bird flu
revere | November 9, 2007Influenza A/H5N1 (bird flu) bubbles away this year much as in past years and public health professionals continue to wait with bated breath for the other shoe to drop. It could happen this year, next year or not at all. That's the way the world is. Betting on "not at all" isn't considered prudent by most people in public health, despite the fact that it's possible. So given the uncertainty, what is the best strategy?
It is a bit disconcerting to see that the overwhelming preponderance of resources to pandemic preparedness resources are going into influenza-specific counter-measures,…
revere | November 8, 2007Via the Clinician's Biosecurity Network Report we learn of a new study from the Webster St. Jude laboratory in Memphis showing that H5N1 can mutate to oseltamivir (Tamiflu) resistance without any loss in genetic fitness. Tamiflu resistance has been seen but infrequent and there was considerable evidence that the resistant strains were handicapped in some way, thus making them either less virulent or less transmissible. The hope was this was a built-in limitation. Now we know it isn't:
To investigate the fitness (pathogenicity and replication efficiency) of NAI-resistant [neuraminidase…
revere | November 6, 2007When the emergency room gets a huge influx of cases in a disaster it's time for triage, the separation of the those most likely to need and benefit from immediate emergency care from those that can wait or can't be helped. In a mass casualty disaster the assumption is that triage should start outside the doors of the ER, sending only the sickest there. Makes sense. But is it true? A computer simulation done by Cornell Medical School suggests it might not be:
. . . researchers at NewYork-Presbyterian Hospital/Weill Cornell Medical Center have created a computer simulation model of trauma…
revere | November 5, 2007I don't like to be a curmudgeon and I'm pretty tolerant when students write research papers that don't quite make professional grade. Writing papers may look easy -- you just have to report your results, right? -- but it isn't. Nor is designing a study or collecting the data. It takes time and practice to learn this and you make a lot of mistakes. I know from personal experience. It's the job of mentors, advisors and journal editors to educate students, bring them along, show them how to do it.
Apparently none of these guardians of the literature were awake when the paper, "Medical students…
revere | October 29, 2007If you've heard of the disease distemper it may be because you had to get your dog vaccinated against it. Dog or canine distemper is caused by a measles-like virus, Canine Distemper Virus, but it doesn't just affect dogs. It is capable of jumping to other species and wiped out about 10% of the world's smallest seals, the Caspian seals. Other carnivores that have taken a big hit from CDV are the Tasmanian tiger and black-footed ferret. It can infect infect lions and hyenas and probably other animals in the wild. So the question of what enables the dog virus to jump to other species is not just…
revere | October 26, 2007Two months ago Germany reported H5N1 in asymptomatic ducks and geese.
Now the UN's Food and Agriculture Organization is saying this may be
a sign that there is already a reservoir of hidden infection in
healthy domestic birds in Europe. The FAO points to a huge popuation
of chicken and waterfowl in the Black Sea area that are similar to
asian bird populations and in contact with them via migration. FAO
wants more surveillance of domestic ducks and geese in some eastern
European countries that have not kept up as much as their western
European neighbors:
"It seems that a new chapter in the…
revere | October 25, 2007The "experts" have spoken to WHO and WHO has spoken to us: because of the march of science, there's been a large upswing in the estimates of how much vaccine the world could produce in a pandemic -- if such a vaccine existed and there was a way to deliver it. But if there was one and it could be delivered, then WHO thinks we could produce up to a 4.5 billion doses by 2010 as a result of new manufacturing technologies and techniques to make the produced antigen go farther. A lot of "ifs," to be sure, but without the ability to make the stuff the rest doesn't matter.
At the moment we make a…
revere | October 24, 2007There's a line forming for the pandemic vaccine that doesn't yet exist. Sort of like a new Harry Potter book except it's not first come first served. Like a sinking ship, it's (pregnant) women and children first -- or among the first. The deployed military? Police, I understand. But deployed military? They come ahead of critical infrastructure (power, water, communications) and older children? They come ahead of food and agricultural workers?
"Certain military personnel like deployed forces would get vaccinated before certain other military personnel," HHS science adviser William Raub said in…
revere | October 19, 2007The President vetoes health care for kids, the Congress almost overrides it but not quite, and the American Academy for Pediatrics says the next likely pandemic flu bug, influenza A/H5N1, targets children and is being overlooked as the country whistles past the pandemic graveyard:
"Right now, we are behind the curve in finding ways to limit the spread of a pandemic in children even though they are among the most at risk," said Dr. John Bradley of the American Academy of Pediatrics, which co-authored the report with the Trust for America's Health.
[snip]
Children have long seemed particularly…
revere | October 18, 2007Almost everyone now seems to think the Iraq debacle was, well, a debacle. Many of us thought invading Iraq was a terrible idea to begin with. Others are silent on that issue (or approved) but think it was carried out poorly. No planning. Failure to plan, however, is a hallmark of the Bush administration. Their intentions are pre-programmed but they never seem to plan for the consequences of those actions. It's not just Iraq. Or Katrina, for that matter. It's also pandemic flu:
When you ask federal officials around the country if they are prepared for a pandemic flu, the answers are unsettling…
revere | October 17, 2007In the first part of this two parter we summarized some biology background to a new paper that appeared online ahead of print in the FASEB Journal, Yuo et al., "Avian influenza receptor expression in H5N1-infected and noninfected human tissues." The paper addresses an important gap in our knowledge. Are there cells in the human body with appropriately matched receptors for avian flu virus and if so, where are they? Sporadic results in the last few years suggested that cells deep in the human lung (so-called type II pneumocytes) and ciliated cells in the upper respiratory tract might have…
revere | October 15, 2007The need for better information about the science of avian influenza is urgent. But science is a slow process, or at least slow relative to an urgent time scale, even in times of rapid advances in technology. Even so, while we are waiting for the other shoe to drop, we continue to learn and unlearn about the influenza virus. One major gap has been understanding where humans have cells with receptors for bird flu viruses. A new paper published online last week in The FASEB Journal is finally providing some information. As usual, it is both informative and confusing. To understand what it is…
revere | October 12, 2007Interesting paper from McAuley et al. (St. Jude's) on the PB1-F2 protein produced by an alternative reading frame on the PB1 gene of the influenza A virus. Most of you know that genes encode proteins via a three letter code. If you read the sequence of three letters by starting one letter earlier or later you will get a different sequence (e.g., ABCDEF is two three letter sequences ABC and DEF, but if you start a letter later you get BCD EF+whatever would have started the next three letter sequence originally). You have shifted the three letter frame for reading, hence the designation as an…
revere | October 10, 2007It's taken longer than many of us wanted, but some new data on host susceptibility is now coming in. The influenza research group at St. Jude's has just published a paper in CDC's journal, Emerging Infectious Diseases, verifying that common land based birds can be infected with highly pathogenic avian influenza virus H5N1. The St. Jude's group inoculated house sparrows, European starlings and pigeons with four strains of H5N1 that were isolated in 2004 - 2006.
Hi path H5N1 was first found in poultry in southern China in 1996. It is lethal to chickens and other poultry. Ducks are usually…
revere | October 6, 2007The headline was worrisome: "Bird flu becoming riskier for humans." The story was about a new paper in PLoS Pathogens from Kawaoka's lab that was said to identify "a specific change that could make bird flu grow in the upper respiratory tract of humans," according to the lab leader.
Birds usually have a body temperature of 41 degrees Celsius, and humans are 37 degrees Celsius. The human nose and throat, where flu viruses usually enter, is usually around 33 degrees Celsius.
"So usually the bird flu doesn't grow well in the nose or throat of humans," Kawaoka said. This particular mutation…
revere | October 4, 2007Swedish scientists are warning about Tamiflu in the environment because it passes through sewage treatment plants more or less unchanged. Readers of this blog may remember this coming up before when Andrew Singer and his colleagues in the UK published an article in Environmental Health Perspectives a year ago asking a logical question: what would happen in a pandemic if everyone started taking hoarded and stockpiled Tamiflu at once? Singer gave good reasons to think the active form of Tamiflu, oseltamivir carboxylate, would pass through the wastewater system. The Swedish study apparently…
revere | October 3, 2007The report of another bird flu death from Indonesia wouldn't seem to be "news." In a way, the fact it isn't "news" is news but we'll put that aside for the moment. Another thing about the story that isn't news is that the victim is a young person from the city of Jakarta, not a resident from a poor rural household living cheek by jowl with poultry:
The Health Ministry has confirmed that a West Jakarta shop attendant died of the bird flu Friday, increasing the country's human death toll from the virus to 86.
Ministry spokeswoman Lily Sulistyawati said test results for the latest bird flu…
revere | September 25, 2007Lots of stories on the wires (e.g., here) about a Nature Medicine paper describing a handheld microfluidic lab-on-a-chip to detect H5N1 inexpensively in less than 30 minutes. It was hard to understand what was involved from the news articles so I retrieved the paper (published online in advance of regular appearance in the journal hardcopy). It wasn't a particularly easy read, but here is what I was able to decipher.
This device makes use of microfluidics technologies, essentially an emerging set of techniques for manipulating very tiny volumes of material -- tiny as in millionths to…
revere | September 24, 2007The National Health Interview Survey (NHIS) is the major source of information about the health of noninstitutionalized Americans -- you and me and our neighbors. Data collection started in 1956 and consists of ongoing data collection and special studies on illness and disability and their trends. Data is done using a questionnaire given to a representative household probability sample of the US population. If you want the gory details you can find them here. A recent report, presented in the CDC Morbidity and Mortality Weekly Reports (MMWR) QuickStats format, gives the estimated percentage…
revere | September 21, 2007We've talked here fairly often (see, for example, here) that the way and how far influenza virus spreads isn't understood or known precisely. That seems to be a big surprise, not only to the public but to many in the public health community who should know better. That's why I was pleased to see that this dirty little secret is finding its way into the public press (hat tip from one of our many readers in Oz, RobT):
It was a simple question: how far could a virus spluttered out of someone's mouth travel?
When Professor Lidia Morawska went looking for an answer, she was staggered to find…