Laboratory diagnosis of Ebola virus disease plays a critical role in outbreak response efforts; however, establishing safe and expeditious testing strategies for this high-biosafety-level pathogen in ...resource-poor environments remains extremely challenging. Since the discovery of Ebola virus in 1976 via traditional viral culture techniques and electron microscopy, diagnostic methodologies have trended toward faster, more accurate molecular assays. Importantly, technological advances have been paired with increasing efforts to support decentralized diagnostic testing capacity that can be deployed at or near the point of patient care. The unprecedented scope of the 2014-2015 West Africa Ebola epidemic spurred tremendous innovation in this arena, and a variety of new diagnostic platforms that have the potential both to immediately improve ongoing surveillance efforts in West Africa and to transform future outbreak responses have reached the field. In this review, we describe the evolution of Ebola virus disease diagnostic testing and efforts to deploy field diagnostic laboratories in prior outbreaks. We then explore the diagnostic challenges pervading the 2014-2015 epidemic and provide a comprehensive examination of novel diagnostic tests that are likely to address some of these challenges moving forward.
The number and complexity of clinical laboratory tests is rapidly expanding, presenting primary care physicians with challenges in accurately, efficiently, and safely ordering and interpreting ...diagnostic tests. The objective of this study was to identify challenges primary care physicians face related to diagnostic laboratory testing and solutions they believe are helpful and available to them.
In this study, sponsored by the Centers for Disease Control and Prevention, a random sample of general internal medicine and family medicine physicians from the American Medical Association Masterfile were surveyed in 2011.
1768 physicians (5.6%) responded to the survey. Physicians reported ordering diagnostic laboratory tests for an average of 31.4% of patient encounters per week. They reported uncertainty about ordering tests in 14.7% and uncertainty in interpreting results in 8.3% of these diagnostic encounters. The most common problematic challenges in ordering tests were related to the cost to patients and insurance coverage restrictions. Other challenges included different names for the same test, tests not available except as part of a test panel, and different tests included in panels with the same names. The most common problematic challenges in interpreting and using test results were not receiving the results and confusing report formats. Respondents endorsed a variety of information technology and decision support solutions to improve test selection and results interpretation, but these solutions were not widely available at the time of the survey. Physicians infrequently sought assistance or consultation from laboratory professionals but valued these consultations when they occurred.
Primary care physicians routinely experience uncertainty and challenges in ordering and interpreting diagnostic laboratory tests. With more than 500 million primary care patient visits per year, the level of uncertainty reported in this study potentially affects 23 million patients per year and raises significant concerns about the safe and efficient use of laboratory testing resources. Improvement in information technology and clinical decision support systems and quick access to laboratory consultations may reduce physicians' uncertainty and mitigate these challenges.
The ability to detect SARS-CoV-2 in the upper respiratory tract ceases after 2 to 3 weeks post-symptom-onset in most patients. In contrast, SARS-CoV-2 can be detected in the stool of some patients ...for greater than 4 weeks, suggesting that stool may hold utility as an additional source for diagnosis. We validated the Cepheid Xpert Xpress SARS-CoV-2 and Hologic Panther Fusion real-time RT-PCR assays for detection of viral RNA in stool specimens and compared performance. We utilized remnant stool specimens (
= 79) from 77 patients with gastrointestinal symptoms. Forty-eight patients had PCR-confirmed COVID-19, and 29 either were nasopharyngeal/oropharyngeal PCR negative or presented for reasons unrelated to COVID-19 and were not tested. Positive percent agreement between the Cepheid and Hologic assays was 93% (95% confidence interval CI: 81.1% to 98.2%), and negative percent agreement was 96% (95% CI: 89% to 0.99%). Four discrepant specimens (Cepheid positive only,
= 2; Hologic positive only,
= 2) exhibited average cycle threshold (
) values of >37 for the targets detected. Of the 48 patients with PCR-confirmed COVID-19, 23 were positive by both assays (47.9%). For the negative patient group, 2/29 were positive by both assays (6.9%). The two stool PCR-positive, nasopharyngeal/oropharyngeal PCR-negative patients were SARS-CoV-2 IgG positive. Our results demonstrate acceptable agreement between two commercially available molecular assays and support the use of stool PCR to confirm diagnosis when SARS-CoV-2 is undetectable in the upper respiratory tract.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), a newly emerging human infectious disease. Because no specific antiviral drugs or vaccines are ...available to treat COVID-19, early diagnostics, isolation, and prevention are crucial for containing the outbreak. Molecular diagnostics using reverse transcription polymerase chain reaction (RT-PCR) are the current gold standard for detection. However, viral RNAs are much less stable during transport and storage than proteins such as antigens and antibodies. Consequently, false-negative RT-PCR results can occur due to inadequate collection of clinical specimens or poor handling of a specimen during testing. Although antigen immunoassays are stable diagnostics for detection of past infection, infection progress, and transmission dynamics, no matched antibody pair for immunoassay of SARS-CoV-2 antigens has yet been reported. In this study, we designed and developed a novel rapid detection method for SARS-CoV-2 spike 1 (S1) protein using the SARS-CoV-2 receptor ACE2, which can form matched pairs with commercially available antibodies. ACE2 and S1-mAb were paired with each other for capture and detection in a lateral flow immunoassay (LFIA) that did not cross-react with SARS-CoV Spike 1 or MERS-CoV Spike 1 protein. The SARS-CoV-2 S1 (<5 ng of recombinant proteins/reaction) was detected by the ACE2-based LFIA. The limit of detection of our ACE2-LFIA was 1.86 × 105 copies/mL in the clinical specimen of COVID-19 Patients without no cross-reactivity for nasal swabs from healthy subjects. This is the first study to detect SARS-CoV-2 S1 antigen using an LFIA with matched pair consisting of ACE2 and antibody. Our findings will be helpful to detect the S1 antigen of SARS-CoV-2 from COVID-19 patients.
•The human ACE2 and commercial antibody were paired with each other as capture and detection probes in a lateral flow immunoassay that was not cross-reactive with SARS-CoV S1 and MERS-CoV S1 proteins.•The limit of detection of our ACE2-LFIA was 1.86 × 105 copies/mL in the clinical specimen of COVID-19 patients without no cross-reactivity for nasal swabs from healthy subjects.•This is the first study to detect SARS-CoV-2 S1 antigen using an LFIA with matched pair consisting of ACE2 and antibody.
PCR has become one of the most valuable techniques currently used in bioscience, diagnostics and forensic science. Here we review the history of PCR development and the technologies that have evolved ...from the original PCR method. Currently, there are two main areas of PCR utilization in bioscience: high-throughput PCR systems and microfluidics-based PCR devices for point-of-care (POC) applications. We also discuss the commercialization of these techniques and conclude with a look into their modifications and use in innovative areas of biomedicine. For example, real-time reverse transcription PCR is the gold standard for SARS-CoV-2 diagnoses. It could also be used for POC applications, being a key component of the sample-to-answer system.
•The values of laboratory indicators in 35 articles were integrated.•The laboratory indexes of severe and non-severe patients infected with COVID-19 has been compared.•Indicators that may most ...effectively predict a non-severe COVID-19 patient develop into a severe patient have been concluded.
The pandemic coronavirus disease 2019 (COVID-19) has threaten the global health. The characteristics of laboratory findings of coronavirus are of great significance for clinical diagnosis and treatment. We found indicators that may most effectively predict a non-severe COVID-19 patient develop into a severe patient.
We conducted a meta-analysis to compare the laboratory findings of severe patients with non-severe patients with COVID-19 from searched articles.
Through the analysis of laboratory examination information of patients with COVID-19 from 35 articles (5912 patients), we demonstrated that severe cases possessed higher levels of leukocyte (1.20-fold), neutrophil (1.33-fold), CRP (3.04-fold), PCT (2.00-fold), ESR (1.44-fold), AST (1.40-fold), ALT (1.34-fold), LDH (1.54-fold), CK (1.44-fold), CK-MB (1.39-fold), total bilirubin (1.14-fold), urea (1.28-fold), creatine (1.09-fold), PT (1.03-fold) and D-dimer (2.74-fold), as well as lower levels of lymphocytes (1.44-fold), eosinophil (2.00-fold), monocyte (1.08-fold), Hemoglobin (1.53-fold), PLT (1.15-fold), albumin (1.15-fold), and APTT (1.02-fold). Lymphocyte subsets and series of inflammatory cytokines were also different in severe cases with the non-severe ones, including lower levels of CD4 T cells (2.10-fold) and CD8 T cells (2.00-fold), higher levels of IL-1β (1.02-fold), IL-6 (1.93-fold) and IL-10 (1.55-fold).
Some certain laboratory inspections could predict the progress of the COVID-19 changes, especially lymphocytes, CRP, PCT, ALT, AST, LDH, D-dimer, CD4 T cells and IL6, which provide valuable signals for preventing the deterioration of the disease.
Introduction
The recent appearance of SARS-CoV-2 in Wuhan in 2019 has started a pandemic which has involved over a million people worldwide. A matter of debate is the possible viral detection in ...different body fluids than respiratory droplets. Thus, we evaluated the possible presence of SARS-CoV-2 in semen and urine samples of a volunteer with confirmed COVID-19.
Materials and methods
A 31-year-old man with fever, myalgia, anosmia, and ageusia was tested and found positive for SARS-CoV-2 through a pharyngeal swab. Eight days after he provided semen and urine samples in which viral RNA presence was measured using a Real time RT PCR system (RealStar SARS-CoV-2 RT-PCR, Altona Diagnostics) targeting E and S viral genes.
Results and discussion
Semen and urine samples search for SARS-CoV-2 RNA was negative. Although this should be interpreted cautiously, it may be possible that either the viral clearance kinetics in these matrices matches the progressive clinical recovery of the patient or that the virus was never present in these fluids at the time of the laboratory diagnosis.
The novel coronavirus SARS-CoV-2 is the causative agent of the acute respiratory disease COVID-19, which has become a global concern due to its rapid spread. Meanwhile, increased demand for testing ...has led to a shortage of reagents and supplies and compromised the performance of diagnostic laboratories in many countries. Both the World Health Organization (WHO) and the Center for Disease Control and Prevention (CDC) recommend multi-step RT-PCR assays using multiple primer and probe pairs, which might complicate the interpretation of the test results, especially for borderline cases. In this study, we describe an alternative RT-PCR approach for the detection of SARS-CoV-2 RNA that can be used for the probe-based detection of clinical isolates in diagnostics as well as in research labs using a low-cost SYBR green method. For the evaluation, we used samples from patients with confirmed SARS-CoV-2 infections and performed RT-PCR assays along with successive dilutions of RNA standards to determine the limit of detection. We identified an M-gene binding primer and probe pair highly suitable for the quantitative detection of SARS-CoV-2 RNA for diagnostic and research purposes.
•COVID19 patients can develop severe acute respiratory distress syndrome (ARDS).•ARDS is a fatal complication and the most common cause of death in COVID19 patients.•Early detection of acute ...respiratory failure is mandatory to promplty identify critically ill COVID19 patients.•Elevated LDH and CRP serum concentrations are associated to respiratory failure in CoVID-19 patients.
The dramatic worldwide CoVID-19 infection requires the identification of a reliable and inexpensive tool to quickly discriminate patients with a more unfavorable outcome.
We performed routine laboratory tests suitable to identify tissue damage and inflammatory status in 123 consecutive CoVID-19 patients admitted to the Emergency Department of the hospital of Piacenza (Emilia-Romagna, Northern Italy). The results were correlated with patients’ respiratory function evaluated by the partial pressure of arterial oxygen to fraction of inspired oxygen ratio (PaO2/FiO2).
The most common laboratory abnormalities were lymphocytopenia and elevated values of C-reactive protein (CRP) and lactate dehydrogenase (LDH). Aspartate aminotransferase (AST), alanine aminotransferase (ALT) and creatine kinase (CK) were also increased. The respiratory performance (PaO2/FiO2) showed a strong inverse correlation with LDH (r = 0.62, r2 0.38, p value < 0.0001) and CRP (r = 0.55, r2 0.31, p value < 0.0001). PaO2/FiO2 values also showed a significant inverse correlation with age (r = −0.37, p < 0.0001), AST (r = −0.31, p < 0.01), WBC (r = −0.49, p < 0.0001), neutrophils count (r = −0.5, p < 0.001). ROC curves showed a sensitivity of 75% and specificity of 70% for the LDH cut-off value of 450 U/L and a sensitivity of 72% and specificity of 71% for the CRP cut-off value of 11 mg/dl in identifying CoVID-19 with moderate-severe ARDS.
LDH and CRP may be related to respiratory function (PaO2/FiO2) and be a predictor of respiratory failure in CoVID-19 patients. LDH and CRP should be considered a useful test for the early identification of patients who require closer respiratory monitoring and more aggressive supportive therapies to avoid poor prognosis.
PDF
