infectious disease
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…
tsmith | October 22, 2009I've written previously about "chicken pox parties". These types of events are coming back into vogue (they were common in the days before the vaccine, when the only way to provide immunity was to be infected), as parents mistakenly believe that "natural exposures" to these pathogens are somehow superior--and safer--than vaccinations. Though the latest rage are "H1N1 parties", chicken pox parties are still around, and potentially being held at your local McDonald's by families connecting on the internet:
I am trying to put together a chicken pox party and am looking for someone to donate…
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…
tsmith | October 21, 2009I realize that, despite the scientific evidence to the contrary, there is still a lot of fear and misunderstanding about vaccine safety. Two recent articles discuss this "epidemic of fear" and why it affects us all, the first here at Wired magazine, and the second here at the Gotham Skeptic. I especially like the second, which has some excellent points:
My pediatric practice is situated at the nexus of three Manhattan neighborhoods (the West Village, Chelsea, and the Meat Packing District) that seem to comprise just the right balance of wealth, edginess, and socio-cultural awareness that…
revere | October 20, 2009When swine flu appeared, the pork producers were keen to say there was no connection or relationship between pigs and swine flu (even though the virus's genetic segments were all of swine origin). They didn't want anyone to call it swine flu, giving rise to the celebrated naming controversy. But then we started seeing pigs infected with human pandemic swine flu, both in the lab and in pig herds. It's likely the pigs got it from us, although which direction things went in isn't completely clear. But originally the virus made the jump from pigs to humans, probably sometime in late 2008 or…
revere | October 18, 2009We've been traveling again (and offline), so we'll limit this to a few comments to put recent news into the context of things we talked about here recently (an excellent up-to-date status report can be found by DemFromCT at DailyKos). A good article by Rob Stein of the Washington Post highlighted some of the increasing anxiety of clinicians as flu season ramps up with pandemic swine flu in the northern hemisphere. Stein's article is quite long, but I have snipped a few things from it:
Although why a minority of patients become so sick remains a mystery, new research indicates that H1N1 is…
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 27, 2009Flu season has started in earnest, even though it's not "officially" flu season until week 40 (first week in October this year). How do we know it's flu season if we don't test everyone and can't count flu? We use a surveillance system. The flu surveillance system has lots of moving parts and five or six components (or as many as nine, depending on how you count). None of them tell us exactly what we want and putting the different pieces together can sometimes be like the blind men and the elephant. But the system does work better than you'd think and it's undergoing modifications and…
revere | September 24, 2009Bats are no doubt fascinating animals. They also carry rabies. And I'll be honest with you. Rabies scares the crap out of me. Most people know that rabies is caused by a virus that is spread through the saliva of an infected animal. Because the virus attacks the nervous system, rabid animals often act aggressively and may bite, thus transmitting the disease. Fortunately vaccination against rabies is available and since the disease has a longish incubation period, there is usually ample time after being bitten by a known or suspected rabid animal to get a series of shots that will protect you…
tsmith | September 18, 2009Taking a brief hiatus from my hiatus to discuss a question I've been asked a number of times in recent weeks by friends and family: what about flu shots? Are you getting one for yourself? Your kids? The answer is yes to both, with more explanation after the jump.
First, for readers unfamiliar with this blog, let me be frank regarding my opinion on vaccine "controversies," such as "vaccines cause autism." As I've discussed here several times already (and more can be found by searching my older posts), this assertion is completely unsupported by many scientific studies, so this is not a…
revere | September 18, 2009Most people are either indifferent to swine flu or fearful, but the makers of Purell hand sanitizer and Chlorox are happy. It's been a boon to the business of sanitizing everything in sight as a way to ward off swine flu. Here's a story about Chlorox (bleach):
The company has secured additional suppliers and will increase production if needed, says Benno Dorer, senior vice president- general manager of Clorox’s cleaning division. Some retailers have already asked for more bleach, he said in a Sept. 4 telephone interview, declining to name specific companies.
An outbreak of the flu may add 2…
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 13, 2009At the beginning of September CDC initiated a new system for monitoring influenza activity. We reported last week that the old system ended on August 30 and that we were now into the new flu season. We even titled the post, "End of Flu Season." To paraphrase Mark Twain, the reports of the death of the 2008 - 2009 season may have been exaggerated. Well, not really, but the advent of the new system caused some confusion, at least for us, and we think we should clear it up.
There are several interconnected issues here. One is that the way trends in influenza will be monitored has been changed…
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 3, 2009When I tell people I am an epidemiologist, most of them think it means I'm a skin doctor. I'm not (although the skin disease specialty is much more lucrative). Instead I study patterns of disease in populations and use what I see to try to figure out why the observed pattern rather than another. Since I'm a cancer epidemiologist I usually do large, highly systematic studies that often take years to execute and analyze, but some epidemiologists do much more immediate "shoe leather" epidemiology, investigating disease outbreaks. They are like disease detectives and we can often learn a…
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…