From Bench to Bedside: A Retrospective Study on the Utility of Rapid Antigen Testing for Coronavirus Disease from Firozabad, Uttar Pradesh, India
Dr. Lekha Tuli,
Associate Professor, Department of Microbiology, Autonomous State Medical College, Firozabad-283203, Uttar Pradesh, India.
Introduction: Ever since the Coronavirus Disease-2019 (COVID-19) pandemic hit, there have been constant efforts to develop rapid, sensitive and specific diagnostic methods to detect the virus in order to curb the further spread of the disease. There is an array of tests available for the detection of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). Time being a very crucial factor and Rapid Antigen Testing (RAT) is very helpful in detecting the virus.
Aim: To discuss the importance of rapid antigen testing among symptomatic and asymptomatic cases in different age groups and gender with association to infection.
Materials and Methods: This retrospective study was conducted in Department of Microbiology, Autonomous State Medical College and SNM Hospital, Firozabad, Uttar Pradesh, India, from April 2020 to August 2021. A total of 16,258 samples were collected from symptomatic patients having Influenza Like Illness (ILI), Severe Acute Respiratory Illness (SARI), those seeking hospitalisation, contacts (symptomatic and asymptomatic) and travellers were subjected to antigen detection by the Standard Q COVID-19 antigen kit following proper precautions. The cases were divided into Group A of patients who presented with symptoms ≤7 days, Group B of patients who presented with signs and symptoms >7 days and group C comprised of asymptomatic patients. The Chi-square test was done to test the statistical significance of association of symptomatic patients with outcome of the antigen test.
Results: Of the total 16,258 samples tested, the maximum number of positive cases were found in the age group 30-39 years followed by 20-29 years. The least number of positive cases were found in extreme age group, i.e., six cases in >90 years and no case was found in below 9 years. No significant impact was found on the positivity rates on the basis of gender. The percentage positivity as detected by rapid antigen was 2.1% and maximum patients were found in the group having symptoms ≤7 days (p<0.05).
Conclusion: Rapid Antigen Detection Test (RADT) for SARS-CoV-2 is a simple, portable, fast and easy to perform test. It could be easily used in rural areas as it does not require special laboratory setup. It could be used for mass testing and helped as a good epidemiological tool. However, few symptomatic cases which could not be detected by rapid testing had to be cross checked with Real Time-Reverse Transcriptase Polymerase Chain Reaction (RT-PCR). Thus, when used in conjunction with molecular methods, the sensitivity of the test increased.