Determining the prevalence and incidence of SARS-CoV-2 infection in prisons in England: a repeated panel survey & enhanced outbreak investigation (Preprint)

BACKGROUND: There are over 80,000 people imprisoned in England and Wales in 117 prisons. The management of the COVID-19 pandemic presents particular challenges in this setting where the confined, crowded and poorly ventilated conditions facilitate rapid spread of infectious diseases. OBJECTIVE: The COVID-19 in Prison Study (CiPS) aims to examine the epidemiology of SARS-CoV-2 in prisons in England in order to inform public health policy and practice during the pandemic and recovery. The primary objective is to estimate the proportion positive of SARS-CoV-2 infection in residents and in staff within the selected prisons. The secondary objectives include estimating the incidence rate of SARS-CoV-2 infection and examining how proportion positive and incidence rate vary among individual, institutional and system level factors. METHODS: The CiPS Phase 1 comprises a repeated panel survey of prison residents and staff in a representative sample of 28 prisons across England. All residents and staff in the study prisons are eligible for inclusion. Participants will be tested for SARS-CoV-2 using nasopharyngeal swab twice, six weeks apart. Staff will also be tested for antibodies to SARS-CoV-2. Phase 2 focuses on SARS-CoV-2 infection in prisons with recognised COVID-19 outbreaks. Any prison in England will be eligible to participate if an outbreak is declared. In three outbreak prisons, all participating staff and residents will be tested for SARS-CoV-2 antigens at three timepoints: as soon as possible after the outbreak is declared (day 0), seven days later (day 7) and at day 28. They will be swabbed twice: a nasal swab for lateral flow device testing and a nasopharyngeal swab for PCR testing. Testing will be done by external contractors. Data will also be collected on individual, prison level and community factors. Data will be stored and handled at the University of Southampton and PHE. Summary statistics will summarise the prison and participant characteristics. For the primary objective, simple proportions of individuals testing positive for SARS-CoV-2 and incidence rates will be calculated. Linear regression will examine the individual, institutional, system level and community factors associated with SARS-CoV-2 infection within prisons. RESULTS: The UK Government's Department for Health and Social Care funds the study. Data collection started on 20th July 2020 and will end on 31st May 2021. As of May 2021, we had enrolled 4,192 staff members and 6,496 imprisoned people in the study. Data analysis has started and we expect to publish initial findings in summer/autumn 2021. The main ethical consideration is the inclusion of prisoners, who are vulnerable participants. CONCLUSIONS: This study will provide unique data to inform the public health management of SARS-CoV-2 in prisons. Its findings will be of relevance to health policy makers and practitioners working in prisons.