[Study on Reentry Evaluation Mode for Blood Donors Used to be HBV Reactive in Jiangsu Province].

OBJECTIVE: To evaluate the risk of reentry in HBV reactive blood donors and feasibility of HBV reentry strategy. METHODS: HBsAg+ or HBV DNA+ donors who had been quarantined for more than 6 months in Jiangsu Province could propose for reentry application. Blood samples were routinely screened by dual-ELISA for HBsAg, anti-HCV, HIV Ab/Ag, and anti- Treponema pallidum and those non-reactive ones were tested by minipool nucleic acid testing (NAT) for three times. To identify occult HBV donors, samples of NAT non-reactive were further tested by electrochemiluminescence immunoassay (ECLIA) for HBV seromarkers (including HBsAg, HBsAb, HBeAg, HBeAb, and HBcAb). Donors of only 4 ECLIA patterns were accepted to reentry, including all 5 HBV seromarkers negative, anti-HBs only but having history of hepatitis B vaccine injection, HBcAb only, HBsAb+ / HBcAb+ with HBsAb more than 200 IU/L. Additionally, the detection rate of HBV infection was compared between routine screening mode and ECLIA, as well as the reentry qualified rate of HBsAg+ and HBV DNA+ blood donors. RESULTS: From Oct. 2016 to Aug. 2019, a total of 737 HBV reactive donors had applied for reentry, including 667 HBsAg+ reactive and 70 HBV DNA+ reactive donors. Among 3 screening methods, the highest HBV detection rate (43.15%, 318/737) was observed on ECLIA, while only 4.75% (35/737) on ELISA and 3.12% (23/737) on NAT, respectively. Among 4 qualified patterns of HBV serological markers, the highest proportion was found in the all negative group (22.90%, 155/677), followed by the group with HBsAb+ only and history of hepatitis B vaccine injection (19.35%, 131/677), and the median concentration of HBsAb was 237.7 IU/L. The unqualified rate of HBV DNA+ donors was 82.86%, which was significantly higher than 47.98% of HBsAg+ donors. CONCLUSION: Routine screening tests merely based on ELISA and NAT could miss occult HBV donors and may not be sufficient for blood safety. HBsAb concentration and vaccine injection history should be included in the evaluation of HBV reactive donors who intend to apply for reentry. There is a relatively larger residual risk of occult HBV infection in blood donors quarantined for HBV DNA reactive.

[A Sero-epidemiological Study on Transfusion-Transmissible Infectious among Volunteer Blood Donors From 2016 to 2020 in Nanjing].

OBJECTIVE: To investigate the status of transfusion-transmissible infection (TTI) among voluntary blood donors in Nanjing in recent five years, in order to provide data support for the recruitment of blood donors and formulation and updating of blood screening strategies. METHODS: HIV/HBV/HCV/TP serological markers were detected by ELISA in 487 120 blood donors in Nanjing from 2016 to 2020. Confirmatory assay was applied in anti-HIV positive samples by Nanjing Municipal Center for Disease Control and Prevention. The prevalence of TTI was calculated and the trend of disease was analyzed under different demographic groups. RESULTS: The total positive rate of TTI in blood donors was 0.49% (2 411/487 120), in which the overall seroprevalence rate of HBsAg, anti-HCV, anti-HIV and anti-TP was 0.23%, 0.09%, 0.01% and 0.16%, respectively. The overall prevalence of HIV and TP remained relatively steady (P>0.05), whereas HBV and HCV decreased year by year (P<0.05). The prevalence of TTI was higher among people with lower education level, high age group and first-time blood donation. CONCLUSION: The prevalence of TTI among voluntary blood donors in Nanjing is at a low level from 2016 to 2020, but the risk still exists. The recruitment of regular donors and the improvement of blood screening technology can effectively reduce the risk of TTI.

[Analysis of Reasons Causing False Positive of HBsAg Single-ELISA-Reactive in Blood Donors].

OBJECTIVE: To explore the reasons causing the false positive of HBsAg single-ELISA-reactive in blood donors of Jiangsu province so as to provide reference data for the return of blood donors. METHODS: Serological test: HBsAg ELISA parallel detection was performed on 319 444 samples of blood donors from 2014 to 2017; the ECLIA was employed to confirm the single-ELISA-reactive (S/CO≥0.5) samples, the nucleic acid test was used to detect the HBV DNA on the all single-ELISA-reactive samples in 6/8 people mixed/single. Reagent evaluation: the Receiver-Operating-Characteristic curve (ROCC) was drawn by the ECLIA/NAT results as the gold standard, and the diagnostic performance of reagents A and B under different cut-off was evaluated. RESULTS: A total of 227 (0.71‰) single-ELISA-reactive samples were detected among 319 444 blood donors, including 39 cases (17.2%) of positive HBsAg and 12 cases (5.3%) of positive HBV DNA; Under the maximum YI, the COI (1.0) employed by the manufacturer recommendation has a better diagnostic value than laboratory COI (0.5), and the capability of reagent A was better than that of reagent B (AUC: 0.661 vs 0.632; Youden: 0.329 vs 0.297), but the specificity of both reagents was restricted (＜60%). Under the maximum YI, the best cut-off value of reagents A and B were 2.4 and 1.4 COI, respectively. Compared with the cut-off value of manufacturer, the sensitivity of reagents A decreased by 33% and the false positive rate decreased by 60% while the sensitivity of reagent B increased by 140% and the false positive rate increased by 36%, respectively. CONCLUSION: The false positive of HBsAg single-ELISA-reactive in blood donors is caused by the limited specificity of ELISA reagent and the setting of COI values. According to ROCC maximum YI method, the COI can be set as 2.4 COI and (0.5-1.4) COI for reagent A and B to reduce false positive rate.

[Detection of Syphilis Infection among Voluntary Blood Donors from 2010 to 2014 in Chinese Nanjing Area].

OBJECTIVE: To understand the epidemiological characteristics of syphilis infection in blood donors of Chinese Nanjing area, to strengthen control of blood quality and to provide the scientific evidence for working out the strategy of prevention and treatment of syphilis infection. METHODS: Firstly the double antigen sandwich ELISA was carried out according to its instructions, test results showing positive will be examed by double orifice second-round. RESULTS: A total of 362425 blood samples were collected from 2010 to 2014, among them 1277 positive samples were detected. The average rate of syphilis infection was 0.35％. The positive rates of different old years were statistically different（X(2)=265.679,P<0.001）, and the change trend of 5 years was statistically different(X(2)trend=237.928,P<0.001）. Among all age groups in the detection of treponema pallidema(TP), the most amount of positive samples and the lowest positive ratio 0.23% were found in the group 18 to 29 years old. The highest positive ratio was shown in age 50 years old and above. There was statistical different in all age groups(X(2)=361.620,P<0.001）. The positive ratio of the detection of TP was 0.32% in male donors which was lower than that in female donors(0.42%). There was statistical different in all sex groups(X(2)=24.659,P<0.001）. Peasant group had the highest positive ratio(1.07%) in the detection of TP and the student group had the lowest positive ratio(0.19%). There was statistical different in all occupation groups(X(2)=300.198,P<0.001）. Junior and under group had the highest positive ratio(0.59%) in the detection of TP and the undergraduates group has the lowest positive ratio(0.19%). There was statistical different in all education groups(X(2)=241.734,P<0.001）. Through chi-square test and trend test analysis showed that there was statistical different in sex, age, educational level and occupation differences. The tendency of the groups' statistics in 5 years is equally important. CONCLUSION: It is necessary to publicize blood donation information consultation scientifically before blood donation, especially for high-risk population. To ensure blood supply safety, it is important to recruit low-risk blood donors and develop permanent voluntary blood donors for reducing blood waste.

[Infection status of HBV, HCV and HIV in voluntary blood donors of Chinese Nanjing area during 2010-2013].

This study was purposed to understand the infection of HBV, HCV, HIV among the voluntary blood donors and the epidemic trend in infectious population in Chinese Nanjing area, and to guide the mobilization and recruitment of blood donors. A total of 199777 whole blood samples of voluntary blood donors were tested by ELISA, the nucleic acid technology (NAT) combined detection (HBV-DNA, HCV-RNA, HIV-RNA) was added for detection of the samples with HBsAg,anti-HCV, anti-HIV at least unilateral negative donors from June 10, 2010 to June 9, 2013 years, and these statistic data were analyzed. Every HIV reactive sample(HIV-antibody and/or HIV-RNA) was sent to be confirmed in the Centers for Disease Control and Prevention in Nanjing. The results showed that the voluntary donors' infection rate of HBsAg, anti-HCV, anti-HIV were 0.45%, 0.28%, 0.11% respectively; NAT positive rate was 0.07%, 32 cases were confirmed with anti-HIV positive, in which 30 cases were male (6 cases were repeated blood donors) and 2 cases were female, 3 cases were unconfirmed, in which 2 cases were males and 1 case was female. The statistical analysis demonstrated that the difference of unqualitative rate of HBsAg, anti-HCV, anti-HIV was statistically significant between the first-time and repeated blood donors.It is concluded that the positive rate of anti-HCV and anti-HIV displayed a declining trend year by year in Nanjing voluntary blood donation population from June 10,2010 to June 9, 2013 years. The unqualitative rate of HBsAg and NAT increased with the age increasing, while that of anti-HCV, anti-HIV decreased with age increasing. The unqualitative rate of the repeated blood donors is far lower than that of the first-time blood donors. The ELISA positive rate of anti-HIV testing in females is higher than that in males, but the confirmed positive rate of male is significantly higher than that of female. Therefore the consulting skills before donating should be improved, concerning the link of recruiting donors, focusing on strengthening the first-time donors' consultation, evaluating and developing the fixed voluntary blood donors, and vigorously popularizing NAT technology in blood screening to improve the blood safety effectively.