Through the 1970s a group of children and adults in Lyme, Connecticut (in the United States) suffered greatly from several debilitating issues. Symptoms like swollen knees, paralysis, rashes, headaches and severe chronic fatigue were all brought to the attention of the local doctors. It baffled them and hospital stays had become all too common.
These families and doctors were all genuinely confused and the patients were undiagnosed and untreated for years during the 1960s and 70s.
Two mothers from this group in Connecticut began to take notes, conducted their own research and started contacting scientists. The establishment began to study the group’s symptoms and looked for several possible causes. Viral? Bacterial? Fungal? The children had reported skin rashes followed very quickly by arthritis. And in one of the greatest frets of modern day epidemiology, the researchers found that they all recalled being bitten by a tick, in the region of Lyme, Connecticut.
Years would pass and the outbreak in Lyme would pique the interest of another scientist who was studying Rocky Mountain Spotted Fever (also caused by a tick bite). This scientist, Willy Burgdorfer, found the connection between the deer tick and the disease. He discovered that a bacterium called a spirochete, carried by ticks, was causing Lyme.
The medical community honored Dr. Burgdorfer’s discovery in 1982 by naming the spirochete Borrelia burgdorferi.
Borrelia burgdorferi is transmitted to humans through the bite of an infected tick. These ticks can also transmit other diseases and infect pets and livestock. The ticks which spread Lyme are typically no larger than a sesame seed (or the size of a full stop at the end of a sentence). The tick’s saliva contains an anesthetic like substance; so you may not feel the bite.
In most cases, Lyme disease can be successfully treated with antibiotics if it is caught early. But the disease manifests itself through a wide variety of symptoms making it hard to identify especially if you are unaware of being bitten. For example not everyone gets a rash, much less the telltale bull’s-eye rash.
Current diagnostic tests are also unreliable, in part because they depend on the presence of antibodies which take time to develop (and in some cases may not sufficiently develop) for accurate detection. In areas where Lyme disease is relatively new or underreported, some doctors may not think to test for the disease. Some may even be skeptical of its presence.
If misdiagnosed or left untreated Lyme can become a debilitating disease causing years of misery, so it would be a good idea to know how the disease is diagnosed.
The current "gold standard" diagnostic is a two-tiered blood test requiring a first-step ELISA(measurement of the total number of infection-fighting or memory antibodies against Borrelia burgdorferi). If the test is positive it is followed by a confirmatory Western Blot (measurement of antibodies that target a certain number of highly-specific Bb proteins). This diagnostic is an indirect measure of infection, detecting the body's antibody response to infection rather than detecting the Lyme bacteria itself, and has a number of major drawbacks:
- It misses up to 60% of cases of early-stage Lyme disease, as it can take weeks for the body to develop measurable antibodies against the infection.
- It has been shown to have reasonable efficacy in later stages of untreated disease, but is not useful for assessing treatment response or cure following antibiotics.
- Cases have also been described where people test negative with the two-tiered test, yet the bacteria are detectable in their body. This phenomenon is called seronegative Lyme
- It also does not detect other Borrelia species, such as Borrelia miyamotoi that can cause Lyme-like human disease often without the characteristic bull's-eye rash
- There is a high degree of inter- and intra-laboratory variability (a test may be positive according to one lab and negative according to another; even tests run separately within the same lab may yield different results)
- And interpreting results can be frustrating and confusing – for example, what do we do with a test that falls right below the cutoff?
Other tests, including direct detection of the bacteria itself, are available through a number of clinical labs. While used quite frequently, most of these tests have not been through formal controlled clinical trials or the peer review process.
Clearly there are drawbacks with the current standard test and uncertainties around other available approaches. Better diagnostic methods are desperately needed to reliably detect Lyme disease and measure treatment response and cure.
Article is related to
Diseases and Conditions
Lyme borreliosis, Lyme disease syndrome, Tick infection, Tick bite infection, Lyme disease, Tick bite
Lab Tests
Elisa
