Journal of Clinical Virology最新文献

Background

Reliable and fast detection and quantification of human cytomegalovirus (CMV) DNA in various diagnostic specimens is essential for care of immunocompromised or congenitally infected individuals.

Objectives

To evaluate the analytical and clinical performance of the Panther Aptima® CMV (Hologic) quantitative real-time transcription mediated amplification (TMA) assay.

Study design

Performance of the TMA assay run on the Hologic Panther Fusion was analysed for 32 proficiency testing samples and 21 quantitative reproducibility panel samples; additionally, we compared results of TMA assay and routine quantitative real-time PCR assays ("PCR-A"= Biomérieux CMV R-gene® or "PCR-B"= Laboratory-developed CMV-PCR) in 518 diagnostic specimens (254 plasma, 120 EDTA whole blood, 43 urine, 45 amniotic fluid and 56 breast milk) at two university hospital laboratories.

Results

All proficiency panel samples were correctly identified and quantified by the TMA assay; replicate testing of the reproducibility panel samples showed good reproducibility within and between the two laboratories. Sensitivity in plasma and WB was higher for the TMA assay detecting low-level CMV-DNAemia in samples tested negative by routine PCR. Quantitative CMV-DNAemia values correlated well between TMA and real-time PCR. Similarly, urine, AF and BM specimens showed a high rate of concordant results (91%, 98% and 98%, respectively) among TMA and PCR with good correlation of quantitative values.

Conclusion

The performance of the Aptima® CMV TMA assay for viral blood load testing compared well to established real-time PCRs. In addition, it can be useful for diagnostics in urine, amniotic fluid and breast milk specimens.

Human papillomavirus (HPV)-based screening offers better protection against cervical cancer compared to cytology, but HPV screening assays must adhere to validation requirements of the international guidelines to ensure optimal performance. Allplex HPV HR Detection (Allplex) assay, launched in the late 2022, is a fully automated real-time PCR-based assay utilizing innovative technology that enables quantification and concurrent distinction of 14 high-risk HPV genotypes (HPV16,18,31,33,35,39,45,51,52,56,58,59,66 and 68). We assessed the validity of the Allplex for cervical cancer screening purposes, via comparison to a clinically validated comparator assay (Hybrid Capture 2; HC2), and through assessment of intra-laboratory reproducibility and inter-laboratory agreement. A clinical validation panel comprised of 973 residual ThinPrep samples was obtained from women aged 30-64 years participating in the organized Slovenian screening program, of these 863 were from women undergoing their regular screening visit after a previous negative screen test while 110 were from women with underlying cervical intraepithelial neoplasia grade 2 or worse (CIN2+) lesions. The Allplex's relative clinical sensitivity for detection of CIN2+ and CIN3+ were 1.01 (95%CI;0.98-1.04) and 0.98 (95%CI;0.95-1.02), compared to that of HC2. At recommended thresholds of ≥98% and ≥90%, the Allplex's clinical sensitivity and specificity (p=0.0004 and p=0.02, respectively) were non-inferior to HC2. High intra-laboratory reproducibility and inter-laboratory agreement, both overall (98.1% and 97.9%, respectively) and at genotype level (>98.7%) was observed. In addition, analytical genotype-specific performance of Allplex was compared to that of its predecessor Anyplex HPV HR; high overall agreement was observed (96.3%; kappa value 0.88), with some variations in performance. In conclusion, Allplex met all validation criteria described in the international guidelines on sensitivity, specificity and laboratory reproducibility and can be considered clinically validated for primary cervical cancer screening.

Background

Cytomegalovirus (CMV) can cause a wide panel of ocular infections. The involvement of CMV as a cause of anterior uveitis in the immunocompetent patient is recent and remains poorly understood.

Objective

To investigate the presence of CMV in anterior uveal tissues of immunocompetent corneal donors.

Study Design

We collected aqueous humor, iris, and ciliary body from both eyes of 25 donors died at the Limoges University Hospital between January 2020 and July 2021. CMV serology was determined for all patients from post-mortem blood sample. Ocular tissues were split in 2 fragments for qPCR and 2 for histological analysis. CMV genomes copies were quantified by Multiplex qPCR after DNA extraction.

Results

16 of 25 patients (64%) displayed positive CMV serology, with a median age of 67 years. Viremia was positive in 3 of 16 (19%) CMV-positive patients. No CMV DNA copies were found from the aqueous humor samples. CMV DNA was detected in iris and ciliary body of 28 of 32 eyes of seropositive donors, and 5 of 18 eyes of seronegative donors. The median viral copy number [IQR] was 2.41 × 10² [8.91 × 10¹ - 1.01 × 10³] copies/1 × 10⁶ cells in the CMV-positive group and 0.00 [0.00 - 3.54 × 10²] copies/1 × 10⁶ cells in the CMV-negative group (p<0.001). Histology and immunohistochemistry did not reveal any CMV lesions from any sample.

Conclusion

CMV DNA was found in iris and ciliary body of immunocompetent seropositive patients, but also, although less frequently, from seronegative donors. These results highlight mechanisms of infection, latency and reactivation of CMV in ocular tissues.

Background

Respiratory syncytial virus (RSV) causes lower respiratory tract infections (LRTI) that may lead to hospitalization or death. The present study aimed to assess the burden of RSV infections in hospitalized adults.

Methods

RSV-related hospitalizations were identified from the nationwide hospital claims database in France (PMSI) from 2012 to 2021 using ICD-10 codes J12.1, J20.5, J21.0 or B97.4, and outcomes assessment focused on 2016–2020. In-hospital outcomes included length of stay, need for intensive care (ICU) and in-hospital all-cause mortality. Post-discharge outcomes included 30-day readmission for decompensation, 90-day RSV-related readmission, and 30 and 60-day in-hospital mortality.

Results

A cumulated number of 17 483 RSV-related stays were identified representing a rate of 72.0 cases per million stays. The outcomes assessment included 12,987 patients: 55.8 % were females and the mean age was 74.1 ± 16.4 years, with 57 % ≥ 75 years. Most of patients (78.6 %) had at least one comorbidity, mainly chronic respiratory (56.3 %) and cardiovascular diseases (41.3 %), or diabetes (23.5 %). A co-infection was found in 22.4 %, primarily bacterial (12 %). The mean length of stay was 12.3 ± 13.1 days. Overall, 10.9 % were admitted to an ICU and in-hospital mortality was 7.3 %. In-hospital outcomes were higher in cases of co-infection. Among 12 033 patients alive at discharge from the index stay, 6.5 % were readmitted with RSV within 90 days, 8.1 % for decompensation within 30 days, and 5.6 % died within 60-day.

Conclusion

This study demonstrated the high burden of RSV infections in older adults and those with chronic conditions, and the need for preventive strategies.

Background

Prompt identification of patients with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection on admission to hospital is crucial to ensuring initiation of appropriate treatment, optimising infection control and maintaining patient flow. The Abbott ID NOW™ COVID-19 assay (ID NOW) is a point-of-care, isothermal nucleic acid amplification test, capable of producing a result within minutes, potentially placing it as an invaluable tool in helping to control the coronavirus-disease 2019 (COVID-19) pandemic.

Objectives

To evaluate the diagnostic accuracy of ID NOW in acute hospital admissions.

Study design

A prospective approach to data collection was undertaken in consecutive patients with ID NOW and Hologic Aptima™ SARS-CoV-2 transcription-mediated amplification assay (Aptima TMA) results, across three hospitals in the south-west of England between 1st March and 30th September 2021. A nasal swab was taken for ID NOW and a combined nose and throat swab for Aptima TMA. Measures of diagnostic accuracy were calculated for ID NOW against Aptima TMA. This study was conducted during a period of alpha and delta strain predominance.

Results

19,698 ID NOW assays were performed, of which 12,821 had an Aptima TMA assay performed within 24 hours. ID NOW had sensitivity of 85.2 % (95 % CI, 82.2–87.9) and specificity of 99.6 % (95 % CI, 99.4–99.7) compared with the reference assay. The overall PPV was 91.0 % (95 % CI, 88.5–93.0) and the overall NPV was 99.3 % (95 % CI, 99.1–99.4).

Conclusions

ID NOW offers a valid diagnostic tool to detect SARS-CoV-2, performing comparably to a reference laboratory-based assay which takes longer to provide results.

West Nile Virus (WNV) causes a serious public health concern in many countries around the world. Virus detection in pathological samples is a key component of WNV infection diagnostic, classically performed by real-time PCR. In outbreak situation, rapid detection of the virus, in peripheral laboratories or at point of care, is crucial to guide decision makers and for the establishment of adequate action plans to prevent virus dissemination. Here, we evaluate a Loop-mediated isothermal amplification (LAMP) tool for WNV detection. Amplifications were performed comparatively on extracted viral RNA and on crude samples using a classical thermal cycler and a portable device (pebble device). qRT-PCR was used as gold standard and two sets of urine samples (n = 62 and n = 74) were used to evaluate the retained amplification protocols and assess their sensitivity and specificity. RT-LAMP on RNA extracts and crude samples showed a sensitivity of 90 % and 87 %, respectively. The specificity was 100 % for extracts and 97 % for crude samples. Using the device, the RT-LAMP on extracted RNA was comparable to the gold standard results (100 % sensitivity and specificity) and it was a bit lower on crude samples (65 % sensitivity and 94 % specificity). These results show that RT-LAMP is an efficient technique to detect WNV. RT-LAMP provides a rapid, sensitive, high-throughput and portable tool for accurate WNV detection and has potentials to facilitate diagnostic and surveillance efforts both in the laboratory and in the field, especially in developing countries.

Background

Cell-associated HIV-1 DNA, HIV-1 2-LTR circle, and HIV-1 unspliced RNA (usRNA) are important virological parameters for monitoring HIV-1 persistence and activation of latent HIV-1. Assays fully validated by CLIA and/or GCLP standards are needed for future clinical trials that seek to evaluate treatments directed towards HIV-1 cure.

Objectives

To determine performance characteristics of sensitive, moderate-throughput, digital droplet PCR (ddPCR) assays for cell-associated HIV-1 DNA, HIV-1 2-LTR circle, and HIV-1 usRNA that can detect a broad range of HIV-1 M-group subtypes.

Study Design

To evaluate linearity, limit of detection, precision, and accuracy of each assay, contrived specimens were analyzed in a background of uninfected PBMC. Detection breadth was evaluated by in silico analysis of primer and probes sets and analysis of material harvested from PBMC infected in vitro with various HIV-1 subtypes. A cohort of clinical specimens from viremic and virologically suppressed individuals was analyzed to demonstrate applicability to clinical research.

Results

The empirically determined limit of detection of these assays was 29, 7, and 60 copies per million PBMC for HIV-1 DNA, HIV-1 2-LTR circle, and HIV-1 usRNA, respectively. The assays detect a broad range of HIV-1 M-group subtypes. Finally, analysis of clinical specimens demonstrate that these assays can detect low levels of cell-associated HIV-1 DNA, HIV-1 usRNA, and HIV-1 2-LTR circle and correlate with clinical histories and viral loads of untreated and antiretroviral treated individuals.

Conclusions

We report the clinical validation of three HIV reservoir assays with broad HIV-1 coverage for future cure studies.

Background

Natural SARS-CoV-2 infection may elicit antibodies to a range of viral proteins including non-structural protein ORF8. RNA, adenovirus vectored and sub-unit vaccines expressing SARS-CoV-2 spike would be only expected to elicit S-antibodies and antibodies to distinct domains of nucleocapsid (N) protein may reliably differentiate infection from vaccine-elicited antibody. However, inactivated whole virus vaccines may potentially elicit antibody to wider range of viral proteins, including N protein. We hypothesized that antibody to ORF8 protein will discriminate natural infection from vaccination irrespective of vaccine type.

Methods

We optimized and validated the anti-ORF8 and anti-N C-terminal domain (NCTD) ELISA assays using sera from pre-pandemic, RT-PCR confirmed natural infection sera and BNT162b2 (BNT) or CoronaVac vaccinees. We then applied these optimized assays to a cohort of blood donor sera collected in April-July 2022 with known vaccination and self-reported infection status.

Results

We optimized cut-off values for the anti-ORF8 and anti-N-CTD IgG ELISA assays using receiver-operating-characteristic (ROC) curves. The sensitivity of the anti-ORF8 and anti-N-CTD ELISA for detecting past infection was 83.2% and 99.3%, respectively. Specificity of anti-ORF8 ELISA was 96.8 % vs. the pre-pandemic cohort or 93% considering the pre-pandemic and vaccine cohorts together. The anti-N-CTD ELISA specificity of 98.9% in the pre-pandemic cohort, 93% in BNT vaccinated and only 4 % in CoronaVac vaccinated cohorts. Anti-N-CTD antibody was longer-lived than anti-ORF8 antibody after natural infection.

Conclusions

Anti-N-CTD antibody assays provide good discrimination between natural infection and vaccination in BNT162b2 vaccinated individuals. Anti-ORF8 antibody can help discriminate infection from vaccination in either type of vaccine and help estimate infection attack rates (IAR) in communities.

Introduction

Laboratory diagnosis of measles can be challenging, and the reintroduction of the measles virus in Brazil has brought about new issues. The aim of this study was to analyze the qPCR results of swab and urine samples and compare them with those of immunological methods for the diagnosis of measles.

Methods

This was a cross-sectional study based on a retrospective analysis of 3,451 suspected cases using laboratory test surveillance databases for qPCR (respiratory swabs and urine) and serologic tests for IgM and paired IgG. Sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and agreement through kappa and adjusted kappa coefficients (PABAK) were calculated using different diagnostic strategies.

Results

The swab and urine samples obtained using real-time qPCR were equivalent. Samples collected simultaneously and the combined samples showed moderate agreement between IgM ELISA and real-time qPCR; however, 48.9 % of the IgM ELISA analyses did not demonstrate detectable qPCR concentrations during simultaneous collections and 43.9 % of combined collections. The paired analysis of IgG showed an accuracy of 67.5 % for IgM and 90.7 % for real-time qPCR.

Conclusions

Diagnosis based on IgM presents detection delimitation in samples collected early (1–5 days), suggesting that these individuals satisfy at least two criteria. In addition to qPCR, paired analysis of IgG using ELISA can be used to increase the sensitivity and specificity of laboratory diagnoses.

Background

Estimating HIV-1 recency of infection for incidence and local outbreaks detection usually involves specifically designed assays. Here, we established an approach to identify recent infections, estimate their rate, and assess potential risk factors.

Methods

Randomly selected HIV-1 positive samples (n = 382) collected in 2017–2021 were tested by Sedia and compared to the results of Geenius recency algorithm and the S/CO values of the HIV-1/2 Combo assay. Using Geenius and Combo recency verdict, we assessed all cases diagnosed in 2017–2021. Related factors were further assessed.

Results

While Geenius and Combo had a sensitivity of 65.9 % and 89.30 %, respectively, and specificity of 96 % and 90 %, respectively, compared to Sedia, higher concordance (97.2 %) and kappa (>0.9) were observed when the verdict of both assays together was compared to Sedia. Using this approach, 15.3 % (238/1548) of individuals diagnosed in 2017–2021 were defined as recently infected. In multivariate analysis, recent diagnosis was mainly associated with men who have sex with men (MSM) and with birthplace in Israel, Western/Central Europe, or North America.

Conclusions

Only 15.3 % of infections in 2017–2021, mainly in MSM and Israeli/Western countries-born individuals, were diagnosed early. Regular diagnostic assays have a potential to identify and monitor trends in recent infections.