SARS-CoV-2 antibody seroprevalence in India, August-September, 2020: findings from the second nationwide household serosurvey.

The first national severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serosurvey in India, done in May-June, 2020, among adults aged 18 years or older from 21 states, found a SARS-CoV-2 IgG antibody seroprevalence of 0·73% (95% CI 0·34-1·13). We aimed to assess the more recent nationwide seroprevalence in the general population in India. We did a second household serosurvey among individuals aged 10 years or older in the same 700 villages or wards within 70 districts in India that were included in the first serosurvey. Individuals aged younger than 10 years and households that did not respond at the time of survey were excluded. Participants were interviewed to collect information on sociodemographics, symptoms suggestive of COVID-19, exposure history to laboratory-confirmed COVID-19 cases, and history of COVID-19 illness. 3-5 mL of venous blood was collected from each participant and blood samples were tested using the Abbott SARS-CoV-2 IgG assay. Seroprevalence was estimated after applying the sampling weights and adjusting for clustering and assay characteristics. We randomly selected one adult serum sample from each household to compare the seroprevalence among adults between the two serosurveys. Between Aug 18 and Sept 20, 2020, we enrolled and collected serum samples from 29 082 individuals from 15 613 households. The weighted and adjusted seroprevalence of SARS-CoV-2 IgG antibodies in individuals aged 10 years or older was 6·6% (95% CI 5·8-7·4). Among 15 084 randomly selected adults (one per household), the weighted and adjusted seroprevalence was 7·1% (6·2-8·2). Seroprevalence was similar across age groups, sexes, and occupations. Seroprevalence was highest in urban slum areas followed by urban non-slum and rural areas. We estimated a cumulative 74·3 million infections in the country by Aug 18, 2020, with 26-32 infections for every reported COVID-19 case. Approximately one in 15 individuals aged 10 years or older in India had SARS-CoV-2 infection by Aug 18, 2020. The adult seroprevalence increased approximately tenfold between May and August, 2020. Lower infection-to-case ratio in August than in May reflects a substantial increase in testing across the country. Indian Council of Medical Research.

Murhekar MV ，Bhatnagar T ，Selvaraju S ，Saravanakumar V ，Thangaraj JWV ，Shah N ，Kumar MS ，Rade K ，Sabarinathan R ，Asthana S ，Balachandar R ，Bangar SD ，Bansal AK ，Bhat J ，Chopra V ，Das D ，Deb AK ，Devi KR ，Dwivedi GR ，Khan SMS ，Kumar CPG ，Kumar MS ，Laxmaiah A ，Madhukar M ，Mahapatra A ，Mohanty SS ，Rangaraju C ，Turuk A ，Baradwaj DK ，Chahal AS ，Debnath F ，Haq I ，Kalliath A ，Kanungo S ，Kshatri JS ，Lakshmi GGJN ，Mitra A ，Nirmala AR ，Prasad GV ，Qurieshi MA ，Sahay S ，Sangwan RK ，Sekar K ，Shukla VK ，Singh PK ，Singh P ，Singh R ，Varma DS ，Viramgami A ，Panda S ，Reddy DCS ，Bhargava B ，ICMR Serosurveillance Group ... -  《Lancet Global Health》

Prevalence of SARS-CoV-2 infection in India: Findings from the national serosurvey, May-June 2020.

Murhekar MV ，Bhatnagar T ，Selvaraju S ，Rade K ，Saravanakumar V ，Vivian Thangaraj JW ，Kumar MS ，Shah N ，Sabarinathan R ，Turuk A ，Anand PK ，Asthana S ，Balachandar R ，Bangar SD ，Bansal AK ，Bhat J ，Chakraborty D ，Rangaraju C ，Chopra V ，Das D ，Deb AK ，Devi KR ，Dwivedi GR ，Salim Khan SM ，Haq I ，Kumar MS ，Laxmaiah A ，Madhuka ，Mahapatra A ，Mitra A ，Nirmala AR ，Pagdhune A ，Qurieshi MA ，Ramarao T ，Sahay S ，Sharma YK ，Shrinivasa MB ，Shukla VK ，Singh PK ，Viramgami A ，Wilson VC ，Yadav R ，Girish Kumar CP ，Luke HE ，Ranganathan UD ，Babu S ，Sekar K ，Yadav PD ，Sapkal GN ，Das A ，Das P ，Dutta S ，Hemalatha R ，Kumar A ，Narain K ，Narasimhaiah S ，Panda S ，Pati S ，Patil S ，Sarkar K ，Singh S ，Kant R ，Tripathy S ，Toteja GS ，Babu GR ，Kant S ，Muliyil JP ，Pandey RM ，Sarkar S ，Singh SK ，Zodpey S ，Gangakhedkar RR ，S Reddy DC ，Bhargava B ... -  《-》

Seroprevalence of IgG antibodies against SARS-CoV-2 among the general population and healthcare workers in India, June-July 2021: A population-based cross-sectional study.

Murhekar MV ，Bhatnagar T ，Thangaraj JWV ，Saravanakumar V ，Santhosh Kumar M ，Selvaraju S ，Rade K ，Kumar CPG ，Sabarinathan R ，Asthana S ，Balachandar R ，Bangar SD ，Bansal AK ，Bhat J ，Chakraborty D ，Chopra V ，Das D ，Devi KR ，Dwivedi GR ，Jain A ，Khan SMS ，Kumar MS ，Laxmaiah A ，Madhukar M ，Mahapatra A ，Ramesh T ，Rangaraju C ，Turuk J ，Yadav S ，Bhargava B ，ICMR serosurveillance group ... -  《-》

SARS-CoV-2 antibody seroprevalence in the general population and high-risk occupational groups across 18 cities in Iran: a population-based cross-sectional study.

Rapid increases in cases of COVID-19 were observed in multiple cities in Iran towards the start of the pandemic. However, the true infection rate remains unknown. We aimed to assess the seroprevalence of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 18 cities of Iran as an indicator of the infection rate. In this population-based cross-sectional study, we randomly selected and invited study participants from the general population (from lists of people registered with the Iranian electronic health record system or health-care centres) and a high-risk population of individuals likely to have close social contact with SARS-CoV-2-infected individuals through their occupation (from employee lists provided by relevant agencies or companies, such as supermarket chains) across 18 cities in 17 Iranian provinces. Participants were asked questions on their demographic characteristics, medical history, recent COVID-19-related symptoms, and COVID-19-related exposures. Iran Food and Drug Administration-approved Pishtaz Teb SARS-CoV-2 ELISA kits were used to detect SARS-CoV-2-specific IgG and IgM antibodies in blood samples from participants. Seroprevalence was estimated on the basis of ELISA test results and adjusted for population weighting (by age, sex, and city population size) and test performance (according to our independent validation of sensitivity and specificity). From 9181 individuals who were initially contacted between April 17 and June 2, 2020, 243 individuals refused to provide blood samples and 36 did not provide demographic information and were excluded from the analysis. Among the 8902 individuals included in the analysis, 5372 had occupations with a high risk of exposure to SARS-CoV-2 and 3530 were recruited from the general population. The overall population weight-adjusted and test performance-adjusted prevalence of antibody seropositivity in the general population was 17·1% (95% CI 14·6-19·5), implying that 4 265 542 (95% CI 3 659 043-4 887 078) individuals from the 18 cities included were infected by the end of April, 2020. The adjusted seroprevalence of SARS-CoV-2-specific antibodies varied greatly by city, with the highest estimates found in Rasht (72·6% [53·9-92·8]) and Qom (58·5% [37·2-83·9]). The overall population weight-adjusted and test performance-adjusted seroprevalence in the high-risk population was 20·0% (18·5-21·7) and showed little variation between the occupations included. Seroprevalence is likely to be much higher than the reported prevalence of COVID-19 based on confirmed COVID-19 cases in Iran. Despite high seroprevalence in a few cities, a large proportion of the population is still uninfected. The potential shortcomings of current public health policies should therefore be identified to prevent future epidemic waves in Iran. Iranian Ministry of Health and Medical Education. For the Farsi translation of the abstract see Supplementary Materials section.

Poustchi H ，Darvishian M ，Mohammadi Z ，Shayanrad A ，Delavari A ，Bahadorimonfared A ，Eslami S ，Javanmard SH ，Shakiba E ，Somi MH ，Emami A ，Saki N ，Hormati A ，Ansari-Moghaddam A ，Saeedi M ，Ghasemi-Kebria F ，Mohebbi I ，Mansour-Ghanaei F ，Karami M ，Sharifi H ，Pourfarzi F ，Veisi N ，Ghadimi R ，Eghtesad S ，Niavarani A ，Ali Asgari A ，Sadeghi A ，Sorouri M ，Anushiravani A ，Amani M ，Kaveh S ，Feizesani A ，Tabarsi P ，Keyvani H ，Markarian M ，Shafighian F ，Sima A ，Sadjadi A ，Radmard AR ，Mokdad AH ，Sharafkhah M ，Malekzadeh R ... -  《-》

Seroprevalence of SARS-CoV-2 in Bhubaneswar, India: findings from three rounds of community surveys.

Kshatri JS ，Bhattacharya D ，Praharaj I ，Mansingh A ，Parai D ，Kanungo S ，Palo SK ，Giri S ，Pattnaik M ，Barik SR ，Dash GC ，Choudhary HR ，Turuk J ，Mandal NN ，Pati S ... -  《-》