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Susan Stramer

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Papers by Susan Stramer

Prevalence, incidence, and risk factors of human immunodeficiency virus infection in blood donors in the Southeastern United States

Transfusion, Nov 2, 2016

BACKGROUND: Human immunodeficiency virus (HIV)-positive blood donors pose a risk to blood safety.... more BACKGROUND: Human immunodeficiency virus (HIV)-positive blood donors pose a risk to blood safety. The Southeastern United States has the highest reported HIV infection rates. Here we calculate HIV prevalence, incidence, and residual risk in Southeastern US blood donors and report risk factors disclosed by incident donors in counseling sessions.

Advancing risk assessment for emerging infectious diseases for blood and blood products: proceedings of a public workshop

Transfusion, Jul 31, 2012

Epidemiology Study (REDS). Detection of West Nile virus RNA and antibody in frozen plasma compone... more

Tick-Borne Encephalitis Virus Vaccine-Induced Human Antibodies Mediate Negligible Enhancement of Zika Virus Infection <i>In</i> <i>Vitro</i> and in a Mouse Model

mSphere, Feb 28, 2018

Recent reports in the scientific literature have suggested that antidengue virus (DENV) and anti-... more Recent reports in the scientific literature have suggested that antidengue virus (DENV) and anti-West Nile virus (WNV) immunity exacerbates Zika virus (ZIKV) pathogenesis in vitro and in vivo in mouse models. Large populations of immune individuals exist for a related flavivirus (tick-borne encephalitis virus [TBEV]), due to large-scale vaccination campaigns and endemic circulation throughout most of northern Europe and the southern Russian Federation. As a result, the question of whether anti-TBEV immunity can affect Zika virus pathogenesis is a pertinent one. For this study, we obtained 50 serum samples from individuals vaccinated with the TBEV vaccine FSME-IMMUN (Central European/Neudörfl strain) and evaluated their enhancement capacity in vitro using K562 human myeloid cells expressing CD32 and in vivo using a mouse model of ZIKV pathogenesis. Among the 50 TBEV vaccinee samples evaluated, 29 had detectable reactivity against ZIKV envelope (E) protein by enzyme-linked immunosorbent assay (ELISA), and 36 showed enhancement of ZIKV infection in vitro. A pool of the most highly reacting and enhanced samples resulted in no significant change in the morbidity/mortality of ZIKV disease in immunocompromised Stat2 Ϫ/Ϫ mice. Our results suggest that humoral immunity against TBEV is unlikely to enhance Zika virus pathogenesis in humans. No clinical reports indicating that TBEV vaccinees experiencing enhanced ZIKV disease have been published so far, and though the epidemiological data are sparse, our findings suggest that there is little reason for concern. This study also displays a clear relationship between the phylogenetic distance between two flaviviruses and their capacity for pathogenic enhancement.

Trypanosoma cruzi infection in North America and Spain: evidence in support of transfusion transmission (CME)

Transfusion, Feb 10, 2012

BACKGROUND: The United States, Canada, and Spain perform selective testing of blood donors for Tr... more BACKGROUND: The United States, Canada, and Spain perform selective testing of blood donors for Trypanosoma cruzi infection (Chagas disease) to prevent transfusion transmission. The donor, product, and patient characteristics associated with transfusiontransmitted infections are reviewed and the infectivity of components from donors with serologic evidence of infection is estimated. STUDY DESIGN AND METHODS: A systematic review of transfusion-transmitted T. cruzi cases and recipient tracing undertaken in North America and Spain is described. Cases were assessed for the imputability of the evidence for transfusion transmission. RESULTS: T. cruzi infection in 20 transfusion recipients was linked to 18 serologically confirmed donors between 1987 and 2011, including 11 identified only by recipient tracing. Cases were geographically widely distributed and were not associated with incident or autochthonous infections. Index clinical cases were described only in immunocompromised patients. All definite transmissions (n = 11) implicated apheresis or whole blood-derived platelets (PLTs), including leukoreduced and irradiated products. There is no evidence of transmission by red blood cells (RBCs) or frozen products, while transmission by whole blood transfusion remains a possibility. Recipient tracing reveals low component infectivity from serologically confirmed, infected donors of 1.7% (95% confidence interval [CI], 0.7%-3.5%) overall: 13.3% (95% CI, 5.6%-25.7%) for PLTs, 0.0% (95% CI, 0.0%-1.5%) for RBCs, and 0.0% (95% CI, 0%-3.7%) for plasma and cryoprecipitate. CONCLUSIONS: T. cruzi is transmitted by PLT components from some donors with serologic evidence of infection. Evidence of transmission before the implementation of widespread testing in the countries studied is sparse, and selective testing of only PLT and fresh whole blood donations should be considered.

Dengue Virus Immunity Increases Zika Virus-Induced Damage during Pregnancy

Immunity, Mar 1, 2019

Highlights d Dengue-specific antibodies can enhance Zika virus pathogenesis during pregnancy d En... more

Emerging Infectious Diseases That Threaten the Blood Supply

Seminars in Hematology, 2007

Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on ... more Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on the novel coronavirus COVID-19. The COVID-19 resource centre is hosted on Elsevier Connect, the company's public news and information website. Elsevier hereby grants permission to make all its COVID-19-related research that is available on the COVID-19 resource centre-including this research content-immediately available in PubMed Central and other publicly funded repositories, such as the WHO COVID database with rights for unrestricted research re-use and analyses in any form or by any means with acknowledgement of the original source. These permissions are granted for free by Elsevier for as long as the COVID-19 resource centre remains active.

Prevalence, incidence, and residual risk of human immunodeficiency virus and hepatitis C virus infections among United States blood donors since the introduction of nucleic acid testing

Transfusion, Mar 12, 2010

Prevalence, incidence, and residual risk of human immunodeficiency virus and hepatitis C virus in... more

Enhancement of Zika virus pathogenesis by preexisting antiflavivirus immunity

Science, Apr 14, 2017

Zika virus (ZIKV) is spreading rapidly into regions around the world where other flaviviruses, su... more Zika virus (ZIKV) is spreading rapidly into regions around the world where other flaviviruses, such as dengue virus (DENV) and West Nile virus (WNV), are endemic. Antibody-dependent enhancement has been implicated in more severe forms of flavivirus disease, but whether this also applies to ZIKV infection is unclear. Using convalescent plasma from DENV-and WNV-infected individuals, we found substantial enhancement of ZIKV infection in vitro that was mediated through immunoglobulin G engagement of Fcγ receptors. Administration of DENV-or WNVconvalescent plasma into ZIKV-susceptible mice resulted in increased morbidity-including fever, viremia, and viral loads in spinal cord and testes-and increased mortality. Antibody-dependent enhancement may explain the severe disease manifestations associated with recent ZIKV outbreaks and highlights the need to exert great caution when designing flavivirus vaccines. Zika virus (ZIKV) is a mosquito-transmitted flavivirus endemic to parts of Africa and Asia. After its discovery in 1947, the virus remained relatively obscure until 2015, when a large outbreak occurred in Brazil and rapidly spread outward to other countries in South and Central America (1). Today, ZIKV is endemic to several U.S. territories, mainly Puerto Rico, and active ZIKV transmission has been reported in Florida and Texas as

Risk factors for retrovirus and hepatitis virus infections in accepted blood donors

Transfusion, Dec 4, 2014

Background-Risk factor surveillance among infected blood donors provides information on the effec... more Background-Risk factor surveillance among infected blood donors provides information on the effectiveness of eligibility assessment and is critical for reducing risk of transfusiontransmitted infection (TTI). Methods-American Red Cross, Blood Systems, New York Blood Center, and OneBlood participated in a case-control study from 2010-2013. Donors with serologic and nucleic acid testing (NAT) or NAT-only confirmed HIV, HBV, HCV, or serology confirmed HTLV infections (cases), and donors with false-positive results (controls) were interviewed for putative behavioral and demographic risks. Frequencies and adjusted odds ratios (AOR) from multivariable logistic regression analyses for each exposure in cases compared to controls are reported. Results-In the study, 196 HIV, 292 HBV, 316 HCV, and 198 HTLV cases, and 1587 controls were interviewed. For HIV, sex with an HIV+ person [AOR=132, 95% Confidence Interval (CI) 27-650] and male-male sex [AOR=62, 95%CI 27-140] were primary risk factors. For HBV, firsttime status (FT) [AOR=16, 95% CI 10-27], sex with an injection drug user (IDU) [AOR=11, 95%CI 5-28], and Black race [AOR=11, 95%CI 6-19] were primary. For HCV, IDU [AOR=42, 95%CI 13-136], FT [AOR=18, 95%CI 10-30], and a family member with hepatitis [AOR=15,

Screening for<i>Babesia microti</i>in the U.S. Blood Supply

The New England Journal of Medicine, Dec 8, 2016

BACKGROUND Babesia microti, a tickborne intraerythrocytic parasite that can be transmitted by mea... more BACKGROUND Babesia microti, a tickborne intraerythrocytic parasite that can be transmitted by means of blood transfusion, is responsible for the majority of cases of transfusiontransmitted babesiosis in the United States. However, no licensed test exists for screening for B. microti in donated blood. We assessed data from a large-scale, investigational product-release screening and donor follow-up program. METHODS From June 2012 through September 2014, we performed arrayed fluorescence immunoassays (AFIAs) for B. microti antibodies and real-time polymerase-chain-reaction (PCR) assays for B. microti DNA on blood-donation samples obtained in Connecticut, Massachusetts, Minnesota, and Wisconsin. We determined parasite loads with the use of quantitative PCR testing and assessed infectivity by means of the inoculation of hamsters and the subsequent examination for parasitemia. Donors with test-reactive samples were followed. Using data on cases of transfusiontransmitted babesiosis, we compared the proportions of screened versus unscreened donations that were infectious. RESULTS Of 89,153 blood-donation samples tested, 335 (0.38%) were confirmed to be positive, of which 67 (20%) were PCR-positive; 9 samples were antibody-negative (i.e., 1 antibody-negative sample per 9906 screened samples), representing 13% of all PCR-positive samples. PCR-positive samples were identified all through the year; antibody-negative infections occurred from June through September. Approximately one third of the red-cell samples from PCR-positive or high-titer AFIA-positive donations infected hamsters. Follow-up showed DNA clearance in 86% of the donors but antibody seroreversion in 8% after 1 year. In Connecticut and Massachusetts, no reported cases of transfusion-transmitted babesiosis were associated with screened donations (i.e., 0 cases per 75,331 screened donations), as compared with 14 cases per 253,031 unscreened donations (i.e., 1 case per 18,074 unscreened donations) (odds ratio, 8.6; 95% confidence interval, 0.51 to 144; P = 0.05). Overall, 29 cases of transfusion-transmitted babesiosis were linked to blood from infected donors, including blood obtained from 10 donors whose samples tested positive on the PCR assay 2 to 7 months after the implicated donation. CONCLUSIONS Blood-donation screening for antibodies to and DNA from B. microti was associated with a decrease in the risk of transfusion-transmitted babesiosis. (Funded by the American Red Cross and Imugen; ClinicalTrials.gov number, NCT01528449.

Emerging infectious disease agents and their potential threat to transfusion safety

Transfusion, Aug 1, 2009

BACKGROUND: Emerging infections have been identified as a continuing threat to human health. Many... more BACKGROUND: Emerging infections have been identified as a continuing threat to human health. Many such infections are known to be transmissible by blood transfusion, while others have properties indicating this potential. There has been no comprehensive review of such infectious agents and their threat to transfusion recipient safety to date. STUDY DESIGN AND METHODS: The members of AABB's Transfusion Transmitted Diseases Committee reviewed a large number of information sources in order to identify infectious agents with actual or potential risk of transfusion transmission now or in the future in the US or Canada; with few exceptions, these agents do not have available interventions to reduce the risk of such transmission. Using a group discussion and writing process, key characteristics of each agent were identified, researched, recorded and documented in standardized format. A group process was used to prioritize each agent on the basis of scientific/ epidemiologic data and a subjective assessment of public perception and/or concern expressed by regulatory agencies. RESULTS: Sixty-eight infectious agents were identified and are described in detail in a single Supplement to TRANSFUSION. Key information will also be provided in web-based form and updated as necessary. The highest priorities were assigned to Babesia species, Dengue virus, and vCJD. CONCLUSION: The information is expected to support the needs of clinicians and transfusion medicine experts in the recognition and management of emerging infections among blood donors and blood recipients.

Use of a rapid electronic survey methodology to estimate blood donors' potential exposure to emerging infectious diseases: Application of a statistically representative sampling methodology to assess risk in US blood centers

Transfusion, Aug 3, 2020

Funding information U.S. Food and Drug Administration: Medical Countermeasures Initiative (MCMi) ... more Funding information U.S. Food and Drug Administration: Medical Countermeasures Initiative (MCMi) a test survey was developed and deployed to a statistically representative sample frame of blood donors from five blood collecting organizations. Donors were directed to an online survey to ascertain their recent travel and potential exposure to Middle East respiratory syndrome coronavirus (MERS-CoV). Results: A total of 7128 responses were received from 54 256 invitations. The age-adjusted estimated total number of blood donors potentially exposed to MERS-CoV was approximately 15 640 blood donors compared to a lower U.S. general population-based estimate of 9610 blood donors. Conclusion: The structured donor demographic sample-based data provided an assessment of blood donorsʼ potential exposure to an emerging pathogen that was 63% larger than the U.S. population-based estimate. This illustrates

Characteristics of transfusion‐transmitted <i>Babesia microti</i> , American Red Cross 2010‐2017

Transfusion, Jun 27, 2019

BACKGROUNDBabesia microti, a red blood cell (RBC) parasite transmitted naturally to vertebrate ho... more BACKGROUNDBabesia microti, a red blood cell (RBC) parasite transmitted naturally to vertebrate hosts by ixodid ticks, is endemic to the northeastern and upper midwestern United States, with the geographic range of infected ticks expanding. B. microti is a blood safety issue with &gt;200 transfusion‐transmissions reported.METHODSThe American Red Cross's Hemovigilance program investigated hospital‐reported transfusion‐transmitted babesiosis (TTB) cases. Follow‐up samples from involved donors were tested for B. microti antibodies and parasite DNA, the latter by real‐time polymerase chain reaction (PCR). Test‐positive donors were permanently deferred from future donations.RESULTSB. microti‐positive donors were implicated in 77 of 143 suspect TTB cases investigated from 2010 through 2017. In four cases, two positive donors were identified for a total of 81 positive donors. In three cases, a RBC unit was split and components transfused multiple times to the same pediatric recipient. RBCs were the transmitting product in all cases. At follow‐up, all involved donors were antibody positive; 25 donors were also PCR positive. Positive donations were collected throughout the year, peaking in the summer. Most donors (78) were resident of, or traveled to (2), an endemic state. One donor resided in a non‐endemic state without relevant travel history. One fatality listed babesia as a contributing factor. No implicated donation was screened by an investigational protocol.CONCLUSIONSBabesiosis remains a blood safety issue. Prior to FDA‐licensed screening test availability and final FDA Guidance, blood collectors in endemic states investigationally tested none, a portion, or all collections. Future expanded testing will reduce the frequency of TTB cases.

Viral marker rates among blood donors before and after the terrorist attacks on the United States on September 11, 2001

Transfusion, Sep 1, 2002

The terrorist attacks on the United States on September 11, 2001, were met by an unprecedented pu... more The terrorist attacks on the United States on September 11, 2001, were met by an unprecedented public response. One part of this response was an almost overwhelming increase in blood donations. 1-3 It is to be hoped that many of those who donated in response to the human tragedy will become regular donors. However, the media have expressed concern that these new donors received unexpected bad news inasmuch as some were found to be positive in routine testing for transfusion-transmissible infections. 4 In the past, Busch and colleagues 5 clearly showed that the rates of positive infectious disease marker tests among new donors responding to a natural disaster were no different from those found among firsttime donors presenting at other times. We therefore sought to assess the infectious disease status of those donors who gave blood immediately before (between August 22 and September 10) or after September 11, 2001 (between September 11 and September 30). We have assembled a database of infectious disease test results representing all donations to the American Red Cross. We used this database to analyze the prevalence of key infectious disease markers among first-time and repeat donors of allogeneic whole blood who gave during the 20 days before September 11, 2001, and the 20 days starting on that date. All donations were tested using the following screening tests: HBsAg (ELISA System 2.0 Procedure B, Ortho Clinical Diagnostics, Raritan, NJ), anti-HCV (ELISA System 3.0, Ortho Clinical Diagnostics), and anti-HIV-1/HIV-2 (rDNA EIA, Abbott Laboratories, Abbott Park, IL). Confirmatory and/or supplemental testing was performed on all repeatedly reactive samples using the following algorithms. Samples repeatedly reactive for HBsAg were tested by a second HBsAg EIA (Procedure C, Auszyme Monoclonal, Abbott) and, if repeatedly reactive, were tested by a neutralization assay (HBsAg Confirmatory Assay, Abbott). Samples repeatedly reactive for anti-HCV were further tested by a RIBA (HCV RIBA 3.0, Chiron, Corp., Emeryville, CA). Anti-HIV-1/HIV-2 repeatedly reactive samples were confirmed by HIV-1 Western blot (Calypte, Rockville, MD); HIV-2 confirmatory testing was also performed by EIA and Western blot (Bio-Rad, Redmond, WA). In some instances, additional confirmatory information was derived by consideration of

A probable case of West Nile virus transfusion transmission

Transfusion, Feb 5, 2017

BACKGROUND: Transfusion-transmitted West Nile virus (WNV) infection is infrequent as a result of ... more BACKGROUND: Transfusion-transmitted West Nile virus (WNV) infection is infrequent as a result of minipool (MP) and individual-donation (ID) nucleic acid testing (NAT) of blood donations. ID-NAT is triggered on the basis of local WNV activity identified by MP-NAT. STUDY DESIGN AND METHODS: A 78-year-old male patient who was treated for cardiac disease received 14 blood components from 30 donors in August 2016. He was discharged 7 days after aortic valve replacement and coronary bypass surgery, but was readmitted on Day 12 with symptoms of viral infection, and eventually was diagnosed with aseptic meningitis. The patent died on Day 51. ABBREVIATIONS: ARC 5 American Red Cross; ID-NAT 5 individual-donation nucleic acid testing; MP-NAT 5 minipool nucleic acid testing; TT-WNV 5 transfusiontransmitted West Nile virus.

Prevalence of <scp>human immunodeficiency virus</scp> , <scp>hepatitis B virus,</scp> and <scp>hepatitis C virus</scp> in United States blood donations, 2015 to 2019: The <scp>Transfusion‐Transmissible</scp> Infections Monitoring System ( <scp>TTIMS</scp> )

Transfusion, Aug 31, 2020

BackgroundThe Transfusion‐Transmissible Infections Monitoring System (TTIMS) combines data from f... more BackgroundThe Transfusion‐Transmissible Infections Monitoring System (TTIMS) combines data from four US blood collection organizations including approximately 60% of all donations to monitor demographic and temporal trends in infectious disease markers and policy impacts.Study Design and MethodsHuman immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) consensus‐positive definitions combined serology and nucleic acid testing results. These along with donor and donation characteristics were assembled into a single data set. Overall donation prevalence and demographic subsets were compared pre‐ and post‐implementation of the 2015 change in men who have sex with men (MSM) deferral policy, among other prevalence comparisons.ResultsFrom October 2015 to September 2019, there were 712 HIV‐, 1735 HBV‐, and 5217 HCV‐positive samples identified from approximately 27.5 million donations (&gt;9.4 million donors). Prevalences per 100 000 donations were 2.6 (HIV), 6.3 (HBV), and 19.0 (HCV), and the highest for all three agents were in donations from first‐time male donors. Two slight but significant increases in HIV prevalence were observed, both for comparisons of Year 1 (pre‐MSM policy change) versus Year 4 (post‐MSM policy change) for first‐time males and first‐time females; in contrast, similar comparisons demonstrated decreases in HCV prevalence (all donors and general trends for males and females). Except for HIV, prevalence increased with age; for all agents, prevalence was markedly higher in the south.ConclusionsNo major trends were observed over 4 years covering the MSM policy change from indefinite to a 12‐month deferral, but ongoing monitoring is warranted. Demographic trends are consistent with those observed in other donor studies and community trends.

Xenotropic murine leukemia virus-related virus does not pose a risk to blood recipient safety

Transfusion, Nov 21, 2011

ABSTRACT When xenotropic murine leukemia virus-related virus (XMRV) was first reported in associa... more ABSTRACT When xenotropic murine leukemia virus-related virus (XMRV) was first reported in association with chronic fatigue syndrome, it was suggested that it might offer a risk to blood safety. Thus, the prevalence of the virus among blood donors and, if present, its transmissibility by transfusion need to be defined. Two populations of routine blood donor samples (1435 and 13,399) were obtained for prevalence evaluations; samples from a linked donor-recipient repository were also evaluated. Samples were tested for the presence of antibodies to XMRV-related recombinant antigens and/or for XMRV RNA, using validated, high-throughput systems. The presence of antibodies to XMRV could not be confirmed among a total of 17,249 blood donors or recipients (0%; 95% confidence interval [CI], 0%-0.017%); 1763 tested samples were nonreactive for XMRV RNA (0%; 95% CI, 0%-0.17%). Evidence of infection was absent from 109 recipients and 830 evaluable blood samples tested after transfusion of a total of 3741 blood components. XMRV and related murine leukemia virus (MLV) markers are not present among a large population of blood donors and evidence of transfusion transmission could not be detected. Thus, these viruses do not currently pose a threat to blood recipient safety and further actions relating to XMRV and MLV are not justified.

Development of a multisystem surveillance database for transfusion-transmitted infections among blood donors in the United States

Transfusion, Aug 25, 2016

BACKGROUND: The frequency of positive test results for transfusion-transmitted infections (TTIs) ... more BACKGROUND: The frequency of positive test results for transfusion-transmitted infections (TTIs) among blood donors is an important index of safety; thus, appropriate monitoring is critical, particularly when there are changes in policies affecting donor suitability. STUDY DESIGN AND METHODS: Testing algorithms from three large blood systems were reviewed and consensus definitions for a surveillance-positive result for hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), and human T-cell lymphotropic virus (HTLV) established. In addition, information on each donation, including donor demographics and location, was collected. Combined data were analyzed to characterize the epidemiology of TTIs by person, place, and time. RESULTS: Data from 14.8 million donations were collected for 2011 to 2012, representing more than 50% of the US blood supply. Surveillance-positive rates per 10,000 donations were as follows: HBV, 0.76; HCV, 2.0; HIV, 0.28; and HTLV 0.34. Rates did not vary between the 2 years, although there was variation within a year. With the exception of HTLV, rates were higher among males, and all rates were higher among first-time donations. Windowperiod donations (those positive only in nucleic acid tests) were infrequent (HBV, 13; HCV, 60; HIV, 14) during the 2year period. Frequencies of surveillance-positive results varied by donor age and residence location. CONCLUSIONS: We demonstrated that standardized data from multiple major US blood systems can be combined and analyzed for change. However, TTI frequencies are low, impacting their sensitivity to change. Furthermore, observed fluctuations in TTI frequencies may be secondary to changes in blood donor demographics rather than necessarily reflecting the immediate impact of policy modification. I n the United States, blood is collected by a number of different independent blood centers and integrated blood systems, operating on a not-for-profit basis. The collection, testing, and processing of blood is highly regulated through the US Food and Drug Administration (FDA), through state health departments, and through voluntary accreditation. Thus, procedures are highly standardized. However, there is no mechanism for routine, central reporting of blood system data. In common with a number ABBREVIATIONS: ARC 5 American Red Cross; BSI 5 Blood Systems, Inc.; DHHS 5 Department of Health and Human Services; MSM 5 men who have had sex with other men; NYBC 5 New York Blood Center; TTI(s) 5 transfusiontransmitted infection(s); TTIMS 5 Transfusion-Transmissible Infection Monitoring Systems.

Comparison of seven hepatitis B virus (HBV) nucleic acid testing assays in selected samples with discrepant HBV marker results from United States blood donors

Transfusion, Apr 17, 2014

BackgroundSensitive triplex nucleic acid tests (NATs) are implemented for blood donation screenin... more BackgroundSensitive triplex nucleic acid tests (NATs) are implemented for blood donation screening worldwide. Assays have variable ability to detect low‐level hepatitis B virus (HBV) DNA. At borderline DNA detection levels, where Poisson distribution impacts results, distinguishing true‐positive from false‐positive results is challenging. Algorithms are needed to confirm such low‐level HBV DNA–positive samples.Study Design and MethodsA total of 135 blood donor samples reactive by one or more HBV markers that provided discrepant results were tested undiluted with four commercial NATs: Ultrio, Ultrio Plus, MPX, and a quantitative assay (SuperQuant). To further explore discrepancies, three additional in‐house NATs including real‐time polymerase chain reaction (PCR) and nested PCR and sequencing were performed.ResultsThe numbers reactive of these 135 “difficult” samples by four commercial NATs were as follows: 39 of 107 (36%) with SuperQuant, 40 (30%) with Ultrio, 100 (74%) with Ultrio Plus, and 102 (76%) with MPX. Of the seven NATs, 109 (81%) samples were reactive by at least two assays and thus considered confirmed positive of which 67 (50%) generated a sequence. Ultrio Plus and MPX performed similarly as above (80%‐85% detected of 109 and 81%‐90% of 67, respectively). Older (median, 49 years), HBV core antibody–reactive donors carried predominantly Genotype A (58%) with high‐frequency amino acid substitutions in the major hydrophilic region of the S‐protein. Younger (median, 24 years) hepatitis B surface antigen–positive donors carried wild‐type strains predominantly Genotype B (32%) and E (24%), the latter in an apparent cluster.ConclusionsHighly sensitive NATs require new confirmatory algorithms as presented optimally using different genomic regions or sequence generation. The introduction of immigration‐related HBV genotypes may impact HBV epidemiology in the United States.

Indeterminate results in blood donor testing: What you don't know can hurt you

Transfusion Medicine Reviews, Apr 1, 2000