Comparison of the Bact/Alert blood culture system and manual culture method for detection of aerobic and facultative anaerobic bacterial contamination in platelet concentrates

For reducing bacterial contamination of platelets in the medium, PDA has approved the Bact/Alert for screening the platelet units. This study attempts to compare the Bact/Alert system and the manual culture method as far as the length of time in hours of detection is concerned. In this interventional and diagnostic study, 15 platelet units were selected randomly among 1332 units and inoculated with 10 CFU/ml of various bacteria including Streptococci, Serratia marcescens, Enterobacter cloacae, Corynebacterium diphteroid, Staphylococcus aureus and Staphylococcus epidermidis which normally contaminate platelet units. These units together with other platelet units in a blind way were tested by both Bact/Alert system and the manual method. Regarding the short expiration time of platelet units, if the length of time in hours in detection is considered as a basis for comparison, the Bact/Alert system is significantly superior to the manual method. The medium length of time in hours for detecting the aerobic bacteria by Bact/Alert system is 31 +/- 8 hours, compared with the manual method which is 61 +/- 11 hours. This shows that Bact/Alert system is nearly 2 times faster than the manual method. Bact/Alert culture system compared with the manual method is more rapid and accurate for detection of bacterial contamination thereby improving platelet safety. Regarding serious effects of these contaminations on platelet recipients, it is also necessary to try to reduce them by using GMP

[Evaluation of the effect of Virkon disinfectant in reducing bacterial contamination of platelet components]

One of the main steps in reducing bacterial contamination of blood and blood components is the correct use of appropriate disinfectants at blood collection sites and blood processing areas.Virkon is one of the most effective disinfectants consisting of a high percentage of surfactant.The purpose of the present study was to test the bactericidal effect of Virkon on native species of bacteria seen in Iran by selecting a suitable concentration of Virkon. This was an interventional study. 169 samples were taken from laboratory benches, instruments and outer surfaces of blood bags. After the growing bacteria were identified, their CFU/ml was also determined. Later, all the laboratory benches and instruments involved in the preparation of platelet components were disinfected using [1%] Virkon solution. 101 samples were taken from disinfected areas and swabs were plated on to standard bacteriological media and plates were read. 1100 segments from platelet bags were also separated and the platelet contents were plated and any bacterial growth were assessed using quality control department guidelines. Finally, all the data were analyzed using SPSS, Chi-square and Fischer exact test. Out of 169 samples which were plated before disinfection by Virkon, 96 were 56.8% gram positive, 101 were 59.8% gram positive cocci, 159 were 94.8% gram negative b., and 139 were 82.2% gram negative cocci. Out of 101 samples post-disinfected by virkon solution, 25 came out to be 24.8% gram positive b., 17 were 16.8% gram positive cocci, and 6 were 5.9% gram negative b. Out of 1100 segments separated from platelet bags, 4 showed bacterial growth [0.0036%], 2 had gram positive b. growth, and 2 had staph. By using correct concentration of Virkon solution and following the exact manufacture's instruction for use, we were able to observe log reduction in bacterial contamination of the areas where blood components were prepared. The reduction of bacterial contamination in platelet components prepared after disinfection of the working areas by Virkon solution should be emphasized

impact of bar code in gaining the confidence of rejected blood donors to address the questions with a special focus on HIV

To prevent the transmission of HIV through blood transfusion, blood transfusion centers have embarked on deferring high risk prospected donors by pre-donation consultation and screening blood donors to discard contaminated blood units. Since the deferal of high risk blood donors in consultation sessions in Iranian Blood Transfusion Organization plays a major role in the decrease of HIV risk in donated blood units and considering that high risk behaviours which expose people to HIV are usually deemed taboo making them abstain from speaking about, this study aims to evaluate impact of bar code in gaining the confidence of blood donors to address the questions with a special focus on HIV. This study was descriptive. The physicians in blood centers were required to address deferred blood donors with questions about their history of intravenous drug use and unsafe sexual behaviors. Their responses were then reported by a bar-code method as positive or negative. Blood samples of such deferred blood donors were also tested for HIV. SPSS software was finally used for data analysis. Out of 36312 rejected blood donors, 349 [1%] deferred had experienced both unsafe sexual behavior and intravenous drug use, 1735 [4.8%] unsafe sexual behavior, 267 [0.7%] intravenous drug use, and 33961 [93.5%] considered themselves free from the both. Out of the 43 contaminated with HIV, 0% fell in the first group, 1 [0.58%] in the second, 0% in the third, and 42 [1.2%] in the fourth. Since the recognized ways of HIV transmission in Iran are intravenous drug use [in 60.8% of cases] and unsafe sexual behavior [in 7.3% of cases], the high prevalence rate of HIV in rejected blood donors with none of these experiences strengthens the hypothesis that even the use of bar code method can not be effective in assuring them to disclose their confidential information