Study of the Spread of COVID-19 in Saint Petersburg, Russia

Study Overview
=================
Brief Summary
-----------------
Seroprevalence study of COVID-19 in Saint Petersburg, Russia is a regional longitudinal cohort study aiming to evaluate the spread dynamics of the COVID-19 disease in the population of Saint Petersburg. Clinically asymptomatic adults are sampled from the population using random digit dialing and tested for the presence of SARS-CoV-2-specific antibodies in the blood serum. Data collection and serial sampling of the same individuals spans four weeks and is conducted every two weeks in order to understand both the spread of the virus in the population.

Detailed Description
-----------------
At least 1 000 individuals, 18 years old and older, are randomly sampled using random digit dialing from the population of Saint Petersburg, Russia. Random sampling is performed by a survey company on the list of mobile phone numbers with designated geography prefixes of St. Petersburg. The baseline questionnaire for computer-assisted telephone interview includes travel history, medical history, and socio-economic status of the respondents. Sampled individuals are then invited to the clinic for blood sampling, their refusal to participate is recorded. Collected blood samples are used for SARS-CoV-2-specific antibodies testing. Data and sample collection spans four weeks and is conducted every two weeks. Participants complete additional questionnaires in the clinic providing information on medical history, history of allergies, chronic disease, smoking, and medication taken regularly. Contact tracing data and environmental conditions of the household are reсorded.

Official Title
-----------------
A Population-Based Seroprevalence of SARS-CoV-2-Specific Antibodies Among Adults in Saint Petersburg, Russia: Longitudinal Cohort Study

Conditions
-----------------
COVID19

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Individuals sampled from the population of Saint Petersburg, Russia using random digit dialling. Subjects aged 18 and older of both genders. Asymptomatic at the time of blood draw. Written informed consent for a blood draw, SARS-COV-2 antibody test, and data collection. Exclusion Criteria: Presence of fever or cough or respiratory distress at the time of blood test not attributable to other known chronic disease. Age under 18. Any health condition that may be a contraindication towards blood sampling in out-patient clinic. Residence in Kolpinskiy, Kurortniy, Krasnoselsky, Kronshtadtskiy, Petrodvorcoviy, Pushkinskiy districts of St. Petersburg.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Healthy adults<br>Healthy adults randomly sampled from the population of Saint Petersburg | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Prevalence of the SARS-COV-2 infection in Saint Petersburg, Russia | Measured by SARS-CoV-2-specific antibodies serial testing and corrected for volunteer bias and test characteristics. | Measured with two-week (14 days) intervals | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Prevalence odds ratios | Comparison of prevalence by age, sex and socioeconomic strata. | Measured with two-week (14 days) intervals | 
| Immune response dynamics | Seropositivity, seroreversion and seroconversion. | Measured with two-week (14 days) intervals | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
seroprevalence, covid-19, sars-cov-2