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Wednesday, August 29, 2018

Trying to solve Lyme Disease puzzle

Lyme Disease, Climate Change, and Science (or the Lack of It)
By David Scales

Related imageThe increasingly bitter debate over Lyme disease is something like the partisan divide in American politics — “characterized less by warring sides than by parallel universes,” as Mary Beth Pfeiffer observes in her new book “Lyme: The First Epidemic of Climate Change.”

In one universe, she writes, are traditional infectious-disease physicians, who see Lyme as a bacterial nuisance but not a crisis — often relatively easy to diagnose and even easier to treat with a few weeks of antibiotics. It is seldom dangerous and very rarely deadly.

In the other universe are patients, many debilitated and suffering, who believe they are afflicted by “chronic Lyme," and their sympathetic doctors, who call themselves "Lyme literate."

These doctors diagnose the disease based on symptoms rather than blood tests, and are willing to treat patients with unorthodox antibiotic courses and other treatments — with little scientific evidence to support their use.

The situation cries out for a good book — an evidence-based deep dive by a serious journalist into this baffling tick-borne disease — and it would be gratifying to report that Pfeiffer had written it.

An investigative reporter for The Poughkeepsie Journal in the Hudson Valley (an early epicenter of the Lyme epidemic), she has legitimate credentials and knows her way around a medical study. As her subtitle shows, she takes mainstream science seriously.

Unfortunately, her book falls far short of its promise — ultimately widening the gap between the two universes she describes. Instead of a careful and equal weighing of evidence on both sides, she tendentiously reviews Lyme science in favor of the “literate” side, and too easily buys into the view that the scientific community is deliberately overlooking evidence it dislikes.
At her best, Pfeiffer uses flowing prose, vivid metaphors, harrowing stories of illness, and summaries of research to suggest that the seemingly inexorable rise of Lyme disease is a perfect storm of our own making.

We colonized forested areas; we protected deer and other wildlife essential to tick life cycles; and as summers grow longer and winters shorter thanks to human-caused global warming, we’ve increased the likelihood that suburban gardeners and hikers will be bitten by infected ticks.

Pfeiffer offers a detailed survey of current debates and promising animal and lab research on Lyme, like xenodiagnoses (testing ticks for the disease after they’ve had a chance to feed on animals with suspected infection) and prolonged immune responses to the remnants of destroyed bacteria.

But in a conceptual leap, she cites these studies as potential explanations for befuddling symptoms like chronic joint pain, brain fog, and fatigue, even though there is little clinical evidence in humans to support them. This sets a pattern of relying on descriptive narratives, anecdotes, and very early research to make factual claims that seem premature at best.

In a contested, controversial field, source transparency is paramount, but it took me much effort and persistence to distinguish between myth, perception, and fact in Pfeiffer’s book.

Trying to find supporting evidence for many of her assertions led me on frustrating trips through the 20-page references section without links between the text and a corresponding citation. This may be a persnickety critique, but it is a symptom of a significant problem: Pfeiffer repeatedly fails to remind readers what is opinion and what is fact.

Her assessment of the scientific evidence is often unbalanced. She dismisses randomized, double-blind, placebo-controlled clinical trials in humans — the highest-quality evidence we have — for minor flaws.

But she doesn’t turn that same critical eye on research reporting that, for example, bacterial persistence “potentially explains why many people stay sick even after they are treated.”

In a five-page section reviewing multiple studies and interviewing different researchers, she puts little emphasis on the crucial caveat that this persistence phenomenon has so far been observed only in lab and animal studies.

Pfeiffer also tends to blame scientific prejudice when the Lyme researchers she favors fail to receive grant funding or to get their work published in journals. This overlooks some crucial context:

While success rates for NIH grants vary, they tend to fall between 10 to 20 percent. If her assertions were true it would indeed be a disturbing trend, but considering many of the researchers she cites were recently awarded NIH grants, more evidence is needed before the reader can come to the same conclusion as the author.

These examples bring to light an illuminating juxtaposition in a book linking climate change and Lyme. For Pfeiffer, climate change is uncontroversial; yet she depicts Lyme science as shrouded in uncertainty and conspiracy.

Many of her insinuations sound eerily similar to the familiar aspersions cast by climate deniers against the overwhelming scientific consensus on climate change.

While the studies supporting Lyme guidelines are not as robust as climate science, an international consensus does exist for the diagnosis and treatment of Lyme disease, which advocates similar diagnostic protocols and standard antibiotic treatment courses.

The author reports on conflicts of interest by guideline writers of the Infectious Diseases Society of America (IDSA).

Even though a special review upheld the guidelines, Pfeiffer uses guilt by association to suggest that similar bodies in other countries cannot be trusted. (In fact, panels of scientists in Switzerland, Canada, and the United Kingdom have independently evaluated the evidence and published the same or very similar guidelines.)

Part of the confusion lies in Pfeiffer’s conflation of a threshold for scientific consensus with a threshold for medical treatment. There is a lot of subjectivity in weighing evidence, and reasonable scientists can disagree.

But population-level recommendations require as much high-quality evidence as possible, favoring data from human trials over laboratory and animal studies to avoid the “medical whiplash” that comes of reversing established guidelines. In places where evidence is thin, recommendations from recognized experts fill the gaps.

And the science behind such guidelines is different from the case-by-case practice of medicine, which relies not just on studies but also on clinical judgment.

Pfeiffer characterizes Lyme treatment as cookbook medicine, the only recipe written by the IDSA.

But physicians and patients face myriad uncertainties about Lyme and many other diseases; ideally they decide together when to deviate from a guideline because of individual circumstances. Some people are more willing than others to take on the unknown risks of experimental treatments (hence the recent push for a federal “right to try” law).

Pfeiffer lauds physicians who use experimental treatments based on such early evidence — and they may yet prove to be pioneers. But the evidence required for scientific consensus is much more stringent than what patients might need to feel comfortable in undergoing treatment themselves.

If you have diabetes, no one can stop you from treatment based on your faith in an in-vitro study of essential oils. But few scientists will agree to update clinical guidelines for your preferred treatment without higher-quality evidence.

In addition, “Lyme literate” physicians who advocate massive antibiotic interventions are flying in the face of efforts to conserve antibiotics, a limited resource in an age of rising resistance.

As part of Pfeiffer’s lament that Lyme patients struggle to receive prescriptions for nonstandard antibiotic use, she paints these doctors as victims of overreaching government regulators. But how to distribute limited resources is a policy question on which reasonable people can disagree.

Treatment guidelines change slowly — often much too slowly for suffering patients. Calling for more rapid action in the face of a perceived crisis is laudable (think of ACT UP’s AIDS activism in the 1980s and 1990s), but as critics of the “right to try” bill argue, the rush for access to nonstandard treatments can also put patients at risk.

Instead, the book might have paid more attention to groups trying to bridge the divide by focusing on improving symptoms for suffering, debilitated patients, regardless of the cause of their illness.

An excerpt from “Lyme: The First Epidemic of Climate Change” has been shared tens of thousands of times on Facebook, and the disease is getting more and more coverage from the likes of Vox and The New York Times.

Sadly, such coverage is all too likely to overlook crucial questions of bias and evidence quality. With lively narratives and clear heroes and victims, Pfeiffer’s book is likely to become a totem — but to one side only. We should all be worried when scientific uncertainty is adjudicated via clicks and shares.

David Scales (@davidascales) is an internal medicine physician at New York Presbyterian and an assistant professor at Weill Cornell Medical College.

This article was originally published on Undark. Read the original article.