From the WebMD Archives

July 2, 2019 -- No matter where you are in the U.S., expect to find ticks.

The blood-suckers are in every state – even Alaska and Hawaii.

Ticks are in more places than they’ve ever been before,” says Thomas Mather, PhD, known as “The Tick Guy,” director of the University of Rhode Island’s TickEncounter Resource Center. “Not necessarily more ticks, but in more places. This leads to more people having an encounter.”

Cases of tick-borne diseases have been increasing in the United States for the last 25 years; in 2017, state and local health departments reported a record number to the CDC. Lyme disease in particular has exploded, increasing by 300% in the Northeast and 250% in North-Central states.

Here’s what else you need to know about ticks:

Q. What’s the forecast for ticks this year?

That depends on where you live and a variety of other things, including the number of host animals that the ticks  feed on (such as deer), temperature, rainfall, and humidity. Some types, like the black-legged tick (also known as the deer tick -- the one that carries Lyme disease), thrive in humid conditions. Others, like the Lone Star and American dog ticks, prefer a dry climate. The life cycle for disease-spreading ticks can be 2 to 3 years, so last year’s weather conditions matter, too.

Q. How many types of tick are there?

In the United States, nine different species are known to transmit diseases to humans. Recently a 10th species, the Asian longhorned tick, was found here for the first time. In other countries, it has made humans and animals seriously ill.

Q. Is their territory expanding?

Each species of tick claims a different area of the country, with plenty of overlap. For some types, their reach is growing. For instance, the Lone Star tick, which carries diseases like ehrlichiosis, which causes flu-like symptoms, originated in the southeastern U.S. It has expanded into Northern and Midwestern states. And the black-legged tick, which transmits Lyme, has more than doubled its range over the last 20 years. One species, the brown dog tick, is found in every state except Alaska.

One reason for the black-legged tick’s expansion is the spread of white-tailed deer. They act as the reproductive host for the tick, and they’ve been found in more urban settings -- even in New York City.

Climate change also affects tick activity. Milder winters mean that fewer disease-carrying ticks die in the winter, while hotter, more humid summers give them more time to find hosts and feed.

Q. Can ticks live indoors?

Yes. If you have a pet that lives indoors and out, ticks can catch a ride into your home and stay there.

Depending on the species, they may last for 24 hours or up to several days.

Q. Can ticks survive cold weather?

Yes. Think about it: If ticks die when the temperature drops below freezing, where would next year’s ticks come from?

In fact, black-legged ticks can emerge in a winter thaw -- and they’ll be looking for a meal.

Q. What diseases do ticks transmit?

Those nine species carry a dozen different diseases, and disease cases from tick bites have doubled in the United States over 12 years. Over the past 2 decades, scientists have identified another seven tick-borne germs that can make you sick.

Lyme disease is by far the most common. In 2017, there were more than five times as many cases as the next most common, anaplasmosis and ehrlichiosis. Others include spotted fever rickettsiosis, babesiosis, and tularemia.

Q. How do ticks transmit disease?

It sounds gross, but they spit germs into your body. Ticks eat blood to survive. They wait on the tips of grasses and shrubs until a human or animal host brushes by, then scramble aboard. From there, the tick seeks out a safe spot and inserts a feeding tube into the skin, which may have barbs to keep it attached, or the tick may secrete a cement-like substance to hold it there. That’s when the tick starts sucking blood, which can go on for several days. While it’s sucking, it’s also spitting saliva. If the tick is carrying a disease, the saliva carries it into your body. The longer the tick stays attached, the greater your risk.

Q. How small can ticks be?

Over the course of their life cycle, ticks come in three sizes. Among the ones that bite humans, black-legged ticks are the smallest. Their larvae are tiny, nearly microscopic, but they don’t transmit diseases -- they pick them up from host animals while feeding. The next stage, nymph, is about the size of a poppy seed. They’re hard to see on your body, which may be why nymph black-legged ticks are most likely to transmit Lyme disease to humans. Adult ticks can also give you Lyme, but they’re bigger, about the size of a sesame seed, so they’re easier to spot and remove before they can pass along the bacteria.

Q. How do ticks compare to fleas?

They’re both small, and they both bite humans, but fleas mostly just make you itch. They can carry plague, a potentially deadly disease, but only 89 cases were reported in the United States between 2004 and 2016.

More common -- but still unlikely -- is murine typhus, which mostly happens in the southern U.S., particularly Texas and California.

Q. How do ticks reproduce?

Most ticks that transmit disease mate while on a host’s body. (Yes, that can mean they’re getting it on, on you.) After feeding on a host animal’s blood, the adult female lays eggs -- from 1,500 to as many as 5,000. Those eggs hatch several months later, and the life cycle starts again: larva, nymph, adult, eggs.

Q. Where do ticks lay eggs?

Not on you! Once the adult female is full of blood, she’ll drop off to lay her eggs somewhere sheltered.

Q. What do baby ticks look like?

Larvae are very small dots, barely visible. But if you look at them under a microscope, you’ll see six legs. Nymph ticks, the next stage, have eight.

Q. Will you feel it when a tick bites?

Probably not. When they’re attaching themselves to a host, ticks secrete saliva that acts like an anesthetic. So if they’re in a hard-to-see spot on your body, you may not notice.

Q. What should you do if you find a tick on your body?

Remove it as soon as possible. But don’t just yank; use a pair of pointy-tipped tweezers. They’ll give you the control you need to grab the tick as close as you can get to the skin. Pull straight up, steadily, without twisting or jerking. The idea is to remove the whole tick in one go, without leaving any of its mouth parts behind.

Once it’s gone, thoroughly clean the skin and your hands with rubbing alcohol or soap and water.

Because it can take a while for a tick-borne disease to emerge, it’s a good idea to hold on to the tick, says Mather. The TickEncounter Resource Center offers “TickSpotters,” a crowdsourcing tool that helps you identify what type of tick you found. “We can’t help you if it doesn’t have a picture,” he says. “Put it in a Ziploc bag. It doesn’t take much space, you can write on it, and you’ll have it if you want to get it tested.”

Q. How can you avoid being bitten?

Ticks can’t jump or fly -- they start from ground level and climb. If you never brush up against grasses or shrubs, you should be fine. But for most of us, that’s easier said than done. When you’re walking through an area with heavier brush, take extra precautions: Tuck your pants legs into your socks, so the tick can’t get to your skin. And if you know you’re in a tick-infested area, wear clothing -- especially shoes, socks, and pants -- treated with permethrin, which repels and kills ticks. Insect repellents containing DEET, which you put on your skin, add more protection, but DEET alone is nowhere near as effective as permethrin.

Once you get home, check your body for ticks: under your arms, in and around your ears, inside your bellybutton, behind your knees, between your legs, around your waist, and on your hairline and scalp.

Show Sources

Thomas N. Mather, PhD, director, University of Rhode Island’s Center for Vector-Borne Disease and its TickEncounter Resource Center.

CDC: “Tickborne Disease Surveillance Data Summary,” “Lyme and Other Tickborne Diseases Increasing,” “Geographic distribution of ticks that bite humans,” “Climate Change Increases in the Number and Geographic Range of Disease-Carrying Insects and Ticks,” “How Ticks Spread Disease,” “Tickborne Diseases of the United States,” “Illnesses on the Rise,” “Tickborne Disease Surveillance Data Summary,” “Vital Signs: Trends in Reported Vectorborne Disease Cases -- United States and Territories, 2004-2016,” “Ticks,” “Tick Bites/Prevention.”

U.S. Department of Health and Human Services: “Tick-Borne Disease Working Group: 2018 Report to Congress.”

Emerging Infectious Diseases: “Enhancement of Risk for Lyme Disease by Landscape Connectivity, New York, New York, USA.” “Tick Larvae: They’re Early, They’re Tiny, They’re Everywhere,” “Protect Yourself,” “Permethrin,”

Medline Plus: “Typhus.”

Alaska Department of Fish and Game: “Watching for Ticks.”

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