COVID-19 within a large prison with high number of vulnerable adults in the UK, March to June 2020: an outbreak investigation and screening event

Wilburn, Jennifer; Blakey, Eleanor; Trindall, Amy; Burr, Helen; Tanti, Vince; Doolan, Sue; Palmer, Ian; Jewell, Tony; Balakrishnan, Ravikumar

OBJECTIVE: To describe the public health response to COVID-19 within a large prison with a high number of clinically vulnerable residents. DESIGN: An outbreak investigation was undertaken among all residents and staff. A screening event involved nose and throat swab samples from residents and staff that were examined by polymerase chain reaction (PCR). An electronic questionnaire regarding risk factors was distributed to staff. RESULTS: 58 residents out of 1,156 (5.0%, 95% CI: 3.8 – 6.3) and 129 staff out of 510 (25.3%, 95% CI: 21.5 – 29.1) displayed COVID-19 symptoms, including six and eight confirmed, respectively. Residents reported symptoms of cough with no fever (29.3%), followed by a cough and fever (15.5%). 62.1% of symptomatic residents were 50 years or older, placing them in the group at risk for severe COVID-19 disease. Wing I had the highest attack rate (12.5%). 1,063 individuals were swabbed during the 5-day screening event, and all had negative swab results. CONCLUSION: The findings were consistent with the hypothesis of a propagating outbreak with decreasing incidence since the peak date of onset. COVID-19 transmission within a high-risk setting was quickly contained and an explosive outbreak prevented through a multi-agency public health response.