MRC Biostatistics Unit
We have published a new report on our real-time tracking of COVID-19.
Updated Findings
- The estimated number of new daily infections on 2nd December across England has increased substantially since our last publication to 183,000 (134,000–245,000, 95% credible interval) infections per day, corresponding to a national daily infection rate of 327 per 100k population. The highest rates are in London (GL) and the Midlands (Mids) (458 and 457 infections per 100k population respectively). All other regions are estimated to have rates below the national average, with the highest rates in the Northern regions (NW and NE, 293 and 279 new infections per 100K population, respectively) with the South East (SE) not far behind. The two regions with the lowest levels of infection still have rates that are higher than any region in our last publication. All estimates are, however, highly uncertain.
- We estimate the daily number of new diagnoses in hospitals to have hit a low on the 19th November. Since this time there has been an increase in the number of new diagnoses among patients admitted to hospital, with the estimate for December 2nd being in the range of 129–203, much higher than the 49–144 in our previous publication. The trend is set to continue such that by the 23rd December there are 198–425 new diagnoses among admissions to hospitals each day. At the current rate, admissions double in number every three weeks.
- The rate of growth of infections in England is 0.04 (0.02– 0.06) per day. This means that, nationally, the number of infections is increasing, corresponding to an Rt of around 1.30.
- In all regions the central estimate for Rt is greater than 1. The corresponding increase in infections appears fastest in GL and slowest in the East of England (EE). Though infections are increasing nationally, the regional picture is less certain and we present probabilities of 34% and 35% that the epidemic is actually declining in the South West (SW) and EE, respectively.
- Our estimates for the attack rate, the proportion of a population who have ever been infected, is up to 94.7% nationwide, and is now almost certainly over 90% in all regions. The estimated total number of infections to date (89.0m) far exceeds the size of the population of England, due to the presence of reinfections. On average people have experienced over 1.6 infections, though this will differ significantly by age.
- Note that the hospitalised diagnosis data used are only partially informative on Rt over the last two weeks. Therefore, the estimate for current incidence, Rt and the forecast of daily numbers of deaths are likely to be subject to significant revision.
Interpretation
Across England, we estimate that since around the 19th of November the daily number of diagnoses in hospitals has been increasing. PCR-positive infection prevalence is estimated to be most likely increasing in all NHS regions and in all age groups.
Currently Rt is above 1. Based on the periodicity of the Omicron waves and the degree of waning of immunity required to generate these waves, hospital admissions attributable to SARS-CoV-2 infection are anticipated to continue to rise for at least three further weeks beyond the end of the analysis presented here. The estimated levels of incidence represent a large increase from our previous published estimates, which was of 51k–99k infections per day on the 11th November. This estimate is now updated to 79k–88k, but the country has seen substantial growth since.
The Omicron variants have led to more than a tripling in the total number of infections. However, this has not translated into a proportionate increase in new diagnoses in hospitals, which have increased from 190k to 308k. Accordingly, since mid-September, we estimate a steep decline in the infection-hospitalisation ratio in younger age groups (and a less steep decline in older ages groups). This decline also coincides with a change to testing policy for new admissions. Therefore it is difficult to quantify the severity of the virus exactly as both reduced severity and reduced ascertainment will contribute to recent trends in IHR. Currently 0.14% of infections are detected in new admissions to hospital, with this figure rising to 1.1% in the over-75s.
Comment from lead researchers – Prof Daneila De Angelis & Dr Paul Birrell
Infection rates are increasing once again, and have been doing so now for a sufficiently long period that admissions to hospital due to SARS-CoV-2 infection are also on the increase. Indicators from the ONS COVID Infection survey also show rising prevalence. This wave of infection appears to be taking place very soon after the preceding wave, at a faster pace than the previous Omicron waves. Because of this our model suggests that the peak in infection cannot be too far away. The impact on hospital admissions will be lagged and, of course, everything is subject to substantial uncertainty. Reduced testing in hospitals, makes any signal in the data harder to detect. We will continue to monitor the pandemic development to capture any increases in infection as soon as they become apparent.”
Read full report: https://www.mrc-bsu.cam.ac.uk/now-casting/nowcasting-and-forecasting-13th-december-2022/