Covid Situation Report: Sep 26, 2024
Update on Covid providing information on prevalence and hospital admissions for England and its regions. This post is best viewed using the browser or Substack app.
Introduction.
This report is part of a weekly series that summarises the Covid situation in England and its regions.
A reminder that not all of the data previously included in the situation update is now available on a weekly basis. Where relevant, changes to the content and data sources have been noted.
This week's report contains data on weekly Covid hospital admissions from the UKHSA surveillance report, which is now released biweekly. This week also saw the monthly daily hospital data from NHS England published. Additionally, the report includes case rates from the UKHSA Covid dashboard and the latest available data for Scotland, Wales and Northern Ireland.
Summary.
This week's data shows a mixed picture with Covid levels increasing in both England and Wales. However, hospital data for Scotland indicates that levels are stable. Northern Ireland's data for this week has yet to be published.
Over the past two weeks, the Covid test positivity rate in England has risen significantly to 11.8% with the fastest rise in the oldest age group. Hospital admission rates have also risen significantly.
In addition, case rates for England have started to rise across all regions in the past week.
In Scotland, hospital admissions and the number of beds occupied by Covid patients have stopped falling but have remained stable in the past week.
In the past week, Covid cases and hospital admissions in Wales have both increased significantly.
Northern Ireland’s hospital admissions for community-acquired Covid has not yet been published so there is no update available.
This is an important reminder that Covid is not presently a seasonal disease and may never become one. As such, we should anticipate potential future waves with the emergence of new variants and as immunity levels diminish.
With that in mind, the NHS have reconfirmed eligibility criteria for the Autumn 2024 booster campaign which will start on October 3, 2024 and bookings are now open to the public. Eligibility can be confirmed and bookings made at the following link.
As always, it’s important to remember that the risk of hospitalisation from Covid infection increases significantly with age and for those immunocompromised. Also Long Covid remains a risk for all as shown by the recent ONS report. Therefore, it is prudent to take appropriate measures such as self-isolating when experiencing Covid symptoms and enhancing ventilation or wearing masks whenever possible.
Status of main respiratory diseases in England.
This section starts with the latest available data on positivity rates for primary respiratory infections in England. It is important to understand that positivity differs from prevalence, which refers to the overall percentage of COVID-19 in the general population. Appendix 1 provides a more detailed explanation of the difference and why positivity rates are a useful indicator of trends in Covid infection levels.
The chart below displays the test positivity rates for the main respiratory illnesses in England, including Flu, Covid, RSV, and Rhinovirus.
The recent falls in the Covid positivity rate from the summer peak has stopped and in the past two weeks there have been significant increases in the rate. Meanwhile, the flu positivity rate remains significantly lower than that of Covid. Additionally, RSV rates have dropped to very low levels, but Rhinovirus rates have seen large increase.
The next chart shows the trend for Covid positivity rate by age. Hover your cursor over one of the chart lines to display the positivity rate for all ages. For comparison the grey line shows the positivity rate for all age groups.
The test positivity rate has stopped falling from the summer peak in all age groups and has started to increase for most ages. In particular, there is a significant rise in those aged 65 and older who continue to have the highest rate. However, it's important to note that most tests are currently performed on hospital patients, who tend to be older as they are more susceptible to hospitalisation due to Covid.
The final chart in this section shows weekly hospital admissions per 100,000 people in England for the main respiratory diseases.
Consistent with the test positivity rate data, the past two weeks have seen weekly hospital admission rates for Covid increasing significantly. Note that hospital admission data for Flu and RSV is not currently published.
Although age-specific data for hospital admissions are no longer released, earlier statistics on Covid hospital admissions and the current test positivity rates by age indicate that the rise in hospitalizations will primarily impact the over 65 year olds.
It's important to note that while testing policies have been updated from April 1, 2024, the guidelines for testing patients showing Covid symptoms or when a positive result would change the patient's treatment remained unchanged. Consequently, the number of Covid hospital admissions should be a dependable indicator of the virus's prevalence in the community for the period shown in these charts.
Covid case rates in England
The UKHSA Covid dashboard continues to publish daily case rates for England on a weekly basis. As the majority of testing now occurs in hospitals or under medical supervision, these rates should closely align with hospital admissions. However, a comparison of daily case rates and daily admissions shows that this is not the case.
Appendix 1 indicates that although Covid case rates typically reflect the pattern of hospital admissions, there is a notable discrepancy in the magnitude of changes, with admissions experiencing a more pronounced fluctuation than case rates. Therefore, while case rates are helpful in signalling the general trend of Covid within the population, they do not precisely represent the degree of change.
The first chart in this section shows daily case rate per 100,000 individuals.
The chart indicates that Covid case rates have stopped falling and, after a period of stability, are starting to rise significantly. Current case rates are now higher than observed during the peak in May. It is important to note, as detailed above and in Appendix 1, that comparisons with the peak in Winter 2023 are not recommended.
The next panel chart in this section shows Covid rates for the regions of England. Hover your cursor over one of the chart lines to display the admission rates for all regions.
The panel charts indicate that in the past week daily case rates across all regions have started to rise .
Daily Covid hospital admissions and bed occupancy.
This section gives a more detailed examination of the most recent daily Covid data for hospitals in England.
NHS England stopped the weekly publication of data used to create these dashboards from April 4, 2024 and have moved to a monthly publication schedule. The next update will be available on October 10, 2024 covering September data
Scotland weekly hospital admissions and bed occupancy
Scotland continues to publish weekly data on hospital admissions and bed occupancy for Covid as well as waste water monitoring data. The dashboard for Scotland’s data can be accessed here.
The following panel chart shows the most recent data for weekly Covid hospital admissions up to Sep 15, depicted in blue, together with the number of beds occupied by Covid patients up to Sep 22, shown in orange. The number of occupied beds represent patients being treated for Covid as well as those being treated with Covid.
The charts shows that the recent 'summer' Covid wave in Scotland has led to more hospital admissions and a greater number of beds occupied by Covid patients compared to the 'winter' wave. This contrasts with England, where 'summer' hospital admissions did not surpass those seen in 'winter'.
The recent fall in weekly Covid admissions and bed occupancy for Scotland has now stopped and has again remained unchanged this week, albeit at higher levels than earlier in the year.
Scotland remains the only home nation that is monitoring Covid levels using wastewater sampling. However, wastewater data reporting is currently paused until the end of September as the responsibility for laboratory Covid water sample testing transfers from Scottish Environment Protection Agency (SEPA) to NHS Lothian.
Wales Covid cases and hospital admissions.
Public Health Wales publishes a weekly Covid dashboard, presenting key Covid hospital indicators for the preceding 90 days. This dashboard can be found here. Additionally, data regarding Covid cases detected through testing in hospitals and other medical facilities are released every week.
The following chart presents the latest data for the weekly number of cases reported.
The summer wave of cases in Wales exceeded the 'winter' wave, culminating in the highest level in more than a year. Although this surge is over the recent fall in Covid cases in Wales has stopped and are now starting to rise once again.
The following chart gives the trend for weekly hospital admissions in Wales.
Hospital admissions for Covid are following the same trend as cases and, after falling from the summer peak, are now starting to increase significantly.
Northern Ireland hospital admissions
Public Health Northern Ireland publishes a weekly COVID-19 Epidemiological Bulletin that provides data on Covid cases, hospital admissions and occupancy and care home incidents. The full report, published every Thursday, can be found here.
Northern Ireland’s hospital admissions for community-acquired Covid has not yet been published so there is no update available at present.
In conclusion
Although the amount of data currently being published has decreased, the information available for England show that Covid levels are now rising quickly following the fall after the summer peak.
Data from Scotland, Wales, and Northern Ireland indicate that the recent 'summer' wave of Covid-19 had higher infection levels than the 'winter' wave. While levels have decreased since the summer peak, they are now increasing in Wales. However, Scotland levels remain stable albeit higher than earlier in the year.
As always, if you have any comments on this Covid Situation Report or suggestions for topics to cover, please post a message below.
Appendix 1. Test positivity rates and prevalence
Positivity rates are derived from the results of hospital laboratory tests conducted on patients exhibiting symptoms of respiratory diseases. Test positivity is the percentage of patients who test positive for Covid of the total number of patients tested. Since the individuals tested for this measure are not a representative sample of the general population it differs from prevalence, which is derived from a representative sample of the population.
Test positivity rates, while not directly estimating the number of Covid infections in the general population, can be a valuable indicator of the infection trend. The panel chart below compares the weekly test positivity rate among hospital patients with respiratory symptoms to the prevalence of Covid in the general population, as reported in the Winter Infection Survey.
The chart shows that the weekly test positivity rates for patients with symptoms of respiratory infections follows the same pattern as the prevalence for Covid reported by the Winter Infection Survey. Since the Winter Infection Survey is based on a representative sample of the general population this supports using test positivity as a useful proxy for infection trends.
Appendix 2. How reliable are Daily Covid Case Rates?
The UKHSA Covid dashboard continues to publish daily case rates for England on a weekly basis. As the majority of testing now occurs in hospitals or under medical supervision, these rates should be closely aligned with hospital admissions and the positivity rate of tests.
The first panel chart in this section tests that assumption by comparing the daily case rate per 100,000 individuals, shown in red, with daily hospital admissions for Covid reported by NHS England, depicted in blue.
The chart shows that while Covid case rates generally mirror the pattern of Covid hospital admissions, there is a significant disparity in the scale of changes. The grey shaded areas on each chart highlights the difference between the peak of the winter wave and the recent peak in June. Case rates experienced a 64% decrease, whereas hospital admissions saw a reduction of only 32% between the winter and June peaks.
In conclusion, although case rates are useful for indicating the overall trend of Covid in the population, they do not accurately reflect the extent of change. The likely reason for this is that testing levels have decreased by about a half since January.
I can’t thank you enough for these weekly updates, Bob. They are invaluable.
🙏