Clinical data reflects a notable rise in tick-related medical visits. In Wisconsin, the Department of Health Services reported a rate of 44 tick-bite visits for every 10,000 emergency room visits for the week ending April 19. According to Xia Lee, a DHS public health entomologist, this figure is about double
the number of ER visits recorded at the same time last year.
This spike is not isolated to the Midwest. In the Northeast, emergency room visits for tick bites have climbed to their highest level for this time of year in nearly a decade, according to data from the Centers for Disease Control and Prevention. Public health officials observe that the timing of tick activity often overlaps with increased human outdoor activity during the spring months.
Climate patterns and the early tick emergence
Researchers have found that the premature arrival of tick season is linked to shifting environmental conditions. Ticks thrive in warm, humid weather, and recent anomalies have provided an ideal environment for their activity. In Wisconsin, February was nearly 6 degrees warmer than usual, and the state has seen its wettest April on record.
These conditions have a direct impact on the timing of tick emergence. Xia Lee noted that warmer weather is prompting wood ticks to appear about two weeks earlier than normal. When these are combined with the deer ticks already present, the result is a sharp increase in emergency department visits.
“With some of these warm snaps that we get in the winter time, it’s increasing the timeframe that ticks can be active and can spread disease,” Andrew Lewandowski, pediatrician and board member for Healthy Climate Wisconsin
While a harsh or snowy winter might seem like a deterrent, ticks are remarkably resilient. Julie McCarthy, the town of Needham’s assistant public health director for nursing and behavioral health, explained that ticks are really hardy
and utilize long grass, bushes, and burrows to survive cold periods. The result is a population that remains viable regardless of winter severity, waiting for the first warm snap to become active.
The clinical risk of Lyme disease
From a medical perspective, the current season is particularly concerning due to the prevalence of Lyme disease. Dr. Greg Demuri, a professor of pediatric infectious diseases at the University of Wisconsin School of Medicine and Public Health, stated that spring is the most dangerous season for infection. Given the current weather patterns, Demuri noted, I think it’s going to be a big year for Lyme.
The risk is compounded by the high infection rate among the tick population. PJ Liesch, an extension entomologist at UW-Madison, reported that an average of 40 percent of adult deer ticks and 20 percent of juvenile deer ticks are positive for Lyme disease. These ticks have expanded their range from northwestern Wisconsin to nearly every part of the state.
Early detection is critical because the initial symptoms of Lyme disease are often non-specific. Dr. Peter Adler, emergency department chief at UPMC Passavant, explained that most tick-borne illnesses present with symptoms that are indistinguishable from the flu
, such as fever, chills, nausea, and generalized body aches. Without early intervention, the disease can progress to more severe health complications and long-term illness.
Geographic hotspots and reporting trends
While data from WPR highlights the surge in Wisconsin, other regions show significant long-term burdens. According to 2023 data from Johns Hopkins University, New York and Pennsylvania are the top two states for total Lyme disease cases. Pennsylvania recorded 16,671 cases, ranking it second in the nation.
In Pennsylvania, the impact is visible at the county level. Butler County ranks 26th nationally for total cases with 631, with an incidence rate of 318.02 per 100,000 people. This geographic spread underscores that tick risks are no longer confined to deep woods; as Julie McCarthy warned, bites can occur in well-manicured backyards
, though they are more common in long grass.
The steady increase in reported cases over the last decade is not solely due to tick populations. McCarthy noted that the data has been slowly creeping up
due to a combination of factors, including improved reporting processes, an increased desire for testing, and a general rise in public awareness of tick-borne diseases. In Wisconsin, cases quadrupled over the past 20 years, a trend attributed in part to this better recognition.
Prevention and immediate response
For those encountering ticks, the window for preventing infection is manageable through prompt action. Dr. Peter Adler emphasized the importance of removing ticks as soon as they are discovered to reduce the likelihood of the bacteria being transmitted into the bloodstream.
When a tick has been attached for an extended period, medical intervention may be necessary. Health officials stated that treatment for confirmed cases typically involves a course of antibiotics to eliminate the infection. Patients are encouraged to seek professional medical evaluation immediately following a bite to determine if medication is warranted based on the species of tick and the duration of attachment.
- Wearing long clothing to minimize exposed skin.
- Avoiding tall or brushy grass where ticks typically wait on the ends of blades.
- Using insect repellents containing DEET. Julie McCarthy noted that while many associate DEET only with mosquitoes, it is an important part of tick prevention.
Pet owners should also remain vigilant. Sharon Woo, a dog owner in Jamaica Plain, noted that pets often act as carriers, bringing ticks from the outdoors into the home. This highlights the role of domestic animals in the transmission cycle, as ticks carried by dogs can easily transfer to their owners.
