Pathogen inactivation efficacy of Intercept for enveloped viruses was found to be satisfactory. Mirasol showed satisfactory inactivation efficacy for HIV-1 only. The two selected non-enveloped viruses were not inactivated by both systems. Inactivation efficacy of Intercept was more robust for all bacteria tested at high or low titres.

The NDR donors had a substantially higher rate of anti-HBc reactivity than other blood donors indicating that some with anti-HBc reactivity represent donors with occult HBV. Therefore, the incorporation of an anti-HBc testing for NDR donors could improve blood safety testing for the Korean Red Cross.

Background: The risk of transfusion-transmissible infections (TTIs) of HBV, HCV, and HIV in Korea has been reduced significantly by strengthening the blood safety policies. On the other hand, the risk of TTI still exists due to the diagnostic window period or viral variants. Methods: The residual risks of TTI of HBV, HCV, and HIV were calculated from July 1, 2012 to June 30, 2018 by dividing the data into two year sets. The residual risk was conducted by separating the donors who donated only once and those who donated more than once during each period. Results: In the first two years, the residual risks of HBV, HCV, and HIV were calculated to be 17.54/10 6 , 0.42/10 6 , and 0.30/10 6 respectively. The residual risk of HBV and HCV over the last two years was calculated to be 9.41/10 6 and 0.27/10 6 , showing a tendency to decrease with time. On the other hand, the residual risk of HIV over the last two years was calculated to be 0.29/10 6 , showing no significant difference. The residual risk in the donors who donated only once was higher than that in the donors who donated more than once during each period. Conclusion: The real transfusion-transmitted infection can be different from the estimated residual risk in this study because this study was based on the thesis that all NAT-reactive blood components cause infection. Because the residual risk of HBV is higher than HCV and HIV, it was considered that the safety measures for the HBV need to be improved continuously.

Background: Ever since the Korean Red Cross adopted HCV NAT for blood donor screening in 2005, HCV NAT reactive donors have been identified every year. The identification of the clinical features for these HCV NAT reactive donors may be helpful for the treatment and prevention of HCV infection. Methods: We analyzed HCV NAT reactive samples to examine the distribution of HCV RNA genotypes and the quantitative values of 128 and 47 HCV NAT reactive samples in 2007 and 2017, respectively. Results: The dominant genotype of the HCV NAT reactive donors was 1b showing 50.0% (64/128) in 2007 and 44.7% (21/47) in 2017. The genotype 2a was the second most dominant at 40.6% (52/128) in 2007 and 40.4% (19/47) in 2017. The mean titers of HCV RNA were 3.17×106 IU/mL in 2007 and 2.61×106 IU/mL in 2017. More than 90% of the donors showed a range of more than 1,000 IU/mL for the HCV RNA titer. There was no difference of quantitative values in the different genotypes. Conclusion: In this study, the distribution of HCV RNA genotypes in Korean blood donors showed a similar pattern compared to that of the general population. There was no correlation between the quantitative values and genotypes in the HCV NAT reactive blood donors, and there was no significant variation in the distribution of HCV RNA genotypes of the HCV NAT reactive donors between 2007 and 2017. Yet it is thought that the characteristics of HCV NAT reactive samples in other years have to be analyzed to achieve more significant results.

Background: In 2005, the Korean Red cross introduced mini-pool nucleic acid testing (NAT) for human immunodeficiency virus (HIV) and hepatitis C virus (HCV), which upgraded to individual donation (ID) NAT including HBV in 2012. In this study, we analyzed the trend of HCV infection among blood donors after introduction of NAT by estimating the residual risk (RR) of transfusion transmitted infection (TTI) of HCV. Methods: Donation data from 2003 to 2014 were analyzed using the Blood Information Management System (BIMS). Each donation was tested for antibodies and viral RNA for HCV. Prevalence and incidence rate (IR) among repeat donors were determined. RR was determined using the incidence rate/window period model. Results: During the 12-year period, a total of 29,058,436 donations were screened with 34 HCV NAT yield donations. Calculated RR per million donations for HCV was significantly reduced from 13.41 in the pre-NAT period (2003∼2004) to 0.52 in the post NAT period (2006∼2007) (P＜0.001). Most recently (2013∼2014), RR for HCV with TTI was estimated by 0.16 per million donations (1:6,289,308). Conclusion: RR of TTI with HCV was remarkably decreased since introduction of NAT. However, the prevalence and IR of HCV RNA among first time donors was still high and yield cases were more frequent among repeat donors. Therefore, establishment of a sensitive and accurate screening system and measures for maintaining healthy donors should be considered in order to ensure blood safety.