Entomological Society of America
Entomological Society of America

Lyme Disease-Spreading Ticks Now in Almost Half of U.S. Counties

Entomological Society of America
Entomological Society of America

Doctors depend on scientific research to inform the diagnoses they make and the treatments they recommend. When that information is out of date, the doctors and their patients are at a real disadvantage. That’s certainly the case with Lyme disease research. A new report released this morning shows that Lyme disease-spreading ticks can now be found in nearly half of all U.S. counties—a 50 percent increase since the last prevalence study in 1998.

Rebecca Eisen is a biologist at the U.S. Centers for Disease Control and Prevention (CDC). When she realized that the last national survey of tick distribution had been completed nearly 20 years ago, she decided it was time for an update. To ensure that they could compare their results to those from 1998, Eisen and her colleagues used the same techniques employed in the earlier study. They tabulated reported sightings of the blacklegged tick (Ixodes scapularis) and the less-common western blacklegged tick (Ixodes pacificus), both commonly known as deer ticks.

Blacklegged tick. Image credit: Gary Alpert, Harvard University, Bugwood.org.

The results were alarming. The range of I. scapularis has expanded into 45 percent of U.S. counties. That’s a 50 percent increase from 1998, when the tick could only be found in 30 percent of counties. The tick’s territory increased most dramatically in northern states and remained fairly stable in the South. Eisen and her colleagues also tracked the range of the less-common I. pacificus, which seems to have remained relatively steady. In 1998, western blacklegged ticks were reported in 3.4 percent of counties; by 2015, that number had only risen to 3.6 percent.

The map on top is from 1998, and the one below it is from 2015. Red indicates a county where I. scapular is is established, and blue indicates that it has been reported. Green indicates a county where I. pacificus is established, and yellow indicates that is has been reported. Image credit: Entomological Society of America.

While the majority of patients with Lyme disease can make a complete recovery if they’re treated soon after infection, the research is still vital. As it is now, diagnosing the disease can be lengthy and complicated. A bullseye rash is a pretty good sign that a person has been infected, but many people never develop a rash. The most common symptoms of Lyme—fever, headache, and fatigue—are easily mistaken for symptoms of the flu or a viral infection, and blood tests for Lyme disease are notoriously imprecise.

This research could help doctors spot the disease faster, by knowing if their patients have been exposed to Lyme disease-spreading ticks.

“This study shows that the distribution of Lyme disease vectors has changed substantially over the last nearly two decades and highlights areas where risk for human exposure to ticks has changed during that time,” Eisen said in a press release.

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3 Simple Ways to Stay Tick-Free This Summer
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As the weather gets warmer, you no doubt want to don your favorite shorts and get out in the sunshine. Unfortunately, shorts season coincides with tick season, and we're in the midst of what one expert calls a "tick explosion."

Tick expert Thomas Mather of the University of Rhode Island told Boston 25 News that warm weather is going to lead to a particularly bad summer for ticks. The blood-sucking bugs aren't just annoying—they spread Lyme disease and several other serious illnesses, including a pathogen that can cause a sudden allergy to meat.

There are several precautions you should take to stay safe from ticks and the risks they carry during the high season, which usually lasts from April to September, though some ticks can stay active year-round as long as it's above freezing. While ticks usually live in grassy or wooded areas, you should be careful even if you live in the city, because pathogen-spreading ticks can still be hiding in urban parks.

Tick prevention begins when you get dressed. Wear long sleeves and pants, and if you're in a tick-prone area, tuck your pants into your socks to better protect your legs. Opt for light colored clothing, because it's easier to see bugs against a light color versus a dark one.

You'll want to invest in insect repellent, too, for both you and your pets. The CDC recommends treating your clothing (and tents, and any outdoor gear) with permethrin, an insecticide that you can apply to fabric that will last through several washes. Permethrin not only repels ticks, but kills them if they do manage to get onto your clothes, and you can buy socks and other clothing that come pre-treated with it. Insect repellents with DEET are also effective against ticks.

Since ticks are most likely to make their way onto your feet and ankles, make sure to treat your shoes and socks. And since your dog is more likely to get a tick than you are, make sure to get Fido a tick collar or some other kind of tick medication.

Most of all, you just need to stay vigilant. When you come inside from the outdoors, check your body for any ticks that may have latched on. Ticks can be as small as a poppyseed, so make sure to look closely, or ask someone else to check hard-to-see places like your back. And since they like moist areas, don’t forget to give your armpits and groin a careful look. If you do catch a tick, remove it as soon as you can with a pair of tweezers.

Best of luck out there.

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Watch a "Trained" Spider Named Kim Leap Six Times Its Body Length
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Jumping spiders are cold-blooded assassins, masters of disguise, and just maybe a little quicker on the uptake than we're really OK with. For a study published in the journal Scientific Reports, a team of researchers from the University of Manchester "trained" one special jumping spider named Kim to leap in their experiment, all with the goal of demystifying the mechanics behind jumping spiders' abilities.

Kim was one of four regal jumping spiders (Phiddipus regius) the researchers brought into the lab for a close examination of how their bodies move as they leap and land. A jumping spider can clear up to six times its body length, which ranges from 0.04 to 0.98 inches—about the equivalent of a three-story building, relative to the spider's body size. For comparison, the farthest a human can jump is roughly 1.5 body lengths.

The researchers created an experiment chamber with platforms at varying distances from one another, then tried to coax the spiders into it. Only Kim would even enter. The researchers moved Kim between the take-off and landing platforms until she "became familiar with the challenge," they write. No tasty bait or stimulation (like blowing air) was used to motivate her. Still, her eventual familiarity with the task potentially implies some sort of learning. So even though she wasn't following orders, she figured out how to navigate the experiment's challenges—an impressive achievement for a spider about the size of an aspirin.

Using ultra-high-speed and high-resolution cameras, the researchers then filmed Kim's jumps to study how the arachnid moved her body when navigating a short jump equal to two body lengths; a longer jump equal to six lengths; and jumps between platforms placed at different heights. They found that Kim cleared shorter distances quickly and at low angles, thus sharpening her accuracy and boosting her chances of catching any prey that might be waiting at her destination. For longer jumps, she was more conservative with her energy, but her accuracy suffered.

Jumping spiders are excellent hunters, thanks in part to their precision ambushing skills. They also boast super-powered senses that help them locate their next meal before making their attack. Fine hairs on their legs allow them to "hear" subtle vibrations, and their eight eyes are sharp enough to track laser pointer lights.

This family of spiders also uses a hydraulic pressure system to move their legs. It helps jumping spiders extend their limbs, and some researchers have theorized that it also allows them to jump such great distances. According to the new study, that's not the case: "Our results suggest that whilst Kim can move her legs hydraulically, she does not need the additional power from hydraulics to achieve her extraordinary jumping performance," study co-author Bill Crowther said in a press statement. That means the jumps in the video below are made possible by Kim's muscle power alone.

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