Journal of clinical virology plus最新文献

Background

Differentiating between SARS-CoV-2 and Influenza (flu) A and B is often difficult without laboratory testing as the symptomology of these respiratory viral infections overlap.

Objective

Evaluate the clinical performance of the BD COR™ System multiplex assay (COR SC2/Flu) to detect the three viral pathogens using single nasopharyngeal (NP) swabs collected from symptomatic and asymptomatic individuals.

Materials and methods

Swabs collected from 203 symptomatic and 144 asymptomatic individuals were tested using COR SC2/Flu. Results were compared to those from the BioFire® Respiratory Panel 2.1 (BioFire RP2.1) and positive and negative percent agreements (PPA and NPA, respectively) with 95% confidence intervals were calculated.

Results

For asymptomatic individuals (n = 144), PPA between COR SC2/Flu and BioFire RP2.1 was 100% (95% CI: 79.6–100) and NPA was 97.7% (95% CI: 93.4–99.2) for the SARS-CoV-2 target. For symptomatic individuals (n = 203), PPA was 100% (95% CI: 92.9–100) and NPA 99.3% (95% CI: 96.4–99.9) for the SARS-CoV-2 target. PPA was 94.0% (95% CI: 83.8–97.9) and NPA was 98.7% (95% CI: 95.4–99.6) for the flu A target. PPA was 100% (95% CI: 92.9–100) and NPA was 100% (95% CI: 97.6–100) for flu B.

Conclusion

The continued development and validation of multiplex assays to detect SARS-CoV-2, flu A, and flu B should remain a crucial component of diagnostics as these viruses will continue to coexist in the post-pandemic environment. COR SC2/Flu assay performance met the predetermined clinical specifications for PPA and NPA for SARS-CoV-2, flu A, and flu B detection, and should help support infection control efforts of those diseases.

The demand for molecular virology testing continues to grow in clinical laboratories worldwide. The Alinity m system is a fully automated, continuous, random-access molecular diagnostic analyzer that was designed to streamline the laboratory workflow. In this study, we assessed the clinical performance characteristics of the Alinity m HCV and HIV-1 assays to detect and quantify these two bloodborne pathogens in 71 serum and plasma specimens. The overall qualitative agreement between the Alinity m and Abbott m2000 was 100 % for HCV and 94.4 % for HIV-1. Our data demonstrated a weak bias across the quantitative range of the Abbott m2000 and Alinity m HCV and HIV-1 assays, indicating a strong correlation on viral loads between them. Taken together, the Alinity m HCV and HIV-1 assays had comparable results to their current predecessors, the Abbott RealTime HCV and HIV-1 assays.

The pandemic of 2019 coronavirus disease (COVID-19) has become a world public health challenge. A new member of Coronaviridae family, named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been identified as the causative of COVID-19. Although SARS-CoV-2 infection has a direct impact on the respiratory function, extra-respiratory complications such as liver damage have been reported in some cases. However, the exact mechanisms of liver injury in SARS-CoV-2 infection remain largely unexplored. It has also been suggested that patients with pre-existing liver disease are significantly influenced by COVID-19. Considering the double burden of chronic liver diseases and SARS-CoV-2 on health systems, investigating the interrelationship between COVID-19 and underlying liver disease and providing clear recommendations on treatment are very much needed.

Viral hepatitis is recognized as one of the substantial risk factors for chronic liver diseases. Hepatitis B virus (HBV) is a main cause of liver failure, cirrhosis and hepatocellular carcinoma (HCC). Since both HBV and SARS-CoV-2 affect liver physiology, investigating the possible interactions and effects of SARS-CoV-2/HBV co-infection is increasingly important. This review highlighted the molecular and clinical consequences of SARS-CoV-2/HBV co-infection.

Introduction

While the global COVID-19 pandemic is slowly coming under control, current efforts are focused on understanding the epidemiology of endemic SARS-CoV-2. The tool of choice for doing so remains serological tests that detect SARS-CoV-2 induced antibodies. However, the performance of these tests should be evaluated to ensure they comply with the specific performance criteria desired by each country that they are used in.

Methods

Here, we use pre-COVID-19 plasma and plasma from SARS-CoV-2-infected individuals collected in 2020, 2021 and 2022 to evaluate the performance of two commercial Rapid Lateral Flow (RLF) tests (the PANBIO™ COVID-19 IgG/IgM rapid test and the LABNOVATION™ COVID-19 (SARS-CoV-2) IgG/IgM rapid test) and one commercial ELISA test (the PLATELIA™ SARS-CoV-2 total Ab).

Results

We find that whereas the specificity of the two RLF tests is ≥ 95%, it was 91% for the ELISA tests. However, at 14 days post-COVID-19 date of diagnosis (DoD), only the ELISA test constantly achieved a sensitivity of ≥80% over all the three years. In addition, the rate of detection of the two RLF tests varied across the years with a sensitivity ranging from <80% in 2021 to >80% in 2022. More importantly the capacity of these two RLF tests to detect IgG antibodies decreased with time. On the contrary, the sensitivity of the ELISA test was still above 80% more than six months post DoD.

Conclusion

We recommend that sero-epidemiological surveys focused on testing antibodies should not rely on performances reported by the assay manufacturers. They should include a formal evaluation of the selected assays to ensure its limitations and strengths conform with the data-accuracy requirements of the surveys.

Asymptomatic and presymptomatic patients played a critical role in the maintenance and spread of infection during COVID pandemic. However, conflicting views about the infectiousness of asymptomatic patients have been raised.

Identification of asymptomatic cases relies on SARS-CoV-2 genome detection and, in the absence of common epidemiological variables, quantification of viral load (VL) has been proposed as an estimator for SARS-CoV-2 transmission.

Comparison of VLs from symptomatic and asymptomatic patients displayed variable results according to the studied population, the experimental design and the sampling, among other variables.

The aim of this work was to determine VLs in symptomatic and asymptomatic patients at the time of sampling and to retrospectively determine their relationship with severity of disease and other parameters that affected the course of COVID-19, in two towns located in Buenos Aires, Argentina.

Results from our study showed that VLs from symptomatic and asymptomatic patients were significantly different when analyzed globally. In addition, significant differences were found when VLs from each COVID-19 wave were analyzed. In the first wave VLs from asymptomatic patients (log10 8,21 gc/µl) were significantly higher than in symptomatic ones (log10 6,51 gc/µl) while; in the second wave, VLs from asymptomatic patients resulted significantly lower than in symptomatic patients (log10 4,51 gc/µl and log10 5,23 gc/µl, respectively). In the third wave, no significant differences were observed between VLs from both types of patients.

Results from this work demonstrated that the screening of both symptomatic and asymptomatic patients was of utmost importance in order to reduce SARS-CoV-2 transmission to communities.

Background

The neurological manifestations of acute SARS-CoV-2 infection are well established, but limited understanding of the post-infectious neurological complications of COVID-19 (PINCC) contributes to significant morbidity and mortality. Hence in this study, we aimed to describe the clinical, radiological, and electrophysiological spectrum and outcome of PINCC from a tertiary referral center.

Methods

We identified 18 cases with diverse neurological manifestations following recovery from an acute SARS-CoV-2 infection. The neurological manifestations, magnetic resonance imaging findings of the brain and spinal cord, nerve conduction studies, and the treatment and outcome data were collected from electronic medical records.

Results

The mean age of presentation was 47± 18.5 years, and 11 patients (61 %) were male. For 11 (61 %) patients, prior COVID-19 symptoms were minimal or absent. The mean time to onset of neurological manifestations was 3 weeks after COVID-19 infection (range 1–8 weeks). 14 patients (77.8 %) had central nervous system (CNS) manifestations, and 4 (22.2 %) had peripheral nervous system (PNS) manifestations. The CNS manifestations included cerebrovascular events in 7, demyelination in 4, and aseptic meningitis, amnestic mild cognitive impairment, and disseminated tuberculosis in one case each. PNS manifestations were Guillain-Barré syndrome, mononeuritis multiplex, asymmetric polyradiculoneuropathy, and isolated diaphragm palsy in one patient each.

Conclusion

Post-infectious neurological complications of COVID-19 can involve both central and peripheral nervous system and is independent of the severity of acute infection.

Introduction

Higher antibody levels, in particular antibodies directed against the receptor-binding domain (RBD) of the spike protein, protect against re-infection with SARS-CoV-2. Quantitative antibody response data provide insight into population immunity and are essential for decision-making on booster-vaccination strategies. We aimed to identify predictors for higher antibody responses such as gender, age, experienced COVID-19-compatible symptoms, disease severity and exposure to pre-determined risk factors associated with SARS-CoV-2 seropositivity.

Materials and methods

Quantitative anti-S-RBD responses were analysed in seropositive vaccine-naive individuals (n = 1,857) from a study population of 10,001 adults, including healthcare workers (n = 211) and individuals with a known date of a positive PCR (n = 214). Regression models tested associations between age, gender, the period of symptoms, disease severity, pre-identified exposure factors associated with SARS-CoV-2 seropositivity, and anti-S-RBD responses.

Results

Symptoms of more severe disease (fever and/or dyspnoea: OR 2.42 [95%CI 1.76–3.34], and hospital admission: OR 11.41 [95%CI 4.66–27.97]), and a longer interval between COVID-19-compatible symptoms and serum collection (OR 3.17 [95%CI 1.32–7.63]) were predictive for anti-S-RBD levels ≥300 U/mL. Working in healthcare was inversely associated with anti-S-RBD levels ≥300 U/mL (OR 0.51 [95%CI 0.31–0.82]). None of the pre-identified exposure factors associated with SARS-CoV-2 seropositivity could be identified as predictive of higher anti-S-RBD responses.

Conclusion

No exposure factors were identified as predictors of higher neutralising antibody responses. Nevertheless, higher neutralising antibody levels in individuals with more severe symptoms suggest better immunological protection against SARS-CoV-2 re-infection. In seroprevalence studies, that mainly include asymptomatic or mildly infected individuals, the determination of quantitative antibody responses may help in the interpretation of population immunity.

Background

Early evidence suggested that the impact of the COVID-19 pandemic was less severe in Africa compared to other parts of the world. However, more recent studies indicate higher SARS-CoV-2 infection and COVID-19 mortality rates on the continent than previously documented. Research is needed to better understand SARS-CoV-2 infection and immunity in Africa.

Methods

In early 2021, we studied the immune responses in healthcare workers (HCWs) at Lagos University Teaching Hospital (n = 134) and Oxford-AstraZeneca COVID-19 vaccine recipients from the general population (n = 116) across five local government areas (LGAs) in Lagos State, Nigeria. Western blots were used to simultaneously detect SARS-CoV-2 spike and nucleocapsid (N) antibodies (n = 250), and stimulation of peripheral blood mononuclear cells with N followed by an IFN-γ ELISA was used to examine T cell responses (n = 114).

Results

Antibody data demonstrated high SARS-CoV-2 seroprevalence of 72·4% (97/134) in HCWs and 60·3% (70/116) in the general population. Antibodies directed to only SARS-CoV-2 N, suggesting pre-existing coronavirus immunity, were seen in 9·7% (13/134) of HCWs and 15·5% (18/116) of the general population. T cell responses against SARS-CoV-2 N (n = 114) were robust in detecting exposure to the virus, demonstrating 87·5% sensitivity and 92·9% specificity in a subset of control samples tested. T cell responses against SARS-CoV-2 N were also observed in 83.3% of individuals with N-only antibodies, further suggesting that prior non-SARS-CoV-2 coronavirus infection may provide cellular immunity to SARS-CoV-2.

Conclusions

These results have important implications for understanding the paradoxically high SARS-CoV-2 infection with low mortality rate in Africa and supports the need to better understand the implications of SARS-CoV-2 cellular immunity.

Background

Saliva has been considered a suitable sample material for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA testing, but uncertainty remained regarding sensitivity and reliability of different saliva collection methods.

Objectives

This study aimed to investigate the potential utility of expectorated saliva (ES) and drooled saliva (DS) for community mass testing.

Study design

Self-collected ES and DS samples were obtained in a prospective cohort study with 2,878 participants. The utility of saliva for SARS-CoV-2 qRT-PCR testing was assessed by comparing the capacity to detect SARS-CoV-2 positive cases with results for self-collected combined throat and nose (CTN) swabs. Additionally, quantification cycle (Cq) values were compared.

Results

ES- and DS-based tests showed the same high level of concordance (98% vs 98%) with CTN swab-based results. Sensitivity was higher for DS (94%) than for ES (83%) or CTN swab (90%) but differences were statistically not significant. Comparing only symptomatic cases, however, a significantly higher sensitivity of DS (96%) than of ES (76%) or CTN swab (91%) was observed. Cq values of saliva and swab specimen were significantly correlated and appeared to be not impacted by age or other potentially confounding factors.

Conclusions

Saliva-based SARS-CoV-2 RNA testing showed high diagnostic accuracy and can be considered an alternative where swabbing may not be tolerated or operationally feasible. DS yielded the same or better diagnostic performance compared to ES and may present a preferred option with reduced aerosol risk and increased compliance.