How Dangerous is Novel Coronavirus ?

Novel coronavirus (aka Wuhan virus or 2019-nCoV) is a coronavirus family member, firstly identified in Wuhan Hubei province of China. It designated after the first cases developed a pneumonia without responding existing treatments. Origin of the first and majority of all cases points a local market that trading wild animals.

Some cases reported in overseas countries who never been in that origin market, Wuhan city or even any part of China can be shown as the evidences for human-to-human transmissions. Authors believe the virus can spread far and wide by public local/international transports. Risk could be higher while the first cases appeared just before Chinese new moon year.

After a litte summary, today I would like to share some statistics instead of a science-fiction scripts to analyse the size of the dangerousness.

According to the officials reports and verifiable news we have following number of cases in China by the date 2020.01.28

Case StatusNumber of Cases
Confirmed (Cumulative)5974
Suspected (Current)9239
Quarantined (Current)59990
Quarantined (Total Cumulative)65537
Deaths (Cumulative)132

The proportion a suspected case to turning out to a confirmed case can be estimated even while the number of discharged cases and released are not clear yet. Andy Chen at page assumes that rates as;

A decent proportion of these are going to turn out to be coronavirus. If we consider these numbers now, and we assume
90% of suspected cases turn out to be coronavirus.
20% of people being medically monitored turn out have caught it as well.

Andy Chen Jan 25

Within this numbers to calculate the case-fatality rate of this outbreak we should know total number of infected cases and total number of deaths. It should be Confirmed cases + (Suspected cases X 90%) + ( Quarantined cases X 20)

Estimated infected cases = 5974 + (9239 * 0.9 )+ ( 59990 * 0.2) = 26287
Total Death = 132

Estimated CFR (Case Fatality Rate) is percent (132/26287)*100 = 0.502%
This percentage has a little possibility to increase, due to some cases are may die in next days but currently they are counted as suspected/confirmed.
But in the other hand, it is more probably going to be a lower percentage if we widen the scope by adding
* Non-reported but infected cases,
* Infected but staying in home cases (due to curfew)
* Asymptomatic cases

As an example, approximately 33% of people with influenza are asymptomatic. That means even they do not aware that they were infected, and they were not used in the calculation of case fatality rate.

To analyse the worst possibility, if we calculate the CFR by using only confirmed cases and ignoring the all suspected, asymptomatic and monitored cases, the percentage is going to be (132/5974) * 100 = 2.2%

If we compare this percentages with SARS and MERS outbreaks which caused by the same members of coronavirus family,
* MERS fatality rate is 34%
* SARS fatality rate is 10%
* Novel fatality rate is between 0.5% – 2.2%

If we compare with influenza outbreaks CFR
* Spanish flu (H1N1) was 2%
* Bird flu (H5N1) was 2.5%
* Influenza A, typical pandemics was < 0.1%

Another statistics published at the currently shows 2.2% too based on only confirmed cases number, ignored quarantine and even suspected/waiting test results cases.
You can find a Transmission Rate (Ro) at this page which is also as important as the CFR. Currently shows 3.8 (means each case causes 3.8 more infected cases) But the arguments for the Ro calculation is not clear yet.

By this point, the numbers we have obviously show that Novel Coronavirus is not an ability to be end of humanity as claimed in some twitter posts. I assume that the CFR is going to be between 0.1 and 0.5% which is similar for a seasonal/typical flu.

I do not thing the Chinese Government precautions like suspending public transport or even quarantine is extraordinary when nothing was clear and the similar viruses like SARS and MERS were really horror stories. But at the end of a month, the Novel virus is not as danger as SARS/MERS.

I guess some news agencies titles “13 new death in China today” and some social media posts may aims more clicks but causes wrong impacts and panic for people. Currently we have a total number of death cases 132 in more than a month which is not significant while everyday 4000+ people are dying because of heart diseases in same China.

Every year an estimated 290,000 to 650,000 people die in the world due to complications from seasonal influenza (flu) viruses.

In order to evaluate this outbreak within the scientific metrics like case-fatality rate, mortality, transmission rate e.t.c. we need to wait more for clarifying status of current cases. These will turn out to released and death cases. Also there are some numbers to add calculations but we do not have yet like asymptomatic, not reported cases. But current number we have shows us most probably this is not deserve to be a red alarm. That’s why the WHO (world health organisation) has refused to declare a global emergency .