Clinical trial NCT04376996: Slovenian National COVID-19 Prevalence Study
Official title: Slovenian National COVID-19 Prevalence Study
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: COVID-19
SARS-CoV-2
Lead sponsor: University of Ljubljana
Sponsor class: OTHER
First posted: 2020-05-06
Enrollment: 3000
Sex: ALL
Standard ages: CHILD
ADULT
OLDER_ADULT
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: 3,000 inhabitants randomly selected from the Slovenian general population. Sample is representative in age, gender, and geographical distribution.

Brief summary: The investigators are conducting a national COVID-19 prevalence survey on a sample of 3,000 inhabitants that were randomly selected from the Slovenian population. The sample is representative in age, gender, and geographical distribution.

The main objective is to assess how many people in Slovenia have COVID-19 in April/May 2020 and how many were infected with SARS-CoV-2 previously.

The investigators are using a direct detection of SARS-CoV-2 RNA in nasopharyngeal samples with validated two-target PCR-based commercial assay. For a serological response to the etiological agent, IgG and IgA anti-SARS-CoV-2 antibodies are measured in plasma samples using a validated commercial assay.

Detailed description: The investigators are conducting a national COVID-19 prevalence survey on a sample of 3,000 inhabitants that we have randomly selected from the Slovenian population. The sample is representative in age, gender, and geographical distribution.

The main objective is to assess how many people in Slovenia have COVID-19 in April/May 2020 and how many were infected with SARS-CoV-2 previously.

Direct detection of SARS-CoV-2 RNA in nasopharyngeal samples is performed with validated two-target PCR-based commercial assay. For a serological response to the etiological agent, IgG and IgA anti-SARS-CoV-2 antibodies are measured in plasma samples using a validated commercial assay.

Principal aims of the study are to systematically and accurately assess:

* How many people in Slovenia are actively infected with SARS CoV-2 in April/May 2020?
* How many are asymptomatic and do not even know they are or were infected?
* How many people in Slovenia have contacted SARS-CoV-2 and already have COVID-19 until mid May 2020?

The study is carried out by the Institute of Microbiology and Immunology of University of Ljubljana. The Institute is Slovenia's leading institution for microbiology and immunology research. The study is joined by a team of IT specialists, data scientists, and statisticians from the other departments of the University of Ljubljana.

To speed-up and support the study, an innovative information infrastructure for data gathering and management was purposely developed and optimized for the study. The system fosters error-free data collection, automatic processing of questionnaires using artificial intelligence approaches, and provides security for sensitive clinical data.

All participants will be passively followed up twice monthly and tested again for the presence of anti-SARS-CoV-2 antibodies in plasma samples six months after enrollment.

Eligibility criteria: Inclusion Criteria:

Signed informed consent only.

Exclusion Criteria:

Declined participation, no response on study invitation, no samples collected.

Primary outcomes:
measure: Prevalence of SARS-CoV-2 RNA in nasopharyngeal samples
timeFrame: April to May 2020
measure: Prevalence of anti-SARS-CoV-2 antibodies in blood samples
timeFrame: April to November 2020
Secondary outcomes:
Other outcomes:
Locations:
city: Ljubljana
country: Slovenia
facility: University of Ljubljana
Study officials:
affiliation: Univesity of Ljubljana, Slovenia
name: Mario Poljak, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Maver Vodicar P, Ostrbenk Valencak A, Zupan B, Avsic Zupanc T, Kurdija S, Korva M, Petrovec M, Demsar J, Knap N, Strumbelj E, Vehovar V, Poljak M. Low prevalence of active COVID-19 in Slovenia: a nationwide population study of a probability-based sample. Clin Microbiol Infect. 2020 Nov;26(11):1514-1519. doi: 10.1016/j.cmi.2020.07.013. Epub 2020 Jul 18.
citation: Poljak M, Ostrbenk Valencak A, Strumbelj E, Maver Vodicar P, Vehovar V, Resman Rus K, Korva M, Knap N, Seme K, Petrovec M, Zupan B, Demsar J, Kurdija S, Avsic Zupanc T. Seroprevalence of severe acute respiratory syndrome coronavirus 2 in Slovenia: results of two rounds of a nationwide population study on a probability-based sample, challenges and lessons learned. Clin Microbiol Infect. 2021 Jul;27(7):1039.e1-1039.e7. doi: 10.1016/j.cmi.2021.03.009. Epub 2021 Apr 7.