ABSTRACT
Introduction: The Coronavirus Disease 2019 (COVID-19) pandemic has affected the entire world. The need of timely detection of the virus has been of prime importance and the efforts to develop sensitive, specific, rapid, portable and cost effective diagnostic methods promoted the indigenous development of TrueNat testing for viral load in COVID-19 detection which had been previously designed for detection of Tuberculosis and other infectious organisms. Aim: To see the importance of TrueNat testing among symptomatic and asymptomatic cases in different age groups and gender. Materials and Methods: In this retrospective study conducted in the Department of Microbiology, Autonomous State Medical College and SNM Hospital, Firozabad, Uttar Pradesh, India, from June 2020 - May 2021, a total of 4,659 samples were collected from patients (Influenza Like Illness (ILI), Severe Acute Respiratory Illness (SARI), symptomatic, asymptomatic, those seeking hospitalisation, emergency), contacts and travellers and were subjected to testing by TrueNat (Molbio Quattro). 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 symptoms of patients were associated with the Cycle threshold (Ct) values of the Envelope (E) gene and the RNA-dependent RNA polymerase gene (RdRp) gene. The Chi-square test was done to test the statistical significance of association of symptomatic patients with the outcome of the test. Results: The maximum number of positive cases were found in the people 20-39 years (p-value <0.05). The least positivity was found in the higher (80 years) and lower (below 9 years) age groups. The positivity rates had no significant impact on the gender. The percentage positivity as detected by TrueNat testing was 3.3% and maximum positive patients were found in the group having symptoms <7 days (p<0.05). On association of the Ct values of E gene and RdRp gene with the symptoms it was found that 28.1% and 27.2% of the patients were in the high Ct value group. Conclusion: TrueNat was found to be a portable and easy to perform test which did not require special laboratory set up. The use of Viral Lysis Medium (VLM) reduced the time of RNA extraction which not only rendered it safer to perform but expedited the results.
ABSTRACT
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, Rapid Antigen Testing (RAT) is very helpful in detecting the virus. Aim: To discuss the importance of rapid 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-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 (p-value <0.05) followed by 20-29 years. The least number of positive cases (six) was found in the higher (90 years) and lower (below 9 years) age groups. No significant impact was found on the positivity rates on the basis of gender. The percentage positivity as detected by rapid antigen was 2% 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 set up. 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.