A report about the experience of COVID-19 active surveillance of homeless, undocumented people, and shelter staff in two cities of Lazio, Italy.

OBJECTIVE: This study aimed to investigate COVID-19 spread among people experiencing homelessness (PEH), undocumented migrants (UMs), and shelter staff of homeless service sites. Another aim has been to prevent an outbreak among these populations. A San Gallicano Institute's initiative to sustain the health system in helping hard-to-reach populations, very often with no community medical care coverage. SUBJECTS AND METHODS: The San Gallicano Dermatological Institute performed active surveillance for COVID-19 on PEH and UMs living in Rome and Latina, Italy. The screening was performed with two swabs: real-time polymerase chain reaction (RT-PCR) and antigen rapid tests. RESULTS: From June 2020 to January 2022, we performed 10,651 tests: 5,442 molecular swabs and 5,209 antigen rapid tests. A total of 3,503 individuals were screened. The prevalence of SARS-CoV-2 infection was 2.9% among the health and social workers and 5.7% among PEH and UMs. None of the people positive for COVID-19 had symptoms or signs of several illnesses. PEH and UMs who tested positive for COVID-19, asymptomatic or pauci-symptomatic, were transferred to a COVID Hotel or dedicated apartment for further clinical monitoring. CONCLUSIONS: People experiencing homelessness and undocumented migrants are often not registered in the National Health Service and, therefore, difficult to trace. These data could aid in estimating the spread of SARS-CoV-2 among people experiencing homelessness, undocumented migrants, and shelter staff in two Italian cities.