Serological evidence of human infection with SARS-CoV-2: a systematic review and meta-analysis

Abstract

Background A rapidly increasing number of serological surveys for antibodies to SARS-CoV-2 have been reported worldwide. We aimed to synthesise, combine, and assess this large corpus of data.Methods In this systematic review and meta-analysis, we searched PubMed, Embase, Web of Science, and five preprint servers for articles published in English between Dec 1, 2019, and Dec 22, 2020. Studies evaluating SARS-CoV-2 seroprevalence in humans after the first identified case in the area were included. Studies that only reported serological responses among patients with COVID-19, those using known infection status samples, or any animal experiments were all excluded. All data used for analysis were extracted from included papers. Study quality was assessed using a standardised scale. We estimated age-specific, sex-specific, and race-specific seroprevalence by WHO regions and subpopulations with different levels of exposures, and the ratio of serology-identified infections to virologically confirmed cases. This study is registered with PROSPERO, CRD42020198253.Findings 16 506 studies were identified in the initial search, 2523 were assessed for eligibility after removal of duplicates and inappropriate titles and abstracts, and 404 serological studies (representing tests in 5 168 360 individuals) were included in the meta-analysis. In the 82 studies of higher quality, close contacts (18•0%, 95% CI 15•7-20•3) and highrisk health-care workers (17•1%, 9•9-24•4) had higher seroprevalence than did low-risk health-care workers (4•2%, 1•5-6•9) and the general population (8•0%, 6•8-9•2). The heterogeneity between included studies was high, with an overall I² of 99•9% (p<0•0001). Seroprevalence varied greatly across WHO regions, with the lowest seroprevalence of general populations in the Western Pacific region (1•7%, 95% CI 0•0-5•0). The pooled infection-to-case ratio was similar between the region of the Americas (6•9, 95% CI 2•7-17•3) and the European region (8•4, 6•5-10•7), but higher in India (56•5, 28•5-112•0), the only country in the South-East Asia region with data.Interpretation Antibody-mediated herd immunity is far from being reached in most settings. Estimates of the ratio of serologically detected infections per virologically confirmed cases across WHO regions can help provide insights into the true proportion of the population infected from routine confirmation data.

SARS-CoV-2 Seroprevalence in Healthcare Workers in Germany: A Follow-Up Study

“…The authors supposed a shortage of protective supplies to be the reason for the elevated infection rates and deaths. Even with the observed increase of the COVID-19 seroprevalence in the high-risk group at the University Hospital Essen, the seroprevalence was low compared to several other centers in Europe and the world, as shown in a metanalysis by Chen et al [ 15 ]. We should stress, however, that the metanalysis included just two studies with low-risk-HCW from Europe, and the overall seroprevalence of 3.1% was based on data from just one study performed in March and April of 2020 in Western Germany [ 16 ].…”

Impaired Glucose-Insulin Metabolism in Multisystem Inflammatory Syndrome Related to SARS-CoV-2 in Children

“…Our results are not surprising in terms of adaptive metabolic response; nevertheles in this clinical context, a bidirectional relationship between COVID-19 and glycemic im pairment could not be excluded. Pancreatic β cells are permissive to SARS-CoV-2 infec tion with receptor angiotensin-converting enzyme 2 (ACE2) as its entry [37,38]. As con…”

“…Our results are not surprising in terms of adaptive metabolic response; nevertheless, in this clinical context, a bidirectional relationship between COVID-19 and glycemic impairment could not be excluded. Pancreatic β cells are permissive to SARS-CoV-2 infection with receptor angiotensin-converting enzyme 2 (ACE2) as its entry [37,38]. As considered by Hoffmann [2], hyperglycemia and glycemic fluctuations could be caused by the inflam-matory cascade of the attack of SARS-CoV-2 on the pancreas and the potentially impaired β-cell function.…”

Persistence and detection of anti-SARS-CoV-2 antibodies: immunoassay heterogeneity and implications for serosurveillance

“…Serosurveys have played an important role during the COVID-19 pandemic by helping track the true extent of transmission in different populations ( 1 – 4 ), and estimating key epidemiologic indicators such as the infection fatality ratio (IFR) ( 5 – 7 ). More than 400 serosurveys were published by the end of 2020, using dozens of different immunoassays, designed to detect antibodies targeting primarily all or part of the spike (S) or nucleocapsid (N) proteins of the SARS-CoV-2 virus ( 8 ). The accuracy of serology-based estimates depends on the immunoassay antibody targets and their performance in detecting both recent and historic infections.…”