- Scott Bauer/USDA
- Deer ticks, also known as blacklegged ticks, are spreading in the US.
- These ticks can carry Lyme disease, babesiosis, and a number of other pathogens including Powassan virus.
- Protect yourself with insect repellent when spending time outside – and pull off any ticks as soon as you see them.
The deer tick, also known as the blacklegged tick, is a fascinating but nasty little creature, and it’s spreading.
The tiny arthropods carry Lyme disease – the serious illness that we most associate them with – but that’s not their only threat.
“One thing that people really need to be aware of is that Lyme disease is not the only pathogen that’s out there – there’s quite a few of them, [including] probably quite a few that we haven’t discovered yet,” Rafal Tokarz, an associate research scientist at Columbia University’s Mailman School of Public Health, told Business Insider.
The deer tick, which as far as we know carries more illnesses than any other tick, “has been expanding its range enormously in the last 30 years,” according to Durland Fish, a professor of epidemiology at the Yale School of Public Health. Before the early 70s, it was largely unknown outside the Northeast, but now the deer tick has spread north, south, and west.
The diseases that we know deer ticks spread are all serious:
1. Lyme disease, which is transmitted by ticks infected with the bacterium Borrelia burgdorferi, infects roughly 300,000 Americans every year. It can be treated with antibiotics if caught early, but can cause severe inflammation and nerve and joint pain if left untreated, among other symptoms.
2. When people are infected with babesiosis, parasites infect and destroy red blood cells. Not everyone shows symptoms, but it can be life-threatening for some at-risk patients. It’s “like tick-borne malaria,” Fish said, and is the most important contaminant of the blood bank right now.
3. Anaplasmosis is spread by another bacteria carried by deer ticks. It usually shows up a week or two after a bite and can cause fever, headaches, nausea, and general malaise, among other symptoms. If untreated it can be severe, leading to hemorrhage and renal failure. For a small fraction of even healthy patients, it can potentially be fatal.
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4. Deer ticks can also spread the Borrelia miyamotoi bacteria, which Fish said is similar to the bacteria that causes Lyme. Symptoms include joint pain, fatigue, fever, chills, and headache.
5. A relatively recently discovered disease, ehrlichiosis, is spread by deer ticks as well as dog and Lone Star ticks. It’s caused by a bacteria in the same family as the one responsible for Rocky Mountain spotted fever. Symptoms often present like the flu.
6. Powassan virus has been around for a while but has received more attention recently, since the deer tick (which frequently bites humans) started spreading it – the ticks that transmitted the first reported cases in the 1950s rarely bite people. Unlike Lyme, which often takes many hours or even a couple days before it’s transmitted, Powassan infection can occur in as little as 15 minutes. Not everyone who gets bitten by an infected tick gets sick, but if they do, it’s a serious problem since there’s no treatment. In those (still rare) cases, Fish said that there’s about a 50% chance of permanent neurological damage and a 10% chance of death.
The broad range of potential conditions means that doctors don’t even necessarily know what to look for. Even worse, “ticks can frequently be co-infected with more than one pathogen,” said Tokarz. That’s especially true in certain locations like Long Island, New York. One bite could transmit both Lyme disease and babesiosis, conditions that would normally be treated quite differently.
Having two or more illnesses could also change the way the diseases manifest. “We still don’t know whether co-infection exacerbates a disease or doesn’t make a difference,” Tokarz said.”Studies have shown both.”
Unfortunately, we don’t have any good way to control ticks or stop the ongoing expansion, which will lead to more people getting sick.
In the places where people are at risk of picking up a tick, “it is a very important, very severe problem, but the only thing that can be done is to educate people on the dangers of coming into contact with ticks,” Tokarz said.
If you get a tick on you, pull it off right away – don’t bother with urban legends about burning it off. Protect yourself if you are going hiking or spending time in a place where ticks are common by using permethrin-treated clothing for outdoors work and putting on insect repellent that contains DEET.
This post was originally published on June 28, 2017, and has been updated.