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Candotti D, Laperche S. Hepatitis B Virus Blood Screening: Need for Reappraisal of Blood Safety Measures? Front Med (Lausanne) 2018. [PMID: 29515997 PMCID: PMC5826332 DOI: 10.3389/fmed.2018.00029] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Over the past decades, the risk of HBV transfusion–transmission has been steadily reduced through the recruitment of volunteer donors, the selection of donors based on risk-behavior evaluation, the development of increasingly more sensitive hepatitis B antigen (HBsAg) assays, the use of hepatitis B core antibody (anti-HBc) screening in some low-endemic countries, and the recent implementation of HBV nucleic acid testing (NAT). Despite this accumulation of blood safety measures, the desirable zero risk goal has yet to be achieved. The residual risk of HBV transfusion–transmission appears associated with the preseroconversion window period and occult HBV infection characterized by the absence of detectable HBsAg and extremely low levels of HBV DNA. Infected donations tested false-negative with serology and/or NAT still persist and derived blood components were shown to transmit the virus, although rarely. Questions regarding the apparent redundancy of some safety measures prompted debates on how to reduce the cost of HBV blood screening. In particular, accumulating data strongly suggests that HBsAg testing may add little, if any HBV risk reduction value when HBV NAT and anti-HBc screening also apply. Absence or minimal acceptable infectious risk needs to be assessed before considering discontinuing HBsAg. Nevertheless, HBsAg remains essential in high-endemic settings where anti-HBc testing cannot be implemented without compromising blood availability. HBV screening strategy should be decided according to local epidemiology, estimate of the infectious risk, and resources.
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Affiliation(s)
- Daniel Candotti
- Department of Blood-Transmitted Pathogens, National Transfusion Infectious Risk Reference Laboratory, National Institute of Blood Transfusion, Paris, France
| | - Syria Laperche
- Department of Blood-Transmitted Pathogens, National Transfusion Infectious Risk Reference Laboratory, National Institute of Blood Transfusion, Paris, France
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Seed CR. Value of retaining HBsAg donor screening where HBV NAT and anti-HBc donor screening apply. ACTA ACUST UNITED AC 2017. [DOI: 10.1111/voxs.12368] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- C. R. Seed
- Australian Red Cross Blood Service; Perth Australia
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Seed CR, Kiely P. A method for estimating the residual risk of transfusion-transmitted HBV infection associated with occult hepatitis B virus infection in a donor population without universal anti-HBc screening. Vox Sang 2013; 105:290-8. [DOI: 10.1111/vox.12060] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 04/18/2013] [Accepted: 05/03/2013] [Indexed: 12/30/2022]
Affiliation(s)
- C. R. Seed
- Australian Red Cross Blood Service; Melbourne; Vic.; Australia
| | - P. Kiely
- Australian Red Cross Blood Service; Perth; WA; Australia
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Kupek E. Residual Risk of Hepatitis-B-Infected Blood Donations: Estimation Methods and Perspectives. ACTA ACUST UNITED AC 2013. [DOI: 10.5402/2013/839896] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Despite a considerable reduction of the risk of HBV-infected blood donation entering blood supply (residual risk) due to improved screening by HBV NAT in the developed countries, the bulk of the people with HBV living in the developing countries still needs to be screened by serologic tests such as HBsAg and anti-HBc. Many of these countries lack resources for implementing NAT and are likely to remain so in the next decade or longer, thus depending on the HBV residual risk monitoring based on serologic testing and corresponding estimation methods. This paper reviews main HBV residual risk findings worldwide and the methods based on serology used for their calculation with repeat donors, as well as their extension to the first-time donors. Two artificial datasets with high (4.36%) and low (0.48%) HBV prevalence were generated to test the performance of five methods: the original incidence/window-period model based solely on HBsAg, its modification by Soldan in 2003, the Müller-Breitkreutz model, the HBsAg yield model, and its extension to include anti-HBc seroconversions within a year. The last model was closest to the true values of residual risk and had smallest variation of the estimates in both high and low prevalence data. It may be used for residual risk evaluation in relatively small samples, such as regional blood banks data.
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Affiliation(s)
- Emil Kupek
- Department of Public Health/CCS, Universidade Federal de Santa Catarina, 88040-900 Florianopolis, SC, Brazil
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Servant-Delmas A, Chuteau C, Lefort C, Piquet Y, Chevaleyre S, Betbeze V, Delhoume M, Hantz S, Alain S, Laperche S. Two cases of transfusion-transmitted hepatitis B virus (HBV) infection in a low-endemic country before implementation of HBV nucleic acid testing. Transfusion 2012; 53:291-6. [PMID: 22671296 DOI: 10.1111/j.1537-2995.2012.03736.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
BACKGROUND The risk of hepatitis B virus (HBV) transmission by transfusion is higher than that of other blood-borne viruses. In France, before the introduction of HBV nucleic acid testing (NAT) in 2010, blood donations were tested for hepatitis B surface antigen (HBsAg) and antibodies against hepatitis B core antigen, and the residual risk of HBV transfusion related to preseroconversion acute phase was estimated at 0.54 per million donations. The additional value of the implementation of a highly sensitive HBV NAT to prevent such transmissions is discussed. STUDY DESIGN AND METHODS Two lookback investigations based on HBV seroconversion of repeat donors were performed. Donors and recipients were followed up in multiple samples that were tested for HBV serologic and molecular markers. RESULTS The recipients have shown posttransfusion HBsAg seroconversion. The archived samples from the implicated donations were positive for HBV DNA at extremely low viral load in both cases. HBV isolates from donors and recipients of each case were organized in the same cluster with 100% identities into Genotypes A2 and B4, respectively. One recipient spontaneously recovered from infection while the second was successfully treated. CONCLUSION The present cases highlight the importance of introducing highly sensitive HBV NAT to prevent transmission. Moreover, the lookback studies based on appropriate molecular and serologic investigations of patients transfused with previous donations from newly identified HBV-infected repeat donors offer the opportunity to treat a recently infected recipient.
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Affiliation(s)
- Annabelle Servant-Delmas
- Laboratoire d'Expertise en Virologie, Centre National de Référence des Hépatites Virales B et C et du VIH en Transfusion, Institut National de la Transfusion Sanguine, Paris, France
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Abstract
PURPOSE OF REVIEW The availability of hepatitis B virus (HBV) nucleic acid testing (NAT) for donor blood screening led to its implementation in low prevalence and high prevalence countries. Genomic detection was a substantial addition to HBV surface protein (HBsAg) screening by detecting window period infections and 'occult' HBV infections (OBIs), characterized by undetectable HBsAg, low viral load and presence of serological markers (anti-HBc and/or anti-HBs). OBIs are the result of multiple, poorly understood mechanisms including incomplete immune control mutations of the HBsAg antigenic determinants; abnormal expression of S gene; and inhibition of genome transcription. Infectivity for the recipient is high for window period blood and relatively low for OBIs. RECENT FINDINGS The number of cases identified by NAT ranges between 1 : 1000 and 1 : 50 000, depending on epidemiology and assay sensitivity whether NAT is implemented in individual donations or pools of samples. OBI donors are generally older than 45 years except in Africa, carry very low viral load (median 11-25 IU/ml) and have normal alanine transaminase levels. Cases carrying anti-HBc alone are more infectious than those with low level of anti-HBs. Evidence of HBsAg escape mutants that are undetected by commercial assays has been published. Inhibition of HBsAg mRNA production and export are potential mechanisms of OBI occurrence. SUMMARY HBV blood safety is improved by NAT for HBV DNA when applied to individual donations. Until the sensitivity of NAT is improved, both this method and HBsAg screening are needed to eliminate potentially infectious blood donations. Occult HBV characterization clarifies new facets of HBV natural history.
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O'Brien SF, Zou S, Laperche S, Brant LJ, Seed CR, Kleinman SH. Surveillance of transfusion-transmissible infections comparison of systems in five developed countries. Transfus Med Rev 2011; 26:38-57. [PMID: 21944935 PMCID: PMC7134890 DOI: 10.1016/j.tmrv.2011.07.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Most industrialized countries maintain surveillance programs for monitoring transmissible infection in blood donations, revising approaches to methodology and risk assessment as new threats emerge. A comparison of programs in the United States, Canada, France, the UK, and Australia indicates that they have similar function, although the structure of blood programs vary as does the extent and nature of formal ties with public health. The emergence of HIV in the late 1970s and early 1980s was key in recognizing that surveillance systems specific to blood transfusion were essential. Hence, most industrialized countries monitor transfusion-transmissible infections in donors and evaluate the impact of new testing and of predonation screening strategies. Emerging infections since HIV have had different transmission pathways and challenged blood programs to draw upon resources for a rapid and effective response, with recognition that the original focus on sexual/drug-related risk of HIV and hepatitis was inadequate. The focus of surveillance programs on new and emerging pathogens fulfills a key role in risk assessment and policy formulation. The precise nature of such activities varies by country because of the structure of the blood programs and surveillance systems, the strategic focus of the blood programs, and the epidemiology of disease in each country.
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Affiliation(s)
- Sheila F O'Brien
- National Epidemiology and Surveillance, Canadian Blood Services, 1800 Alta Vista Drive, Ottawa, Ontario, Canada K1G 4J5. sheila.o'
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Niederhauser C. Reducing the risk of hepatitis B virus transfusion-transmitted infection. J Blood Med 2011; 2:91-102. [PMID: 22287868 PMCID: PMC3262354 DOI: 10.2147/jbm.s12899] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Indexed: 12/28/2022] Open
Abstract
Before 1970, approximately 6% of multi-transfused recipients acquired a transfusion-transmitted Hepatitis B virus (HBV) infection. The safety improvements since then have been tremendous. From a level of a few infections per 1000 donations, the risk today, depending on the screening algorithm and additional measurements performed, has decreased to around 1:500,000 to 1:1,000,000, an improvement greater than 1000-fold compared to 50 years ago. This enormous gain in safety has been achieved through many factors, including development of increasingly more sensitive Hepatitis B antigen (HBsAg) assays; the adoption in some countries of hepatitis B core antibody (anti-HBc) screening; an improved donor selection procedure; HBV vaccination programs; and finally the introduction of HBV nucleic acid testing (NAT). Because there is a tendency in transfusion medicine to add one safety measure on top of another to approach the ultimate goal of zero risks, costs become increasingly a matter of debate. It is obvious that any new measure in addition to existing methods or measures will have very poor cost effectiveness. Therefore each country needs to perform its own calculation based on the country’s own epidemiology, resources, political and public awareness of the risks, in order to choose the correct and most cost-efficient measures. Ideally, each country would make decisions regarding implementation of additional blood safety measures in the context of both the perceived benefit and the allocation of overall health care resources.
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Kupek E, Petry A. Comparison of epidemiological methods for estimation of hepatitis B incidence and residual risk for blood donors in southern Brazil. JOURNAL OF TRANSFUSION 2011; 2011:985383. [PMID: 25346858 PMCID: PMC4157395 DOI: 10.4061/2011/985383] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Revised: 03/09/2011] [Accepted: 03/23/2011] [Indexed: 11/24/2022]
Abstract
Background and Objective. The objective of this work was to compare three methods for estimating hepatitis B virus (HBV) incidence and residual risk. Methods. Computerized blood donor records in southern Brazil were examined for the period 2004–2006. The methods for estimating HBV incidence included stand-alone HBsAg, HBsAg yield method, and an extension of the latter which added recent anti-HBc seroconversions as incident HBV cases. Results. HBV incidences for the above methods were 9.91, 20.09, and 22.93 per 100000 repeat donors, respectively. In the same order, corresponding residual risks were 1 : 62482, 1 : 30821, and 1 : 47559, respectively. First-time donors had 52 higher HBV incidence compared to repeat donors. Conclusion. Although the three methods compared produced overlapping 95% confidence intervals, their variation was considerably lower for the method which included recent anti-HBc seroconversions. First-time donors are primary cause for concern regarding HBV transmission via blood transfusion in southern Brazil.
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Affiliation(s)
- Emil Kupek
- Departamento de Saúde Pública/CCS, Universidade Federal de Santa Catarina, 88040-900 Florianopolis, SC, Brazil
| | - Andrea Petry
- Hematology and Hemotherapy Center of Santa Catarina (HEMOSC), Florianopolis, SC, Brazil
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Zou S, Stramer SL, Notari EP, Kuhns MC, Krysztof D, Musavi F, Fang CT, Dodd RY. Current incidence and residual risk of hepatitis B infection among blood donors in the United States. Transfusion 2011; 49:1609-20. [PMID: 19413732 DOI: 10.1111/j.1537-2995.2009.02195.x] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
BACKGROUND This study used two approaches to estimate the current incidence of hepatitis B virus (HBV) in a US donor population. METHODS HBV incidence was estimated through the hepatitis B surface antigen (HBsAg) yield approach and the seroconversion method. Residual risk was estimated by the incidence–window period model. HBsAg yield refers to an HBsAg confirmed-positive, antibody against hepatitis B core antigen (anti-HBc)–nonreactive donation, adjusted for false-positive neutralization results. The number of HBsAg-seroconverting repeat donors divided by total number of person-years of evaluation or the HBsAg yield rate divided by HBsAg yield window gave rise to incidence estimates. RESULTS The seroconversion and the yield approach, respectively, gave an incidence estimate of 3.41 or 3.43 per 105 person-years. Using a revised infectious window period of 38 or 30 days for current HBsAg assays, the current residual risk for HBV was respectively estimated for 2006 to 2008 at 1 in 282,000 or 1 in 357,000 donations from the seroconversion approach and 1 in 280,000 or 1 in 355,000 donations from the yield approach. With the same database and methods, this is a decrease from 1 in 86,000 to 1 in 110,000 observed in 1997 to 1999. CONCLUSIONS Current HBV incidence and residual risk are lower than earlier estimates, especially in the youngest donors, but remain higher in the absence of HBV nucleic acid test than those for human immunodeficiency virus or hepatitis C virus (HCV). In addition to the exclusion of HBsAg false-positive donors, the reduction could reflect shortened window periods and decreased incidence rates due to vaccination or other reasons.
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Affiliation(s)
- Shimian Zou
- Transmissible Diseases Department, American Red Cross Blood Services, 15601 Crabbs BranchWay, Rockville MD 20855, USA.
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Brant LJ, Reynolds C, Byrne L, Davison KL. Hepatitis B and residual risk of infection in English and Welsh blood donors, 1996 through 2008. Transfusion 2011; 51:1493-502. [PMID: 21470235 DOI: 10.1111/j.1537-2995.2011.03108.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Globally, of all infections that donations are tested for, hepatitis B has the highest residual risk of transfusion transmission, despite donor selection criteria and advances in testing. Every blood donation in England and Wales is tested for hepatitis B surface antigen. Knowledge of infections being detected can inform donor selection and testing strategies. STUDY DESIGN AND METHODS Data on donation testing and infections detected are collated by the NHS Blood and Transplant and Health Protection Agency Epidemiology Unit. Infected donors are classified as having acute or chronic hepatitis B virus (HBV) by a clinician; their demographic characteristics were described. The prevalence (by acute or chronic HBV status, ethnicity, and geography) and incidence of infection were calculated between 1996 and 2008. The residual risk was calculated for four periods using a modification of the incidence and window period model; the effects of modifying variables were investigated. RESULTS Most infections (1047/1155) detected were chronic and seen in new donors. People with acute infections were more likely to be white and/or born in Western Europe. Prevalence was highest in donors from minority ethnic communities and in London. Incidence in repeat donors has halved in recent years. The estimated frequency of an infectious donation being missed was 1.37 per million donations (2006-2008), the lowest since surveillance began or three per year. CONCLUSION Many HBV infections in England and Wales were detected among new donors, who had chronic infection and were born overseas. The residual risk of infection declined over the 13 study years, but is still higher for HBV than other viral infections for which testing is undertaken.
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Affiliation(s)
- Lisa J Brant
- Health Protection Agency Centre for Infections and NHS Blood and Transplant, London, UK
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Abstract
Hepatitis B virus (HBV) remains a major risk of transfusion-transmitted infection due to the pre-seroconversion window period (WP), infection with immunovariant viruses, and with occult carriage of HBV infection (OBI). Reduction of HBV residual risk depends upon developing more sensitive HBV surface antigen (HBsAg) tests, adopting anti-HBc screening when appropriate, and implementing HBV nucleic acid testing (NAT), either in minipools or more efficiently in individual samples. HBV NAT combines the ability to significantly reduce the window period and to detect occult HBV carriage substantiating decades of clinical observation that HBsAg-negative/anti-HBc-positive blood could transmit HBV. Clinical observations suggest limited transmission rate of occult HBV compared to WP. Low transmission rate might be related to low viral load observed in OBIs or to the presence of mutants associated with occult carriage. OBIs carrying detectable anti-HBs ( approximately 50%) are essentially not infectious by transfusion. However, recent data suggest that the neutralizing capacity of low anti-HBs may be inefficient when overcome by exposure to high viral load. Anti-HBc blood units without detectable anti-HBs appear moderately infectious except in immunocompromised recipients. Immunodeficient elderly and patients receiving immunosuppressive treatments may be susceptible to infection with lower infectious dose even in the presence of anti-HBs. The immune status of blood recipients should be taken into consideration when investigating "post-transfusion" HBV infection. Pre-transfusion testing and post-transfusion long-term follow-up of recipients, and molecular analysis of the virus infecting both donor and recipient are critical to definitively incriminate transfusion in the transmission of HBV.
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Affiliation(s)
- Daniel Candotti
- National Health Service Blood & Transplant, Cambridge Blood Centre, Long Road, Cambridge CB2 2PT, UK.
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In Reply. Transfusion 2009. [DOI: 10.1111/j.1537-2995.2009.02147.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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