The Isle of Man has had no newly confirmed cases of Covid-19 for nine consecutive days. The total of confirmed covid-19 positive cases in the Isle of Man remains at 336. Of those 309 (92%) are presumed recovered, 24 (7%) have died and 3 (1%) are isolating in the community.
The positives continue:
- Out of the 512 tests concluded over the last nine days, every single one was returned as negative.
- The number of presumed active cases stands at 3 cases. This is the lowest level of confirmed infection in the Island since 21 March 2020.
- There are no patients being treated at the hospital as a result of Covid-19.
- There have been no covid-19 related deaths reported for 14 days.
- 92% of confirmed cases are recovered, sadly 7% have died but a very low 1% are active.
Keep safe all of you.
The graph below shows the development of confirmed covid-19 cases in the Isle of Man. This graph is derived from the daily statistics published by the Isle of Man Government.
The figures detailed below where the header or the number is in blue shows the daily statistics published by the Isle of Man Government. Those depicted in red are derived directly from the blue figures. For example if we know how many concluded tests there are and we know how many of them resulted in a positive result then it follows that the balance are those that have tested negative.
The figures highlighted in yellow are confirmed by the Health Minister as being inaccurate.
Modelling by the Isle of Man Government
The graph below is that which is published on the government website. On 24 April 2020 Mr Ian Wright provided an explanation of the modelling methodology employed in deriving the graph below.
This is reproduced here:
The first thing to say is that a model is simply a tool to help preparations – it’s not designed to make exact predictions as to exactly how many patients might be admitted on any particular day, or exactly when the peak of infections will arrive.
The basics of the model is that it is a mathematical function that gives a figure for how many new cases of covid may appear on a given day. It’s based on exponential growth, which is when the cumulative number of cases one day is a fixed multiple of the number of cases the previous day. We’re probably all familiar with the R value, which in epidemiology is the basic reproduction number. It is a figure that indicates how many people each infected person will give the virus to. The exact number is unknown, and depends on not just the virus itself, but on how people behave; A reasonable estimate for illustrative purposes for coronavirus would be R=3. Another important number is the time a person is infectious for, which for covid is about 5 days on average. So, if we have 1 case of covid, in 5 days time there will be another 3. Those three will infect 3 each over the next 5 days and so on. In that way we have a sequence of 1,3,9,27,81,243,729… new cases appearing every 5 days. It doesn’t take long until the infection is widespread.
A similar function was entered into an Excel spreadsheet, with a slight modification to take into account that cases can’t keep growing for ever as you eventually run out of people to infect, and this was used to generate the curves we’re all familiar with. The curves are presented as a set of 3, with a different daily growth rate. The blue curve, with the highest soonest peak, is a daily growth rate of 20%. In the first version of the model we used 29% as this was the figure calculated from the early phases of the epidemics in Italy and Spain, and I thought this probably represented the worst case scenario. It was changed to 20% because this is the growth we actually saw on the island before the effects of the lockdown 4 weeks ago came into being. So the blue curve represents what may have happened here if the government hadn’t brought in the restrictions in the latter half of March.
The middle red curve represents a growth rate of 12%. You can see that the effect of reducing the growth rate, which is what happens when you reduce R by introducing all the ‘stay-at-home’ measures, is to flatten the curve and push its peak to the right. In practice this buys you time to prepare the health service by freeing up capacity, re-purposing wards as intensive care units, training staff to run them, and reduces the level of peak demand so that your enhanced health service can cope, rather than ending up in a warzone situation, dreadful scenes of which we probably all saw from Northern Italy a month or so ago. The figure of 12% was what was seen in Germany, and what we thought would be achievable here, and so the red curve was used to guide planning at Nobles in terms of extra intensive care beds, dedicated Covid ward beds, PPE requirements, Oxygen need…
The orange curve represented what we thought was aspirational, or a best case scenario. It was generated with an 8% daily growth, which was a figure I calculated we might achieve if our lockdown measures were successful in halving the R value.
Since the lockdown measures took effect, on about the 3rd April looking at the log-plot of the actual case numbers here, our growth rate in cases has actually been lower than this so-called best case scenario. It’s averaged only 5.5%, and that includes the outbreak in Abbotswood which has accounted for the majority of the cases over the last 10 days or so. Without these, we’ve had only a few cases each day and none for the last 2 days, suggesting the spread in the wider community has all but stopped.
Health is perhaps the most obvious aspect of an epidemic to consider, but there are also major considerations with regard to society, psychological health and of course the economy. The sooner we can get back to a more normal way of life the better it will be for all of these aspects. It’s only sensible that plans to loosen the lockdown are gradual and monitored. Health is of course vital, and we must be confident that should any of the measures cause an increase in cases of covid that we’ll be able to cope with them. We’re currently well below the 12% growth used in the planning assumption, and calculations based on the small increase in R that may happen by letting the first sectors of the economy return to work indicate there should be a minimal effect on the current growth which will remain below this figure. In fact I’m fairly confident it will remain below the 8% ‘best case’ scenario. But this will of course be monitored very closely, specifically looking at what happens in 8-10 days time.
The modelling has, in many respects, done its job. We now need to focus more on monitoring the real situation here, not just with positive cases but also calls to 111, ED attendances and bed occupancy. Testing, and I’d like to pay tribute to Rizwan Khan and his team for such a sterling effort in getting the island testing to the stage we have it today, remains vital if we’re to keep the virus under control on island while slowly getting back to some semblance of normal living. In the meantime of course it remains vital that we keep up the social distancing, hygiene and self-isolation if required.
The following charts were shared by Minister Ashford at the daily briefing on 18 April 2020 and have not been updated with the more recent statistics.
The first chart shows the age spread of individuals who have tested positive for coronavirus in the Isle of Man across age groups.
This shows that the spread of the virus is across the full spectrum of ages.
It is interesting to note that the age bands under 65s have the most positive test results, although the profile may change as we move forward.
This isn’t a virus that just attacks the older members of society and shows why we all must heed Government advice and guidance.
And that is, to stay indoors, save lives, and protect our health service.
Covid-19 by gender
The next chart breaks down confirmed positive cases of COVID-19 by gender. A fairly even split but slightly more female at approximately 56% shown in the chart as 163 cases.
Covid-19 cases confirmed with health workers
The following chart specifically shows how this virus has affected our health workers. At the date these figures were reported we have had 47 positive cases amongst our healthcare workers, 30 are active, 4 hospitalised and 13 that have been discharged or presumed recovered.
Transmission of Covid-19 in the Isle of Man
The final chart shows how the virus has been spread. The largest section as you can see is by close contact at 40% which again highlights the importance of social distancing.
This virus is indiscriminate of age or gender. Being a particular type of person will not protect you from contracting this virus.