Compersion of Sensitivity and Specificity of Sars COV-2 Rapid Antigen Test with RT-PCR

Background: To diagnose SARS-CoV2 highly sensitive and specific test is required to reduce cost-effect and turnaround time in resource constrained setting. Current study was design to evaluate the sensitivity and specificity of the Rapid antigen test in compression with gold standard RT-PCR. Material and methods: It was comparative cross sectional study conducted at Hayat Medical Complex hospital Peshawar Pakistan within duration of six month (February-July, 2021). All those patients who were suspecting for covid-19 infection regardless of their age and gender were included. Patients, who were unwilling to give data were excluded. Total eighty samples were collected to compare Rapid antigen test with RT-PCR. Statistical tool (SPSS 22) was used for Independent T-test and crossable. Result: In 40 RT-PCR positive sample 34 were true positive by RAT and 6 samples were false negative. While in total 40 RT-PCR negative samples 38 were true negative by RAT and 2 were undetermined. The overall sensitivity of the RAT was 85% (CI; 95%) and specificity was 100% (CI; 95%) and value of independent T test were t (39%) = -14.866, p=0.001. Conclusion: In current study, 6 samples were false negative by Rapid antigen test with mean CT value of 27(viral load 29692 copies/ml). The sensitivity of RAT is dependent on CT value of RT-PCR (viral load) it had better detect viral antigen with CT value < 23 (samples having viral load ≥ 50x103). Hence Rapid antigen test show higher specificity with lower value of sensitivity and recommended as screening test not as diagnostic test. Keyword: SARS COV-2, RT-PCR, Rapid Antigen Test, COVID-19