(CNN) -- As warm weather sends people outdoors, some are encountering tenacious pests with no respect for social distance.
Forget staying 6 feet apart: Ticks go for blood in the hardest-to-reach places on the human body.
Many of those ticks are infected with Lyme disease. The illness, which was first identified in Connecticut in the 1970s, is found in countries across the Northern Hemisphere. It’s the most common tick-borne disease in both the United States and Europe.
And the area where Lyme disease is found is expanding.
Lyme disease is on the rise in the United Kingdom, and climate change is projected to worsen the spread of Lyme across northern Europe.
According to the US Centers for Disease Control and Prevention, there's now a high incidence of exposure in Midwestern, Northeastern and mid-Atlantic states.
And while it's still too soon to say how bad ticks will be this year, some indicators point to a population surge in the early part of the season in the United States. Reported sightings of ticks via the University of Rhode Island's crowdsourced TickSpotters survey were up 80% in March over last year.
It doesn't necessarily mean the tick population increased by that much. The program's director, entomologist Thomas Mather — you can call him "The Tick Guy" — said the increase could reflect higher numbers of ticks, people spending more time outside or a combination of the two factors.
The tick population is likely to fluctuate throughout the season anyway, said Mather, who is a professor in the department of plant sciences and entomology at the University of Rhode Island. "What we see in real time isn't always a good prognosticator for what could be happening a month or two months from now."
By April and May, reports were closer to what Mather saw in 2019. But even if tick numbers hold steady for the rest of the warm-weather months, encounters with the tiny arachnids will remain a serious issue.
Not only can ticks carry Lyme disease, they may bring other illnesses as well. When left untreated, some of these can be deadly for both humans and pets.
And as sunny days send people outside to breathe fresh air amid the pandemic, the risk of contracting a tick-borne disease or infection goes up wherever ticks can be found. Here’s what you need to know about staying tick-safe this year.
What are the most serious tick-borne illnesses?
Worrying about the coronavirus pandemic doesn't mean other threats have gone away.
"There are numerous tick-borne pathogens that are on the rise," said Allison Gardner, a medical entomologist and assistant professor of arthropod vector biology at the University of Maine.
Gardner noted that the United States contends with the parasitic infection babesiosis; it's also found in Europe.
The bacterial disease anaplasmosis is a major issue in the United States as well, and has become a more serious threat in the last two decades. More than 6,000 cases were reported to the CDC in 2018, up from 348 cases in 2000, when data for the disease were first collected.
As with Lyme disease, early symptoms of anaplasmosis include fevers, chills, headaches and muscle aches. Antibiotics are effective against anaplasmosis, but if left untreated, the disease can be fatal. Those with compromised immune systems are at especially high risk.
In Europe, the viral tick-borne encephalitis is a problem, with 3,092 confirmed cases in European Union countries in 2018. There is an effective vaccine against the disease, which can cause fevers, headaches, paralysis and convulsions. (Other tick borne-diseases in Europe include tick-borne relapsing fever, Crimean-Congo hemorrhagic fever and Mediterranean spotted fever.)
The most common tick-borne danger in both the United States and Europe, however, is still from Lyme disease. And the vast majority of cases may go undetected.
Some 30,000 Lyme disease diagnoses are reported to the CDC each year, but the agency estimates that actual cases in the United States may be 10 times higher than that. A 2016 report in the Journal of Public Health estimated 85,000 annual cases of Lyme in Europe, noting that reporting is inconsistent and that many of these cases are likely undiagnosed.
Early symptoms of Lyme disease include fever, chills, headache, muscle aches and a distinctive bull's-eye rash that expands from the bite itself. (Though a rash is a well-known sign of the infection, it occurs in 70% to 80% of cases.)
If left untreated, Lyme-disease symptoms can eventually worsen to include facial palsy, heart palpitations and severe joint pain.
Stay tick-safe in the outdoors
Gardner, the University of Maine medical entomologist, spends her days in the field dragging a light-colored cloth through tick habitats. The ticks grab onto the fabric, where their dark bodies show up clearly.
That's a research trick you can adapt to protect yourself. "Light-colored clothing can make it easier to spot the ticks on you," said Gardner, whose work puts her in frequent close contact with the tiny creatures.
Other ways to protect against ticks include tucking pants into socks. Since ticks crawl up from the ground, this makes it easier to spot them before they slip beneath your clothes.
There are also ways to protect the area outside of your home against ticks. The University of Rhode Island's online Tick Encounter Resource Center recommends a variety of home projects, starting with raking leaves, cutting low-hanging branches and trimming back shrubs.
The kind of plants you have in the yard matters as well. Studies in the United States have found especially high tick numbers in place with the invasive plants Japanese barberry and bush honeysuckle, both of which were introduced as ornamentals.
"Removing these invasive plants in the landscape have the additional benefit of inhibiting exposure to tick-borne pathogens," Gardner said.
Looking for ticks — and what to do if you find one
Even if you're practicing scrupulous tick safety when outside, it's essential to inspect yourself and your kids for ticks when you come back in.
That means a full-body check: Partner with someone who can inspect every corner of your body, or use a handheld mirror to peer into hard-to-see places. Some places where ticks are easy to miss include your ears, inside your belly button, underneath the arms and on the backs of your knees.
(A careful check should take a minute or two — long enough to listen to a few verses of "Ticks," a Brad Paisley song that's the unofficial anthem of vector-borne disease safety.)
Rinsing off can help as well. Showering within two hours of coming inside can reduce the risk of Lyme disease, according to the CDC. When hit with water, unattached ticks may simply wash down the drain.
It's a good idea to check your clothing, too. If you're worried there may still be ticks on your clothes, drying them for 10 minutes at high heat will kill any hangers-on, since washing alone won't do the trick.
Should you find a tick attached to your skin, it's important to remove it as soon as possible.
Have a pair of fine-tipped tweezers on hand, and use them to grasp the tick close to the skin, pulling it off with steady, gentle pressure. (This CDC fact sheet shows the process in more detail.)
If you develop a rash or fever within a few weeks of finding a tick, contact your health care provider.
In areas with a high incidence of Lyme disease, it's a good idea to check in anyway; depending on how long the tick has been attached or embedded, the provider may recommend further treatment or monitoring.
What about your pets?
There are two considerations when it comes to pets and tick safety: keeping them safe, and ensuring you're not exposed to ticks that they bring into the home.
In the United States, dogs are susceptible to tick-borne Lyme disease, ehrlichiosis, Rocky Mountain spotted fever, hepatozoonosis, anaplasmosis and babesiosis. European dog owners must watch out for babesiosis as well.
Some of these diseases can be fatal.
Fortunately, dogs can be vaccinated against the bacterium that causes Lyme disease. (Even during the pandemic, many veterinarians are open for treatments, including vaccinations.)
For protection from other threats, the University of Rhode Island's Tick Encounter recommends combining the vaccination with additional tick-preventative treatments.
Cats do not appear to be susceptible to Lyme disease. In the southern United States, however, they can catch the tick-borne Cytauxzoon felis, a parasitic disease that is often fatal. To protect your cat and your household, it's important to use a tick-preventative treatment if the animal spends time outdoors.
For both cats and dogs, as with people, a thorough visual check is also a good way to screen for ticks. (Read CDC tips for removing ticks from pets here.)
It’s a habit that will protect your pet, while also preventing the arachnids from attaching to a vulnerable human food source: You.