Maela Tebon ^1* Ruth J. Davis ¹ Alessia Savoldi ¹ Nicola Soriolo ¹ Sarah E. Walters ¹ Michela Nose' ² Corrado Barbui ² Giulia Turrini ² Elisa Danese ³ Giuseppe Lippi ³ Riccardo Cecchetto ⁴ Annarita Mazzariol ¹ Davide Gibellini ¹ Gulser Caliskan ⁵ Pierpaolo Marchetti ⁵ Giuseppe Verlato ⁵ Andrea Princivalle ⁶ Stefano Porru ⁷ Evelina Tacconelli ¹ Pasquale De Nardo ¹

• ¹ Infectious Diseases Section, Department of Diagnostics and Public Health, University of Verona, Verona, Veneto, Italy
• ² Collaborating Centre for Research and Training in Mental Health and Service Evaluation, Department of Neuroscience, Biomedicine, and Movement Sciences, University of Verona, Verona, Veneto, Italy
• ³ Section of Clinical Biochemistry, Department of Neuroscience, Biomedicine, and Movement Sciences, University of Verona, Verona, Veneto, Italy
• ⁴ Microbiology Section, Department of Diagnostic and Public Health, Verona University, Verona, Veneto, Italy
• ⁵ Unit of Epidemiology and Medical Statistics, Department of Diagnostics and Public Health, University of Verona, Verona, Veneto, Italy
• ⁶ Section of Occupational Medicine, Department of Diagnostics and Public Health, University of Verona, Verona, Veneto, Italy
• ⁷ Section of Occupational Medicine, Department of Diagnostics and Public Health, University of Verona and Clinical Unit of Occupational Medicine, Integrated University Hospital of Verona, Verona, Italy

At the beginning of the COVID-19 pandemic, an ad hoc organisational framework was established between academic, local government and community partners to implement the "Sentinella -Identify, Trace and Prevent" screening programme in Verona, north-east Italy. Between September 2020 and May 2021, key populations not covered by any screening policies at the local and national level were screened for SARS-CoV-2. Target populations were: elderly residents (males > 65 years and females >75 years), bus and taxi drivers, social workers, supermarket employees, hospital cleaning and catering staff, researchers working in the local hospitals, students, and people experiencing homelessness (PEH). Five dedicated swab clinics, home testing facilities, and one mobile clinic were activated to collect nasopharyngeal swabs. Molecular analysis was performed for all the subjects; an antigen-rapid diagnostic test (Ag-RDT) was also implemented as a point-of-care test for PEH. Medical follow-up, psychological support, and quarantine facilities were organised for subjects who tested positive for SARS-CoV-2.Overall, 2075 subjects participated in the surveillance programme. Among these, 1572 were residents/workers, while 503 were PEH. A total of 127 (6.2%) participants tested positive for SARS-CoV-2. Sixty-nine were residents, 58 PEH. The incidence rate was 4 per 10.000 person/day (95% CI 3.1-5.0). The highest prevalence and incidence rates were found among supermarket employees (9.7% and 8.5 per 10.000 person/day, 95% CI 3.81-18.86, respectively), followed by hospital cleaning staff (8.1%, 7.6 per 10.000 person/day, CI 95% 4.9-11.7). Regarding PEH, the prevalence of SARS-CoV-2 was 11.5%. All PEH identified as positive were isolated in dedicated shelter facilities. Among the 69 residents/workers who were quarantined, 53 were reached for initial psychological support for assessing the presence of any psychological distress or psychiatric pathology. Among the subjects evaluated, 10 (18.9%) presented clinically significant psychological discomfort and accessed the stepped-care psychological intervention.The community partnerships played a pivotal role in optimising early case detection. Promotion of testing helped to prevent and contain more efficiently potential clusters through strategic planning, especially for PEH. Insights from the study highlight the importance of community partnerships in public health emergencies, particularly in the context of highly transmissible diseases pathways.