How not to think

Thankfully, I don't receive all that much blog-related mail. But this weekend I received several communications about a piece in popular liberal blog. The piece is (ostensibly) about Lyme disease, which coincidentally happens to be one of the topics of my first post here at SBM. In fact, I've written about Lyme disease a number of times, and Dr. Novella has a very good summary of the controversy at one of his other blogs. Since we've discussed this so many times, I won't be reviewing the entire controversy, but looking at this particular blog post to examine how our personal experiences and errors in reasoning can distort our view of reality.

The topic of Lyme disease has come up recently in the press, and as the weather improves, cases in the northeastern U.S. should start to increase soon. Just as a reminder, so-called "chronic" Lyme disease is not Lyme disease at all. Lyme disease can have early and late manifestations, none of which correspond to the vague, protean symptoms labeled as "chronic" by some. The disease is often diagnosed without resort to objective evidence, such as reliable, positive lab tests. But let's look at the blog post in question and see what's there.

It sounds as if the writer of this piece has dealt with some terrible suffering, but the explanation she has reached for it is rather odd:

I came by my own ringside seat at these festivities courtesy of a tick bite incurred, probably on a hiking trail somewhere in the Sierra, in the late summer of 1984. I don't remember the bite. I never saw the tell-tale bulls-eye rash (I'm a country kid -- I got bit all the time by one noxious thing or another) that one of the warring camps insists must be present for a Lyme diagnosis to be accurate. But I do know that I went to bed one day in October of that year, and was never the same afterward -- and that I've been struggling with devastating bouts of exhaustion, body pain, and brain fog ever since.

The narrative sets up a chain of events, then looks for cause. The chain is "went for a hike" then "felt bad since". As we know, it is tempting to employ post hoc ergo propter hoc thinking here, but is it correct to do so?

There are several problems with this compelling and well-written narrative. First is the tick bite that wasn't. In medicine, we don't assume an event has happened unless there is evidence for it. If you have clear evidence for a tick-borne disease but don't remember a tick bite, then logic would dictate you simply had a bite but were unaware of it. If you hang your diagnosis on a tick bite, but don't recall the bite, then your reasoning is circular and nonsensical. "I have Lyme disease because I had a tick bite, and I know I got bit because of have Lyme disease" is a problematic statement.

Then is the misunderstanding of medical knowledge. Doctors do not insist on the presence of the erythema migrans rash in order to diagnose Lyme disease. It is a useful clue, but it's presence is not required. The writer's terrible understanding of medicine and biology truly blossoms later in the story. (By the way, "brain fog" is a common phrase in the literature of "alternative" diagnoses. There is no consistent definition, and it is not clear what the phrase represents.)

Over the years, various doctors pinned assorted diagnoses on these symptoms, all of which promised exactly zero hope for a cure.

[...]

But it wasn't until a year ago this past week -- nearly 24 years and a dozen or so doctors after my first collapse -- that I finally got a firm diagnosis of Lyme disease. Last August, after returning home from the convention in Denver, I started the difficult and demanding high-dose multi-layered antibiotic treatment. The average case of chronic Lyme takes two to five years of treatment to cure. At this late date, though, the odds are only about 70% that I'll ever be able to shake it. Still, six months in, my joints work again. I can exercise and travel without having to pay it back with weeks in bed. And my mind grows sharper by the day. The drugs are working -- and every day I'm better is a day of grace I never thought I'd see.(All emphasis mine. --PalMD)

There are some interesting bits here. First is the "zero hope for a cure." No one likes having there hope taken away. When we tell a patient that we don't know what's wrong with them this can be very unsettling. Of course, even when we don't have a precise diagnosis, we can still tell patients we will do everything we can to help them feel better. But some people want to hear an exact diagnosis and a clear plan for a cure---this isn't always possible. One approach to this uncertainty is to work closely with the patient to help ameliorate their symptoms. Another is to lie to them. I find the latter choice to be the easier one, but also the immoral and ultimately unhelpful choice. Now, let's see how quickly the writer can fail biology.

The treatment takes so long because Lyme is the most cunningly persistent bacterium known to science. In its native state, it's a spirochete -- a cousin to syphilis. But if you hit it with penicillin, it will convert in a matter of minutes into an intracellular form that's more like a mycoplasma, which will only respond to a macrolide antibiotic like azithromiycin or Biaxin. Or, just for fun, it will roll up into a hard cyst form that can hide, dormant, in the macrophages of cells, and then emerge to re-infect the host years on down the road. This well-armored third form responds -- only very reluctantly -- to Flagyl and a couple of the TB drugs. Curing the disease means taking large doses of several classes of antibiotics together for months at a time -- either orally, or through an IV -- so the germ will have nowhere to hide. And all the while, we also need to be carefully watching for and mitigating the drugs' own very real consequences to the body.

I'm not sure what it means that Borrelia is "the most cunningly persistent bacterium known to science." I mean, I have opinions I suppose. Mycobacterium tb is a clever fellow, as is syphilis. I'm not sure what makes Borrelia the most anything. A micro-organism can be the most prevalent, or the smallest or largest, but it can't be the most cunning. "Persistent" is an interesting one. I'm not sure what makes her think it's particularly persistent. Tuberculosis is very persistent, as are many of the human herpes viruses. As to the different supposed phases of the bacterium, it is not an obligate intracellular organism, and it is in fact not clear if it even can perisist within cells. As far as antibiotic sensitivity, I am not aware that this changes, although some antibiotics are better at different stages of disease. What is very clear from randomized controlled trials is that: 1) the somatic symptoms described by those with "chronic Lyme disease" are no more frequent in people who have had Lyme disease than in matched controls; 2) randomized controlled trials have failed to show any efficacy to prolonged antibiotic treatment in those who are described as having "chronic Lyme disease". The only source I could find that describes this particular "life cycle" of the spirochete is in the quack journal Medical Hypotheses.

To complicate matters further, the ticks that deliver Lyme usually deliver other diseases, too: babesiosis (a form of malaria), ehrlichiosis, mycoplasma, and others that also must be found and treated for a full cure to happen. Though these are nominally "deer ticks," entomologists have found Lyme-bearing ticks on birds, dogs, rodents, horses, and many other animals. Last week's chimp attack is also being blamed on a form of Lyme psychosis. It's probably true that veterinarians have a better handle on this disease than the doctors who treat humans do.

Ugh. I don't think she's ever taken a biology course. Babesiosis is not a form or malaria. Also, I don't doubt that veterinarians have a handle on animal diseases---I do doubt that they have a better handle on human disease. It's just not their thing.

I'm loathe to continue the line-by-line analysis of the piece, as I don't want to lose you here, so stick with me as I wrap this up. The article continues the pattern of conclusion--->evidence. Whatever the author may wish, we cannot do science by forming conclusions and then twisting the facts to fit these conclusions. For example:

However, once some strains of Lyme get dispersed and embedded in the body's tissues, the standard treatment won't touch them. Worse: the standard Lyme tests won't, either, so the results will likely come back negative. The shady politics of how the approved Lyme tests were developed would take a whole separate post to explain; but suffice to say that they're only 70% accurate on their best day, which would make them patently unacceptable as a diagnostic tool were it any other disease. Far more accurate and sensitive tests are available, but insurance companies won't cover the $400 fee.

These alternative Lyme tests are usually not covered because the are inaccurate. The chronic Lyme advocates have sought out shaky labs that will give them the results that they desire, rather than the ones with most accurately reveal the biologic facts. This leads directly into the Connecticut debacle.

Last year, the Connecticut attorney general actually harassed the Infectious Disease Society of America over their official treatment recommendations for Lyme disease. In a classic, but strangely backward Pharma shill gambit, the ISDA was accused of being in cahoots with various forces to deny proper treatment to people with Lyme disease. Part of the idiocy is that it is the chronic Lyme advocates who make millions administering expensive and disproved treatments. The ISDA guidelines are both evidence based and cost-effective.

This particular piece, posted on a popular blog, is a horrible piece of medical writing, but a perfect example of what can go wrong when a reporter doesn't understand science. The diagnosis and treatment of disease is supposed to be based on science, not on wish-fulfillment. It's difficult to have unexplained symptoms, but giving them a false label and subjecting oneself to fake treatments helps no one except the person receiving the check.