【Objective】 To investigate the immune status of blood donors in Yangzhou area after SARS-COV-2 vaccinating. 【Methods】 Among 112 voluntary blood donors from August 29 to September 22, 2021, 111 were vaccinated with SARS-COV-2 vaccine.IgM antibody(by enzyme-linked immunocapture method), IgG antibody(by indirect method of combined immunoassay)and IgG antibody titer were detected. 【Results】 A total of 99.11% (111/112 ) voluntary blood donors were vaccinated, two-shot(n=103), one-shot(n=1) and three-shot (n=7) accounting for 91.96%, 0.89% and 6.25%, respectively.Eighty-eight (78.57%) were positive for IgG antibodies, and 14 (12.5%) were positive for IgM antibodies.No statistically significant difference was found in IgG and IgM positive yielding between males and females (P>0.05). The proportion (0.89%, 1/112) of positive IgM in blood donors with blood type A was significantly lower than that of other blood types (P<0.01). The IgG antibody titer of blood donors maintained rather high level within 6 months after vaccinating.47.66% of the donors presented antibody titer more than 160, and 5.60% had IgM antibody been detected within 1 month after vaccinating. 【Conclusion】 At present, the SARS-COV-2 vaccination effect in China is generally good.Since IgG antibodies cannot be detected after 6 months, it is suggested to perform IgG antibody testing for donors who have completed the second dose for more than 6 months.For those IgG antibody negative, booster shots should be conducted.For donors with high IgG antibody titer, their plasma may be considered to replace with COVID-19 convalescent plasma for the treatment of patients with rapid disease progression, or severe/critically ill patients diagnosed with COVID-19, so as to avoid the risk of COVID-19 re-spreading during convalescent plasma collection in blood centers. For blood donors with positive IgM antibodies, it is recommended to follow up the NAT results to minimize the risk of transmission.

Objective:To investigate the unqualified hepatitis C virus (HCV) detection result of blood donors from the served area of blood institutions.Methods:The data related to HCV markers detected of the first and repeat blood donors were collected from the system of practice comparison for the Chinese mainland blood institutions from 2017 to 2021. The anti-HCV reactive rate and the rates of anti-HCV negative but HCV-RNA reaction and all the relationship between rates and the annual, regional and different blood donors were statistically analyzed.Results:During 2017-2021, the number of anti-HCV reactive per 100 000 blood donors decreased from 444.3 to 250.44 in the served area of 22 blood institutions ( χ2=49.677, P<0.05). The number of HCV RNA detected positive per 100 000 anti-HCV negative increased from 0.69 to 2.05 year by year, but there was no statistical significance ( χ2=0.643, P>0.05). The anti-HCV unqualified rate was significantly different among regions ( χ2=3 260.283, P<0.05). The anti-HCV unqualified rate of the first blood donors was significantly higher than that of the repeated blood donors ( F=130.993, P < 0.05). The annual number of HCV RNA detected positive per 100 000 anti-HCV negative blood samples from donors ranged from 0 to 17.28. Conclusions:The anti-HCV unqualified rate of blood donors in the served area of 22 blood institutions decreased year by year. Compared with repeated blood donors, HCV infection should be emphasized in first-time blood donors. The implementation of HCV RNA test can detect out much more HCV infections and reduce the risk of transfusion transmitted infectious HCV.

【Objective】 To evaluate the effectiveness of rapid initial screening using HBsAg and syphilis reagents of immunochromatography technology before blood donation, and explore the influencing factors. 【Methods】 The pre-donation screening of HBsAg and anti-TP and post-donation blood test results of blood donors in Yangzhou region from January 2020 to June 2023 were retrospectively analyzed. The HBsAg and anti-TP reactive samples by ELISA from January to June 2023 were, retested using colloidal gold immunochromatographic reagents, and the results were compared and analyzed. 【Results】 A total of 200 414 blood donors were screened, among which 781 were HBsAg and anti-TP positive, accounting for 0.39%. A total of 191 717 blood donors successfully donated blood, and 986 were HBsAg and anti-TP positive by ELISA, accounting for 0.51%. 62 HBsAg and 61 anti-TP reactive samples were retested using the initial screening reagent, with 24 HBsAg reactive samples and 26 anti-TP reactive samples, accounting for 38.71% and 42.62% respectively. 14 HBsAg and 6 anti-TP gray area samples were retested, but no reactivity was found.The reactivity rates of 9 samples with HBsAg detection S/CO values greater than 25.0 and 10 samples with anti-TP detection S/CO values greater than 15.0 were all 100%.There was a negative correlation between the reaction intensity (S/CO value) of reactive samples and interpretation time of initial screening reaction. 【Conclusion】 The rapid primary screening of hepatitis B and syphilis with immunochromatography technology among blood donors can effectively improve the quality of blood and the qualification rate of blood after collection. Through targeted training of primary screening staff, the quality of primary screening can be further improved, the rate of missed detection can be reduced, and costs can be saved, thus reducing the risk of transfusion transmitted infection and ensuring the health of blood donors.

Objective:To evaluate the residual risk (RR) of transfusion transmitted HIV (TT-HIV) after the implementation of nucleic acid amplification test (NAT) in blood screening test among blood centers in China.Methods:The data of blood donors and HIV infection markers from 2017 to 2020 were collected from 28 blood centers via the Platform of Comparison of blood establishments Practice in Chinese Mainland. The new infection rate/window period mathematical model was used for two types of blood screening strategies, namely, two rounds ELISA plus individual NAT take turn with pooling NAT (2ELISA+ ID-NAT/MP-NAT) and two ELISA plus one round pooling NAT (2ELISA+ MP-NAT), and the RR of HIV infection was estimated also based on first donors (FDs) and repeated donors (RDs) in different blood donation years. T-test analyses were conducted for comparing TT HIV RR among FDs and RDs in different blood donation years with two blood screening strategies, and the variation trend of RR in HIV test was observed.Results:From 2017 to 2020, the RR of FDs in 2ELISA+ ID-NAT/MP-NAT blood screening strategy was 2.869/10 6 person-year, 3.795/10 6 persons-year, 3.879/10 6 person-year, and 2.890/10 6 person-year respectively. The RR of RDs was 1.797/10 6 person-year, 1.502/10 6 person-year, 1.857/10 6 person-year, and 1.483/10 6 person-year respectively. Significant difference exists between RR of FDs and RDs, with F=9.898 and p<0.05. In 2ELISA+ MP-NAT strategy, the RR of FDs was 3.508/10 6 person-year, 1.868/10 6 person-year, 2.204/10 6 person-year, and 1.765/10 6 person-year respectively. The RR of RDs was 0.948/10 6 person-year, 0.926/10 6 person-year, 0.748/10 6 person-year, and 0.682/10 6 person-year respectively. Statistical difference existed between RR of FDs and RDs, with F=17.126 and P<0.05. There was no significant difference between the RR of FDs in these two strategies with F=3.493 and P>0.05, while there was a difference between the RR of RDs in these two strategies with F=24.516 and P<0.05, and a difference between the RR of total donors (TDs) in these two strategies F=20.216 and P<0.05. Conclusions:The RR of TT HIV significantly decreased after the introduction of NAT into blood test among blood centers in China. There were some differences in the RR of HIV testing among different blood screening strategies. There could be significant differences in the RR of HIV testing among different groups of blood donors. Compared with FDs, RDs is the low risk group for HIV.

【Objective】 To analyze the hepatitis B virus (HBV) infection data of blood donors from 18 domestic blood stations, so as to investigate the HBV infection situation of blood donors. 【Methods】 The positive rate of HBV and its distribution characteristics of regions, the percentage of HBsAg+ ELISA in first-time vs repeated blood donors, and the percentage of HBsAg-/HBV DNA+ blood donors of 18 domestic blood stations during 2017 to 2020 were collected from the Working Platform for Practice Comparison of Blood Centers, and the HBV infection among blood donors were statistically analyzed. 【Results】 From 2017 to 2020, the positive rate of HBV in blood donors among 18 domestic blood stations was 13.48/10 000-144.02/10 000, with the average HBV positive rate in eastern, central and western region at 26.14/10 000, 51.98/10 000 and 41.00/10 000, respectively. The HBsAg+ rate by ELISA among first-time and repeated blood donors was 14.55/10 000-305.39/10 000 vs 1.04/10 000-87.43/10 000 The HBsAg-/HBV DNA+ yield was 1.80/10 000-35.31/10 000. 【Conclusion】 The distribution of HBV infection in blood donors has regional characteristics, and HBV prevalence was low in repeated blood donors. HBsAg ELISA combined with HBV DNA detection can better ensure blood safety.

【Objective】 To learn the production efficient of platelet components among prefecture-level blood stations in China, to provide supporting data for those blood stations to optimize the production mode of platelet components and continuously improve production efficiency and supply capacity. 【Methods】 The data from 2017 to 2020 was obtained from 24 prefecture-level blood stations who were the members of the practice comparison network for blood institutes in China. The collection units of apheresis platelets, the number of dual-collections of apheresis platelets and plasma, the average apheresis units of one platelet apheresis procedure, the discarded rate of apheresis platelets, the amount of expired apheresis platelets and the amount of apheresis platelets issued were collected. For concentrated platelets, the prepared amount of platelet concentrates and the amount of expired platelet concentrates were collected; both the quantity of qualified and issued concentrated platelets were submitted for statistical analysis.The total output and efficiency of platelet components were calculated based on the collected data. 【Results】 The average annual growth rate of apheresis platelets collection in 24 prefecture-level blood stations was 12.23%, accounting for 99.80% of the total platelet output; the average collection unit of one platelets apheresis procedure was 1.75; from 2019 to 2020, only 5 blood stations performed dual-collection of platelet and plasma during one apheresis procedure; the discarded rate of apheresis platelets was 0.28%, of which 0.007% was due to expiration. A total of 1 621.2 therapeutic units of concentrated platelets were prepared, and 13.03% of them was discarded due to the expiration. The production efficiency of platelet components was 97.56%, of which the production efficiency of apheresis platelets was 97.61% and the production efficiency of concentrated platelets was 74.43%. 【Conclusion】 There are large regional differences in the supply capacity of platelet components in prefecture-level blood stations. Apheresis platelets are the main resource of platelet components product, and the collection capacity is increasing over the years with the characteristics of high production efficiency and low expiration scrapping rate. However, the preparation of concentrated platelets are still limited with relatively low production and high expiration discarded rate.

【Objective】 To analyze the basic characteristics of whole blood donors from blood stations before and after the outbreak of COVID-19. 【Methods】 After excluding invalid data, data related to the basic characteristics of whole blood donors collected from 26 blood stations in China during 2018 to 2021 were statistically analyzed, including the trend of total whole blood donors, the number of repeated blood donors, the frequency of blood donation, the average age of donors and the recruitment of first-time blood donors. 【Results】 Affected by the epidemic, 8 out of 14 indicators were with large variations, accounting for 57%. The overall growth rate of total whole blood donors during the epidemic was higher than before the epidemic (P<0.05).The number of repeated blood donors has shown an increased trend, with a higher number during the epidemic than before (P<0.05). The frequency of blood donation was lower during the epidemic than before(P<0.05).Average ages of blood donors and female blood donors fluctuated widely during the epidemic, both higher than those before the epidemic(P<0.05).The donation rate of first-time blood donors <25 years old and ≥25 years old varied widely and irregularly during the epidemic (both P<0.05). The percentage of first-time blood donors fluctuated irregularly during the epidemic, with overall percentage lower than that before the epidemic(P<0.05). 【Conclusion】 Whole blood donors from 26 blood stations increased after the outbreak of COVID-19, and some indicators in certain areas showed significant fluctuations during the epidemic.