Publications by authors named "Grebe E"

Background: Increasing syphilis infection rates are a concerning issue worldwide. Blood donation screening is an opportunity to monitor the burden of asymptomatic infections, providing information on contemporary factors associated with infection and public health insights into transmission.

Methods: Blood donations collected at five Brazilian blood centers between January 2020 and February 2022 were screened with treponemal or non-treponemal assays according to local protocols, followed by alternate Enzyme-Linked Immunosorbent Assay (ELISA); samples with reactive or indeterminate results in the alternate ELISA were further tested with the rapid plasma reagin (RPR), and categorized as RPR-positive or RPR-negative.

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Background: General vaccination rates have been falling globally despite unequivocal health benefits. Noncompliance can result from access barriers and/or hesitant attitudes. Few studies have investigated the prevalence and determinants of noncompliance with COVID-19 vaccination in blood donors.

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Article Synopsis
  • - COVID-19 convalescent plasma (CCP) may be beneficial for immunocompromised patients, but the FDA's current threshold for qualifying plasma based on antibody levels might be too low.
  • - A study evaluated antibody levels in blood donors with different infection and vaccination histories, revealing that those with hybrid immunity (infection followed by vaccination) had higher antibody levels and better neutralizing capabilities.
  • - The research suggests establishing new test-based criteria for qualifying CCP, highlighting that plasma with high antibody levels could effectively neutralize various COVID-19 variants for several months after infection or vaccination.
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Background: Exposure to antiretrovirals at or early after HIV acquisition can suppress viral replication and blunt antibody (Ab) responses; a reduced HIV detectability could impact diagnosis and blood donation screening.

Methods: We used three antigen (Ag)/Ab assays and one nucleic acid test (NAT) to analyze samples collected in pre-exposure prophylaxis (PrEP) trials (iPrEx; Partners PrEP) before infection detection by Ab-only rapid diagnostic tests (RDTs), and in early antiretroviral treatment (ART) initiation studies (RV254; SIPP).

Results: Reactivity using NAT and Ag/Ab assays in samples collected up to 8 weeks prior to the first reactive RDT from 251 PrEP trials participants varied between 49-61% for active PrEP users and between 27-37% for placebo users.

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In response to the 2015 Zika virus (ZIKV) epidemic that occurred in Brazil, numerous commercial serological assays have been developed for clinical and research applications. Diagnosis of recent infection in pregnant women remains challenging. Having standardized, comparative studies of ZIKV tests is important for implementing optimal diagnostic testing and disease surveillance.

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Background: Monitoring genotypes of HIV infections in blood donors may provide insights into infection trends in the general population.

Methods: HIV RNA was extracted from plasma samples of blood donors confirmed as HIV positive by blood screening nucleic acid and antibody tests. HIV genome target regions were amplified using nested real time-polymerase chain reaction followed by next-generation sequencing.

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Article Synopsis
  • Long COVID is a complex condition affecting about 12% of COVID-19 survivors, with various symptoms and no widely accepted definition, pushing researchers to study its immune profile.
  • A survey of over 33,000 blood donors revealed that higher levels of anti-nucleocapsid antibodies are linked to an increased risk of long COVID, while higher anti-spike IgG levels can reduce that risk.
  • The study identified four clinical subphenotypes—ranging from neurological to multi-systemic symptoms—suggesting that different immune responses may contribute to varied long COVID experiences.
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Article Synopsis
  • * A study involving 142,599 blood donors established a new, lower threshold for detecting past infections using the Ortho VITROS Anti-SARS-CoV-2 Total-N Antibody assay, which boosted detection sensitivity while keeping specificity above 98%.
  • * The updated test showed a high sensitivity of 98.1% for unvaccinated individuals and 95.6% for those who were vaccinated, though sensitivity was influenced by factors like the virus variant, donor age,
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Article Synopsis
  • - The Asanté HIV-1 Rapid Recency assay identified HIV infection about 18 days later than traditional nucleic acid tests, indicating a delay in detection.
  • - It showed performance comparable to 19 other rapid HIV antibody tests already in use.
  • - If approved by regulators, this assay could be integrated into national HIV testing systems, allowing for the collection of HIV recency information during regular screenings without needing extra tests.
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Background And Objectives: Accurate HIV incidence estimates among blood donors are necessary to assess the effectiveness of programs aimed at limiting transfusion-transmitted HIV. We assessed the impact of undisclosed HIV status and antiretroviral (ARV) use on HIV recency and incidence estimates using increasingly comprehensive recent infection testing algorithms.

Materials And Methods: Using 2017 donation data from first-time and lapsed donors, we populated four HIV recency algorithms: (1) serology and limiting-antigen avidity testing, (2) with individual donation nucleic amplification testing (ID-NAT) added to Algorithm 1, (3) with viral load added to Algorithm 2 and (4) with ARV testing added to Algorithm 3.

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Introduction: Cardiometabolic diseases are associated with greater COVID-19 severity; however, the influences of cardiometabolic health on SARS-CoV-2 infections after vaccination remain unclear. Our objective was to investigate the associations between temporal blood pressure and total cholesterol patterns and incident SARS-CoV-2 infections among those with serologic evidence of vaccination.

Methods: In this prospective cohort of blood donors, blood samples were collected in 2020-2021 and assayed for binding antibodies of SARS-CoV-2 nucleocapsid protein antibody seropositivity.

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Background And Objectives: Confirmed COVID-19 diagnoses underestimate the total number of infections. Blood donors can provide representative seroprevalence estimates, which can be leveraged into reasonable estimates of total infection counts and infection fatality rate (IFR).

Materials And Methods: Blood donors who donated after each of three epidemic waves (Beta, Delta and first Omicron waves) were tested for anti-SARS-CoV-2 nucleocapsid antibodies using the Roche Elecsys anti-SARS-CoV-2 total immunoglobulin assay.

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Objectives: We estimated changes in the HIV incidence from 2013-2018 in Eshowe/Mbongolwane, KwaZulu-Natal, South Africa where Médecins Sans Frontières is engaged in providing HIV testing and care since 2011.

Methods: Using data from two cross-sectional household-based surveys conducted in 2013 and 2018, with consenting participants aged 15-59 years, we applied the incidence estimation frameworks of Mahiane et al and Kassanjee et al.

Results: In total, 5599 (62.

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Article Synopsis
  • The U.S. Nationwide Blood Donor Seroprevalence Study tracked SARS-CoV-2 antibody levels from July 2020 to December 2021, adapting testing methods as vaccine uptake increased and pandemic conditions changed.* -
  • The study assessed the effectiveness of the Ortho anti-nucleocapsid (NC) test as a substitute for the Roche NC test, finding high agreement in results and confirming that most specimens provided consistent reactivity.* -
  • Overall, the use of parallel testing on both Roche and Ortho platforms demonstrated high efficiency and agreement, making it valuable for large-scale seroprevalence studies that monitor the spread of COVID-19.*
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Early detection of Zika virus (ZIKV) transmission within geographic regions informs implementation of community mitigation measures such as vector reduction strategies, travel advisories, enhanced surveillance among pregnant women, and possible implementation of blood and organ donor screening or deferral. Standardized, comparative assessments of ZIKV assay and testing lab performance are important to develop optimal approaches to ZIKV diagnostic testing and surveillance. We conducted an expanded blinded panel study to characterize and compare the analytical performance of fifteen diagnostic and blood screening ZIKV NAT assays, including detection among single- and multiplex assays detecting ZIKV, dengue virus (DENV) and chikungunya virus (CHIKV).

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Standard-of-care HIV pre-exposure prophylaxis (PrEP) is highly efficacious, but uptake of and persistence on a daily oral pill is low in many settings. Evaluation of alternate PrEP products will require innovation to avoid the unpractically large sample sizes in noninferiority trials. We propose estimating HIV incidence in people not on PrEP as an external counterfactual to which on-PrEP incidence in trial subjects can be compared.

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Given the possibility for disease transmission, this study was performed to determine whether there is detectable SARS-CoV-2 viral RNA in the blood of deceased tissue donors. A retrospective analysis of blood samples from eligible deceased tissue donors from Oct 2019 through June 2020 was performed. Plasma aliquots were initially tested with a SARS-CoV-2 NAT Assay; positive samples were further tested using an alternate NAT and an antibody assay.

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Blood donations in South Africa are tested for HIV RNA using individual donation NAT (ID-NAT), allowing detection and rapid antiretroviral therapy (ART) of acute HIV infections. We enrolled a cohort of acute and recent HIV-infected blood donation candidates in South Africa in 2015-2018, measured HIV antibody, ID-NAT, and recency of infection <195 days (Sedia LAg) at enrollment and initiated early ART. A small cohort of HIV elite controllers was followed without treatment.

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Background: To inform public health policy, it is critical to monitor coronavirus disease 2019 vaccine effectiveness (VE), including against acquiring infection.

Methods: We estimated VE using self-reported vaccination in a retrospective cohort of repeat blood donors who donated during the first half of 2021, and we demonstrated a viable approach for monitoring VE via serological surveillance.

Results: Using Poisson regression, we estimated an overall VE of 88.

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Background: Testing for 'recent HIV infection' is common in surveillance, where only population-level estimates (of incidence) are reported. Typically, 'recent infection' is a category, obtained by applying a threshold on an underlying continuous biomarker from some laboratory assay(s). Interpreting the biomarker values obtained for individual subjects, as estimates of the date of infection, has obvious potential applications in the context of studies of early infection, and has also for some years attracted significant interest as an extra component of post-test counselling and treatment initiation.

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Introduction: Rapid initiation of antiretroviral therapy (ART) in early HIV infection is important to limit seeding of the viral reservoir. A number of studies have shown that if ART is commenced prior to seroconversion, the seroconversion may, or may not, occur. We aimed to assess whether seroreversion or no seroconversion occurs using samples collected during an early treatment study in South Africa.

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Background: Except for public health case reports, the incidence of Zika virus (ZIKV), chikungunya virus (CHIKV), and dengue virus (DENV) infection are not available to assess the potential blood transfusion safety threat in Brazil.

Methods: Pools of 6 donation samples (MP6) left over from human immunodeficiency virus, hepatitis B virus, and hepatitis C virus nucleic acid testing were combined to create MP18 pools (3 MP6 pools). Samples were tested using the Grifols triplex ZIKV, CHIKV, and DENV real-time transcription mediated amplification assay to estimate prevalence of RNAemia and incidence, and to compare these results to case reports in São Paulo, Belo Horizonte, Recife, and Rio de Janeiro, from April 2016 through June 2019.

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