Correlation of improved hepatitis B surface antigen detection limits with hepatitis B virus DNA nucleic acid test yield in blood donations

Prevalence of Dengue, Chikungunya and Zika Viruses in Blood Donors in the State of Pará, Northern Brazil: 2018-2020

Arboviruses have been reported over the years as constant threats to blood transfusion recipients, given the high occurrence of asymptomatic cases and the fact that the presence of viremia precedes the onset of symptoms, making it possible that infected blood from donors act as a source of dissemination. This work aims to identify the prevalence of dengue virus (DENV), Zika virus (ZIKV) and Chikungunya virus (CHIKV) infection in blood donors during epidemic and non-epidemic periods; classify the donor as symptomatic or asymptomatic; and verify the need to include DENV, CHIKV and ZIKV in the nucleic acid test (NAT) platform in northern Brazil. We investigated 36,133 thousand donations in two years of collection in Northern Brazil. One donor was positive for DENV and one for CHIKV (0.002% prevalence). As the prevalence for arboviruses was low in this study, it would not justify the individual screening of samples from donors in a blood bank. Thus, DENV- and CHIKV-positive samples were simulated in different amounts of sample pools, and both were safely detected by molecular biology even in a pool of 14 samples, which would meet the need to include these three viruses in the routine of blood centers in endemic countries such as Brazil.

Performance characteristics of the high sensitivity Alinity i & ARCHITECT HBsAg Next Qualitative/Confirmatory assays

Despite improvement in vaccinations, Hepatitis B remains a major health concern due to the difficulty of prevention even in low endemic areas such as Europe. In this report we describe the performance characteristics of the new HBsAg Next Qualitative and HBsAg Next Confirmatory assays designed for blood screening and diagnostic purposes on the Alinity i and ARCHITECT fully automated systems. The new assays were evaluated in comparison to the ARCHITECT HBsAg Qualitative II and Confirmatory assays on seroconversion, analytical sensitivity, and mutant panels along with testing of over 400 clinical positive samples demonstrating excellent improvements in sensitivity. Additionally, specificity was shown to be improved with testing of over 6000 donors and 240 diagnostic specimens. Overall, the Alinity i & ARCHITECT HBsAg Next assays have taken a step forward in improving the detection of Hepatitis B virus.

Recent and occult hepatitis B virus infections among blood donors in the United States

BACKGROUND

Characteristics of US blood donors with recent (RBI) or occult (OBI) hepatitis B virus (HBV) infection are not well defined.

METHODS

Donors with RBI and OBI were identified by nucleic acid and serologic testing among 34.4 million donations during 2009-2015. Consenting donors were interviewed and their HBV S-gene sequenced.

RESULTS

The overall rate of HBV-infected donors was 7.95 per 100,000; of these, 0.35 per 100,000 and 1.70 per 100,000 were RBI and OBI, respectively. RBI (n = 120) and OBI (n = 583) donors constituted 26% of all HBV-infected (n = 2735) donors. Detection of HBV DNA in 92% of OBI donors required individual donation nucleic acid testing. Donors with OBI compared to RBI were older (mean age, 48 vs 39 years; p < 0.0001) with lower median viral loads (9 vs. 529 IU/mL; p < 0.0001). A higher proportion of OBI than RBI donors were born or resided in an endemic country (39% vs. 5%; p = 0.0078). Seventy-seven percent of all RBI and OBI donors had multiple sex partners, an HBV-risk factor. Of 40 RBI and 10 OBI donors whose S gene was sequenced, 33 (83%) and 6 (60%), respectively, carried HBV subgenotype A2; 18 (55%) and 2 (33%), respectively, shared an identical sequence. Infection with 1 or more putative HBV-immune-escape mutants was identified in 5 (50%) of OBI but no RBI donors.

CONCLUSION

RBI and OBI continue to be identified at low rates, confirming the importance of comprehensive HBV DNA screening of US blood donations. HBV-infected donors require referral for care and evaluation and contact tracing; their HBV strains may provide important information on emergent genotypes.

An ultra-sensitive Abbott ARCHITECT® assay for the detection of hepatitis B virus surface antigen (HBsAg)

BACKGROUND

Critical to the identification of HBV infection and the prevention of transfusion transmitted disease is the sensitive and accurate detection of Hepatitis B virus surface antigen (HBsAg). Improvements in HBsAg assay sensitivity approaching the performance of nucleic acid testing (NAT) are essential to further reduce the detection window for acute HBV infection in regions where NAT is not widely available.

OBJECTIVES AND STUDY DESIGN

An improved HBsAg assay on the fully-automated Abbott ARCHITECT^® platform was developed to improve sensitivity, mutant and genotype detection.

RESULTS

The analytical sensitivity of the improved prototype assay is 5.2 mIU/ml, which is 3.86- to 14.54-fold more sensitive than comparator assays based on the WHO International Reference Standard. The enhanced sensitivity was also demonstrated with 27 HBV seroconversion panels, detecting more panel members (191 of 364) vs. the ARCHITECT^® Qual I (144), Qual II (160) and PRISM^® (148) HBsAg assays. Further, the assay detected 7 of 12 HBV DNA positive/HBsAg negative samples, and detected all evaluated mutants and genotypes with higher sensitivity than the comparator assays. The improvement in sensitivity did not diminish assay specificity, attaining 100% (95% CI, 99.97-100%) on 10,633 blood donors.

CONCLUSIONS

An Abbott ARCHITECT^® HBsAg assay with clinical performance approaching that of mini-pool NAT (approximately 100 copies/ml was developed. The assay has superior HBsAg mutant and genotype detection and specificity, all of which are important for the diagnosis and management of HBV infection.

Infection prevention and the medical director: uncharted territory

Infections continue to be a major cause of disease and contributor to death in patients on dialysis. Despite our knowledge and acceptance that hemodialysis catheters should be avoided and eliminated, most patients who begin dialysis initiate treatment through a central vein hemodialysis catheter. Dialysis Medical Directors must be the instrument through which our industry changes. We must lead the charge to educate our dialysis staff and our dialysis patients. We must also educate ourselves so that we not only know that our facility policies are consistent with the best evidence available, but we must also know where local and federal regulations differ. When these differences impact on patient care, we must speak out and have these regulations changed. But it is not enough to know the rules and write them. We must lead by example and show our patients, our nephrology colleagues and our dialysis staff that we always follow these same policies. We need to practice what we preach and be willing and available to redirect those individuals who have difficulty following the rules. In order to effectively change process meaningful data must be collected, analyzed and acted upon. Dialysis Medical Directors must direct and lead the quality improvement process. We hope this review provides Dialysis Medical Directors with the necessary tools to effectively drive this process and improve care.