COVID-19: Case-Watch as at 15th October

As a response to growing case numbers in England, the Government introduced a new 3-tier alert system this week to try to supress the spread of COVID-19 at the local level without having to resort to another full national lockdown. Each area in England is classified as “Medium”, “High” or “Very High” alert, depending on the cases in that local area. Currently, only Liverpool is in the “Very High” level, although Lancashire will be moving to this level from Saturday. The Government has also announced that Manchester, currently in the “High” level, will move to “Very High”, but there has been no confirmation of this yet, amidst resistance from, amongst others, the local mayor, Andy Burnham. A large number of regions, including the likes of London and Essex, will move to the “High” level from midnight tonight (Friday 16th October). In this blog we consider whether there are other areas in England which might soon climb to the “High” or “Very High” alert levels.

Looking elsewhere in the home nations, last week we discussed how Scotland implemented temporary restrictions on hospitality across the country, with tighter restrictions across the more populous central belt. We will consider whether there are any early signs that these additional restrictions are helping to slow the spread of COVID-19, and if there is evidence that the restrictions should be expanded to other areas through a mini ‘circuit-breaker’ similar to that implemented in Northern Ireland.

In other news, a computer glitch made the headlines again this week as it was reported that some students’ positive test results were attributed to their home addresses, rather than their student accommodation. It was noted that students testing positive elsewhere in the country were potentially skewing the numbers back home, particularly in some affluent London boroughs. This potential distortion in the data adds confusion to Public Health directors trying to understand local numbers and determine whether an area has “tipped” over the ‘100 new weekly cases per 100,000’ threshold, which may trigger escalation to the “High” risk category. While such issues are likely to cause unhelpful confusion, they should be seen in the context of a rapid rise in cases across most areas of the country.

The overall picture on case numbers

The chart below shows the latest case numbers published by the UK government (as of the afternoon of 15th October). The bars show the daily numbers of new COVID-19 cases across the UK, whilst the line shows the running seven-day average, smoothing through dips in new case numbers which tend to happen at weekends and bank holidays, for example.

The limited testing capacity in March and April means it is very likely that true case numbers at that time were much higher than shown in the chart. We are now able to perform around 10-15 times more tests dailythan at the start of the pandemic. The implementation of “Test and Trace” also means that we are testing more asymptomatic individuals now, and positive test results will now include individuals with only virus residues i.e. who have not been infectious for many days and potentially weeks. As such, the case numbers over recent months (on the right of the chart) are not directly comparable with those from earlier in the pandemic (the left of the chart). The level of adjustment needed for comparability is not at this stage clear, however, the dramatic rise in recent weeks, is of concern and it would seem likely to us that we are in a comparable position now (in terms of new cases) as where we were in mid to late March, albeit with a different age profile of cases. The worry as alluded to in our blog earlier this week is that cases, and deaths, are now rising in the older more vulnerable groups.

Looking at the most recent case numbers, we can see how the rolling seven-day average has continued to increase since last week. The sharp drop in most recent dates primarily due to the time-lag in obtaining testing results, as the figures are based on the specimen date. We would consequently expect the figures for the past few days to materially increase and therefore the analysis below ignores the data for the most recent days, and ‘steps back’ by 4 days. This is designed to strike a balance between showing as up to date pictures as possible, and as accurate a picture as possible, but we suspect some under-reporting remains in the most recent week used for these charts.   

Where the peak of “second wave” in last week’s blog was on the 2nd October at 13,125 cases the peak in the above chart is the 7th October with 18,226 cases. This shows that cases continue to rise fast at the UK level, and restrictions which are in place may not be curbing community transmission as well as we would hope.

It is also worrying that hospitalisations continue to rise. Whilst daily new admissions are not yet at the level seen earlier in the year, the total number of patients in hospital with COVID-19 is now materially greater than the total as at 23rd March when the UK went into National lockdown (3,097 vs 4,379 patients currently). Although it can take time to see the impact of restrictions, both cases and hospitalisations highlight a trend which does not appear to be slowing and suggests that greater restrictions may be required – whether at a local or national level.

Our “case-watch” for England

The graphic below compares this week’s “case-watch” to the previous week – with each point representing a (lower-tier) local authority2 in England. The best case scenario would be for points to appear in the bottom left, indicating falling case numbers and suppression of the virus. If points appear to the right of the vertical line case numbers are rising – what we don’t want to see is points primarily to the right, and especially not heading towards the top right (high case numbers and rapidly growing) as this suggests the potential need to move away from localised restrictions to nationwide restrictions in order to “put the brakes on.” 

The key change between the two weeks appears to be that local authorities are more consolidated and less spread out in the upper-right quadrant than they were last week.  It is also worth noting that as the overall level of new cases grows, so the position on the y-axis is relative to that revised higher level – so a relatively “static” picture like this means systemic growth in new cases across the country instead of singular local outbreaks i.e. new virus transmissions is becoming much more of a national issue.

Focus on this week: The new 3-tier system

In previous weeks we have focussed on the Public Health England watchlist, which indicated which areas they had concerns with, and where additional support or interventions were in place. However, from this week a new tiered system for local restrictions has been introduced. Each level of England’s 3-tier alert system, and the relevant restrictions of each, are set out in detail on the government website, but in summary:

  • Medium: This is the baseline for restrictions, which were in place at the national level. This includes measures such as the ‘rule of 6’ and some hospitality restrictions after 10pm. We mark these areas by the green dots in our chart below.
  • High: This is for areas with higher weekly new case rates. It has been widely reported (but not officially confirmed) that the threshold for escalation from Medium to High alert level is over 100 new cases per 100,000 people. The greater restrictions include no household mixing in any indoor setting (light blue dots)
  • Very High: Highlighted as having a very high prevalence of COVID-19 requiring additional restrictions. Our understanding is that the exact restrictions imposed on any authorities in this category will be selected from a wide reaching menu (and subject to local negotiations around support packages), but local authorities are likely to see, as a minimum, tighter restrictions on the hospitality sector, such as closing of pubs/bars, and bans on household mixing extended further to include outdoor areas. These are marked in lilac on our chart.

The list of areas in each region is published on the government website, and, as at 2pm on 15th October, the in-force list currently names 64 local authorities in the High category (covering ~28% of England’s population) with the 6 local authorities that make up the Liverpool area being the only region classified as Very High – the remaining local authorities are currently in the Medium classification. At the time of writing it has been confirmed that further areas will be added to the High risk category tomorrow, while Lancashire is moving to Very High risk. We comment further on these imminent movements below.

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

Much of the debate around the new 3-tier system has been the decision to only include the Liverpool area in the Very High category. At this stage, it is clear from the chart that Liverpool city centre and the surrounding areas (such as Knowsley) are exhibiting a high increase in cases, both compared to last week and vs the national average (which is also high). Lancashire, including areas such as Burnley, will be added to the “Very High” risk level from Saturday. However the restrictions that will come into force differ slightly from those for Liverpool – for example gyms and leisure centres will remain open.

The government has also expressed an intent to increase Manchester from High to Very High in the coming days. Last week, we highlighted that Manchester was of particular concern and from the chart it does appear that Manchester is experiencing one of the highest weekly new case rates. comparable to Burnley and Newcastle upon Tyne. However, unlike those regions, the number of new cases has fallen compared to the previous week – suggesting that current restrictions may be starting to slow the virus transmission. The extent of this fall though is very dependent on the speed of reporting of test results. We noted earlier concerns that some under-reporting may remain in our charts. Stepping back just one further day suggests the case rate had only very slightly fallen. This highlights the dilemma facing officials in Manchester.

Newcastle upon Tyne has seen high case growth compared to the national level – providing potential reasoning for an increase from High to Very High and the resulting tighter restrictions in the near future.

The “case-watch” chart above also marks several local authorities in red. These are areas currently classified as Medium risk, but which give cause for concern either due to high case numbers, or very high (and statistically significant) growth in the new case rate. Of these, the City of Bristol and Bournemouth, Christchurch and Poole show high increases in cases compared to their position last week. Both also exceed the 100 new cases weekly per 100,000 people threshold (represented by the yellow dotted line) which is believed to be one of the criteria for moving from Medium to High risk levels.

The national weekly new case rate exceeded the escalation to “High” threshold two weeks ago (the horizontal axes being aligned with the case rate for the week to 2nd October) at 111 per 100,000 people.  The weekly new case rate for week ending 9th October was 160 per 100,000, a 44% increase in one week. However, despite this large increase being mirrored across most local authorities (shown by the cluster of points to the right of the vertical axis), a number of areas remain well below the threshold for the time being.

All but two local authorities categorised as High (blue dots) or Very High (lilac dots) have cases greater than 100 per 100,000. The exceptions are Bassetlaw and Mansfield in the Nottinghamshire area and are presumably on High alert due to risk levels in surrounding areas. There are also 66 areas which are currently on Medium alert but sit above the yellow line. These include many of the areas that, it has recently been announced, will be moving into the High category, including some London Boroughs and some Derbyshire Districts. There are though a number of local authorities which appear to be above the 100 per 100,000 threshold, but have yet to hear any announcement of imminent changes to alert levels. It will be interesting to watch developments in the next few weeks to see whether any of the regions of possible concern or above the yellow line are included in the High alert level.

Case numbers in Wales

We have updated our 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 3-tier alert level now 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. Note that as some areas have relatively small populations, the results can be quite volatile from week to week.

In the past week, the only additional local lockdown in Wales has been for the City of Bangor in the Gwynedd region. Although the whole of Gwynedd is not under additional restrictions, it can be seen from the chart that, due to high case numbers compared to last week, it is highlighted as a possible concern. It may be the case that this rise is being driven by Bangor, and therefore the local restrictions just for the city will dampen the outbreak. It will be interesting to see whether this is sufficient and if the cases do spread to the wider Gwynedd region.

Overall, cases are growing in almost every region of Wales, with 20 out of 22 areas (consisting of ~95% of the total population) showing an increase in comparison to last week. As they are grouped closer to the horizontal axis there are no obvious outliers, suggesting that restrictions at a more national level rather than local may be introduced in the coming weeks.

Overall new case rates are similar in Wales to England – running at 153 per 100,000 lives in week to 9th October, up from 106 in the week before. 13 of the 25 local authorities in Wales fall above the 100 per 100,000 people weekly new case level, covering ~66% of the population. However, the response to local vs national restrictions looks likely to favour a national “circuit breaker”, and a ban on entry from parts of the UK with high case rates (areas of England in the High and Very High risk levels, the central belt in Scotland, and all of Northern Ireland) is now in place.

Case numbers in Scotland

Last week the Scottish Government announced a range of restrictions on the hospitality industry. Throughout the country pubs, bars, restaurants, and cafes can only operate indoors from 6am to 6pm, for food and non-alcoholic drinks only whilst alcohol can only be served outdoors until 10pm. Even tighter restrictions were introduced across the more populous central belt, where pubs and restaurants have been closed since Friday 9th October. Cafes can stay open but only if they don’t serve alcohol.

We have updated our analysis of the daily case data for Scotland, as published by Public Health Scotland, split by the 32 Council Areas.

Scotland has the lowest weekly new cases amongst the home nations. For the week up to 2nd October (which determines level of x axis in the chart) there were 82 new cases per 100,000. For the week to 9th October this had jumped to 132 per 100,000, largely driven by rapid case growth in the central belt local authorities.

We can see from the chart that:

  • Cases are rising across most of the country, with only the Highland and Western Isles showing small decreases from the previous week. As they are some of the least populated areas, it leaves around 95% of the Scottish population living in areas where cases are rising.
  • The high cases seen for regions in the central belt, both in terms of previous weeks and the national average illustrate why tighter restrictions have been introduced in these areas.
  • Although not in the central belt, Dundee is showing cases greater than 100 per 100,000 and showing the largest increase in cases vs last week for areas out with the central belt.
  • The growth of cases in Edinburgh was highlighted as particular concern last week, and continues to increase this week, albeit less dramatically.

First Minister Nicola Sturgeon also announced this week that the Scottish Government would look to implement a 3-tier lockdown alert system, similar to that introduced in England, in the coming weeks.  

Case numbers in Northern Ireland

The cases growth for Derry City and Strabane and Belfast areas exceeded the upper limit of the chart used in previous weeks, and for the other home nations above. We have therefore extended the limit of the x-axis slightly to include these areas.

As outlined in last week’s blog, every area in Northern Ireland is showing increased COVID-19 cases compared to the previous week. This trend continuing for the past two weeks highlights the sharp increase in cases, which does not seem to be slowing.

The most populous regions of the country, namely the Derry City and Strabane and Belfast areas, exhibit some of the highest case numbers and rapid growth rates in the UK. Further, the weekly case rates in Northern Ireland are much higher, and growing faster, than those in the other home nations; rising from 164 per 100,000 people in week to 2nd October to 309 per 100,000 in week to 9th October.  This provides insight into the Northern Ireland executive’s decision to implement a national ‘circuit-breaker’ lockdown, with measures ranging from the closure of schools, hospitality, hairdressers and limiting the selling of alcohol from supermarkets.

As Northern Ireland backs out from the localised approach, it will be interesting to see if any of the other home nations follow suit in the midst of rising cases across the countries.


Notes:

1. Pillar 1 and Pillar 2 testing – see our earlier blog which explain the Pillar

2. 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.

Share this article:
Icon/Arrow/UpIcon/Pin/Calander12Icon/Close/blackIcon/Social/FacebookIcon/Social/LinkedinIcon/MinusIcon/PinIcon/ExpandIcon/QuoteIcon/Website-greenIcon/Website/grey