Since the outbreak of the coronavirus it is amazing the number of people that have become statisticians of the common flu. Because the clinical presentation of coronavirus is similiar to Influenza it is tempting to compare them I suppose. The basic point of these people is that the common flu is also contagious and kills millions of people a year. A lot more than the coronavirus and as such if we don’t worry about the flu we shouldn’t overly worry about the coronavirus. While the basics of this argument hold somewhat true – the argument misses two vital points.
- Transmission rates
- Infection / death rates
Each infected person with influenza, generally speaking, will infect about 1.4 or 1.5 other people. In epidemiology this is called the R0 value. This value informs scientists how transmissible any particular disease is. Unfortunately with COVID-19 that value is much higher. Evidence to date points to an R0 value of between 2.6 and 3.0.
In simple terms the coronavirus has the capability to spread much more rapidly than influenza. There only two ways of dealing with an epidemic of this nature. The first is to produce a vaccine for it, obviously this solution is many months away at the moment. The second is social separation. This is what China has been attempting to enforce for the last 5 weeks. Quarantines and lock-downs. 700 million people have been in some form of self separation for most of February in China. However, the explosion of new countries that have reported the virus in the last few days suggest their efforts have ultimately failed.
New countries victim to the coronavirus will also attempt this type of containment in the early stages. If it is not successful there comes a point when containment strategies become pointless with such a rapidly transmissible disease and some countries will have to move from a containment to a management strategy. I suspect if the Chinese information firewall was dropped this what you would see now. More of a management rather than containment effort. Allowing the disease to dwell amongst the population until a vaccine is found and treating only the most significant symptoms. Harsh but ultimately that is the truth of it.
One of the emerging observations on COVID-19 is that it seems to have an ability to exist on surfaces for a period of time and it is one of the reasons hand hygiene is being hammered home on Public Health websites. This ability to survive obviously feeds into the virus’s ability to transmit at a rate much greater than the flu.
What we can definitively say is that the Death rate for the disease is very highly determined by the quality of care that a patient gets. Allowing for differing health standards around the world scientists currently point to a death/infection rate of between 0.5% and 1.1%. Even at these rates the coronavirus is 5 to 10 times more deadly than the common flu. As more and more data comes in this death rate will become more accurate and perhaps even reduce. Early in the cycle of this pandemic, the death rate in China was consistently hovering at 2.1%. What we are learning as weeks go by is that most of the numbers China has presented to the world are simply not accurate.
As of today Friday February 28th South Korea has reported 2,337 infections with 13 total deaths. This type of Infection/Death Rate is evidence of what great health care facilities, reporting and detection rates can achieve in reducing the numbers of people dying from the disease. Sadly most countries will not have the standard of response that South Korea has been able to produce. Iran is a case in point. It only has 270 confirmed infections yet is reporting 28 deaths. An infection/Death rate of over 10%.
A particular characteristic of the coronavirus is that people become infectious to others very early – it’s thought it might be as quickly as 12 hours from first contact to coughing the virus out or shedding the virus externally in other ways. This is a significant difference between COVID-19 and say SARS. COVID-19 is pre-symptomatic, it transmits well before any signs of symptoms. Scientists are still trying to definitively identify how long people remain infectious, early indicators signaled up to 14 days but there have been numerous examples where patients remain in an infectious state longer perhaps even up to 21 days.
Another complicating factor is that coronavirus can take up to 7 days to present any symptoms at all. The WHO have indicated that the world is in a narrow window where the virus can still be contained globally, but it time is running out. If containment strategies ultimately fail it is estimated that 30% of the worlds population could become infected in Year 1.
February 28th Updates.
50 countries now infected.
Globally more new cases in the rest of the world than in China.
WHO have not yet classified COVID-19 as a pandemic.
WHO Risk assessment for the world is HIGH and for China VERY HIGH