Richard Krieger, MD, chairman of the Infection Control Committee at Chilton Medical Center, and infectious disease physician at ID care, discusses tests used to diagnose Lyme disease and the potential consequences of misdiagnosis.
Interview Transcript (slightly modified for readability)
“The specific tests that you look for to diagnose [Lyme disease] is, blood tests, and actually, it’s fairly well laid out. The first one is a serologic test where they will actually look for the antibodies for the Lyme infection. When you’re infected, not just with Lyme disease, but with anything, you produce antibodies against that particular infection and the antibodies are specific for that infection. In other words, antibodies for measles are not going to have anything to do with antibodies for Lyme disease. If we can pick up antibodies that are specific for Lyme disease [through blood tests], then it means that you have, at the very least, been exposed to that infection. That test is the one that we need to start with [and it’s] a sensitive test, so occasionally we’ll have somebody who tests positive that doesn’t have it, who really wasn’t infected with Lyme disease, they maybe had something else that made it look like it was Lyme disease.
They do something that they call a Western blot test which is, not to get too much into the technique of it, but it’s a more specific test [and] if that comes up positive then that’s a fair certainty that at [the] very least that person was exposed. Now the other side of that coin is, a positive test does not always prove that somebody has Lyme disease, it proves that they were infected at some point, but if somebody were infected say ten years ago, and maybe they got over it or maybe they got mildly ill and got over it, or whatever, the symptoms they’re having today may be from something else. It’s not like doing the test [and if] it’s positive, [we say] ‘You’ve got Lyme disease,’ it’s the other way around. If you have those symptoms and you do the test and they’re negative, the test is negative, then those symptoms are probably not Lyme disease.
The test doesn’t prove that those symptoms are due to Lyme disease. So again, if you have a positive test, and you have symptoms, if the symptoms are nonspecific, then, if possible, you have to delve in further with [patient] history, [asking questions] such as, ‘did you have the rash? Were there other symptoms previously that might have been more specific for Lyme disease, such as the rash, palpitations? Did you have a flu-like illness?’ Although everybody has one of those at one time or other so that’s kind of nonspecific in itself. ‘Tick exposure?’ Then, ultimately, [with] some people you can’t get any more specific than that and with somebody like that we often will treat them to see if they respond.
The trap that people fall into is they may treat them and they don’t respond, so they say, ‘Oh, it didn’t work. We treated you for four weeks, let’s treat you for four weeks more and for four weeks more.’ [Then,] you see people coming in who are getting treated for two years, three years at a time [and] some doctor is making a lot of money, some infusion company is making a lot of money, [and] the patient is just suffering because they’re getting treated for something that they never really had in the first place.
[In addition,] the treatment is not without side effects; drugs have side effects and I have seen at least two cases of people who were being treated for Lyme disease that they didn’t have who got very serious infections from the intravenous lines because they put an intravenous line in. Now, they put it in the arm; they used to put it [in the chest], but wherever they put it, if you have an intravenous line for a long period of time and use it every day (which is why you have it, the intention is to use it), every time you use it you run a small risk of infecting it, so no matter how scrupulously careful you are, it can get infected.
I saw one woman come in who was being treated, I think it was [for] about two years, for Lyme disease she didn’t have. She ended up getting bacterial meningitis with bacteria that almost never causes meningitis; it causes serious bloodstream infection and so, she didn’t have Lyme disease infecting her brain, she had this disease that came close to killing her. She took months and months to rehabilitate from the meningitis.
I saw another young woman who had a raging infection in her bloodstream with, I think it was four different bacteria, because she had an infected intravenous line that she never needed in the first place. There is a very serious danger out there and some people as I said are making themselves rich on this diagnosis. So, there is a danger to treating. I don’t have any problem treating somebody where it’s suspected for a month, but if they don’t get better after that, then you stop.”