15 Useful Facts About Lyme Disease

Stringer/Getty Images
Stringer/Getty Images

As summer nears and you spend more time outdoors in one of the many beautiful natural spots in the United States, be sure to dress for the season—tick season, that is. Some experts say 2017 may be an especially tick-infested year. Deer ticks (Ixodes scapularis) carry a bacteria that causes Lyme disease, an infection from a bacterium that coils waiting in their insect bodies. Lyme-carrying deer ticks are especially prevalent in the upper East Coast, the upper Midwest, northern California, and the Oregon coast. While not every tick carries the bacteria that lead to infection—and some carry other pathogens—it’s best to take precautions to prevent bites, and seek medical attention if you have been bitten. The infection can cause long-lasting damage if not treated early. Here are 15 facts you need to know about Lyme disease.

1. LYME DISEASE IS CAUSED BY COILED BACTERIA.

Lyme disease is caused by the bacterium Borrelia burgdorferi, a spirochete, or tightly coiled bacterium that looks like a tiny spring under a microscope. Spirochetes are very simple, slow-replicating bacteria that require a mammalian or avian host to survive. According to Timothy Sellati, chair of the infectious diseases department at Southern Research, a nonprofit research institution in Birmingham, Alabama, “It takes on the order of 18–20 hours for a single spirochete to divide into two.” That’s incredibly slow, compared to other bacteria like E. coli, which can replicate every 20 minutes. Because Borrelia replicates so slowly, and they don’t reach high numbers, “They do not show up easily in a blood test,” Sellati says.

2. TICKS PREFER A LONG MEAL.

Sellati explains that ticks are very different feeders from mosquitoes, which he calls “hit-and-run feeders.” Ticks will feed over a period of three to five days before they become fully engorged. Female ticks generally only take three “blood meals,” he says, in the duration of their lifespan. They take one blood meal after hatching from their egg into the larval stage, another after they molt into their nymphal stage—the stage where they are most likely to bite you—and a final “big meal” in preparation for laying thousands of eggs. Adult male ticks generally don’t feed, he says.

3. THEY ARE A VIRULENT DISEASE VECTOR …

When an infected tick bites a human, the waiting spirochetes—which live essentially dormant in the tick’s gut until environmental cues such as changes in temperature and oxygen availability awaken them—travel from the tick’s gut to its saliva glands. “From the saliva glands they can literally be spat into the bloodstream that the tick is feeding on,” Sellati says. Once they enter the bloodstream, spirochetes travel to various body tissues, because if they stay too long in the bloodstream, they’ll get killed by their host's immune system. “Once it gets away from site of inoculation, it shows a bias toward joints, heart, central nervous system,” Sellati says.

4. … WHICH LEADS TO INFLAMMATION.

“The bacteria has components that are very effective at eliciting an inflammatory response,” Sellati explains. While Borrelia don’t produce toxins like other bacteria, they do incite inflammation in sensitive parts of the body such as the joints, heart, and brain. “That inflammatory response is important to help kill and clear the spirochetes, but it causes collateral damage as well.”

5. INFECTIONS MAY BEGIN WITH A BULL'S-EYE.

The first symptom to look for in about 80 to 90 percent of Lyme cases is a telltale rash of an infected tick bite, called an erythema migrans (EM) rash, which looks a lot like a red bull's-eye, and usually appears at the site of a tick bite within seven to 14 days, according to the American Lyme Disease Foundation. However, the rash does not appear in every instance of Lyme disease, so if you’re bitten, you should visit a doctor immediately. You may also experience flu-like symptoms or joint pains in the first month after the bite.

6. DON'T WAIT TO GET TREATMENT.

If you don't see the tick bite, and don't treat early symptoms, the spirochetes continue to spread throughout your body and can cause more severe symptoms, including fatigue, stiff or aching neck, tingling or numbness in your extremities, and even paralysis of your face. Even more debilitating symptoms of later-stage Lyme disease can include severe headaches, painful arthritis and swelling of joints, cardiac abnormalities, and central nervous system debilitations leading to cognitive disorders.

7. IF CAUGHT EARLY, IT'S USUALLY HIGHLY TREATABLE …

When the disease is caught in its early stages, and treated with antibiotics, it’s curable, Sellati says. Even later stages of the disease can be treated, but the longer an infection goes untreated, the more severe the symptoms and damage can become.

8. … BUT SOME PATIENTS EXPERIENCE SYMPTOMS FOR MUCH LONGER.

Scientists are not entirely sure why a subset of patients have recurrent symptoms of the illness in the months and even years following treatment, known as post-treatment Lyme disease syndrome. “It’s not clear if there is a persistence of live replicating bacteria in some immune privileged niche where they’re protected from exposure to antibiotics,” Sellati says, or if it’s simply the subsequent inflammation stirred up in the body that refuses to go back to normal. “What drives that is not entirely clear.”

9. YOUR GENETICS MAY DICTATE YOUR TREATMENT.

Sellati’s lab has been exploring whether genetics plays a role in who recovers after treatment and who doesn’t. “We have some evidence that your genetic makeup can actually predispose you to developing post-treatment Lyme disease syndrome," Sellati says, and adds it will require more research. They believe they might be able to isolate genetic markers that will tell doctors if antibiotics alone will work, or if the patient might need additional treatment.

10. FEAR THE ENGORGED TICK (BUT DON'T PANIC).

The good news is, even if a tick bites you, if it isn’t yet fully engorged on your blood, chances are good it hasn’t been there long enough to transmit the spirochetes that lead to infection. However, it’s always better to be safe, and pay attention to any symptoms that occur thereafter. “The sooner you can remove a tick from your body, whether it’s feeding or not, the better. If the tick is feeding for less than 24 hours, the likelihood of being infected with Borellia is significantly reduced,” Sellati says.

11. AREAS WITH MICE HAVE MORE LYME DISEASE.

Wherever you find mice and deer you’re very likely to find ticks as well. In fact, Sellati says, mice in all forms—but especially the white-footed mouse—are what infectious researchers call a “maintenance reservoir.” Sellati says. “They maintain the bacteria in the wild so that new ticks can acquire it.” Since spirochetes tend to stay in the bloodstream of mice much longer than they do in humans, that’s how ticks have such an endless supply of the bacteria. “If you got rid of all the mice in the world, you would either come very close to or significantly reduce the population of Borellia in the environment. You’d have a significant decrease in Lyme,” he emphasizes.

12. YOU CAN TAKE SIMPLE STEPS TO PROTECT YOURSELF.

Wear clothes with the most coverage possible. Spray yourself with anti-tick sprays. But no matter what, always do a tick check after you return from the outdoors just to be safe. And if you start to feel any of the symptoms mentioned earlier within a month of a tick bite, don’t wait to visit your doctor.

13. CHECK YOUR CREVICES.

Ticks are not opposed to biting you wherever they can reach, but they have a preference for your warm, moist crevices, such as armpits, backs of the knee, groin, base of the head, and nape of your neck.

14. SKIP SOME OF THOSE "TIPS" FOR REMOVING TICKS THAT YOU'VE HEARD ABOUT.

No matter how many YouTube tutorials you’ve watched, Sellati recommends that you do not use heat, like a match or a lighter, to burn a tick off. The same goes for “goops” such as petroleum jelly, alcohol, or hand sanitizer. Since the spirochetes are transmitted through tick saliva, Sellati warns, “If you try to do those things, you’re only going to piss the tick off, and a pissed-off tick spits a lot, and you're more likely to get more bacteria into your bloodstream.”

15. INSTEAD, USE SLOW, STEADY PRESSURE—AND SOME TWEEZERS.

Take a small pair of forceps or tweezers, Sellati instructs, and gently grasp the tick as close to the skin’s surface as possible, “then pull the tick straight up slowly, which pulls the mouth part out of the skin, and then just dab the area with alcohol to disinfect.” A tick’s mouthparts are like tiny barbed hooks, designed to pierce the skin and stay there. “Then they have secretions that cement the mouthparts to the skin, because they have to feed over a long time and they don’t want to be knocked off while they sit and sip.”

The Reason Our Teeth Are So Sensitive to Pain

This woman's tooth pain is actually helping her avoid further damage.
This woman's tooth pain is actually helping her avoid further damage.
champja/iStock via Getty Images

On a good day, your teeth can chew through tough steak and split hard candy into pieces without you feeling a thing. But sometimes, something as simple as slurping a frosty milkshake can send a shock through your tooth that feels even more painful than stubbing your toe.

According to Live Science, that sensitivity is a defense mechanism we’ve developed to protect damaged teeth from further injury.

“If you eat something too hot or chew something too cold, or if the tooth is worn down enough where the underlying tissue underneath is exposed, all of those things cause pain,” Julius Manz, American Dental Association spokesperson and director of the San Juan College dental hygiene program, told Live Science. “And then the pain causes the person not to use that tooth to try to protect it a little bit more.”

Teeth are made of three layers: enamel on the outside, pulp on the inside, and dentin between the two. Pulp, which contains blood vessels and nerves, is the layer that actually feels pain—but that doesn’t mean the other two layers aren’t involved. When your enamel (which isn’t alive and can’t feel anything at all) is worn down, it exposes the dentin, a tissue that will then allow especially hot or cold substances to stimulate the nerves in the pulp. Pulp can’t sense temperature, so it interprets just about every stimulus as pain.

If you do have a toothache, however, pulp might not be the (only) culprit. The periodontal ligament, which connects teeth to the jawbone, can also feel pain. As Manz explains, that sore feeling people sometimes get because of an orthodontic treatment like braces is usually coming from the periodontal ligament rather than the pulp.

To help you avoid tooth pain in the first place, here are seven tips for healthier teeth.

[h/t Live Science]

Arrokoth, the Farthest, Oldest Solar System Object Ever Studied, Could Reveal the Origins of Planets

NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Roman Tkachenko
NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Roman Tkachenko

A trip to the most remote part of our solar system has revealed some surprising insights into the formation of our own planet. Three new studies based on data gathered on NASA's flyby of Arrokoth—the farthest object in the solar system from Earth and the oldest body ever studied—is giving researchers a better idea of how the building blocks of planets were formed, what Arrokoth's surface is made of, and why it looks like a giant circus peanut.

Arrokoth is a 21-mile-wide space object that formed roughly 4 billion years ago. Located past Pluto in the Kuiper Belt, it's received much less abuse than other primordial bodies that sit in asteroid belts or closer to the sun. "[The objects] that form there have basically been unperturbed since the beginning of the solar system," William McKinnon, lead author of one of the studies, said at a news briefing.

That means, despite its age, Arrokoth doesn't look much different today than when it first came into being billions of years ago, making it the perfect tool for studying the origins of planets.

In 2019, the NASA spacecraft New Horizons performed a flyby of Arrokoth on the edge of the solar system 4 billion miles away from Earth. The probe captured a binary object consisting of two connected lobes that were once separate fragments. In their paper, McKinnon and colleagues explain that Arrokoth "is the product of a gentle, low-speed merger in the early solar system."

Prior to these new findings, there were two competing theories into how the solid building blocks of planets, or planetesimals, form. The first theory is called hierarchical accretion, and it states that planetesimals are created when two separate parts of a nebula—the cloud of gas and space dust born from a dying star—crash into one another.

The latest observations of Arrokoth support the second theory: Instead of a sudden, violent collision, planetesimals form when gases and particles in a nebula gradually amass to the point where they become too dense to withstand their own gravity. Nearby components meld together gradually, and a planetesimal is born. "All these particles are falling toward the center, then whoosh, they make a big planetesimal. Maybe 10, 20, 30, 100 kilometers across," said McKinnon, a professor of Earth and planetary sciences at Washington University. This type of cloud collapse typically results in binary shapes rather than smooth spheroids, hence Arrokoth's peanut-like silhouette.

If this is the origin of Arrokoth, it was likely the origin of other planetesimals, including those that assembled Earth. "This is how planetesimal formation took place across the Kuiper Belt, and quite possibly across the solar system," New Horizons principal investigator Alan Stern said at the briefing.

The package of studies, published in the journal Science, also includes findings on the look and substance of Arrokoth. In their paper, Northern Arizona University planetary scientist Will Grundy and colleagues reveal that the surface of the body is covered in "ultrared" matter so thermodynamically unstable that it can't exist at higher temperatures closer to the sun.

The ultrared color is a sign of the presence of organic substances, namely methanol ice. Grundy and colleagues speculate that the frozen alcohol may be the product of water and methane ice reacting with cosmic rays. New Horizons didn't detect any water on the body, but the researchers say its possible that H2O was present but hidden from view. Other unidentified organic compounds were also found on Arrokoth.

New Horizon's flyby of Pluto and Arrokoth took place over the course of a few days. To gain a further understanding of how the object formed and what it's made of, researchers need to find a way to send a probe to the Kuiper Belt for a longer length of time, perhaps by locking it into the orbit of a larger body. Such a mission could tell us even more about the infancy of the solar system and the composition of our planetary neighborhood's outer limits.

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