A Better Way to Diagnose Lyme Disease and Other Tick-Borne Illnesses

This summer, a record number of Americans are getting tick bites, exposing them to Lyme disease and other potentially debilitating conditions. Yet obtaining an accurate diagnosis can sometimes be frustrating and challenging. Existing tests can lack accuracy, especially in the early stages when treatment is of utmost importance. Additionally, most tests for tick-borne diseases cannot detect more than one infection simultaneously—a problem because ticks often carry multiple pathogens.

Tick-borne microbes can cause similar symptoms that make them challenging for doctors to tell apart, explains Rafal Tokarz, PhD, associate professor of epidemiology in the Center for Infection and Immunity (CII) at Columbia University Mailman School of Public Health and an expert in tick-borne pathogens. Tokarz and colleagues at CII are developing more sensitive tests that can simultaneously screen for multiple infections. 

“Because of their small size, ticks are extremely difficult to spot on the body, and when some of the microbes they carry get in our blood, they can be very difficult to detect, at least early on,” Tokarz says.

Diagnosis of tick-borne diseases is a pressing public health concern, particularly as ticks are rapidly expanding into new areas, likely driven by climate change. Until recently, the lone star tick was primarily found in the South. Now it is one of the predominant species found in the Northeast, along with the black-legged tick and the dog tick. The black-legged tick, in turn, is expanding its reach north into Canada. Each tick species carries microbes that can lead to a variety of illnesses, such as Lyme Disease, babesiosis, and Rocky Mountain spotted fever, among others. Bites of the Lone Star tick have also been shown to cause alpha-gal syndrome (an allergic reaction to red meat). New invasive tick species, such as the longhorned tick or the Gulf Coast Tick, have now been found in the Northeast and may present an additional risk.

Developing New Diagnostics

In an ongoing effort to improve the diagnosis of tick-borne diseases, Tokarz and colleagues have adapted genetic sequencing technology that analyzes DNA and RNA to detect the specific genetic sequences related to the pathogens ticks carry. The Tick-Borne Disease Capture Sequencing Assay (TBDCapSeq) promises to revolutionize the diagnosis of tick-borne disease by offering a single test to identify and distinguish between Borrelia burgdorferi, the pathogen responsible for Lyme disease, and all other tick-borne pathogens. The platform is based on a similar technology developed by CII scientists to detect viruses and bacteria.

Using TBDCapSeq, Tokarz and his team analyzed blood samples taken from 99 patients with a diagnosis of Lyme disease based on symptoms like headache, fever, and joint pain (more severe cases can lead to infections of the heart and central nervous system). The results, published in the journal Frontiers in Microbiology, were an improvement over traditional molecular tests. It detected seven positives for tick-borne disease, compared to only one positive using a conventional PCR test. Far from perfect, Tokarz admits, but he believes the technology will improve over time. (At present, the TBDCapSeq is not available in a clinical setting.)

Another advantage of the CII platform over traditional PCR is that it can simultaneously test for all known tick-borne pathogens. In another study published in mSphere, Tokarz found that approximately half of adult ticks carried more than one pathogen—an important finding because not all tick-borne diseases are treated the same way.

Currently, Tokarz and his team are working to boost the test’s sensitivity while also making it more affordable, user-friendly, and compact. Simultaneously, they’re developing an improved antibody test for Lyme disease that can be self-administered at home. This test is called a lateral flow test and is similar to a traditional COVID-19 home test. Except here, instead of using a swab, a patient would use just a drop of blood.  

“This test works like an at-home glucose test,” said Tokarz. “All you’d need is to place a drop of blood from a finger stick on the test, wait about up to 30 minutes, and you get the result.” Tokarz and colleagues are in the process of commercializing the test.

How to Protect Yourself from Tick Bites

Any time you’re outdoors, it’s a good idea to regularly pause and make sure you don’t have ticks on your clothes or your pet doesn’t have any on their fur. If you find ticks on your clothes or fur, you can remove them with tweezers, brush them off, or use a sticky substance like a lint roller. Wearing light-colored clothing, long sleeves, and tucking your pant legs into your socks will help keep ticks from biting your skin. However, you should still always stop to check yourself and remove ticks before they bite.

When Using Tweezers to Remove Ticks, Be Gentle

To remove a tick, use tweezers to pull upward with steady, even pressure. Don’t twist or jerk the tick, and don’t use petroleum jelly or a match to burn it off. Once you have removed the tick, thoroughly clean the bite area and your hands with rubbing alcohol or soap and water.

Avoid Leaf Foliage or High Grass and Use Insect Repellent

Ticks are usually found on low vegetation, leaves, or blades of grass. If you plan to be in a wooded, leafy area, spray your clothes with permethrin ahead of time. For your skin, use a repellent that contains 20 to 30 percent of either DEET or picaridin, or a repellent containing 30 percent of oil of lemon eucalyptus. Ticks like dark, humid spaces, so a cut lawn can reduce the number of ticks. Avoid contact with areas with dense leaves and overgrowth.

The black-legged tick, the species that carries the microbe that causes Lyme, is a common tick in New York State. If it’s removed within 24 hours, you substantially reduce the risk of acquiring Lyme disease. In most cases, the tick must be attached for 36 to 48 hours or more before the Lyme disease bacterium can be transmitted. If the tick was on longer than 36 hours or if you feel sick after a tick bite of a shorter duration, it’s a good idea to see a doctor.

Tick tips and background information courtesy of NewYork-Presbyterian Health Matters.