BREAKING: UAE closing all schools for at least 4 weeks due to coronavirus - state media

— BNO Newsroom (@BNODesk) March 3, 2020

WHO today said globally 3.4% of Covid19 cases had died. It does seem high to me but at the moment WHO seem to believe it.

Many countries are doing this now. Will the UK? 

Good question.

Prob means  hospitalisation not required  but how far down from that is "mild" ?

It is correct currently:

Coronavirus Cases: 92,809
Deaths: 3,164

https://www.worldometers.info/coronavirus/

What surprises me is I thought the expectation was that the mortality rate would be down to 1% to 2% due to the non-inclusion of mild cases. It now appears the WHO is saying there are very few which fit into that category.

The 3.4% will change as more cases are included.  As others have noted, the mortality rate is skewed by the high figure in Wuhan.  

It is inconceivable, given the range of symptoms, that there aren't any cases where the illness was so mild that the person didn't report it (take the early UK case arising from the visit to Singapore).

Your suggested range of 20-60 x worse than 'seasonal flu' almost certainly doesn't take into account the effect of the vaccine. In terms of virulence you would need to allow for that; without the protection for vulnerable groups and elderly flu would be much worse.

In some countries patients immediate family,  friends are tested even if they aren't showing symptoms.  If they test positive and never go on to show symptoms then you can measure non-symptom cases. Not an exact science though I agree.

I'm also puzzled by this:

First, COVID-19 does not transmit as efficiently as influenza, from the data we have so far.

https://www.who.int/dg/speeches/detail/who-director-general-s-opening-remarks-at-the-media-briefing-on-covid-19---3-march-2020

I thought it was supposed to be more transmissible than flu.

This was discussed on the radio this afternoon in the context of young people: it was said that it is quite usual for viruses to have negligible effects of children so there must be some cases which are unreported. Obviously the WHO can't include them in official data because there are no official figures - but that doesn't mean there aren't any.

What if you have the virus and don’t get tested? You cannot be included in statistics, therefore current statistics can only be based on conformed cases not the unknown number of undiagnosed cases. If you had Covid-19 would you choose to go and get tested? If you did would it change the treatment or advice you received if your symptoms were mild?

As for blanket closing of schools? I certainly hope not.

I am sure there are some but the message from the WHO today seems to be saying there are very few. In fact not enough to make a measurable difference to the stats. It's possible  I have misunderstood so please don't shoot the messenger. 

The report in your link refers to 1% infected but showing no symptoms, which I guess fits the reference to 'very low'.

But, as you would say, it's an unknown unknown, so very hard to tell. But that report talks about more widespread testing to identify who may have antibodies, which would clearly indicate exposure but negligible symptoms (except, obviously, where that person had been treated/hospitalised).

In the UK I would phone 111 and take their guidance. 

Fair enough but I suspect not everyone would and I also suspect there are countries which have no 111 equivalent.

My wife had flu symptoms last week and just worked her way through it. We had no thought to phoning 111.

NEW: U.S. death toll from coronavirus rises to 7 after Washington resident who died 6 days ago was found to have been infected - NYT

— BNO Newsroom (@BNODesk) March 3, 2020

It's a moot point. I've not had a cold for perhaps 4 or 5 years and flu only once in my life. Were I now to develop symptoms which could be corona I would be tempted to call 111. I go to a local gym 3 times per week and use the bars, restaurants and coffee shops in town at times.

 Corona Cherryade was what we drank in the Heatwave of 76 whilst on balecart. Cracking stuff.

Indeed. The relatively high proportion of asymptomatic carriers of covid19 in the under 20 age group combined with that cohort's propensity to mix more socially will likely give rise to quite sizeable trenches of unreported cases. 

You haven’t had a cold for FIVE years?! 

What the hell am I doing wrong? 

Given that nearly all of the UK's cases have flown in, there's no sign of one person infecting many others on the flight, otherwise we would have hundreds or thousands of cases by now. I don't know how much 'flu would achieve that.