Estimates of the rate of infection and asymptomatic COVID-19 disease in a population sample from SE England

Abstract

Background: Understanding of the true asymptomatic rate of infection of SARS-CoV-2 is currently limited, as is understanding of the population-based seroprevalence after the first wave of COVID-19 within the UK. The majority of data thus far come from hospitalised patients, with little focus on general population cases, or their symptoms. Methods: We undertook enzyme linked immunosorbent assay characterisation of IgM and IgG responses against SARS-CoV-2 spike glycoprotein and nucleocapsid protein of 431 unselected general-population participants of the TwinsUK cohort from South-East England, aged 19-86 (median age 48; 85% female). 382 participants completed prospective logging of 14 COVID-19 related symptoms via the COVID Symptom Study App, allowing consideration of serology alongside individual symptoms, and a predictive algorithm for estimated COVID-19 previously modelled on PCR positive individuals from a dataset of over 2 million. Findings: We demonstrated a seroprevalence of 12% (51participants of 431). Of 48 seropositive individuals with full symptom data, nine (19%) were fully asymptomatic, and 16 (27%) were asymptomatic for core COVID-19 symptoms: fever, cough or anosmia. Specificity of anosmia for seropositivity was 95%, compared to 88% for fever cough and anosmia combined. 34 individuals in the cohort were predicted to be Covid-19 positive using the App algorithm, and of those, 18 (52%) were seropositive. Interpretation: Seroprevalence amongst adults from London and South-East England was 12%, and 19% of seropositive individuals with prospective symptom logging were fully asymptomatic throughout the study. Anosmia demonstrated the highest symptom specificity for SARS-CoV-2 antibody response. Funding: NIHR BRC, CDRF, ZOE global LTD, RST-UKRI/MRC

Seroprevalence and SARS-CoV-2 invasion in general populations: A scoping review over the first year of the pandemic

“…(Q1-Q3 1-3%) to 31.5% (3-7%). Only 35 articles explicitely assessed asymptomatic populations [18,19,[24][25][26]32,45,47,53,56,59,64,66,69,75,76,78,81,83,89,90,92,93,95,98,99,102,[105][106][107][108][109][110][111][112][113][114]. The symptoms most strongly associated with seropositivity were anosmia, agueusia, fever, fatigue, rhinorrhea, sore throat, breathing difficulties, flu-like symptoms, cough, dyspnoea, myalgias, headache and asthenia.…”

Translational Research in the Time of COVID-19—Dissolving Boundaries

“…Our assessment highlights (at least) 4 areas of thriving translational research: (1) 'delivering and adapting the clinical service'-caring for COVID-19 patients on an infectious diseases ward whilst providing a consult and infection prevention and control service across the hospitals. This gave visibility of core and rapidly changing clinical needs; (2) 'developing laboratory diagnostic capability'-setting up a new COVID-19 diagnostic expansion laboratory embedded within academic research facilities at Guy's Hospital introducing novel accredited pipelines; technologies; PCR or serological tests; and COVID-19 or metagenomic sequencing for clinical service, infection control, and public health asymptomatic screening [5][6][7][8] (we named this new laboratory in recognition of June Almeida who discovered coronaviruses by electron microscopy at St Thomas' Hospital in 1966 [9]); (3) 'conducting fundamental research'-comprehensive immunophenotyping to understand correlates of disease/protection and to inform novel therapies; virus culture to dissect viral replication and support preclinical drug discovery; and viral sequencing to inform transmission networks, immune escape, and persistence [10][11][12]; (4) 'supporting therapeutics and vaccine research'-recruiting patients into nationally coordinated clinical trials of new therapies (e.g., convalescent serum, vaccines, and biologics) and participating in cohort-based and population studies to explore, inter alia, rates of infection, disease severity risk factors, and renewed or persistent COVID-19 infection [13].…”

Calculating incidence of Influenza-like and COVID-like symptoms from Flutracking participatory survey data

“…For example, previous studies, including current weekly Flutracking reports [13] , focus solely on experiences of ILI defined as new onset of both cough and fever in the same week [8] . While these symptoms are commonly viewed as core components of ILI [10] , this criteria may be insufficient for investigating the rates of a wider range of respiratory illnesses, and in particular, would miss the majority of COVID-19 cases [20] , [29] , [31] .…”