A recent story in The Free Lance–Star about a local woman who went for years with a debilitating illness that no one could diagnose—which turned out to be Lyme disease—obviously was food for thought for some readers.
I got an email from Penny A. Parrish asking why she can’t get an annual blood test “to see if the nasty little things have already done their deed.” That is, to see if she has been bitten by a tick and been infected with spirochete Borrelia burgdorferi, which causes Lyme disease.
The answer, and the whole business of Lyme disease, touches on some interesting medical issues, such as determining when a screening test is appropriate, and how to deal with a hard-to-diagnose illness. To help me, I spoke to Dr. Norman Bernstein, a Fredericksburg infectious disease specialist.
To Test or Not to Test
Deciding whether a test should be used as a routine screening tool depends on the quality of the test and the prevalence of the disease in the community.
Blood tests for Lyme disease are positive in only 29 percent to 40 percent of people in the first two weeks after they have been infected, which is when you really want to know, because that’s when treatment is pretty simple and effective.
The test also has a fairly high false positive rate. Certain autoimmune diseases and other infections, such as HIV, syphilis and mononucleosis, can cause the Lyme test to be positive.
Then, the prevalence of Lyme disease in Virginia is relatively low—even though it seems ticks are relentlessly marauding down from New England, where the disease was first identified in Lyme, Conn. So the Infectious Diseases Society of America does not recommend routine screening tests for Lyme.
If someone turns up with the typical bull’s-eye rash and has been bitten by a tick, you don’t bother with a blood test. A two-week course of an oral antibiotic, such as doxycycline, will usually fix it.
Making it harder is that Lyme is not like a urine infection or an abscess, where you can culture the organism to confirm the diagnosis. Nor does analyzing the tick help very much, as even if infected, it doesn’t mean it has transmitted the spirochete.
Apart from the blood test being a bit iffy, there are other features of Lyme disease that make it hard to manage.
There are several exotic-sounding diseases that ticks carry, such as babesiosis, ehrlichiosis, Rocky Mountain Spotted Fever, anaplasmosis, Southern tick-associated rash illness, tick-borne relapsing fever and tularemia, which sometimes can be confused with Lyme disease.
Another thing about Lyme disease is that it often presents with a whole slew of nonspecific symptoms. Rashes, joint pains, fatigue, tingling and rapid heart beat are all things caused by a lot of other illnesses.
So it is that people can go years with no one able to figure out what’s wrong.
Or, people are told they’re crazy. Polly Murray, the first person to be diagnosed with Lyme disease, was admitted to a psychiatric hospital for a while until it was found she had this previously undiscovered infection transmitted by ticks.
Mind, some people really do have a psychosomatic illness, or even more properly, Somatic Symptom Disorder. Here, people can have profound, disabling problems but no organic cause for it—a situation that causes no end of strife to both patient and doctor.
Then, there are persistent forms of Lyme. There is post-treatment Lyme disease, where it persists after treatment and usually requires a longer course of antibiotics. Some also claim there is chronic Lyme disease, where people who have not been shown to have Lyme have suggestive symptoms. This is an area of heated controversy between “nonbelievers” and “believers,” or “Lyme literate doctors,” as they seem to prefer to be called. (As I have said before, I always thought fairies and leprechauns are the kind of things you do or don’t “believe” in.)
The characteristics of Lyme disease and the test for it mean that routine testing is not a good idea. If you test someone with no symptoms of Lyme, there’s the quandary of deciding what to do with them and knowing whether the result is a true positive and should be treated, or a false positive.
Diagnosing and treating Lyme is a combination of clinical assessment and lab tests. It’s another example of the art of medicine, rather than pure science.
Dr. Patrick Neustatter of Caroline County is the author of “Managing Your Doctor: The Smart Patient’s Guide to Getting Effective Affordable Healthcare.”