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#Post#: 30--------------------------------------------------
spread modeling
By: gsgs Date: January 31, 2020, 2:00 pm
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In our baseline scenario, we estimated that the basic
reproductive number for 2019-nCoV was 2·68 (95% CrI
2·47–2·86) and that 75 815 individuals (95% CrI
37 304–130 330) have been infected in Wuhan as
of Jan 25, 2020. The epidemic doubling time was 6·4 days (95%
CrI 5·8–7·1). We estimated that in the baseline scenario,
Chongqing, Beijing, Shanghai, Guangzhou, and Shenzhen had
imported 461 (95% CrI 227–805), 113 (57–193), 98
(49–168), 111 (56–191), and 80 (40–139)
infections from Wuhan, respectively. If the transmissibility of
2019-nCoV were similar everywhere domestically and over time, we
inferred that epidemics are already growing exponentially in
multiple major cities of China with a lag time behind the Wuhan
outbreak of about 1–2 weeks.
HTML https://flutrackers.com/forum/forum/-2019-ncov-new-coronavirus/-2019-ncov-studies-research-academia/826405-lancet-nowcasting-and-forecasting-the-potential-domestic-and-international-spread-of-the-2019-ncov-outbreak-originating-in-wuhan-china-a-modelling-study
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the Chinese government, the Chinese experts, the WHO director
general
were confident that they could stop the spread.
This looks unlikely considering the modeling studies, current
ones and all those
about H5N1 in 2005-2009 and the experiences from influenza
pandemics.
Did they really believe this ?
Did they just say this to avoid panic, to keep the social order
and
economic structures ? Sacrificing credibility for a gain of a
few days or weeks.
#Post#: 69--------------------------------------------------
Re: spread modeling
By: epsilon Date: February 7, 2020, 10:56 am
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[quote]
Did they really believe this ?
Did they just say this to avoid panic, to keep the social order
and
economic structures ? Sacrificing credibility for a gain of a
few days or weeks.
[/quote]
Those are very good questions that I also often ask myself when
reading such official/media statements. But it is even the
experts that often underplay and trivialise when interviewed.
This is not to say that alarmism and panic is better. But the
amount of alertness to a threat should be not only proportional
to its risk but also to the amount of worst case damage it could
do (and for pandemics, this is very, very high damage potential)
I think that high CFR pandemic respiratory viruses are the most
under estimated threat to our society whereas other threats like
nuclear power, natural disasters, terrorism, wars are
consistently over-represented.
#Post#: 92--------------------------------------------------
Re: spread modeling
By: epsilon Date: February 10, 2020, 12:56 pm
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New study puts case doubling rate at 2.9 days (half than
previous estimates !)
HTML https://www.medrxiv.org/content/10.1101/2020.02.06.20020941v1
[quote]
the early outbreak of 2019-nCoV could have been spreading much
faster in Wuhan than previous estimates.
[/quote]
This is very concerning (but is consistent with R0=3 and the
recently published very short incubation period of 3 days).
This means not only does the epidemic spread twice as fast as
presumed, but it means that spread is exponentially twice as
fast.
Example: increase in number of cases after 4 weeks:
previous estimate (case doubling 7 days) : 16 fold increase
(2^4)
New estimate (doubling every 3 days) : 1.000 fold increase
(2^10)
This explosive growth perfectly explains why Wuhan got
overwhelmed so quickly.
If we continue to understimate this virus in our countries
outside China we are prone to the same playbook.
#Post#: 94--------------------------------------------------
Re: spread modeling
By: gsgs Date: February 10, 2020, 11:44 pm
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obviously it has changed
---------------------------------------
7.2 days here:
HTML https://github.com/blab/ncov-phylodynamics
> We estimate an exponential doubling time of 7.2 (95% CI
5.0-12.9) days. We arrive at a median
> estimate of the total cumulative number of worldwide
infections as of Feb 8, 2020, of 55,800
> with a 95% uncertainty interval of 17,500 to 194,400.
Importantly, this approach uses genome
> data from local and international cases and does not rely on
case reporting within China.
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