ABSTRACT
In the early phases of the SARS coronavirus type 2 (SARS-CoV-2) pandemic, testing focused on individuals fitting a strict case definition involving a limited set of symptoms together with an identified epidemiological risk, such as contact with an infected individual or travel to a high-risk area. To assess whether this impaired our ability to detect and control early introductions of the virus into the UK, we PCR-tested archival specimens collected on admission to a large UK teaching hospital who retrospectively were identified as having a clinical presentation compatible with COVID-19. In addition, we screened available archival specimens submitted for respiratory virus diagnosis, and dating back to early January 2020, for the presence of SARS-CoV-2 RNA. Our data provides evidence for widespread community circulation of SARS-CoV-2 in early February 2020 and into March that was undetected at the time due to restrictive case definitions informing testing policy. Genome sequence data showed that many of these early cases were infected with a distinct lineage of the virus. Sequences obtained from the first officially recorded case in Nottinghamshire - a traveller returning from Daegu, South Korea - also clustered with these early UK sequences suggesting acquisition of the virus occurred in the UK and not Daegu. Analysis of a larger sample of sequences obtained in the Nottinghamshire area revealed multiple viral introductions, mainly in late February and through March. These data highlight the importance of timely and extensive community testing to prevent future widespread transmission of the virus.
Subject(s)
COVID-19/diagnosis , COVID-19/virology , Respiratory System/virology , SARS-CoV-2/isolation & purification , Adult , Aged , COVID-19/epidemiology , COVID-19/transmission , COVID-19 Nucleic Acid Testing , Female , Humans , Male , Mass Screening/methods , Middle Aged , Phylogeny , RNA, Viral/genetics , Retrospective Studies , SARS-CoV-2/genetics , United Kingdom/epidemiologyABSTRACT
A pandemic such as COVID-19 can cause a sudden depletion of the worldwide supply of respirators, forcing healthcare providers to reuse them. In this study, we systematically evaluated dry heat treatment as a viable option for the safe decontamination of N95 respirators (1860, 3M) before their reuse. We found that the dry heat generated by an electric cooker (100 degrees C, 5% relative humidity, 50 min) effectively inactivated Tulane virus (TV, >5.2-log(10) reduction), rotavirus (RV, >6.6-log10 reduction), adenovirus (AdV, >4.0-log(10) reduction), and transmissible gastroenteritis virus (TGEV, >4.7-log(10) reduction). The respirator integrity (determined on the basis of the particle filtration efficiency and quantitative fit testing) was not compromised after 20 cycles of a 50 min dry heat treatment. On the basis of these results, dry heat decontamination generated by an electric cooker (e.g., rice cookers, instant pots, and ovens) could be an effective and accessible decontamination method for the safe reuse of N95 respirators. We recommend users measure the temperature during decontamination to ensure the respirator temperature can be maintained at 100 degrees C for 50 min.