SARS-CoV-2 Variant of Concern B.1.1.7: Diagnostic Sensitivity of Three Antigen-Detecting Rapid Tests

Two recently developed Legionella detection tests, a microbiological-immunological method based on monoclonal antibodies (carried out as a colony-blot assay) and a commercial gene-probe testkit (the EnvironAmp Legionella Kit), are compared with the standard method. The colony-blot assay is faster than the conventional method; the gene-probe test is much faster still and is the most sensitive, but in consequence is at greater risk of false-positive results.

Download Full-text

Limits and Opportunities of SARS-CoV-2 Antigen Rapid Tests: An Experienced-Based Perspective

Pathogens ◽

10.3390/pathogens10010038 ◽

2021 ◽

Vol 10 (1) ◽

pp. 38

Author(s):

Verena Schildgen ◽

Sabrina Demuth ◽

Jessica Lüsebrink ◽

Oliver Schildgen

Keyword(s):

Clinical Setting ◽

Gold Standard ◽

Antigen Test ◽

Public Attention ◽

High Expectations ◽

Test Strategy ◽

Rapid Tests ◽

Pilot Sample ◽

Lateral Flow Tests ◽

Throat Washing

Background: Due to the steadily rising case numbers of SARS-CoV-2 infections worldwide, there is an increasing need for reliable rapid diagnostic devices in addition to existing gold standard PCR methods. Actually, public attention is focused on antigen assays including lateral flow tests (LFTs) as a diagnostic alternative. Therefore, different LFTs were analyzed regarding their performance in a clinical setting. Material and Methods: A pilot sample panel of 13 bronchoalveolar fluids (BALFs) and 60 throat washing (TW) samples with confirmed PCR results, as well as eight throat washes invalid by PCR, were tested with the BIOCREDIT test (RapiGEN), the PanbioTM assay (Abbott), and the SARS-CoV-2 rapid antigen test (Roche). Conclusion: The analyzed antigen test showed an interassay correlation of 27.4%, with overall specificities ranging from 19.4% to 87.1%, while sensitivities of the respective tests ranged between 33.3% and 88.1%. Because these assays did not entirely meet all high expectations, their benefit has to be carefully evaluated for the respective test strategy and setting.

Download Full-text

Aptamer-Based Diagnostic Systems for the Rapid Screening of TB at the Point-of-Care

Diagnostics ◽

10.3390/diagnostics11081352 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1352

Author(s):

Darius Riziki Martin ◽

Nicole Remaliah Sibuyi ◽

Phumuzile Dube ◽

Adewale Oluwaseun Fadaka ◽

Ruben Cloete ◽

...

Keyword(s):

Low Income ◽

Point Of Care ◽

Health Care Systems ◽

Cost Effective ◽

Rapid Screening ◽

Low Income Countries ◽

Sputum Smear ◽

Diagnostic Systems ◽

Molecular Tests ◽

Rapid Tests

The transmission of Tuberculosis (TB) is very rapid and the burden it places on health care systems is felt globally. The effective management and prevention of this disease requires that it is detected early. Current TB diagnostic approaches, such as the culture, sputum smear, skin tuberculin, and molecular tests are time-consuming, and some are unaffordable for low-income countries. Rapid tests for disease biomarker detection are mostly based on immunological assays that use antibodies which are costly to produce, have low sensitivity and stability. Aptamers can replace antibodies in these diagnostic tests for the development of new rapid tests that are more cost effective; more stable at high temperatures and therefore have a better shelf life; do not have batch-to-batch variations, and thus more consistently bind to a specific target with similar or higher specificity and selectivity and are therefore more reliable. Advancements in TB research, in particular the application of proteomics to identify TB specific biomarkers, led to the identification of a number of biomarker proteins, that can be used to develop aptamer-based diagnostic assays able to screen individuals at the point-of-care (POC) more efficiently in resource-limited settings.

Download Full-text

Practical guide to improving diagnostic sensitivity of bile duct brushings

Hepatobiliary & Pancreatic Diseases International ◽

10.1016/j.hbpd.2021.01.001 ◽

2021 ◽

Author(s):

Ioannis C Varbobitis ◽

Jonathan C Booth ◽

Cameron L Griffiths ◽

Nishchay Chandra

Keyword(s):

Bile Duct ◽

Diagnostic Sensitivity ◽

Practical Guide

Download Full-text

The Usefulness of Spectral Mammography in Surgical Planning of Breast Cancer Treatment—Analysis of 999 Patients with Primary Operable Breast Cancer

Current Oncology ◽

10.3390/curroncol28040232 ◽

2021 ◽

Vol 28 (4) ◽

pp. 2548-2559

Author(s):

Andrzej Lorek ◽

Katarzyna Steinhof-Radwańska ◽

Anna Barczyk-Gutkowska ◽

Wojciech Zarębski ◽

Piotr Paleń ◽

...

Keyword(s):

Breast Cancer ◽

Predictive Value ◽

Breast Imaging ◽

Incidence Rates ◽

Diagnostic Sensitivity ◽

Breast Cancer Surgery ◽

Imaging Method ◽

Treatment Change ◽

Contrast Enhanced ◽

General Number

Contrast-enhanced spectral mammography (CESM) is a promising, digital breast imaging method for planning surgeries. The study aimed at comparing digital mammography (MG) with CESM as predictive factors in visualizing multifocal-multicentric cancers (MFMCC) before determining the surgery extent. We analyzed 999 patients after breast cancer surgery to compare MG and CESM in terms of detecting MFMCC. Moreover, these procedures were assessed for their conformity with postoperative histopathology (HP), calculating their sensitivity and specificity. The question was which histopathological types of breast cancer were more frequently characterized by multifocality–multicentrality in comparable techniques as regards the general number of HP-identified cancers. The analysis involved the frequency of post-CESM changes in the extent of planned surgeries. In the present study, MG revealed 48 (4.80%) while CESM 170 (17.02%) MFMCC lesions, subsequently confirmed in HP. MG had MFMCC detecting sensitivity of 38.51%, specificity 99.01%, PPV (positive predictive value) 85.71%, and NPV (negative predictive value) 84.52%. The respective values for CESM were 87.63%, 94.90%, 80.57% and 96.95%. Moreover, no statistically significant differences were found between lobular and NST cancers (27.78% vs. 21.24%) regarding MFMCC. A treatment change was required by 20.00% of the patients from breast-conserving to mastectomy, upon visualizing MFMCC in CESM. In conclusion, mammography offers insufficient diagnostic sensitivity for detecting additional cancer foci. The high diagnostic sensitivity of CESM effectively assesses breast cancer multifocality/multicentrality and significantly changes the extent of planned surgeries. The multifocality/multicentrality concerned carcinoma, lobular and invasive carcinoma of no special type (NST) cancers with similar incidence rates, which requires further confirmation.

Download Full-text

A Tool Derived from the Vicia faba Micronucleus Assay, to Assess Genotoxicity, Cytotoxicity or Biostimulation of Novel Compounds Used in Agriculture

Agronomy ◽

10.3390/agronomy11020321 ◽

2021 ◽

Vol 11 (2) ◽

pp. 321

Author(s):

Perrine Klein ◽

Lorelei Chauvey ◽

Jean Kallerhoff ◽

Eric Pinelli ◽

Marie Morard ◽

...

Keyword(s):

Vicia Faba ◽

Maleic Hydrazide ◽

Lead Nitrate ◽

Micronucleus Assay ◽

Growth Potential ◽

Protective Effects ◽

Genotoxic Effects ◽

Cytotoxic Effects ◽

Conventional Agriculture ◽

Rapid Tests

The increased use of biostimulants in conventional agriculture and organic farming requires the implementation of rapid tests to determine their effectiveness in enhancing plant growth and protection against abiotic stresses. However, their innocuity to plant health has rarely been demonstrated. We used the Vicia faba Micronucleus Assay, as described by the standard AFNOR EN ISO 29200(2020-05) to reveal biostimulant, genotoxic and cytotoxic effects of four commercialized wood-based products by comparing mitotic indices and micronucleus frequencies with respect to the controls. Neither genotoxicity, as measured by micronucleus frequency (MN), nor cytotoxicity, assessed by Mitotic index counts, was observed. Additionally, one of these stimulants (BHS®) conferred protective effects against contaminants (maleic hydrazide or lead nitrate). We describe that plotting micronuclei frequency against mitotic indices allows discrimination between cytotoxic/genotoxic effects from growth levels. Vicia faba experiments were successfully transposed to other agronomical important crops such as corn and sunflower. This technique can be valuable to industrials, to assess growth, potential cytoxicity and genotoxicity effects of any new biostimulant or organic.

Download Full-text

Discriminating the eight genotypes of the porcine circovirus type 2 with TaqMan-based real-time PCR

Virology Journal ◽

10.1186/s12985-021-01541-z ◽

2021 ◽

Vol 18 (1) ◽

Author(s):

Ellen Kathrin Link ◽

Matthias Eddicks ◽

Liangliang Nan ◽

Mathias Ritzmann ◽

Gerd Sutter ◽

...

Keyword(s):

Real Time ◽

Real Time Pcr ◽

Porcine Circovirus Type ◽

Porcine Circovirus Type 2 ◽

Diagnostic Sensitivity ◽

Locked Nucleic Acid ◽

Porcine Circovirus ◽

Amplification Efficiency ◽

Pcr Assays

Abstract Background The porcine circovirus type 2 (PCV2) is divided into eight genotypes including the previously described genotypes PCV2a to PCV2f and the two new genotypes PCV2g and PCV2h. PCV2 genotyping has become an important task in molecular epidemiology and to advance research on the prophylaxis and pathogenesis of PCV2 associated diseases. Standard genotyping of PCV2 is based on the sequencing of the viral genome or at least of the open reading frame 2. Although, the circovirus genome is small, classical sequencing is time consuming, expensive, less sensitive and less compatible with mass testing compared with modern real-time PCR assays. Here we report about a new PCV2 genotyping method using qPCR. Methods Based on the analysis of several hundred PCV2 full genome sequences, we identified PCV2 genotype specific sequences or single-nucleotide polymorphisms. We designed six TaqMan PCR assays that are specific for single genotypes PCV2a to PCV2f and two qPCRs targeting two genotypes simultaneously (PCV2g/PCV2d and PCV2h/PCV2c). To improve specific binding of oligonucleotide primers and TaqMan probes, we used locked nucleic acid technology. We evaluated amplification efficiency, diagnostic sensitivity and tested assay specificity for the respective genotypes. Results All eight PCV2 genotype specific qPCRs demonstrated appropriate amplification efficiencies between 91 and 97%. Testing samples from an epidemiological field study demonstrated a diagnostic sensitivity of the respective genotype specific qPCR that was comparable to a highly sensitive pan-PCV2 qPCR system. Genotype specificity of most qPCRs was excellent. Limited unspecific signals were obtained when a high viral load of PCV2b was tested with qPCRs targeting PCV2d or PCV2g. The same was true for the PCV2a specific qPCR when high copy numbers of PCV2d were tested. The qPCR targeting PCV2h/PCV2c showed some minor cross-reaction with PCV2d, PCV2f and PCV2g. Conclusion Genotyping of PCV2 is important for routine diagnosis as well as for epidemiological studies. The introduced genotyping qPCR system is ideal for mass testing and should be a valuable complement to PCV2 sequencing, especially in the case of simultaneous infections with multiple PCV2 genotypes, subclinically infected animals or research studies that require large sample numbers.

Download Full-text

Steps towards implementing evidence-based screening in family medicine in Ukraine: SWOT-analysis of an approach of multidimensional empowerment

BMC Family Practice ◽

10.1186/s12875-021-01367-2 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Pavlo Kolesnyk ◽

Thomas Frese ◽

Shlomo Vinker ◽

Ivanna Shushman ◽

Albina Zharkova ◽

...

Keyword(s):

Swot Analysis ◽

Screening Program ◽

Implementation Process ◽

Evidence Based ◽

National Guidelines ◽

Family Doctors ◽

External Threats ◽

The Family ◽

Gate Keeping ◽

Rapid Tests

Abstract Background The purpose of this study is to forward the implementation of an operational evidence-based state screening program of common diseases in Ukraine, where currently no state-based and evidence-based screening (EBS) exists. EBS should be performed by Family Doctors in a primary care setting and concern prevalent diseases in adults, such as: obesity (BMI), hypertension (BP measurement), diabetes (glycaemia), dyslipidemia (cholesterol/lipids), colon cancer (FOBT/colonoscopy), breast cancer (mammography), STIs (chlamydia, syphilis), HIV, HBV, HCV (i.e. serology or other rapid tests), HPV (swabs), cervical cancer (test Pap). depression (i.e., PHQ-9), and smoking (i.e., Fagerstrom). Methods Four needs-based research actions were led among citizens and healthcare professionals, based on multidimensional empowerment. Internal Strengths and Weaknesses of the ongoing implementation process were identified through these studies, whereas external Opportunities and Threats were determined by the present socio-cultural and political context. This SWOT analysis is likely to guide future state-based initiatives to accomplish EBS implementation in Ukraine. Results Internal Strengths are the bottom-up multidimensional empowerment approach, teaching of EBS and the development of an internet-based platform “Screening adviser” to assist shared decision making for person-centred EBS programs. Internal Weaknesses identified for the Family Doctors are a heterogeneous screening and the risk of decreasing motivation to screen. External Opportunities include the ongoing PHC reform, the existent WONCA and WHO support, and the existence of EBS programs in Europe. External Threats are the lack of national guidelines, not fully introduced gate keeping system, the vulnerable socio-economic situation, the war situation in the East of Ukraine and the Covid-19 pandemic. Conclusions We started EBS implementation through research actions, based on a multidimensional empowerment of citizens, HCP and in EBS pathways involved stakeholder teams, to foster a sustainable operational human resource to get involved in that new EBS pathway to implement. The presented SWOT-analysis of this ongoing implementation process allows to plan and optimize future steps towards a state based and supports EBS program in Ukraine.

Download Full-text

Performance of a SARS CoV-2 antibody ELISA based on simultaneous measurement of antibodies against the viral nucleoprotein and receptor-binding domain

European Journal of Clinical Microbiology & Infectious Diseases ◽

10.1007/s10096-021-04284-5 ◽

2021 ◽

Author(s):

Nina Reiners ◽

Carolin Schnurra ◽

Henning Trawinski ◽

Judith Kannenberg ◽

Thomas Hermsdorf ◽

...

Keyword(s):

Receptor Binding ◽

Simultaneous Measurement ◽

False Positives ◽

Binding Domain ◽

Diagnostic Sensitivity ◽

Spike Protein ◽

Receptor Binding Domain ◽

Simultaneous Testing ◽

Antibody Assays ◽

Antibody Elisa

AbstractSARS CoV-2 antibody assays measure antibodies against the viral nucleoprotein (NP) or spike protein. The study examined if testing of antibodies against both antigens increases the diagnostic sensitivity. Sera (N=98) from infected individuals were tested with ELISAs based on the NP, receptor-binding domain (RBD), or both proteins. The AUROCs were 0.958 (NP), 0.991 (RBD), and 0.992 (NP/RBD). The RBD- and NP/RBD-based ELISAs showed better performance than the NP-based assay. Simultaneous testing for antibodies against NP and RBD increased the number of true and false positives. If maximum diagnostic sensitivity is required, the NP/RBD-based ELISA is preferable. Otherwise, the RBD-based ELISA is sufficient.

Download Full-text

Clinical significance of small molecule metabolites in the blood of patients with different types of liver injury

Scientific Reports ◽

10.1038/s41598-021-91164-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Hui Li ◽

Yan Wang ◽

Shizhao Ma ◽

Chaoqun Zhang ◽

Hua Liu ◽

...

Keyword(s):

Oleic Acid ◽

Clinical Diagnosis ◽

Sensitivity And Specificity ◽

Acid Amide ◽

Hbv Infection ◽

Diagnostic Sensitivity ◽

Future Research ◽

Diagnostic Efficacy ◽

Metabolic Markers ◽

Diagnostic Sensitivity And Specificity

AbstractTo understand the characteristic of changes of serum metabolites between healthy people and patients with hepatitis B virus (HBV) infection at different stages of disease, and to provide reference metabolomics information for clinical diagnosis of liver disease patients. 255 patients with different stages of HBV infection were selected. 3 mL blood was collected from each patient in the morning to detect differences in serum lysophosphatidylcholine, acetyl-l-carnitine, oleic acid amide, and glycocholic acid concentrations by UFLC-IT-TOF/MS. The diagnostic values of four metabolic substances were evaluated by receiver operating characteristic (ROC) curve. The results showed that the optimal cut-off value of oleic acid amide concentration of the liver cirrhosis and HCC groups was 23.6 mg/L, with a diagnostic sensitivity of 88.9% and specificity of 70.6%. The diagnostic efficacies of the three substances were similar in the hepatitis and HCC groups, with an optimal cut-off value of 2.04 mg/L, and a diagnostic sensitivity and specificity of 100% and 47.2%, respectively. The optimal cut-off value of lecithin of the HBV-carrier and HCC groups was 132.85 mg/L, with a diagnostic sensitivity and specificity of 88.9% and 66.7%, respectively. The optimal cut-off value of oleic acid amide of the healthy and HCC groups was 129.03 mg/L, with a diagnostic sensitivity and specificity of 88.4% and 83.3%, respectively. Lysophosphatidylcholine, acetyl-l-carnitine, and oleic acid amide were potential metabolic markers of HCC. Among them, lysophosphatidylcholine was low in the blood of HCC patients, and its diagnostic efficacy was better than that of acetyl-l-carnitine and oleic acid amide, providing reference metabolomics information in clinical diagnosis and future research.

Download Full-text