90 Sloane Street: The Coronavirus Covid 19.
Bulletin 2 - 23rd March.
Differences of Covid -19 from normal flu
With Flu you know you are ill straight away, whereas with Covid19 (with its long incubation period of 3-14 days) people can be developing the infection and infecting other people before they are aware of any symptoms.
Covid 19 spreads more than SARS or MERS as there are a large number of people with mild symptoms who are continuing their normal activities, driving on the transmission chain of the virus.
The mortality of normal flu is about 0.1% - 1 in 1000 people. The mortality of Covid 19 is stated at present at about 3.5-4%. However, many people have had the virus but have experienced little or no symptoms and these individuals have not been included in the figures. If they had been then the mortality rate would be much less.
Covid 19 spread
Unlike some respiratory infections, Covid 19 is spread is by droplets which are of a larger size than those from an aerosol (as opposed to some respiratory infections). With an aerosol it is a bit like spraying air freshener – it goes over all the room and hangs around, but droplets will fall rapidly onto hard surfaces. You contract Covid 19 either through inhalation of droplets or through droplets you have touched and then transferred to your mouth, nose, or eyes.
• Do not touch your face.
• Repeatedly wash your hands.
Can you be re-infected if you have already had the infection?
We do not know the answer to this as yet. Generally when you are infected by a particular virus, you develop antibodies against it and will be immune to that virus unless very rarely the virus changes significantly.
How long can the virus live on a hard surface?
On tables and stainless steel, for example, it will live for a few hours to 24 hours. However it is very sensitive to alcohol or dilute bleach, so do wipe surfaces. The dilute bleach should be done at a 1 of bleach to 10 of water concentration. The alcohol concentration should be above 60-70%. If you have a solution of 90%, then you can dilute it to extend it. Note, Scotch won’t work – it is too low in alcohol!
What can you do to reduce your risk?
Social isolation and distancing and washing your hands.
Do continue to walk and exercise but keep a decent distance away from people. We would suggest an exaggerated space of four metres not just two. There might be a sudden puff of wind. Keep on walking, hiking, jogging and biking.
High-touch areas – be aware of light switches, door handles and bells, desks, as well as kitchen areas. Try not to use bare hands to touch switches etc.
Boosting your immune system
1. Adequate sleep.
2. Good nutrition.
3. Good multivitamin.
4. Drink lots of water.
5. Vitamin D 2,000-4,000iu per day (unless you have kidney stones).
6. Zinc may be helpful in infections. Do not take above recommended dose as this can deleteriously affect your copper levels.
What about routine hospital appointments?
If you have routine eye checks, skin checks, or dental checks, these should all be postponed until after this pandemic has subsided.
Will the spring help us?
We do not know about the infectivity of Covid 19 in warmer weather, and if there will be a summer respite. There are concerns that it is continuing in hotter climates.
If significant lung inflammation develops the main treatment for Covid19 is maintaining an adequate oxygen level. The first step is giving oxygen via a mask or nasal prongs. If there is any wheezing, a salbutamol nebuliser to open the airways will be prescribed. In 15% of patients there are superadded bacterial infections where the antibiotic azithromycin is often given. This has some antiviral effect.
If the oxygen levels remain low despite supplementary oxygen being administered, it may be necessary to ventilate the lungs mechanically. This way higher levels of inspired oxygen are achieved, and the lungs can be expanded with positive pressure (PEEP). Interestingly, a good aspect of Covid19 infection is that the lungs do not become stiff, therefore they are quite easy to ventilate, not needing high inflation pressures which increase risk of complications.
In some circumstances, if despite ventilation, oxygenation is still inadequate, patients are put on the equivalent of a coronary bypass machine so-called ECMO (extracorporeal membrane oxygenation). There are only a limited number of hospitals which provide this facility including the Royal Brompton, St Thomas’s, and St Bartholomew’s.
Hydroxychloroquine and azithromycin
We are going into some detail here – as we feel it is a really interesting option and we do have some inside information.
Hydroxychloroquine: for some years there has been interest in the effect of hydroxychloroquine on coronaviruses. It is an antimalarial as well as being an immunosuppressive drug, which has been around since the 1940s. It is used also in certain types of arthritis.
Mechanism of Action: it increases lysosomes activity, increasing the pH of the cell so that the virus cannot attach itself, as it needs an acidic environment. It is therefore harder for the virus to get into the cell.
Coronaviruses attach themselves to ACE2 receptors in the lungs. Hydroxychloroquine makes it more difficult for the corona virus to attach itself to the ACE receptors. Children are less likely to have Coronavirus infection as they have less ACE receptors meaning their symptoms are milder.
Hydroxychloroquine is an antimalarial which has been available since the 1940s. Sometimes it is also used in certain types of arthritis.
Hydroxychloroquine increases the pH of cells so that the virus cannot attach itself, as it needs an acidic environment. Usually it attaches to ACE2 receptors in the lung. Hydroxychloroquine inhibits this. Children have less ACE receptors, and so they have less risk of infection and complications from Covid -19.
A recent trial of Hydroxychloroquine and azithromycin involved 36 patients with covid-19 infections. Patients given hydroxychloroquine and azithromycin (an antibiotic that can have some antiviral activity) reduced the time to clear the virus to five or six days, compared to 21 days. In this tiny trial patients were found to improve more rapidly with the combination of hydroxychloroquine and azithromycin.
There is a lack of adequate trial numbers at present, to give strong statistical validation of effectiveness and the hazards. Normally trials are done with thousands of patients to check that a treatment is both effective and safe. Currently some hospitals are using hydroxychloroquine with azithromycin, and others are just doing supportive ventilation and treating bacterial infections if they occur.
However significant trials are now being done in France and the USA of hydroxychloroquine and azithromycin so we would hope to have some clear answers in 4 weeks or so.
Side-effects of hydroxychloroquine are not usually too troublesome but can include diarrhoea, dizziness, itchy skin, headaches, and rarely psychotic reactions with hearing voices. Occasionally low blood sugars (hypoglycaemia) can occur.
It can be toxic to the retina of the eye, but this normally only occurs with prolonged use. A baseline eye assessment is usually done when starting patients on hydroxychloroquine. An electrocardiogram (ECG) is also carried out to look at the QT interval. Both hydroxychloroquine and azithromycin can cause ventricular tachycardias - a rare but serious cardiac rhythm disorder due to their prolongation of the QT interval.
Recent Unsuccessful Drug
Remdesivir: a nucleoside inhibitor used for Ebola and SARS: The trial evidence is not impressive for covid 19.
A new trial of a protease inhibitor for HIV patients to reduce viral load, showed that it did not help as published in the New England Journal of Medicine.
Testing for Covid 19
This is a rapidly changing field. There are now two main systems available:
1. A polymerase chain reaction (PCR) test for the virus.
As of this Thursday or Friday 26th or 27th March, we should have kits arriving which we can give or send out to patients so that they can do their own testing for the virus, via swab. They then send it off to the lab and from the time it arrives there will be a result within 3-5 days. The cost of this will be £320, as we have had to pay extra for these kits. In about 12 days when we can have our own direct supply of kits, the cost will be reduced to £285.
This swab test will tell if you have covid-19 and also check for several other viruses. It will be positive once you have had viral symptoms for 2 days.
The lab involved is working with Public Health England and we have good trust in it. It is a high-quality test, and the chance of the test giving a false-positive is only about 2%.
2. An antibody test detecting antibodies you produce in your blood, in response to covid-19.
Please see Bulletin 1 for further details on this type of testing.
We do not know yet how long it takes to produce the IgM antibody from the onset of symptoms so therefore do not know quite how useful it is in early covid 19 detection. It is likely that the first PCR type of test as described above will be the test that can make the diagnosis at the earliest part of the illness.
IgG is the memory antibody and will stay positive if you have ever had covid-19. This will be so useful, as people who know they’ve had it can get on with their lives. Additionally, you should be safe around patients suffering from the virus. We expect to have these test in 10 to 14 days.
We are acting in the public interest as all test results will be given to P.H.E.