ABSTRACT
The pandemic of COVID-19 disease caused by SARS-CoV-2 continues to be the global public health concern. While nations are taking extensive measures to contain the pandemic, several variants have been identified more recently due to mutations of the SARS -CoV 2 which make it highly contagious and well known source of multiple waves. A retrospective and observational study were conducted on 28,897 nasopharyngeal/ oropharyngeal swabs of patients consulted or hospitalized at tertiary care hospital. The Epidemiological, demographic & clinical details of all patients were recorded and the diagnosis of SARS- CoV 2 was done by real time reverse transcriptase reaction (RT-PCR). A total 4794(16.6 %) patients were tested positive for SARS CoV-2 & maximum cases (38.57%) were in age group 41-60 years;males (51.48%) were found to be predominantly infected .In year 2020 maximum positivity of SARS -CoV 2 were reported in the months of August & September (14.72%), then gradual decline from October to Feb 21 and then second wave lead to abrupt rise, 34.42% cases reported in the month of April- May 2021. More than 75% of positive patients were found to be symptomatic and the most frequent symptoms were fever (82.14%), cough (71.69%), and sore throat (43.5%). Severe acute respiratory illness (SARI) was detected in 38.06 % of positive cases & Influenza like illness (ILI) was reported in 11.28%. Fifty one (51) positive samples tested for whole genome sequencing, detected 56.8% B.1.1.7 lineage (alpha variant), (39.3%) B.1.617.2 lineage (delta variant) and 3.9% delta plus variants (A.Y 4 & A.Y 12). As the pandemic continues to unfold, there is need to analyse the epidemiogical & clinical characteristics of the patients infected with SARS CoV 2 and identification of ongoing variants of concern in the presence of new selection pressures such as vaccination.