Occult HBV infection (OBI) remains a potential threat for blood safety. The prevalence of OBI was investigated in a blood donation center of Chinese PLA General Hospital to improve HBV blood safety. 229446 samples from blood donors were screened by two different enzyme-linked immunosorbent assay (ELISA) kits. 78 samples were HBV DNA positive among 212134 ELISA nonreactive donor samples. The prevalence of OBI was 0.04% (76/212134). Ten samples of OBI were permitted by the donors\' content for further research, and all of these were below 200IU/mL, and six of these were below 20IU/mL(6/10,60%). Genotype B and genotype C was 20% (2/10) and 80% (8/10), respectively. 16 amino acid mutations were detected in the S region of OBI, included three mutations in MHR region of S. The prevalence of OBI is rare in this donation center. These mutations we found may contribute to the multifactorial occurrence of OBI.

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A small percentage of couples who regularly donated blood in China tested positive for HBsAg. Although it is well known that blood donors can acquire hepatitis B virus (HBV) infection from a chronically infected sexual partner, the prevalence of occult hepatitis B infections (OBIs) among blood donations from partners of HBV-infected chronically infected spouses and the risk to blood safety remain poorly understood. Among 212 763 blood donors, 54 pairs of couples (108 donations) were enrolled because one partner tested positive for HBsAg. Several molecular and serological examinations were conducted. The origin of HBV transmission between sexual partners was investigated further. Also evaluated was the potential risk of HBV infection with OBIs. We identified 10 (10/54, 18.6%) sexual partners of chronically infected HBV donors who were positive for HBV DNA, including five samples (9.3%) with OBIs, of which 3 (3/54, 5.6%, 1 in 70 921 donations) passed the routine blood screening tests. Seven of the 10 HBV-DNA-positive couples contracted the virus possibly through sexual or close contact. Among infected couples, immune escape mutations were observed. A high prevalence of OBIs was found among the partners of chronically infected HBV blood donors, posing a potential threat to blood safety.

At present, many infectious pathogens, especially emerging/re-emerging pathogens, exist in the blood of voluntary blood donors and may be transmitted through blood transfusions. However, most of Chinese blood centers only routinely screen for HBV, HCV, HIV, and syphilis. We employed metagenomic next-generation sequencing (mNGS) to investigate the microbiome in healthy voluntary blood donors to help assess blood safety in China by identifying infectious pathogens presented in donations that could lead to transfusion-acquired infections. We collected 10,720 plasma samples from voluntary blood donors from seven blood centers in different cities during 2012-2018 in China. A total of 562 GB of clean data was obtained. By analyzing the sequencing data, it was found that the most commonly identified bacteria found in the healthy blood were Serratia spp. (5.0176%), Pseudomonas spp. (0.6637%), and Burkholderia spp. (0.5544%). The principal eukaryote were Leishmania spp (1.3723%), Toxoplasma gondii (0.6352%), and Candida dubliniensis (0.1848%). Among viruses, Human Parvovirus B19 (B19V) accounts for the highest proportion (0.1490%), followed by Torque teno midi virus (0.0032%) and Torque teno virus (0.0015%). Since that B19V is a non-negligible threat to blood safety, we evaluated the positive samples for B19V tested by mNGS using quantitative polymerase chain reaction, Sanger sequencing, and phylogenetic analysis to achieve a better understanding of B19V in Chinese blood donors. Subsequently, 9 (0.07%) donations were positive for B19V DNA. The quantitative DNA levels ranged from 5.58 × 102 to 7.24 × 104 IU/ml. The phylogenic analyses showed that prevalent genotypes belonged to the B19-1A subtype, which disclosed previously unknown regional variability in the B19V positivity rate. The investigation revealed that many microbes dwell in the blood of healthy donors, including some pathogens that may be dormant in the blood and only cause disease under specific conditions. Thus, investigating the range and nature of potential pathogens in the qualified donations provided a framework for targeted interventions to help prevent emerging and re-emerging infectious diseases.

BACKGROUND: With the safety of blood transfusion being a major public health concern, the development of a rapid, sensitive, specific, and cost-effective multiplex PCR assay for simultaneous detection of hepatitis B virus(HBV), hepatitis C virus (HCV), hepatitis E virus (HEV), and Treponema pallidum(T. pallidum) in blood is crucial.
METHODS: Five primer pairs and probes were designed towards conserved regions of target genes and used to establish a one-step pentaplex real-time reverse transcription PCR(qRT-PCR) assay for simultaneous detection of HBV, HCV, HEV, T. pallidum, and RNase P(housekeeping gene), providing sample quality check. The clinical performance of the assay was further determined with 2400 blood samples from blood donors and patients in Zhejiang province, and compared the results with commercial singleplex qPCR and serological assays.
RESULTS: The 95% limit of detection(LOD) of HBV, HCV, HEV, and T. pallidum were 7.11 copies/µL, 7.65 copies/µL, 8.45 copies/µL, and 9.06 copies/µL, respectively. Moreover, the assay has good specificity and precision. Compared to the singleplex qPCR assay, the novel assay for detecting HBV, HCV, HEV, and T. pallidum presented 100% clinical sensitivity, specificity, and consistency. Several discrepant results between serological and pentaplex qRT-PCR assays were found. Of 2400 blood samples, there were 2(0.08%) HBsAg positive samples, 3(0.13%) anti-HCV positive samples, 29(1.21%) IgM anti-HEV positive samples and 6(0.25%) anti-T. pallidum positive samples proven negative in nucleic acid detection. 1(0.04%) HBV DNA positive sample and 1(0.04%) HEV RNA positive sample were detected negative by serological testing.
CONCLUSIONS: The developed pentaplex qRT-PCR is the first assay on simultaneous, sensitive, specific, and reproducible detection of HBV, HCV, HEV, T. pallidum, and RNase P in a single tube. It could detect pathogens in blood during the window period of infection and is a good tool for effectively screening blood donors and early clinical diagnosis.

OBJECTIVE: No systematic study has measured the incidence of adverse reactions (ARs) to blood donation at the national level in China before 2019. The objective of this study was to establish an effective reporting system to collect information on ARs to blood donation in China.
METHODS: The status of donor haemovigilance (DHV) in blood collection facilities in China was evaluated, and an online DHV system was established to collect data on ARs to blood donation in July 2019. The definitions of ARs were based on the International Society of Blood Transfusion (ISBT) standards. The prevalence and data quality of ARs from 2019 to 2021 were analysed.
RESULTS: A standard online reporting system has been established for ARs to blood donation. In total, 61, 62 and 81 participating sites were included in this pilot study in 2019, 2020 and 2021, respectively. From July 2019 to December 2021, 21,502 cases of whole-blood-related ARs and 1114 cases of apheresis platelet-related ARs were reported, with an incidence of 3.8‰ and 2.2‰, respectively. Data completeness for key reporting elements improved from 41.7% (15/36) in 2019 to 74.4% (29/39) in 2020. Data quality analysis for the year 2021 yielded similar results as for 2020.
CONCLUSIONS: The construction and continuous improvement of the blood donor safety monitoring system prompted the establishment of the DHV system. Improvements have been made to the DHV system in China, with a significant increase in sentinels and higher data quality.

In recent years, manganese dioxide (MnO2) nanoparticles with unique physicochemical properties have been widely used in many biomedical fields, such as biosensors, contrast agents, tumor therapy, and drug delivery. From these applications, MnO2 nanoparticles have great clinical translation potential. However, by contrast, the in vitro and in vivo biosafety of MnO2 nanoparticles have been deeply and thoroughly clarified for the clinical translation, which hinders their clinical applications. In this work, we deeply investigated the blood safety of MnO2 nanoparticles by conducting a series of in vitro and in vivo experiments. These included the effects of MnO2 nanoparticles on morphology of red blood cells, activation of platelets, coagulation functions, and toxicity of key organs. The obtained results show that these effects displayed a concentration-dependent manner of MnO2 nanoparticles. Different safe concentration ranges could be found in the different experimental index. This study provides important guidance for the specific biomedical applications of MnO2 nanoparticles, greatly accelerating their laboratory development and clinical translation.

OBJECTIVE: To advance blood transfusion safety, the Chinese Haemovigilance Network (CHN) was put into operation in 2018. This report describes the development of the CHN and evaluates its role by analysing reported adverse transfusion reactions (ATRs) from 2018 to 2020.
METHODS: All data in this study were obtained from the CHN online reporting platform. A timeline of CHN development is presented, and the activities of CHN-enrolled facilities are analysed by year. The reported ATRs were analysed in detail for ATR types, blood components involved and adherence to case definition, severity and imputability criteria. Incidence rates were calculated and compared with international examples.
RESULTS: During 2018-2020, a total of 3061 ATRs were reported through the CHN online reporting system. The rate of reported ATRs in all facilities and the 10 highest reporting facilities was 0.7‰ and 1.8‰, respectively. When analysed by year, the incidence rate showed an increasing trend from 2018 to 2020. Allergic (68.2%) and febrile non-haemolytic transfusion reaction (27.1%) were the most common. The vast majority of ATRs (92.0%) were not serious, but serious cases of transfusion-associated circulatory overload, transfusion-associated dyspnoea and hypotensive reaction were common. Most (86.0%) of reported cases were definitely or probably associated with transfusion.
CONCLUSIONS: Under-reporting of ATRs occurs in many Chinese hospitals, but the establishment of CHN has increased ATR recognition and management. More effort will be needed in the future to detect transfusion problems and improve transfusion practice in China.

OBJECTIVE: Safe blood transfusion plays an important role in the prevention of transfusion-transmissible infections, and hepatitis C virus (HCV) infection is one of the major problems associated with this procedure. This meta-analysis aimed to determine the prevalence of HCV infection in Chinese blood donors.
METHODS: The study design of this study is a meta-analysis.
METHODS: Eligible studies were retrieved from PubMed, Embase, China National Knowledge Infrastructure, China Science and Technology Journal Database and Wanfang literature databases from 2010 to 2020. The effect measure was presented as HCV prevalence with a 95% confidence interval (CI). Q test was used to assess the heterogeneity, and the I2 statistics was determined to decide whether a random effects model or a fixed effects model should be used as the pooling method. Subgroup analyses were also conducted.
RESULTS: A total of 62 eligible studies, including 9,007,220 HCV blood donors, were analysed. Of the total blood donors, 35,017 were infected with HCV. The pooled HCV prevalence was 0.415% (95% CI: 0.371-0.458). The subgroup analysis revealed that the prevalence of positivity to anti-HCV antibodies was significantly different in each year (P < 0.05). However, no significant difference was observed in HCV prevalence in terms of sex. Moreover, the prevalence of positivity to anti-HCV was remarkably higher in first-time blood donors than in repeat blood donors (P < 0.05), and the rate of HCV infection among university students was significantly lower than that among soldiers (P < 0.05).
CONCLUSIONS: The rate of HCV infection showed a downward trend from 2010 to 2014, increased in 2015-2016, and finally decreased in 2017-2018. Thus, the prevalence of HCV infection has decreased in Chinese blood donors after comprehensive prevention and treatment.

Most Chinese Blood Centers adopted mini pool (MP) nucleic acid testing (NAT) for HBV screening due to high cost of Individual donation (ID) NAT, and different proportions of MP-reactive but ID-non-reactive donations (MP+/ID-, defined as non-resolved donations) have been observed during daily donor screening process. Some of these non-resolved donations are occult HBV infections (OBIs), which pose potential risk of HBV transmission if they are not deferred. This study is aimed to further analyze these non-resolved donations.
The non-resolved plasma samples were further analyzed by serological tests and various HBV DNA amplification assays including quantitative PCR (qPCR) and nested PCR amplifying the basic core and pre-core promoter regions (BCP/PC; 295 base pairs) and HBsAg (S) region (496 base pairs). Molecular characterizations of HBV DNA+ non-resolved samples were determined by sequencing analysis.
Of 17,226 MPs from 103,356 seronegative blood donations, 98 MPs were detected reactive for HBV. Fifty-six out of these 98 (57.1%) reactive MPs were resolved as HBV DNA+, but the remaining 42 pools (42.9%, 252 donations) were left non-resolved with a high rate (53.2%) of anti-HBc+. Surprisingly, among 42 non-resolved MPs, 17 contained one donation identified as OBIs by alternative NAT assays. Sequence analysis on HBV DNAs extracted from these OBI donations showed some key mutations in the S region that may lead to failure in HBsAg detection and vaccine escape.
A total of 53.2% of the non-resolved donations were anti-HBc+, and OBIs were identified in 40.5% of these non-resolved pools. Therefore, non-resolved donations with anti-HBc+ might pose potential risk for HBV transmission. Our present analysis indicates that anti-HBc testing in non-resolved donations should be used to identify OBIs in order to further increase blood safety in China.