Ticks are spreading into new regions of the U.S., increasing the risk of tick-borne diseases across the country [1, 2].
This geographic expansion poses a significant public health threat as populations in previously unaffected areas lack immunity and awareness. The shift is coinciding with a spike in medical emergencies related to these parasites.
Warmer temperatures and climate change are enabling ticks to expand their range [2, 3]. Holly Gaff, a mathematical ecologist at Old Dominion University, said this shift is bringing new threats to regions that previously had few or no established tick populations [1, 2].
Medical data indicates that emergency-room visits due to tick bites have reached their highest level since 2017 [3]. This surge comes during the peak tick season, which runs from May through July [4].
Among the emerging threats is the Powassan virus. Public health data shows there are currently no vaccines or medicines available to prevent or treat the Powassan virus [5]. This lack of medical countermeasures increases the danger for those bitten in newly infested areas.
Beyond human health, the spread is impacting animals. A recently identified canine disease is also emerging as tick populations soar [1]. Experts said that the combination of expanding habitats and the introduction of new pathogens creates a complex challenge for both veterinary and human medicine.
Local health officials recommend increased vigilance during the summer months. Because ticks are moving into areas where they were not previously common, residents may not be accustomed to performing the necessary checks after outdoor activity.
“Emergency-room visits due to tick bites are at their highest level since 2017”
The expansion of tick populations is a direct biological response to shifting climate patterns. As the 'frost line' moves and winters become milder, ticks can survive in northern latitudes and higher altitudes that were previously too cold. This creates a 'blind spot' in public health, where people in newly affected regions are less likely to use repellents or recognize symptoms of tick-borne illnesses, potentially delaying critical treatment.
