Influenza treatment
revere | October 23, 2009While we don't yet know with certainty the relative contributions of the three most likely modes of transmission for influenza (large droplets, small aerosols of viral laden material that remain suspended in the air for hours or days, inanimate objects like door knobs or desk tops), it is certain that if you are in the path of a cough or sneeze or even vigorous talking from someone actively shedding flu virus you are at risk. When it comes to delivering big time viral loads, nothing quite beats a vigorous cough or sneeze.
Take a look:
Of course it may not be so easy to "just stay home." The…
revere | October 22, 2009A reader (h/t MVD) sent me this link to a "CBS News Exclusive," Study Of State Results Finds H1N1 Not As Prevalent As Feared. As far as I can see the main aim was to raise CBS News's profile and gain readership. That's what news organizations do. We hope they do it by good journalism. I think this is an example where the reporters just didn't have enough knowledge of what they were reporting and put the wrong spin on it.
The central claim is that CDC stopped testing for swine flu hastily and without advance notice to the states:
If you've been diagnosed "probable" or "presumed" 2009 H1N1 or…
revere | October 21, 2009We've gotten the question here fairly frequently: If antivirals (Tamiflu, Relenza) for swine flu work best when given early but shouldn't be given to people who aren't really that sick, how do you balance waiting for them to get sick and have the drugs not work well with giving it when you don't need to? There is no absolutely right answer to this difficult question. Early in the pandemic antivirals were being given prophylactically to stop spread, then they were being given only when a diagnosis of swine flu was confirmed. Then only to the sickest patients. We're all on a learning curve. The…
revere | October 13, 2009The online publication of three papers and a commentary yesterday in the Journal of the American Medical Association (JAMA; free access, links at bottom of post) provides some further data on what demand for critical care resources might be from the current swine flu pandemic. One paper reports on the Mexican experience, where mortality seemed unusually high but where access to services may have made the outcome worse. The papers from Canada are perhaps most pertinent to what might be experienced in the US and Europe. It appears that in terms of demand for ICU beds, the first wave from last…
revere | October 10, 2009When swine flu poked its head above water in the northern hemisphere in April our "normal" flu season was just ending. A surge of swine flu cases during a time when influenza was not usually seen was bewildering and confusing, not to mention alarming. We didn't know what to expect nor were we sure if it would peter out over the summer, as flu usually seems to (we may learn differently in the future as we start to do surveillance over that period) and then come roaring back or just disappear. While it didn't peter out very much, the big question was going to happen when the northern…
revere | September 30, 2009For the first time in medical history we may be seeing an influenza pandemic unfold in real time, but that doesn't mean we know what we are seeing. There remains some uncertainty about virulence, both in terms of how often it kills and how it kills when it does kill. You'd think both would be easy to determine, but those who have been following along know the problem of how often infection with this virus kills is made almost impossible by not knowing how many people it is infecting. But what about the question of how it kills? There are mainly three scenarios of interest: primary viral…
revere | September 29, 2009Hand gel sanitizers are making an appearance all over our medical center. There's one right next to the elevator on the ground floor of the building where my office is and don't have to touch a thing. Just put your hand under it and it dispenses a cool alcohol-based gel that sanitizers my hands and dries very quickly. Alcohol does that. And other things:
Alcohol hand gel meant to combat swine flu has been banned from a prison after inmates started eating it and became embroiled in a drunken brawl.
Inmates have been drinking the liquid soap placed on their wing after realising it contained…
revere | September 17, 2009I just got my seasonal flu shot. It was free and my medical center is encouraging everyone to get one. I wouldn't be telling the truth if I said I didn't feel it at all, but in all honesty, I hardly felt it. They must be using smaller needles these days. Anyway, given that most circulating flu virus is pandemic swine flu H1N1, for which a vaccine is not yet available (coming soon to a clinic near you, we're told), you might wonder why I -- or anyone --would bother. I'll do my best to explain my reasoning, but I'll grant at the outset I may have missed some good reasons or have reasons that…
revere | September 16, 2009There is no way to keep up with all the flu news, so we pick and choose, usually based on some kind of point we want to make. That's both the good and the bad of this blog: the news comes with a point of view. But so does most news, and we try to make ours both explicit and scientifically as accurate as we can with the information at hand. Today is a typical example. Bloomberg is reporting that any swine flu virus resistant to oseltamivir (trade name Tamiflu), the only antiviral pill effective at all for the infection, transmits less well than swine flu that's sensitive to Tamiflu. The source…
revere | September 9, 2009One of the most feared outcomes of infection with influenza is Acute Respiratory Distress Syndrome (ARDS; in less severe form it mahy be called Acute Lung Injury, ALI). For reasons we still do not understand, cells deep in the lung that are involved in gas exchange (oxygen and carbon dioxide) become so damaged that the basic work of supplying the body with enough oxygen for life and getting rid of the carbon dioxide generated by metabolism is too much for the patient and either some intervention to relieve the lungs of some of the work is made or the patient dies. ARDS is so severe that often…
revere | September 8, 2009As we expected, yesterday's vaccine piece provoked a lot of discussion, almost all of it thoughtful and pertinent. Since we've already said we might be wrong, we thought we'd take some time to respond, using it as a way to keep thinking things through on our end. Writing is thinking and thinking is needed in this situation.
Over at FluTrackers.com (an excellent flu forum like Flu Wiki with highly informed people) there were a number of lengthy responses, most of them on the negative side. Since these folks follow events closely their opinions are also worth following closely. In addressing…
revere | September 7, 2009When it comes to US swine flu vaccine policy, I'm not calling the shots, but if I were I'd do it differently than the current plan, which calls for a vaccine containing only viral antigen and no immunity boosting adjuvant. I opt for a vaccine with an adjuvant, probably the one that has been used for years in Europe, MF59. If I were to make a decision like that, I could well be making a mistake, because no one really can know at this point what is going to happen or not happen. We can only go on the best data we have coupled with some principles of what's right. On that basis and using my own…
revere | September 4, 2009A meeting of critical care specialists who have treated severely ill swine flu patients this week in Winnipeg, Canada is producing dramatic reports of illness with a virus more like H5N1 (avian or bird flu) than seasonal flu. Since H5N1 is dramatically more virulent than any seasonal flu we know of, including the 1918 H1N1 variant, this sounds alarming. Before we hit the panic button (and we should never hit the panic button, anyway), let's consider the larger context.
Everyone agrees that swine flu H1N1 is not seasonal flu. Its epidemiology is quite different and there is very little natural…
revere | September 2, 2009Yesterday one of the questions we asked was whether swine H1N1 would replace seasonal viruses this season. In previous pandemics one subtype completely replaced its seasonal predecessor: in 1957 H2N2 replaced the H1N1 that had been coming back annually at least since 1918; only 11 years later, in 1968, a pandemic with H3N2 replaced the H2N2. H2N2 is no longer circulating but in 1977 an H1N1 returned and has been co-circulating with H3N2 since then. This was a new situation. We could ask why this hadn't happened before with H2N2 and H1N1 or H2N2 and H3N2 or all three together; or we could ask…
revere | September 1, 2009It's not Labor Day yet, but I guess the Reveres have to consider their vacation over. We're all back at our respective home stations. We admit that not watching flu evolve daily was a relief, although we did sneak peeks when we weren't supposed to. But it also proved to be like the stock market. The daily ups and downs sometimes obscure the bigger picture. So what does it look like now?
We have two contradictory impressions. One is that the pandemic has continued to develop in a very robust fashion. So it's a dynamic picture of change. The second is that it looks like a normal pandemic, just…
revere | August 11, 2009Yesterday (today as I am writing this) the British Medical Journal published another Cochrane meta-analysis on the efficacy of neurimminidase inhibitor antivirals (the only two in use now, being oseltamivir [Tamiflu] and zanimivir [Relenza]). Their conclusions have made the news, so I guess I should cast my baleful eye on their handiwork. I think there is less here than meets the eye, but first let's look at what meets the eye.
This is a meta-analysis, that is, an analysis of other analyses, the other analyses in this case being drug trials of Tamiflu or Relanza in children. So it's an…
revere | August 5, 2009I have a reflexive skepticism about some conventional flu wisdom. There's so much about flu we don't know and even more we think we know that we find out we're wrong about. But skepticism is an occupational hazard of epidemiologists. Our training and practice focusses on detecting subtle biases that can produce misleading interpretations of data. When it comes to the commonly recommended personal protective measures for pandemic flu, our skepticism is all the greater since there is so little data to be skeptical about. The lack of data isn't an accident. If you think hard about it, you can…
revere | July 28, 2009CDC wants us to get vaccinated for flu every year. Always for seasonal flu, and this year, if there is a vaccine available, for swine flu. They want us to get vaccinated because they think the vaccine works and they want to prevent people from getting influenza, always a dangerous and unpredictable disease, even if most of us usually escape with just a flesh wound. CDC backs up its recommendations by a quite a few scientific studies demonstrating the vaccine is effective, citing figures that the vaccine is 58% effective or 91% or effective or some other number, depending on what group is…
revere | July 23, 2009There have been three reported oseltamivir (Tamiflu) resistant isolates of H1N1 swine flu (added: and now a fourth in Canada) but with those exceptions all others have been sensitive to this oral antiviral. This is in marked contrast to the other H1N1 strain, the seasonal variety which is almost entirely resistant. The spread of Tamiflu resistance in the seasonal strain happened with dramatic suddenness in the winter of 2007 - 2008 and came as an unhappy surprise. People assume that a rapidly mutating virus would inevitably become resistant, but based on several laboratory studies there were…
revere | July 15, 2009I hate to take off on the press. I do it every once in a while, but not often. The slow and agonizing demise of the main stream press has major consequences for keeping the public informed about issues both big and small. It's also a personal tragedy for many dedicated professional journalists. Still, while newspapers-as-we-knew-them aren't dead yet, they are at least moribund, and like the famous definition of a statesman as a successful politician who is dead, there is more than a bit of a tendency to endow the working press with some virtues it doesn't have now and in general never did.…