The burden of active infection and anti-SARS-CoV-2 IgG antibodies in the general population: Results from a statewide sentinel-based population survey in Karnataka, India

Giridhara R. Babu, Public Health Foundation of India
Rajesh Sundaresan, Indian Institute of Science
Siva Athreya, Indian Statistical Institute Bangalore
Jawaid Akhtar, Government of Karnataka
Pankaj Kumar Pandey
Parimala S. Maroor
M. Rajagopal Padma
R. Lalitha, UNICEF
Mohammed Shariff
Lalitha Krishnappa, Ramaiah Medical College
C. N. Manjunath, Sri Jayadeva Institute of Cardiovascular Sciences and Research
Mysore Kalappa Sudarshan
Gopalkrishna Gururaj, National Institute of Mental Health and Neuro Sciences
Timmanahalli Sobagaiah Ranganath, Bangalore Medical College and Research Institute
Kumar D.E. Vasanth
Pradeep Banandur, National Institute of Mental Health and Neuro Sciences
Deepa Ravi, Public Health Foundation of India
Shilpa Shiju
Eunice Lobo, Public Health Foundation of India
Asish Satapathy, Member Technical Advisory Committee on COVID19
Lokesh Alahari, Member Technical Advisory Committee on COVID19
Prameela Dinesh
Vinitha Thakar
Anita Desai, National Institute of Mental Health and Neuro Sciences
Ambica Rangaiah, Bangalore Medical College and Research Institute
Ashok Munivenkatappa, National Institute of Virology India
Krishna S, Vijayanagar Institute of Medical Sciences
Shantala Gowdara Basawarajappa, Bangalore Medical College and Research Institute
H. G. Sreedhara, Hassan Institute of Medical Sciences
Siddesh KC, Shimoga Institute of Medical Sciences
Amrutha Kumari B, Mysore Medical College
Nawaz Umar, Gulbarga Institute of Medical Sciences
Mythri BA, Karnataka Institute of Medical Sciences

Article Type

Research Article

Publication Title

International Journal of Infectious Diseases

Abstract

Objective: To estimate the burden of active infection and anti-SARS-CoV-2 IgG antibodies in Karnataka, India, and to assess variation across geographical regions and risk groups. Methods: A cross-sectional survey of 16,416 people covering three risk groups was conducted between 3–16 September 2020 using the state of Karnataka's infrastructure of 290 healthcare facilities across all 30 districts. Participants were further classified into risk subgroups and sampled using stratified sampling. All participants were subjected to simultaneous detection of SARS-CoV-2 IgG using a commercial ELISA kit, SARS-CoV-2 antigen using a rapid antigen detection test (RAT) and reverse transcription-polymerase chain reaction (RT-PCR) for RNA detection. Maximum-likelihood estimation was used for joint estimation of the adjusted IgG, active and total prevalence (either IgG or active or both), while multinomial regression identified predictors. Results: The overall adjusted total prevalence of COVID-19 in Karnataka was 27.7% (95% CI 26.1–29.3), IgG 16.8% (15.5–18.1) and active infection fraction 12.6% (11.5–13.8). The case-to-infection ratio was 1:40 and the infection fatality rate was 0.05%. Influenza-like symptoms or contact with a COVID-19-positive patient were good predictors of active infection. RAT kits had higher sensitivity (68%) in symptomatic people compared with 47% in asymptomatic people. Conclusion: This sentinel-based population survey was the first comprehensive survey in India to provide accurate estimates of the COVID-19 burden. The findings provide a reasonable approximation of the population immunity threshold levels. Using existing surveillance platforms coupled with a syndromic approach and sampling framework enabled this model to be replicable.

First Page

27

Last Page

36

DOI

10.1016/j.ijid.2021.05.043

Publication Date

7-1-2021

Comments

Open Access, Green

This document is currently not available here.

Share

COinS