As we prepare for summer hikes, picnics, and camping, someone else is preparing for a cornucopia of delectable blood meals: ticks.
In the U.S., ticks can be even more concerning than their disease-carrying summer siblings, mosquitoes. These little parasites are responsible for a number of diseases, some you’ve likely heard of and some that are less familiar: bourbon virus, Colorado tick fever, and heartland virus; the -osises, anaplasmosis and ehrlichiosis; Rocky Mountain spotted fever; hard tick relapsing fever; and soft tick relapsing fever.
One disease I only learned about after moving to the South is alpha-gal, a tick-borne disease that can make you suddenly very allergic to mammal meat.
Ticks (definitely the lone star tick but also potentially other kinds) can sometimes carry a sugar molecule called galactose-alpha 1, 3-galactose (or alpha-gal), which all mammals except catarrhines (which includes apes, humans and old world monkeys) naturally have.
Because we do not have this carbohydrate, exposure to it through the bite of a tick can cause our immune system to recognize it as a threat and mount a response.
Then, when you are exposed to it again (through eating mammal meat) you can have a delayed allergic reaction (about three to eight hours later), which can range from mild to full blown anaphylaxis.
The only treatment is to avoid mammalian products that might set it off.
Another example of a tick disease you may not be aware of is babesiosis.
This disease is spread by the bite of the blacklegged deer tick.
Infections are most common in the Northeast and Midwest, and while most people do not get any symptoms from an infection, an unlucky few can experience fever, chills, sweats, nausea, vomiting, headache, and fatigue.
Babesiosis can be particularly dangerous for older people, those with a compromised immune system, or those without a spleen.
While there is no vaccine for babesiosis, there are effective treatments (a combination of antiparasitics and antibiotics), but the tick must be attached to the body for 36-48 hours for the parasite to transfer to the host’s blood, so it’s important to do tick checks when you return from the outdoors to limit your risk of exposure.
The biggest tick-borne threat that most people are aware of is Lyme disease.
Caused by the bacteria Borrelia burgdorferiand spread by those same pesky blacklegged deer ticks, it’s the number one vector-transmitted disease in the U.S.
Nearly 90,000 cases were reported to the CDC in 2023, but an estimated nearly half a million cases are diagnosed and treated per year.
Diagnosis typically happens through a combination of laboratory and clinical tests.
One of the most classic clinical signs of Lyme is what’s known as a erythema migrans rash, which typically develops around seven days after a bite and can spread out over several days.
The rash is warm to the touch but not painful or itchy, and can occasionally clear as it enlarges, giving it the appearance of a bullseye, but not always.
The lone star tick can also cause a similar looking bite if it infects someone with what’s known as southern tick-associated rash illness, or STARI.
The cause of STARI isn’t known, so there’s no official diagnostic test or treatment, but since Lyme is uncommon in the south, the geographical location in which someone was bitten is a good indicator of if a rash is from STARI or Lyme.
When it comes to the lab, blood tests are the best bet we have, though they are also unfortunately limited.
The FDA approved Lyme diagnostic tests that look for evidence of antibodies to the bacteria in blood, rather than the bacteria itself.
This has limitations, like the fact that it can’t tell you if an infection is current or just existed at one point, and it could give a false negative if used before there are detectable levels of antibodies or their proteins in someone’s blood.
As a result, many people can be repeatedly misdiagnosed and struggle with Lyme infection for months or years before it’s correctly identified.
While there was a team at the CDC’s division of vector-borne diseases working to develop faster, more accurate diagnostics, they have suffered staffing cuts as a result of HHS’s reduction in force operations.
Untreated Lyme can cause a range of symptoms.
The range of symptoms depends on how long the infection has been progressing for. These include things like fever, rash, irregular heartbeat, arthritis, and brain fog.
With early detection, most people fully recover with two to four weeks of antibiotic treatment.
About 15% of people who complete treatment for Lyme disease continue to experience symptoms such as fatigue, body aches, or difficulty thinking.
This is known as post-treatment Lyme disease syndrome. Like long COVID, it can be difficult to diagnose, and the cause is not completely known.
Theories include persistent tissue damage and inflammation, autoimmune responses, immune system dysfunctions, or even co-infections with other pathogens that cause similar symptoms.
Some believe it could be a persistent infection with the bacteria that wasn’t killed by antibiotics and hides from detection, but there isn’t good evidence that prolonged treatment with antibiotics provides relief.
New research suggests it could also be the result of peptidoglycan (a component of the bacteria’s cell wall) collecting in the liver, causing the immune system to continuously respond to these pieces of the bacteria, causing stress on the body for weeks.
The risk of long term symptoms after treatment make Lyme the kind of disease you really wish there was a vaccine for.
And if you’re wondering why there isn’t one, I have good news and bad news about that.
The bad news is that we had one. LYMErix was a three dose vaccine from GlaxoSmithKline that had a 75% efficacy in preventing Lyme and was approved in 1998.
Unfortunately, it was withdrawn from the market in 2002 after allegations (that were later found to be unsubstantiated) that the vaccine induced a form of arthritis (something Lyme disease itself can cause,) which made its popularity fall in what was already a really limited market of people interested in a vaccine for Lyme disease.
Now, with climate change, the territory of deer ticks and lone star ticks, is expanding, and tick season is increasing in length. That means there are more cases of Lyme and more people who are interested in a vaccine.
The good news is that Pfizer and Valneva have completed the recruitment for their phase 3 trial for a Lyme vaccine.
They recently announced they are expecting the first data rollout by the end of 2025 that could allow them to submit for approval for use in people age 5 or older in 2026.
For now, prevention is still our best option.
A lot of the same advice for mosquito protection applies to tick protection as well.
Try to keep skin covered with long pants and sleeves whenever possible outdoors.
Use bug repellant with DEET or picaridin, which have both been evaluated for safety and efficacy by the EPA and studies for years.
And if you’re worried about the safety of DEET, you don’t really need to be. So long as you are applying it correctly and not like, drinking it, DEET and picaridin are safe for kids
Deet works by masking the scent you produce that makes you attractive to mosquitoes.
So, it’s not like you’re putting something toxic to the bugs on you, you’re basically putting on a very specific anti-perfume, like an invisibility shield.
There have been a few reports of serious adverse events involving DEET and children, but most cases were associated with drinking products that contain DEET or using them incorrectly.
For really little kids, it’s always a good idea to make sure an adult applies the bug spray and uses either a lotion, wipes, or spray it on your hand first to rub into the face to avoid kids accidentally inhaling any.
And if you don’t want to use DEET you can use picaridin, which was developed to resemble the natural compound piperine, which is found in black pepper producing plants, which are known to deter bugs.
It also masks your scent from bugs. It’s been used in places like Australia for a while and has been available in the U.S. since
It’s not associated with any adverse events, but again, we haven’t been studying it as long as we’ve been studying DEET so rare outcomes might not yet be detected.
You can also treat bags and clothing with permethrin, an insecticide used to repel ticks.
Combine it all with tucking your pants into your socks and you’ll be fully geared up on the trails.
It’s also important to walk in the middle of pathways. Ticks can’t fly or jump, and instead use a method known as “questing,” in which they wave their front arms in the air hoping to be picked up by a passing animal who brushes against the plant they’re on.
Once you get home be sure to do a thorough tick check.
Wearing light colored hiking clothes will make this easier).
Put your clothes in the dryer on high for 15 minutes and take a shower to really check in those less gazed upon spots.
If you do find a tick, get it off you as quickly as possible using tweezers to grab close to the head and pull it straight up. Never twist a tick off, because you risk mouth parts breaking off under your skin.
Wash the area with soap and water or rubbing alcohol.
Once the tick is removed you can kill it by putting it in alcohol, placing it in a sealed bag or container, wrapping it tightly in tape, or flushing it down the toilet.
Some people like to keep the tick in case they develop symptoms so they can bring it to a provider if it might help with diagnosis.
While there are companies that can test ticks, it’s not recommended. A positive test doesn't’ necessarily mean the tick was able to transmit a pathogen to you, and a negative doesn’t mean you haven’t been infected by a tick you missed.
Learning how to identify ticks can help you get a better sense of your risk, as some ticks are more likely to carry disease than others.
If symptoms occur, talk to your doctor as soon as possible.
It is also important to mention the difference between post-treatment Lyme disease syndrome and “chronic Lyme.”
Sometimes they are used interchangeably, and sometimes chronic Lyme is used as a catchall for a constellation of symptoms with no other obvious pathology.
As we’ve seen with long COVID, suffering that doesn’t have a clear cause can often be dismissed by our medical systems. Health insurance and private equity increasingly create an ecosystem where providers do not have enough time to spend with patients to figure out the root of their issues.
As a result, people who are genuinely suffering can sometimes become victims to predatory interventions. Because “chronic Lyme” is not a recognized condition, treatments for that diagnosis are not covered by insurance.
This can cause people to pay huge cash sums for unproven treatments out of desperation for relief.
That is why it’s so important we continue to invest in the research we need to figure out why these long-term symptoms persist, even after treatment.
