Rapid Serological Test for COVID-19, One-Step-COVID-2019: Accuracy and Implications for Pandemic Control

Background: Accurate and rapid testing for COVID-19 is critical for effective disease management and control. The One-Step-COVID-2019-Test was developed as a rapid serological test to detect antibodies against SARS-CoV-2. Objective: To estimate the accuracy of the rapid serological test for COVID-19 using One-Step-COVID-2019. Methods: We conducted a population-based serological survey with a stratified sampling of 593 adults between October and December 2020, prior to mass vaccination and during a period of limited availability of rapid tests. Participants provided 7.5 mL of serum, which was tested using the One-Step-COVID-2019-Test for IgM-IgG antibodies without distinction, as well as an in-house ELISA for IgG against the spike protein. Statistical analysis accounted for sampling weights, with accuracy assessed through sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), Youden index, and kappa coefficient, using ELISA as the reference standard. McNemar’s test identified significant differences between the test results. Results: The ELISA-based prevalence of infection was 11.1%. The One-Step-COVID-2019-Test showed low sensitivity (27.0–30.8%) but high specificity (89.9–96.6%), with poor agreement (kappa: 0.290–0.337), particularly among asymptomatic individuals. Conclusions: The One-Step-COVID-2019 rapid test for COVID-19 demonstrated inadequate performance, characterized by low sensitivity and poor reliability, making it unsuitable for effective serological surveillance.