tetano
Editor, Senior Moderator
Cureus
. 2022 Jul 28;14(7):e27428.
doi: 10.7759/cureus.27428. eCollection 2022 Jul.
SARS-CoV-2 Seroprevalence in Delhi, India, During September-October 2021: A Population-Based Seroepidemiological Study
Pragya Sharma[SUP] 1 [/SUP], Saurav Basu[SUP] 2 [/SUP], Suruchi Mishra[SUP] 3 [/SUP], Ekta Gupta[SUP] 4 [/SUP], Reshu Agarwal[SUP] 4 [/SUP], Pratibha Kale[SUP] 5 [/SUP], Nutan Mundeja[SUP] 6 [/SUP], B S Charan[SUP] 7 [/SUP], Gautam Singh[SUP] 8 [/SUP], Mongjam Singh[SUP] 1 [/SUP]
Affiliations
Abstract
Background A previous community-based severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serosurvey in Delhi in January 2021 reported a seroprevalence of 50.52%. We conducted a repeat serosurvey to obtain a recent estimate of the seroprevalence of IgG SARS-CoV-2 in the general population of Delhi, India. Methods This cross-sectional study was conducted from September 24 to October 14, 2021, in 274 wards of Delhi among 27,811 participants through a multistage sampling technique. Results The crude seroprevalence was 89.5% (95% CI 89.1, 89.8), weight for age and sex was 88% (95% CI 87.6, 88.4), and after adjustment for assay performance was estimated as 97.5% (95% CI 97.0, 98.0). On adjusted analysis, the odds of seroconversion in the participants vaccinated with at least one dose of either COVID-19 vaccine (Covishield/Covaxin) was more than four times compared to the unvaccinated ones (aOR 4.2 (3.8, 4.6)). 86.8% of the seropositive individuals had a SARS-CoV-2 signal/cut-off ≥4.0 although it was significantly lower in the pediatric age group. Post-second wave (August to October 2021), on average there were daily 39 new COVID-19 cases and 0.44 deaths which during Omicron driven the third wave in January to March 2022 increased to daily 4,267 cases and 11.6 deaths. Conclusion A high prevalence of IgG antibodies against SARS-CoV-2 with likely higher antibody titres in the vaccinated compared to the unvaccinated groups with evidence of hybrid immunity in a majority of the population was protective against severe disease during transmission of subsequent omicron variants.
Keywords: covid-19; india; seroprevalence; serosurvey; vaccination.
. 2022 Jul 28;14(7):e27428.
doi: 10.7759/cureus.27428. eCollection 2022 Jul.
SARS-CoV-2 Seroprevalence in Delhi, India, During September-October 2021: A Population-Based Seroepidemiological Study
Pragya Sharma[SUP] 1 [/SUP], Saurav Basu[SUP] 2 [/SUP], Suruchi Mishra[SUP] 3 [/SUP], Ekta Gupta[SUP] 4 [/SUP], Reshu Agarwal[SUP] 4 [/SUP], Pratibha Kale[SUP] 5 [/SUP], Nutan Mundeja[SUP] 6 [/SUP], B S Charan[SUP] 7 [/SUP], Gautam Singh[SUP] 8 [/SUP], Mongjam Singh[SUP] 1 [/SUP]
Affiliations
- PMID: 36051724
- PMCID: PMC9420192
- DOI: 10.7759/cureus.27428
Abstract
Background A previous community-based severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serosurvey in Delhi in January 2021 reported a seroprevalence of 50.52%. We conducted a repeat serosurvey to obtain a recent estimate of the seroprevalence of IgG SARS-CoV-2 in the general population of Delhi, India. Methods This cross-sectional study was conducted from September 24 to October 14, 2021, in 274 wards of Delhi among 27,811 participants through a multistage sampling technique. Results The crude seroprevalence was 89.5% (95% CI 89.1, 89.8), weight for age and sex was 88% (95% CI 87.6, 88.4), and after adjustment for assay performance was estimated as 97.5% (95% CI 97.0, 98.0). On adjusted analysis, the odds of seroconversion in the participants vaccinated with at least one dose of either COVID-19 vaccine (Covishield/Covaxin) was more than four times compared to the unvaccinated ones (aOR 4.2 (3.8, 4.6)). 86.8% of the seropositive individuals had a SARS-CoV-2 signal/cut-off ≥4.0 although it was significantly lower in the pediatric age group. Post-second wave (August to October 2021), on average there were daily 39 new COVID-19 cases and 0.44 deaths which during Omicron driven the third wave in January to March 2022 increased to daily 4,267 cases and 11.6 deaths. Conclusion A high prevalence of IgG antibodies against SARS-CoV-2 with likely higher antibody titres in the vaccinated compared to the unvaccinated groups with evidence of hybrid immunity in a majority of the population was protective against severe disease during transmission of subsequent omicron variants.
Keywords: covid-19; india; seroprevalence; serosurvey; vaccination.