RT- PCR Testing of Nasopharyngeal Samples for Diagnosis of SARS-CoV-2: Between Justification and Overestimation, a Multi-Center International Study
23 Pages Posted: 23 Feb 2022
Abstract
Background: It has been found that patients recovered from COVID 19 may still test Reverse Transcriptase- Polymerase Chain Reaction (RT- PCR) positive without being infectious, reasons are unclear. The occurrence of false negative results of RT- PCR interferes with proper diagnosis. Objectives of that work were to determine factors associated with persistently detectable SARS-CoV-2 RNA among recovered hospitalized patients and to determine incidence of false negative RT- CPR results and associated factors.
Methods: Relevant data were collected from 482 COVID 19 patients hospitalized in six referral centers from four countries.
Results: The median duration of RT- PCR conversion to negative was 20 days. Out of 482 studied patients, 8.7% tested positive after more than 4 weeks and were considered prolonged convertor. Binary logistic regression analysis revealed headache to be an independent risk factor for short conversion time while fever, hypertension, chronic obstructive pulmonary disease (COPD), lymphopenia, elevated erythrocyte sedimentation rate (ESR), number of lobes affected and bilateralism were independent risk factors for prolonged positivity. Eighteen patients had initial negative results then turned positive after 48 hours. Associated factors and outcome were identified.
Conclusion: Results might help in more understanding of COVID-19 pathology so, providing optimal patient management.
Note:
Funding: None to declare.
Declaration of Interests: We have no conflicts of interest to disclose.
Ethics Approval Statement: The study has been approved by the Institutional Review Board (IRB) of the Faculty of Medicine, Port Said University, Port Said, Egypt.
Keywords: Key words: RT- PCR, conversion time, COVID 19, false negative
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