Prospective epidemiological, molecular, and genetic characterization of a novel coronavirus disease in the Val Venosta/Vinschgau: the CHRIS COVID-19 study protocol

Abstract

The COVID-19 pandemic has been threatening the healthcare and socioeconomic systems of entire nations. While population-based surveys to assess the distribution of SARS-CoV-2 infection have become a priority, pre-existing longitudinal studies are ideally suited to assess the determinants of COVID-19 onset and severity.The Cooperative Health Research In South Tyrol (CHRIS) study completed the baseline recruitment of 13,393 adults from the Venosta/Vinschgau rural district in 2018, collecting extensive phenotypic and biomarker data, metabolomic data, densely imputed genotype and whole-exome sequencing data.Based on CHRIS, we designed a prospective study, called CHRIS COVID-19, aimed at: 1) estimating the incidence of SARS-CoV-2 infections; 2) screening for and investigating the determinants of incident infection among CHRIS participants and their household members; 3) monitoring the immune response of infected participants prospectively.An online screening questionnaire was sent to all CHRIS participants and their household members. A random sample of 1450 participants representative of the district population was invited to assess active (nasopharyngeal swab) or past (serum antibody test) infections. We prospectively invited for complete SARS-CoV-2 testing all questionnaire completers gauged as possible cases of past infection and their household members. In positive tested individuals, antibody response is monitored quarterly for one year. Untested and negative participants receive the screening questionnaire every four weeks until gauged as possible incident cases or till the study end.Originated from a collaboration between researchers and community stakeholders, the CHRIS COVID-19 study aims at generating knowledge about the epidemiological, molecular, and genetic characterization of COVID-19 and its long-term sequelae.

Determinants of SARS-CoV-2 nasopharyngeal testing in a rural community sample susceptible of first infection: the CHRIS COVID-19 study

“…First, most information was self-reported, thus some reporting error could not be excluded. Even if individuals were randomly selected by stratification and the analyses accounted for population-representative weights, some selection bias cannot be excluded, although we counteracted it by applying relative sample weights stratified by the age and sex distribution of the target population(4,20). Second, we did not consider availability of and distance to testing sites, which may affect the chance to undergo a test(29).…”

“…The probability of undergoing a swab test was assessed against characteristics collected in baseline and follow-up questionnaires: a) biological characteristics: age, sex, and body mass index (BMI); b) any pre-existing pathologies (more details in the Supplementary Material ); c) lifestyle determinants: smoking status; d) socio-demographic characteristics: educational qualification, main occupation, and crowding index (ratio between number of cohabitants and number of rooms in the house as a measure of household living conditions); e) information reflecting individual symptomatology, close contacts with infected or symptomatic individuals defined as permanence within the same indoor environment for at least 15 minutes at a distance of less than 2 meters without protection or direct physical contact with another person, and SARS-CoV-2 vaccination status(20).…”

“…The CHRIS COVID-19 study (20), a longitudinal study embedded within the Cooperative Health Research In South Tyrol (CHRIS) study (21), was established on July 13, 2020 to assess the determinants of SARS-CoV-2 infection and COVID-19 disease. From all the 13,393 CHRIS participants, 1,812 individuals were randomly selected to represent the general adult population of the Val Venosta/Vinschgau district, based on age and sex distribution (20).…”

“…The CHRIS COVID-19 study (20), a longitudinal study embedded within the Cooperative Health Research In South Tyrol (CHRIS) study (21), was established on July 13, 2020 to assess the determinants of SARS-CoV-2 infection and COVID-19 disease. From all the 13,393 CHRIS participants, 1,812 individuals were randomly selected to represent the general adult population of the Val Venosta/Vinschgau district, based on age and sex distribution (20). By August 28, 2020, all selected individuals were invited to a baseline assessment consisting of a Roche Elecsys® Anti-SARS-CoV-2 assay serum antibody (SAb) test, a swab real time polymerase chain reaction (PCR) test, and a screening questionnaire.…”

“…Understanding to which extent COVID-19 testing probability may be driven by general or personal conditions is key not only to obtain unbiased epidemiological estimates but, most importantly, to evaluate public health interventions and resource allocation. To assess this question we exploited data collected in the context of a longitudinal population-based study on COVID-19 conducted in this rural Alpine region and characterized by repeated surveys to study participants every four weeks for the entire duration of the study (20). Individual determinants comprised biological, health, behavioral, cultural, and socio-economic aspects.…”