Clinico-Epidemiological Profile of COVID-19 Patients with Omicron Variant Admitted in a Tertiary Care Center, South India

Theranirajan Ethirajan,1,* Gopalakrishnan Natarajan,2,* Rajendran Velayudham,3,* Pavithra Jayakumaran,4 Indumathi Karnan,1 Karthick Rajendran,5 Sudhakaran Doraisamy,6 Sripriya Chenakeswarar Sridhar,7 Purushoth Kumaran,1 Kabilan Kamaraj,1 Anuradha Kandasamy,7 Murugan Natarajan8 1Madras Medical College, Chennai, India; 2Institute of Nephrology, Madras Medical College, Chennai, India; 3Institute of Internal Medicine, Madras Medical College, Chennai, India; 4Institute of Pathology, Madras Medical College, Chennai, India; 5Multidisciplinary Research Unit (MRU), Madras Medical College, Chennai, India; 6Critical Care Medicine, Madras Medical College, Chennai, India; 7Viral Research and Diagnostic Laboratory, Madras Medical College, Chennai, India; 8Institute of Thoracic Medicine, Madras Medical College, Chennai, India*These authors contributed equally to this workCorrespondence: Murugan Natarajan, Institute of Thoracic Medicine, Madras Medical College and Rajiv Gandhi Government General Hospital, Chennai, Tamil Nadu, 600003, India, Email stanleymurugan@gmail.comBackground and Objectives: Omicron, a variant of SARS COV2, is looming large as a cause of global concern. Its high transmissibility can pose challenges in healthcare allocation in a highly populous country like India. Studying the behaviour of the virus among the Indian population will definitely help in planning for the impending omicron surge, so we conducted a preliminary analysis of the clinical and epidemiological characteristics of the suspected omicron cases in the early part of the surge.Methodology: The study was conducted in the Rajiv Gandhi Government General Hospital, from 17th December 2021 to 11th January 2022. A total number of 159 consecutive patients ≥ 18 years of age with the S gene target failure were enrolled and clinically followed up during hospitalisation.Results: Nearly half (n = 79, 49.7%) were aged between 18 and 30 years and the mean (SD) age of the patients was 35.1 (14.9); 52.8% (n = 84) were males and 54.7% (n = 87) were healthcare workers. The NLR ratio and CRP were raised in unvaccinated individuals. Out of 159 patients, only 4 patients required oxygen and all the others showed a mild course of illness and there was no mortality.Conclusion: The clinical course of suspected omicron patients was mild in those who were vaccinated. Unvaccinated individuals with comorbid illness need to be closely monitored for prompt referral for acute care. Further studies are needed in the high-risk group with omicron.Keywords: COVID-19, coronavirus, SARS-CoV-2, omicron, variant of concern, S gene target failure