14 Responses to “New H1N1 flu projections: second USA detailed report”

1. Animation of the evolution of Mexican Flu in the Continental United States « GLEaMviz.org says:

   May 1, 2009 at 8:36 pm

   [...] « Mexican Flu projections: second USA detailed report [...]
2. Linda Watson says:

   May 1, 2009 at 8:36 pm

   Can you give predictions for the number of flu cases/sick people for the same time periods? I can see the spread by state and country (based on your analysis) but would like to know the best and worst case scenario by number of infected people. I’m sure you have looked at the data in a number of ways. Is your data public and where do I look?

   My concern is that perhaps we are not acting quickly enough to slow the spread. I know that the economy is important and people need to work, shop, etc. However, I am wondering if simple things like closing schools early would impact the spread. Schools close for summer break in two weeks. The children have completed their standardized testing and are coasting until summer. They have completed their required curriculum for the year. Can you make predictions based on closing schools and distancing (not attending group events) and compare it to not closing schools and not distancing (attending group events without change)? Can you do these prediction based upon number of cases/sick people? Can you also predict number of deaths for both scenarios?

   Will you please email a response to lin.watson@yahoo.com

   Thanks,
   Linda
3. Lina says:

   May 1, 2009 at 8:46 pm

   OMG! The swine flu is red on the state right next to where I live! Will I die?
4. Karen Y says:

   May 1, 2009 at 9:09 pm

   WHY HAS TRAVEL NOT BEEN RESTRICTED FROM MEXICO TO THE U.S. We know it started in Mexico why the hell haven’t we stopped them from coming in? This is not just the flu, it is something we have NO VACCINE for!
5. Vivica says:

   May 1, 2009 at 9:19 pm

   There are now t2o known cases of the swine flu in Florida. Governor Charlie Christ just announced it with the help of the Surgeon General.
6. Mark Malnati says:

   May 1, 2009 at 9:25 pm

   I’m an actuary at New York Life tracking the flu’s advance. Obviously if this starts turning into 1918 we want as much advance notice as we can get.

   Are you projecting cases, reported cases, both ?
   What value(s) are you using for the infectiousness of this flu ?

   Thanks
7. Linda says:

   May 1, 2009 at 11:19 pm

   Why are there two or more versions of the study? The site link says for ‘public information’ click the link? Why can’t the public see the other version(s) of the study?
8. Matt says:

   May 2, 2009 at 2:55 am

   This is so ridiculous, South Carolina already has 11 confirmed cases and Virginia has known. They have Virginia with them by the end, and NONE in SC, WHICH ALREADY HAS 11, and 42 more being tested. This is snake oil science at its worst.
9. gleamviz says:

   May 2, 2009 at 5:11 pm

   Dear visitors,

   We welcome your comments and we want to apologize for not being able to respond on each and every of the often interesting and relevant questions and remarks posed in your comments. We do however want to address some in the following:

   Linda Watson: We do indeed look at the data in a number of ways. Containment measures as decided by health authorities will be integrated in futures updates. We actively consider social distancing, but surely you will understand that devising meaningful model parameters is a non-trivial exercise. We are also sure that you’ll understand that we have to careful on what we make public and that we cannot satisfy all requests as our resources are currently stretched thin.

   Lina: We did run a very special simulation to consider your particular case and we are happy to report that you will not die.

   Karen Y: See http://www.newscientist.com/article/dn17046

   Mark Malnati: We are projecting cases. The number of reported cases will generally be lower. The R0 parameter in the worst case scenarios is 1.9, meaning that each infected person will, on average, infect 1.9 other persons.

   Linda: Each report is based on simulations run with initial conditions derived from the data available to us. As new information becomes available we update the model and run the simulations again. Furthermore, as new cases are confirmed we have to integrate these in the simulations as well. This is why we have and will post updates on a regular basis. As to your second question: I do not understand what you refer to with “The site link …”.

   Matt: We are sorry that our reports do no meet your expectation. This is, however, mainly due to a mismatch of your expectations and what these reports actually have to offer. As stated in our disclaimers (first listed here, now provided on this separate page), the results are based on computational models and have to be considered only as an extra source of information and not as the reality of the epidemic unfolding. In other words: we never claimed that our “snake oil” will cure all your diseases, so we dismiss your bite as uncalled for.
10. Don Tosaw says:

    May 3, 2009 at 1:39 am

    Since your projections are based on numbers of confirmed cases and this number is known to be significantly smaller than the actual number of cases, isn’t this projection somewhat misleading?

    My question assumes of course, that a significant percentage, if not a majority of probable cases are actual cases. After all, the mayor of New York has stated that the numbers of cases in that city are already likely to be in the hundreds, as they’ve decided not to send in specimens for many probable cases, as they do not want to waste the resources.

    Thanks for your time and for providing this analysis.
11. Don Tosaw says:

    May 3, 2009 at 2:35 am

    I’ve noticed that the number of confirmed cases for New York hasn’t changed in several days. I assume they must have stopped sending in specimens of probable cases. In fact the number reported on April 29th and again on April 30th was 51 and the number reported yesterday and today was 50. The number of confirmed cases for New York reported on the CDC website is therefore misleading at best, or am I missing something here?
12. Carl says:

    May 3, 2009 at 7:14 am

    First, I’d like to commend you on your excellent work. While the authorities (CDC, WHO etc) continue to stick their head in the sand and refuse to come up with any prediction whatsoever (despite having decades of research experience on the subject matter as well as access to public funding), you guys are not only trying make sense of this unfortunate event within such short period of time - but also going public with your findings. Good work!

    However, any mathematical model - nor matter how accurate or well designed - is only as good as the data that is being fed into it. Unfortunately, the data you guys are getting is poor for three reasons. First, the nature of this disease is such that it is virtually indistinguishable from regular seasonal flu (at least, in the early stages), which means that there may be more sick people running around the world than what the governments and health authorities are actually telling us. Second, it is almost pointless to go by the number of confirmed cases, as the WHO is dreadfully slow and inconsistent in the way they handle the ‘backlogs’. Third, some health authorities are now suggesting that up to one third of the carriers may not even show symptoms at all - but can still infect others (though whether that is true remains to be seen). To add to the confusion, the Mexican government has (for better or worse) ceased reporting new cases of infection entirely, so your data may become even staler than it already is.

    So as a fellow researcher who makes a living out of publishing prediction data, but has to live with the not-so-pleasant consequence of getting it wrong (which happens from time to time, nobody is perfect!), my suggestion is this: perhaps you can run a scenario analysis based on different sets initial conditions, with the base case scenario being the official data provided by health authorities. The worst case might assume some sort of multiplier to the reported cases (say, ten times). I understand that this doesn’t sound as exciting as making statements like ‘our calculation shows xx infections by May 17th’, but it’s virtually impossible to make any kind of single point prediction with any degree of accuracy. At the very least, the scenario simulations will allow us to get a better feel for the degree of perbutation based on different sets of initial conditions.

    As I mentioned earlier, I do think your team is on to something, and regardless of some of the nasty comments you’ve been getting on this post (it’s normal, everyone’s a critic!) , this project provides valuable insight for the public who is being kept in the dark - as they often are at times like this. I am not sure how long it takes for you to run your models, but my opinion is that an extra bit of information will go a long way in adding value to your hard work.

    Again, thanks for your great work, and I look forward to seeing any sort of scenario analysis results.
13. J says:

    May 3, 2009 at 7:46 pm

    Do you take into account that most states do not reccommend that schools be closed until there is a confirmed case at a particular school, or there is a sibling at one school with a confirmed case, thus causing the other school to close. I understand it takes four days to get a test ready, so if a kid in the school has it, then most likely they have already spread it. Maybe I am overly cautious or uniformed, but it seems to me that schools, which are a vehicle for this to spread, should be closed. Are there any models that take into account that we are not mitigating this from being spread in our nation’s schools, colleges, and universities.
14. Mark Malnati says:

    May 4, 2009 at 5:18 pm

    Thank you for answering my questions. One thing you might consider, over the weekend we had our first instance of this strain jumping from humans back to pigs. (a Canadian farmer returned from a trip to Mexico and infected his flock) Keep up the good work!