“SARS-CoV-2 antibody seroprevalence and stability in a tertiary care hospital-setting”

  1. Samreen Siddiqui
  2. Salwa Naushin
  3. Shalini Pradhan
  4. Archa Misra
  5. Akansha Tyagi
  6. Menka Loomba
  7. Swati Waghdhare
  8. Rajesh Pandey
  9. Shantanu Sengupta
  10. Sujeet Jha

Reviewed by

Read the full article See related articles

Listed in

Log in to save this article

Abstract

Background

SARS-CoV-2 infection has caused 64,469 deaths in India, with 7, 81, 975 active cases till 30 th August 2020, lifting it to 3 rd rank globally. To estimate the burden of the disease with time it is important to undertake a longitudinal seroprevalence study which will also help to understand the stability of anti SARS-CoV-2 antibodies. Various studies have been conducted worldwide to assess the antibody stability. However, there is very limited data available from India. Healthcare workers (HCW) are the frontline workforce and more exposed to the COVID-19 infection (SARS-CoV-2) compared to the community. This study was conceptualized with an aim to estimate the seroprevalence in hospital and general population and determine the stability of anti SARS-CoV-2 antibodies in HCW.

Methods

Staff of a tertiary care hospital in Delhi and individuals visiting that hospital were recruited between April to August 2020. Venous blood sample, demographic, clinical, COVID-19 symptoms, and RT-PCR data was collected from all participants. Serological testing was performed using the electro-chemiluminescence based assay developed by Roche Diagnostics, in Cobas Elecsys 411. Seropositive participants were followed- upto 83 days to check for the presence of antibodies.

Results

A total of 780 participants were included in this study, which comprised 448 HCW and 332 individuals from the general population. Among the HCW, seroprevalence rates increased from 2.3% in April to 50.6% in July. The cumulative prevalence was 16.5% in HCW and 23.5% (78/332) in the general population with a large number of asymptomatic individuals. Out of 74 seropositive HCWs, 51 were followed-up for the duration of this study. We observed that in all seropositive cases the antibodies were sustained even up to 83 days.

Conclusion

The cumulative prevalence of seropositivity was lower in HCWs than the general population. There were a large number of asymptomatic cases and the antibodies developed persisted through the duration of the study. More such longitudinal serology studies are needed to better understand the antibody response kinetics.

Article activity feed

  1. ScreenIT

    SciScore for 10.1101/2020.09.02.20186486: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    Institutional Review Board StatementIACUC: Ethics approval was taken from the Institutional Ethics Committee of Max Super Speciality Hospital,
    Consent: Written informed consent was obtained from all participants.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variablenot detected.

    Table 2: Resources

    Antibodies
    SentencesResources
    Participants who were found seropositive were contacted for follow-up and their blood samples were collected for checking the stability of the anti SARS-CoV-2 antibodies.
    anti SARS-CoV-2
    suggested: None

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    One of the major limitations of this survey was that it was done over a very short period of time during the whole pandemic period. Our data on seropositivity amongst individuals visiting the hospital (23.5%) is in concordance with the Delhi sero survey. However, the seroprevalence was lower amongst healthcare workers (16.5%). Interestingly, even among the healthcare workers, doctors and nurses who are actually in close proximity to the COVID-19 cases had lower seropositivity. Although counterintuitive, it can be perceived that healthcare workers in general and doctors and nurses in particular strictly follow all the guidelines that help in protecting them against infection. Several studies have been conducted globally to estimate the seroconversion rate among the HCW as well as the general population, including both symptomatic and asymptomatic individuals7-12. However, only a few studies have been done on antibody stability, including the population-based seroepidemiological study conducted in Spain which reported ∼90% seroprevalence after 14 days since the positive RT-PCR18. A multi-centre cohort study in the U.K tested HCWs and observed 47% seropositivity at more than 14 days after onset of symptoms5. Long et al, in China reported that the levels of neutralizing antibodies against SARSCoV-2, in those recovered from the disease, start decreasing after 2–3 months of infection21. Another such study noticed anti-SARS-CoV-2 IgM in one of the cases at 42 days after positive RT-...

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    About SciScore

    SciScore is an automated tool that is designed to assist expert reviewers by finding and presenting formulaic information scattered throughout a paper in a standard, easy to digest format. SciScore checks for the presence and correctness of RRIDs (research resource identifiers), and for rigor criteria such as sex and investigator blinding. For details on the theoretical underpinning of rigor criteria and the tools shown here, including references cited, please follow this link.

  2. Version published to 10.1101/2020.09.02.20186486 on medRxiv