1,721,010 research outputs found
Diagnostic accuracy of a SARS-CoV-2 rapid antigen test in real-life clinical settings.
Get PDFBACKGROUND
Laboratory tests are a mainstay in managing the COVID-19 pandemic, and high hopes are placed on rapid antigen tests. However, the accuracy of rapid antigen tests in real-life clinical settings is unclear because adequately designed diagnostic accuracy studies are essentially lacking.
OBJECTIVES
We aimed to assess the diagnostic accuracy of a rapid antigen test to diagnose SARS-CoV-2 infection in a primary/ secondary care testing facility.
METHODS
Consecutive individuals presented at a COVID-19 testing facility affiliated to a Swiss University Hospital were recruited (n=1'465%). Nasopharyngeal swabs were obtained, and the Roche/ SD Biosensor rapid antigen test was conducted in-parallel with two real-time PCR (reference standard).
RESULTS
Among 1'465 patients recruited, RT-PCR was positive in 141 individuals, corresponding to a prevalence of prevalence 9.6%. The Roche/ SD Biosensor rapid antigen test was positive in 94 patients (6.4%), and negative in 1'368 individuals (93.4%). The overall sensitivity of the rapid antigen test was 65.3% (95% confidence interval, CI, 56.8, 73.1), the specificity was 99.9% (95%CI 99.5, 100.0). In asymptomatic individuals, the sensitivity was 44.0% (95%CI 24.4, 65.1).
CONCLUSIONS
The diagnostic accuracy of the SARS-CoV-2 Roche/SD Biosensor rapid antigen test to diagnose a SARS-CoV-2 infection in a primary/ secondary care testing facility was considerably lower compared to manufacturers' data. Widespread application in this setting might lead to a considerable number of individuals falsely classified as SARS-CoV-2 negative
Diagnostic accuracy of SARS-CoV-2 saliva antigen testing in a real-life clinical setting.
Get PDFBACKGROUND
SARS-CoV-2 antigen tests with saliva facilitate examination in settings that lack trained personnel. However, little is known on the diagnostic accuracy in real-life clinical settings. Therefore, we studied the diagnostic accuracy of a saliva antigen test to diagnose SARS-CoV-2 infection in a primary/ secondary care testing facility.
METHODS
Individuals presented at a COVID-19 testing facility affiliated with a Swiss University Hospital were prospectively recruited (n=377). Saliva specimen was obtained, and the PCL Inc. COVID19 Gold antigen test was conducted in parallel with two real-time PCR.
RESULTS
RT-PCR was positive in 53 individuals, corresponding to a prevalence of 14.1% (missing material in one individual). The PCL saliva antigen test was positive in 22 individuals (5.8%), and negative in 354 (93.9%). The sensitivity of the saliva antigen test was 30.2% (95% confidence interval, CI, 18.3 to 44.3), both overall and in symptomatic individiduals. The specificity was 98.1% (96.0, 99.3).
CONCLUSIONS
The diagnostic accuracy of a SARS-CoV-2 saliva antigen test in a primary/ secondary care testing facility was remarkably lower compared to the manufacturers' specifications. Keywords Infections/*epidemiology/transmission; severe acute respiratory syndrome coronavirus 2 [Supplementary Concept]; COVID-19 diagnostic testing [Supplementary Concept] Background
IGRA-positive patients and interferon-gamma/interleukin-2 signatures: can the Fluorospot assay provide further information?
Get PDFA goal of testing for latent tuberculosis (TB) infection is to identify individuals who are at increased risk for the development of active TB. No laboratory tool is currently available to distinguish between individuals in the process of progressing from latent TB infection towards active disease and those who are not. Determination of the interferon-gamma and interleukin-2 T cell signature might provide an additional and rapid tool to evaluate treatment necessity and clinical management of a patient. Here, we present three cases of interferon-gamma release assay-positive patients with differing interferon-gamma and interleukin-2 signatures when analyzed by the Fluorospot assay
Epidemiology of Human Adenoviruses: A 20-Year Retrospective Observational Study in Hospitalized Patients in Bern, Switzerland.
Get PDFBackground
Human adenovirus (HAdV) is an important pathogen seen in clinical practice. Long-term studies may help better understand epidemiological trends and changes in circulating genotypes over time.
Purpose
Using a large biobank of samples from hospitalized, adenovirus-positive patients over a 20-year period, we aimed to analyze long-term epidemiological trends and genotypic relatedness among circulating HAdV strains.
Methods
Based on samples from hospitalized patients confirmed to be HAdV positive in Bern, Switzerland, from 1998 to 2017, and on their associated demographic and clinical data, we identified epidemiological trends and risk factors associated with HAdV infection. HAdV genotyping was performed by PCR amplification and sequencing of the hypervariable hexon gene. The obtained sequences were phylogenetically compared with sequences from international HAdV strains.
Results
HAdV was identified in 1302 samples tested. Cases of HAdV infection were reported throughout the years with no clear seasonality. Upper respiratory tract samples, conjunctivitis swabs, and stool had the highest positivity rate (56.2%, 18.7%, and 14.2% of the cases, respectively). HAdV infection was highest among children ≤4 years old. Increased number of HAdV cases were observed in years 2009 (n = 110) and 2010 (n =112). HAdV8 was the predominant genotype among patients older than 20 years, and was mostly associated with ophthalmic infection. Predominant genotypes among children ≤4 years old were HAdV1, HAdV2, and HAdV3, which were mostly associated with respiratory tract infections. Recurring peaks of increased HAdV cases were evidenced every 4 years among children ≤4 years old.
Conclusion
Our study gives novel insights on long-term epidemiological trends and phylogenetic relatedness among circulating HAdV strains in Switzerland, country in which little data on HAdV prevalence and diversity was so far available
Evaluation of the DiaSorin LIAISON SARS-CoV-2 antigen assay on nasopharyngeal swabs in two different SARS-CoV-2 pandemic waves in Switzerland: The impact of the Omicron variant on its performance.
Get PDFBackground
SARS-CoV-2 antigen tests reliably detect individuals with high viral loads and provide an efficient diagnostic tool to manage the current SARS-CoV-2 pandemic. However, mutations in SARS-CoV-2 variants of concerns that appeared after validation of most antigen tests might impact their diagnostic performance.
Objectives
To assess the impact of the Omicron variant on the performance of the DiaSorin LIAISON SARS-CoV-2 antigen test, we evaluated its sensitivity and specificity on nasopharyngeal swabs (NPS) compared to rRT-PCR in the second and the Omicron pandemic wave in Switzerland.
Study design
A random selection of NPS from patients undergoing SARS-CoV-2 diagnostics by rRT-PCR were collected during the second and the Omicron pandemic wave and further analyzed by the LIAISON antigen test. Sensitivity and specificity compared to rRT-PCR were calculated.
Results
Test performance did not change in the two investigated periods. The overall sensitivity of 75.8% in the second and 76.5% in the Omicron wave increased to 87.1% and 88.4%, excluding samples with rRT-PCR Ct-value >30. By lowering the cut-off from 200 TCID50/ml to 62 TCID50/ml to discriminate between negative and positive samples using a ROC-curve, the sensitivity resulted in 88.8% for the second and 93.3% for the Omicron pandemic wave. The specificity of the LIAISON antigen test was 100% in both collectives.
Conclusion
Omicron variant does not seem to affect the performance of the LIAISON antigen test. The WHO recommended sensitivity of ≥80% for antigen testing was fulfilled during both pandemic periods in samples with Ct-value <30 or by optimizing the assay cut-off
Long-term sequelae after viral meningitis and meningoencephalitis are frequent, even in mildly affected patients, a prospective observational study
Get PDFIntroduction: An increasing number of studies demonstrate that viral meningitis and meningoencephalitis, even those with a mild course of meningitis, can result in residual sequelae.
Methods: We aimed to investigate the long-term outcome in both viral meningitis and meningoencephalitis/encephalitis patients and impact of long-term sequelae on patients’ social and professional daily lives in a prospective observational study with a follow-up period of 20 months.
Results: A total of 50 patients (12% encephalitis, 58% meningoencephalitis and 30% meningitis) and 21 control persons participated in the study. The most common cause was the tick-borne encephalitis (TBE) virus. The most important persistent signs and symptoms after 2 years were subjective cognitive impairment (36%), fatigue and/or excessive daytime sleepiness (31%), disturbed nighttime sleep (31%) and headaches (13%), as well as feeling more rapidly exhausted after cognitive effort (53%). Independent of disease severity in the acute phase, almost one third of patients still reported mildly impaired social and/or professional life due to the long-term sequelae, with scores in the health status assessment still significantly lower compared to healthy controls.
Discussion: Regardless of the severity of the acute illness and despite constant improvement within 2 years, 67% of patients still had persistent signs and symptoms, but these were only relevant to everyday social or professional life in about 30% of these patients
Do all Emergency Room Patients With Influenza-like Symptoms Need Blood Cultures? A Retrospective Cohort Study of 2 Annual Influenza Seasons.
Get PDFIn this retrospective cohort study, we evaluated risk factors for bacteremia in emergency department patients presenting with influenza-like symptoms during influenza epidemic seasons. In patients without fever, chronic heart or chronic liver disease, blood culture collection might be omitted
Phenotypic testing of patient herpes simplex virus type 1 and 2 isolates for acyclovir resistance by a novel method based on real-time cell analysis.
No full textBACKGROUND
Acyclovir (ACV) is the most commonly used drug for herpes simplex virus (HSV) infection therapy. Prolonged antiviral therapy or prophylaxis in immunocompromised patients may promote the development of drug-resistant strains. Due to the high polymorphism in genes involved in drug resistance, phenotypic methods, although work-intensive, are still required to test drug susceptibility. Real-time cell analysis (RTCA) based methods could offer a rapid and less labor-intensive alternative for phenotypic testing of ACV resistance.
OBJECTIVE
To investigate the utility of a new RTCA based assay (RTCAA) to test acyclovir susceptibility of HSV clinical isolates.
STUDY DESIGN
Four reference strains and 93 clinical isolates (60 HSV-1 and 33 HSV-2) were tested by RTCAA. In the presence of ACV concentrations from 2.2 to 140.8 μM, Vero cells were infected with different virus dilutions. IC50 values were calculated by dose-response curve (DRC) with area-under-curve (AUC) method. The reference strains and 22 clinical isolates were additionally tested by dye-uptake assay, and IC50 values of both methods were compared.
RESULTS
IC50 values from RTCAA and dye-uptake assays were positively correlated (Spearman's rho = 0.897, p < 0.001) and quantitatively agreed (Bland-Altman plot). Based on a cut-off of 4 μM for HSV-1 and 13 μM for HSV-2, 87 isolates were classified as ACV-sensitive and 6 isolates as ACV-resistant. The reference strains showed the expected results of ACV susceptibility.
CONCLUSION
RTCAA agrees well with the dye-uptake assay. Compared with other phenotypic methods, RTCAA requires less manipulation, reduces the workload and the turnaround time, and appears to be an objective and reliable method to test ACV susceptibility
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