Evaluation of commercial SARS-CoV-2 serological assays in Canadian public health laboratories.

The COVID-19 pandemic has led to the influx of immunoassays for the detection of antibodies towards severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) into the global market. The Canadian Public Health Laboratory Network Serology Task Force undertook a nationwide evaluation of twelve laboratory and 6 point-of-care based commercial serological assays for the detection of SARS-CoV-2 antibodies. We determined that there was considerable variability in the performance of individual tests and that an orthogonal testing algorithm should be prioritized to maximize the accuracy and comparability of results across the country. The manual enzyme immunoassays and point-of-care tests evaluated had lower specificity and increased coefficients of variation compared to automated enzyme immunoassays platforms putting into question their utility for large-scale sero-surveillance. Overall, the data presented here provide a comprehensive approach for applying accurate serological assays for longitudinal sero-surveillance and vaccine trials while informing Canadian public health policy.

Comparison of Alinity m HPV and cobas HPV assays on cervical specimens in diverse storage media.

OBJECTIVE: To assess the concordance of high-risk HPV (HR-HPV) testing with the Alinity assay on cervical samples collected with diverse collection/storage protocols (ThinPrep, SurePath, Cervicollect) and to assess inter-assay concordance of HR-HPV testing of cervical cell specimens with Alinity m HR HPV assay (Alinity) vs cobas® 4800 HPV assay (cobas). METHODS: Specimens were obtained from 560 women attending a Women's Health clinic. Two specimens were obtained from each woman with combinations of two of the three collection devices and aliquots were tested by the two assays. RESULTS: Alinity showed an agreement of 93.9%, Kappa = 0.89 (263/280) between ThinPrep and SurePath specimens; 97.5%, Kappa = 0.95 (347/356) and 92.9%, Kappa = 0.85 (104/112) between ThinPrep and SurePath aliquots taken before or after cytology processing, respectively. Cervi-Collect specimens showed an agreement of 94.6%, Kappa = 0.89 (265/280) with ThinPrep specimens. Compared to cobas, Alinity showed agreements of 94.3%, Kappa = 0.88 (395/419) and 91.8%, Kappa = 0.82 (257/280) between ThinPrep and SurePath specimens, respectively. Alinity and cobas detected genotypes 16/18 and other high-risk HPV types at similar rates and showed similar correlations with cytology grades. CONCLUSIONS: Compared to cobas, Alinity performed equally well for detecting HPV in cervical specimens obtained with ThinPrep and SurePath. The Cervi-Collect device compared well to the other collection methods. Alinity is a reliable assay for simultaneous detection of HPV-16/18 and other high-risk genotypes in cervical specimens.

A Novel Small Molecule Inhibits Hepatitis C Virus Propagation in Cell Culture.

Hepatitis C virus (HCV) can cause acute and chronic infection that is associated with considerable liver-related morbidity and mortality. In recent years, there has been a shift in the treatment paradigm with the discovery and approval of agents that target specific proteins vital for viral replication. We employed a cell culture-adapted strain of HCV and human hepatoma-derived cells lines to test the effects of our novel small-molecule compound (AO13) on HCV. Virus inhibition was tested by analyzing RNA replication, protein expression, and virus production in virus-infected cells treated with AO13. Treatment with AO13 inhibited virus spread in cell culture and showed a 100-fold reduction in the levels of infectious virus production. AO13 significantly reduced the level of viral RNA contained within cell culture fluids and reduced the cellular levels of HCV core protein, suggesting that the compound might act on a late step in the viral life cycle. Finally, we observed that AO13 did not affect the release of infectious virus from infected cells. Docking studies and molecular dynamics analyses suggested that AO13 might target the NS5B RNA polymerase, however, real-time RT-PCR analyses of cellular levels of HCV RNA showed only an ∼2-fold reduction in viral RNA levels in the presence of AO13. Taken together, this study revealed that AO13 showed consistent, but low-level antiviral effect against HCV, although the mechanism of action remains unclear. IMPORTANCE The discovery of curative antiviral drugs for a chronic disease such as HCV infection has encouraged drug discovery in the context of other viruses for which no curative drugs currently exist. Since we currently face a novel virus that has caused a pandemic, the need for new antiviral agents is more apparent than ever. We describe here a novel compound that shows a modest antiviral effect against HCV that could serve as a lead compound for future drug development against other important viruses such as SARS-CoV-2.

Comparison of two automated instruments for Epstein-Barr virus serology in a large adult hospital and implementation of an Epstein-Barr virus nuclear antigen-based testing algorithm.

Serology remains the mainstay for diagnosis of Epstein-Barr virus (EBV) infection. This study compared two automated platforms (BioPlex 2200 and Architect i2000SR) to test three EBV serological markers: viral capsid antigen (VCA) immunoglobulins of class M (IgM), VCA immunoglobulins of class G (IgG) and EBV nuclear antigen-1 (EBNA-1) IgG. Using sera from 65 patients at various stages of EBV disease, BioPlex demonstrated near-perfect agreement for all EBV markers compared to a consensus reference. The agreement for Architect was near-perfect for VCA IgG and EBNA-1 IgG, and substantial for VCA IgM despite five equivocal results. Since the majority of testing in our hospital was from adults with EBNA-1 IgG positive results, post-implementation analysis of an EBNA-based algorithm showed advantages over parallel testing of the three serologic markers. This small verification demonstrated that both automated systems for EBV serology had good performance for all EBV markers, and an EBNA-based testing algorithm is ideal for an adult hospital.