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The diagnostic accuracy of the Elecsys® HCV Duo antigen-antibody combination immunoassay (Roche Diagnostics GmbH) was evaluated for the detection of hepatitis C virus (HCV) infection, versus commercially available comparators.This multicenter study (August 2020-March 2021) assessed the specificity of the Elecsys HCV Duo immunoassay and comparator assays in blood donor and routine clinical laboratory samples; sensitivity was determined in confirmed HCV-positive samples and seroconversion panels. The Elecsys HCV Duo immunoassay was compared with the Monolisa HCV Ag-Ab ULTRA V2, Murex HCV Ag/Ab Combination and ARCHITECT HCV Ag assays, as well as nucleic acid testing (NAT). The antibody (anti-HCV) module of the Elecsys HCV Duo immunoassay was compared with the Elecsys Anti-HCV II, Alinity s Anti-HCV, ARCHITECT Anti-HCV and RIBA HCV 3.0 SIA assays.The specificity of the Elecsys HCV Duo immunoassay was 99.94% (95% confidence interval [CI], 99.89-99.97) and 99.92% (95% CI, 99.71-99.99) in blood donor (n = 20,634) and routine clinical laboratory samples (n = 2531), respectively. The specificity of the Elecsys HCV Duo immunoassay was similar or better than comparator assays. The sensitivity of the Elecsys HCV Duo immunoassay in confirmed HCV-positive samples (n = 257) was 99.6%. In seroconversion panels, the Elecsys HCV Duo immunoassay detected infections earlier (2.2-21.9 days) than all but one of the comparator assays and detected HCV 1.8 days later than NAT.The Elecsys HCV Duo immunoassay shows high diagnostic accuracy, reduces the diagnostic window, and could be used when NAT is not possible.

Anti-hepatitis A virus (HAV) antibody titers at 20 IU/L are assumed to correlate with protection against HAV challenge.We examined the accuracy and precision of currently in use immunoassays for total or anti-HAV IgG determination, by repeated testing of dilutions of the international anti-HAV standard, within a 10-50 IU/mL concentration range.Eight immunoassays were evaluated. All could confidently identify people who need to be vaccinated, or who might benefit from a booster vaccine: no positive interpretation for the 10 and 15 IU/mL concentrations. However, qualitative interpretation may differ from test to test in the 15-30 IU/mL range. This variation has to be taken into account when comparing seroprevalence data.

BACKGROUND: Rapid diagnostic tests (RDT) have been developed for the detection of hepatitis B surface antigen (HBsAg). They represent a promising alternative to enzyme immunoassays and a powerful tool for large-scale screening and diagnosis of HBV infection, especially in regions without easy access to serological and molecular testing. OBJECTIVES: The aims of the present study were to evaluate the characteristics and clinical performance of a new CE-marked HBsAg RDT, DRW-HBsAg v2.0 assay (Diagnostics for the Real World™, Ltd., USA), in various patient populations, including those chronically infected with HBV, patients with severe acute hepatitis of unknown origin and pregnant women with unknown HBV serological status at delivery. RESULTS: The lower limit of detection of the assay, evaluated in 21 clinical samples, ranged from 0.30±0.07 to 0.97±0.26 international units/mL (using Abbott Architect as a reference), depending on the HBV genotype. The assay tested positive in 100% of patients with chronic hepatitis B, 96.3% of HBsAg-positive acute hepatitis patients, and 95.2% of HBsAg-positive pregnant women. Its specificity was 98.8% in HBsAg-negative patients, 98.7% in HBsAg-negative patients with acute hepatitis of unknown origin and 97.8% in HBsAg-negative pregnant women. Amino acid substitutions in the HBsAg major hydrophilic region did not affect HBsAg detection by DRW-HBsAg v2.0. CONCLUSIONS: The new DRW-HBsAg v2.0 assay is a simple, rapid, easy-to-run and highly sensitive assay that can be used in both high- and low-risk populations for the diagnosis of HBsAg carriage. It appears to be a promising new tool for large-scale screening and diagnosis of HBV infection.

Background In France, there are no consistent data estimating hepatitis delta virus (HDV) prevalence in the general population. Objectives To better characterize HDV/HBV infection and its trends over a 15-years period from 1997 to 2011, we used data retrieved from the National Epidemiological Donors database including viral and demographic characteristics of all French HBV infected blood donors. Study design Of the 39,911,011 donations collected over the 15 year-study-period, 6214 (1.56 in 10 4 donations) were confirmed positive for HBV from which 72.3% were tested for HDV antibodies (Ab). HDV viral load was performed using a real-time PCR assay on positive HDV Ab samples and HDV genotype determined for each positive viremic sample. Results Among the 4492 HBV donations, 89 (1.98%) were HDV Ab positive. After being stable around 1.1% from 1997 to 2005, this rate has continuously increased to reach 6.5% in 2010, before declining to 0.85% in 2011. Of the 61 investigated HDV Ab positive individuals, 22.9% were viremic with a viral load ranging from 10 4 to 9.8 × 10 7 copies mL −1 . Genotyping revealed 12 HDV-1, 1 HDV-6 and 1 HDV-7 in accordance with the geographical origin of individuals. Conclusion Such a study gives unexpected features of HBV–HDV infection in the population of blood donors which is a priori, a healthy population. The increase of HDV prevalence mainly linked to migration of population from endemic countries, demonstrates that there is still no complete control of HBV infection and must encourage HBV vaccination campaigns and systematic screening for HDV in HBV-infected.