Why is Covid-19 worse than the Flu

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Category: On Corona Virus
Last Updated: Sunday, 25 October 2020 10:42

Covid-19 versus the Flu

The information presented here is subject to change as knowledge about covid-19 is rapidly evolving. Updated October 2020.

  • Covid-19 is a new virus and no one, except those after recovery may have some immunity and even then for how long it may last. There are already known cases of re-infection.
  • There are no drugs or medicines available to cure Covid-19, yet. Our bodies have to do this and keeping fit, healthy, and ones immune system in top condition, is likely the best we can do for ourselves.
  • The rate of infection is measured by the Reproduction Number (R0) which varies between countries, the level of immunity and other factors, and is continually being re-evaluated.
    R0 for various diseases are: Measles 12-18, Ebola 1.5-2.5, Smallpox 5-7, Influenza 0.9-2.1, and Covid-19 1.5-3.5 with its average being 2.5.
  • Covid-19 has an incubation period of 5-10 days. Its not clearly known when an infected person becomes contagious or when it ends, so we have assumed the worst. Latest information has this period, called the Series Interval or Si for short, at about 5-7.5 days. Si is the time between when an infected person detects symptoms and when passed on to another that they detect symptoms.  A high Si slows the speed at which the virus propagates, so when the first person infects another 3 it might be about 6 days before they become aware of it and in the meantime infect others.
  • Influenza has an incubation period of 1-2 days. Most people are home in bed before they become infectious and usually only infect one other, but with a lower Si the spread is quite fast. Many also have some immunity, either naturally or by vaccination. When R0 is less than 1 the virus slowly dies out.
  • The latest tests for Covid-19 are now effective before a person becomes ill, if at all, and getting results of tests is not yet immediate and this is what makes it so difficult to control. Our only defense is to find (contact trace), isolate, and test all contacts of a person who tests positive, hopefully before they also become spreaders. Genetic tracing of the virus strain has helped greatly in establishing those infected from the original source and therefore part of the same cluster or tree and can be eliminated.
    Wearing a mask won't necessarily protect one from catching the virus, as it might have collected on the mask surface and get transferred from there to hands an then back to the face when the mask is removed and disposed of. However, if one is already infected the ability to spread the virus to others is greatly reduced.
  • Covid-19 is more dangerous than influenza which many die form each year, but we do have a flu vaccine. Covid-19 is far more contagious and can survive on surfaces longer thus spreading to more people and being airborne makes transmission easier, but its the higher R0 and our lack of immunity that's the problem.
  • Covid-19 is known to cause deaths in people with existing conditions, as does influenza. Emerging factors are those who are obese, have heart, lung, or immune weakness. Residing in cities with high pollution levels also exacerbates lung issues.
    Some healthy people, when infected, seem to cope for 7 or so days after becoming ill and then suddenly change for the worse needing hospital care. It is thought that children's lungs may not have yet developed the type of cells that get attacked, but if infected they are still contagious. Watch the second video bellow to see how each symptom progresses onto the next.
  • Most recent research is pointing towards it being able to adapt to the weakness of individuals and seems to depend on the symptoms that manifest. For those that get seriously ill its for various reasons. Children, for example, seem to get blood issues and adults don't always get lung issues. Its now known that Covid-19 can attack in various ways other than respiratory, with brain, liver, kidney on the list as well as blood issues. This now makes it much more serious than the flu and latest research published by the CDC places the danger of Covid-19 about 5 times greater.

Math behind spreading infection and Fantastic supporting Videos

  • A person with Influenza is likely to only infect one or maybe two others in total. So its more like pass the parcel, and Covid-19 a chain letter.
  • A single covid-19 infected person is likely to infect 2.5 people for every day until they become ill, if at all. After a few days that person may have passed it on to a further 3 people. And each of those 3 people may have infected another 3 people - and so on. The formula is R0^T where T is time or number of repeats. Some calculators have this as a button like YX.
  • A simple exercise to demonstrate this for children, using an R0 of 3, is with some bowls and a pack of rice or similar - lentils, peanuts, etc. Each grain will represent 1 infected person. Place the bowls in order and label them 2-6 in some way - post-it notes or bits of paper. To represent the time after first infection, place 3 grains in bowl #2, (For the first person plus the two more they infected.) In bowl #3 place double the number of those in #2. Now tip the contents of #2 into #3. (Total No. of those now infected.) In bowl #4 put double the number of those now in bowl #3. Then tip bowl #3 into #4 to represent the number now infected. Repeat this process for bowls #5 and #6 or more.
  • After tipping #5 into #6 it should contain 243 grains. By continuing this process to bowl #10 it would contain 19,683 grains. However, earlier infected people now feel ill and isolate, so earlier grains can be removed from this bowl before proceeding to bowl #11.
  • The example assumes a constant infection spread from day 2 and doesn't apply the Si, but the effect is similar and only delayed. Also it assumes a constant daily rate of infection, whereas in practice it happens less frequently, but in larger numbers where people meet in clusters. e.g. None for 5 days and 30 the next. Including those already infected plus double the next day produces the same as with an R0=3. We show it this way in the example to reduce the total number of grains required. Either way the spread increases exponentially.
  • The death rate has been estimated at between 1 and 3.4% depending on the country. USA at the time of writing is over 5% and for the world 7%. These figures are likely inflated because the total count is of those who tested positive. It is estimated many more infected and untested people exist which reduces the death rate percentage. It also may never be known how many deaths might be Covid-19 related when not tested.
  • In our exercise, after 10 days with a death rate of 3%, 590 people are doomed, and over the next 10 days will all be in hospital. One day later another 1700 odd are predicted to join them and the medical service is now completely overloaded.
  • Being of an RNA type, corona viruses can mutate and possibly become worse if allowed to spread widely. It has been suggested that there are two strains, one more virulent than the other and might be the reason some are not seriously affected.
  • From the above it should be obvious that preventing ongoing transmission is the only option to reduce infections and hospital admissions until we have a vaccine. In countries where infection rates are out of control, flattening the curve by lock down is their only choice, and that in time, by increasing heard immunity naturally or by vaccination, will eventually bring it to an end. This will likely require isolation in some form to continue for many months for medical services to cope.
  • Without full PPE, medical staff themselves become infected making medical support worse or non existent.

Supporting Videos

These are created by qualified people and worth spending the time to watch. This is short animated and recommended for children.
Corona Virus animated video

This a very informative and detailed using correct medical terms, and although 50 minutes long mostly very easy to follow. It considers the source of viruses going back to the SARs epidemic, spreading rates, and Covid-19 progressive effects and bodily symptoms. Zach, the creator of these videos, is a professional lecturer for medical students and many in the profession, have viewed them and in their comments praised him for the clarity of his presentations.
Corona Virus - Epidemiology, Pathopyhsiology and Diagnostics

A 30 minute follow up on the above, covering treatments and prevention. Its likely to create an immediate desire to wash your hands.
Covid-19 - Treatments and Prevention

More updated videos on Convid-19 are now available on his You-Tube channel. 

Conclusion

  • Here in N.Z we are extremely fortunate that most infected returnees from overseas went into isolation, and that a lock-down was activated immediately that non-associated person to person infection was suspected.
  • This gives us a fighting chance that it can be totally eliminated with the hope that we can live normally until a vaccine becomes available. Latest information has the R0 in NZ at about 0.5 and that we could indeed succeed in this with all the pain being worth it.
    NZ has done this before with the Australian fruit fly, and in 1996, the eradication in Auckland of the White Spotted Tussock moth, which was considered impossible at the time as no other country had succeeded. The pain and issues of aerial spraying was again worth it.
  • Newer studies of the Spanish Flu pandemic in 1918, has showed that districts and towns that introduced separation and isolation early had a faster and greater economic recovery. (Person zero was eventually traced to a USA farmer breeding ducks.)
  • So please, stay in your bubbles and don't be the one person to fail at breaking the transmission chain by not wearing a mask where possible.