Is tick-borne germ causing scourge?

Hey there, time traveller!
This article was published 15/04/2010 (6032 days ago), so information in it may no longer be current.

Fact: Manitoba has one of the highest rates of multiple sclerosis in the country.

Or do we just think we do?

In a recent thesis, Winnipeg researcher Kathleen Crang found that some Manitobans diagnosed with MS and other chronic conditions may actually be suffering from an unwelcome visitor: the borrelia bacteria, a tick-borne "biological evil genius" that causes Lyme disease.

"If I knew someone with MS, I’d be saying, ‘let’s look at those questions,’" said Crang. "If their MS is coupled with heart problems, or skin rashes, or rheumatological involvement, there might be some question as to why."

After all, we’re talking about a bug dubbed "the second great imitator." (Syphilis is the first.) Tests for Lyme disease can be unreliable; many of the disease’s 75 known symptoms are shared by a host of neurological conditions. Case studies have even found that Lyme can produce lesions on the brain like those seen in MS.

That in itself isn’t breaking news. Crang’s thesis, titled Knowledge and Perception of Lyme Disease in Manitoba: Implications for Risk Assessment, found numerous reports in Europe and the United States of Lyme disease being initially misdiagnosed as everything from MS to ALS and fibromyalgia.

But in Manitoba, where Lyme is thought to be almost non-existent, Crang found that doctors may not be on the lookout for Lyme. Could that lack of concern lead to lasting misdiagnoses? "There’s a bit of a disconnect there," Crang says. "It’s an information-flow problem. The fact that individuals are hearing such low numbers of Lyme leads to a perception that Lyme isn’t there."

In a series of interviews for the thesis, Crang found that many Manitoban public health decisionmakers and clinicians didn’t perceive Lyme as a threat to Manitobans, and "did not expect they would see patients with the disease." One clinician told Crang they’d find it "hard… to consider" the risk of Lyme in a patient who "(hadn’t) left River Heights," despite the potential for birds to carry borrelia-bearing deer ticks anywhere in the province.

Crang, 44, is living proof that the mistake can be made. In 1999, doctors told the Fort Richmond Collegiate science teacher that she had MS; an MRI appeared to confirm the diagnosis. But some unusual symptoms, such as joint pain, pushed Crang to investigate her sudden sickness through medical resources.

And so, six months after being told she had MS, Crang learned she didn’t have it after all; a successful antibiotic treatment for Lyme disease followed. "I am so grateful for the questions I asked when I became ill," Crang says. "If one person (diagnosed with) MS is actually able to walk away from MS (because of this work), it would be wonderful."

How many other Manitobans might have fallen between the diagnostic cracks? Crang points to a surprising point: in Minnesota, about 20 people per 100,000 are diagnosed with Lyme per year. By comparison, just 12 Manitobans are known to have contracted Lyme in Manitoba between 1999 and 2007. On the other hand, Minnesota has about half as many MS cases per capita.

To reduce the risk of misdiagnosis, Crang has a relatively low-cost and low-risk suggestion: doctors should provide antibiotics to rule out Lyme in people diagnosed with MS and other chronic conditions Lyme mimics. (Dying borrelia creates a characteristic rash.) "What is there to lose?" Crang asks. "People are living with such serious chronic conditions. If there’s a possibility they do have a Lyme infection, does that not warrant some kind of trial?"

melissa.martin@freepress.mb.ca