DULUTH -- The number of cases varies from year to year, but the trend is unmistakable: More ticks are spreading more disease across the region, impacting more people who spend time outdoors.
Confirmed cases of Lyme disease in Minnesota jumped from an average of 913 each year in the 2000s to an average of 1,203 cases each year in the 2010s, a 32% increase, according to the Minnesota Department of Health.
Not only are more people being diagnosed with tick-borne diseases, as Northlanders and their doctors become more aware of the risks and symptoms, but more ticks in more places are carrying disease.
“When I first got here 17 years ago, it was a relatively low percentage of ticks carrying disease,’’ said Dr. Jane Rudd, a family practice physician at Essentia Health in Duluth. “Now it's more than one out of three ticks. … You have to assume now that if you are bitten, you have a problem.”
Blacklegged ticks also have expanded across the entire region, and anyone who spends time outdoors is vulnerable to a tick bite.
While the bacteria that causes Lyme is present in small mammals like mice everywhere, "there is something magical" about the saliva in the blacklegged tick that can transmit it to people. "It’s the only one, and we don’t know yet why that is," said Benjamin Clarke, professor in the University of Minnesota Medical School, Duluth campus, who heads tick research efforts there.
Nationally, the Centers for Disease Control and Prevention's most recent data shows about 35,000 officially confirmed cases annually across the U.S. But as many as 476,000 people are reported treated for Lyme each year, up 56% from a decade ago.
"This is a serious epidemic," Clarke said. "Unquestionably it’s going to get worse."
Victims of Lyme and other tick-borne illness report myriad symptoms — from the common bull's-eye rash, fever, aches and pain to fatigue and flu-like symptoms, full-body rashes, mood changes, vision problems, cognitive issues and even sleep disorder and heart problems. In some cases severe arthritis symptoms occur, as does Bell's palsy nerve issues.
The good news is that even the most serious cases can be treated, and patients get better, with antibiotics, said Dr. Andrew Thompson, infectious disease specialist at St. Luke’s hospital in Duluth.
“The sooner you seek treatment after that rash appears, and that’s in about 80% of the cases, the less likely you are to have the more serious problems,’’ Thompson said. “‘It’s treatable … the symptoms really do go away."
That happened to Vern Northrup. Twice. Northrup, of Sawyer, an avid outdoorsman who also worked as a wildland firefighter, is outdoors about as much as anyone. And his home in Carlton County is a hotspot for Lyme disease. He was diagnosed with Lyme disease in 1994 and again in 2008.
"Once I got the antibiotics I did get better pretty quick," Northrup said. “I still have some joint problems … but I don’t know if that’s the Lyme or just me getting old.”
About 8% of Lyme victims report chronic, ongoing symptoms, from brain fog to debilitating joint pain, for months, even years after treatment, Clarke noted, and experts aren’t sure why.
Northrup hasn’t stopped going outdoors. He’s just more diligent about making sure no ticks are attached to him when he gets home.
Low snow, ticks ready to go
This year ticks were already reported showing up in March in the Northland thanks to low winter snowfall totals and a fast warmup for spring. Each morning they crawl out of the leaves and duff on the ground, up on to a blade of grass or a weed, stick their arms out and wait for a warm-bodied host to walk past.
"Our cat picked up a deer tick already on March 26," said Larry Weber of Barnum.
An avid naturalist who writes the weekly Northland Nature column in the News Tribune, Weber says he takes precautions like wearing light-colored clothing so it's easier to spot ticks, and performing diligent tick checks when he gets home.
“As someone who has had Lyme disease a couple of times, I take it seriously,” Weber said.
While ticks are already out and people may already be exposed to tick-borne disease if they spend time outdoors — turkey hunters, mushroom pickers and hikers — it’s not until June, July and August that the number of cases increases dramatically in the Northland as more people are outdoors during the warmest months. Cases can continue into November during years with warm autumns.
DEET, permethrin and a shower
Thompson and Rudd join virtually all other experts in warning people to protect themselves when outdoors in fields or woods. That includes wearing a DEET-based insect repellent on your skin and using permethrin tick repellent on clothing. Multiple studies have found that DEET in concentrations of around 30% are safe for human use. Permethrin isn't approved for use on human skin but can be sprayed on clothing.
"And take a shower when you get in," Thompson said. "You can remove a lot of ticks just by showering."
If you do find a blacklegged tick crawling on you, don’t panic. If it’s small and still moving there’s little chance for infection. Even if it’s attached from that day’s excursion outdoors, Thompson noted, you are probably OK. A tick must be attached for about 36 hours to transmit disease into your body.
"We tell patients that if they think the tick has been attached for 24 hours or more, let us know. Call us," Rudd said. Sometimes all that’s necessary to prevent painful symptoms is a video chat with your doctor and a prescription for an antibiotic.
Patients who wait until they have full-blown Lyme symptoms to seek treatment may have to take antibiotics for two weeks, or even up to 30 days, Rudd noted.
Mouse tick a better name
Blacklegged ticks were once commonly called deer ticks. But a better nickname would have been mouse ticks. According to several studies, the number of white-footed field mice around is a good indicator of how much tick-borne illness is around. (To confuse matters even more, white-footed mice are often called deer mice and in fact aren’t even real mice.)
“People living in northern and central parts of the U.S. are more likely to contract Lyme disease and other tick-borne ailments when white-footed mice are abundant,’’ a study in the journal Ecology noted. “Mice are effective at transferring disease-causing pathogens to feeding ticks.”
Fluctuations in mouse populations — due to predators, weather or other factors — may be one reason Lyme disease cases fluctuate from year to year even as they trend up over the long-term. In some areas, researchers are working to see if increasing predators that eat mice can effectively reduce mouse populations and thus the rate of Lyme disease.
UMD’s Clarke said that while the white-footed mouse carries most of the disease spread by ticks, it may be birds that are spreading the ticks to more places. Mice, ticks and even most larger mammals like deer spend most of their lives in a relatively small area (ticks usually within a few feet of where they were born).
"You may have canines or even cats (wolves, fox, bobcats, etc.) moving the infected ticks around," Clarke said. “But the research that looks most interesting now is on birds transporting ticks over much larger areas.’’
Lyme disease in Minnesota, 2018*
Confirmed cases: 950
Probable cases: 591
62% were men
The median age was 44
41% had serious symptoms such as arthritis or Bell’s palsy
69% of the cases were in June and July
*Most recent year data is available for
Source: Minnesota Department of Health
Other ticks, diseases moving north
The most common offender for tick-borne disease in the Northland is the blacklegged tick, which can spread babesiosis, anaplasmosis and the emergent Powassan virus in addition to Lyme.
Lesser-known is the lone star tick, which in recent years has moved north into Minnesota. Named for the single white dot on the back of the female tick — the ones that bite — the lone star tick carries several pathogens, including tularemia, southern tick-associated rash illness and ehrlichiosis. Research published in the journal Emerging Infectious Diseases from the Centers for Disease Control suggests that disease caused by the lone star tick is increasing and seriously underdiagnosed.
The lone star tick also carries the bizarre alpha-gal bacteria that can spur a severe allergic reaction to meat. It first surfaced in the southeastern U.S. and was only as far north as Iowa just a few years ago. But in recent years, cases have been popping up in Minnesota, even as far north as Duluth.
Source: Minnesota Department of Health
Tick-borne illness symptoms
The symptoms of tick-borne illnesses are not always easy to diagnose. Nearly all tick-borne infections include possible flu-like symptoms, but other symptoms vary by disease:
Lyme: The most common symptom is a bull’s-eye rash that often occurs at the site of the tick bite. Other symptoms can include joint pain, muscle aches, severe headache, heart palpitations and joint swelling.
Anaplasmosis and Ehrlichiosis: Both of these illnesses present in similar ways so lab testing is required to determine which is the cause. Common symptoms include flu-like illness, fever, chills, muscle aches and sometimes gastrointestinal symptoms. Rashes are not common.
Babesiosis: Babesiosis includes fever, chills, and fatigue. Because Babesia microti infects red blood cells, it causes hemolytic anemia, which can be detected via a blood test.
Doxycycline works fast if taken soon
According to the Centers for Disease Control and Prevention: In areas that are highly endemic for Lyme disease — including north-central Minnesota and northwestern Wisconsin — a single prophylactic dose of the antibiotic doxycycline (200 mg for adults or 4.4 mg/kg for children) may be used to reduce the risk of acquiring Lyme disease after the bite of a high-risk tick. That’s only if the tick is identified as a blacklegged tick and has been attached for 24 hours or more. People who spend a lot of time outdoors, especially away from home, and where medical help may not be immediately available, should consider getting an advance prescription from their health care provider to have the single doxycycline dose on hand.
Source: Centers for Disease Control and Prevention
UMD med school wants your ticks
You can help UMD researchers build a map of blacklegged ticks — Ixodes scapularis — locations across the region as they track down which ones and how many carry Borrelia, the bacteria that causes Lyme disease. The map will help show where tick populations are growing and the relative risk for catching Lyme disease.
When you find a blacklegged tick, remove it with tweezers as near to your skin as possible. Pull firmly and steadily, the barbed mouth parts may not let go easily, but do not wiggle or twist. Continue to apply a firm, steady outward pull until the tick is separated from the skin. Do not handle the tick directly with your bare hands. Avoid crushing or cutting the tick. Please do not submit ticks that you can clearly distinguish as wood ticks, as they do not spread Lyme disease.
For more information go to ixodesoutreachproject.blogspot.com.
Self-report your blacklegged tick online at https://survey123.arcgis.com/share/d8516d3ae76d46e893446711c72e4272
Then mail your tick to: Ixodes Outreach Project, University of Minnesota Duluth, Department of Biomedical Sciences/SMed 332, 1035 University Drive, Duluth, MN 55812.
Free program April 22 on Lyme disease and ticks
The University of Minnesota Duluth’s “Ixodes Outreach Project” has funding from the National Library of Medicine for a virtual public outreach program set for 5 p.m. on April 22. Pre-register to get the Zoom invitation at z.umn.edu/IOP_2021_CommunityOutreachProgram. The program is free and will talk about Lyme disease causes, prevention and research, among other topics. For more information email email@example.com. (Ixodes is the Latin name for blacklegged tick.)
Protect yourself (and your pets) from tick-borne diseases
DEET: Experts strongly suggest using both a personal insect repellent on your skin as well as a repellent that can be applied to clothing. DEET is by far the most effective insect repellent to apply to your skin, including for keeping ticks away. Multiple studies have found that, in concentrations of 30% and under, it's considered safe to use. Other options include picadarin, a synthetic compound first made in the 1980s to resemble the natural compound piperine, found in the plants that produce black pepper.
Permethrin: A repellent that should be sprayed on clothing, or soak clothing in a permethrin solution, to keep ticks and other insects at bay for long periods, often for several washes. (Store treated clothing in a plastic bag to last longer.) Permethrin is considered extremely effective and also works to keep away mosquitos that may be carrying viruses like West Nile and zika.
Clothing: Ticks usually crawl onto people below the knees and then crawl upward. Wear long-sleeved shirts and long pants. Wear light-colored clothes so it is easier to see ticks on you. Tuck pants inside socks to keep them on the outside of your clothing, giving you more time to see and remove them before they get to your skin and start feeding.
Check: Experts suggest checking yourself in front of a mirror after coming in from outdoors, or better yet, have someone else help check you. Hotspots are around the waist, under the arms, inner legs, behind the knees and around the head, including in and around the ears and in the hair. Adults should help check their young children for ticks. Save any suspected blacklegged ticks for identification.
Shower: A good shower after a day outdoors can help remove many ticks.
Remove: Prompt removal of embedded ticks helps reduce the chance a disease will be transmitted. Ticks need to be attached for a day or more to transmit disease to humans. The best method for removing a feeding tick is to grasp it as close as possible to the skin of the host with tweezers or tissue paper. Do not squeeze the tick if possible. Gently, yet firmly, apply steady pressure on the tick until you pull it out. If you try to jerk or twist the tick out, you risk the mouthparts breaking off and remaining in the skin. Clean out the wound with a good germicidal agent, such as iodine, to help prevent infection. (Experts say using tape, alcohol or Vaseline to cover the tick and cause it to voluntarily pull its mouthparts out of the skin is ineffective.)
Save: If there is any question as to whether this tick is a species that can potentially transmit disease, especially blacklegged, save it by placing it in a small container to be identified later.
Watch: For several weeks after a known tick bite, keep watching for symptoms, including a red spot or rash near the bite site, full body rash, neck stiffness, headache, nausea, weakness, muscle or joint pain or achiness, fever, chills and swollen lymph nodes. Call your doctor if you experience these or if you are bitten by multiple ticks in a short time even without symptoms.
Dogs also are susceptible to several tick-borne illnesses, including ehrlichiosis, Lyme disease, anaplasmosis and others. Most veterinarians suggest using a topical repellent medication such as Frontline, K9-Advantix or Hartz Ultra Guard, or a tick collar. Many of those contain permethrin which works well in dogs, but can be fatal to cats. Many vets also suggest getting dogs vaccinated against Lyme disease.
Sources: Minnesota Department of Health; St. Luke’s hospital; Essentia Health; healthline.com.