bird flu
revere | November 10, 2006Someone should tell the US government: "Big Blogger is Watching You." Both CIDRAP and crof's blog H5N1 picked up a story that the US State Department was advising its diplomatic and consular personnel in in Hong Kong and Macao to prepare for a possible "shelter-in-place" event by laying in a stockpile of food and water to last twelve weeks if there were a complete infrastructure breakdown in an influenza pandemic. CIDRAP noted this differs from advice on the US government pandemic flu site which suggests only a two week buffer.
You can read the original twelve week recommendation thanks to…
revere | November 8, 2006The headlines are exciting: Chinese scientists identify deadly gene in H5N1. The story is also upbeat:
Chinese scientists have identified a gene in the H5N1 bird flu virus which they say is responsible for its virulence in poultry, opening the way for new vaccines.
[snip]
"We can now understand how this virus becomes lethal and the molecular basis for its pathogenicity," Bu Zhigao at the Harbin Veterinary Research Institute told Reuters.
The science also turns out to be interesting, but on its face not the breakthrough the story implies. Maybe as we learn more we will find it is the key to…
revere | November 7, 2006Nothing says more about the routinely nasty depths American politics than this story.
In Houston, the city health department got money from the Robert Wood Johnson and Amerigroup Foundations, two charities much involved in health care, to provide free flu shots near polling places in medically underserved areas. This isn't uncommon. Some twenty other cities, in several states, are said to have similar "vote and vaccinate" programs (see for example, here). The idea is to go where the people who need the services are.
Nothing is simple anymore. Not even free flu shots for the poor. The right…
revere | November 6, 2006H5N1 bird flu is now in 55 countries, in each of which it has severe economic consequences on the poultry industry and carries with it an unknown but potentially catastrophic public health threat. Since it is s a disease of animals (primarily birds), much of the work has been done by veterinarians and ornithologists. One would expect us to have a great deal of information, given the attention this nasty virus has received, in the laboratory, the field and among the general public and press.
And we do. But a recent paper in the journal BioScience (published by the American Institute of…
revere | November 6, 2006Currently estimated bird flu case fatality ratio remains catastrophically high, somewhere around 60%. This may or may not be an accurate estimate. Case fatality is the ratio of cases that die to the number of people diagnosed with H5N1 infection. If we are missing many cases then our estimates of case fatality will be biased upwards. On the other hand, it is possible we are missing many deaths from H5N1 for the same reason: the case was not diagnosed. In Indonesia, for example, there are hundreds of thousands of deaths yearly from severe pneumonia. While the overwhelming majority are not bird…
revere | November 5, 2006Genes and bird flu are being talked about again. A WHO study is "stating" some kind of genetic factor may be at work, but it appears it is only an observation that in the notorious Indonesian Karo cluster of eight family members, only those "related by blood" were affected by the human-to-human spread:
Only blood relatives were infected in the Karo district of North Sumatra, the largest cluster known to date worldwide, "despite multiple opportunities for the virus to spread to spouses or into the general community," it added.
The theory - which it said merited further study - was contained in…
revere | November 3, 2006It is tiresome to report the same story over and over again (for a few previous posts see here, here, here, here and here), but sometimes necessary. It has been widely reported -- again -- that the Chinese Ministry of Agriculture is withholding isolates of H5N1 it promised to provide. Indeed, WHO's Beijing office reports it has received no isolates since 2004.
The issue came to the scientific world's attention again last week when a team of Hong Kong and American researchers reported a new sublineage of H5N1 has become dominant in southern China and southeast asia in the last year, the first…
revere | November 2, 2006[This is the last post in a series about viral and cell surface glycoproteins and their role in the influenza story. It's a slightly updated series from the archives on the old site. Links to all four posts: part I, part II, part III, part IV]
In the first three posts of this series we have given an overview of what the cell surface looks like to the influenza virus and set out the ideas and vocabulary virologists use to discuss the sugar molecules on the cell's surface the virus hooks on to, the viral receptor. The many possible configurations of sugars on a cell's surface serve important…
revere | November 1, 2006The Chinese news agency Xinhua reported last week that scientists at the Wuhan Institute of Virology found H5N1 in the feces of sparrow, non-migratory urban birds two years ago (via Reuters). The brief news report only says the discovery followed an outbreak among poultry in nearby Henan province. It's not clear what took so long to report this or whether the H5N1 strain in sparrows differs from that in poultry.
Is this good or bad for public health?
It's hard to think of ways it could be good for public health to have another endemic source of a virus potentially capable of infecting humans…
revere | November 1, 2006[This is the third in a reprise from the archives about some of the science of the influenza virus. Links to all four posts: part I, part II, part III, part IV]
An influenza virus does only one thing: tries to make many copies of itself. And it does it poorly, although prolifically. Instead of making exact copies it is liable to make inexact copies and this is one of the sources of genetic variation which produces the parallel "random experiments" characteristic of viral replication. Lots of the copies it makes are fine, but many are fatally flawed, and also many that are more or less…
revere | October 31, 2006Another vaccine "story" makes the wires, this time from Dynavax, a Berkeley biotech company. The story is pretty typical of the genre:
Drug companies typically design their seasonal flu vaccines to generate antibodies that neutralize two proteins, hemagglutinin and neuraminidase, on flu viruses. But because these two proteins are prone to mutate, new vaccines tailored to their changing characteristics usually have to be made every year.
That variability could prove devastating if the bird-flu virus suddenly mutates into a form that spreads quickly among people instead of just birds. By the…
revere | October 31, 2006[This is the second installment from the archives of a series of posts giving some scientific background on the influenza virus, in this case the terminology basics on viral receptors. Technical but not beyond the range of most well educated readers. Links to all four posts: part I, part II, part III, part IV]
In the last post we discussed the dense canopy of sugars linked to cell surface proteins that covers most cells. This outer fur-like sugar surface is called the glycocalyx and plays an important biological role, including cell-cell recognition and communication, interacting with and…
revere | October 30, 2006It sounds reasonable at first. If hospitals and clinics are going to be overwhelmed in a flu pandemic, prepare to care for sick family members at home.
But what if there's no one to care for you at home? That's the position of the one in four Americans who live alone. Even for those that have others to care for them there are serious barriers:
Almost half of those surveyed said they would run into financial problems or might run out of important drugs if health officials asked them to stay home for a week or more, said Robert Blendon, a Harvard School of Public Health policy expert who will…
revere | October 30, 2006[Back in January we did a series of posts on the old site giving some background science on the influenza virus for the general reader. The Reveres are traveling (for a change) and so we thought it was an appropriate time to dig around in the old archives and update some of the posts thought useful by readers. Here's the first installment of a set of posts on cell surface and HA protein of the influenza virus and where they fit in the picture. Links to all four posts: part I, part II, part III, part IV]
Avian influenza, as its name suggests, is a disease of birds. Most aquatic waterfowl…
revere | October 27, 2006A letter from Philip Mortimer of the UK's Health Protection Agency to the CDC journal, Emerging Infectious Diseases, calls attention to an apparent increased risk for death from influenza among a subpopulation, pregnant women. Mortimer alerts us to the fact that most (all?) national contingency plans for pandemics do not take this into account.
Mortimer cites literature from the 1918 pandemic that contains ominous figures:
Bland reported on pregnant influenza patients in Philadelphia and elsewhere in the fall of 1918; of 337, 155 died [Bland PB. Influenza in its relation to pregnancy and…
revere | October 24, 2006We're getting down to it. What's the scientific basis for a lot of advice that's being given out as if its uncontroversial. Like washing hands. Or shaking hands is the way flu viruses are passed around. From Helen Branswell's usual superior reporting:
Might we all be a little healthier this cold-and-flu season if we abandoned the handshake culture? With mounting concern about a possible influenza pandemic and growing awareness of the economic costs respiratory ailments exact through absenteeism, some people are wondering precisely that. (Branswell, Canadian Press)
Makes a lot of sense.
Those…
revere | October 24, 2006An urgent communication from the World Health Organization (WHO) expresses concisely how far behind we are in being prepared for a global pandemic of influenza. Currently there are a number of vaccines under development, some of which might protect against an H5N1 virus that has become readily transmissible from person to person. But none are in production, and even if some were found adequate (not the case) and large scale production begun (far from the case), we, the world, would still be in a fix:
"We are presently several billion doses short of the amount of pandemic influenza vaccine we…
revere | October 23, 2006Helen Branswell has a story about a battle being waged among virologists and occupational health specialists regarding how influenza is spread from person to person:
Later this week virologists, infection control specialists and occupational health experts from Canada, the U.S. and Britain will gather in Toronto to start trying to answer a question that is the source of a polarized debate among them.
How does influenza spread from one person to the next in hospitals? Is it mainly transmitted by hand-to-hand contact and virus-laced droplets sneezed or coughed from the respiratory tracts of the…
revere | October 20, 2006We've said it here often, but it's nice to see it in the commercial print media.
Less than a year ago, Americans could barely turn on the television, surf the Internet or pick up a newspaper without finding a doomsday story about deadly avian flu.
By last November, President Bush had asked Congress for $7.1 billion to help develop a vaccine, stockpile antiviral medications and fund state preparations for a possible pandemic.
Now, with the disease still centered in Asia and the failure of migratory birds to spread the illness to Europe and North America, the H5N1 virus has dropped out of the…
revere | October 19, 2006There's a report on the wires that scientists at the Vaccine Research Center (VRC) at U.S. National Institute of Allergy and Infectious Diseases have developed a DNA vaccine that protects mice against the reconstructed 1918 virus. The paper just appeared online in the Proceedings of the National Academy of Sciences (PNAS, also known as "penis" in the trade). At this point the paper is more important for what it reveals about how the mouse immune system protects against this notorious virus than as a demonstration of a vaccine technology for use in people. That is much further down the road.…