ID: 212302 Prevalence of False Negative Results for Morphine in Oral Fluid Toxicology Compared With Urine Toxicology

Introduction: Urine drug testing has been the standard for monitoring opioid compliance in chronic pain patients. The COVID-19 pandemic created a dilemma for opioid monitoring by severely limiting in-person testing due to safety concerns. Oral fluid toxicology emerged as a feasible, alternative test due to its ability for remote sample collection under virtual supervision while minimizing infringements on patient privacy. However, the efficacy of these two tests for reliably detecting opioids should be explored prior to transitioning to testing only with oral fluids. Method(s): In this study, we compared morphine levels in oral fluid and urine toxicology studies from 5 randomly selected patients from a Chronic Pain Center who were regularly taking high doses (>=90 mEq) of extended-release morphine. Charts from the start of the COVID-19 pandemic until July 2022 were reviewed for urine and oral fluid testing results and medication regimens. All oral fluid and urine test results and collection methods were validated by a nationally recognized toxicology lab. Prescription Monitoring Program (PMP) reports were reviewed for each patient to observe pre-testing prescription trends. Result(s): We found that the overwhelming majority of patients had at least 1 false negative oral fluid test result. The remainder of the oral fluid results were below threshold (10 ng/mL) or ranged from 11.3 to 54 ng/mL of morphine. 80% of patients (n = 5) had at least one negative or positive-but-below-threshold (10 ng/mL) result in their oral fluid sample analyses. In contrast, none of the urine studies had negative results. Urine studies for all patients were positive for morphine and well-above primary cutoff values (100 ng/mL) with levels >6000 ng/mL. PMP reports did not reveal any aberrant drug taking behavior in any of the patients. No unprescribed medications or illicit substances were detected in any of the oral or urine samples. Conclusion(s): The prevalence of false negative results for the detection of morphine metabolites in oral fluid toxicology may be higher than clinicians are currently aware of. Physicians and other providers monitoring opioid compliance in chronic pain patients should keep this possibility in mind when selecting toxicology tests and making conclusions about aberrant drug-taking behavior. Larger scale studies are needed to compare oral fluid and urine levels of morphine with extension to other commonly prescribed opioids. Disclosure: Evan Chung, MD: None, Joseph Valenza, MD: NoneCopyright © 2023

What to Do if the qPCR Test for SARS-CoV-2 or Other Pathogen Lacks Endogenous Internal Control? A Simple Test on Housekeeping Genes.

Some of the products for the molecular diagnosis of infections do not have an endogenous internal control, and this is necessary to ensure that the result is not a false negative. The aim of the project was to design a simple low-cost RT-qPCR test that can confirm the expression of basic metabolism proteins, thus confirming the quality of genetic material for molecular diagnostic tests. Two successful equivalent qPCR assays for the detection of the GADPH and ACTB genes were obtained. The course of standard curves is logarithmic, with a very high correlation coefficient R2 within the range of 0.9955-0.9956. The reaction yield was between 85.5 and 109.7%, and the detection limit (LOD) with 95% positive probability was estimated at 0.0057 ng/µL for GAPDH and 0.0036 ng/µL for ACTB. These tests are universal because they function on various types of samples (swabs, cytology, etc.) and can complement the diagnosis of SARS-CoV-2 and other pathogens, as well as potentially oncological diagnostics.

Production of Sars-Cov-2 Membrane Protein as Better Target Protein for Diagnostic Application

Intro: The COVID-19 pandemic is caused by the SARS-CoV-2 virus, an enveloped RNA of the coronavirus family. The advancement in molecular technology and biochemistry has accelerated the development of diagnostic reagents and assays. Much attention has been focused on the S protein, but the high mutation rate in this region could lead to false negative results. Thus, a better target protein for diagnostic application is needed for accurate detection. Method(s): Nucleotide sequences encoded for membrane (M) glycoprotein gene region of SARS-CoV-2 from Malaysian isolates were extracted from GISAID, aligned, and selected accordingly. The DNA plasmid was commercially synthesized with codon optimization for Escherichia coli (E. coli), and the presence of the M gene was confirmed by PCR. The plasmid was then transformed into E. coli. Later, the expression of M glycoprotein was induced, separated on an SDS-PAGE gel, and transferred onto a nitrocellulose membrane, followed by immunostaining. Finding(s): The analysis of the M glycoprotein against the Omicron strains demonstrated that the amino acid is conserved (99.5%). The M glycoprotein was successfully expressed and detected with antibodies from SARS-CoV-2 infected patients at ~26 kDa. The protein is currently upscale for the generation of monoclonal Ab (Mab). Discussion(s): The M protein of SARS-CoV-2 is more conserved among the virus and also has been reported to confer antigenic properties. Selection of M protein perhaps a better option compared to current detection assays that use spike (S) protein, which could lead to false negative results, as this gene region particularly the ribosome-binding domain (RBD) rapidly undergoes mutations. The utilization of M protein potentially improves negative predictive value (NPV) of the diagnostic test. Conclusion(s): Further development of diagnostic reagents is needed to improve the assay's specificity. The newly developed M protein and the MAb can be used to generate a more accurate viral detection assay.Copyright © 2023

Federated Learning for Healthcare Domain - Pipeline, Applications and Challenges

Federated learning is the process of developing machine learning models over datasets distributed across data centers such as hospitals, clinical research labs, and mobile devices while preventing data leakage. This survey examines previous research and studies on federated learning in the healthcare sector across a range of use cases and applications. Our survey shows what challenges, methods, and applications a practitioner should be aware of in the topic of federated learning. This paper aims to lay out existing research and list the possibilities of federated learning for healthcare industries.© 2022 Copyright held by the owner/author(s).

Efficacy of home respiratory culture kits in people with cystic fibrosis

Background: Respiratory cultures are an important part of clinical care for people with cystic fibrosis (CF). Telemedicine visits during the COVID-19 pandemic have not allowed for routine collection. To address this, the University of Michigan Adult Cystic Fibrosis Program mailed home culture kits to patients. We hypothesized that results from home sputum samples would be consistent with prior cultures obtained in sputum collected in clinic but that self-collected throat swabs would provide false-negative results. We also sought to determine percentage return rate. Method(s): Adults with CF were sent culture kits containing a specimen cup and a throat swab. Patients had the choice to submit either sample for processing. Medical personnel provided written instructions with the culture kits and, on occasion, instructed patients on proper collection techniques via phone. Samples were then refrigerated for up to 24 hours before a delivery service returned the specimen to a University of Michigan laboratory for analysis. Data collected from December 2020 to December 2021 (N = 77) included percentage return rate, result, source, and presence of microorganisms. Pairwise culture data of samples collected in clinic versus home-collected samples within 1 yearwere included in the analysis. Descriptive statistics and Cohen kappa correlation coefficients were computed for all culture data and subgroups (Table 1A-E). Result(s): Of 77 culture kits returned, 46 had corresponding clinic samples collected using the same method, and the remaining 21 were collected using different methods (throat swab vs sputum sample). Overall, approximately 200 kits were mailed to patients, with a return rate of 38.5%. A similar percentage of positive culture results was obtained with same method of collection: sputum and throat samples (Table 1C, D, E), although the discordance rate between cultures collected in clinic and at home ranged from approximately 10% to 30%. Correlation between clinic and home culture data was generally good throughout, except for clinic Table 1 ( 115): Analysis of respiratory culture results for (A) all cultures, (B) different collection, and (C, D, E) same collection method. *p < 0.05. Cohen kappa correlation coefficient between groups: poor agreement <0.20;fair agreement = 0.21-0.40;moderate agreement = 0.41-0.60;good agreement = 0.61-0.80;very good agreement = 0.81-1.00. PsA = Pseudomonas aeruginosa;Staph = Staphylococcus aureus.(Table Presented)versus home throat swabs, probably because of a lowevent rate in the small sample size. Conclusion(s): The data suggest that, overall, clinic and home culture kits provide similar positive results, although discordance in specific culture results was common. This may be due to natural fluctuations from culture to culture in people with CF. A limitation of this study is that the cultures being compared in our study were not completed on the same day. Nevertheless, our data also indicate that collection technique may influence results for certain microorganisms. How these differences might influence antibiotic selection and treatment outcomes in the era of telemedicine requires more investigation. The return rate was found to be relatively low, demonstrating the need for interventions to improve patient outreach and compliance.Copyright © 2022, European Cystic Fibrosis Society. All rights reserved

Sensitivity of RT-PCR tests for SARS-CoV-2 through time.

Reverse transcriptase polymerase chain reaction (RT-PCR) tests are the gold standard for detecting recent infection with SARS-CoV-2. RT-PCR sensitivity varies over the course of an individual's infection, related to changes in viral load. Differences in testing methods, and individual-level variables such as age, may also affect sensitivity. Using data from New Zealand, we estimate the time-varying sensitivity of SARS-CoV-2 RT-PCR under varying temporal, biological and demographic factors. Sensitivity peaks 4-5 days post-infection at 92.7% [91.4%, 94.0%] and remains over 88% between 5 and 14 days post-infection. After the peak, sensitivity declined more rapidly in vaccinated cases compared to unvaccinated, females compared to males, those aged under 40 compared to over 40 s, and Pacific peoples compared to other ethnicities. RT-PCR remains a sensitive technique and has been an effective tool in New Zealand's border and post-border measures to control COVID-19. Our results inform model parameters and decisions concerning routine testing frequency.

Pseudo-V1 ECG lead recording with quality smartwatches and medical interpretation may be necessary for timely and accurate remote detection of atrial flutter/fibrillation

Background: Remote rhythm monitoring with wearable devices is increasingly used especially for early detection of atrial fibrillation/flutter (AF/Afl), being the access to hospital discouraged, especially for frail elderly patients, due to the burden and risk of COVID-19 pandemic. Whereas devices using photo plethysmography (PPG) may misinterpret as AF pulse irregularities due to extrasystoles, patient-directed recording of a single (usually wrist-to-wrist) lead ECG (LEAD I) with hand-held devices or smartwatches have been developed to increase accuracy in AF detection. However, although recent studies validating such devices single-lead ECG recording have shown high sensitivity and specificity, false negative findings such as those reported here are still possible and must be prevented [1]. Purpose(s): Given previous experience of diagnostic uncertainty or failure of the smartwatch ECG (SW-ECG) LEAD I to detect AF/Afl, we have tested if false negative diagnosis could be avoided by recording in addition at least one right precordial (pseudo-V1) lead analyzed by a trained healthcare professional. Method(s): Over one calendar year observation, five patients with previous history of ablated supraventricular arrhythmias suffering sudden palpitations suspected of paroxysmal AF/Afl were instructed to record with their smartwatch at least one precordial lead in addition to LEAD I, to monitor ECG until the termination of symptoms. The SW-ECG strips were sent by telephone for professional interpretation. Diagnostic accuracy based on LEAD I and pseudo-V1 were independently validated by two cardiologists (diagnostic goldstandard - DGS). Result(s): 22 AF/Afl events occurred. Pharmacological cardioversion to sinus rhythm (SR) was obtained in 64%. 192 ECG strips were transmitted. 43,7% of the strips were automatically classified as not significant (or not valid ). Compared to DGS, out of 108 valid strips, correct automatic identification of AF/Afl was obtained in 36,4% with LEAD I, in 33,3% with pseudo V1 and in 54,5% with combined leads, respectively. Interestingly, the SW algorithm has wrongly diagnosed as SR, not only LEAD I, but also 39,4% of pseudo-V1 strips, despite clear-cut evidence of typical flutter waves (Figure 1), when RR intervals were regular due to high degree (e.g., 4:1) A-V block. Conclusion(s): With simple instructions, patients (or their relatives) can easily record an additional precordial (pseudo-V1) SW-ECG lead, that may enhance sensitivity and specificity for remote detection of AF/Afl. However, at present, visual interpretation of SW-ECG by a trained healthcare professional is still needed to guarantee 100% correct diagnosis of AF/Afl, crucial to reduce thromboembolic risk and timely initiate the appropriate treatments. The automatic interpretation of SW's ECG could be improved by appropriate training of a machine learning approach to detect and analyze the atrial waveform provided by an additional pseudo-V1 lead.

A retrospective study to evaluate CTPA outcomes in COVID-19 patients at a district hospital in London

Background: COVID-19 is associated with the development of life-threatening prothrombotic events, including pulmonary emboli (PE), for which the gold standard investigation is a CTPA. Aim(s): To assess the incidence of PE in our local high-dependency and ward-based COVID-19 ward and identify common indications for CTPA. Method(s): Data was collected retrospectively from inpatients admitted to our COVID-19 ward between August 1st to October 31st, 2021. Patient demographics, D-dimer values, oxygen requirements, and CTPA request indications and findings were analysed. Result(s): From a total of N=123 patients, N=45 (36.9%) had a CTPA, and N=4 (3.3% of all patients, 8.9% of CTPA requests) were positive for PE. N=44 (97.8%) CTPAs were requested to rule out a PE, with the main indications being a raised D-dimer (26.7%), hypotension (24.4%), persistent oxygen requirement (22.2%), and desaturation (22.2%). N=18 (40%) required non-invasive ventilation (NIV) at the time of CTPA request. The median time spent on therapeutic anticoagulation before a CTPA was 6 days (IQR 9). N=8 (17.7%) had bleeding complications from therapeutic anticoagulation. Conclusion(s): Our 3.3% incidence of PE is lower than the 11.7% average in a recent meta-analysis of ITU patients, consistent with studies showing that those with more severe COVID-19 have a higher incidence of PE (Tan, B.K. et al. Thorax 2021;76: 970-979). Our study was limited, as our patients could not have a CTPA whilst on NIV. They remained on therapeutic anticoagulation during this time, leading to potential false-negative results. Further studies are needed to estimate the incidence of PE and optimum duration of thromboprophylaxis in non-severe COVID-19 cases.

Principles of management for patients with oral cancer during the COVID-19 pandemic

The outbreak of coronavirus disease 2019 (COVID-19) affects the world. It is highly contagious and spreads quickly. COVID-19 severely increases the medical burden and interferes with our normal work. This article introduces our experience on treat oral cancer patients during the epidemic. The negative impact can be minimized through reasonable and orderly arrangement.Copyright © 2021 The Authors

Problems of PCR diagnostics OF COVID-19.

To date, an adequate and timely assessment of the number of cases is the basis of effective measures aimed at preventing the spread of COVID-19 infection. Real-time reverse transcription polymerase chain reaction (RT-PCR) remains the gold standard for confirming COVID-19. The purpose of the work: to analyze the experience of the city virological center of the S.P. Botkin Clinical Infectious Diseases Hospital (Botkin Hospital) for the examination for the presence of SARS-CoV-2 coronavirus by PCR in the period from 2020 to 2022. Materials and methods. The systematization of PCR studies on COVID-19 for the period 2020-2022 was carried out. A total of 221,901 people were examined, positive results were obtained in 55,372 (24.95%). Among the contingents of the examined patients, patients who underwent inpatient treatment at the Botkin Hospital, Conclusions. This study analyzed the possible causes of false-positive and false-negative PCR results. The correlation of the number of positive results with the dynamics of detection of new cases of COVID-19 in St. Petersburg during the 2020-2022 pandemic is shown. It has been established that the proportion of patients examined more than 3 times during the period of hospitalization remains significant. This fact requires the closest attention, given the high cost and laboriousness of PCR studies.Copyright © 2022 Authors. All rights reserved.

Rational Use of COVID-19 Virological Tests in Intensive Care Unit

The ongoing COVID-19 pandemic reminded once again that microbiological diagnostic methods are irreplaceable in both diagnosing and detecting asymptomatic persons. At present, real-time reverse transcriptase polymerase chain reaction (RT-PCR) is the gold standard method for diagnosing COVID-19, but the test's accuracy varies in sample quality. Especially in the last stages of the disease, negative results of nasopharyngeal or oropharyngeal swab samples or rapid antigen tests do not necessarily mean that these patients do not carry the virus. Considering that a significant number of COVID-19 patients need intensive care and mechanical ventilation in the late period, which sample should be taken from where and when should be evaluated. Lower respiratory tract samples have a more significant chance of finding viral RNA than upper respiratory tract samples. Technical recommendations and the virological diagnostic methodologies and used in the intensive care unit of patients infected with SARS-CoV-2 are summarized in this article. We aimed to emphasize the need to get a sample from the right place at the right time for a reliable virological diagnosis.Copyright © 2022 by The Cardiovascular Thoracic Anaesthesia and Intensive Care.

Effectiveness of rapid immunochromatographic tests to the detection of feline Coronavirus

Feline coronavirus (FCoV) belongs among pathogens with common occurrence in the cats population in the whole world. FCoV is ubiquitous in environments with a higher concentration of cats, e.g. in shelters, multicat households and kennels. FCoV primarily attacks the digestive feline tract, replicates in its cells and is excreted in the feces to surroundings of permanently or transiently infected cats. The aim of the study was the detection of FCoV in the feces of newly admitted cats to the shelter by the qPCR method and by means of commercial rapid immunochromatographic (antigen) tests from three different producers. For each of the antigen tests, sensitivity and specifity were determined by comparison with the qPCR analysis result. Out of 70 examined fecal samples, viral RNA was by the qPCR analysis identified in 44 samples (62.9%). Neither the age nor the gender of cats played a significant role in the viral excretion. Found sensitivity of the antigen tests was at a low (< 35%;tests A and C) to a satisfactory level (> 50%, test B). The number of viral particles in the samples determined by the qPCR method did not correlate significantly with the result of the antigen tests. The results of this study suggest that the use of rapid antigen tests for routine screening of FCoV shedding in feline shelters is limited due to the high rate of false-negative results.

A study of Real-Time Non-invasive Detection Techniques to Identify COVID-19 contagious person

The whole world has witnessed the global pandemic situation caused and hampered very badly due to COVID-19. We had seen the adverse effect globally, in terms of health, economy, social lifestyle. So, it's an urgent need to find a rapid detection technique/test to avoid the spread of the virus. The most effective and world-wide accepted detection method of COVID-19 is the RT-PCR. But due to its slow detection time and False-negative rates, researchers and scientists are trying different detection methods such as use of GC-MS, E-nose, Electrochemical method, use of nanomaterial-based sensor arrays. But all these have limitations in terms of real time sensing, detection time, sample preparation, etc. In order to overcome said drawbacks and to get real-time analysis, we are proposing a concept for COVID-19 detection based on the reported literature. As per recent advancement researchers have evident the presence of VOCs in COVID-19 infected person's breath by GC-MS method. A real time system is very much necessary to detect the VOCs in the Exhaled breath of the COVID-19 infected person to minimize the burden of healthcare system. In this article we will discuss and propose the probable detection techniques for real time sensing of the VOCs presence in the Exhaled breath of the COVID-19 infected person. © Published under licence by IOP Publishing Ltd.

COVID-19: Test, Test and Test.

A new virus was identified in late December 2019 when China reported the first cases of pneumonia in Wuhan, and a global COVID-19 pandemic followed. The world was not late to respond, with a number of sweeping measures ranging from social distancing protocols, stringent hygienic practices, and nation-wide lockdowns, as well as COVID-19 testing campaigns in an attempt to prevent the transmission of the disease and contain the pandemic. Currently, different types of diagnostic testing have been adopted globally, such as nucleic acid detection tests, immunological tests and imaging approaches; however, real-time reverse transcriptase-polymerase chain reaction (RT-PCR) remains the "gold standard" for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Pre-analytical factors, such as specimen selection and collection, are crucial for RT-PCR, and any suboptimal collection may contribute to false-negative results. Herein, we address some of the specimen types that have been used in molecular detection methods for COVID-19. However, the pandemic is still evolving, and information might change as more studies are conducted.

Knowledge about, acceptance of and willingness to use over-the-counter COVID-19 self-testing kits

Objectives: Early investments in new diagnostic technologies that allow for rapid and decentralized testing were critical in reducing SARS-CoV-2's detrimental health and economic effects. This study evaluates public knowledge about, acceptance of and willingness to use COVID-19 self-testing kits. Methods: An online descriptive cross-sectional questionnaire was used in this study. The final study population included all contacted national and resident adults, age 18 and over, who were willing to engage in the study. The survey was divided according to participants' demographic information and 11 questions assessed the respondents' understanding of and willingness to use COVID-19 self-testing kits. The statistical analysis was carried out using SPSS version 24. Multivariate linear regression models were used to identify the factors influencing respondents' knowledge of and attitudes toward the acceptability of self-testing kits for COVID-19 and their willingness to use these kits. Key findings: A total of 876 respondents participated in the study and completed the whole questionnaire. The average knowledge score on the acceptability of and willingness to use self-testing kits for COVID-19 was 70.2%, with a 95% confidence interval (CI) [69.1%, 71.4%]. Participants who were postgraduate, female and vaccinated against COVID-19, as well as employees and older participants, were jointly highly associated with higher levels of knowledge about, acceptance of and willingness to use self-testing kits for COVID-19. Moreover, participants who had been infected with COVID-19, were vaccinated against COVID-19 or were female, employees, older, Western or Arabic were jointly highly associated with positive attitudes about the acceptability of and willingness to use self-testing kits for COVID-19. Conclusions: The majority of the respondents have acceptable levels of knowledge about, acceptance of and willingness to use self-testing kits for COVID-19. Nonetheless, future studies should consider the issues of pre- and post-test counselling, false negative results and the sale of unregulated testing kits. Additional information should be communicated so that people can make informed decisions and be protected from possible abuse of COVID-19 self-testing kits when they become available in pharmacies.

Evaluating a SARS-CoV-2 screening strategy based on serological tests.

BACKGROUND: facing the SARS-CoV-2 epidemic requires intensive testing on the population to early identify and isolate infected subjects. Although RT-PCR is the most reliable technique to detect ongoing infections, serological tests are frequently proposed as tools in heterogeneous screening strategies. OBJECTIVES: to analyse the performance of a screening strategy proposed by the local government of Tuscany (Central Italy), which first uses qualitative rapid tests for antibody detection, and then RT-PCR tests on the positive subjects. METHODS: a simulation study is conducted to investigate the number of RT-PCR tests required by the screening strategy and the undetected ongoing infections in a pseudo-population of 500,000 subjects, under different prevalence scenarios and assuming a sensitivity of the serological test ranging from 0.50 to 0.80 (specificity 0.98). A compartmental model is used to predict the number of new infections generated by the false negatives two months after the screening, under different values of the infection reproduction number. RESULTS: assuming a sensitivity equal to 0.80 and a prevalence of 0.3%, the screening procedure would require on average 11,167 RT-PCR tests and would produce 300 false negatives, responsible after two months of a number of contagions ranging from 526 to 1,132, under the optimistic scenario of a reproduction number between 0.5 to 1. Resources and false negatives increase with the prevalence. CONCLUSIONS: the analysed screening procedure should be avoided unless the prevalence and the rate of contagion are very low. The cost and effectiveness of the screening strategies should be evaluated in the actual context of the epidemic, accounting for the fact that it may change over time.

Real-world Data on the Incidence of Coronavirus Disease (COVID-19) in Patients With Advanced Thoracic Cancer During the Early Phase of the Pandemic in Japan.

BACKGROUND/AIM: The severity and associated mortality of coronavirus disease 2019 (COVID-19) are higher in patients with thoracic cancer than in healthy populations and those with other cancer types. Here, we investigated real-world data on the incidence of COVID-19 and false-negative cases using severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) real-time reverse-transcription polymerase chain reaction (rRT-PCR) testing in patients with thoracic cancer. PATIENTS AND METHODS: We retrospectively reviewed patients with advanced thoracic cancer at the National Cancer Center Hospital between March 2020-May 2021. Blood samples were collected and evaluated for IgM and IgG antibodies specific for nucleocapsid (N) and spike (S) protein SARS-CoV-2 before and after rRT-PCR testing. False-negative cases were assessed based on anti-SARS-CoV-2 antibody levels before and after rRT-PCR testing. RESULTS: A total of 2,107 patients with thoracic cancer were identified between March 2020 and May 2021, 7 (0.3%) of whom developed COVID-19. Among the 218 patients who underwent at least one rRT-PCR test because of suspected COVID-19 symptoms or as a screening test at our institute, the most common diagnosis was non-COVID-19 pneumonia (34.4%), followed by tumor fever (30.7%). Furthermore, of the 218 patients, 120 paired serum samples before and after rRT-PCR testing were available. Seroconversion was identified in all three patients with positive SARS-CoV-2 rRT-PCR results but was only observed in 1 out of the 117 patients who tested negative; the rate of false-negative cases was low (0.9%). CONCLUSION: COVID-19 incidence among patients with advanced thoracic cancer was low during the early phase of the pandemic in Japan.

An Automated Facemask Detection For Covid-19 Using Viola-Jones Algorithm

Corona Virus Disease (Covid-19) is a label species of the Corona virus family. It can cause a variety of illnesses, from the ordinary cold to advanced respiratory syndromes like Middle-East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS). This virus is highly contagious and spreads due to the droplets produced by coughing and sneezing. Though there are several ways to prevent the transmission of Covid-19, one of the most important and effective way is using a face mask or a face shield. In this paper, we constructed face mask detection framework using Viola-Jones algorithm in order to recognize whether an individual is wearing a mask or not. This algorithm includes the selection of Haar features of a face, integral image creation, adaptive boost training and cascading. An extensive study is carried out in order to analyze the performance of the proposed approach;we use a large facial image dataset from the publicly available MAFA dataset. The results indicate the proposed method can accurately identify face mask wearing images with a classifier accuracy of 98.26%, suggesting it might be useful in Covid-19 prevention. Copyright © 2022 Wolters Kluwer Medknow Publications. All rights reserved.

Molecular Diagnostic Tools against SARS-CoV-2 in Poland in 2022.

The most effective way to stop the spread of COVID-19 (coronavirus disease 2019) is to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and isolate those infected as soon as possible. More than 1000 types of molecular and antigen-based immunoassay tests to detect SARS-CoV-2 are now commercially available worldwide. In this review, we present the possibilities of molecular diagnostics available in Poland in 2022. We provide a description of what samples have proven useful to confirm SARS-CoV-2 infection, we describe what methods are used, as well as what safeguards can and should be used to prevent false-negative and false-positive results, and finally we review the products that diagnostic laboratories have to choose from. We also describe diagnostic problems associated with the mutation of the virus.