Assessment of SARS-CoV-2 infection through rapid serology testing in the homeless population in the City of Rome, Italy. Preliminary results

Ralli, Massimo; Cedola, Chiara; Urbano, Suleika; Latini, Ottavio; Shkodina, Natalia; Morrone, Aldo; Arcangeli, Andrea; Ercoli, Lucia

Background: The development of COVID-19 pandemic has affected all segments of the population; however, it had a significant impact on vulnerable subjects, such as in people experiencing homelessness. The aim of this study was to evaluate the prevalence of COVID-19 spread in homeless persons in the city of Rome, Italy. Design and Methods: Patients included in the study underwent a clinical evaluation and rapid antibody analysis on capillary blood for the presence of immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies to SARS-CoV-2 virus. Symptomatic patients were not included in the screening and immediately referred to local hospitals for further evaluation. Results: One-hundred seventy-three patients of both sexes were tested for SARS-CoV-2 infection through rapid serological test. Age range was 10-80 years; people came from 35 different countries of origin and 4 continents. Test results were negative for most patients (170-98.2%); two patients had positive IgM (1.2%) and one patient had positive IgG (0.6%). Conclusions: Our study is the first to evaluate the prevalence of SARS-CoV-2 infection in people experiencing homelessness in the city of Rome, Italy. Most patients were negative for COVID- 19, although several factors may have had an impact on this result, such as the exclusion of symptomatic patients, the limited sensitivity of rapid serological tests in the initial stage of infection and the prevention measures adopted in these populations. Larger studies on fragile populations are needed to prevent and intercept new clusters of infection in the upcoming months.