Effect Measure

Trying to understand the Norwegian swine flu mutations

Sat, 21 Nov 2009 06:03:38 -0500

The Norwegian Institute of Public Health is reporting sporadic occurrences of a mutation in a portion of the flu virus that is involved with the process by which it attaches to cells. I use the word "sporadic" because at this point there is no evidence that the cases where the genetic change has been found are epidemiologically linked. Therefore we don't see it spreading from person to person but rather arising in people after they have been infected. At least that's how it appears from reports, but we have only preliminary information at this point. According to WHO, the mutation has been seen before, again sporadically and as early as April, in Brazil, China, Japan, Mexico, Ukraine, and the US. Should we be worried about it?

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The uninsured and surviving an accident

Fri, 20 Nov 2009 06:04:51 -0500

Swine flu is a special danger to the young, but the biggest danger to the young is not an infectious disease but unintentional accidents. No matter what your age accident is among the top ten causes of death, but for those between the ages of 1 and 44 it is number one. Prevention oriented accident specialists are fond of saying that "accidents are no accidents," by which they mean that many accidental deaths are in some sense avoidable, not freakish twists of fortune. So wear your seat belts and don't go golfing in lightning storms. And while you're at it, have health insurance, since there is now new evidence that not having it makes it more likely you'll die if you do have an "accident."

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The rapid flu test and coin flips; more confusion

Thu, 19 Nov 2009 06:07:10 -0500

The Director of Loyola University Medical Center's clinical microbiology laboratory is reported as saying that rapid flu tests are a public health risk. Here's some of what he said and then my explanation as to why it is misleading or just plain wrong:

Rapid influenza diagnostic tests used in doctors' offices, hospitals and medical laboratories to detect H1N1 are virtually useless and could pose a significant danger to public health, according to a Loyola University Medical Center researcher.
"At Loyola, we determined four years ago that the rapid tests for influenza detected only 50 percent of the patients who were positive," said Paul Schreckenberger, Ph.D., director of Loyola's clinical microbiology laboratory. "I can flip a coin and get the same results as I could with those tests. So what's the value of the tests? I can flip a coin for free." (Medical-News)

We've discussed this before, but since the underlying concepts seem poorly understood (even by clinical laboratory directors), it's time to discuss it again.

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Hate crimes, risks and numbers

Wed, 18 Nov 2009 06:37:16 -0500

I have been away (again) and out of internet contact most of the day, dealing with an unhappy family event. So this post is short but illustrates an important point that comes up frequently in epidemiology: the difference between risks and absolute numbers. The illustration is not medical, but I think sharper because of it:

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Swine flu and bird flu and lessons learned and to be learned

Tue, 17 Nov 2009 06:38:09 -0500

The blogosphere (DemFromCT at DailyKos) and the main stream media (Alan Sipress at the Washington Post) brought us the two faces of the current flu pandemic. Like Janus, one took lessons from the present and past, the other looked worriedly to the future.

Dem's piece on flu at DailyKos (a regular feature of the world's biggest political blog) is superb. Most everyone who regularly reads about flu in the blogosphere (and it is a huge readership) knows that DemFromCT is the blog handle of an expert who has been writing about pandemic flu for years (as long or longer than we have and we are coming up on our 5th blogiversary), knows the landscape intimately from both the policy and scientific perspective, and is himself a practicing pediatric pulmonologist, so in his daily practice he is in the eye of the storm. With those qualifications you'd expert the best and that's what you get. His post on Sunday, "Lessons Learned from the Pandemic" hits every nail on the head, and there are a lot of nails. He extracts 7 lessons and you should read his post in its entirety, but I'll tease you with the first lesson:

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WHO, swine flu in the Ukraine and bin Laden's beard

Mon, 16 Nov 2009 06:23:26 -0500

We were asked repeatedly offline and in the comments for our views on what was or was not going on in the Ukraine, but we steadfastly declined to post on it. We didn't know any more than you can find out from news sources, so we had nothing to add in the way of hard information, We did know there was a WHO team on the ground and we thought it best to wait to find out more. We still don't know much, except that news reports are suggesting that the health care system in the Ukraine is a shambles and its likely the chaos and panic were self-inflicted more than virally inflicted. Mike Coston over at Avian Flu Diary has a great run down and we agree with the way he approached it -- gingerly, cautiously but with the right amount of anxiety that something could be happening but it was best to wait for information before hitting the alarm button (I didn't say panic button because it's never appropriate to hit the panic button).

Meanwhile, multiple stories out of the Ukraine were detailing disorganization, incompetence, politicization of the outbreak during a presidential campaign and much else. Few citizens believed what their leaders or government were saying, which is probably just as well because the messages were often contradictory and confused. The most recent version of this is from the New York Times:

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Swine flu conspiracy theories

Sun, 15 Nov 2009 13:15:23 -0500

Any article entitled "On swine-flu conspiracy theories" should have an automatic warning label, but the one noted below, in the Canadian newspaper The Globe and Mail is really terrific (h/t ML). Conspiracy theories are all over the internet and they even show up here in the comments from time to time, but I'm glad to say our readership is saner than some. Like scientific theories, conspiracy theories aren't hard to formulate (humans being an inventive and imaginative species), but like good science, conspiracies aren't so easy to implement. It's not that conspiracies don't exist, the philosopher of science Karl Popper observed in The Open Society and Its Enemies:

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Freethinker Sunday Sermonette: we imagine

Sun, 15 Nov 2009 06:49:29 -0500

You all know this song, but it is unusually affecting when sung by a child:

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The common cold and influenza

Sat, 14 Nov 2009 06:39:35 -0500

We've talked aplenty about how much we still need to understand about influenza. Not just its basic biology but its dynamics. How does it spread over space and time and how existing infection rates affect future infection rates and how each are related to the number of susceptibles in the population. It's even more than that. There are other viruses perhaps competing for or perhaps cooperating with the flu virus in its sole job, to make copies of itself, using the host's (i.e., our own) biological machinery. You can imagine a scenario whereby once a lot of cells are infected by one virus, monopolizing the protein and genetic replication machines of an infected cell, gives another virus a harder time getting a purchase. Maybe that's how an influenza strain becomes dominant in a flu season. It got there first or was more efficient. And now a new idea has been broached, still highly speculative but no less intriguing for all that: maybe one of the forms of the "common cold" is somehow protective against getting influenza. This was suggested last month in a short communication by researchers at the Swedish Institute for Infectious Disease Control to the periodical Eurosurveillance (hat tip Deborah MacKenzie, New Scientist):

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Confusion between H1N1 and swine flu

Fri, 13 Nov 2009 06:24:45 -0500

We're writing this at an altitude of 20,000 feet, being on the road again and except for a few minutes here or there, without access to the internet most of the day. This means a lot of comments will probably go unanswered, so we'll say what we usually do in circumstances like this: talk amongst yourselves. Lots of smart people read this blog. Help each other.

A quick look at today's flu news tells me that CDC has updated its estimates, using the methodology we discussed in a previous post. And a survey at Arizona State University (ASU) released Monday shows the expected: that opting to call swine flu "H1N1" instead of swine flu has done nothing but confuse people. Predictable. Mrs. R. works in a health department and one of her colleagues was heard to say you could get H1N1 over and over again. He was wrong if he meant the swine flu H1N1 but quite correct if he meant H1N1 in general, because H1N1 is one of the seasonal flu subtypes that's been around since 1977 (and prior to 1957) and its antigenic drift every couple of years is the reason we have to change strains in the seasonal flu vaccine periodically. The confusion between seasonal H1N1 and swine flu H1N1 was quite evident in the ASU poll:

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Swine flu and US sick leave policy: the company we keep

Thu, 12 Nov 2009 06:05:44 -0500

I don't know if the rest of the world laughs at the US, but I feel quite sure they at least shake their collective heads when they hear how we lack one of the most important non-pharmaceutical measures against pandemic flu: paid sick leave. Of course only those countries with a policy of paid sick leave would be shaking their heads. It turns out, though, that's just about everybody:

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Armistice Day, 2009: Bring 'em Home

Wed, 11 Nov 2009 06:55:48 -0500

This is an exact repeat of a post one year ago today. Except for this preamble about how disgusted we are that we have to repeat it:

The Reveres, November 11, 2009, year six of the War in Iraq and year eight of the War in Afghanistan

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Respiratory disease outbreaks in nursing homes

Tue, 10 Nov 2009 06:23:44 -0500

Nursing homes (Long Term Care Facilities, LTCFs) are a favorite hunting ground for respiratory viruses, including flu. They are open to the general community, where visitors and employees mingle freely with the residents. The residents are usually of an advanced age, have other sicknesses that make them vulnerable and often have less active immune defenses. So when the swine flu pandemic began at the end of April, the Public Health Laboratory at Ontario's Agency for Health Protection and Promotion ramped up their respiratory infection outbreak registration system with the prospect that LCTFs would be hard hit. We now know that swine flu acts like other pandemic flu viruses and preferentially targets the young. This doesn't necessarily mean the elderly are spared, however. It's just that they are expected to suffer proportionately less than seasonal flu, which ordinarily spares the young. What adds interest to the results of the LTCF surveillance between April 20 and June 12, 2009 (roughly the first 2 months of the swine flu pandemic) is that technology was deployed to identify most of the viral agents causing respiratory disease outbreaks in the Ontario LTCFs, not just swine flu or even influenza in general.

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Surgical masks versus respirators for flu protection

Mon, 09 Nov 2009 06:23:00 -0500

We only just got to the surgical/N95 mask article in the Journal of the American Medical Association (JAMA). We've been traveling and haven't been able to keep up with what others were saying, but we're sure it's been well covered by the usual suspects. So we'll just add our take here, for what it's worth.

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Acknowledging Obama's failures

Sun, 08 Nov 2009 13:17:56 -0500

It looks like there's going to be some kind of health care reform bill, but we're not celebrating. It's legislation that could have been important and meaningful and instead is a neutered industry-friendly cup of weak tea with a Draconian anti-choice amendment. That Obama would disappoint us is no surprise. We expected it and predicted it during the presidential campaign. And we said we'd complain. And we are. Expecting it, though, doesn't prevent us from being disappointed and angry he has turned out to be lousy on things that count. He's not George Bush, we'll give him that. But no President in history was as bad as George Bush, an outlier's outlier (not to mention just a plain liar). So not being as bad as Bush is a stupendously low bar to meet. That the Democrats would be crappy was also expected. The worst Democrat is still better than the best Republican, but again, who isn't? More to the point, the worst Democrats are also stupendously bad on their own. There are a lot of terrific Democrats, but they didn't prevail, although they could have if Obama had helped. He didn't.

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