Antiviral model series
revere | March 11, 2008I'm an advocate of using computer models to help us think about what might or could happen during various pandemic flu scenarios, but it is a technique with drawbacks. For one, it can suggest that some things might be possible that are either very difficult to do or aren't feasible. This happened in 2005 when some models were published in Science and Nature that suggested a pandemic could be nipped in the bud before it started. Most people thought that what was required was unrealistic but it put WHO in a bind. They had to marshal their resources to show they were willing to try or go down…
revere | March 4, 2008Press releases are the way a lot of scientific information is released today. Straight to the public, no peer review. This has advantages and disadvantages. The advantages are speed and directness. No filtering through reviewers, journal editors, colleagues. And of course that's the disadvantage, too, especially when the news comes from an interested party as it usually does in a press release. This is part of the interpretation of data these days. All that being said, the maker of Tamiflu, Hoffman - La Roche, has released data they have gathered from physicians treating cases of H5N1 in…
revere | June 24, 2007There's been a bit of a buzz about a paper by Australian researcher Jennifer McKimm-Breschkin at the Toronto flu meetings last week. McKimm-Breschkin told the gathering of 1500 flu obsessed scientists just what they didn't want to hear: that she and her colleagues had evidence from the laboratory that clade 2 H5N1 avian influenza virus isolated from birds in Indonesia were becoming resistant to the only oral antiviral effective against the virus, oseltamivir (Tamiflu). In comparison to clade 1 (southeast asian) virus from a few years back, the sensitivity was 20 to 30 times less.
We'll have…
revere | April 5, 2007[A series of posts explaining a paper on the mathematical modeling of the spread of antiviral resistance. Links to other posts in the series by clicking tags, "Math model series" or "Antiviral model series" under Categories, left sidebar. Preliminary post here. Table of contents at end of this post.]
This is the last in a long series attempting to explain a recent paper by Lipsitch et al. on mathematical modeling of the effects on influenza control of antiviral resistance, published in PLoS Medicine in January 2007. Modeling is a valuable technique but for most readers, even most scientists…
revere | April 4, 2007[A series of posts explaining a paper on the mathematical modeling of the spread of antiviral resistance. Links to other posts in the series by clicking tags, "Math model series" or "Antiviral model series" under Categories, left sidebar. Preliminary post here. Table of contents at end of this post.]
We have now gone through the entire paper on modeling the impact of antiviral resistance in an influenza control program, by Lipsitch et al., published in PLoS Medicine. Since a number of assumptions were made, we take some time to consider what effects they have on the model's results. In the…
revere | April 4, 2007Just as we are preparing to wind up our marathon series of posts on a mathematical model of antiviral resistance, a new paper has appeared in the Journal of the American Medical Association (JAMA) with data on antiviral resistance from Japan, the country that uses more Tamiflu and Relenza (the two available neuraminiase inhibitor antiviral drugs) than any other. It turns out the accompanying Editorial in JAMA specifically mentions the modeling paper and its results as a key to understanding the significance of this work. So all our labor has not been in vain. Here's more.
Our eye was caught…
revere | April 3, 2007[A series of posts explaining a paper on the mathematical modeling of the spread of antiviral resistance. Links to other posts in the series by clicking tags, "Math model series" or "Antiviral model series" under Categories, left sidebar. Preliminary post here. Table of contents at end of this post.]
We conclude our section by section examination of the mathematical modeling paper by Lipsitch et al., published in PLoS Medicine. We have finally arrived at the final section, Discussion (starting on page 8 of the .pdf version). In the second post we said many scientists read only the Abstract,…
revere | April 2, 2007[A series of posts explaining a paper on the mathematical modeling of the spread of antiviral resistance. Links to other posts in the series by clicking tags, "Math model series" or "Antiviral model series" under Categories, left sidebar. Preliminary post here. Table of contents at end of this post.]
In this post we explain the remaining results presented in the paper by Lipsitch et al. in published in PLoS Medicine (the subsections headed, "Effects of resistance on epidemic size" and "Dependence of outcomes o fitness cost and intensity of control" on page 6).
These sections and the…
revere | April 1, 2007[A series of posts explaining a paper on the mathematical modeling of the spread of antiviral resistance. Links to other posts in the series by clicking tags, "Math model series" or "Antiviral model series" under Categories, left sidebar. Preliminary post here. Table of contents at end of this post.]
We now take a look at what happens in the model when we vary the intensity of prophylaxis and treatment. The model treats the fraction of those prophylaxed, fp, and those treated, fT, separately, but for illustrative purposes the paper sets these two figures at the same number. In the previous…
revere | March 31, 2007[A series of posts explaining a paper on the mathematical modeling of the spread of antiviral resistance. Links to other posts in the series by clicking tags, "Math model series" or "Antiviral model series" under Categories, left sidebar. Preliminary post here. Table of contents at end of this post.]
We've spent a long time in the previous posts looking inside the black box of a mathematical model for the spread and consequences of antiviral resistance to Tamiflu (described in the paper by Lipsitch et al., published in PLoS Medicine). From the last post you will recall the authors assume it…
revere | March 30, 2007[A series of posts explaining a paper on the mathematical modeling of the spread of antiviral resistance. Links to other posts in the series by clicking tags, "Math model series" or "Antiviral model series" under Categories, left sidebar. Preliminary post here. Table of contents at end of this post.]
Now we are almost ready to run the model described in the paper, "Antiviral resistance and the control of pandemic influenza," by Lipsitch et al., published in PLoS Medicine. If you have been following up to this point, you will know the model described in the Methods section is a homogeneous…
revere | March 29, 2007[A series of posts explaining a paper on the mathematical modeling of the spread of antiviral resistance. Links to other posts in the series by clicking tags, "Math model series" or "Antiviral model series" under Categories, left sidebar. Preliminary post here. Table of contents at end of this post.]
In the previous posts we have walked through the Introduction and Methods sections of the paper, "Antiviral resistance and the control of pandemic influenza," by Lipsitch et al., published in PLoS Medicine. The Methods section sets out the detailed model, which is summarized in the Figure in the…
revere | March 28, 2007[A series of posts explaining a paper on the mathematical modeling of the spread of antiviral resistance. Links to other posts in the series by clicking tags, "Math model series" or "Antiviral model series" under Categories, left sidebar. Preliminary post here. Table of contents at end of this post.]
We need to finish the Methods section of the mathematical model in the paper, "Antiviral resistance and the control of pandemic influenza," by Lipsitch et al., published in PLoS Medicine. Then we can move on to Results. In this post we will deal mainly with paragraphs 3 and 4 of Methods on page 3…
revere | March 27, 2007[A series of posts explaining a paper on the mathematical modeling of the spread of antiviral resistance. Links to other posts in the series by clicking tags, "Math model series" or "Antiviral model series" under Categories, left sidebar. Preliminary post here. Table of contents at end of this post.]
We are now almost through with the mathematical part of the model in the paper, "Antiviral resistance and the control of pandemic influenza," by Lipsitch et al., published in PLoS Medicine (once Methods section is done, we will examine the Results, which are not mathematical but epidemiological…
revere | March 26, 2007[A series of posts explaining a paper on the mathematical modeling of the spread of antiviral resistance. Links to other posts in the series by clicking tags, "Math model series" or "Antiviral model series" under Categories, left sidebar. Preliminary post here. Table of contents at end of this post.]
We continue our examination of the paper, "Antiviral resistance and the control of pandemic influenza," by Lipsitch et al., published in PLoS Medicine. We have gotten to the point where our population is divided into five categories. We follow the course of the epidemic on each of its days by…
revere | March 25, 2007[A series of posts explaining a paper on the mathematical modeling of the spread of antiviral resistance. Links to other posts in the series by clicking tags, "Math model series" or "Antiviral model series" under Categories, left sidebar. Preliminary post here. Table of contents at end of this post.]
In this post we begin our look at the mathematical part of the model in the paper, "Antiviral resistance and the control of pandemic influenza," by Lipsitch et al., published in PLoS Medicine. The main model is presented in the first four paragraphs of the Methods section.
The Model: view from 50…
revere | March 24, 2007[A series of posts explaining a paper on the mathematical modeling of the spread of antiviral resistance. Links to other posts in the series by clicking tags, "Math model series" or "Antiviral model series" under Categories, left sidebar. Preliminary post here. Table of contents at end of this post.]
The Modeling Series (click Math Modeling Series under Categories in the left sidebar) is a moving target for me. Even though the first draft of the post you read each day was written at least three weeks earlier, each has also been freshly worked on as I go back and tinker and adjust and try to…
revere | March 24, 2007[A series of posts explaining a paper on the mathematical modeling of the spread of antiviral resistance. Links to other posts in the series by clicking tags, "Math model series" or "Antiviral model series" under Categories, left sidebar. Preliminary post here. Table of contents at end of this post.]
We are almost ready to begin a detailed examination of the mathematical model presented in the paper, "Antiviral resistance and the control of pandemic influenza," by Lipsitch et al., published in PLoS Medicine. The main model is presented in the first four paragraphs of the Methods.
Some…
revere | March 23, 2007[A series of posts explaining a paper on the mathematical modeling of the spread of antiviral resistance. Links to other posts in the series by clicking tags, "Math model series" or "Antiviral model series" under Categories, left sidebar. Preliminary post here. Table of contents at end of this post.]
As promised, this post will start a detailed examination of the paper by Lipsitch et al., "Antiviral resistance and the control of pandemic influenza," published in PLoS Medicine, section by section. We hope you have your own copy, available here (see previous post for more details). We'll start…
revere | March 22, 2007[A series of posts explaining a paper on the mathematical modeling of the spread of antiviral resistance. Links to other posts in the series by clicking tags, "Math model series" or "Antiviral model series" under Categories, left sidebar. Preliminary post here. Table of contents at end of this post.]
In this post we start to dig into a mathematical model of antiviral resistance in influenza. The modern era of mathematical modeling started early in the last century with attempts to understand malaria spread, almost exactly 100 years ago. For the first 50 of those years scientists used pure…