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发帖数: 4637 | 1 https://cmmid.github.io/ncov/wuhan_early_dynamics/index.html
Analysis and projections of transmission dynamics of nCoV in Wuhan
Adam Kucharski. I am an Associate Professor and Sir Henry Dale Fellow at the
London School of Hygiene & Tropical Medicine, where I work on mathematical
analysis of infectious disease oubreaks.
07 February, 2020
Contributors: Adam Kucharski, Tim Russell, Charlie Diamond, Yang Liu, CMMID
nCoV working group, John Edmunds, Sebastian Funk, Rosalind Eggo.
Key results
• We estimated that the median effective basic reproduction number, Rt
, had likely been fluctuating between 1.6-3.1 prior to travel restrictions
being introduced on 23rd Jan (Figure 1F). (The effective reproduction number
is the average number of secondary cases generated by a typical infectious
individual at a given point in time, assuming a fully susceptible population
).
• If Rt continues to vary as it has in Wuhan, we projected that the
outbreak would peak in mid-to-late-February (Figure 1E). There is
substantial uncertainty about what the exact height and timing of the peak
might be. However, our projections aligned reasonably well with observed
confirmed cases so far in Wuhan in early February (Figure 2F) - as we get
more data in the coming days, we will be able to refine these projections.
• Based on the median reproduction number observed during January
before travel restrictions were introduced, we estimated that a single
introduction of 2019-nCoV with SARS-like or MERS-like individual-level
variation in transmission would have a 20–30% probability of causing a
large outbreak (Figure 2A). Assuming SARS-like variation and Wuhan-like
transmission, we estimated that once more than three infections have been
introduced into a new location, there is an over 50% chance that an outbreak
will occur (Figure 2B). | S*******l
发帖数: 4637 | 2 武汉总计50万人感染，绝大多数无症或轻症自愈未被统计。最终死亡率远小于1%。 | S*******l
发帖数: 4637 | 3 https://www.bloomberg.com/news/articles/2020-02-08/virus-outbreak-in-wuhan-
may-soon-peak-with-more-than-5-infected
The new coronavirus might have infected at least 500,000 people in Wuhan,
the Chinese city at the epicenter of the global outbreak, by the time it
peaks in coming weeks.
The typically bustling megacity, where the so-called 2019-nCoV virus emerged
late last year, has been in lockdown since Jan. 23, restricting the
movement of 11 million people. Recent trends in reported cases in Wuhan
broadly support the preliminary mathematical modeling the London School of
Hygiene & Tropical Medicine is using to predict the epidemic’s transmission
dynamics.
“Assuming current trends continue, we’re still projecting a mid-to-late-
February peak” in Wuhan, said Adam Kucharski, an associate professor of
infectious disease epidemiology, in an email Sunday. “There’s a lot of
uncertainty, so I’m cautious about picking out a single value for the peak,
but it’s possible based on current data we might see a peak prevalence
over 5%.”
That would potentially mean at least 1 in 20 people would have been infected
in the city by the time the epidemic peaks, Kucharski said, adding that
this may change if transmission patterns slow in coming days. |
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