Repertoire Magazine – June 2021
Tick-borne diseases are serious, seasonal and spreading to broader geographic locations
By Jim Poggi
In this month’s column I plan to highlight some interesting facts about tick-borne diseases. I will share a little bit about which tick-borne diseases are out there, where they are most common and, of course, focus on available lab tests appropriate for the POL and your role in making it happen.
Let’s start with a couple of facts about tick-borne diseases.
First fact about tick-borne diseases
How many different tick-borne diseases are commonly found in the U.S.? We’re all familiar with Lyme disease and the serious complications it can lead to if left undiagnosed for any length of time. But, did you know there are at least 10 other tick-borne diseases? It’s a fact. Some names you may know are Ehrlichiosis, Rocky Mountain Spotted Fever, and Tularemia. There are others less familiar like Powassan Encephalitis, and Anaplasmosis.
While we used to think of strict geographical boundaries for some of these diseases, many, including Lyme disease, are being diagnosed well outside of their initial site of discovery. Lyme is now known to be diagnosed in the Northeast, Northcentral states and Pacific Coast. While less common, it is also creeping into the mid-Atlantic states. For Rocky Mountain Spotted Fever, despite its name and earliest diagnosis in the Rockies, it is most common in the Southeastern U.S.
| The table below provides a useful summary of the most common tick-borne diseases | ||
| Disease | Where encountered | Average Annual Diagnoses |
| Lyme Disease | Northeast, Northcentral, Pacific Coast, Mid Atlantic | 3 million |
| Babesiosis | Northeast, Midwest, Northwest | 200,000 |
| Ehrlichiosis | East, Southeast, Central | 200,000 |
| Rocky Mountain Spotted Fever | Southeast, Atlantic Coast | 20,000 |
| Anaplasmosis | Northeast, Northcentral, Pacific Coast | 6,000 |
| Southern Tick associated Rash Illness | Southeast, Atlantic Coast | Rare; rash mimics Lyme disease |
| Tularemia | Rare, <1,000 cases annually | |
| Colorado Tick Fever | Northwest, Rocky Mountains | Rare; viral rather than bacterial |
| Powassan Encephalitis | Northeast | Rare; viral rather than bacterial |
| Q Fever | Throughout the U.S. is possible | Very rare; <200 cases |
Second fact about ticks
Do ticks REALLY cause these diseases? No, they are the “vector” or carrier. But each disease is caused by a bacterium or virus the tick harbors when it interacts with us. In the case of Lyme disease, the bacterium is Borrelia burgdorferi. So, as you consider lab tests for tick-borne diseases, be sure to check with your trusted infectious disease supplier. Some describe their tests with the name of the disease, such as “Lyme disease”, others refer to the name of the organism that causes the disease.
There is a large and growing number of resources focused on tick-borne diseases, and Lyme disease, in particular, due to its relatively high prevalence and potentially serious aftereffects. One of the best I’ve found is Lyme Disease.org. A link to their home page is below. In addition to your key infectious disease suppliers, this website provides a wealth of useful information to you, and to the customers you serve.
LymeDisease.org – Advocating nationally for quality accessible healthcare for patients with Lyme disease
Testing
Before I take on the testing side of things, it’s useful to consider the question: How important is it for clinicians to have a quick, accurate diagnosis of tick-borne illnesses? Very important. The most difficult issue clinicians face for most of these diseases is that their symptoms tend to be vague and mimic a variety of other disorders, including autoimmune disease and arthritis. Adding to the situation is that left undiagnosed, a number of serious neurological disorders can occur and dramatically impair quality of life. Finally, many of these diseases require complex and lengthy treatment programs. So, tick-borne diseases pass the test of diseases whose diagnosis in the POL “can be used to initiate or modify a patient treatment program”. It is worth noting that some of these tick-borne diseases produce similar rashes and other nearly identical symptoms which make determining which tick-borne illness the patient has can be particularly challenging.
Physician practices which should consider testing for tick-based diseases represent a wide spectrum of locations. Rural practices are likely to see more patients exposed to ticks than urban practices. In addition, rheumatology and other multispecialty practices who encounter patients with vague, difficult to diagnose conditions including muscle and joint aches, rashes that come and go, fatigue, headaches and flu like symptoms would be wise to consider adopting Lyme disease testing along with a range of tests to rule out arthritis including rheumatoid factor (RF), C-reactive protein (CRP) and Erythrocyte sedimentation rate (ESR).
While there are many tick-borne diseases, given the far greater prevalence of Lyme disease, it is the logical choice for POL testing. The CDC proposes a two-tier testing protocol for Lyme disease. They recommend an EIA (ELISA is an example), an IFA (immunofluorescent assay) as a screen, followed by a Western blot test for confirmation. Both tests are designed to detect IgG and IgM antibodies to a wide variety of proteins associated with Borrelia burgdorferi. EIA or IFA is typically used to screen for Lyme disease and Western blot is considered the confirmatory test for patients positive by the screening test. Both EIA and IFA require specialized equipment and considerable operator skill. Practices performing few Lyme tests would be better off considering one of the new instrument-based waived immunofluorescent assays available as a screening test. Positive screening tests still need to be confirmed by a second method, Western blot.
Tick-borne diseases are serious, seasonal and spreading to broader geographic locations. They can also have serious aftereffects, especially if diagnosis and effective treatment is delayed. So, what is the role of the experienced distribution account manager? First off, consider adding Lyme disease and arthritis testing to your core laboratory portfolio. Secondly, be sure to work closely with your trusted infectious disease supplier to form a plan of action early in the spring and make sure to focus on the practices most likely to benefit from adding these key tests to their practice.
Good planning, coordination with your key infectious disease lab supplier and timely, effective communication with the customers most likely to benefit from this laboratory solution will help establish you as a lab consultant in the know.