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Analysis of Bacterial Contamination in Blood Bank: Comparison of Two Different Donor Arm Disinfectant
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Bacterial contamination of blood components remains an on-going challenge. In the majority of cases, organisms contaminating the blood components are a part of normal skin flora. Here, we report a case of bacterial contamination of blood units through contaminated donor arm disinfectant. There was a series of reactions due to random donor platelet (RDP) transfusion. The patients had features of septic transfusion reactions. On root cause analysis, spirit swabs used for disinfection of donors' arm were identified as the culprit and presence of Clostridium difficile was established. All the blood components prepared on the dates of implicated RDP units were removed from the stock and we replaced the existing 70% alcohol disinfectant with chlorhexidine-alcohol-based antiseptic rub. Further, no such transfusion reactions were reported. Implementation of good donor arm disinfection technique in addition to the use of blood bags with diversion pouch is proposed to be best preventive strategy for resource-poor settings.
Aim:
A prospective study was undertaken to evaluate the use of 2% (w/v) alcoholic chlorhexidine gluconate (2% AlcCHG) in donor arm preparation, to monitor the contamination rate of blood products after the collection and to find incidence of transfusion associated bacteremia.
Settings and design:
Optimal skin antisepsis of the phlebotomy site is essential to minimize the risk of contamination. Food and Drug Administration (FDA) in India has recommended antisepsis with three-step regimen of spirit-10% povidone iodine-spirit for donor arm antisepsis, but not with chlorhexidine, which is recommended by many other authors.
Material and methods:
A total of 795 donors were studied from July 2011 to January 2012. Spirit-10% povidone iodine-spirit was used for 398 donors and 2% AlcCHG was used for 397 donors with the two-step method for arm antisepsis. Swabs were collected before and after use of antiseptic agents for all the donors. All the blood products collected from donors with growth in post-antisepsis swabs were cultured. A total of 123 various blood products were cultured irrespective of the method and result of antisepsis was observed. A total of seven patients had mild transfusion reaction. The transfused blood products, blood and urine specimen of the patients who had transfusion reaction were also cultured.
Results:
Seven donors out of 398 donors had growth in post-antisepsis swab with spirit-10% povidone iodine-spirit protocol and three donors out of 397 donors had growth in post-antisepsis swab with 2% AlcCHG protocol. All blood products collected from donors who had growth in post-antisepsis swabs when cultured had no growth. There was no contamination of blood products.
Conclusions:
Two percent (w/v) alcoholic chlorhexidine gluconate with two-step protocol can be used as an antiseptic agent for donor arm preparation without considerable cost difference. It is at par with spirit 10% povidone iodine spirit protocol as suggested by FDA in India. There was no reported transfusion associated bacteremia in the study period.
Transfusion associated sepsis cases are encountered occasionally and bacterial transmission remains the major cause. The goal of our study was to compare the efficacy of disinfectants in phlebotomy site preparation. After selection of donor the antecubital fossa area of the arm was disinfected with different types of disinfectants namely sprit (70% isopropyl alcohol), povidone iodine (0.5% w/v available iodine in distilled water), savlon (1.5% v/v chlorhexidine gluconate solution and 3.0% cetrimide solution) and combination of sprit and povidone iodine. Swabs were collected from 20 donors using a sterile forceps, after cleaning with different antiseptic solutions. Swab was streaked on blood agar plate aseptically and the plate was incubated at 37°C for 24 h. Colonies were counted and a single colony was re-cultured by growing on nutrient and Mac-Conkey agar. The biochemical characteristics were determined by performing Gram staining, Motility, Catalase and Oxidase tests. The mean values of colonies were significantly higher with savlon compared to other three solutions. The difference was statistically significant by “t” test (t values 1.7–3.0; P < 0.05). Staphylococcus epidermidis, Staphylococcus sp., Streptococcus sp., Micrococcus sp., Bacillus megaterium and Bacillus cereus were the organisms identified. After completion of bleeding, samples from the bag were aseptically inoculated in aerobic and anaerobic culture bottles to be tested on BacT/Alert system. The bag containing donor’s blood did not show any contamination when three cleanings were carried out using sprit, povidone iodine and spirit respectively.
Skin commensal bacteria account for most septic reactions after apheresis platelet (PLT) transfusion. Consequently, we evaluated the effectiveness of two skin disinfection methods in preventing bacterial contamination of PLT collections.
Three regional blood centers evaluated a one-step 2% chlorhexidine/70% isopropyl alcohol (2% CHX/IPA) skin disinfection method (trial group), while 32 blood centers (control group) continued to use a two-step povidone-iodine (P-I) method. Aerobic quality control bacterial culture results and adverse donor events were compared between April 1, 2009, and December 31, 2009.
The rate of initial positive bacterial cultures was significantly lower in the trial regions compared to control regions in 2009 (143 vs. 321 per million: odds ratio [OR] 0.44, 95% confidence interval [CI] 0.23-0.86]). Trial regions also tended to have lower rates of both true-positive cultures (100 vs. 214 per million: OR 0.47, 95% CI 0.21-1.03) and false-positive (contamination) cultures (43 vs. 96 per million: OR 0.45, 95% CI 0.14-1.49). No differences were seen in the corresponding periods in 2007 and 2008 when all centers used P-I skin preparation. Allergic reactions were reported after 89 of 73,247 apheresis procedures (0.12%) in the trial regions representing a 16-fold increase (OR 15.9, 95% CI 9.9-25.6) compared to control regions.
The 2% CHX/IPA single-step skin swabs are more effective in preventing bacterial contamination of apheresis PLT components than a two-step P-I skin disinfection method and may reduce the risk of septic transfusion reactions. Skin irritation and allergic reactions were more likely among donors in trial regions, but reactions were generally mild and self-limiting.
Optimal skin disinfection ensures blood safety. In this study, efficacies of the two-step skin disinfection methods used at Canadian Blood Services (CBS) and two one-step methods produced by different manufacturers were compared.
In each of the three phases of the study, two methods were compared by disinfection of the antecubital fossae of study subjects. The two-step methods were compared in Phase I: Method A (isopropyl alcohol scrub and iodine tincture ampule) and Method B (isopropyl alcohol and chlorhexidine scrub and isopropyl alcohol and chlorhexidine ampule). In Phases II and III, Method B was compared to two different one-step swab sticks containing isopropyl alcohol and chlorhexidine (Methods C and D). Contact plates were applied on each of the subjects before and after disinfection and incubated at 37 degrees C for 24 hours followed by colony counting.
In 99% of the subjects, colonies per plate were reduced from approximately 60 to less than 10 after disinfection using any method. Method B was superior to Method A (p < 0.05) but was not significantly different from Methods C and D. Method D was implemented for skin disinfection at CBS with no significant effects on blood product contamination. Skin reactions increased from approximately 0.02% to approximately 0.62% after implementation, which were subsequently reduced to approximately 0.04%.
In this study, isopropyl alcohol and chlorhexidine disinfectants were more efficacious than isopropyl alcohol and iodine. There was no difference in efficacy between one-step and two-step procedures or between methods of application. A one-step chlorhexidine and isopropyl alcohol kit has been successfully implemented at CBS.
The aim of the study was to derive a donor arm disinfection technique that was rapid, but with a disinfection efficacy equivalent to a previous "best-practice" technique. This method consisted of a two-stage procedure with an initial application of 70% isopropyl alcohol and then 2% tincture of iodine (IATI). The total time for the IATI method was 2 minutes in duration. A rapid technique (1 min in duration) was needed to obviate potential problems due to increased donor waiting time, had the IATI method been implemented at blood donation sessions.
A direct swabbing and plating technique was used to enumerate bacteria present before and after disinfection. In total, seven methods were evaluated.
The chlorhexidine/alcohol applicator (CAA) disinfection device containing 1.5 mL of 2% chlorhexidine gluconate and 70% isopropyl alcohol (99.91% reduction; confidence limits, 99.55%, 99.98%) was shown to have equivalent disinfection efficacy as the IATI method (99.89% reduction; confidence limits, 99.36%, 99.98%; p = 0.86). Procedural time for the 1.5-mL CAA method was 1 minute thereby avoiding potential problems of increased donor waiting time, inherent in the IATI 2-minute procedure at blood donation sessions.
The 1.5-mL CAA disinfection method offers blood services a rapid and effective donor arm disinfection procedure. In 2006, the 1.5-mL CAA procedure was implemented throughout the entire English blood service for all donations.
Transfusion-associated bacterial infections are a quite frequent collateral effect of administration of platelet concentrates (PC). We carried out a microbiological surveillance of bacterial contamination of apheresis platelet concentrates by studying microbial flora on donors' arms before and after skin disinfection, through blood cultures with the diversion volume and with the PC.
Platelet aphereses were carried out using two Haemonetics MCS+ instruments. Cutaneous swabs were examined by the direct plate technique and blood cultures were performed using Bact/ALERT aerobic bottles. In the 5 years from January 2001 to December 2005 we tested 481 PC.
Cutaneous swabs showed significant bacterial growth in 89% of cases before skin disinfection and in 44% after. None of the blood cultures performed on diversion blood was positive, one (0.2%) PC was positive on the fifth day after collection and the presence of a Staphylococcus epidermidis strain was demonstrated.
Our results suggest that the skin disinfection protocol adopted in our structure is not fully satisfactory. The cultures performed on the PC showed a low prevalence of contamination, and the only positive sample was contaminated by a common skin contaminant (S. epidermidis). The culture became positive on the fifth day after collection, but on the second day the PC had been transfused to a patient, without any adverse reaction. In our experience a culture method using Bact/ALERT aerobic bottles was not able to prevent transfusion of the only contaminated PC identified in this study.
To determine the prevalence of Pseudomonas fluorescens on the arms of blood donors, and to elucidate one possible cause for its predominance (60% of cases during 1980-89) in exogenous post transfusion septicaemia (PTS).
Skin swabs were taken from the arms of 782 blood donors and cultured on to heated blood agar. After incubation, Oxidase reagent and the Gram stain were used to select non-fermentative Gram negative rods, which were then subcultured and identified using the Analytical Profile System (API) 20 NE system.
Non-fermentative Gram negative rods were found on the arms of 11.7% of donors, Pseudomonas spp on 1.0%, and Ps fluorescens on the arms of 0.3% of donors.
This evidence emphasises the absolute requirement for efficient skin cleansing of blood donors' arms to minimise the risk of exogenous PTS.
Because most bacteria isolated from contaminated platelet concentrates are thought to originate from the donor's skin, the efficacy of four methods of skin disinfection was compared.
Contact plates were used for antecubital skin cultures after they were demonstrated to be easier to use and at least as sensitive as a swab system. One antecubital fossa of each subject was disinfected by a standard method, the use of a povidone-iodine swabstick containing 0.75-percent available iodine followed by the use of a povidone-iodine swabstick containing 1-percent available iodine. The other arm was disinfected with either a 70-percent isopropyl alcohol scrub followed by an ampoule of 2-percent iodine tincture (Group 1; n = 126); a green-soap sponge followed by a 70-percent isopropyl alcohol swab, used for donors who are allergic to iodine (Group 2; n = 30); or a 0.5-percent chlorhexidine gluconate and 70-percent isopropyl alcohol sponge followed by an ampoule of 0.5-percent chlorhexidine gluconate and 70-percent isopropyl alcohol (Group 3; n = 40). Contact plate cultures were done before and after disinfection, and colonies counted after a 48-hour 37 degrees C incubation period.
Similar numbers of bacteria grew from both antecubital fossae of the same subject before disinfection (p = 0.71). Compared to the standard povidoneiodine method, isopropyl alcohol and tincture of iodine resulted in significantly less bacterial growth (p < 0.001), the green soap and isopropyl alcohol method resulted in significantly more bacterial growth (p < 0.001), and the chlorhexidine gluconate and isopropyl alcohol method resulted in similar amounts of bacterial growth (p > 0.3).
Isopropyl alcohol scrub followed by iodine tincture is more efficacious than povidone-iodine as measured by contact plate cultures. For donors who are allergic to iodine, chlorhexidine gluconate and isopropyl alcohol is more efficacious than green soap and isopropyl alcohol.
Haemovigilance is a national system of surveillance and alarm, from blood collection to the follow-up of the recipients, gathering and analysing all untoward effects of blood transfusion in order to correct their cause and prevent recurrence. In France haemovigilance was created by law and notification of transfusion incidents is a legal obligation. The haemovigilance network associates local correspondents in each hospital and blood centre with regional co-ordinators and is centralised by the Agence Française du Sang. After 4 years the incident reporting rate is 2.3 per 1,000 allogeneic blood components transfused, justifying for example increased efforts in the prevention of bacteria-associated transfusion reactions, haemolytic transfusion reactions or vascular overload. However, haemovigilance still has to be strenghtened by improved information management or further progress in standardisation from one region to the other. The most important factor of success is collaboration between blood centres and hospitals. Haemovigilance clearly is the ultimate quality indicator of a transfusion service.
Despite improved methods for detecting bacterial contamination of blood products, bacterial sepsis remains a significant risk in blood transfusion. This study was undertaken to investigate whether adopting a different skin disinfection protocol could reduce the rate of bacterial contamination of platelet concentrates.
Two skin disinfection protocols were consecutively used in the routine blood collection setting during two 10-month periods: 0.5% cetrimide/0.05% chlorhexidine solution followed by 70% isopropyl alcohol (first 10-month time-period); and 10% povidone-iodine followed by 70% isopropyl alcohol (second 10-month time-period). The rates of bacterial contamination of platelet concentrates were monitored by using a surveillance programme described previously.
The overall bacterial contamination rate in the first time-period was 0.072%. After introduction of the povidone-iodine and isopropyl alcohol protocol, the bacterial contamination rate decreased to 0.042% (relative risk reduction: -0.42; 95% confidence interval, -0.12 to -0.61, P= 0.009). There were no differences in the types of micro-organisms identified (P = 0.7).
Skin disinfection by povidone-iodine and isopropyl alcohol is more effective than that by cetrimide/chorhexidine and isopropyl alcohol in reducing venepuncture-associated contamination of platelet concentrates by skin flora. Our data indicate that the disinfection protocol should be used on a routine basis and such implementation should translate into a significant improvement in blood safety to patients receiving platelet transfusion.
Current risks of transfusiontransmitted agents: a review. Archives of pathology & laboratory medicine
- S L Stramer
Stramer, S. L. (2007). Current risks of transfusiontransmitted agents: a review. Archives of pathology
& laboratory medicine, 131(5), 702-707.
& Bacthem Group the French Haemovigilance Network
- P Perez
- L R Salmi
- G Folléa
- J L Schmit
- B De Barbeyrac
- P Sudre
Perez, P., Salmi, L. R., Folléa, G., Schmit, J. L., De
Barbeyrac, B., Sudre, P.,... & Bacthem Group the
French
Haemovigilance
Network.
(2001).
- C P Mcdonald
McDonald,
C.
P.
(2011).
the English National
Blood
Service. Transfusion
Medicine
and
Hemotherapy, 38(4), 255-258.