Burden of Severe Acute Respiratory Syndrome Coronavirus 2 and its Seasonal Trends in Patients Attending a Tertiary Healthcare Centre in Rajasthan: A Retrospective Observational Study

Abstract

Introduction: The pandemic of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has drastically affected the global population, leading to high rates of morbidity and mortality. This virus originated in China had quickly spread to different countries worldwide, paralysing healthcare systems. Alongside supportive therapy, isolation, and contact tracing, vaccines have also played a crucial role in rescuing the human population from the virus. Aim: To evaluate the burden of SARS-CoV-2 and its seasonal trends. Materials and Methods: This retrospective observational study was conducted in the Department of Microbiology at the Ananta Institute of Medical Sciences and Research Centre in Rajsamand, Rajasthan, India. Data was collected from July 2020 to September 2022 and analysed from January 2023 to March 2023. The study included a sample size of 14,050. Nasopharyngeal and throat swab samples were collected into a single tube of Viral Transport Medium (VTM). Ribonucleic Acid (RNA) was extracted from the VTM, and real-time Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) was performed using different kits approved by the Indian Council of Medical Research (ICMR). Results were interpreted according to the manufacturer’s instructions. A Chisquared test was performed using GraphPad Prism version 9.2.0.332. A p-value of <0.05 was considered significant. Results: A total of 14,050 samples were evaluated, of which 2,861 (20.36%) tested positive for SARS-CoV-2. The highest positivity rate of 581 (4.13%) was observed in the age group of 41-50 years (p-value <0.0001). The maximum positivity for SARS-CoV-2 was found among individuals aged 21-60 years, accounting for 2,086 (14.85%) cases. Among the samples obtained from the Inpatient Department (IPD) and Outpatient Department (OPD), 913 (13.83%) (p-value=0.0014) and 1,948 (26.16%) tested positive for SARS-CoV-2, respectively. Male patients accounted for 1,869 (21%) (p-value=0.0194) positive cases, while female patients accounted for 992 (19.26%) (p-value <0.0001) positive cases. The highest positivity rate was recorded in April 2021, with 921 (6.55%) cases. Seasonal trends of SARS-CoV-2 showed two major peaks and a minor peak between July 2020 and September 2022. Symptomatic patients had a positivity rate of 987 (31.75%), while asymptomatic patients had a rate of 1,874 (17.13%) (p-value <0.0001). Conclusion: Enhanced precautionary measures are required for individuals aged 21-60 years, as they are more vulnerable to SARS-CoV-2. Asymptomatic patients had a positivity rate of 17.13%. Given the mixed trend of seasonal transmission of SARS-CoV-2, continuous surveillance of the virus is necessary. The study results will be useful for epidemiological purposes and for planning strategies aimed at reducing the duration of the pandemic.

Keywords

• asymptomatic patients
• mixed trends
• pandemic
• respiratory virus
• seasonal variation