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.”

Lost Your Wallet? You Might Be More Likely to Get It Back If There's Cash Inside

iStock/tzahiV
iStock/tzahiV

Few things can incite more panic than discovering you’ve lost a wallet or purse containing money, identification, credit cards, and/or keys. You wonder if anyone will find it—and if they do, whether they’ll decide to retain your cash using the playground ethics of the "finders keepers" rule.

An ambitious new study in the journal Science has provided at least a partial answer. If your wallet has cash inside, it’s actually more likely for people to return it than if it didn’t have any.

Researchers at the University of Michigan conducted an exercise in civic honesty, dispatching 13 assistants to 355 cities in 40 countries across the globe. At each destination, the assistants were armed with clear wallets that held things like grocery lists and business cards along with an email address. Some wallets had no money inside. Others contained about $13.45 in the local currency. The assistants gave the wallets to employees at banks, hotels, post offices, museums, and police stations, explaining they had “found” the wallet and were in too big of a hurry to contact the owner themselves. They passed the responsibility to the person receiving the wallet. All told, 17,303 wallets were left as proverbial bait to see what the employees might do.

Of the wallets without cash inside, researchers received an email seeking to return roughly 40 percent of them. About 51 percent of the employees attempted to return the wallets containing $13.45 in cash.

These percentages fluctuated by country. In Denmark, 82 percent of wallets with cash were returned. In the United States, the figure was 57 percent. When researchers upped the stakes by including $94.15 in wallets for areas in the U.S., Britain, and Poland, the return rate went up to 72 percent.

It’s difficult to infer motivations for why people returned wallets with more money than less, or none. In a survey, researchers found that people in general described wanting to avoid feeling like a thief by keeping the money. (Respondents were different than the employees who were left with the wallet.) That would explain why returns increased as the dollar amount went up.

The study was limited by the fact that the wallets were left with people who could have presumably been held accountable for not returning them. The research assistant could have returned to inquire about the wallet’s status, while no such concern exists for people finding a wallet in the street. Still, it does indicate that people feel a measure of sympathy for—and moral obligation to—lost money and will make an effort to see it returned.

[h/t Science News]

Some Fish Eggs Can Hatch After Being Pooped Out by Swans

iStock/olaser
iStock/olaser

A question that’s often baffled scientists is how certain species of fish can sometimes appear—and even proliferate—in isolated bodies of water not previously known to harbor them. A new study has demonstrated that the most unlikely explanation might actually be correct: It’s possible they fell from the sky.

Specifically, from the rear end of a swan.

A study in the journal Ecology by researchers at the Unisinos University in Brazil found that killifish eggs can, in rare cases, survive being swallowed by swans, enduring a journey through their digestive tracts before being excreted out. This kind of fecal public transportation system explains how killifish can pop up in ponds, flood waters, and other water bodies that would seem an unlikely place for species to suddenly appear.

After discovering that some plants could survive being ingested and then flourish in swan poop, researchers took notice of a killifish egg present in a frozen fecal sample. They set about mixing two species of killifish eggs into the food supply of coscoroba swans living in a zoo. After waiting a day, they collected the poop and dug in looking for the eggs.

Of the 650 eggs they estimated to have been ingested by the swans, about five were left intact. Of those, three continued to develop. Two died of a fungal infection, but one survived, enduring 30 hours in the gut and hatching 49 days after being excreted.

Because killifish eggs have a thick outer membrane, or chorion, they stand a chance of coming through the digestive tract of an animal intact. Not all of what a swan ingests will be absorbed; their stomachs are built to extract nutrients quickly and get rid of the whatever's left so the birds can eat again. In rare cases, that can mean an egg that can go on to prosper.

Not all fish eggs are so durable, and not all fish are quite like the killifish. Dubbed the "most extreme" fish on Earth by the BBC, killifish have adapted to popping up in strange environments where water may eventually dry up. They typically live for a year and deposit eggs that can survive in soil, delaying their development until conditions—say, not being inside a swan—are optimal. One species, the mangrove killifish, can even breathe through its skin. When water recedes, they can survive on land for over two months, waddling on their bellies or using their tails to "jump" and eat insects. A fish that can survive on dry land probably doesn't sweat having to live in poop.

The researchers plan to study carp eggs next to see if they, too, can go through a lot of crap to get to where they’re going.

[h/t The New York Times]

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