A large outbreak of COVID-19 in a UK prison, October 2020 to April 2021.

Prisons are susceptible to outbreaks. Control measures focusing on isolation and cohorting negatively affect wellbeing. We present an outbreak of coronavirus disease 2019 (COVID-19) in a large male prison in Wales, UK, October 2020 to April 2021, and discuss control measures.We gathered case-information, including demographics, staff-residence postcode, resident cell number, work areas/dates, test results, staff interview dates/notes and resident prison-transfer dates. Epidemiological curves were mapped by prison location. Control measures included isolation (exclusion from work or cell-isolation), cohorting (new admissions and work-area groups), asymptomatic testing (case-finding), removal of communal dining and movement restrictions. Facemask use and enhanced hygiene were already in place. Whole-genome sequencing (WGS) and interviews determined the genetic relationship between cases plausibility of transmission.Of 453 cases, 53% (n = 242) were staff, most aged 25-34 years (11.5% females, 27.15% males) and symptomatic (64%). Crude attack-rate was higher in staff (29%, 95% CI 26-64%) than in residents (12%, 95% CI 9-15%).Whole-genome sequencing can help differentiate multiple introductions from person-to-person transmission in prisons. It should be introduced alongside asymptomatic testing as soon as possible to control prison outbreaks. Timely epidemiological investigation, including data visualisation, allowed dynamic risk assessment and proportionate control measures, minimising the reduction in resident welfare.

Dry cotton or flocked respiratory swabs as a simple collection technique for the molecular detection of respiratory viruses using real-time NASBA.

This paper describes the molecular detection of influenza A, influenza B, respiratory syncytial virus and human metapneumovirus using real-time nucleic acid sequence based amplification (NASBA) from respiratory samples collected on simple dry cotton swabs, non-invasively and in the absence of transport medium. Viral RNA was detectable on dry cotton and flocked swabs for at least 2 weeks at room temperature and was readily extracted using magnetic silica extraction methods. Dry cotton respiratory swabs were matched with traditionally collected respiratory samples from the same patient, and results of traditional laboratory techniques and real-time NASBA were compared for all four viral targets. The results not only showed a significant increase in the detection rate of the viral targets over traditional laboratory methods of 46%, but also that dry swabs did not compromise their recovery. Over two subsequent winter seasons, 736 dry cotton respiratory swabs were collected from symptomatic patients and tested using real-time NASBA giving an overall detection rate for these respiratory virus targets of 38%. The simplicity of the method together with the increased detection rate observed in the study proves that transporting a dry respiratory swab to the laboratory for respiratory virus diagnosis using molecular methods is a suitable and robust alternative to traditional sample types.