SARS-CoV-2 seroprevalence among the general population and healthcare workers in India, December 2020–January 2021
Manoj Murhekar, Tarun Bhatnagar, Jeromie Wesley Vivian Thangaraj, V. Saravanakumar, Muthusamy Santhosh Kumar, Sriram Selvaraju, Kiran Rade, C. P. Girish Kumar, R. Sabarinathan, Alka Turuk, Smita Asthana, Rakesh Balachandar, Sampada Dipak Bangar, Avi Kumar Bansal, Vishal Chopra, Dasarathi Das, Alok Kumar Deb, Kangjam Rekha Devi, Vikas Dhikav, Gaurav Raj Dwivedi, Muhammad Salim Khan, M. Sunil Kumar, Avula Laxmaiah, Major Madhukar, Amarendra Mahapatra, Chethana Rangaraju, Jyotirmayee Turuk, Rajiv Yadav, Rushikesh Andhalkar, K. Arunraj, Dinesh Kumar Bharadwaj, Pravin Bharti, Debdutta Bhattacharya, Jyothi Bhat, Ashrafjit S. Chahal, Debjit Chakraborty, Anshuman Chaudhury, Hirawati Deval, Sarang Dhatrak, R. S. Dayal, D. Elantamilan, Prathiksha Giridharan, Inaamul Haq, Ramesh Kumar Hudda, Babu Jagjeevan, Arshad Kalliath, Srikanta Kanungo, Nivethitha N. Krishnan, Jaya Singh Kshatri, Alok Kumar, Niraj Kumar, Virendra Kumar, Gangeti Gandhi Jayanthi Naga Lakshmi, Ganesh Mehta, Nandan Kumar Mishra, Anindya Mitra, K. Nagbhushanam, Nimmathota Arlappa, A Nirmala, Ashok Kumar Pandey, Ganta Venkata Prasad, Mariya Amin Qurieshi, Sirasanambatti Devarajulu Reddy, Aby Robinson, Seema Sahay, Rochak Saxena, Krithikaa Sekar, Vijay K. Shukla, Hari Bhan Singh, Prashant Kumar Singh, Pushpendra Singh, Rajeev Singh, Nivetha Srinivasan, Dantuluri Sheethal Varma, Ankit Viramgami, Vimith Cheruvathoor Wilson, Surabhi Yadav, Suresh Yadav, Kamran Zaman, Amit Chakrabarti, Aparup Das, Rupinder Singh Dhaliwal, Shanta Dutta, Rajni Kant, Anam Khan, Kanwar Narain, Somashekar Narasimhaiah, Chandrasekaran Padmapriyadarshini, Krishna Pandey, Sanghamitra Pati, Shripad A. Patil, Hemalatha Rajkumar, Tekumalla Ramarao, Y.K. Sharma, Shalini Singh, Samiran Panda, D. C. S. Reddy, Balram Bhargava, Tanu Anand, Giridhara R. Babu
Abstract
BACKGROUND: Earlier serosurveys in India revealed seroprevalence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) of 0.73% in May-June 2020 and 7.1% in August-September 2020. A third serosurvey was conducted between December 2020 and January 2021 to estimate the seroprevalence of SARS-CoV-2 infection among the general population and healthcare workers (HCWs) in India. METHODS: The third serosurvey was conducted in the same 70 districts as the first and second serosurveys. For each district, at least 400 individuals aged ≥10 years from the general population and 100 HCWs from subdistrict-level health facilities were enrolled. Serum samples from the general population were tested for the presence of immunoglobulin G (IgG) antibodies against the nucleocapsid (N) and spike (S1-RBD) proteins of SARS-CoV-2, whereas serum samples from HCWs were tested for anti-S1-RBD. Weighted seroprevalence adjusted for assay characteristics was estimated. RESULTS: Of the 28,598 serum samples from the general population, 4585 (16%) had IgG antibodies against the N protein, 6647 (23.2%) had IgG antibodies against the S1-RBD protein, and 7436 (26%) had IgG antibodies against either the N protein or the S1-RBD protein. Weighted and assay-characteristic-adjusted seroprevalence against either of the antibodies was 24.1% [95% confidence interval (CI) 23.0-25.3%]. Among 7385 HCWs, the seroprevalence of anti-S1-RBD IgG antibodies was 25.6% (95% CI 23.5-27.8%). CONCLUSIONS: Nearly one in four individuals aged ≥10 years from the general population as well as HCWs in India had been exposed to SARS-CoV-2 by December 2020.