Covid Situation Report: Oct 10, 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. Finally, there are short updates on the XEC variant and the Autumn 2024 booster campaign.

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Summary.

This week's data shows a mixed picture with Covid levels increasing in both England and Wales. However, hospital data for Scotland and Northern Ireland indicate that levels are stable.

Whilst the Covid test positivity rate in England has not risen over the past two weeks hospital admission rates have risen to levels approaching the summer peak.

In addition, case rates for England have increased across most regions in the past week particularly in the Midlands and the North East,

In Scotland, hospital admissions and the number of beds occupied by Covid patients have stopped falling and have remained stable for several weeks albeit at levels higher than earlier in the year.

In the past week, Covid cases in Wales remained unchanged but hospital admissions increased significantly.

In Northern Ireland, the Covid test positivity rate has decreased slightly but remains relatively high, while hospital admissions have stayed stable.

Finally, new data on the prevalence of Covid variants in England show that XEC is starting to make progress and is likely to become dominant over the winter months.

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.

Worryingly, vaccine coverage has fallen with each successive seasonal Covid booster campaign and this years Autumn 2024 campaign will end earlier than than the previous year, on Friday, December 20.

With that in mind, the NHS have reconfirmed eligibility criteria for the Autumn 2024 booster campaign which started on October 3, 2024 and bookings are 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.

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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 significant increase in the Covid positivity rate has stopped and in the past two weeks has stabilised albeit at a relatively high level. 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 a large increase.

The next chart in this section shows weekly hospital admissions per 100,000 people in England for the main respiratory diseases. This week sees the return of admission rates for Flu and RSV.

Unlike the test positivity rate data, the past two weeks have seen weekly hospital admission rates for Covid continue to increase whilst admissions for Flu and RSV remain low.

From this week, UKHSA have restarted publishing age-specific data for weekly hospital admissions and the final chart in this section shows that the rise in admission rates for Covid is driven by patients 65 years and older. Hover your cursor over one of the chart lines to display the admission rates for all ages.

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.

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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 started rising again after a week of stability. 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 have started to rise again across most regions, particularly in the Midlands and North East regions.

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Daily Covid hospital admissions and bed occupancy.

Starting April 2024, NHS England moved from a weekly to a monthly publication schedule for daily Covid data in hospitals. This section provides an overview of the most recent data, released on September 12, which covered the month of August. As a result, it does not include the most recent weeks data used in the prior sections.

The following chart illustrates the daily number of Covid hospital admissions, including patients diagnosed with Covid after admission, for the year 2024 up to the end of September, in comparison with the full year data for 2023.

The data shows that hospital admissions for June and July of 2024 were higher that the figures recorded for the same months in 2023. Although there was a decline in admissions in August, this trend was reversed in September; however, the numbers still remained lower than those observed in 2023. It is noteworthy that the admissions in 2024 have yet to fall below the low seen in July 2023.

The final chart in this section shows the daily number of beds occupied by Covid patients in 2024 compared with 2023. The number of beds occupied by Covid patients includes both those being treated primarily for Covid and those ‘with’ Covid as a secondary infection. As a guide, about 25% of patients occupying these beds were being treated primarily for Covid in March 2024.

The data on hospital bed occupancy by Covid patients mirrors the pattern of Covid hospital admissions, corroborating the rise in admissions observed in September.

In summary, the daily Covid hospital admissions and occupied bed data indicate that the decline from the summer peak reversed at the end of August and increased throughout September. This is consistent with the UKHSA weekly admissions data and the daily case rates outlined in the preceding sections.

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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 as the responsibility for laboratory Covid water sample testing transfers from Scottish Environment Protection Agency (SEPA) to NHS Lothian.

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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. Despite last week's report indicating that the recent surge in cases might have peaked, this was not the case, and the levels over the past week have stabilised at moderately high levels.

The following chart gives the trend for weekly hospital admissions in Wales.

While Covid cases have remained stable this week, the number of hospital admissions for Covid is on the rise again, albeit lower than the figures reported last year.

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Status of main respiratory diseases in Northern Ireland.

This week, Public Health Northern Ireland began issuing a combined surveillance report on influenza, respiratory syncytial virus (RSV), and COVID-19 to offer a comprehensive view of the epidemiology of these infections within Northern Ireland. The new report, published every Thursday, can be accessed here.

The first chart in this section shows the test positivity rates in Northern Ireland for the main respiratory illnesses — Flu, RSV, and Covid.

The chart indicates that Covid levels have declined from the summer peak and have now stabilised, though they remain significantly higher than the rates of other respiratory viruses.

The chart below presents the weekly count of hospital admissions for the main respiratory illnesses where the infection was contracted in the community, thereby excluding patients who contracted Covid while in hospital. It is important to note that the hospital admissions data for other home nations include patients who contracted infections in the hospital, making them not directly comparable to the data from Northern Ireland.

The chart indicates that throughout much of 2024, the majority of hospital admissions related to respiratory infections were due to Covid. Following the summer peak, Covid admissions have declined and stabilised, yet they remain at a higher level than recorded earlier in the year.

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Variants update

While the new XEC variant has received considerable attention due to its higher growth advantage over other variants, no data on its prevalence in England have been published to date. However, this week UKHSA published data on the prevalence of variants in England that included XEC for the first time.

The chart below illustrates the prevalence of variants in sequenced cases up to the week ending Sep 22, 2024. For clarity, the various JN and FLiRT (KP) variants have been grouped into 'families'.

The chart indicates that FLiRT variants were dominant until September 22. However, even though it's still early, the XEC variant is beginning to demonstrate its growth advantage and will probably become dominant over the winter months.

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Covid Vaccination Levels in England

The Autumn 2024 Covid booster campaign started last week. Similar to previous booster campaigns, eligibility is restricted to those at the highest risk of hospitalisation and death. Those eligible are older people in care homes, individuals 65 years and older, the immunosuppressed. Eligibility can be checked and boosters booked at this link. In addition, health and care workers will be offered boosters through their employers.

Unlike previous Autumn campaigns that continued into February, this year's programme aims to complete vaccinations by Friday, 20 December 2024. However, vaccination outreach efforts will continue in underserved communities until 31 January 2025.

The chart below displays the coverage achieved by the end of each previous booster campaign, segmented by eligible age groups.

The chart shows that only the age group of 75 years and older has been eligible for all five booster campaigns to date. In addition, coverage at the end of the autumn campaigns is invariably higher compared to the spring campaigns. Finally, it is concerning that there has been a decrease in coverage with each subsequent spring and autumn campaign.

With the Autumn 2024 campaign ending earlier than the previous year, it is likely this pattern will continue, resulting in lower immunity levels in the elderly and other vulnerable groups.

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In conclusion

This week more data was made available although, regrettably, there are no indications that the ONS/UKHSA will run a Winter Infection Survey this year.

Although the amount of data currently being published has decreased, the information available for England show that Covid levels are now starting to rise again following the recent pause.

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, hospital admissions indicate they are now increasing in Wales. However, levels in Scotland and Northern Ireland 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.

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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.

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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.

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