Antimicrobial activity of two techniques for arm skin disinfection of blood donors in Brazil

Chlorhexidine alcohol versus povidone-iodine: The comparative study of skin disinfectants at the blood transfusion centers of Iran

OBJECTIVES

The skin disinfection in the blood donor's arm is a key step to minimize the risk of microbial contamination at blood donation sessions. Current study aimed to compare the efficacy of 2% chlorhexidine gluconate in 70% isopropyl alcohol (CHG/IPA) with povidone-Iodine (PI) at blood transfusion centers (BTCs) of Iran.

MATERIAL AND METHODS

Blood donors were selected to evaluate three commercial CHG/IPA disinfectants (N=300), prior the application at BTCs, and to compare the rate of positive skin cultures between CHG/IPA and PI in 31 BTCs (N=8578). The rate of positivity for PI over a 5-year period was also investigated. After application of a two-step disinfection procedure, the biochemical characteristics were checked in accordance with the conventional bacteriological methods. The Z-test analysis was used to compare the deviation between the positive microbial culture ratios.

RESULT

No donors had a positive culture after disinfection during the evaluation study. There was no difference in the rate of positivity between PI and CHG/IPA after disinfection (P>0.05). The rate of positivity for PI from 2012 to 2017 showed a decreasing trend. The rate of positivity was significantly higher in winter rather than summer (P<0.05).

CONCLUSION

The disinfection efficacy of CHG/IPA was equivalent to that of PI. The 5-year monitoring of PI at BTCs showed that the improvement in the rate of positive skin cultures possibly due to effectiveness of correcting actions.

[Prevention of bacterial risk: pathogen inactivation/detection of bacteria]

Bacterial contamination of blood products remains the most important infectious risk of blood transfusion in 2013. Platelet concentrates (PC) are in cause in the majority of the transfusion reaction due to bacterial contaminations. A lot of prevention methods have been developed over the last 10 years (pre-donation interview, skin decontamination, diversion of the first 30 mL of the donation, leuko-reduction...), they have focused on limiting the contamination of the donations and prevent the bacterial growth in donations and/or in the blood products. These measures were effective and led to significantly reducing the risk of adverse effects associated with bacterial growth. However, every year there are about six accidents (with a high level of imputability) and one death. The reduction of the bacterial risk remains a priority for the French Blood Establishment (EFS). The procedure for skin disinfection is going to be improved in order to further strengthen this crucial step to avoid the contamination of donation. Methods of pathogen inactivation applied to plasma and PC are available in France and their effectiveness is demonstrated on the bacterial risk. Methods for bacterial detection of PC are used in many countries now. Automated culture is the most common. Alternatives are now available in the form of rapid tests able to analyze the PC just before the delivery and avoid false negatives observed with automated culture. Assessments are under way to confirm these benefits in 2013.

[Control of the bacterial risk of transfusion in France in 2013]

Bacterial contamination of blood products (BP) remains the most important infectious risks of blood transfusion in 2013. Platelet concentrates (PC) are the blood products the most at risk, whether CPA or MCPS. In France, the residual risk has been steadily declining since 1994. For the platelets, the frequency of transfusion reaction due to bacterial contamination (TRBC) is now about at one per 50,000 CP distributed. The number of deaths has remained stable since 1994 with one death per year (300,000 distributed CP). The progressive decrease in the number of cases of TRBCs is the result of steady improvement of practices and prevention methods at all stages from collection to the transfusion of BP. But if all these improvements have significantly reduced the incidence of TRBCs, mortality is not changed with the CP and the reduction of this risk is a priority for the French Blood Establishment (EFS). Detection methods of CP contaminated or pathogen inactivation are two approaches available and can provide a significant reduction (for the former) or deletion (for seconds) of the risk of transfused contaminated CP. Currently, the choice is in favor of the detection of bacteria. New detection "rapid tests" methods were added to the panel of candidates and are being evaluated. Inactivation of pathogens remains the safest prospect of eliminating this adverse effect of transfusion. Implementation of one method for bacterial detection is probably a transitional measure.