Diagnostic performance between CT and initial real-time RT-PCR for clinically suspected 2019 coronavirus disease (COVID-19) patients outside Wuhan, China

Universal laboratory testing for SARS-CoV-2 in hyperacute stroke during the COVID-19 pandemic

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Despite rigorous universal testing in a protected code stroke protocol, none of the consecutive 116 stroke patients tested were positive for SARS-CoV-2.

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Universal testing did not adversely affect hyperacute stroke care.

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Information on SARS-CoV-2 status can be used to guide protective measures in patients with acute stroke.

Objective

Stroke patients are thought to be at increased risk of Coronavirus Disease 2019 (COVID-19). To evaluate yield of universal laboratory testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in acute stroke patients and its impact on hyperacute stroke care.

Methods

Between weeks 14 and 18 in 2020, a protected code stroke protocol including infection control screening and laboratory testing for SARS-CoV-2 was prospectively implemented for all code stroke patients upon arrival to the emergency department. If infection control screen was positive, patients received protective hygienic measures and laboratory test results were available within four hours from testing. In patients with negative screen, laboratory results were available no later than the next working day. Door-to-imaging times of patients treated with thrombolysis or thrombectomy were compared with those of patients treated during the preceding weeks 1 to 13 in 2020.

Results

During the 4-weeks study period, 116 consecutive code stroke patients underwent infection control screen and laboratory testing for SARS-CoV-2. Among 5 (4.3%) patients whose infection control screen was positive, no patient was tested positive for SARS-CoV-2. All patients with negative infection control screens had negative test results. Door-to-imaging times of patients treated with thrombolysis and/or thrombectomy were not different to those treated during the preceding weeks (12 [9-15] min versus 13 [11-17] min, p = 0.24).

Conclusions

Universal laboratory testing for SARS-CoV-2 provided useful information on patients’ infection status and its implementation into a protected code stroke protocol did not adversely affect hyperacute stroke care.

Laboratory diagnosis of SARS-CoV-2 - A review of current methods

At present the whole world is facing pandemic of the Coronavirus disease (COVID-19); caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This disease has rapidly spreads across the world from its origin of Wuhan, China and affected millions people worldwide and make them to remain in their homes. The knowledge of available laboratory methods is essential for early and correct diagnosis of COVID-19 to identify new cases as well as monitoring treatment of confirmed cases. In this review we aim to provide the updated information about selection of specimens and availability of various diagnostic methods and their utility with current findings for the laboratory diagnosis of SARS-CoV-2 infection. This will guide the healthcare professionals and government organizations to make strategy for establishing diagnostic facilities for SARS-CoV-2 infections.

SARS-CoV-2: diagnostic and design conundrums in the context of male factor infertility

The question of whether SARS-CoV-2 (severe acute respiratory syndrome-related coronavirus-2 [SARS-CoV-2], leading to the COVID-19 infection) can be harboured in the testes and/or semen is currently unanswered. It is essential to understand the limitations of both antibody and real-time PCR tests in interpreting SARS-CoV-2 data in relation to analyses of semen and testicular tissue without appropriate controls. This article critically analyses the evidence so far on this, and the possible implications. The limitations of diagnostic tests in both sampling and testing methodologies, their validation and their relevance in interpreting data are also highlighted.

It can be dangerous to take epidemic curves of COVID-19 at face value

During an epidemic with a new virus, we depend on modelling to plan the response: but how good are the data? The aim of our work was to better understand the impact of misclassification errors in identification of true cases of COVID-19 on epidemic curves. Data originated from Alberta, Canada (available on 28 May 2020). There is presently no information of sensitivity (Sn) and specificity (Sp) of laboratory tests used in Canada for the causal agent for COVID-19. Therefore, we examined best attainable performance in other jurisdictions and similar viruses. This suggested perfect Sp and Sn 60-95%. We used these values to re-calculate epidemic curves to visualize the potential bias due to imperfect testing. If the sensitivity improved, the observed and adjusted epidemic curves likely fall within 95% confidence intervals of the observed counts. However, bias in shape and peak of the epidemic curves can be pronounced, if sensitivity either degrades or remains poor in the 60-70% range. These issues are minor early in the epidemic, but hundreds of undiagnosed cases are likely later on. It is therefore hazardous to judge progress of the epidemic based on observed epidemic curves unless quality of testing is better understood.

Development of Point-of-Care Biosensors for COVID-19

Coronavirus disease 2019 (COVID-19) outbreak has become a global pandemic. The deleterious effects of coronavirus have prompted the development of diagnostic tools to manage the spread of disease. While conventional technologies such as quantitative real time polymerase chain reaction (qRT-PCR) have been broadly used to detect COVID-19, they are time-consuming, labor-intensive and are unavailable in remote settings. Point-of-care (POC) biosensors, including chip-based and paper-based biosensors are typically low-cost and user-friendly, which offer tremendous potential for rapid medical diagnosis. This mini review article discusses the recent advances in POC biosensors for COVID-19. First, the development of POC biosensors which are made of polydimethylsiloxane (PDMS), papers, and other flexible materials such as textile, film, and carbon nanosheets are reviewed. The advantages of each biosensors along with the commercially available COVID-19 biosensors are highlighted. Lastly, the existing challenges and future perspectives of developing robust POC biosensors to rapidly identify and manage the spread of COVID-19 are briefly discussed.

Accuracy of Emergency Department Clinical Findings for Diagnosis of Coronavirus Disease 2019

Study objective

We seek to describe the medical history and clinical findings of patients attending the emergency department (ED) with suspected coronavirus disease 2019 (COVID-19) and estimate the diagnostic accuracy of patients’ characteristics for predicting COVID-19.

Methods

We prospectively enrolled all patients tested for severe acute respiratory syndrome coronavirus 2 by reverse-transcriptase polymerase chain reaction in our ED from March 9, 2020, to April 4, 2020. We abstracted medical history, physical examination findings, and the clinical probability of COVID-19 (low, moderate, and high) rated by emergency physicians, depending on their clinical judgment. We assessed diagnostic accuracy of these characteristics for COVID-19 by calculating positive and negative likelihood ratios.

Results

We included 391 patients, of whom 225 had positive test results for severe acute respiratory syndrome coronavirus 2. Reverse-transcriptase polymerase chain reaction result was more likely to be negative when the emergency physician thought that clinical probability was low, and more likely to be positive when he or she thought that it was high. Patient-reported anosmia and the presence of bilateral B lines on lung ultrasonography had the highest positive likelihood ratio for the diagnosis of COVID-19 (7.58, 95% confidence interval [CI] 2.36 to 24.36; and 7.09, 95% CI 2.77 to 18.12, respectively). The absence of a high clinical probability determined by the emergency physician and the absence of bilateral B lines on lung ultrasonography had the lowest negative likelihood ratio for the diagnosis of COVID-19 (0.33, 95% CI 0.25 to 0.43; and 0.26, 95% CI 0.15 to 0.45, respectively).

Conclusion

Anosmia, emergency physician estimate of high clinical probability, and bilateral B lines on lung ultrasonography increased the likelihood of identifying COVID-19 in patients presenting to the ED.