ABSTRACT
ObjectivesTo establish whether there is any change in mortality associated with infection of a new variant of SARS-CoV-2 (VOC-202012/1), first detected in UK in December 2020, compared to that associated with infection with circulating SARS-CoV-2 variants. DesignMatched cohort study. Cases are matched by age, gender, ethnicity, index of multiple deprivation, lower tier local authority region, and sample date of positive specimen, and differing only by detectability of the spike protein gene using the TaqPath assay - a proxy measure of VOC-202012/1 infection. SettingUnited Kingdom, Pillar 2 COVID-19 testing centres using the taqPath assay. Participants54,773 pairs of participants testing positive for SARS-CoV-2 in Pillar 2 between 1st October 2020 and 29th January 2021. Main outcome measures - Death within 28 days of first positive SARS-CoV-2 test. ResultsThere is a high probability that the risk of mortality is increased by infection with VOC-202012/01 (p <0.001). The mortality hazard ratio associated with infection with VOC-202012/1 compared to infection with previously circulating variants is 1.7 (95% CI 1.3 - 2.2) in patients who have tested positive for COVID-19 in the community. In this comparatively low risk group, this represents an increase of deaths from 1.8 in 1000 to 3.1 in 1000 detected cases. ConclusionsIf this finding is generalisable to other populations, VOC-202012/1 infections have the potential to cause substantial additional mortality over and previously circulating variants. Healthcare capacity planning, national and international control policies are all impacted by this finding, with increased mortality lending weight to the argument that further coordinated and stringent measures are justified to reduce deaths from SARS-CoV-2.
Subject(s)
Sleep Deprivation , COVID-19ABSTRACT
The serial interval of an infectious disease, commonly interpreted as the time between onset of symptoms in sequentially infected individuals within a chain of transmission, is a key epidemiological quantity involved in estimating the reproduction number. The serial interval is closely related to other key quantities, including the incubation period, the generation interval (the time between sequential infections) and time delays between infection and the observations associated with monitoring an outbreak such as confirmed cases, hospital admissions and deaths. Estimates of these quantities are often based on small data sets from early contact tracing and are subject to considerable uncertainty, which is especially true for early COVID-19 data. In this paper we estimate these key quantities in the context of COVID-19 for the UK, including a meta-analysis of early estimates of the serial interval. We estimate distributions for the serial interval with a mean 5.6 (95% CrI 5.1-6.2) and SD 4.2 (95% CrI 3.9-4.6) days (empirical distribution), the generation interval with a mean 4.8 (95% CrI 4.3-5.41) and SD 1.7 (95% CrI 1.0-2.6) days (fitted gamma distribution), and the incubation period with a mean 5.5 (95% CrI 5.1-5.8) and SD 4.9 (95% CrI 4.5-5.3) days (fitted log normal distribution). We quantify the impact of the uncertainty surrounding the serial interval, generation interval, incubation period and time delays, on the subsequent estimation of the reproduction number, when pragmatic and more formal approaches are taken. These estimates place empirical bounds on the estimates of most relevant model parameters and are expected to contribute to modelling COVID-19 transmission.
Subject(s)
COVID-19 , Sialic Acid Storage Disease , Communicable DiseasesABSTRACT
We describe regional variation in the reproduction number of SARS-CoV-2 infections observed using publicly reported data in the UK, with a view to understanding both if there are clear hot spots in viral spread in the country, or if there are any clear spatial patterns. We estimate that the viral replication number remains slightly above 1 overall but that its trend is to decrease, based on case data up to the 8 April. This suggests the peak of the first wave of COVID-19 patients is imminent. We find that there is significant regional variation in different regions of the UK and that this is changing over time. Within England currently the reproductive ratio is lowest in the Midlands (1.11 95% CI 1.07; 1.14), and highest in the North East of England (1.38 95% CI 1.33-1.42). It remains unclear whether the overall reduction in the reproductive number is a result of social distancing measures, due to the long and variable time delays between infection and positive detection of cases. As we move forwards, if we are to prevent further outbreaks, it is critical that we can both reduce the time taken for detection and improve our ability to predict the regional spread of outbreaks