Evaluation of SARS-CoV2 antibody Rapid Diagnostic Test kits (RDTs) Innovita® and Real Time-Polymerase Chain Reaction (Rt-PCR) for COVID-19 infection diagnosis in Kaduna State, Nigeria.

Abstract

Background: The Real-Time Polymerase Chain Reaction (Rt-PCR) is the gold standard diagnostic test for SARS-CoV-2, however, there are several invalidated antibody-based tests available for community screening. This study compared the performance of the SARS-CoV-2 antibody test kits and Rt-PCR in the diagnosis and surveillance of COVID-19 infection. Methodology: The study was conducted at the Infectious diseases control center (IDCC), Kaduna and Hamdala Motel isolation center, of Kaduna State, using a cross-sectional study design. The sample size, of 521 was achieved by the convenience sampling method over a period of three months. Venous blood samples, collected from consenting clients and patients were analyzed for SARS-CoV-2, using the kit by Innovita® Biological Technology CO., LTD China. Oral/nasopharyngeal swabs were collected and analyzed using the Rt-PCR. Data analysis was carried out using the SPSS version 23. Proportions were compared using Chi-square tests for proportions. The level of statistical significance was set at p ≤ 0.05. Result: Our study revealed low sensitivity for both IgM (14.4%) and IgG (15.6%), using the RDT antibody kits, with the specificity of 92.9% and 98.6% for IgM and IgG. Using PCR-positive cases as true positives, the accuracy of the test was 67.8% and 72.0% for IgM and IgG, respectively. The positive and negative predictive values for IgM were 48.9% and 69.7%. For IgG, the corresponding values were 83.9% and 71.2%. Conclusion: The SARS-CoV-2 Innovita® RDT kit is far from ideal as a tool for the rapid seroprevalence survey of Covid-19 with its low sensitivity. More efforts are urgently required to access standard diagnostic kits, with a high sensitivity/specificity index when compared with the gold standard, for community screening, especially in the regions not easily accessible due to a number of reasons.