COVID-19: Cases rising across the UK

Last week our analysis of daily new COVID-19 cases highlighted 15 local authorities in England for whom, although they were not on the Public Health England watchlist at time of publication, the growth in new cases and/or the number of new cases had been high, and so were potentially of concern. Of the highlighted authorities, 8 subsequently appeared on last week’s watchlist, along with a further 5 areas. In the meantime, concern about rising case numbers has triggered new national restrictions, with gatherings being restricted to a maximum of 6 people across England and Scotland from Monday, with the other nations considering introducing similar restrictions. 
In this blog we explore the latest case numbers, with a view to likely changes to the PHE watchlist this Friday, as well as a view on the risks of heading towards a further national lockdown. In addition, we have expanded our analysis to include similar analysis for the other home nations, which highlights some of the drivers behind recent decisions.

The overall picture on case numbers

The chart below shows the latest case numbers published by the UK government (as at midday on 10th September). The bars show the daily numbers of new COVID-19 cases across the UK, with the line showing the running seven-day average, smoothing through dips in new case numbers which tend to happen at weekends.

The number of cases across the UK rose rapidly over March, as COVID-19 began to spread though the population.  Given testing capacity was very limited initially, it is likely that the ‘true’ infection numbers were much higher. After this initial surge subsided, daily case numbers fell over the summer, in part as the lockdown restrictions and social distancing measures help suppress transmission rates.

However, case numbers have been steadily increasing for the past few months. Over this period the testing capacity has been significantly higher than in the initial period, and able to be targeted around potential clusters. While the rate of increase is much slower than in the initial stages of the pandemic, there are concerns about the direction of travel, and the potential for further strain on medical services, and ultimately a rise in deaths.

The authorities have a difficult balancing act: aiming to suppress transmission rates as much as possible, while also not overly restricting everyday life, from a broader public health as well as financial perspective. The initial UK wide lockdown that was introduced at the end of March was clearly a fairly crude measure; using widespread restrictions to try to “slam on the brakes” for new infections and avoid overloading our critical care capacity. Some of these restrictions have been gradually lifted over recent months, at varying rates across the home nations, enabling schools to welcome back all children and some business to at least partially reopen. 

The focus has now switched to more localised approaches, with the intention of only putting in place restrictions in areas where, and for as long as, it is necessary. Whilst the virus remains with us, and case numbers are growing, the risk of a need to reimpose a wider, perhaps even national, form of lockdown remains. It is therefore vitally important that local authorities carefully monitor the case numbers, looking for signs that the virus may be becoming more prevalent, to enable them to take appropriate, focussed, localised action.

We examine below the available data on case numbers for local areas within in each of the home nations in turn, identifying areas which are at risk of requiring more localised action in the near future.

Case numbers in England

Public Health England publishes a weekly surveillance report exploring the national and local new COVID-19 cases data for England. One of the outputs of this surveillance is a “watch-list” of local authorities1 which are causing concern, split into three categories:

  • Intervention: These authorities have specific restrictions in place which are more limiting than those in place for England generally i.e. there is some form of local restriction (“lockdown”).
  • Enhanced Support: The local authority is gaining additional support and resources from central government, including increasing mobile testing capacity.
  • Concern: Highlighted as having high prevalence of COVID-19, the local authority is taking additional targeted actions in order to control COVID-19 case numbers. This can include additional testing in care homes and increased community engagement with high risk groups.

Last week we explored the then current watchlist, and set out 15 local authorities which we thought were at risk of joining the watchlist, due to either high (and statistically significant) growth in the weekly new cases and/or a case rate that was high compared to the national average. Of these authorities, 8 appeared on the latest watch list (along with a further 5 areas).

We have updated our analysis based on the latest data on cases, and highlight a number of areas which give cause for concern.

Week on week: A migration of authorities to growing new cases

A key characterising feature of the last week is that local authorities are generally further to the right, and higher up, on our case watch charts than they were last week. This can be seen in the graphic below – showing last week’s chart and this week’s chart side by side. (We have had to rescale the vertical axis from last week owing to the level of new cases now being seen in some areas.)

“It is concerning how the authorities are shifting to the right in this chart. We appear to be moving from a situation where very localised interventions are sufficient, to the new cases gaining momentum.”

We can see that, based on the latest data, a significant number of areas are what we would classify as ‘possible concern’ (the red dots). A total of 68 local authorities fall in this category, covering some 30% of the population of England. Combined with the 39 areas on the latest PHE watch list, around 47% of England is ‘at risk’. 

Focus on this week: Which local authorities might be of emerging concern?

We enlarge this week’s case watch below, and highlight a number of local authorities and groups of points of particular note.

The chart highlights several noteworthy points:

  • Bolton demonstrates why the PHE reversed the planned easing of restrictions in those areas in the face of high, and rapidly rising, new cases.
  • Birmingham saw a very large increase in weekly cases, to the extent that it is not shown on the chart (as it is beyond the limit of the horizontal axis). It seems likely that they will moved from the existing ‘Enhanced Support’ status to requiring direct Intervention in the very near future. Nearby Solihull is also causing concern, given relatively high increase in cases and case rate.
  • Similarly, two major northern cities (Sunderland and Liverpool) also appear likely to be requiring imminent interventions. Their adjacent areas are also seeing upticks in new cases, and high new case rates; Gateshead and Newcastle upon Tyne in the Tyneside area and Knowsley, St Helens, Wirral, Warrington in the Liverpool area.
  • High growth group (high cases): Several local authorities are categorised as a possible concern. Some of these have levels of new cases comparable to areas on the existing watchlist, and many are in the vicinity of existing areas of concern. These areas seem to be at strong risk of entering the PHE watchlist and receiving “concern” or “enhanced support” status and include Blaby (near Leicester), Broxtowe (near Nottingham), Hartlepool (near Middlesbrough which entered the watchlist last week), Hertsmere, Knowsley, Lincoln, Selby and Wolverhampton.
  • High growth group (cases closer to national rate): Many of the local authorities in the high growth group have relatively low new case rates – at or close to the national level (the cluster lower down in the red box in the chart). These authorities are showing as a possible concern due to a relatively high growth rate in those areas. The growth seen recently may be simply a localised outbreak in the area, or it may indicate more widespread growing community transmission. In these areas we imagine the local public health officials will be working closely with the local authority to identify the source of the growth in new cases.
  • While many of the previously identified areas of concern had been in and around the north of England, the latest data includes several authorities in the South East and South West, as well as some London boroughs. Any trend towards significant geographic spread in elevated case numbers is likely to increase the likelihood of further, potentially significant, restrictions at a national level.
  • Restrictions having the desired effect: In more welcome news, a number of areas on the PHE watch list have seen falls in case numbers more recently – suggesting the additional restrictions put in place have been having the desired effect of reducing rates of transmission in those areas. 

Case numbers in Scotland

Whereas England saw the first local restrictions introduced to Leicester at the end of June, the first local restrictions in Scotland were imposed in Aberdeen on 5th August. The restrictions in Aberdeen were recently lifted but restrictions have now been imposed in five areas, all in the wider Glasgow area. However, the phased easing of restrictions also mean greater national restrictions remain in place in Scotland than in England, for example on the opening of non-essential offices.

We have carried out similar analysis of the daily case data for Scotland, as published by Public Health Scotland, split by the 32 Council Areas. While there is no Scottish equivalent of the PHE watch list used in England, we nonetheless highlight areas with local interventions, as well as those which appear to us as emerging areas of concern.

We can see that:

  • It is clear why the five Glasgow based regions saw localised restrictions introduced, particularly for Glasgow City. While initially (from 3 September) the areas covered were Glasgow City, East Renfrewshire, and West Dunbartonshire, this was subsequently extended to East Dunbartonshire and Renfrewshire. Over 1m people are now in the affected areas (around 20% of the Scottish population).
  • South Lanarksire, again near Glasgow, has also seen a large increase in cases, so may be at risk of requiring further intervention in the near future.
  • Given the increase in cases seen in both Highland and City of Edinburgh, it is likely that local authorities will be looking closely to see if they can identify any localised outbreaks.

The recently released contract tracing app for Scotland will hopefully help augment the Test and Protect system to help identify any local outbreaks and control their spread.

Case numbers in Wales

Until very recently there had been no local “lockdowns” in Wales. However, residents of Caerphilly are now subject to significant additional restrictions. Whilst businesses can remain open, households can only meet up outside, and the area is in “lockdown” in that travel in and out of the Caerphilly County Borough Council area is not permitted without a “reasonable excuse”.

We have carried out similar analysis of the daily case data for Wales, as published by Public Health Wales, split by the 22 Local Authorities. While there is no Welsh equivalent of the PHE watch list used in England, we nonetheless highlight in the chart below areas with local lockdowns/interventions, as well as those areas where new case numbers/growth in new cases is of concern.

Wales has so far only enacted one local lockdown, in Caerphilly, although case numbers have again been creeping up more recently. In particular, we can see why:

  • Caerphilly was the first Welsh area to go into local lockdown, given the high case numbers and rate of growth.
  • A further 4 areas, shown in red, are causing concern, particularly Merthyr Tydfil and Rhondda Cynon Taf which neighbour Caerphilly; Powys, although marginally below our new case rate trigger, is similarly positioned on the chart to Wrexham and Neath Port Talbot; and so all three may also cause concern in the near future.

Around a quarter of the Welsh population is covered by areas which have concerning case numbers and/or rates of growth.

Case numbers in Northern Ireland

Thus far, Northern Ireland has not introduced localised lockdowns or interventions, relying instead on national interventions. However, of the home nations it has the highest level of new cases per 100,000 for the last week and so increased intervention seems likely. Indeed our news feeds were suggesting local restrictions were being introduced in the Belfast area, Ballymena, and some specific postcode areas as we were finalising this blog. 

Our analysis of the daily case data for Northern Ireland, as published by the Department of Health, split by the 11 Local Government District is shown below. While again there is no equivalent of the PHE watch list used in England, we nonetheless highlight areas of concern. 

We can see that:

  • Belfast is most at risk of requiring further intervention in the near future, given the relatively high cases and growth seen recently – and local interventions appear to be being announced as we publish this blog.
  • Lisburn and Castlereagh is also likely to be causing concern to the local authorities, while Mid and East Antrim will also need to be carefully monitored.

Direction of travel

The direction of travel for new cases is concerning. It appears likely that more authorities in England will be added to the PHE concern list on Friday than are taken off, while a number of additional areas across the UK are giving us cause for concern. We will continue to monitor our “case watch” over forthcoming weeks.

One concern we will be looking closely at is the “migration” of the points in our charts. There seems to be some momentum behind local authorities moving to the right (growing case numbers) and upwards (high daily new cases). This has already led to ‘clusters’ of local lockdowns in the Glasgow area.  If these clusters were to continue to expand, and further clusters appear in different regions, then the likelihood of requiring more widespread national action will only increase. We hope that careful monitoring, combined with localised public health interventions as and when required, will help contain the spread of COVID-19, particularly as we move into the more dangerous winter months….



Notes:

1. For those familiar with the English local authority system these are “lower tier” local authorities – the smallest regional unit where data is readily (and publicly) available.

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