Reducing the Risk of Lyme Disease

Summer has arrived across much of the U.S., and that means more hikes, outdoor work ... and ticks.

The official number of tick-borne disease cases has more than doubled in the U.S. in the past two decades, thanks in large part to growing tick populations, rising heat and humidity and improved tracking of these diseases.

Ticks emerge in the spring and are active through early fall (April-October in the Northern Hemisphere). The little critters can’t fly or leap, so they wait around on branches and in grassy areas where they hope to find a small forest mammal or bird to latch on to.

Lyme disease is by far the most common tick-borne disease; the Center for Disease Control (CDC) officially reports about 36,000 cases each year, but there is reason to believe this is dramatically underreported. The Northeast, upper Midwest and Northwest are hot spots for Lyme disease, but ticks carrying Lyme and other diseases can be found all over the country.

Ticks, which are actually arachnids and not insects, can transmit at least a dozen diseases that affect humans, all of which are notoriously nonspecific and include vague flu-like symptoms like fever and headaches.

Lyme disease is primarily transmitted through the bite of infected black-legged ticks (Ixodes scapularis), which are present from coast to coast (as Ixodes pacificus in the western U.S.). These ticks thrive in wooded and grassy areas, making hikers, landowners and farmers particularly susceptible.

If you do find a tick, don’t panic — most ticks are disease-free, and even if a tick is carrying disease, most tick-borne diseases (especially Lyme disease) aren’t transmitted until about 36-48 hours after the tick latches on.

The early signs of Lyme disease are fever, chills, headache, fatigue, muscle and joint aches and swollen lymph nodes. A characteristic “bullseye” rash, known as erythema migrans, appears in between about 80% of infected individuals.

Antibiotics are generally administered if Lyme is diagnosed or if Lyme is suspected after a high-risk tick bite, so a speedy diagnosis is the best way to prevent the onset of late or prolonged Lyme disease symptoms, which are much more difficult to treat as the disease progresses.  In high-risk areas, a single dose of the antibiotic doxycycline can significantly reduce the risk of contracting Lyme disease following a tick bite.

Lyme disease is caused by the spirochete Borrelia burgdorferi and has a unique lifecycle because it establishes persistent, ongoing infections in various species that ticks can bite. Ticks require a new host at each stage of life (larva, nymph then adult) in order to survive, and their lifecycle lasts about two years.

New understanding of this lifecycle reveals that when humans get infected, the spirochete attempts to establish an ongoing infection by subverting the immune response to survive inside the host. Research in mice has recently debunked the long-held belief that B. burgdorferi hides passively in tissues and, instead, has shown it actively engages the immune system, leading to an ineffective immune response that mitigates but does not eradicate the infection. The research is currently working to enhance knowledge of tick infection pathogenesis, immune responses and pathogen interactions in order to stifle its novel approach.

Tick Removal

Prompt and proper tick removal can reduce the risk of Lyme disease transmission. Use fine-tipped tweezers to grasp the tick as close to the skin’s surface as possible, pull upward, avoiding twisting or jerking the tick, which can cause parts to break off and remain in the skin.

After you have successfully extracted the little blood-sucker, you have two options: save it and get it tested, or get rid of it. Experts recommend sending the tick in for testing to determine if it is carrying any diseases, which can be done either through your veterinarian, state’s agriculture department or check Project Lyme for testing options. If you opt to dispose of the tick, drown it in a container with rubbing alcohol or soapy water, then flush it down the toilet or wrap it in tape and throw it out.

Avoid the temptation to crush it with your fingers, you can absolutely catch whatever it’s carrying if you do this, and never use petroleum jelly or a hot match to kill or remove a tick — these methods don’t get the tick off the skin and can make it burrow deeper.

Prevention Tips

A new vaccine for Lyme disease is currently in clinical trials and shows promise in preventing the disease in humans, but prevention is the only current cure available. If you’re planning to spend time in tick-prone areas, wear long pants, a long-sleeved shirt and spray your clothes with 0.5% permethrin ... and while we know it looks dorky, tuck your pants into your socks and wear a hat.

After your adventures, be sure to shake off your clothing outside, shower within two hours and do a full body check on yourself and your loved ones — ticks prefer warm areas, like armpits, but they’ll latch on wherever they can, and they can be difficult to find.

When caught early, tick-borne diseases can be treated so consult a doctor if you suspect you may have been bitten by a tick, especially if you experience those familiar flu-like symptoms. In high-risk areas, a single prophylactic dose of the antibiotic doxycycline can be used to reduce the risk of acquiring Lyme disease after a tick bite.

Symptoms in Humans

As the bacteria begins to spread, severe headaches, neck stiffness, additional rashes, arthritis with severe joint pain and swelling, facial palsy, heart palpitations and inflammation of the brain and spinal cord take hold.

One of the biggest problems with treating Lyme disease in humans is that the best way we know right now is with a broad-spectrum antibiotics, but antibiotics come with side effects. One of them is that they wipe out your gut microbiota, which is crucial for maintaining health and could potentially do further harm. Another hurdle is the illness’ ability to avoid eradication that leads to the well-documented long-term impacts.

Since venturing into tick habitat is inevitable, a vaccine is really the only viable path to prevention. Our warming world is causing ticks that are infected with Borrelia to spread further and further, so finding impactful antigens on the pathogen to determine what to target to make the best vaccine. There’s also work currently being done on using mRNA vaccines that target tick salivary proteins and trigger an immune response that inhibits the tick from establishing good feeding and might prevent transmission.

Tick-Proofing Your Property

While we wait for a vaccine, it’s important to focus on preventive measures. Keep your grass cut short and clear of brush and leaves, as ticks tend to congregate in these areas. Since ticks love animals, installing fencing can also assist in keeping them out of your yards and pastures. Additionally, using acaricides, when applied professionally and in small doses, can help reduce tick populations.

With peak-tick season upon us, landowners and farmers must remain vigilant in their efforts to prevent Lyme disease by staying informed about the latest research and public health initiatives that can protect themselves, their families and their livelihood from the dramatic impacts of this serious disease.