Diagnostic Microbiology and Infectious Disease

BackgroundThe adoption of saliva as a specimen type for SARS-CoV-2 mass surveillance can significantly increase population compliance with decreased exposure risk for healthcare workers. However, studies evaluating the clinical performance of saliva compared to nasopharyngeal swab (NPS) samples have demonstrated conflicting results regardless of the collection being in healthcare or community settings. Further, pooled testing with saliva remains a challenge owing to the ambiguous sensitivity, li...

The SARS-CoV-2 pandemic has profoundly impacted communities across the globe, requiring accurate and accessible diagnostic technologies in support of public health mitigation efforts. As testing has evolved throughout the course of the pandemic, varying sample preparation methodologies have been employed. Herein we perform a comparison of three commercial sample preparation methods: two mechanical homogenization workflows and one enzymatic digestion approach for the detection of SARS-CoV-2 from ...

Prompt communication of critical laboratory results is important for patient safety. Various standardisation bodies have proposed procedures for handling critical results, with notification parameters outlined. However, few studies exist in low- and middle-income countries (LMIC) to document how critical results are handled. We tracked 12 types of laboratory tests over a three-week period in December 2018 and documented if and how critical test results were communicated, the time-frame for commu...

The COVID-19 pandemic highlighted the need for effective protection and rapid development of tests to track and quantify seroconversion through natural infection and vaccination. Recombinant proteins, consisting of the SARS-CoV-2 nucleocapsid and Spike Receptor Binding Domains (RBD) fused with nanoluciferase reporters (GloBodies) were designed and produced. The SARS-CoV-2 specific antibody within serum, from venous blood or eluted from local or remotely-obtained dried blood spots, form a complex...

With surging global demand for increased SARS-CoV-2 testing capacity, clinical laboratories seek automated, high-throughput molecular solutions, particularly for specimen types which do not rely upon supply of specialized collection devices or viral transport media (VTM). Saliva was evaluated as a diagnostic specimen for SARS-CoV-2 using the cobas(R) SARS-CoV-2 Test on the cobas(R) 6800 instrument. Saliva specimens submitted from various patient populations under investigation for COVID-19 from ...

IntroductionEarly differentiation between emergency department (ED) patients with and without corona virus disease (COVID-19) is very important. Chest CT scan may be helpful in early diagnosing of COVID-19. We investigated the diagnostic accuracy of CT using RT-PCR for SARS-CoV-2 as reference standard and investigated reasons for discordant results between the two tests. MethodsIn this prospective single centre study in the Netherlands, all adult symptomatic ED patients had both a CT scan and a...

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has presented significant challenges for laboratories including supply chain limitations with restricted access to reagents and sample collection materials (i.e. swabs, viral transport media (VTM)) for patients testing. Therefore, saliva has been evaluated as an alternative specimen for COVID-19 diagnosis. comparable performance between dry nasal swabs (NS) and nasopharyngeal swabs (NPS) collected in VTM has been observed ...

ObjectivesWe implemented a diagnostic stewardship care-bundle (DSB): "Sepsis-48" with the aim of evaluating its impact on changes in duration of key steps in automated blood culture diagnostics (aBCD), compliance to care-bundle and turnaround time (TAT). MethodsIn this prospective study, a care-bundle checklist for automated blood culture bottles (BCBs) received from adult intensive care units (AICUs) was implemented between July 2020-June 2021 (intervention period, P2) and compared with a retr...

The existence of the variable component of the systematic error (VCSE) is known since 1963, but seems to be a kind of taboo: neither has definition in VIM, nor is present in equations, being considered transformed in time into random error. Present study using methods of mathematical statistics, computer simulations and examples from the day-to-day practice of the author makes an attempt to reevaluate its role and significance in the QC in clinical laboratory. "The bias" (which one?) it is a de...

Point of care diagnostics for COVID-19 detection are vital to assess infection quickly and at the source so appropriate measures can be taken. The loop-mediated isothermal amplification (LAMP) assay has proven to be a reliable and simple protocol that can detect small amounts of viral RNA in patient samples (<10 genomes per L) (Nagamine, Hase, and Notomi 2002). Recently, Rabe and Cepko at Harvard published a sensitive and simple protocol for COVID-19 RNA detection in saliva using an optimized LA...

Covid-19 crisis showed us that rapid massive virus detection campaign is a key element in SARS-CoV-2 pandemic response. The classical RT-PCR laboratory platforms must be complemented with rapid and simplified technologies to enhance efficiency of large testing strategies. To this aim, we developed EasyCOV, a direct saliva RT-LAMP based SARS-CoV-2 virus detection assay that do not requires any RNA extraction step. It allows robust and rapid response under safe and easy conditions for healthcare ...

BackgroundQuantitative RT-PCR on NasoPharyngeal Swab (NPS) is still considered the standard for the diagnosis of SARS-CoV-2 infection, even if saliva has been evaluated in several studies as a possible alternative. The use of point of care (POC) platforms, providing highly specific results performed on saliva could simplify the diagnosis of COVID-19 and contribute to contain the spreading of SARS-CoV-2. MethodsWe assess the sensitivity and specificity of molecular testing performed on saliva in...

RT-qPCR utilising upper respiratory swabs are the diagnostic gold standard for SARS-CoV-2 despite reported low sensitivity and limited scale up due to global shortages. Saliva is a non-invasive, equipment independent alternative to swabs. We collected 145 paired saliva and nasal/throat (NT) swabs at diagnosis (day 0) and repeated on day 2 and day 7 dependent on inpatient care and day 28 for study follow up. Laboratory cultured virus was used to determine the analytical sensitivity of spiked sal...

The accepted gold standard for diagnosing coronavirus disease (COVID-19) is the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA from nasopharyngeal swabs (NPS). However, shortage of reagents has made NPS collection challenging, and alternative samples need to be explored. Due to its non-invasive nature, saliva has considerable diagnostic potential. Therefore, to guide diagnostic laboratories globally, we conducted a systematic review to determine the utility of sali...

We evaluated the rapid immunochromatographic test for SARS-CoV-2 antigen detection using 16 saliva specimens collected from 6 COVID-19 hospitalized patients, and detected N-antigen in 4 of 7 RT-PCR positive specimens. The POCT antigen test using saliva is highly considered to be a game-changer for COVID-19 diagnosis.

In response to the rapidly evolving COVID-19 pandemic, the U.S. Food and Drug Administration (FDA) has rapidly issued 49 emergency use authorizations (EUAs) for SARS-CoV-2 in vitro diagnostic test-kits. A critical metric in the performance evaluation for a diagnostic test kit is the analytical sensitivity, which is measured by the limit of detection (LOD). Commercial RNA stocks with known titers are used to determine LOD. We identified a problem with the titer reported for the commercial stocks ...

BackgroundThe clinical performance of six molecular diagnostic tests and a rapid antigen test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were clinically evaluated for the diagnosis of coronavirus disease 2019 (COVID-19) in self-collected saliva. MethodsSaliva samples from 103 patients with laboratory-confirmed COVID-19 (15 asymptomatic and 88 symptomatic) were collected on the day of hospital admission. SARS-CoV-2 RNA in saliva was detected using a quantitative reverse-tra...

ObjectivesThe number of COVID-19 cases is increasing globally and there is an urgency for a simple non-invasive method for the detection of SARS-CoV-2. Our study aimed to demonstrate that saliva can be used as a specimen for SARS-CoV-2 detection notably for the screening of extensive population groups via pooling. MethodsTo demonstrate that saliva is an appropriate specimen for SARS-CoV-2 detection a field study including 3,660 participants was performed between September 29 and October 1, 2020...

SARS-CoV-2 infections can be symptomatic as well as asymptomatic. In this study, we analyzed 460,814 saliva samples collected from July 2020 to January 2021 for a SARS-CoV-2-specific gene target using the FDA EUA test, CRL Rapid Response, based on reverse transcription polymerase chain reaction (RT-PCR). We measured SARS-CoV-2 viral loads using cycle threshold (Ct) values. A total of 17,813 samples tested positive for COVID-19 using self-collected saliva samples. The Ct values ranged from 11 to ...

Background: We assessed the performance, stability, and user acceptability of swab-independent self-collected saliva and saline mouth rinse/gargle sample types for the molecular detection of SARS-CoV-2 in adults and school-aged children. Methods: Outpatients who had recently been diagnosed with COVID-19 or were presenting with suspected COVID-19 were asked to have a nasopharyngeal swab collected and provide at least one self-collected sample type. A portion of participants were also asked about ...