Thursday, 4 June 2020

Hardship and Uncertainty - how long will we be living with the virus?

THE UNEXPECTED KILLER

Few people in the UK seriously envisaged a worldwide pandemic such as the one we have now. I recently spoke to a former member of the Wales Pandemic Committee who described the meetings as often more of "free lunch" than a serious attempt to work through the reality of various pandemic issues. Apart from setting aside stocks of masks and gloves, very little was done.

It's said that in the West we were expecting the next pandemic to be another strain of influenza. The plans were based on epidemic precautions to treat diseases like swine 'flu.


NHS " managed" first wave of SARS 2 ,but many patients still waiting for routine treatments


In 2009 -2010 a pandemic flu epidemic arose in Mexico and spread across the world. At least a quarter of a million people died, but because many European elderly people had some useful immunity to this type of 'flu, it did not have the devastating effect that was expected. Since then, flu vaccines have been used extensively in the West to shield the vulnerable from influenza outbreaks with general success.

In the Middle East and Far East,they had  experience with the new pandemic diseases SARS 1 and MERS, which  probably gave their countries, who had experienced nasty coronaviruses before, an advantage when Covid 19 emerged as it was similar to these previous diseases of which they had experience earlier in this century. They already had the expertise with deadly coronoviruses to use immediately. It is so close in nature to SARS that Covid 19  is officially now referred to as SARS - CoV2, - SARS2 for short

SARS 1 - Severe Acute Respiratory Syndrome was a very similar coronovirus, originating in bats and probably mutating after close exposure to other animals, which emerged in  China in 2002 and caused 8.000 cases over 26 counties with almost 800 deaths.. Like Covid 19 it is thought to have come from live food markets where animals are kept in close proximity to each other and in poor conditions. The symptoms were very similar except that diarrhoea as well as a high temperature and cough, was a common symptom. It was a severe illness and death rates were higher with around one in 3 cases needing hospital care and one in 10 people dying. This compares to a 1% death rate of SARS 2/ Covid 19 , the virus active here now.

Empty Streets across Europe - now lock downs being relaxed  
BORIS' INVISIBLE MUGGER

In the original SARS outbreak no drug cure was found and despite years of work, no vaccine  was ever produced. The disease was controlled and eventually eliminated by screening for high temperature, isolating those with symptoms and their contacts, and strict infection control in hospitals. As it was a more severe infection ,it was easier to track down carriers and follow up contacts.

 With SARS2 /Covid 19 many people have the virus and spread the virus with no symptoms themselves. A recent research report from China suggests that these carriers may feel well but still have the distinctive lung lesions of SARS "on CT scans, adopted by many Chinese hospitals for instant diagnosis, rather than a swab test with a wait for a result.
JAMA. 2020;323(14):1406-1407. doi:10.1001/jama.2020.2565

The Chinese have used lung CT lung scans for diagnosis and evaluation from early in their epidemic as they usually show the very distinctive Covid 19 lung lesions, even in those who feel well. In the UK we have struggled with testing for various reasons, and were not able to quickly isolate cases as the Chinese were, nor probably did we have their access to CT scanners.

We were in the UK  prepared for 'Flu, we had pandemic committees across the UK, officially "ready"  for a deadly flu epidemic but with no apparent expectation of a SARS type virus. Along with the large number of asymptomatic carriers, and the ease of spread,, the UK was unprepared for this new illness.

RESPONDING TO A NEW ILLNESS

The UK Government was reasonably quick to try to preserve the economy, setting up various schemes to lay off workers on 80% pay, a plethora of grants and financial assistance and a blatant  abandonment of most self employed people with modest incomes.

Here in Wales converting Rugby Stadiums and other buildings into hospitals that we eventually did not need, became a bit of an obsession .Now they are being reviewed. we will probably retain a few but the ones which were completely unused may well be "stood down". People who recover from ITU treatment do often need rehabilitation but it seems that the survivors were fewer than calculated and extremely keen to get out of hospital and have physiotherapy in the community.

Its difficult to assess whether or not we are  about to get a significantly bigger second wave , but in the absence of a vaccine or a preventative drug it would be logical to assume that we may well get a second wave and until we get on top of this virus, could easily have more waves later on.

SARS 1 was eliminated by 2004. It was starved of life by stopping people spreading it to others. Some of the survivors were monitored for antibodies long term, they all had plenty to start  with and the antibody counts fell off over 3 years or so, but not entirely, There were a big efforts to make a vaccine to SARS1 but none were successful, and as no new outbreaks happened the projects were abandoned.

WE NOW KNOW MORE, BUT IS IT ENOUGH?

SARS2 is a different animal in that a lot of victims do not show symptoms immediately, and some not at all. These cases are all infectious. Out doors is relatively safe because the virus appears mainly spread by coughs  and breathing, and outside the air dilutes it quicker. It takes a number of virus particles to start an infection and overwhelm our defences, so concentrating many people close together helps the virus spread easily,  hence social distancing .

 Indoors is more dangerous as the viruses can accumulate in the air and get breathed in more easily. Hygiene, hand-washing,social distancing and face coverings should help slow the spread, but relatively few of us have met this new virus before and so most of us probably have no immunity to it. We won't know until antibody tests are readily available to the public, how many of us have already had the illness.

 Research seems to be showing that the amount of virus carried by patients in their nose and throat is much the same in those who feel well throughout their infection compared to those who  are sick. So even if all of us who have symptoms isolate for 14 days , many people will still be distributing the virus into the air and on urfaces without even realising the danger they are to others. Some of these will eventually feel ill but many others may never know they have had it, without the further  tests not yet available to the public.Test , track and isolate is not as easy with this particular bug.

It seems easy - test everyone who feels ill with the right symptoms, if they are positive isolate them, find out who they have been in contact  with, and tell them to isolate too. If they get symptoms, they get a test as well and their contacts are traced if that test is positive. The idea  is to chase down every new infection and catch anybody likely to be a carrier before they have a chance to infect anyone else. In the end the virus is starved of victims and dies out.

There are a few things which could be problematic and make this difficult:

The accuracy of the testing.

No test is absolutely 100% effective. The original tests used in the UK had a significant false negative result, some because the virus was at too low a level early in the infection and others due to poor swabbing technique and problems with the test itself, but in combination some calculated that 10% or more positive cases may have wrongly been given negative results.
Presumably we have more accurate testing now, as if not, we will lose some cases which should  be isolated and have contacts traced. False negative tests could leave infectious cases in the community with false reassurance.

The number of cases infected who have symptoms.

There is now lots of evidence that this disease has a considerable number of asymptomatic carriers. These people feel fine and may never be aware that they are carriers. Some of these are the legendary "super spreaders" and these people unknowingly are dangerously infectious. Also, as the protocol is only  to test those with symptoms, these cases could be totally missed,

Co-operation of the public

There must be public trust for co-operation. People must understand why they must self isolate and at present  the plan is to ask everyone to self isolate after contact, even if you have had the virus before,

To self isolate for 14 days takes some commitment if you think you have already caught the virus, been isolated or even hospitalised, and got over it. I think these people will naturally feel most aggrieved , and should be offered an antibody test which  is evidence for having had the virus and recovered with some immunity

Although it is true that we do not know exactly how long the immunity lasts, it probably lasts at least a year and maybe longer if the SARS1 data is relevant. As we actually have do have antibody test kits to check the presence of antibodies, surely we could use them?

There have not been any proven cases of reinfection after recovery from the illness but there are cases of long lasting disease with complications where the virus was secreted for a long time before the patient was finally clear of the virus, This allowed them to test positive some weeks apart but was not thought to be a new infection, just a resurgence of the original one.

There is no scientific evidence I can find of any people definitely catching it twice. As there is no drug treatment for the disease, every survivor has had antibodies to the virus as it was the only way they could have recovered is through their own immune system finally killing the virus.

The Asymptomatic Carrier Problem

The test. track and isolate policy is planned to be used with symptomatic people. already sick with the virus. We know that many people just do not have symptoms, so may not be picked up.

 For instance an asymptomatic carrier may pass the virus to 2 people. He or she recovers without even knowing they were were ever infected. Of the 2 people infected by them,  one becomes sick, lets call them A, has a test and A's contacts are tracked and isolated and A isolates too.The original case may now be testing negative and may be asked to isolate,as a contact of A but its too late. Theyare  probably not infectious now. Even if they did test positive there is no way of knowing whether they were  infected by A, rather than the source of A's infection.

 The other has a mild or asymptomatic case, lets call them B and never gets tested and is unaware they are infectious,. A and B may not ever have met,  B may go on to infect other people. So this test ,track and isolate strategy in the presence of asymptomatic carriers may take a long time to totally eliminate the disease. It will "miss" some cases which are infectious but not exposed as such.

So  the hint of terror on the faces of our politicians and their medical and scientific advisers at their daily briefings is not just chronic stage fright, they are really worried..

We are dealing with a virus for which we  currently have no cure, and no prevention yet, other than stopping people getting close enough to each other to catch it or pass it on. Its not easy to spot who has it, hence the temperature checks at airports etc. Even these are not totally reliable.

 A study of 78 people who tested positive in Wuhan after visiting the wet market, where the original  outbreak occurred, 42% were asymptomatic. They were predominately female, and younger than the others in the group.

.Other studies suggest that asymptomatic carriers are present in between 25% to 50% of  all people actually infected. I doubt the scientists are confident of quickly containing the virus if up to half of all who get infected are not even aware of their condition. Add to this that around 40% of people  who will become ill  probably pass on the virus before actually becoming ill.  Eliminating the virus may not be easy. For the time being we are going to have to live with it, by hiding from it , while we cannot be exactly sure about who may actually have it.  Hence, avoiding everyone, as we cannot tell who is a carrier?

JAMA Netw Open. 2020;3(5):e2010182. doi:10.1001/jamanetworkopen.2020.10182

 Perfectly well looking people who don't realise they have the virus are as likely , or even more likely, to spread it as those who feel sick having similarly contracted the same virus. It is easy to catch from other people and Winter is coming, the time when we usually seek out warm and sheltered places in which to live, work and socialise.

The decisions of what to do are not easy. Since the first cases, we know more about the virus, but not enough to quickly eliminate it. Our doctors and medical staff are becoming more skilled at keeping severely ill people alive. Less people are dying  but too many are still  being killed by the virus.

For our leaders the difficulty is to balance the health issues with the massive hit to the economy we have taken. Enough people have already lost their jobs or had their businesses devastated.Tens of thousands of people have died in the UK and hundreds still die every week.

LIVES VERSUS LIVELIHOODS

 The more we restrict social contact the closer we get to eliminating the virus, and saving lives. Test, trace and isolate is not as straightforward as it looks in theory. Its going to take time and we probably will be fire fighting outbreaks until we get good immunity Either from a vaccine or from lots of us catching it, herd immunity will eventually reduce or stop the infection enough to return to "normal life", Neither path is likely to be quick or easy.

However, the more we restrict social contact the more we restrict important areas of the economy, the more jobs we lose, the more debt we incur. The poorer the Country gets.

Will the banks and big businesses dictate  policy yet again?  


How much weight and effort the Governments of Britain put into saving lives and saving the economy are largely political decisions; according to their powers ,ambitions and what they believe their populations will accept. However, the crisis itself  restricts their choices considerably, as so little is predictable, and much unknown. The available options are very limited and none of the strategies are without the danger of failure. It is not a simple choice between degrees of lock down and economic growth. The virus was completely novel and in many respects so is the strategy for manging the situation.

Who will decide the priorities? Probably not us!

 Siân Caiach 

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