SARS-COV-2 antibody testing Versus Nasopharyngeal and Oropharyngeal swab Sample Polymerase Chain Reaction for Diagnosis of Coronavirus Disease 2019 (COVID-19) in Egyptian Patient. A Comparative study

Abstract

Background: SARS-CoV-2 identification via Real-time polymerase chain reaction (RT-PCR) testing considered the current standard for the diagnosis of infection, but itsutilization for large-scale screening is limited. Serological immunoglobulin M (IgM)/IgG testing has been proposed as a useful tool for detecting SARS-CoV-2 exposure, Objectives; to assess the diagnostic value of SARS-COV-2 IgM and IgG in early diagnosis of patient with COVID-19 versus viral RNA detection by PCR and to Investigate the sensitivity of nasopharyngeal swabs versus oropharyngeal samples for early detection of SARS-COV-2. Methodology: This study was carried on 200 COVID-19 PCR positive cases divided into two groups as (Group I). In addition to 200 apparently healthy individuals (Negative PCR) as a control group (Group II) obtained From Ministry of Health Hospitals after getting approval. All patients were subjected to: clinical examination, lab investigation including; SARS-COV-2 IgM and IgG testing, SARS-COV-2 PCR test from nasopharyngeal and Oropharyngeal swabs samples, Results; Regarding IgM after 10 days, It was positive in 77 (38.5 %) of patients with Positive PCR while no one was positive in patients with negative PCR with sensitivity of 38.5 % , Specificity 100.0 %, and accuracy 69.25 %, Nasopharyngeal Swabs (NPS) had significantly higher SARS-CoV-2 detection rate, sensitivity, and viral load than Oropharyngeal Swabs. NPS could reduce droplets production during swabs. Conclusion: NPS should be recommended for diagnosing COVID-19 and monitoring SARS-CoV-2 load. Also, our study analyzed the clinical performance of the rapid serological test and confirmed the test's limited applicability for the diagnosis of SARS-CoV-2 infection.