000 CFU/cm2	Dry aerosol deposition	Vacuum filter sock	Sonication and heat treatment	30 ml	1 ml	29 for stainless steel, 25 for painted wallboard, 28 for carpet, 19 for concrete		Petrifilm aerobic count plate	105 CFU/m2 for stainless steel and carpet, 102 CFU/m2 for painted wallboard, 160 CFU/m2 for concrete
Buttner et al. (20)	1 m2	105 CFU/m2	Inoculated with spore solution	BiSKit—wet/dry	Foam compression	3.3 ml for wet sampling, 16.1 ml for dry sampling	1 ml	11.3 for wet sampling, 18.4 for dry sampling		Trypticase soy agar	42 ± 6 CFU/m2 for wet sampling, 100 ± 10 CFU/m2 for dry sampling

^aThe limit of detection was not recorded in the article and was calculated to be at least 20 CFU/cm².