Significant bacterial contamination risk reduction with the use of diversion pouch.

BACKGROUND: Significant efforts have been made towards bacterial risk minimization by limiting the chance of bacteria entering into collected blood, detecting its presence and eliminating them by pathogen reduction technology. Improved skin disinfection and the use of diversion pouch are effective upstream measures to reduce the risk of bacterial sepsis. Here we report on our experience with the use of blood bags with diversion pouch. MATERIALS AND METHODS: An observational study was performed to compare the bacterial contamination rate for two periods of time, i.e. before and after introduction of diversion pouch into blood bags. The incidence of bacterial contamination was monitored by the existing bacterial surveillance programme using pooled samples from 5 units of random donor platelets underwent aerobic culture in the BacT/ALERT 3D system. RESULTS: Between 1 June 2004 and 31 May 2006 (blood bag without diversion pouch), 50 (0·0213%) out of 234,252 units of random donor platelets were found to have bacteria on culture whereas 15 (0·0057%) isolates out of 262,156 units were found from 1 June 2007 to 31 May 2009 (after diversion pouch was introduced). Overall, there was an 85% reduction in bacterial contaminated risk due to skin flora (P < 0·0001) but an increasing trend of detection of non skin flora such as Streptococcus bovis was noted. CONCLUSION: Integration of diversion pouch into blood bags to divert the first 30 mL blood during blood collection on top of the current skin disinfection protocol can significantly reduce the risk of bacterial contamination.

Value of anaerobic culture in bacterial surveillance program for platelet concentrates.

BACKGROUND: Short-term aerobic bacterial culture (STABC) has been used routinely in Hong Kong since 1998 to reduce bacterial contamination in platelet concentrates (PCs) with good results. With more countries implementing routine aerobic and anaerobic cultures of PCs, a prospective study was conducted to determine the value of anaerobic culture to STABC. STUDY DESIGN AND METHODS: PC tested by STABC was used as control. Twenty milliliters of the PC selected for this study was aliquoted and pooled for 7 days aerobic and anaerobic culture. If the initial culture was positive, samples retrieved from the original PC and their associated components were cultured for confirmation and microbiologic identification. RESULTS: A total of 10,035 PC units (2007 pools) were tested. The confirmed positive rates by aerobic and anaerobic cultures per pool were 3 (0.15%) and 13 (0.65%), respectively, which was equivalent to an increased yield from 0.03 to 0.13 percent of PC if anaerobic culture was added. Of the 10 bacteria detected by anaerobic culture only, 9 were found to be Propionibacterium acnes and the remaining one Peptostreptococcus sp. Their mean detection time from inoculation was 92.16 hours (range, 50.4-124.8 hr). CONCLUSION: Addition of anaerobic culture to our routine STABC would significantly increase the detection rate of bacterial contaminated PC. However, since only slow-growing bacteria were detected, and because their clinical significance was uncertain, it is concluded that there was no clear justification to introduce anaerobic culture locally if 5-day shelf life for PCs was to be maintained.