bird flu
revere | March 28, 2007So the vaccine sharing summit in Jakarta is over and Indonesia says they will begin sharing virus again. The proviso is that they can't be shared with pharmaceutical companies until a vaccine-sharing agreement is hammered out with WHO and that will take an estimated 3 months. I'll be surprised if it is done that quickly, but Hope springs Eternal. Meanwhile the scientific community will be able to see the sequences (at least that's how I read it) and WHO can prepare seed strains but not distribute them. The agreement should also allow determination if any markers of antiviral resistance have…
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 27, 2007Indonesia, as usual, presents us with a dilemma. It is one of the least effective nations in dealing with their bird flu problem, exhibiting massive incompetence spiced by corruption. This has helped make them the bird flu epicenter of the world, with more deaths (by a long way) than any other nation and fast approaching Vietnam for most number of recorded cases. At the same time they have raised a legitimate issue: developing nations like Indonesia provide essential information to WHO on how to make effective vaccines against circulating influenza virus strains. WHO in turn shares the…
revere | March 26, 2007[Oh, my. Thanks to my readers at CIDRAP (tip of the hat!) I have become aware the story linked below on masks is an old one, something Crof at H5N1 calls a ghost story. The NewsNow aggregator I use has been doing this a lot lately, so I have been alert, but in this case I had it in my head there was a new mask report and I didn't check the date carefully. Everything I said in the post is still true, but it isn't new. In fact I said much the same thing when it first came out -- a year ago! Anyway, my apologies to readers. I hate to make mistakes like this.]
The National Academies os Science'…
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 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…
revere | March 21, 2007Indonesia has still to provide the WHO flu surveillance program with any H5N1 viral isolates since the first of the year. The issue is access to what will certainly be a scarce vaccine supply if a pandemic would start in the next five or or even ten years. The leading candidate for a pandemic strain at the moment is one that starts in Indonesia, the world's current hotspot for avian influenza both in poultry and people. So controlling access of vaccine makers to H5N1 isolate from within its borders recognizes they have something the rich countries that have the vaccine plants need. One reason…
revere | March 21, 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 use of antiviral drugs to prevent or manage a pandemic with influenza/H5N1 is both a mainstay of national and international pandemic plans and a source of controversy. Will there ever be sufficient doses to make a difference? If there were, could they be deployed and administered in time? If…
revere | March 20, 2007Tomorrow we begin a blog experiment, one we already judge has failed. In January Marc Lipsitch and his team at the Harvard School of Public Health published a splendid paper using a mathematical model to investigate the spread of antiviral resistance in the control of pandemic influenza. When we read it our first thought was to write a substantial blog post about the results. The paper was published in PLoS Medicine almost the same week as another mathematical model on spread through the air traffic system by Colizza et al. and the Colizza paper seemed to get most of the newswire notice. But…
revere | March 19, 2007In the old days doctors traded clinical pearls and experience face to face at medical meetings. With the internet and online publication we sometimes forget how important those personal information exchanges can be and often still are. Canadian Press's Helen Branswell (still the world's best flu reporter) now tells us that about 100 doctors with the most experience actually treating H5N1 infections will be meeting this week in southern Turkey to swap experiences:
Doctors who have treated H5N1 avian flu patients are meeting in a Turkish seaside town to try to find answers to the myriad…
revere | March 16, 2007In a paper in the Journal of Analytical Atomic Spectrometry [JAAS] (in case you haven't read your latest issue), I learned that bird migration patterns in Europe are still kind of hazy, despite the long standing and often intense interest on the part of birders and conservationists. It's just not an easy problem. Not being a birder myself, I didn't know this, nor did I have much interest in migratory patters of birds prior to bird flu. Now many of us have a newfound interest in it. Which is why a new method to figure out migratory bird patterns caught my eye.
The usual methods are both labor…
revere | March 15, 2007The problem of H5N1 contaminated food keeps coming up (see here and here). First it was, don't worry, stomach acid will kill it. Then it was, don't worry, you can't be infected through the intestinal tract. Then it was, don't worry, proper cooking kills the virus. The last of these is correct but isn't a reason not to worry. Somebody has to "properly cook" the food, so during preparation and food handling there is a risk of contact with possibly infectious material. Then there is "ready-to-eat" foods (like from the deli) which aren't cooked. Then there is contamination of animal foods that…
revere | March 14, 2007A few weeks ago an FDA advisory committee recommended approval of Sanofi-Aventis's prepandemic H5N1 vaccine, despite data that it required very large amounts of viral antigen (90 mcg) in two doses. At the time it seemed there were far better vaccines available or about to be available. What set this vaccine apart was that Sanofi had been making it to fill an order placed by the US Department of Health and Human Services (DHHS) and there was enough for 3.75 million people in the US stockpile, although because of elapsed shelf life that was down to about 3 million. Ninety micrograms is a lot…
revere | March 9, 2007Headlines in the last day: South Korea records seventh outbreak; Bird Flu Strikes Hanoi, Over 1,000 Chickens Culled; Bird flu erupts in Vietnam south; total 5 provinces infected; Bird flu found in 6 more areas of Afghanistan; Laos teenager dies from bird flu; Indonesian Villagers Hide Birds And Spread Flu; Myanmar takes preventive measures against bird flu; Southern China is epicenter of bird flu, U.S. researchers find; Suspicious bird flu deaths in Tehran's Pardisan Park; World experts in Kuwait as more bird flu cases detected; Dubai plans bird flu blood tests at airport -- Report: plan to…
revere | March 8, 2007The H5N1 in cats issue returns once again. We know felines, including big cats in zoos and domestic cats on city streets and backyards, can be infected with the virus. The assumption is they acquire it by eating infected birds, although we don't know the mode of transmission for sure. Now we have a story by the Bloomberg agency that a major study of feral cats is about to start in Indonesia:
For the cat study, scientists led by the United Nations' Food and Agriculture Organization will examine feline habits and collect blood samples to test for exposure to the H5N1 virus. Disease trackers aim…
revere | March 5, 2007If the best you can say about the human bird flu vaccine made by Big Pharma's Sanofi Aventis SA is that it is "better than nothing," are you even correct about that?
The Food and Drug Administration is considering a recommendation from an outside panel of expert advisers that it approve the Sanofi vaccine. Those experts endorsed the vaccine's safety and efficacy Feb. 27, but with a caveat: that it's only the first step in developing a way of successfully immunizing humans against the deadly H5N1 strain of bird flu.
Sanofi said it recognizes the vaccine is only an interim solution, since…
revere | March 4, 2007In December some people were wondering what had happened to bird flu. In January it came back, but there was hope it wouldn't be as bad as last year and that some of the control measures were working. Now February is behind us and we are seeing resignation in some quarters that we haven't made as much progress as we'd hoped:
Bird flu is on the march again across Asia as winter ends, but the battle against the killer virus is being hobbled by stark differences between the region's diverse countries, health experts warn.
While Vietnam and Thailand have been hailed as poster adverts in the fight…
revere | March 3, 2007When Indonesia withdrew from the longstanding system whereby countries shared influenza virus with WHO there was widespread consternation in the public health community. The sharing system has been used for many years to determine the candidate strains for the following year's vaccine. The regular seasonal flu vaccine has three components corresponding to the prediction of which of the influenza A H1N1, H3N2 and influenza B strains will be circulating during the next flu season. Usually the guess is correct, although sometimes it misses. In any event, global surveillance of circulating virus…