“When we try to pick out anything by itself, we find it hitched to everything else in the universe,” posed renowned naturalist and Sierra Club founder John Muir in the 1894 book “The Mountains of California.”

When we pick, then bite into a luscious ripe tomato, we’re on a nutritious journey beginning with the bumblebee vibrating flower pollen. Sun and minerals pushing plant growth. Boosts of lycopene, potassium, calcium fueling our body.

Yet when we find a deer tick latched to our skin for a blood meal, the connection can be injurious, even life-threatening. Deer ticks can carry pathogens. One deer tick bite can bring us low — to a subpar body slogging through months (maybe years) of questions, symptoms, treatments. Tick-borne diseases can cause confusing distress, from chronic joint pain to disabling, even fatal brain damage.

Unfortunately, we’re too familiar with this minuscule culprit: the deer tick, also known as the black-legged tick (Ixodes scapularis). This seed-sized blood-sucker can pack a wallop of huge consequence. The Mayo Clinic lists six parasitic, bacterial and viral diseases the deer tick can transmit to humans. Anaplasmosis. Babesiosis. Ehrlichiosis. Lyme disease. Borrelia miyamotoi disease. Powassan viral disease.

Lyme bacterial disease, surfacing in Lyme, Conn., in 1975, is now common in outdoors lovers’ summer chat. Most people I know have been infected. Four years ago, the 2022 BJM Global Health large-scale meta-analysis reported about nine in 100 North Americans have or have had Lyme borreliosis. Lyme, now counts from 30,000 to 89,000 cases per year, says Wistar Institute Executive Vice President David B. Weiner.

I’ve had Lyme and been treated with antibiotics four times. The spirochete’s left its mark on my brain, though — White Matter Brain Disease affecting memory, body fatigue, balance, fine and gross motor control. We compulsive gardeners work hard to rehab and compensate.

Powassan viral disease

Today my focus is the rare but increasingly seen deer tick-borne Powassan viral disease.

Why? Powassan disease (POW) has no treatment, no vaccine. The Powassan virus infects the bitten person within 15 minutes of contact. No itchy, red rash as alert. POW is difficult to diagnose. POW can cause severe, lingering illness. POW can also be fatal, causing encephalitis or meningitis.

How concerned should we be?

We all should be quite concerned about tick-borne diseases, experts advise. We should do our best to avoid ticks and practice tick-control habits.

As for Powassan, be alert and cautious. Powassan is simmering.

Currently the number of active POW cases in the U.S. is low, notes Dr. Alvaro Toledo, associate professor, Department of Entomology, Center for Vector Biology, Center for Lipid Research at Rutgers University.

“Historically [there are] less than 20 cases per year, although in the last few years we have witnessed a record in the number of cases peaking to 76 last year,” Toledo says.

Most people exposed to or infected by Powassan virus don’t show symptoms or aren’t ill enough to be diagnosed, Toledo adds. Two percent or fewer of us already have Powassan virus in our bodies. “It is a flavivirus, and we know that the seroprevalence in healthy individuals, which is evidence of infection/exposure to Powassan, is roughly 0.5 to 2% depending on the study,” he explains.

Who gets ill? “Age seems to be a risk factor. Older people and young children tend to develop severe neurologic disease more often than young adults,” Toledo adds.

The limited number of cases makes predictions and drawing conclusions difficult. The few people who get ill, can get very sick or die.

“The most severe examples for Powassan are cases that involved encephalitis (inflammation of the brain) that can potentially kill the patient or cause permanent neurological damage,” Toledo says.

Experts agree on 18 cases of Powassan in U.S. in 2026. One case is reported in Pennsylvania. ArboNET at the CDC website shows one reported case in Pennsylvania in 2024, eight in 2025.

Pennsylvania collects adult deer ticks from all 67 Pennsylvania counties and tests them for common and rare or emerging pathogens, says Penn Medicine Infectious Disease specialist Dr. Anne Norris. In the 2023–2024 adult deer tick season (October 2023 through April 2024), Pennsylvania Department of Environmental Protection officials collected and tested 4,629 adult deer ticks. “Among ticks tested, statewide Powassan virus infection rates were 0.4%,” Norris notes.

Context and perspective

“Diagnosing Powassan requires a high degree of clinical suspicion,” Norris explains. “A patient from an endemic region (northeast or upper midwest states), during tick season, who has encephalitis, meningitis or sudden paralysis.”

Norris has “personally seen two cases in the last two years and discussed with colleagues three additional cases. So, not a lot, compared to Lyme, anaplasma and babesia. All five POW patients had extensive outdoor exposure and the two that I saw, both recalled tick attachments.”

How are they faring?

She doesn’t have long-term followup information. Early on she says they were recovering with “significant residual symptoms.”

Overall, “Powassan virus infection can be fatal in about 10% of neuroinvasive cases,” Norris adds. “Fifty percent of POW survivors have long-term problems” such as headache, fatigue and cognitive problems.

Early on, Lyme and Powassan have similar symptoms, Norris says. Differences become distinct as the diseases progress. The symptoms include fever, chills, sweats, headache (more severe with POW) and fatigue (actual muscle weakness with POW). Lyme is far more likely to cause rash, joint and muscle pain, facial nerve palsy and swollen glands. POW is more likely to present with seizures, altered mental status, vomiting and paralysis.

Death from Lyme disease is very, very rare. The vast majority of the estimated 475,000 yearly cases of Lyme disease cause no long-term consequences, Norris assures.

Here in Wyndmoor, my precarious balance, poor memory and painful joints remind me daily that Lyme disease inflicts chronic damage.

No Powassan for me! I’m searching again for my Permethrin spray, though, and stashing handy bottles of DEET in my car and within grabbing distance of front and rear apartment doors. Let’s stay all safe.

Tick bite control checklist

When spending time outdoors in the yard, garden, parks, trails, meadows:

Prevent and protect

Wear insect repellent that contains DEET (≥20%) or another EPA-approved repellent. Reapply as directed.

Walk in the center of trails. Stay away from wooded or brushy areas with high grass and leaf litter.

Treat shoes, socks, pants, shirts, hats, gloves and other wearables with .05% Permethrin as per directions on product labels. Permethrin is an FDA-approved synthetic insecticide for external use only. DO NOT apply directly to skin.

Treat gear and items we carry, such as backpacks or reusable lunch bags, with .05% Permethrin as directed on package.

Check pets daily for ticks, especially after spending time outdoors. Use tick-repellent products.

After exposure

Check clothing, backpacks, reusable lunch bags, tools/equipment and tool or equipment containers for ticks.

Conduct a full body tick check. Shower or bathe within two hours of returning indoors.

Remove attached ticks with fine-tipped tweezers. Lift tick straight up, then tug to detach tick with mouth parts if possible.

Place clothes in a dryer on high heat for 10 minutes to kill ticks.

List compiled with help from the Philadelphia Department of Public Health, Division of Disease Control, www.phila.gov/health/DiseaseControl@phila.gov