Analysis of factors related to ELISA-HBsAg negative and HBV DNA positive blood donors

This report analyzed factors relating to ELISA-HBsAg and Hepatitis B virus (HBV) DNA in blood donors. To provide a reference for an accurate screening model for HBV infection in donated blood, we collected rel-evant information from 124 blood donors testing ELISA-HBsAg negative and HBV DNA positive in 2017, including ELISA-HBsAg Max s/co, gender, age, residence, education level, blood donation record and alanine aminotransferase(ALT) value. Meanwhile, 99 blood donors with the results ELISA-HBsAg negative and HBV DNA negative were randomly selected as control. Univariate logistic analysis was conducted for possible correlation factors, then multivariate logistic regression analysis was performed for statistically significant observation indicators. The results showed that the Ct value of HBV DNA mixed test in the observation group donor was higher than that of HBV DNA single test (P<0.05). If one of the two ELISA-HBsAg s/co values was within the range of 0.259 to 0.304, the chance of HBV DNA positive was increased. Univariate logistic regression analysis showed that ELISA-HBsAg Max s/co, gender, age, blood donation history and ALT value were all risk factors in the observation group. Multivariate logistic regression analysis showed that ELISA-HBsAg Max s/co, (OR=5352.448, P<0.05), age (OR= 4.527, P<0.05) and blood donation history (OR=0.441) were risk factors. The study concluded that ELISA-HBsAg Max s/co, age and number of blood donations are risk factors for ELISA-HBsAg negative and HBV DNA positive blood donors, women or donors under 26 years of age had the lowest risk.     

Description and evaluation of a canine volunteer blood donor program

Human volunteer blood donor programs are commonplace, but the concept of nonhuman animal blood banking is relatively new. Few studies exist regarding efficacy, donor screening, and safety for volunteer companion animals. This retrospective study evaluated a nonprofit, community-based canine volunteer donor program using community blood drives. Of 98 potential donors, 14 were ineligible to donate, including 4 who tested seropositive for blood-borne pathogens. Of 84 donors, 45 were Dog Erythrocyte Antigen (DEA) 1.1 positive and 39 were DEA1.1 negative. Donations totaling 143 included 29 repeat donors (35%). No serious adverse events occurred. Minor adverse events included acute donor reaction (2.8%), hematoma (4.2%), rebleeding (2.1%), and skin irritation (0.7%). Adverse event rates were comparable to data for human blood donations. A substantial fraction of donors donated multiple times, suggesting that volunteer donors and their guardians perceived the donation process to be safe and effective. This article discusses the issue of donor consent and use of the term volunteer. This study indicates that nonprofit, community-based canine volunteer donor programs for animal blood banks can be successful while maintaining high safety standards and ethical treatment of volunteers.     

Description and Evaluation of a Canine Volunteer Blood Donor Program

Human volunteer blood donor programs are commonplace, but the concept of nonhuman animal blood banking is relatively new. Few studies exist regarding efficacy, donor screening, and safety for volunteer companion animals. This retrospective study evaluated a nonprofit, community-based canine volunteer donor program using community blood drives. Of 98 potential donors, 14 were ineligible to donate, including 4 who tested seropositive for blood-borne pathogens. Of 84 donors, 45 were Dog Erythrocyte Antigen (DEA) 1.1 positive and 39 were DEA1.1 negative. Donations totaling 143 included 29 repeat donors (35%). No serious adverse events occurred. Minor adverse events included acute donor reaction (2.8%), hematoma (4.2%), rebleeding (2.1%), and skin irritation (0.7%). Adverse event rates were comparable to data for human blood donations. A substantial fraction of donors donated multiple times, suggesting that volunteer donors and their guardians perceived the donation process to be safe and effective. This article discusses the issue of donor consent and use of the term volunteer. This study indicates that nonprofit, community-based canine volunteer donor programs for animal blood banks can be successful while maintaining high safety standards and ethical treatment of volunteers.     

Seroprevalence and Incidence of hepatitis E in Blood Donors in Upper Austria

Background

In recent years various studies showed, that hepatitis E virus (HEV) is a growing public health problem in many developed countries. Therefore, HEV infections might bear a transmission risk by blood transfusions. The clinical relevance still requires further investigations. The aim of this study was to provide an overview of acute HEV infections in Upper Austrian blood donors as well as a risk estimation of this transfusion-related infection.

Methods and Findings

A total of 58,915 blood donors were tested for HEV RNA using a commercial HEV RT-PCR Kit. 7 of these donors (0.01%) were PCR-positive with normal laboratory parameters in absence of clinical signs of hepatitis. Viral load determined by quantitative real-time PCR showed a HEV nucleic acid concentration of 2,217 293,635 IU/ml. At follow-up testing (2–11 weeks after donation) all blood donors had negative HEV RNA results. Additionally, genotyping was performed by amplification and sequencing of the ORF1 or ORF2 region of the HEV genome. All HEV RNA positive donor samples revealed a genotype 3 isolate. For the antibody screening, anti-HEV IgM and IgG were detected by ELISA. Follow up serological testing revealed that no donor was seropositive for HEV IgM or IgG antibodies at time of donation. Moreover, we verified the prevalence of anti-HEV IgG in 1,203 of the HEV RNA negative tested blood donors. Overall 13.55% showed positive results for anti-HEV IgG.

Conclusions

In the presented study, we investigated HEV infections in blood donations of Upper Austria over 1 year. We concluded that 1 out of 8,416 blood donations is HEV RNA positive. Seroprevalence of anti HEV IgG results in an age-related increase of 13.55%. Therefore, based on this data, we recommend HEV-PCR screening to prevent transmission of hepatitis E virus by transfusion.     

Transfusion medicine and safety

Advances in safety of blood transfusion in clinical practice principally relate to preventing transfusion-transmitted infections (TTI). Epidemiological studies of TTI have resulted in the development, standardization, and implementation of an expanding array of immunoassays employed worldwide in routine screening of blood donated by voluntary blood donors. Exclusion of infected blood and their donors has remarkably reduced the risk of transmitting HBV, HCV, HIV-1/2, and HTLV-I/II infections. Nucleic acid tests (NAT) using enzymatic amplification of viral gene sequences have augmented the risk reduction in “window period” infections that are undetectable by the serological tests. Improved viral safety of transfusion therapy has led us to recognize the risk of bacterial contamination, especially in platelet concentrates stored optimally at room temperature. Besides the current effort devoted to microbial risk reduction, pathogen inactivation technologies promise reduction of the residual risk of known and emerging infectious agents. The clinical effectiveness of the foregoing measures, international harmonization/standardization of practices and procedures, and continued hemovigilance portend safest possible safety in the clinical practice of blood transfusion.     

Retroviral infections transmitted by blood transfusion

Modifications in donor screening and the introduction of laboratory testing of donated blood for anti-HIV-1 and anti-HTLV-I have resulted in a significant reduction in the risks of retroviral infections from blood transfusion. Presently, the American Red Cross detects an average of eight carriers of human immunodeficiency virus, type 1 (HIV-1) per 100,000 otherwise acceptable blood donors (0.008 percent), compared with an average of 35 per 100,000 (0.035 percent) when testing for HIV-1 antibodies began in 1985. Surveillance studies in the United States indicate a small likelihood that HIV-2 carriers will pass current screening procedures and be accepted as blood donors. Even if an HIV-2-infected person were to be accepted as a blood donor, there is a 42-92 percent likelihood that this person's blood would be detected as infective for HIV-2 and excluded because of serological cross-reactions that occur in the EIA for HIV-1 antibodies. During 1989, which was the first year that donated blood was routinely tested for antibodies to human T-lymphotropic virus, type I (HTLV-I) in the United States, approximately nine in 100,000 donors (0.009 percent) were confirmed positive for antibodies to HTLV-I, and their donated blood was excluded. Subsequent testing has revealed that a significant number of these persons whose sera was reactive by the HTLV-I EIA were, in fact, infected by HTLV-II. Epidemiological studies of human retroviral infections (HIV-1, HIV-2, HTLV-I, and HTLV-II) continue to provide important data and direction for improving criteria for qualifying blood donors.     

Epidemiological aspects of hepatitis C virus infection among renal transplant recipients in Central Brazil

An investigation was conducted involving 255 renal transplant recipients in the state of Goiás, Central Brazil, to determine the prevalence of hepatitis C virus (HCV), its risk factors, the genotypes involved, and the level of alanine aminotransferase (ALT) present in the patients. All serum samples were tested for anti-HCV antibodies and HCV RNA. Forty-one patients were anti-HCV and/or HCV RNA positive, resulting in an overall HCV infection prevalence of 16.1% (95% CI: 11.9-21.3). A multivariate analysis of risk factors showed that a history of blood transfusions without anti-HCV screening, the length of time spent on hemodialysis, and renal transplantation before 1994 are all associated with HCV positivity. In HCV-positive patients, only 12.2% had ALT levels above normal. Twenty-eight samples were genotyped as genotype 1, subtypes 1a (62.5%) and 1b (31.3%), and two samples (6.2%) were genotype 3, subtype 3a. These data show a high prevalence of HCV infection and low ALT levels in the studied population. The risk factor analysis findings emphasize the importance of public health strategies such as anti-HCV screening of candidate blood and organ donors, in addition to the stricter adoption of hemodialysis-specific infection control measures. The present study also demonstrates that HCV genotype 1 (subtype 1a) is predominant in this population.     

Experiences in HCV-NAT screening prior to releasing cellular components by the German Red Cross Blood Transfusion Service of Baden-Württemberg.

In this report we present the accumulated data on nucleic acid testing (NAT) for hepatitis C virus (HCV) RNA of blood donations by the Blood Transfusion Service of Baden-Württemberg in the period between March 1997 and March 1999. An extra barcoded blood sample was collected from each donor. Samples were tested by NAT in mini-pools of maximally 96 samples. First-time and repeat donors were tested separately. RT/HCV-PCR was performed with the COBAS HCV Amplicortrade mark, versions 1.0 and 2.0 from Roche Diagnostic Systems.Many modifications have been introduced to the original protocol since the implementation of NAT screening aiming at an increase in the sensitivity and specificity of the assay. NAT positive pools containing serologically positive samples were detected. Initially, reactive pools were identified that could not be confirmed by secondary pooling and single testing procedures. So far, no serologically negative but NAT positive sample has been found.     

New strategies for blood donor screening for hepatitis B virus: nucleic acid testing versus immunoassay methods

Serologic testing for hepatitis B virus (HBV) surface antigen (HBsAg) and antibody to HBV core antigen (anti-HBc) has historically been the foundation of blood screening, while HBV nucleic acid testing (NAT) was recently developed to detect HBsAg-negative, anti-HBc-negative blood units donated during early acute infection. Comparison data on seroconversion panels using HBsAg assays of varying sensitivities and pooled- or single-sample NAT, along with viral load estimates corresponding to HBsAg assay detection limits, have provided information on the theoretical benefits of NAT relative to HBsAg. Model-derived estimates have generally been predictive of the yields of DNA-positive, HBsAg-negative window period blood units detected in a number of studies from Europe, Japan, and the US. Studies indicate that the added benefit of pooled-sample NAT is relatively small in areas of low endemicity, with greater yields in areas highly endemic for HBV. Single-sample NAT would offer more significant early window period closure and could prevent a moderate number of residual HBV transmissions not detected by HBsAg assays; however, no fully automated single-sample HBV NAT systems are currently available.Even single-sample HBV NAT may not substitute for anti-HBc screening, as indicated by studies of donors with isolated anti-HBc who have extremely low DNA levels undetectable by standard single-sample NAT and who have been associated with transfusion-transmitted HBV. Moreover, HBsAg testing may still be needed even in the setting of combined anti-HBc and NAT screening. HBsAg-positive units from donors in the chronic stage of infection may contain very low or intermittently detectable DNA levels that single-sample NAT would miss. Although such donors are usually anti-HBc reactive and would be interdicted by anti-HBc screening, some lack anti-HBc. Extensive parallel testing will be needed to determine whether single-sample NAT in combination with anti-HBc might be sufficient to detect all the infectious donors currently interdicted by HBsAg testing. In countries that do not screen for anti-HBc, HBsAg testing would be the only means of detecting donations from chronically infected individuals with low/intermittently detectable DNA, since even single-donor NAT would not identify these potentially infectious blood units. In the future, the current fully automated HBsAg assays may incorporate significant sensitivity improvements, and automated single-sample HBV NAT may become a reality. Each country will need to develop its blood screening strategy based on HBV endemicity, yields of infectious units detected by different serologic/NAT screening methods, and cost effectiveness of test methods in ensuring blood safety.     

Detection of hepatitis B virus in bone allografts from donors with occult hepatitis B infection

The implementation of nucleic acid testing in donor screening has improved the safety of tissue allografts. Although infectious disease transmission can be considered a rare event, the detection of occult hepatitis B infection remains challenging. The studies concerning this risk are mainly based on testing blood specimens. This work shows the correlation between results of samples obtained from donor blood and the corresponding tissue washing solution. Hepatitis B virus deoxyribonucleic acid was detected both in bone allografts from donors with serological profiles associated to active hepatitis B infection and occult hepatitis B infection. These results suggest that hepatitis B virus seems to concentrate in bone marrow even when a low viral load is present in peripheral blood. Even detection at molecular level is not enough to avoid the risk of hepatitis B virus transmission and a multiparametrical evaluation is required in tissue donor screening. The role of clinicians in recognition and reporting of allograft-associated infections is a major concern for the acquisition of experience to be applied in risk control of disease transmission.     

Analysis and application of NAT in Dongguan blood center more than 10 years

This report reviewed the efficacy of nucleic acid testing (NAT), derived from assaying and measuring data, using a Cobass201 system at the Dongguan blood center from 2008 to 2017. During this period, four blood screening models, each reflecting procedure improvements designed to improve residual risk (RR) assessment were assessed. A total of 716 846 blood donors were screened, detecting 1 395 positive by the mixed pool test, which were finally modified to 900 positive cases, after final detection by the separation-single test: detecting 6 HIV cases, 4 HCV cases and 890 HBV cases with a total positive rate of 1.25%. The lowest result was obtained from the twice administered enzyme-linked immunoassay (ELISA) test,used in conjunction with the single Cobas MPX v2.0 model,with rates of: 1/7 405 for HBV, 1/346 020 for HCV and 1/473 934 for HIV, respectively. NAT positive rate is not affected by different screening models. NAT is a recent detection method which can be used to good effect with ELISA, and is a worth while procedure for promoting blood transfusion safety.     

Screening of Danish blood donors for hepatitis B surface antigen using a third generation technique.

The profit to be gained by testing Danish blood donors for hepatitis B surface antigen (HBsAg) with a third generation technique instead of the currently used immunoelectrophoresis was investigated by additional screening of 48 750 blood units by radioimmunoassay three weeks after donation. Twenty nine units were positive for HBsAg on radioimmunoassay (0.059%). Only six of these were found by immunoelectrophoresis (0.012%). Most of the 23 donors positive on radioimmunoassay and negative on immunoelectrophoresis were healthy carriers of HBsAg (20) or had asymptomatic chronic liver disease (two). One donor had acute hepatitis B. Fifteen of the 23 blood units were transfused. The 15 recipients were monitored biochemically and serologically for up to nine months. One recipient developed fulminant hepatitis B, three developed acute hepatitis B, and one became a healthy carrier of HBsAg. All these patients had received blood from healthy carriers of HBsAg. Two recipients were immunised against HBsAg, and in one patient no seroconversion was observed. The remaining recipients died soon after transfusion or were protected by antibodies to HBsAg that had been present before the transfusion. Testing of Danish blood donors using a third generation technique identified a substantial number of donors positive for HBsAg overlooked by immunoelectrophoresis. Most of these donors were healthy carriers of HBsAg. Blood taken from such carriers is highly infectious when transfused, probably because of the large amount of material transmitted.     

Is it necessary for screening irregular antibodies of blood donors?

To explore the necessity of electronic crossmatching applied to irregular antibodies from blood donors, to ensure blood transfusion safety. Irregular antibody screening was performed on blood samples collected in the Dongguan Blood Center from Apr 17, 2014 to Dec 31, 2017. Primary screening was performed on the Sanquin automatic blood group analyzer by the microcolumn gel method (Sanquin). The positive samples were analyzed again using the salt medium method, polybrene method and micro-column gel method (Diana) for the second screening. If the second screening was positive, it was used to determine irregular antibody specificity (using panel cells) and any irregular antibody titer was detected. A total of 208,004 samples were detected, of which 316 were positive (316/208,004; 0.152%). Among them, 120 alloantibodies (120/135,139; 0.088%) were detected in male donors, which was much lower than in female donors (173/72,865; 0.237%) (P<0.01). A total of 16 kinds of known irregular antibodies and 40 cases of unknown antibody specificity were detected, with 119 cases of IgG type and 197 cases of IgM type, at the ratio of 1.65:1. In female donors, the frequencies of anti-D, anti-E, anti-M and anti-Le^a were significantly higher than in male donors (P<0.01). In married couples, the frequencies of anti-D and anti-E were significantly higher than those unmarried (P<0.05). In minority nationalities, the frequency of anti-M was significantly higher than in the Han nationality (P<0.05). In non-Guangdong donors, the frequencies of anti-D and anti-Le^a were significantly higher than in Guangdong donors. 87.02% of irregular antibody positive donors’ antibody titers were lower than “++”, which was deemed as no serious hazard for clinical transfusion. The study suggests that it is unnecessary to screen for irregular antibodies in blood donors. Male donors from Guangdong may not be required to undergo screening for irregular antibodies, and anti-D and anti-E only identification is also not required to be detected in female donors.     

Comparison of hepatitis B,core, HBc,and hepatitis B antibody,anti HBs,in a presumed low risk donor population

Donors screened by medical social history interview negative for high risk behavior or communicable disease history, but subsequently exhibiting reactive serological markers, emphasize importance of duel safe guarding factors for determining donor suitability. This report examines a relationship between two immunoabsorption assay tests, hepatitis B core (HBc) antibody, a required food and drug administration (FDA) test, and hepatitis B antibody (anti HBs), non-required test. Reactive serology results, 129 cases, 3,581 donors (2008–2012) for HBc as the only initially positive serological marker were subjected to anti HBs testing in this history pre-screened donor population. Enzyme linked immunoabsorption assay kits hepatitis B, core and antibody, were used in this study. All samples were initially tested for human immunodeficiency virus, hepatitis B, and hepatitis C, utilizing nucleic acid testing and antigen antibody immunoabsorption assay. Testing was performed by a FDA-registered CLEA-certified reference laboratory. Samples were deceased donor blood samples and a limited number of pre-mortem samples, separated, stored and analyzed according to manufacturer recommendation and FDA regulations. 129 reactive HBc only samples, were subsequently tested for anti HBs. Of these 129, 94 were found to be reactive for anti HBs. This represented 72 % of samples tested for antibody, a higher percentage than anticipated for a medical history negative, low risk population.     

Occurrence of non-A, non-B post-transfusion hepatitis in heart surgery. Prospective study on the value of the determination of serum alanine aminotransferase and detection of anti-HBc antibodies in blood donors

We studied a group of 64 patients undergoing cardiac surgery for the occurrence of post-transfusion hepatitis during a follow-up period of 5 months. They received blood units (packed red cells in saline-adenine-glucose medium and/or fresh frozen plasma exclusively) from 447 volunteer donors. Post-transfusion hepatitis was identified in 5 patients: 1 patient had cytomegalovirus hepatitis and the remaining 4 cases were defined, by exclusion, as non-A, non-B hepatitis (with prevalence and incidence rates of 80% and 6.25% respectively). We found no statistically significant differences between the numbers of transfused blood product units in patients who developed non-A, non-B hepatitis as compared to those who did not. Our analysis of the predictive effectiveness of alanine aminotransferase and anti-HBc antibodies screening in blood donors to prevent non-A, non-B post-transfusion hepatitis led to the following conclusions: we failed to confirm the association between anti-HBc in blood donors and enhanced risk of non-A, non-B hepatitis in recipients since no case developed among patients receiving blood products from anti-HBc positive donors. So, 20 donors (4.5%) would have been discarded without any reduction of the incidence of non-A, non-B hepatitis. we could not confirm nor exclude the possibility that screening donor blood for elevated alanine aminotransferase levels would have reduced the number of non-A, non-B hepatitis in recipients.     

Transfusion-transmitted diseases other than AIDS and hepatitis.

Although the major diseases transmitted by transfusion today are AIDS and hepatitis, many others also are known. These include CMV, syphilis, Chagas disease, babesiosis, parvovirus B19, malaria, Epstein-Barr infection, and many others that have been reported only once or twice. Reducing the risk of transfusion-transmitted diseases is a problem for donor centers where donor screening and laboratory testing for possible carriers is undertaken. Physicians should be aware that the potential for disease transmission is always present when transfusions are administered.     

FINDRISK questionnaire combined with HbA1c testing as a potential screening strategy for undiagnosed diabetes in a healthy population

Despite the efforts to control the epidemic of diabetes the total number of people living with diabetes is still steadily rising. In order to detect people at risk, cost-effective, convenient, and sensitive screening tools to assess the diabetes risk and to detect undiagnosed type 2 diabetes need to be developed and implemented in the primary care setting. To evaluate the combination of the well established FINDRISK questionnaire and HbA1c testing as a potential screening strategy the data obtained from 671 blood donors were analyzed for a potential correlation with the results of an oral glucose tolerance test. Based on the oral glucose tolerance test, 65 blood donors (9.7%) were newly diagnosed with diabetes, 336 (50.1%) with prediabetes, and 270 (40.2%) had a normal test result. Of the 401 blood donors diagnosed with prediabetes or diabetes 322 (80.3%) had a HbA1c between 5.7% and 6.4% and 27 (6.7%) with a HbA1c of 6.5% or greater. The majority of the blood donors newly diagnosed with diabetes or prediabetes (n=327) had a FINDRISK result of 12 points or higher. ROC analyses confirmed that the optimal cut off levels were for FINDRISK ≥ 12 points and for HbA1c ≥ 5.9%. Thus, a 3-step screening strategy applying the FINDRISK questionnaire followed by HbA1c testing and performing an oral glucose tolerance test on selected individuals could be a cost-saving approach for screening large populations and identifying people at risk for diabetes or undiagnosed diabetes.     

戊肝与丙肝病毒在献血员人群中感染状况的对比研究

采用市售试剂对武汉地区乡村献血员进行血清抗ＨＥＶ与抗ＨＣＶ检测,两者的阳性率分别为５．７４％及９．３５％。在２８８份有ＡＬＴ记录的单采浆献血员中,有近期ＡＬＴ升高史的献浆者抗ＨＥＶ及抗ＨＣＶ检出率分别为１４．０４％及１４．１８％,均显著高于无近期ＡＬＴ升高史的献浆者。对上述标本同时进行多项血清ＨＢＶ标志检测,抗ＨＥＶ阳性及抗ＨＣＶ阳性组献血员多项ＨＢＶ标志检测结果与相应阴性组比较均未见显著的差别。     

Comparison of the indirect immunofluorescent (IFAT), ELISA test and the comercial Chagatek test for anti-Trypanosoma cruzi antibodies detection

Chagas disease is a public health problem in Colombia, particularly in the eastern region. Because of human migration from rural areas to urban centers, the possibility of transfusional transmission becomes increasingly important. However the risk can be minimized by a careful screening of blood donors by means of serological tests. Colombian blood banks use comercial, foreign serological tests for screening for T. cruzi infection. The purpose of the current study was to compare the IFAT and ELISA tests (both use antigen obtained from Colombian strains) with the comercially available Chagatek tests. Sera of blood donors were classified in two groups on the basis of the IFAT: group I, 15 positive patients and group II, 14 negative patients. Sera from each group were tested by the ELISA and Chagatek tests. The ELISA test detected 100% of the patients as positive in group I and 7% (1/14) of patients as positive in group II. The Chagatek test detected 93% (14/15) of the patients as positive in group I and 50% (7/14) in group II. The kappa index for concordance between the ELISA and IFAT tests was 0.93 (95% C.I.: 0.80-1.00); between IFAT and Chagatek 0.43 (95% C.I.: 0.26-0.62), and between ELISA and Chagatek 0.49 (95% C.I.: 0.31-0.67). These results highlighted the importance of using autochtonous Colombian strains as antigens in screening tests for blood donors.