Table 2.

PCR detection of S. xylosusand results of chemical indicators (CI) and biological indicators (BI) during static–open compared with active–closed VHP exposure

Static–open VHP exposure (7 cycles, involving a total of 28 IVC racks and 17 AHU)
S xylosus PCR analysis of processing equipment	Soiled	Washed	VHP exposed
No. positive/no. tested (%)	23/31 (94%)	6/25 (24%)	17/48 (35%)#
	No. of CI with ≥6 log kill/ no. tested	No. of BI with no growth/ no. tested
Room VHP indicators	21/21 (100%)	7/7 (100%)
Equipment VHP indicators (open end)a	4/4 (100%)	3/3 (100%)
Equipment VHP Indicators (closed end)b	1/18 (6%)	0/8 (0%)
Active–closed VHP exposure (5 cycles, involving 20 IVC racks and 11 AHU)
S xylosus PCR analysis of processing equipment	Soiled	Washed	VHP exposed
No. positive/no. tested (%)	10/10 (100%)	2/12 (17%)	0/12 (0%)d
	No. of CI with ≥6 log kill/ no. tested	No. of BI with no growth/ no. tested
Room VHP indicators	15/15 (100%)	5/5 (100%)
Equipment VHP indicators (sealed)c	18/18 (100%)	3/4 (75%)

^aIndicators placed inside an unsealed hose, or the plenum or manifold's open, uncapped end, or the AHU exhaust prefilter chamber left open.

^bIndicators were placed inside the plenum or manifold's capped end, or the AHU exhaust prefilter chamber left closed.

^cIndicators were placed inside the sealed and connected plenum, manifold, or AHU exhaust prefilter chamber, with the AHU set to the VHP cycle.

^dP = 0.008