Control of COVID-19


Early dynamics of transmission and control of COVID-19: a mathematical modelling study



An outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to 95 333 confirmed cases as of March 5, 2020. Understanding the early transmission dynamics of the infection and evaluating the effectiveness of control measures is crucial for assessing the potential for sustained transmission to occur in new areas. Combining a mathematical model of severe SARS-CoV-2 transmission with four datasets from within and outside Wuhan, we estimated how transmission in Wuhan varied between December, 2019, and February, 2020. We used these estimates to assess the potential for sustained human-to-human transmission to occur in locations outside Wuhan if cases were introduced.
We combined a stochastic transmission model with data on cases of coronavirus disease 2019 (COVID-19) in Wuhan and international cases that originated in Wuhan to estimate how transmission had varied over time during January, 2020, and February, 2020. Based on these estimates, we then calculated the probability that newly introduced cases might generate outbreaks in other areas. To estimate the early dynamics of transmission in Wuhan, we fitted a stochastic transmission dynamic model to multiple publicly available datasets on cases in Wuhan and internationally exported cases from Wuhan. The four datasets we fitted to were: daily number of new internationally exported cases (or lack thereof), by date of onset, as of Jan 26, 2020; daily number of new cases in Wuhan with no market exposure, by date of onset, between Dec 1, 2019, and Jan 1, 2020; daily number of new cases in China, by date of onset, between Dec 29, 2019, and Jan 23, 2020; and proportion of infected passengers on evacuation flights between Jan 29, 2020, and Feb 4, 2020. We used an additional two datasets for comparison with model outputs: daily number of new exported cases from Wuhan (or lack thereof) in countries with high connectivity to Wuhan (ie, top 20 most at-risk countries), by date of confirmation, as of Feb 10, 2020; and data on new confirmed cases reported in Wuhan between Jan 16, 2020, and Feb 11, 2020.
We estimated that the median daily reproduction number (Rt) in Wuhan declined from 2·35 (95% CI 1·15–4·77) 1 week before travel restrictions were introduced on Jan 23, 2020, to 1·05 (0·41–2·39) 1 week after. Based on our estimates of Rt, assuming SARS-like variation, we calculated that in locations with similar transmission potential to Wuhan in early January, once there are at least four independently introduced cases, there is a more than 50% chance the infection will establish within that population.
Our results show that COVID-19 transmission probably declined in Wuhan during late January, 2020, coinciding with the introduction of travel control measures. As more cases arrive in international locations with similar transmission potential to Wuhan before these control measures, it is likely many chains of transmission will fail to establish initially, but might lead to new outbreaks eventually.
Wellcome Trust, Health Data Research UK, Bill & Melinda Gates Foundation, and National Institute for Health Research.
• View related content for this article
As of Feb 13, 2020, an outbreak of coronavirus disease 2019 (COVID-19) has resulted in 46 997 confirmed cases.1
The outbreak was first identified in Wuhan, China, in December, 2019, with most early cases being reported in the city. Most internationally exported cases reported to date have history of travel to Wuhan.2
In the early stages of a new infectious disease outbreak, it is crucial to understand the transmission dynamics of the infection. Estimation of changes in transmission over time can provide insights into the epidemiological situation3
and identify whether outbreak control measures are having a measurable effect.4
,  5
Such analysis can inform predictions about potential future growth,6
help estimate risk to other countries,7
and guide the design of alternative interventions.8
However, there are several challenges to such analyses, particularly in real time. There can be a delay to symptom appearance resulting from the incubation period and delay to confirmation of cases resulting from detection and testing capacity.9
Modelling approaches can account for such delays and uncertainty by explicitly incorporating delays resulting from the natural history of infection and reporting processes.10
Additionally, individual data sources might be biased, incomplete, or only capture certain aspects of the outbreak dynamics. Evidence synthesis approaches, which fit to multiple data sources rather than a single dataset (or datapoint) can enable more robust estimation of the underlying dynamics of transmission from noisy data.11
,  12
Combining a mathematical model of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission with four datasets from within and outside Wuhan, we estimated how transmission in Wuhan varied between December, 2019, and February, 2020. We used these estimates to assess the potential for sustained human-to-human transmission to occur in locations outside Wuhan if cases were introduced.

52 thoughts on “Control of COVID-19

  1. years says:

    Great website. Lots of useful information here. I am sending
    it to a few buddies ans additionally sharing in delicious.

    And certainly, thank you on your sweat!

  2. vide18 says:

    Wonderful blog! I found it while browsing on Yahoo News.

    Do you have any suggestions on how to get listed in Yahoo News?
    I’ve been trying for a while but I never seem to get
    there! Many thanks

  3. se says:

    Normally I don’t read post on blogs, but I would like to say that this write-up very
    forced me to check out and do so! Your writing style has been surprised me.
    Thanks, quite great post.

  4. incebigcock14 says:

    I’ve been browsing online more than 3 hours today, yet I never
    found any interesting article like yours. It is pretty worth enough for me.
    Personally, if all site owners and bloggers made good content as you did,
    the internet will be a lot more useful than ever before.

  5. inch says:

    Hello! Someone in my Myspace group shared this website with us so I came
    to give it a look. I’m definitely loving the information. I’m bookmarking and will be tweeting this to my followers!
    Exceptional blog and great design.

  6. time says:

    Hi, I do think this is a great website. I stumbledupon it 😉 I’m going to revisit yet again since I book-marked it.

    Money and freedom is the greatest way to change, may you be rich and continue to help

  7. in says:

    Hi, I do believe this is an excellent website. I stumbledupon it
    😉 I’m going to revisit yet again since i have bookmarked it.
    Money and freedom is the greatest way to change, may you be rich and continue to help others.

  8. video18 says:

    I have been exploring for a little bit for any high
    quality articles or weblog posts in this kind of space . Exploring in Yahoo I finally stumbled upon this site.
    Studying this information So i’m happy to show that I’ve an incredibly
    good uncanny feeling I came upon exactly what I needed.
    I so much definitely will make sure to do not omit this web site
    and give it a look on a relentless basis.

  9. ki says:

    Cool blog! Is your theme custom made or did you download it from somewhere?
    A design like yours with a few simple tweeks would really make
    my blog jump out. Please let me know where you got your
    design. Kudos

  10. ki says:

    Very nice post. I just stumbled upon your blog and wished to say
    that I’ve truly enjoyed browsing your blog posts. In any case I’ll be subscribing to your feed and
    I hope you write again soon!

  11. disappears says:

    I’m impressed, I must say. Seldom do I come across
    a blog that’s both equally educative and amusing, and without a doubt, you have
    hit the nail on the head. The issue is something not enough people are speaking intelligently
    about. I’m very happy I found this during my search
    for something relating to this.

  12. 20 says:

    Someone necessarily assist to make severely posts I would state.
    This is the very first time I frequented your
    web page and up to now? I surprised with the analysis you made to create this actual post extraordinary.
    Great task!

  13. sal says:

    Hi my friend! I want to say that this article is awesome, nice written and include almost all
    vital infos. I would like to peer extra posts like this .

  14. ladki says:

    What’s Taking place i am new to this, I stumbled upon this
    I have discovered It absolutely helpful and it has helped me out loads.
    I hope to give a contribution & aid other users like its aided me.
    Great job.

  15. hindi says:

    Greetings! I know this is somewhat off topic but I was
    wondering if you knew where I could find a captcha plugin for my comment form?
    I’m using the same blog platform as yours and
    I’m having problems finding one? Thanks a lot!

  16. ladki says:

    I will right away snatch your rss as I can not to
    find your email subscription link or e-newsletter
    service. Do you’ve any? Kindly permit me recognize so that
    I could subscribe. Thanks.

  17. video18 says:

    I really love your website.. Great colors & theme.
    Did you make this amazing site yourself? Please reply back
    as I’m trying to create my own site and want to learn where you got this from or just what the theme is named.
    Thank you!

  18. porn14 says:

    I have been browsing online more than 2 hours today, yet I never found any interesting
    article like yours. It’s pretty worth enough for me.
    Personally, if all web owners and bloggers made good content as you did, the web will be much more useful than ever before.

  19. says:

    Appreciating the hard work you put into your website and in depth information you
    provide. It’s great to come across a blog every once in a while that isn’t the same old rehashed information. Fantastic
    read! I’ve bookmarked your site and I’m including your RSS feeds to my Google account.

  20. kobe byrant shoes says:

    My husband and i were quite delighted Peter could round up his studies with the precious recommendations he got through the weblog. It is now and again perplexing just to be handing out key points which people might have been making money from. And we also discover we have got the blog owner to give thanks to for that. The explanations you made, the easy blog navigation, the friendships your site help to foster – it’s most astounding, and it is making our son and us recognize that this concept is fun, and that’s pretty essential. Thank you for all the pieces!

  21. russell westbrook shoes says:

    I’m just commenting to let you understand what a remarkable discovery my princess enjoyed using your site. She discovered a good number of issues, not to mention how it is like to have an awesome coaching style to make folks very easily completely grasp some problematic things. You undoubtedly exceeded my expectations. Thank you for providing the important, healthy, educational and cool guidance on this topic to Sandra.

  22. jordan shoes says:

    I needed to compose you one tiny observation in order to thank you very much once again regarding the stunning tactics you have featured above. It has been so remarkably generous of people like you giving extensively what exactly many of us could have made available for an e book to make some money on their own, specifically considering the fact that you could have done it if you desired. Those basics additionally served as the great way to realize that the rest have the same dream really like my personal own to know more and more in respect of this issue. I’m sure there are millions of more fun situations ahead for many who looked at your site.

  23. curry shoes says:

    I wish to point out my love for your generosity supporting people that should have help on this particular content. Your very own commitment to passing the solution along came to be quite advantageous and have specifically helped somebody just like me to reach their ambitions. Your own helpful publication can mean a whole lot to me and a whole lot more to my colleagues. Warm regards; from all of us.

  24. cheap jordans says:

    I needed to send you this tiny note just to say thanks yet again for these marvelous tactics you have shown on this website. It was so incredibly generous of people like you giving unhampered all most of us would’ve advertised for an e-book to make some money for themselves, chiefly now that you might well have done it if you ever decided. These solutions additionally acted to become a good way to be certain that other people online have the identical keenness the same as my personal own to know the truth a whole lot more regarding this matter. I am sure there are numerous more enjoyable sessions up front for those who examine your site.

  25. pg 1 says:

    Thanks a lot for providing individuals with a very brilliant opportunity to read in detail from here. It’s always so superb and as well , stuffed with a great time for me and my office fellow workers to search your site on the least three times a week to find out the latest things you will have. Of course, I am also at all times satisfied with all the magnificent creative concepts served by you. Certain 4 ideas on this page are really the simplest we’ve had.

  26. bape says:

    I simply wished to appreciate you all over again. I am not sure what I would have created without the actual tips shared by you on that topic. It was before a very depressing circumstance in my opinion, but witnessing a specialised mode you handled that made me to cry for contentment. I’m happy for the work and thus wish you recognize what an amazing job you are undertaking educating other individuals via your site. Most likely you’ve never come across any of us.

  27. golden goose outlet says:

    I am just commenting to let you know what a extraordinary discovery my wife’s child had visiting your web site. She realized a lot of pieces, including what it’s like to have an amazing giving heart to let other individuals with no trouble know several impossible issues. You undoubtedly exceeded visitors’ expected results. I appreciate you for providing such priceless, trusted, informative and also easy tips about that topic to Ethel.

Leave a Reply

Your email address will not be published. Required fields are marked *