Follow-up program for blood donors with unconfirmed screening results reveals a high false-positive rate in Dalian, China.

BACKGROUND: Chinese blood donors with unconfirmed serological and/or molecular screening results are deferred permanently. This study investigated the implementation and performance of a follow-up program aiming to improve the notification and management of deferred donors in Dalian, China. STUDY DESIGN AND METHODS: From January 2013 to February 2018, 411,216 donations were tested for HBsAg, anti-HCV, anti-HIV/HIV antigen, and antibodies to Treponema pallidum. HBV, HCV, and HIV nucleic acid testing (NAT) was performed in mini-pools of six or in individual donations (IDs). Reactive donations were evaluated further with alternative serological assays and ID-NAT re-testing. A follow-up procedure was developed to evaluate a subset of deferred donors that were either potential NAT yield cases, serology non-reactive and NAT non-repeated reactive (NRR), or serology NRR irrespective of NAT result. RESULTS: Serological and molecular routine, plus supplemental testing, identified HBV, HCV, HIV, and TP in 503 (0.12%), 392 (0.09%), 156 (0.04%), and 2041 (0.49%) donations, respectively. Overall, 683 of 4156 (16.4%) eligible donors and 205 donors deferred prior 2013 participated in the program. They included 664 serology NRR and 224 NAT yield cases, and 58.8% repeat donors. All markers combined, follow-up documented false reactivity, primary acute infections, and OBI in 61.9% (550/888), 3.3% (29/888), and 12.8% (114/888) of these donors, respectively. Isolated anti-HBc or anti-HBs reactivity was observed in 22% of cases. CONCLUSION: Follow-up testing refined infection status in 78.0% (693/888) of deferred donors with unconfirmed screening results. This high false-positive rate encouraged to reevaluate the current screening strategies and to consider donor reentry.

The prevalence of human T-cell leukemia virus in blood donors in China.

BACKGROUND: China has not yet incorporated routine human T-lymphotropic virus (HTLV)-1/2 blood donor screening, even though HTLV has been reported in the southeastern coastal region. This study was conducted to investigate the prevalence of HTLV in five major regions across of China. METHODS: From January 2016 to December 2017, blood samples were collected in 20 blood centers located in different regions of China. These samples were screened for HTLV-1/2 antibodies using enzyme-linked immunosorbent assay (ELISA). If the test samples were reactive, the samples were confirmed with a western blot (WB) assay. If the results of WB were indeterminate, the donor was interviewed after a minimum lapse of 8 weeks. All follow-up samples from donors were tested for anti-HTLV-1/2 with ELISA and WB. RESULTS: There were 875,453 donor samples tested for anti-HTLV-1/2 by ELISA. In all, 365 samples tested negative, 22 samples tested positive by WB, and 14 samples with HTLV status undetermined due to being lost to follow-up. The prevalences were 11.09, 5.96, 3.16, 2.88 and 0.98 per 100,000 in Xiamen, Changsha, Beijing, Shenzhen, and Nanjing blood center, respectively. The prevalences were 0 per 100,000 for all 15 other blood centers. There was significant differences in the prevalence of HTLV in different regions of China (p = 0.0011). CONCLUSION: In China, HTLV-1 confirmed positive donors are mainly from southeastern coastal areas. It may be necessary to conduct HTLV screening in these areas to reduce the risk of transfusion-transmitted HTLV.