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1.
Acta Inform Med ; 29(1): 45-50, 2021 Mar.
Article in English | MEDLINE | ID: covidwho-1811118

ABSTRACT

BACKGROUND: Since December 2019. millions of people in the world have been affected with the novel Coronavirus disease-2019 (COVID-19) pandemic, and high economic impact has affect many countries especially low socioeconomic one like Iraq due to the high cost and limited availability of RT-PCR for diagnosis of COVID-19, so there should be predictive low cost easily available laboratory tests that can be used before proceeding to the high cost techniques. OBJECTIVE: In this retrospective study we aimed to evaluate the diagnostic accuracy of CRP, ferritin, LDH and D-dimer in predicting positive cases of COVID-19 in Iraq. METHODS: It is a retrospective observational cohort study based on STARD guidelines to determine the diagnostic accuracy of (CRP, LDH, ferritin and D dimer) for COVID-19 of electronic medical records of private medical center in Najaf city, at which 566 individuals were recruited. The investigated subjects were either in close contact with previously COVID-19 positive patients or have one or more symptoms of COVID-19. They were categorized into 2 groups, 205 subjects diagnosed with RT-PCR as COVID-19 negative, and 361 COVID-19 positive patients, results of study variables of the cohort were recruited from the medical records. RESULTS: Combining of these parameters had the following findings: CRP + ferritin; AUC: 0.77 with 55% sensitivity and 97% specificity, Ferritin + LDH; AUC: 0.83 with 65% sensitivity and 92% specificity, CRP+LDH; AUC: 0.78 with 56% sensitivity and 98% specificity, CRP + LDH + ferritin; AUC: 0.85, with 73% sensitivity and 88% specificity, CRP + LDH + ferritin + D dimer; AUC: 0.85 75% sensitivity and 87% specificity. CONCLUSION: Combination of routine laboratory biomarkers (CRP, LDH and ferritin ±D dimer) can be used to predict the diagnosis of COVID-19 with an accepted sensitivity and specificity before proceeding to definitive diagnosis by RT-PCR.

2.
Rev Esp Quimioter ; 33(6): 444-447, 2020 Dec.
Article in Spanish | MEDLINE | ID: covidwho-1390020

ABSTRACT

OBJECTIVE: Co-circulation of the two Influenza B lineages hinders forecast of strain to include in trivalent vaccine. Autonomous Communities such as Cantabria continue without supplying tetravalent vaccine. The aim of this study was to analyse epidemiological characteristics of influenza type B in Cantabria (2019-2020 season) as well as to establish the predominant lineage and its relation to the recommended vaccine. METHODS: Retrospective study whereby flu diagnosis and lineage analysis were determined by RT-PCR. RESULTS: All samples belonged to the Victoria lineage. Most prevalent viral co-infection was due to SARS-CoV-2. The population affected by influenza B was mainly paediatric and non-vaccinated patients more frequently required hospital admittance. CONCLUSIONS: Influenza type B has a higher incidence in the paediatric population and type A affects more the adult population. Only 28.8% of patients with Influenza B that presented with some underlying condition or risk factor were vaccinated. This shows the need to increase coverage with tetravalent vaccines in order to reduce the burden of disease associated with the Influenza B virus.


Subject(s)
COVID-19/epidemiology , Influenza B virus , Influenza, Human/epidemiology , Pandemics , SARS-CoV-2 , Adult , COVID-19/virology , Chi-Square Distribution , Child , Coinfection/epidemiology , Coinfection/virology , Epidemics , Female , Hospitalization/statistics & numerical data , Humans , Influenza Vaccines/administration & dosage , Influenza, Human/prevention & control , Influenza, Human/virology , Male , Retrospective Studies , Seasons , Spain/epidemiology , Statistics, Nonparametric
3.
J Glaucoma ; 30(8): 711-717, 2021 08 01.
Article in English | MEDLINE | ID: covidwho-1358502

ABSTRACT

PRECIS: Vascular diseases have been linked to alterations in optic nerve head perfusion. PURPOSE: The main objective was to investigate the changes in peripapillary vessel density (VD) in post coronavirus disease (COVID-19) patients. METHODS: In this prospective pilot exploratory study, patients with COVID-19 that were attended in the Emergency Department of Hospital Clinico San Carlos (Madrid) were included. All patients underwent optic nerve head optical coherence tomography angiography using the Cirrus HD-OCT 500 with AngioPlex OCTA (Zeiss, Dublin, CA) 4 and 12 weeks after diagnosis by positive reverse transcriptase-polymerase chain reaction test from nasopharyngeal swab at the Emergency Department. Sociodemographic data, medical history, disease severity, and laboratory work-up were collected. RESULTS: One hundred and eighty eyes of 90 patients with severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection were included. None of the patients reported visual changes. Severe patients were older, more frequently hispanic, dyslipidemic, and presented lower lymphocytes counts, as well as increased ferritin, D-dimer, fibrinogen, and international normalized ratio levels. No changes in optic nerve head vascularization were observed when both visits were compared. No correlation was found between VD and clinical parameters, disease severity and laboratory work-up. CONCLUSIONS: Changes to peripapillary VD were not observed in patients with COVID-19 in the early months following diagnosis.


Subject(s)
COVID-19 , Optic Disk , Fluorescein Angiography , Humans , Intraocular Pressure , Prospective Studies , Retinal Vessels , SARS-CoV-2 , Tomography, Optical Coherence
4.
Ultrasound Med Biol ; 47(8): 1997-2005, 2021 08.
Article in English | MEDLINE | ID: covidwho-1286382

ABSTRACT

The goal of this review was to systematize the evidence on pulmonary ultrasound (PU) use in diagnosis, monitorization or hospital discharge criteria for patients with coronavirus disease 2019 (COVID-19). Evidence on the use of PU for diagnosis and monitorization of or as hospital discharge criteria for COVID-19 patients confirmed to have COVID-19 by reverse transcription polymerase chain reaction (RT-PCR) between December 1, 2019 and July 5, 2020 was compared with evidence obtained with thoracic radiography (TR), chest computed tomography (CT) and RT-PCR. The type of study, motives for use of PU, population, type of transducer and protocol, results of PU and quantitative or qualitative correlation with TR and/or chest CT and/or RT-PCR were evaluated. A total of 28 articles comprising 418 patients were involved. The average age was 50 y (standard deviation: 25.1 y), and there were 395 adults and 23 children. One hundred forty-three were women, 13 of whom were pregnant. The most frequent result was diffuse, coalescent and confluent B-lines. The plural line was irregular, interrupted or thickened. The presence of subpleural consolidation was noduliform, lobar or multilobar. There was good qualitative correlation between TR and chest CT and a quantitative correlation with chest CT of r = 0.65 (p < 0.001). Forty-four patients were evaluated only with PU. PU is a useful tool for diagnosis and monitorization and as criteria for hospital discharge for patients with COVID-19.


Subject(s)
COVID-19 Testing/methods , COVID-19/diagnosis , Lung/diagnostic imaging , Ultrasonography/methods , Humans , SARS-CoV-2
5.
Clin Chem Lab Med ; 59(7): 1315-1322, 2021 Jun 25.
Article in English | MEDLINE | ID: covidwho-1278216

ABSTRACT

OBJECTIVES: Severe forms of coronavirus disease 2019 (COVID-19) are characterized by an excessive production of inflammatory cytokines. Activated monocytes secrete high levels of cytokines. Human monocytes are divided into three major populations: conventional (CD14posCD16neg), non-classical (CD14dimCD16pos), and intermediate (CD14posCD16pos) monocytes. The aim of this study was to analyze whether the distribution of conventional (CD16neg) and CD16pos monocytes is different in patients with COVID-19 and whether the variations could be predictive of the outcome of the disease. METHODS: We performed a prospective study on 390 consecutive patients referred to the Emergency Unit, with a proven diagnosis of SARS-CoV 2 infection by RT-PCR. Using the CytoDiff™ reagent, an automated routine leukocyte differential, we quantified CD16neg and CD16pos monocytes. RESULTS: In the entire population, median CD16neg and CD16pos monocyte levels (0.398 and 0.054×109/L, respectively) were in the normal range [(0.3-0.7×109/L) and (0.015-0.065×109/L), respectively], but the 35 patients in the intensive care unit (ICU) had a significantly (p<0.001) lower CD16pos monocyte count (0.018 × 109/L) in comparison to the 70 patients who were discharged (0.064 × 109/L) or were hospitalized in conventional units (0.058 × 109/L). By ROC curve analysis, the ratio [absolute neutrophil count/CD16pos monocyte count] was highly discriminant to identify patients requiring ICU hospitalization: with a cut-off 193.1, the sensitivity and the specificity were 74.3 and 81.8%, respectively (area under the curve=0.817). CONCLUSIONS: Quantification of CD16pos monocytes and the ratio [absolute neutrophil count/CD16pos monocyte count] could constitute a marker of the severity of disease in COVID-19 patients.


Subject(s)
COVID-19/diagnosis , Monocytes/cytology , Adult , Aged , Aged, 80 and over , Area Under Curve , Biomarkers/blood , COVID-19/blood , Female , Humans , Intensive Care Units/statistics & numerical data , Leukocyte Count/statistics & numerical data , Male , Middle Aged , Monocytes/classification , Prognosis , Prospective Studies , ROC Curve , SARS-CoV-2 , Young Adult
6.
Clin Epidemiol ; 13: 317-324, 2021.
Article in English | MEDLINE | ID: covidwho-1244938

ABSTRACT

INTRODUCTION: Madrid has been the epicenter of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in Spain. We analyzed our experience with SARS-CoV-2 infected and cancer patients. PATIENTS AND METHODS: We included patients from March 1 to April 30 2020 at Hospital Universitario Puerta de Hierro, Majadahonda, Madrid (Spain). The inclusion criteria were diagnosis of SARS-CoV-2 infection made by reverse transcription polymerase chain reaction (RT-PCR) of nasopharyngeal specimens in cancer patients who were admitted to the hospital due to the need for respiratory support. The exclusion criteria were suspected cases not confirmed. The primary objective was to analyze the mortality rates of patients with cancer, especially those with lung cancer and COVID-19. RESULTS: Overall in-hospital mortality of cancer patients with coronavirus disease 2019 (COVID-19) was 15.2% similar to 12.7% of the global COVID-19 hospitalized population (p=0.615) and greater than that of patients admitted without SARS-CoV-2 infection during the same period 4.3% (p<0.001). Among 653 patients receiving active cancer therapy during the study period, 24 (3.7%) developed COVID-19 and required admission, 4.2% of those receiving chemotherapy, 9.5% immunotherapy and 2.1% targeted therapies. Lung and breast cancer were the most frequent cancer types (26.1%), followed by colorectal cancer (19.6%). Mortality in patients with lung cancer was 25%. The univariate analysis comparing patients who developed a serious event to those who did not showed that the higher Brescia index, CURB-65 scale, lactate dehydrogenase (LDH) or C-reactive protein (CRP) were the risk factors of developing severe complications. CONCLUSION: Patients with cancer, especially lung cancer, and SARS-CoV-2 infection have a worse overall prognosis than the general population.

7.
Anal Chem ; 93(22): 7825-7832, 2021 06 08.
Article in English | MEDLINE | ID: covidwho-1243271

ABSTRACT

COVID-19 first appeared in December of 2019 in Wuhan, China. Since then, it has become a global pandemic. A robust and scalable diagnostics strategy is crucial for containing and monitoring the pandemic. RT-PCR is a known, reliable method for COVID-19 diagnostics, which can differentiate between SARS-CoV-2 and other viruses. However, PCR is location-dependent, time-consuming, and relatively expensive. Thus, there is a need for a more flexible method, which may be produced in an off-the-shelf format and distributed more widely. Paper-based immunoassays can fulfill this function. Here, we present the first steps toward a paper-based test, which can differentiate between different spike proteins of various coronaviruses, SARS-CoV-1, SARS-CoV-2, and CoV-HKU1, with negligible cross-reactivity for HCoV-OC43 and HCoV-229E in a single assay, which takes less than 30 min. Furthermore, our test can distinguish between fractions of the same spike protein. This is done by an altered assay design with four test line locations where each antigen builds a unique, identifiable binding pattern. The effect of several factors, such as running media, immunoprobe concentration, and antigen interference, is considered. We find that running media has a significant effect on the final binding pattern where human saliva provides results while human serum leads to the lowest signal quality.


Subject(s)
COVID-19 , Coronavirus OC43, Human , China , Humans , SARS-CoV-2 , Spike Glycoprotein, Coronavirus
8.
BMJ Open Gastroenterol ; 8(1)2021 05.
Article in English | MEDLINE | ID: covidwho-1236440

ABSTRACT

OBJECTIVE: This study will test the performance of the anal swab PCR test when compared with the nasopharyngeal swab PCR test as a diagnostic tool for COVID-19. DESIGN: An observational descriptive study which included hospitalised suspected, or probable cases of hopitalised COVID-19 patients, conducted in Dr. Cipto Mangunkusumo National Hospital, Ciputra Hospital, Mitra Keluarga Depok Hospital and Mitra Keluarga Kelapa Gading Hospital, Indonesia. Epidemiological, clinical, laboratory and radiology data were obtained. Nasopharyngeal and anal swabs specimens were collected for SARS-CoV-2 RNA detection. RESULTS: We analysed 136 subjects as part of this study. The clinical spectrum of COVID-19 manifesation in this study was typical of hospitalised patients, with 25% classified as mild cases, 14.7% in severe condition and 12.5% of subjects classified as having acute respiratory distress syndrome. When compared with nasopharyngeal swab as the standard specimen for reverse transcription polymerase chain reaction (RT-PCR) detection of SARS-CoV-2 antigen, the sensitivity and specificity of the anal swab was 36.7% and 93.8%, respectively. The positive and negative predictive value were 97.8% and 16.5 %, respectively. The performance of the anal swab remained similar when only the subgroup of patients with gastrointestinal symptoms (n=92, 67.6%) was analysed (sensitivity 40% and specificity 91.7%). Out of all the subjects included in analysis, 67.6% had gastrointestinal symptoms. Similarly, 73.3% of patients in the anal swab-positive group had gastrointestinal symptoms. The two most common gastrointestinal symptoms in the subjects' population were nausea and anorexia. CONCLUSION: Anal swab specimen has low sensitivity (36.7%) but high specificity (93.8%) for detecting SARS-CoV-2 antigen by RT-PCR. Only one additional positive result was found by anal swab among the nasopharyngeal swab-negative group. Anal swab may not be needed as an additional test at the beginning of a patient's diagnostic investigation and nasopharyngeal swab RT-PCR remains as the standard diagnostic test for COVID-19.


Subject(s)
Anal Canal/virology , COVID-19/diagnosis , Gastrointestinal Diseases/virology , Reverse Transcriptase Polymerase Chain Reaction/methods , SARS-CoV-2/genetics , Adult , COVID-19/epidemiology , COVID-19/virology , COVID-19 Testing/methods , Diagnostic Tests, Routine/standards , Diagnostic Tests, Routine/statistics & numerical data , Female , Gastrointestinal Diseases/diagnosis , Hospitalization , Humans , Indonesia/epidemiology , Male , Middle Aged , Nasopharynx/virology , Predictive Value of Tests , Reverse Transcriptase Polymerase Chain Reaction/statistics & numerical data , Sensitivity and Specificity
9.
Elife ; 102021 04 20.
Article in English | MEDLINE | ID: covidwho-1234904

ABSTRACT

Diagnosis of SARS-CoV-2 (COVID-19) requires confirmation by reverse transcription-polymerase chain reaction (RT-PCR). Abbott ID NOW provides fast results but has been criticized for low sensitivity. Here we determine the sensitivity of ID NOW in an ambulatory population presented for testing. The study enrolled 785 symptomatic patients, of whom 21 were positive by both ID NOW and RT-PCR, and 2 only by RT-PCR. All 189 asymptomatic patients tested negative. The positive percent agreement between the ID NOW assay and the RT-PCR assay was 91.3%, and negative percent agreement was 100%. The results from the current study were included into a larger systematic review of literature where at least 20 subjects were simultaneously tested using ID NOW and RT-PCR. The overall sensitivity for ID NOW assay was calculated at 84% (95% confidence interval 55-96%) and had the highest correlation to RT-PCR at viral loads most likely to be associated with transmissible infections.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , Reverse Transcriptase Polymerase Chain Reaction/methods , SARS-CoV-2/isolation & purification , Adult , Female , Genome, Viral , Humans , Male , Middle Aged , Nose/virology , Nucleic Acid Amplification Techniques/methods , Point-of-Care Systems , SARS-CoV-2/genetics , Sensitivity and Specificity , Specimen Handling , Viral Load
10.
Pediatr Res ; 2021 May 18.
Article in English | MEDLINE | ID: covidwho-1233701

ABSTRACT

BACKGROUND: There has been a recent upsurge in the cases of Multisystem inflammatory syndrome in children (MIS-C) associated with Coronavirus disease (COVID-19). We performed a systematic review and meta-analysis on the demographic profile, clinical characteristics, complications, management, and prognosis of this emerging novel entity. METHODS: Using a predefined search strategy incorporating MeSH terms and keywords, all known literature databases were searched up till 10th July 2020. The review was done in accordance with PRISMA guidelines and registered in PROSPERO (CRD4202019757). RESULTS: Of the 862 identified publications, 18 studies comprising 833 patients were included for meta-analysis. The socio-demographic profile showed male predilection (p = 0.0085) with no significant racial predisposition. A higher incidence of gastrointestinal symptoms (603/715, 84.3%), myocarditis (191/309, 61.8%), left ventricular dysfunction (190/422, 45.0%), pericardial (135/436, 31.0%) and neurological symptoms (138/602, 22.9%) was reported. Serological evidence of SARS-CoV-2 had higher sensitivity compared to rtPCR (291/800, 36.4% vs 495/752, 65.8%; p < 0.001). Coronary artery anomaly (CAA) was reported in 117/681 in 9 publications (17.2%). A total of 13 (1.6%) fatalities were reported. CONCLUSION: Clinicians need to be vigilant in identifying the constellation of these symptoms in children with clinical or epidemiologic SARS-CoV-2 infection. Early diagnosis and treatment lead to a favorable outcome. IMPACT: Key message This review analyses the demographic profile, clinical spectrum, management strategies, prognosis, and pathophysiology of MIS-C among children with SARS-CoV-2 infection. The stark differences of MIS-C from Kawasaki disease with respect to demographics and clinical spectrum is addressed. Over-reliance on rtPCR for diagnosis can miss the diagnosis of MIS-C. New addition to existing literature The first systematic review and meta-analysis of published literature on MIS-C associated with COVID-19. IMPACT: The article will serve to spread awareness among the clinicians regarding this emerging novel entity, so that diagnosis can be made early and management can be initiated promptly.

11.
Virusdisease ; 32(2): 187-189, 2021 Jun.
Article in English | MEDLINE | ID: covidwho-1220581

ABSTRACT

In this current pandemic of coronavirus disease 2019 (COVID-19), prompt interventions in terms of early detection and clinical management along with isolation of positive cases is of utmost importance. This helps to limit not only the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections but also the morbidity and mortality associated with it. Different strategies for screening of COVID-19 in containment zones and non-containment areas include testing of symptomatic patients and their contacts in fever clinics, hospital-based testing, testing on demand and population-based screening. The choice of tests like reverse-transcription polymerase chain reaction (RT-PCR), rapid antigen testing (RAT) or antibody test depends upon these strategies and also the turnaround time. Currently, RT-PCR is considered the gold standard for COVID-19 detection. This commentary provides the insights and experiences on COVID-19 diagnosis by RT-PCR. The utility of this test is limited by several false positive, false negative and inconclusive results at early stages of infection, scarcity of reagents and lack of well-equipped labs including trained staff. Moreover, appropriate sample collection and transport, standard laboratory protocols, stringent quality control norms, good quality RNA extraction kits, PCR kits with suitable primers can help in improving accuracy of the test results. A careful assessment of clinical, radiological and molecular findings is required for identifying potential cases of COVID-19.

12.
J Thorac Imaging ; 35(6): 354-360, 2020 Nov 01.
Article in English | MEDLINE | ID: covidwho-1219555

ABSTRACT

The diagnosis of coronavirus disease 2019 (COVID-19) is confirmed by reverse transcription polymerase chain reaction. The utility of chest radiography (CXR) remains an evolving topic of discussion. Current reports of CXR findings related to COVID-19 contain varied terminology as well as various assessments of its sensitivity and specificity. This can lead to a misunderstanding of CXR reports and makes comparison between examinations and research studies challenging. With this need for consistency, we propose language for standardized CXR reporting and severity assessment of persons under investigation for having COVID-19, patients with a confirmed diagnosis of COVID-19, and patients who may have radiographic findings typical or suggestive of COVID-19 when the diagnosis is not suspected clinically. We recommend contacting the referring providers to discuss the likelihood of viral infection when typical or indeterminate features of COVID-19 pneumonia on CXR are present as an incidental finding. In addition, we summarize the currently available literature related to the use of CXR for COVID-19 and discuss the evolving techniques of obtaining CXR in COVID-19-positive patients. The recently published expert consensus statement on reporting chest computed tomography findings related to COVID-19, endorsed by the Radiological Society of North American (RSNA), the Society of Thoracic Radiology (STR), and American College of Radiology (ACR), serves as the framework for our proposal.


Subject(s)
COVID-19/diagnostic imaging , Lung/diagnostic imaging , Radiography, Thoracic/methods , Tomography, X-Ray Computed/methods , Humans , SARS-CoV-2 , Sensitivity and Specificity
13.
Virol Sin ; 35(6): 758-767, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-1217478

ABSTRACT

Reverse transcription-polymerase chain reaction (RT-PCR) is an essential method for specific diagnosis of SARS-CoV-2 infection. Unfortunately, false negative test results are often reported. In this study, we attempted to determine the principal causes leading to false negative results of RT-PCR detection of SARS-CoV-2 RNAs in respiratory tract specimens. Multiple sputum and throat swab specimens from 161 confirmed COVID-19 patients were tested with a commercial fluorescent RT-PCR kit targeting the ORF1ab and N regions of SARS-CoV-2 genome. The RNA level of a cellular housekeeping gene ribonuclease P/MRP subunit p30 (RPP30) in these specimens was also assessed by RT-PCR. Data for a total of 1052 samples were retrospectively re-analyzed and a strong association between positive results in SARS-CoV-2 RNA tests and high level of RPP30 RNA in respiratory tract specimens was revealed. By using the ROC-AUC analysis, we identified Ct cutoff values for RPP30 RT-PCR which predicted false negative results for SARS-CoV-2 RT-PCR with high sensitivity (95.03%-95.26%) and specificity (83.72%-98.55%) for respective combination of specimen type and amplification reaction. Using these Ct cutoff values, false negative results could be reliably identified. Therefore, the presence of cellular materials, likely infected host cells, are essential for correct SARS-CoV-2 RNA detection by RT-PCR in patient specimens. RPP30 could serve as an indicator for cellular content, or a surrogate indicator for specimen quality. In addition, our results demonstrated that false negativity accounted for a vast majority of contradicting results in SARS-CoV-2 RNA test by RT-PCR.


Subject(s)
COVID-19 Testing/methods , COVID-19/diagnosis , RNA, Viral/genetics , SARS-CoV-2/genetics , Autoantigens/genetics , COVID-19/epidemiology , COVID-19/virology , China/epidemiology , Humans , Negative Results , Polyproteins/genetics , RNA, Viral/isolation & purification , Reference Standards , Retrospective Studies , Reverse Transcriptase Polymerase Chain Reaction/methods , Ribonuclease P/genetics , SARS-CoV-2/isolation & purification , Sensitivity and Specificity , Viral Proteins/genetics
14.
Lab Med ; 52(2): e46-e49, 2021 Mar 15.
Article in English | MEDLINE | ID: covidwho-1214639

ABSTRACT

OBJECTIVE: Because of the rapidly emerging SARS-CoV-2 pandemic and its wide public health challenges, rapid diagnosis is essential to decrease the spread. Antigen-based rapid detection tests are available; however, insufficient data about their performance are available. METHODS: The lateral-flow immunochromatographic BIOCREDIT COVID-19 antigen test was evaluated using nasopharyngeal swabs in a viral transport medium from patients with confirmed infection, contacts, and exposed healthcare professionals at Fayoum University Hospital in Egypt. Test performance was determined in comparison to the SARS-CoV-2 real-time reverse-transcription polymerase chain reaction (RT-PCR) test. RESULTS: Three hundred ten specimens from 3 categories-patients with confirmed diagnoses of COVID-19, contacts, and exposed healthcare professionals-were included; 188 specimens were RT-PCR-positive, from which 81 were detected by rapid antigen test. Overall sensitivity was 43.1%. Sensitivity was significantly higher in specimens with high viral loads. CONCLUSION: Poor sensitivity of the BIOCREDIT COVID-19 test does not permit its use for diagnosis, and it can only be used in conjunction with RT-PCR for screening.


Subject(s)
COVID-19 Serological Testing , COVID-19/diagnosis , Immunoassay/statistics & numerical data , Adult , Egypt , Female , Humans , Male
15.
J Clin Med ; 10(9)2021 Apr 21.
Article in English | MEDLINE | ID: covidwho-1201827

ABSTRACT

BACKGROUND: There is much data available concerning the initiation of the immune response after SARS-CoV-2 infection, but long-term data are scarce. METHODS: We thus longitudinally evaluated and compared the total and neutralizing immune response of 61 patients to SARS-CoV-2 infection up to eight months after diagnosis by RT-PCR using several commercial assays. RESULTS: Among the 208 samples tested, the percentage of seropositivity was comparable between assays up to four months after diagnosis and then tended to be more heterogeneous between assays (p < 0.05). The percentage of patients with a neutralizing titer decreased from 82% before two months postdiagnosis to 57% after six months. This decrease appeared to be more marked for patients under 65 years old and those not requiring hospitalization. The percentage of serology reversion at 6 months was from 11% with the WANTAI total assay to over 39% with the ABBOTT IgG assay. The neutralizing antibody titers decreased in parallel with the decrease of total antibody titers, with important heterogeneity between assays. CONCLUSIONS: In conclusion, serological tests show equivalent sensitivity in the first months after the diagnosis of SARS-CoV-2 infection, but their performance later, postinfection, must be considered when interpreting the results.

16.
Eur J Epidemiol ; 36(7): 727-734, 2021 Jul.
Article in English | MEDLINE | ID: covidwho-1196603

ABSTRACT

The first local spread of COVID-19 in Israel was detected in March 2020. Due to the diversity in clinical presentations of COVID-19, diagnosis by RT-PCR alone might miss patients with mild or no symptoms. Serology testing may better evaluate the actual magnitude of the spread of infection in the population. This is the first nationwide seroprevalence study conducted in Israel. It is one of the most widespread to be conducted thus far, and the largest per-country population size. The survey was conducted between June 28 and September 14, 2020 and included 54,357 patients who arrived at the Health Maintenance Organizations to undergo a blood test for any reason. A patient was considered seropositive after two consecutive positive results with two different kits (Abbott and DiaSorin).The overall seroprevalence was 3.8% (95%CI 3.7-4.0), males higher than females [4.9% (95%CI 4.6-5.2) vs. 3.1% (95%CI 2.9-3.3) respectively]. Adolescents had the highest prevalence [7.8% (95%CI 7.0-8.6)] compared to other age groups. Participants who had undergone RT-PCR testing had a tenfold higher risk to be seropositive. The prevalence-to-incidence ratio was 4.5-15.7. Serology testing is an important complimentary tool for assessing the actual magnitude of infection and thus essential for implementing policy measures to control the pandemic. A positive serology test result was recently accepted in Israel as being sufficient to define recovery, with possible far-reaching consequences, such as the deploying of employees to ensure the maintenance of a functional economy.


Subject(s)
Antibodies, Viral/blood , COVID-19 Serological Testing , COVID-19/epidemiology , SARS-CoV-2/immunology , Adolescent , Adult , Aged , Aged, 80 and over , Biomarkers/blood , COVID-19/diagnosis , COVID-19/virology , COVID-19 Nucleic Acid Testing , COVID-19 Serological Testing/methods , Child , Child, Preschool , Female , Humans , Incidence , Infant , Infant, Newborn , Israel/epidemiology , Male , Middle Aged , Prevalence , Seroepidemiologic Studies , Young Adult
17.
Microchem J ; 164: 106094, 2021 May.
Article in English | MEDLINE | ID: covidwho-1195380

ABSTRACT

Undoubtedly, the coronavirus pandemic is one of the most influential events not only in medicine but also in the economic field in the world. Rapid transmission and high mortality rates, as well as prolonged and asymptomatic communal periods, are the most important reasons for the global panic due to coronavirus. Since coronavirus treatment and specific vaccines are not yet available, early detection of the virus is critical. A rapid and accurate diagnosis can play a crucial role in the treatment and control of the COVID 19 disease. Serological, ELISA, and molecular-based tests, including PCR and RT-PCR, are among the most important routine methods for detecting coronaviruses. False-positive/negative results, low sensitivity and specificity, and the need for advanced equipment are among the disadvantages and problems of routine methods. To eliminate the drawbacks of routine methods, new technologies are being developed. Biosensors are one of the most important ones. This paper is a summary of the up-to-date states of innovative bio-sensing tools for the ultrasensitive detection of coronaviruses (COVID 19) with encouraging uses for future challenges in disease diagnosis.

18.
Lancet Infect Dis ; 21(9): 1233-1245, 2021 09.
Article in English | MEDLINE | ID: covidwho-1180122

ABSTRACT

BACKGROUND: The comparative performance of different clinical sampling methods for diagnosis of SARS-CoV-2 infection by RT-PCR among populations with suspected infection remains unclear. This meta-analysis aims to systematically compare the diagnostic performance of different clinical specimen collection methods. METHODS: In this systematic review and meta-analysis, we systematically searched PubMed, Embase, MEDLINE, Web of Science, medRxiv, bioRxiv, SSRN, and Research Square from Jan 1, 2000, to Nov 16, 2020. We included original clinical studies that examined the performance of nasopharyngeal swabs and any additional respiratory specimens for the diagnosis of SARS-CoV-2 infection among individuals presenting in ambulatory care. Studies without data on paired samples, or those that only examined different samples from confirmed SARS-CoV-2 cases were not useful for examining diagnostic performance of a test and were excluded. Diagnostic performance, including sensitivity, specificity, positive predictive value, and negative predictive value, was examined using random effects models and double arcsine transformation. FINDINGS: Of the 5577 studies identified in our search, 23 studies including 7973 participants with 16 762 respiratory samples were included. Respiratory specimens examined in these studies included 7973 nasopharyngeal swabs, 1622 nasal swabs, 6110 saliva samples, 338 throat swabs, and 719 pooled nasal and throat swabs. Using nasopharyngeal swabs as the gold standard, pooled nasal and throat swabs gave the highest sensitivity of 97% (95% CI 93-100), whereas lower sensitivities were achieved by saliva (85%, 75-93) and nasal swabs (86%, 77-93) and a much lower sensitivity by throat swabs (68%, 35-94). A comparably high positive predictive value was obtained by pooled nasal and throat (97%, 90-100) and nasal swabs (96%, 87-100) and a slightly lower positive predictive value by saliva (93%, 88-97). Throat swabs have the lowest positive predictive value of 75% (95% CI 45-96). Comparably high specificities (range 97-99%) and negative predictive value (range 95-99%) were observed among different clinical specimens. Comparison between health-care-worker collection and self-collection for pooled nasal and throat swabs and nasal swabs showed comparable diagnostic performance. No significant heterogeneity was observed in the analysis of pooled nasal and throat swabs and throat swabs, whereas moderate to substantial heterogeneity (I2 ≥30%) was observed in studies on saliva and nasal swabs. INTERPRETATION: Our review suggests that, compared with the gold standard of nasopharyngeal swabs, pooled nasal and throat swabs offered the best diagnostic performance of the alternative sampling approaches for diagnosis of SARS-CoV-2 infection in ambulatory care. Saliva and nasal swabs gave comparable and very good diagnostic performance and are clinically acceptable alternative specimen collection methods. Throat swabs gave a much lower sensitivity and positive predictive value and should not be recommended. Self-collection for pooled nasal and throat swabs and nasal swabs was not associated with any significant impairment of diagnostic accuracy. Our results also provide a useful reference framework for the proper interpretation of SARS-CoV-2 testing results using different clinical specimens. FUNDING: Hong Kong Research Grants Council.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , SARS-CoV-2 , Humans , Nasopharynx/virology , Oropharynx/virology , Pharynx/virology , Predictive Value of Tests , Saliva/virology , Sensitivity and Specificity , Specimen Handling/methods
19.
Ann Clin Biochem ; 58(4): 368-376, 2021 07.
Article in English | MEDLINE | ID: covidwho-1175245

ABSTRACT

BACKGROUND: Quantitative antibody tests are expected to be useful in diagnostics of COVID-19 and investigation of herd immunity against SARS-CoV-2. To make it proper to perform them, understanding of the immunological aspects is critically important. The present study aimed to assess humoral responses in COVID-19 using various quantitative antibody tests. METHODS: Four quantitative antibody tests that are different in targeted antigens, detectable immunoglobulin classes and avidity were used. Diagnosis was confirmed by RT-PCR for SARS-CoV-2 detection. Antibody titres of 117 samples collected from 24 COVID-19 patients and 23 non-COVID-19 patients were measured to evaluate correlations between different tests. For 24 COVID-19 patients, antibody titres measured at various time points after the onset or the RT-PCR diagnosis were subjected to assessment of humoral responses. RESULTS: Correlations between tests were observed to some degree, although there were discrepancies putatively due to differences in measurement principle. Seronegative COVID-19 was diagnosed for some patients, in whom antibody titres were less than the cut-off value in each test throughout the time courses. IgG seroconversion without prior IgM seroconversion most frequently occurred, while predominance of IgM responses over IgG responses was observed in some severe cases. Viral burdens estimated according to threshold cycle values at the RT-PCR seemed to impact antibody responses. CONCLUSIONS: The results provide insights into the nature of humoral responses to SARS-CoV-2 and diagnostic performance of antibody tests.


Subject(s)
Antibodies, Viral , COVID-19 Nucleic Acid Testing , COVID-19 Serological Testing , COVID-19 , Immunity, Humoral , Immunoglobulin G , Immunoglobulin M , SARS-CoV-2 , Antibodies, Viral/blood , Antibodies, Viral/immunology , COVID-19/blood , COVID-19/diagnosis , COVID-19/immunology , Female , Humans , Immunoglobulin G/blood , Immunoglobulin G/immunology , Immunoglobulin M/blood , Immunoglobulin M/immunology , Male , SARS-CoV-2/immunology , SARS-CoV-2/metabolism
20.
Expert Rev Clin Immunol ; 17(6): 573-599, 2021 06.
Article in English | MEDLINE | ID: covidwho-1160272

ABSTRACT

Introduction: The gold standard for diagnosis of coronavirus disease 2019 (COVID-19) is detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by reverse transcription polymerase chain reaction (RT-PCR), which is expensive, time-consuming and may result in false-negative results. Serological tests can be employed for RT-PCR negative patients, contact tracing, determining the probability of protection against re-infection, and seroepidemiological studies.Areas covered: The main methodologies of serology-based tests for the detection of SARS-CoV-2 including enzyme-linked immunosorbent assays (ELISAs), chemiluminescent immunoassays (CLIAs) and lateral flow immunoassays (LFIAs) were reviewed and their diagnostic performances were compared. Herein, a literature review on the databases of PubMed, Scopus and Google Scholar between January 1, 2020 and June 30, 2020 based on the main serological methods for COVID-19 detection with the focus on comparative experiments was performed. The review was updated on December 31, 2020.Expert opinion: Serology testing could be considered as a part of diagnostic panel two-week post symptom onset. Higher sensitivity for serology-based tests could be achieved by determining combined IgG/IgM titers. Furthermore, higher sensitive serological test detecting neutralization antibody could be developed by targeting spike (S) antigen. It was also demonstrated that the sensitivity of ELISA/CLIA-based methods are higher than LFIA devices.


Subject(s)
Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19 Serological Testing , COVID-19/diagnosis , Immunoglobulin G/blood , Immunoglobulin M/blood , SARS-CoV-2/immunology , Biomarkers/blood , COVID-19/immunology , COVID-19/virology , Enzyme-Linked Immunosorbent Assay , Host-Pathogen Interactions , Humans , Luminescent Measurements , Predictive Value of Tests , Reproducibility of Results
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