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Bilal Iqbal
Kulsoom Bahadur
Munir Hussain
Mirza Muhammad Dawood
Muhammad Umar Farooq


Objective: To determine sensitivity and specificity of Roche SARs-cov-2 antibodies assay using real time poly-marase chain reaction (RT-PCR) Covid-19 as standard in Pakistani population.

Methodology: It was a cross-sectional study conducted in Rehman Medical Institute Peshawar from 1st January 2021 till 15th February 2021. This study include 192 suspected Covid-19 patients. Serum samples set consisted of 122 symptomatic RT-PCR positive patients and 70 negative RT-PCR were used for qualitative detection of Antibodies (CoVID-19 IgG, IgM). Overall and period wise (Post RT-PCR) diagnostic accuracy was determined by comparing results of antibodies assay to Rt-PCR. Chi square test was applied to assess the correlation between post-PCR duration and Anti-SARS-Cov-2. A p-value of <0.05 was considered significant.

Results: On post-PCR duration and Anti-SARS-Cov-2 analysis, it was evident that the sensitivity of detection increased steadily with increase in duration after viral detection reaching a value of 94.5% after 20 days. Overall sensitivity was 86.9% with PPV of 97.3%. There was a significant level (X2= 6.846, p =.033) of correlation be­tween detection probability of Antibodies and post-PCR duration at 95% Cl. Anti-SARS-Cov-2 showed a specificity of 95.7% and a NPV of 81.7%.

Conclusion: Our study demonstrated that in middle and later stages of disease antibodies to SARS-CoV-2 can be detected. This testing strategy can be utilized complementary to molecular-based testing of CoVID-19 diagnosis. Also, this can help in determining the seroprevalence of CoVID-19 in the community.

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Iqbal B, Bahadur K, Hussain M, Dawood MM, Farooq MU. ESTIMATING SENSITIVITY AND SPECIFICITY OF COVID 19 ANTIBODIES ASSAY POST RT-PCR TESTING. J Postgrad Med Inst [Internet]. 2021 Sep. 30 [cited 2022 May 21];35(3):148-51. Available from:
Original Article


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