Combining cleaning and disinfection : an alternative approach for preventing the contamination of blood products

Abstract

Several disinfection products and protocols have been devised to provide safe blood and blood derivatives for transfusion; however, sepsis is still the leading cause of transfusion reaction fatalities due to bacterial and fungal contamination of blood products. This fact raises the question whether disinfection on its own is sufficient for preventing such outcomes and whether cleaning of the arm prior to disinfection can further reduce the amount of skin commensals responsible for the contamination of blood products. In this dissertation, one of the blood donors’ arms was disinfected according to the standard protocol and swabs were taken before and after disinfection (scenario 1). The other arm, was cleaned with a hypoallergenic soap-free and alcohol-free wipe and then disinfected using the same procedure (scenario 2). Swabs from this arm were taken before cleaning, after cleaning and after disinfection. The collected swabs were used to inoculate tryptone soya agar plates which were incubated at a temperature which facilitates bacterial and fungal growth. After incubation, it was noted that more bacterial colonies were isolated than fungal colonies due to the fact that the skin harbours more bacteria than fungi. Most bacteria isolated on those after disinfection plates that failed disinfection were coagulase negative staphylococci and the commonest bacteria identified was Staphylococcus epidermidis. Less fungi were isolated on the after disinfection plates that failed disinfection and these were Penicillium sp. and Cladosporium sp. Resultant colony counts from both scenarios were statistically analysed and it showed that both scenarios resulted in a significant reduction of bacterial colony counts post disinfection; however, the after disinfection plates of scenario 2 had a lower average of colony counts than scenario 1. Cleaning the skin prior disinfection resulted in a significant reduction of bacterial colony count and this led to a higher average of bacterial reduction in scenario 2 than scenario 1. There was no significant difference between the outcomes of both scenarios. However, scenario 2 resulted in more successful bacterial reductions than scenario 1. In conclusion, cleaning the skin prior to disinfection reduces the bacterial load on the skin which makes the disinfection process more effective and reduces the probability of contamination of blood products.