Negative Reverse Transcription-polymerase Chain Reaction Research Articles

Evaluation of Serum Pentraxin-3 and suPAR Levels as Acute Phase Reactants in Patients with COVID-19

Coronavirus disease-2019 (COVID-19) is the most challenging health problem of our century, but our knowledge about the disease is limited. Most individuals infected with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which causes COVID-19, have mild symptoms such as headache, sore throat, joint pain, loss of sense of taste and smell. However, infection also causes significant morbidity and mortality, especially in individuals over 65 years of age with comorbidities. However, it is not known exactly which patients will have a poor prognosis. In this study, it was aimed to determine serum Pentraxin-3 (PTX3) and soluble urokinase plasminogen activator receptor (suPAR) levels in COVID-19 patients, and to evaluate the relationship between PTX3 and suPAR levels and the clinical status of the disease. This study was conducted with 150 patients who were confirmed to have COVID-19 by microbiological or clinical/radiological methods between April 1 and December 31, 2020. Thirty people with no known history or symptoms of COVID-19 and negative reverse transcription-polymerase chain reaction (RT-PCR) results also constituted the control group. Patients admitted to inpatient services due to COVID-19 constituted the service group (n= 75) and patients admitted to the intensive care unit (ICU) constituted the ICU group (n= 75). Serum PTX3 and suPAR levels were analyzed by enzyme-linked immunoassay (ELISA) and the results were compared between the three groups. The patients' leukocyte, neutrophil, neutrophil/lymphocyte ratio (NLR), troponin, procalcitonin (PCT), D-dimer, C-reactive protein (CRP), lymphocyte and ferritin results were included in the analysis. The mean age of the patients was 67.2 ± 11.8, and 62.0 ± 8.4 in the control group. There was no significant difference between the groups in terms of female/male ratio (p= 0.582). The PTX3 and suPAR levels of the patients were higher than the controls (p= 0.001, p= 0.023, respectively). PTX3 and suPAR levels were higher in the service group than the ICU group (p<0.001, p= 0.004, respectively) and the control group (p<0.001, p= 0.001, respectively). However, PTX3 (p= 0.291) and suPAR (p= 0.411) concentrations did not differ between ICU and control groups. The most determining parameters in ICU admission were found to be leukocytes (AUC= 0.840), neutrophils (AUC= 0.840), and NLR (AUC= 0.835), respectively. The most predictive parameters for mortality were PCT (AUC= 0.712), NLR (AUC= 0.708) and D-dimer (AUC= 0.695), respectively. In our study, serum PTX3 and suPAR concentrations were found to be high in COVID-19 patients. In patients admitted to the ICU, PTX3 and suPAR levels were observed at low levels. Low levels of PTX3 and suPAR in COVID-19 patients were thought to be clinically important.

208 Performance Assessment of Electronic Nose Device for Detection of COVID-19 in Breath Samples

Novel methods of rapid and large-scale testing for COVID-19 infection are necessary during the ongoing pandemic. Although common test samples are nasopharyngeal and oral specimens, breath analysis has also been proposed for COVID-19 detection. Our study objective was to evaluate the performance of the electronic nose (eNOSE), a portable breath testing device developed by the National Aeronautics and Space Administration (NASA) for the diagnosis of COVID-19 infection. The eNOSE sensor is approximately 6 inches by 3 inches by 3 inches and analyzes breath samples to detect combinations of volatile organic compounds (VOCs) diagnostic of SARS-CoV-2 virus infection. Following Institutional Review Board and Biosafety Committee approvals, we recruited adults with a previous positive COVID-19 nasopharyngeal reverse transcription polymerase chain reaction (RT-PCR) test and volunteers with unknown infection status. During the study visit, we collected breath samples and introduced it to the eNOSE device for VOC sensing. Concurrently, participants provided anterior nares samples for RT-PCR testing for COVID-19. Cases were those who had a positive RT-PCR and the controls were those who had a negative RT-PCR at the time of breath sample collection. The sensitivity and specificity of the eNOSE device were calculated using the concurrent RT-PCR test as the gold standard. There were 64 participants enrolled, with a mean age of 42 years (SD +13 years) and of whom 44 (69%) were female. We recruited 54 previously COVID-19 positive participants and 10 participants with unknown infection status. At the time of breath collection, there were 32 RT-PCR positives, 31 RT-PCR negatives, and one untestable sample. Of those with a RT-PCR positive result, 21 had a positive eNOSE result and 11 had a negative eNOSE result. Of those with RT-PCR negative result, 21 had a negative eNOSE result and 10 had a positive eNOSE result. The eNOSE device was 66% sensitive and 68% specific for the detection of COVID- 19 infection. The mean time from recruitment to enrollment was 7 days (SD +7 days). From the limited data set collected to date, the eNOSE device had moderate sensitivity and specificity for the diagnosis of COVID-19 infection. Both parameters are expected to improve as more samples are analyzed. Our next step is to include cycle threshold (Ct) values in the analysis to learn if the eNOSE response is correlated with vira

Development of a Fully Automated Desktop Analyzer and Ultrahigh Sensitivity Digital Immunoassay for SARS-CoV-2 Nucleocapsid Antigen Detection.

Background: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak has had a significant impact on public health and the global economy. Several diagnostic tools are available for the detection of infectious diseases, with reverse transcription-polymerase chain reaction (RT-PCR) testing specifically recommended for viral RNA detection. However, this diagnostic method is costly, complex, and time-consuming. Although it does not have sufficient sensitivity, antigen detection by an immunoassay is an inexpensive and simpler alternative to RT-PCR. Here, we developed an ultrahigh sensitivity digital immunoassay (d-IA) for detecting SARS-CoV-2 nucleocapsid (N) protein as antigens using a fully automated desktop analyzer based on a digital enzyme-linked immunosorbent assay. Methods: We developed a fully automated d-IA desktop analyzer and measured the viral N protein as an antigen in nasopharyngeal (NP) swabs from patients with coronavirus disease. We studied nasopharyngeal swabs of 159 and 88 patients who were RT-PCR-negative and RT-PCR-positive, respectively. Results: The limit of detection of SARS-CoV-2 d-IA was 0.0043 pg/mL of N protein. The cutoff value was 0.029 pg/mL, with a negative RT-PCR distribution. The sensitivity of RT-PCR-positive specimens was estimated to be 94.3% (83/88). The assay time was 28 min. Conclusions: Our d-IA system, which includes a novel fully automated desktop analyzer, enabled detection of the SARS-CoV-2 N-protein with a comparable sensitivity to RT-PCR within 30 min. Thus, d-IA shows potential for SARS-CoV-2 detection across multiple diagnostic centers including small clinics, hospitals, airport quarantines, and clinical laboratories.

Effects of Chlorhexidine and Povidone-Iodine on the SARS-CoV-2 Load: A Systematic Review and Meta-analysis.

The efficacy of mouthwash for reducing the viral load in patients with the novel coronavirus disease 2019 (COVID-19) remains unclear. This systematic review and meta-analysis comprehensively examined the effects of chlorhexidine (CHX) and povidone-iodine (PVP-I) on the viral load in patients with COVID-19. We performed methodological analysis, systematic review, and meta-analysis of included studies using the Comprehensive Meta-analysis Software. PubMed, EMBASE, Cochrane Library, and ProQuest were searched from December 1, 2019, to December 2, 2021. In total, we included 10 studies of 1,339 patients with COVID-19. Compared with the control group, both CHX and PVP-I significantly reduced the number of negative reverse-transcription polymerase chain reaction (RT-PCR) results (p<0.001) among COVID-19 patients. The CHX and PVP-I were effective on reducing the number of negative RT-PCR results in COVID-19 patients. Additional studies using adequate randomization methods and larger samples are warned.

HRCT CHEST EVALUATION OF SEQUELAE OF COVID-19 PNEUMONIA

Since December 2019, many unexplained cases of pneumonia have been reported, as a result of exposure in Wuhan city, Hubei province, China. The pathogen identied was coronavirus and the disease was named COVID-19 by World Health Organization (WHO). Based on the epidemiological surveys done, dry cough, fever and fatigue were the main clinical manifestations reported.(Huang et al., 2020; X. Liu et al., 2020) Few patients had symptoms such as runny nose, nasal obstruction, myalgia, sore throat, and diarrhoea. Seriously ill patients rapidly progressed to ARDS. The COVID-19 outbreak has been declared public health emergency of international concern by the WHO. A specic viral nucleic acid assay, real time reverse transcription-polymerase chain reaction (RT-PCR) was developed to diagnose COVID-19. However, published literature on COVID-19 pneumonia showed some patients with initial negative RT-PCR results. According to current literature, HRCT thorax may show abnormalities earlier than even RT-PCR(Zhou et al., 2020). Therefore, high resolution CT had been included as one of the main tools particularly for screening and in the evaluation of the severity of disease (Salameh et al., 2020) Although most of the patients showed complete resolution from illness, some of the them were likely to have some kind of long-term lung damage. Radiological ndings have proven to be helpful in estimating the course of the disease and they can be used to evaluate long-term consequences of the disease. CT had been recommended as an important tool for screening and also for evaluation of severity of the illness.(Dai et al., 2020; Shah et al., 2021) AIM: Ÿ Aim of the study was to determine the sequelae of COVID-19 pneumonia in positive patients 4 – 8 weeks after RT-PCR negative report. OBJECTIVE: Ÿ To describe the HRCT chest ndings of sequelae of COVID-19 pneumonia- GGO, brosis, bronchovascular bundle distortion and small pleural effusion. Ÿ To explore the relevant factors affecting the sequelae - initial clinical symptoms of onset, risk factors, age, and gender and laboratory examinations. Ÿ To determine the cumulative percentage of complete radiological resolution - using CT severity score

Efficacy of Hexetidine, Thymol and Hydrogen Peroxide-Containing Oral Antiseptics in Reducing Sars-Cov-2 Virus in the Oral Cavity: A Pilot Study

Background: Studies have demonstrated the role of sputum as a site of severe acute respiratory syndrome-coronavirus-2 (SARSCoV-2) transmission. However, there is limited literature on the virucidal efficacy of oral antiseptics against SARS-CoV-2 virus. This study investigated the virucidal efficacy of three oral-antiseptics compared to a placebo-control in the sputum of SARS-CoV-2 infected individuals.&#x0D; Methodology: A pilot study of adults with SARS-CoV-2 positive results, as determined by reverse transcription-polymerase chain reaction (RT-PCR) of &lt;7 days. The oral antiseptics investigated were: Hexetidine (0.1% w/v); Thymol (0.063% w/v) and H2O2(1.5%) compared to de-mineralized sterile water (Placebo-control). The primary outcome measure was the proportion of negative RT-PCR results at 15-mins, 30-mins, 1-hour, 2-hours and 4-hours After Oral antiseptics Interventions (AOI) compared to the placebo-control. Statistical analysis was done using STATA 15.0 software with p-values of &lt;0.05 considered statistically significant.&#x0D; Results: Data from a total of 66 participants that were RT-PCR SARS-CoV-2 positive at baseline (0-min) was analysed. At 15-mins AOI, the highest proportion of negativation from sputum samples was observed in the Hexedine group, with 69.2% of the baseline PCR positive cases converting to negative compared to 46.7% in the placebo-control group. In addition, H2O2 demonstrated efficacy at 2-hours AOI compared to placebo-control (62.5% vs 37.5% respectively) and other oral-antiseptics. Across all time-points, the oral-antiseptic groups compared to the placebo-control group, there was no statistically significant difference in the proportion of sputum samples which converted to a negative status (p&gt;0.05).&#x0D; Conclusion: The findings in this study suggest there was no significant difference in the proportion of participants who converted to a negative sputum status across the treatment groups at various time points. Future studies could compare the cycle threshold (ct) viral titre values of sputum samples to determine quantitative differences.&#x0D; Authors&#x0D; S A Ogun 1, O Erinoso 2, O O Aina 3, O I Ojo 2, O Adejumo 4, A Adeniran 2, A Bowale 4, C A Olaniyi 2, B M Adedoyin 5, B Mutiu 6, B Saka 6, O Oshinaike 2, W Arabambi 1, F Adejumo 4, O Shuaib 2, A O Salmon 2, H Abdur-Razzaq 7, O F Njokanma 2, O Ojini 8, O Ogboye 7, O Lajide 7, K O Wright 2, A Osibogun 8, A Abayomi 7

CHEST CT VS RT-PCR FOR THE DETECTION OF COVID-19: SYSTEMATIC REVIEW AND META-ANALYSIS OF COMPARATIVE STUDIES

TYPE: Abstract TOPIC: Chest Infections PURPOSE: To compare the performance of chest computed tomography (CT) scan versus reverse transcription polymerase chain reaction (RT-PCR) as the reference standard in the initial diagnostic assessment of coronavirus disease 2019 (COVID-19) patients. METHODS: A systematic review and meta-analysis were performed as per the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. A search of electronic information was conducted using the following databases: MEDLINE, EMBASE, EMCARE, CINAHL and the Cochrane Central Register of Controlled Trials. Thirteen non-randomised studies enrolling 4092 patients were identified. Sensitivity, specificity and accuracy were primary outcome measures. Secondary outcomes included other test performance characteristics and discrepant findings between both investigations. RESULTS: Chest CT had a median sensitivity, specificity and accuracy of 0.91 (range 0.82–0.98), 0.775 (0.25–1.00) and 0.87 (0.68–0.99), respectively, with RT-PCR as the reference. Importantly, early small, China-based studies tended to favour chest CT versus later larger, non-China studies. CONCLUSIONS: A relatively high false positive rate can be expected with chest CT. It is possible it may still be useful to provide circumstantial evidence, however, in some patients with a suspicious clinical presentation of COVID-19 and negative initial Severe Acute Respiratory Syndrome Coronavirus 2 RT-PCR tests, but more evidence is required in this context. In acute cardiorespiratory presentations, negative CT scan and RT-PCR tests is likely to be reassuring. CLINICAL IMPLICATIONS: This study provides useful information regardnig which reference standard in the initial diagnostic assessment of coronavirus disease 2019 (COVID-19) patients between chest CT versus RT-PCR DISCLOSURE: Nothing to declare. KEYWORD: COVID-19

False-negative rate of SARS-CoV-2 RT-PCR tests and its relationship to test timing and illness severity: A case series.

ObjectiveTo determine the false-negative rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse-transcription polymerase chain reaction (RT-PCR) test results, and to describe the characteristics of coronavirus disease 2019 (COVID-19) patients with false-negative results.MethodsWe validated SARS-CoV-2-positive RT-PCR test results performed in hospitalized patients between February 1 and August 31, 2020 and classified the patients according to disease severity.ResultsIn total, 2038 SARS-CoV-2 RT-PCR tests were performed on 1890 patients. Of these, 145 patients had positive results and were diagnosed with COVID-19. Among the 145 patients with COVID-19, the initial RT-PCR tests were negative in five patients. Of these, three had moderate illness and were initially tested in the early stage of disease, and two had severe illness and were initially tested in the late stage of disease, when RT-PCR testing has lower sensitivity due to viral clearance.ConclusionsThese findings suggest that false-negative results can be caused by both observer errors and by low viral RNA levels in the later stages of disease, after the infection has cleared. Clinicians should be aware that patients with COVID-19 can have negative RT-PCR test results in the later stages of infection.

Compassionate Use of REGEN-COV® in Patients With Coronavirus Disease 2019 (COVID-19) and Immunodeficiency-Associated Antibody Disorders.

BackgroundPatients with immunodeficiency-associated antibody disorders are at a higher risk of prolonged/persistent COVID-19 infection, having no viable treatment options.MethodsA retrospective analysis of patients with primary and/or secondary immunodeficiency-associated antibody disorders who received casirivimab and imdevimab (REGEN-COV®) under emergency compassionate use. Objective were to describe safety and response to REGEN-COV, focusing on the subset of patients who had COVID-19 duration ≥21 days before treatment.ResultsQuantitative (change in oxygenation status and/or viral load) and/or qualitative (physician-reported clinical status) outcomes data are reported from 64 patients. Improvement in ≥1 outcome was observed in 90.6% of the overall patient group. Thirty-seven of these had COVID-19 duration ≥21 days before treatment; median time from diagnosis to REGEN-COV treatment was 60.5 days. Of the 29 patients with COVID-19 duration ≥21 days before treatment and available outcome data, 96.6% showed improvement in ≥1 outcome. In the 14 patients with post-treatment reverse transcription–polymerase chain reaction (RT-PCR) results available, 11 (78.6%) reported a negative RT-PCR following treatment, with 5 (45.5%) and 8 (72.7%) patients reporting a negative RT-PCR within 5 days and 21 days of treatment, respectively. Ten of 85 patients (11.8%) experienced serious adverse events; only one was an infusion-related reaction, possibly related to REGEN-COV. Two deaths were reported; neither were attributed to REGEN-COV.ConclusionsIn this retrospective analysis of immunodeficient patients granted REGEN-COV under emergency compassionate use, REGEN-COV treatment was associated with rapid viral clearance and clinical improvement in patients with longstanding COVID-19. Adverse events were consistent with COVID-19 and its associated complications, and due to patients’ concurrent medical conditions.

Uji diagnostik uji antigen sars-cov-2 pada pemeriksaan laboratorium covid-19

The performance characteristics of the rapid SARS-CoV-2 antigen detection test should be evaluated and compared with the reverse transcription-polymerase chain reaction (RT-PCR) assay as the standard for diagnosis of COVID-19 cases. This research is a descriptive observational study with a cross-sectional research design. Secondary data from suspected COVID-19 patients who were examined for SARS-CoV-2 antigen and the results of RT-PCR in January - April 2021 at the Beriman Hospital of Balikpapan City, which was 336 samples. Based on the results of the study, the number of samples with an antigen-positive test for SARS-CoV-2 and a positive RT-PCR result was 114 (33.93%), the number of samples with an antigen-positive test for SARS-CoV-2 and a negative RT-PCR result was 2 (0.6%), the number of samples with positive SARS-CoV-2 antigen-negative test results and RT-PCR was 23 (6.85%), and the number of samples with SARS-negative antigen-negative test and RT-PCR results CoV -2 and negative PCR were 197 (58.63%). The result of the SARS-CoV-2 antigen sensitivity was 83.21%, while the specificity was 98.99%. The accuracy value of the SARS-CoV-2 antigen is 92.56%. The rapid antigen test used in this study has sensitivity and specificity as recommended by WHO, so it is suitable for use for COVID-19 laboratory tests.

No antibody response in cutaneous manifestations associated with COVID-19: An observational study of 64 cases with microbiological and clinical characterization.

Background: The microbiological diagnosis of skin lesions related to COVID‐19 is not well known. Objective: Perform a microbiological diagnosis in COVID19‐related cutaneous manifestations. Methods: A cross‐sectional study was performed with 64 patients with cutaneous manifestations associated with COVID‐19 who underwent serological and nasopharyngeal reverse transcription polymerase chain reaction (RT‐PCR) for SARS‐CoV‐2. Results: Out of the 64 patients, 6 patients had positive RT‐PCR, with all of them developing SARS‐CoV‐2 IgG and 4 of them had positive IgM + IgA. Of the 58 patients with negative RT‐PCR, 8 cases had positive IgM + IgA and only one of them had IgG seroconversion. Therefore, the infection was demonstrated in 7 cases (10.9%) and was doubtful in 7 other cases (10.9%) who presented negative RT‐PCR and presence of IgA + IgM without subsequent seroconversion of IgG. Fifty patients (78.1%) had negative serological tests. The most frequent cutaneous pattern was pseudo‐chilblain (48.4%) followed by maculo‐papular pattern (26.6%), urticarial lesions (10.9%), vesicular eruptions (6.3%) and livedoid pattern (4.7%). The maculo‐papular pattern showed the highest positivity in RT‐PCR (3 cases; 17.6%) and serologies (4 cases; 23.5%). Skin lesions developed after the systemic symptoms in most patients (19 cases; 61.3%). Conclusions: Microbiological confirmation tests may not be an effective diagnostic technique for COVID‐related cutaneous manifestations or that attributed lesions are not related to COVID‐19. Confounding factors such as adverse drug reaction, serological cross‐reactions with other viruses, the low production of antibodies in asymptomatic or mild forms of COVID‐19 or its rapid disappearance, increase diagnostic uncertainty.

Clinical Usefulness of Nested Reverse-Transcription Polymerase Chain Reaction for the Diagnosis of Severe Fever with Thrombocytopenia Syndrome.

Severe fever with thrombocytopenia syndrome (SFTS), caused by SFTS virus (SFTSV) is an emerging tick-borne infectious disease. Few studies have assessed the clinical usefulness of nested reverse-transcription polymerase chain reaction (RT-PCR) for diagnosing SFTS. We performed conventional RT-PCR targeting the M segment, nested RT-PCR targeting M and S segments, and real-time RT-PCR targeting the S segment of SFTSV for four patients with suspected SFTS. Although conventional RT-PCR results for the first two patients were negative at admission, nested RT-PCR using the S or M targets was positive for the same samples. Likewise, in the other two patients, initial samples were confirmed positive in all three tests, but follow-up testing demonstrated negative conventional RT-PCR and positive nested RT-PCR results. Thus, delayed testing using conventional RT-PCR or real-time RT-PCR in symptomatic patients with SFTS may result in missed diagnoses, and compared with these methods, nested RT-PCR may increase the window for obtaining positive SFTSV PCR results. Meanwhile, the indirect immunofluorescence assay showed seroconversion to SFTSV antibodies in all four patients. Nested RT-PCR for SFTSV M and S segments could help diagnose SFTS in patients testing negative by conventional RT-PCR.

Live Kidney Donor with a History of COVID-19 Infection

Transplant in COVID era is a challenging task given a paucity of data and limited experience worldwide. A 35-year-old male patient with chronic kidney disease on dialysis for the past 9 months underwent successful living-related donor transplant with his father (aged 64 years) as donor at our center. In this case, donor was diagnosed with reverse-transcription polymerase chain reaction (RT-PCR)-confirmed COVID-19 during evaluation, and he was managed with supportive care and comprehensive social distancing at home. Donor was asymptomatic throughout this period. Interval from positive to negative RT-PCR for nasopharyngeal swab test was 37 days. Interval from negative RT-PCR to kidney transplant was 33 days. Later, recipient and donor were discharged with negative RT-PCR posttransplant. At 71 days of follow-up, both recipient and donor have stable kidney function with normal urinalysis. Hence, prospective donor with a history of COVID-19 infection can be taken for transplant after thorough pretransplant evaluation and having two negative RT-PCR reports after infection, normal imaging, and additional preprocedural negative RT-PCR testing.

Role of serological rapid antibody test in the management of possible COVID-19 cases.

BACKGROUNDAlthough the detection of viral particles by reverse transcription polymerase chain reaction (RT-PCR) is the gold standard diagnostic test for coronavirus disease 2019 (COVID-19), the false-negative results constitute a big challenge.AIMTo examine a group of patients diagnosed and treated as possible COVID-19 pneumonia whose multiple nasopharyngeal swab samples were negative for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by RT-PCR but then serological immunoglobulin M/immunoglobulin G (IgM/IgG) antibody against SARS-CoV-2 were detected by rapid antibody test.METHODSEighty possible COVID-19 patients who had at least two negative consecutive COVID-19 RT-PCR test and were subjected to serological rapid antibody test were evaluated in this study.RESULTSThe specific serological total IgM/IgG antibody against SARS-CoV-2 was detected in twenty-two patients. The mean age of this patient group was 63.2± 13.1-years-old with a male/female ratio of 11/11. Cough was the most common symptom (90.9%). The most common presenting chest computed tomography findings were bilateral ground glass opacities (77.2%) and alveolar consolidations (50.1%). The mean duration of time from appearance of first symptoms to hospital admission, to hospital admission, to treatment duration and to serological positivity were 8.6 d, 11.2 d, 7.9 d, and 24 d, respectively. Compared with reference laboratory values, serologically positive patients have shown increased levels of acute phase reactants, such as C-reactive protein, ferritin, and procalcitonin and higher inflammatory markers, such as erythrocyte sedimentation rate, lactate dehydrogenase enzyme, and fibrin end-products, such as D-dimer. A left shift on white blood cell differential was observed with increased neutrophil counts and decreased lymphocytes.CONCLUSIONOur study demonstrated the feasibility of a COVID-19 diagnosis based on rapid antibody test in the cases of patients whose RT-PCR samples were negative. Detection of antibodies against SARS-CoV-2 with rapid antibody test should be included in the diagnostic algorithm in patients with possible COVID-19 pneumonia.

English

BACKGROUND With the emerging pandemic of corona virus disease 19 (Covid-19) infection around the world, the need to identify the course of this disease in pregnant women becomes the need of the hour. Its effect on pregnancy and the neonatal outcome is not well known because of lack of any reliable data. We wanted to evaluate the clinical features, laboratory manifestations and obstetric outcome of Covid-19 in the term of antenatal mothers who were either admitted in labour, induction of labour or elective caesarean section and rule out vertical transmission by doing a routine neonatal screening for Covid-19. METHODS A descriptive cross-sectional study conducted at Sri Ramachandra Medical College &amp; Research Institute, Chennai from March 2020 to September 2020 includes all antenatal women who were tested positive for severe acute respiratory syndrome (SARS- Cov2) reverse transcription - polymerase chain reaction (RT-PCR). 43 Covid positive patients were included in the study. RESULTS Incidence of Covid positive antenatal women was found to be 1.7 %. Only 3 % were symptomatic with mild disease. Gestational diabetes mellitus accounted for (27 %), Class II obesity (7 %), hypertensive disorders of pregnancy (13 %) of the screen positive mothers. 20 % of the labouring women had meconium-stained liquor. Lymphopenia was seen in 73 % of cases. Elevated d-dimer in 13 %, requiring thromboprophylaxis. Negative RT-PCR for SARS-CoV-2 in the neonates ruled out vertical transmission. CONCLUSIONS Covid-19 in pregnancy is more common in those with gestational diabetes, obesity, with development of complications like hypertension and meconium-stained liquor. The impact of Covid-19 is not as disabling as it is in the non-pregnant population. KEY WORDS Universal Screening, In/Near Labour, Lymphopenia, Thromboprophylaxis, Meconium- Stained Amniotic Fluid.

Quantitative CT for detecting COVID\u201119 pneumonia in suspected cases

BackgroundCorona Virus Disease 2019 (COVID-19) is currently a worldwide pandemic and has a huge impact on public health and socio-economic development. The purpose of this study is to explore the diagnostic value of the quantitative computed tomography (CT) method by using different threshold segmentation techniques to distinguish between patients with or without COVID-19 pneumonia.MethodsA total of 47 patients with suspected COVID-19 were retrospectively analyzed, including nine patients with positive real-time fluorescence reverse transcription polymerase chain reaction (RT-PCR) test (confirmed case group) and 38 patients with negative RT-PCR test (excluded case group). An improved 3D convolutional neural network (VB-Net) was used to automatically extract lung lesions. Eight different threshold segmentation methods were used to define the ground glass opacity (GGO) and consolidation. The receiver operating characteristic (ROC) curves were used to compare the performance of various parameters with different thresholds for diagnosing COVID-19 pneumonia.ResultsThe volume of GGO (VOGGO) and GGO percentage in the whole lung (GGOPITWL) were the most effective values for diagnosing COVID-19 at a threshold of − 300 HU, with areas under the curve (AUCs) of 0.769 and 0.769, sensitivity of 66.67 and 66.67%, specificity of 94.74 and 86.84%. Compared with VOGGO or GGOPITWL at a threshold of − 300 Hounsfield units (HU), the consolidation percentage in the whole lung (CPITWL) with thresholds at − 400 HU, − 350 HU, and − 250 HU were statistically different. There were statistical differences in the infection volume and percentage of the whole lung, right lung, and lobes between the two groups. VOGGO, GGOPITWL, and volume of consolidation (VOC) were also statistically different at the threshold of − 300 HU.ConclusionsQuantitative CT provides an image quantification method for the auxiliary diagnosis of COVID-19 and is expected to assist in confirming patients with COVID-19 pneumonia in suspected cases.

Role of CT Scan in Diagnosis of COVID-19 Infection- A Review

Since it was declared a worldwide pandemic, COVID-19 has ravaged almost all over the world and has overloaded several health-care systems. The pandemic also resulted in job losses as a result of lengthy shutdowns, which burdened the global economy. Even though significant clinical research progress has led to a better perceiving of the virus (SARS-CoV-2) nature and the disease (COVID-19) management, preventing the virus's spread has become a major concern as SARS-CoV-2 continues to wreak havoc around the world. Several countries suffered from the second or third wave of viral disease outbreaks, primarily caused by the mutation of SARS-CoV-2. Imaging is critical in the diagnosis and follow-up of patients with new coronavirus-infected pneumonia (NCIP). The primary imaging modality in clinically suspected cases is CT scan and it is useful for monitoring imaging changes following therapy. Therefore, CT is regarded as a useful diagnostic technique for clinically suspected cases of COVID-19. CT has the ability to detect patients who have a negative reverse transcription–polymerase chain reaction (RT-PCR) but are highly suspicious of NCIP in terms of clinical problems. In addition, the results of a CT scan may also reveal information concerning the severity of the condition. In this review article, the diagnosis of COVID-19 is discussed and CT characteristics are defined based on the newest research for the diagnosis and management of COVID-19.

In COVID-19 patients, low 25-hydroxyvitamin D level in serum is associated with longer viral clearance time and higher risk of intensive care unit admission

PurposeThis study aims to investigate the association between vitamin D measured in serum 25 hydroxyvitamin D [25(OH)D] and outcomes of COVID-19 patients in Bahrain. This paper hypothesized that lower serum 25(OH)D concentration in COVID 19 patients is associated with longer viral clearance time (VCT) and higher risk of admission to the intensive care unit (ICU).Design/methodology/approachThis study used a retrospective cohort design of patients admitted to Salmaniya Medical Complex, Manama, Kingdom of Bahrain, from February to June 2020. This study included patients with positive, confirmed COVID-19 diagnosis made using reverse transcription-polymerase chain reaction (RT-PCR), World Health Organization diagnosis manual and local diagnostic guidelines. Primary outcome measures were: VCT measured as the time in days between the first positive RT-PCR test result and the first of two consecutive negative RT-PCR results on recovery and admission need to ICU.FindingsA total of 450 patients were analyzed; mean age was 46.4 ± 12.4 years and 349 (78%) were men. Mean 25(OH)D concentration was 41.7 ± 23.7 nmol/L for the entire sample. Severe vitamin D deficiency (<25 nmol/L) was present in 20%, mild-to-moderate deficiency (25–50 nmol/L) in 55%, insufficiency (50 to <75 nmol/L) in 18% and sufficiency (=75 nmol/L) in 7%. The mean VCT was 12.9 ± 8.2 days. Multivariate linear regression analysis showed that severe vitamin D deficiency was associated with longer VCT, with an average of three extra days after correction for age and sex (β = 3.1; p = 0.001). Multinomial regression analysis showed that vitamin D deficiency was associated with an 83% increased risk of admission to ICU after correction for age and sex (odds ratio = 1.8; p = 0.03).Originality/valueThe results showed that severe vitamin D deficiency was associated with longer recovery time from COVID-19. Low serum 25(OH)D is associated with increased need for critical care in an ICU. Large-scale randomized controlled trials are necessary to further investigate the complex association between vitamin D and COVID-19 infection.

Tool for Estimating the Probability of Having COVID-19 With 1 or More Negative RT-PCR Results.

Early case detection and isolation of infected individuals are critical to controlling coronavirus disease 2019 (COVID-19). Reverse transcription polymerase chain reaction (RT-PCR) is considered the gold standard for the diagnosis of severe acute respiratory syndrome coronavirus 2 infection, but false negatives do occur. We built a user-friendly online tool to estimate the probability of having COVID-19 with negative RT-PCR results and thus avoid preventable transmission.

Scat-NET: COVID-19 diagnosis with a CNN model using scattergram images

The acute respiratory syndrome COVID-19 disease, which is caused by SARS-CoV-2, has infected many people over a short time and caused the death of more than 2 million people. The gold standard in detecting COVID-19 is to apply the reverse transcription polymerase chain reaction (RT-PCR) test. This test has low sensitivity and produces false results of approximately 15%–20%. Computer tomography (CT) images were checked as a result of suspicious RT-PCR tests. If the virus is not infected in the lung, the virus is not observed on CT lung images. To overcome this problem, we propose a 25-depth convolutional neural network (CNN) model that uses scattergram images, which we call Scat-NET. Scattergram images are frequently used to reveal the numbers of neutrophils, eosinophils, basophils, lymphocytes and monocytes, which are measurements used in evaluating disease symptoms, and the relationships between them. To the best of our knowledge, using the CNN together with scattergram images in the detection of COVID-19 is the first study on this subject. Scattergram images obtained from 335 patients in total were classified using the Scat-NET architecture. The overall accuracy was 92.4%. The most striking finding in the results obtained was that COVID-19 patients with negative RT-PCR tests but positive CT test results were positive. As a result, we emphasize that the Scat-NET model will be an alternative to CT scans and could be applied as a secondary test for patients with negative RT-PCR tests.