Practical Diagnostic Accuracy of Nasopharyngeal Swab Testing for Novel Coronavirus Disease 2019 (COVID-19) (original) (raw)
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Infectious Diseases Now, 2021
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Nasopharyngeal Specimen Collection from Suspected COVID-19 Cases, Making the Procedure Safe
PAFMJ, 2021
Objective: To comparison was made between standard (control group) nasopharyngeal sample collection technique for RTPCR and modified technique and the outcome was compared in terms of the proportion of positive results of Rt-PCR tests. Study Design: Double blinded randomized clinical trial. Place and Duration of Study: Pakistan Naval Ship Shifa Hospital Karachi Pakistan, from June and July 2020. Methodology: This study was a newly developed modified technique for nasopharyngeal sampling for RT-PCR tests of COVID-19 suspects. Target population included all patients who developed COVID-19 related symptoms and/or also had history of recent travel or closed contact with Covid-19 patients. Total 1500 nasopharyngeal PCR tests were done by a team of trained technicians. Systemetic probability sampling technique was utilized. Subjects were divided into two groups by using even and odd serial numbers. Proportion of positive test results were compared between two groups by using chi square te...
Pakistan BioMedical Journal
Objective:To Determine the Specificity, Accuracy and Sensitivity of HRCT in Diagnosis of Covi-19. Methods: Prospective cohort study was done with 181 participants who were suspected for COVID-19 infection and were followed to evaluate PCR and HRCT reporting in patients with clinical symptoms. Results: 86.8% of patients had a dry cough, followed most commonly with shortness of breath. 65 (35.9%) of patients had ground-glass opacities of haze on HRCT followed by 47 (26 %). who had consolidations present. 147 (81.2)patients had a positive PCR whereas 34 (18.7%) was negative had an HRCT that was suggestive of having COVID-19 pneumonia. Conclusion:In conclusion clinical symptomatology, HRCT findings and PCR all should be used in a triple examination. It is concluded that a positive PCR test is very specific and used to make diagnosis for Covid-19. CT has a higher sensitivity but a lower specificity, thus helping with disease diagnosis and therapy.
Predictive Factors for a New Positive Nasopharyngeal Swab Among Patients Recovered From COVID-19
American Journal of Preventive Medicine, 2021
on behalf of Gemelli Against COVID-19 Post-Acute Care Team Introduction: As an emerging infectious disease, the clinical and virologic course of COVID-19 requires better investigation. The aim of this study is to identify the potential risk factors associated with persistent positive nasopharyngeal swab real-time reverse transcription-polymerase chain reaction tests in a large sample of patients who recovered from COVID-19. Methods: After the acute phase of SARS-CoV-2 epidemic infection, the Fondazione Policlinico A. Gemelli IRCSS of Rome established a post-acute care service for patients discharged from the hospital and recovered from COVID-19. Between April 21 and May 21, 2020, a total of 137 individuals who officially recovered from COVID-19 were enrolled in this study. All patients were tested for the SARS-CoV-2 virus with nucleic acid RT-PCR tests. Analysis was conducted in June 2020. Results: Of the 131 patients who repeated the nasopharyngeal swab, 22 patients (16.7%) tested positive again. Some symptoms such as fatigue (51%), dyspnea (44%), and coughing (17%) were still present in a significant percentage of the patients, with no difference between patients with a negative test and those who tested positive. The likelihood of testing positive for SARS-CoV-2 infection was significantly higher among participants with persistent sore throat (prevalence ratio=6.50, 95% CI=1.38, 30.6) and symptoms of rhinitis (prevalence ratio=3.72, 95% CI=1.10, 12.5). Conclusions: This study is the first to provide a given rate of patients (16.7%) who test positive on RT-PCR test for SARS-CoV-2 nucleic acid after recovering from COVID-19. These findings suggest that a significant proportion of patients who have recovered from COVID-19 still could be potential carriers of the virus. In particular, if patients continue to have symptoms related to COVID-19, such as sore throat and rhinitis, it is reasonable to be cautious by avoiding close contact, wearing a face mask, and possibly repeating a nasopharyngeal swab.
Archives of Biotechnology and Biomedicine
SARS-CoV-2 is the virus associated with the disease called COVID-19 and become a global pandemic. The only way to prevent its severe scenarios is through timely and rapid testing. In comparison to more time taking gold-standard RT-PCR testing, rapid diagnostic kits are used. For better prevention and diagnosis of SARS-CoV-2, the analysis of rapid diagnostic kits' accuracy and specificity is necessary. This study is meant to assess and examine the viability, responsiveness, and explicitness of quick antigen distinguishing nasopharyngeal swabs (NPS), and saliva-based units. The study was conducted on 200 suspected COVID-19 patients from Islamabad, 100 of which were RT-PCR positive while 100 were RT-PCR negative. For the analysis of Rapid diagnostic COVID-19 kits (RDT), nasopharyngeal swabs (NPS) and saliva samples were taken from the RT-PCR positive and negative patients. Among 100 RT-PCR positive patients, 62% were males (19 - 91 years), 34% were females (20 - 78 years) and 4% we...
Clinical and Experimental Health Sciences
Objective: The distinction between COVID-19 and other respiratory infections can be difficult during the flu and winter seasons. The aim of this study is to detect bacterial/viral microorganisms in nasopharyngeal swab samples and to evaluate routine laboratory results of patients with PCR (-) but suspected covid 19. Methods: Between 1 July 2021 and 31 December 2021, 78 patients who were hospitalized and followed up in the suspected Covid service were included in the study. The patients were divided into two groups as those with and without growth on the respiratory panel. Laboratory, demographic and radiological data were compared between groups. Results: C-reactive protein (CRP) and ferritin levels were found to be statistically significantly higher in the group with growth on the respiratory panel compared to the group without growth (p= .05, p= .041, respectively). Reproduction was detected in nasopharyngeal swab samples taken in 56.4% of the patients. More than half of the patie...
2021
Background: COVID-19 is a severe respiratory disease, started in China. For diagnosis, we need swabs from different regions of respiratory tract. Nasopharyngeal swab is the preferred method. Rt-PCR for Corona virus is the gold standard lab test for diagnosis. Objective: To determine frequency of positive PCR tests and complications in total number of nasopharyngeal samples taken at ENT department of Allied Hospital, Faisalabad Pakistan. Study Design: Descriptive cross-sectional study. Settings: ENT department, Allied Hospital, Faisalabad Pakistan. Duration: 1st May 2020 to 31st August 2020. Methodology: Nasopharyngeal swabs of suspected cases, their contacts, and healthcare workers were taken at ENT department of Allied Hospital. All samples were sent to BSL-LAB. The complication related to procedure were also noted. The result was labelled as detected and non-detected. Results: Total sample taken were 2909 out of which 627 (22%) cases were positive for Corona virus while 2282 (78%)...
Iranian Journal of Pathology, 2020
Background & Objective: A simple approach to prevent close contact in healthcare settings during the COVID-19 outbreak is to train patients to collect their own nasopharyngeal and oropharyngeal swabs and deliver them to medical laboratories to have them processed. The aim of our study was to compare lab technician- with patient- collected oropharyngeal and nasopharyngeal samples for detection of the coronavirus disease 2019 (COVID 19) using rapid real-time polymerase chain reaction (rRT-PCR). Methods: Fifty adult patients with flu-like symptoms and radiologic findings compatible with atypical pneumonia who were admitted to the infectious diseases ward of Imam Khomeini Hospital Complex, Tehran, Iran, with a clinical diagnosis of COVID-19 from February 28 to April 27 of 2020 were randomly selected and entered in our study. Two sets of naso- and oropharyngeal swabs were collected, one set by a lab technician and the other by the patients, and the COVID-19 rRT-PCR test was performed. Results: Of 50 selected cases, in seven patients all collected naso- and oropharyngeal swabs tested positive, and in 22 patients all samples tested negative for COVID-19 in rRT-PCR. Discrepancies between rRT-PCR results of lab technician- and patient-collected swabs were observed in 12 nasopharyngeal and 13 oropharyngeal specimens. Positive lab technician-collected and negative patient-collected samples were observed in 10 and 5 nasopharyngeal and oropharyngeal specimens, respectively. Negative lab technician-collected and positive patient-collected samples were observed in two and seven nasopharyngeal and oropharyngeal specimens, respectively. The overall percentage of agreement among both nasopharyngeal and oropharyngeal swabs taken by a lab technician and patients was 76% with a kappa value of 0.49 (p =0.001). Conclusion: Based on our findings, lab technician-collected naso- and oropharyngeal swabs cannot be replaced by patient-collected ones with regard to COVID-19 rRT-PCR.
Diagnostics
Background: The diagnosis of Coronavirus disease 2019 (COVID-19) relies on the positivity of nasopharyngeal swab. However, a significant percentage of symptomatic patients may test negative. We evaluated the reliability of COVID-19 diagnosis made by radiologists and clinicians and its accuracy versus serology in a sample of patients hospitalized for suspected COVID-19 with multiple negative swabs. Methods: Admission chest CT-scans and clinical records of swab-negative patients, treated according to the COVID-19 protocol or deceased during hospitalization, were retrospectively evaluated by two radiologists and two clinicians, respectively. Results: Of 254 patients, 169 swab-confirmed cases and one patient without chest CT-scan were excluded. A total of 84 patients were eligible for the reliability study. Of these, 21 patients died during hospitalization; the remaining 63 underwent serological testing and were eligible for the accuracy evaluation. Of the 63, 26 patients showed anti-Sa...
JOURNAL OF CLINICAL AND DIAGNOSTIC RESEARCH, 2022
Introduction: Real-time Reverse Transcription-Polymerase Chain Reaction (RT-PCR) can be considered to be the gold standard for diagnosis of Coronavirus Disease-2019 (COVID- 19). Though it is highly accurate but has some limitations in terms of its use, which means that Rapid Antigen Tests (RAT) can support COVID-19 mitigation efforts. Aim: To estimate sensitivity, specificity and degree of agreement of STANDARD Q COVID-19 Antigen Detection Kit in comparison to real-time quantitative RT-PCR (qRT-PCR). Materials and Methods: This cross-sectional study was conducted at Government Medical College, Srinagar, Jammu and Kashmir, India, in April 2021. Socio-demographic and clinical information was collected on a pretested schedule after which two consecutive nasopharyngeal swabs were collected from each subject. One sample was tested using the STANDARD Q COVID-19 antigen test and the other was tested using qRT-PCR. Sensitivity and specificity were calculated using standard formulas. Cohen’s...