Appropriateness of
Lyme Disease testing: an appropriate analysis?
by Raphael B. Stricker,
MD
California Pacific Medical Center
San Francisco, CA
4 August 2004
The article by Ramsey
et al. (1) concludes that inappropriate Lyme disease serologic testing is
common in Wisconsin. We believe that this conclusion is inappropriate.
Lyme disease is a controversial
illness (2–5). The controversy stems from the fact that the medical
literature focuses on the limited early symptoms of the disease, such as
the “bull’s-eye” rash and joint swelling, while ignoring
the serious sequelae of chronic Lyme disease such as neurocognitive dysfunction,
fibromyalgia-like pain syndromes and chronic fatigue (2–5). These symptoms
appear to be caused by persistent infection with the spirochete Borrelia
burgdorferi and/or coinfecting organisms such as Babesia, Anaplasma, Ehrlichia
and Bartonella (3–5). Chronic Lyme disease often occurs because of
the missed diagnosis and/or inadequate treatment of early B. burgdorferi
infection. The Centers for Disease Control and Prevention (CDC) estimate
that Lyme disease is underdiagnosed by a factor of at least ten, and serologic
tests for the disease remain flawed (3–5).
With this background,
Ramsey et al. commit two major errors in their analysis. First, they use
a very narrow definition of Lyme disease symptomatology to define “appropriate”
indications for testing while ignoring the protean features of tickborne
illness outlined above. This narrow definition of appropriateness guarantees
that valid screening tests would be labelled as inappropriate. Conversely,
truly “inappropriate” testing would only be performed on asymptomatic
patients; however, the authors’ narrow symptom definition makes one
suspect that “asymptomatic” patients did in fact have symptoms
of chronic Lyme disease, but that these symptoms were either not recognized
or not acknowledged by the authors. This probability is underscored by the
fact that emergency physicians had the highest rate of ordering “inappropriate”
Lyme tests. If patients were indeed “asymptomatic”, why were they
being evaluated in an emergency setting? Thus the outcome measures in the
article are suspect and suggest that the data is flawed.
The second major error
by Ramsey et al. is based on their apparent view that Lyme disease is a
trivial illness that is “hard to catch and easy to cure.” Thus
an “inappropriate” testing rate of 27% would be unacceptable for
this benign disease. If one compares the prevalence of Lyme disease with
that of other infectious diseases such as syphilis or AIDS, however, the
rate of “inappropriate” testing for Lyme disease (even by the
authors’ inaccurate standards) is relatively low. For example, the
yield from voluntary screening for HIV disease is generally about 2–5%
(6), while the yield from screening for syphilis may be less than 0.004%,
as shown in an article from the same issue of the Annals of Family Medicine
(7). Thus it appears that 95% or more of serologic testing for these diseases
may be “inappropriate”, but (the argument goes) since syphilis
and AIDS are such devastating communicable illnesses, the “inappropriate”
screening is justified. If one recognizes that chronic Lyme disease is also
a serious illness that may be difficult to diagnose and treat, an “inappropriate”
testing rate of only 27% seems equally justified.
Family practitioners
are often the first medical professionals to encounter a patient with Lyme
disease and to be faced with the challenging symptomatology of untreated
or under-treated victims of this illness. Consequently we feel that it is
especially important for your readers to have a better understanding of
Lyme disease and tickborne coinfections. We encourage family practitioners
to examine the evidence-based guidelines for the management of Lyme disease
recently published by the International Lyme and Associated Diseases Society
(ILADS) (8). Then test your patients in an appropriate manner.
References
- Ramsey AH, Belongia
EA, Chyou PH, Davis JP. Appropriateness of Lyme disease serologic testing.
Ann Fam Med 2004;2:341–4.
- Lautin A, McNeil
EL, Liegner KB, Stricker RB; Sigal LH. Lyme disease controversy: Use and
misuse of language. Ann Intern Med 2002;137:775–7.
- Stricker RB, Lautin
A. The Lyme Wars: time to listen. Expert Opin Investig Drugs 2003;12:1609–14.
- Phillips SE, Bransfield
R, Sherr VT, Brand S, Smith HA, Dickson K, Stricker RB. Evaluation of
antibiotic treatment in patients with persistent symptoms of Lyme disease:
An ILADS position paper. Accessed at http://www.ilads.org/ on August 1,
2004.
- Harvey WT, Salvato
P. ’Lyme disease’: ancient engine of an unrecognized borreliosis
pandemic? Med Hypotheses 2003;60:742–59.
- Centers for Disease
Control and Prevention (CDC). Voluntary HIV testing as part of routine
medical care—Massachusetts, 2002. MMWR Morb Mortal Wkly Rep 2004;53:523–6.
- U.S. Preventive
Services Task Force. Screening for syphilis infection: Recommendation
statement. Ann Fam Med 2004;2:362–5.
- The ILADS Working
Group. Evidence-based guidelines for the management of Lyme disease. Expert
Rev Anti-Infect Ther 2004;2(Suppl):S1–S13.
Competing interests:
None declared
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