Seroprevalence of SARS-CoV-2, Symptom Profiles and Sero-Neutralization in a Suburban Area, France

  1. Anne Gégout Petit
  2. Hélène Jeulin
  3. Karine Legrand
  4. Nicolas Jay
  5. Agathe Bochnakian
  6. Pierre Vallois
  7. Evelyne Schvoerer
  8. Francis Guillemin

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Abstract

The World Health Organisation recommends monitoring the circulation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We investigated anti–SARS-CoV-2 total immunoglobulin (IgT) antibody seroprevalence and in vitro sero-neutralization in Nancy, France, in spring 2020. Individuals were randomly sampled from electoral lists and invited with household members over 5 years old to be tested for anti–SARS-CoV-2 (IgT, i.e., IgA/IgG/IgM) antibodies by ELISA (Bio-rad); the sero-neutralization activity was evaluated on Vero CCL-81 cells. Among 2006 individuals, the raw seroprevalence was 2.1% (95% confidence interval 1.5 to 2.9), was highest for 20- to 34-year-old participants (4.7% (2.3 to 8.4)), within than out of socially deprived area (2.5% vs. 1%, p = 0.02) and with than without intra-family infection (p < 10−6). Moreover, 25% of participants presented at least one COVID-19 symptom associated with SARS-CoV-2 positivity (p < 10−13), with highly discriminant anosmia or ageusia (odds ratio 27.8 [13.9 to 54.5]); 16.3% (6.8 to 30.7) of seropositive individuals were asymptomatic. Positive sero-neutralization was demonstrated in vitro for 31/43 seropositive subjects. Regarding the very low seroprevalence, a preventive effect of the lockdown in March 2020 can be assumed for the summer, but a second COVID-19 wave, as expected, could be subsequently observed in this poorly immunized population.

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  1. ScreenIT

    SciScore for 10.1101/2021.02.10.21250862: (What is this?)

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

    Table 1: Rigor

    Ethicsnot detected.
    Sex as a biological variablenot detected.
    RandomizationAdults randomly sampled from the electoral lists were invited to participate with all household members.
    Blindingnot detected.
    Power Analysisnot detected.
    Cell Line Authenticationnot detected.

    Table 2: Resources

    Antibodies
    SentencesResources
    IgM and IgG antibodies were detected by using an imunochromatographic test (Biosynex), with IgA by ELISA (Anti-SARS-CoV-2 Assay, Euroimmun) on SARS-CoV-2–seropositive samples and on samples from SARS-CoV-2–seronegative individuals living with SARS-CoV-2–positive individuals.
    IgM
    suggested: None
    IgG
    suggested: None
    Sera positive for anti-SARS-Cov-2 antibodies were diluted from 1/10 to 1/640 and incubated with virus suspension for 2 hr.
    anti-SARS-Cov-2
    suggested: None
    Experimental Models: Cell Lines
    SentencesResources
    Seroneutralization assay: The SARS-CoV-2 strain from a positive respiratory sample (Covi-Lor collection, Nancy University hospital, France) was cultured on Vero CCL-81 cells (provided by L2CM Laboratory, Nancy).
    Vero CCL-81
    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:
    Third, seroneutralization capacity was investigated in duplicate, in line with recommended standard practices, instead of derived from IgG results (33,34) The study has some limitations. First, the sampling electoral database, chosen for its immediate availability in such a small and delimited area, did not completely cover the adult population because some people left the area (among the 6094 people invited, 38% were not really solicited [wrong addresses, death etc.]), newcomers to the area did not yet register (not mandatory), and non-European citizens were not eligible, which creates some representativeness bias (35). Second, the estimated response rate was relatively low in a period immediately following the lockdown, with many people already gone away for July summer holidays. Third, all data were self-reported, which may lead to some measurement (declaration) bias. Moreover, even if the number of individuals was sufficient to satisfy the main objective, the study lacked statistical power for the study of risk factors. Finally, with novel SARS-CoV-2 variants emerging all over the world (36), the neutralizing activity of positive sera against novel SARS-CoV-2 variants could be evaluated. In conclusion, IgT assays are key tools to monitor the circulation of SARS-CoV-2 and the impact of public health guidelines (37). In this population of low anti-SARS-CoV-2 seroprevalence, a beneficial effect of the lockdown can be assumed with frequent SARS-CoV-2 seroneutralization among ...

    Results from TrialIdentifier: We found the following clinical trial numbers in your paper:

    IdentifierStatusTitle
    NCT04448769CompletedEpidemiological Study of Seroprevalence Against the SARS-CoV…

    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.

    Results from scite Reference Check: We found no unreliable references.

    About SciScore

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  2. Version published to 10.3390/v13061076
  3. Version published to 10.1101/2021.02.10.21250862 on medRxiv