SCREENING AND SEROEPIDEMIOLOGY OF SARS-CoV-2 INFECTION AT THE UNIVERSITY OF BARCELONA: A CROSS-SECTIONAL STUDY

BACKGROUND: On January 7, 2020, the Chinese authorities identified as the agent responsible for the cases of atypical pneumonia of unknown etiology a new type of virus of the Coronaviridae family that has subsequently been named SARS-CoV-2, whose genetic sequence was shared by Chinese authorities on January 12 (taxonomy ID: 2697049).

On January 30, 2020, the director general of the World Health Organization (WHO), following the advice of the Emergency Committee convened in accordance with the International Health Regulations (2005), declared that the COVID-19 outbreak started in Wuhan, China in December 2019, being a public health emergency of international concern. On March 11, the WHO declared the global SARS-CoV-2 pandemic.

So far, in the absence of effective vaccines or antiviral drugs, efforts have focused on identifying cases and their contacts. Both the cases and their contacts are isolated for about 14 days with the intention of minimizing the spread of this infection and avoiding an increase in the number of affected.

At the level of microbiological clinical practice, the diagnosis of SARS-CoV-2 infection can be made by:

1. Detection of the presence of the target nucleic acid sequences in the RNA of SARS-CoV-2 (RdRP gene of SARSCoV-2 and gene N and Orf1ab present in SARS and SARSCoV-2, gene E of SARS) in the Patient specimen by reverse transcriptase polymerase chain reaction (RT-PCR).
2. Detection of antibodies: total immunoglobulins and IgG.

At the time of writing this new version of the protocol, the country is immersed in the second wave of the COVID-19 pandemic. The projections of the natural history of the disease and the estimates of possible infections by SARS-CoV-2, carried out at the end of the first wave, made it possible to determine the feasibility of this second wave with the onset of cold from the autumn. Some of the factors that supported this hypothesis are:

1. At the end of the first wave, herd immunity against the virus was not reached. The results of the ENE-COVID study, published in the Lancet magazine in July this year, indicated that in our environment only 6% have achieved immunity.
2. Many respiratory viruses have a seasonal behavior and their circulation increases in the autumn and winter months. This is why a similar behavior was assumed in this new SARS-CoV-2 virus, experiencing greater transmissibility with the drop in temperature and increase in humidity, typical of winter periods.
3. Observing the evolution of the 1918 pandemic flu, the first wave was in 1918, but this was followed by a second and third wave, in 1919 and 1920 respectively. However, the second wave presented the peculiarity of being triggered in other areas where the first wave had not been so intense.

Given this scenario, the University of Barcelona, together with the Gerencia Territorial del Área Metropolitana Sud, has planned to carry out, a study of seroprevalence and screnning of SARS-CoV-2 in the population of UB users. The results of this study will help to make preventive decisions in the face of SARS-CoV-2 infection at the UB, in relation to its teaching and administrative activities. In addition, this cross-sectional study can serve as the base study for a future follow-up study.

HYPOTHESIS: The incidence of SARS-CoV-2 infection in the group of students and workers at the University of Barcelona is similar to the incidence in the general population.

The seroprevalence of SARS-CoV-2 infection in the group of students and workers at the University of Barcelona is similar to the seroprevalence of the general population.

MAIN OBJECTIVE

• Estimate the incidence of SARS-CoV-2 infection in the UB community.
• Estimate the SARS-CoV-2 seroprevalence infection in the UB community.

SECONDARY OBJECTIVES

Clinical objectives:

• Estimate the factors associated with the incidence in the UB community.
• Estimate the factors associated with seroprevalence in the UB community

STUDY DESIGN Cross-sectional study with epidemiological information to determine the incidence and prevalence of SARS-CoV-2 infection in the UB population, by PCR and serology tests to detect antibodies.