Tick bite-related emergency room visits across most regions of the United States have reached their highest seasonal levels since 2017, according to CDC Tick Bite Tracker data. In April 2026, approximately 71 per 100,000 ER visits were tick-related, more than double the historical average of roughly 30 per 100,000. Medical experts are warning Americans about increased risks of Lyme disease and other tick-borne illnesses as the geographic range of disease-carrying ticks continues to expand.
The surge in ER visits comes as doctors report significant increases in tick-borne disease diagnoses across the country. The highest rates of tick bite ER visits are occurring among children younger than 10 and adults aged 70-79, according to the data.
Tick Population Expansion Drives Health Concerns
Dr. Steven Goldberg, a family medicine physician at UofLHealth in Louisville, Kentucky, and chief medical officer at HealthTrack, explained the scope of the growing problem.
“Over the past three decades, the geographic range of the blacklegged tick has expanded significantly, and with it, the risk of Lyme disease and other Ixodes-transmitted infections,” Dr. Goldberg said.
He pointed to specific regional changes as evidence of the expanding threat.
“The Ohio River Valley region is one of the most striking examples — Lyme disease cases in Ohio have increased roughly 10-fold over the past decade, likely driven by the convergence of Northeastern and Upper Midwestern tick populations meeting in that corridor,” Dr. Goldberg explained.
Climate factors are contributing to the expansion of tick habitats across the country. According to Dr. Goldberg, warmer, wetter conditions allow ticks to survive in habitats that previously would have been too cold.
“As temperatures rise and precipitation patterns change, ticks are able to spread northward and thrive in new ecosystems,” he said.
What We Know So Far
The CDC Tick Bite Tracker data confirms that April 2026 saw tick bite ER visits at approximately 71 per 100,000, compared to a historical seasonal average of roughly 30 per 100,000. This marks the highest seasonal level recorded since 2017.
Approximately 476,000 Americans are diagnosed and treated for Lyme disease annually. Over the past 20 years, Lyme disease cases have increased two- to threefold nationwide.
The demographic groups most affected include children younger than 10 years old and adults between 70 and 79 years of age. Expanding deer populations and warmer winters are among the contributing factors to the increased tick activity.
Climate studies indicate that blacklegged tick habitat could expand over 200 percent by the end of the century.
Dangerous Tick-Borne Diseases on the Rise
Dr. Suraj Saggar, chief of infectious disease at Holy Name Medical Center in Teaneck, New Jersey, expressed particular concern about one emerging threat.
“Powassan virus disease is arguably the most concerning emerging tick-borne infection,” Dr. Saggar warned.
Powassan virus carries a roughly 10-15 percent fatality rate. More than half of survivors experience lasting neurological deficits, making it one of the most dangerous tick-borne illnesses in the United States.
While Powassan virus presents severe risks, Lyme disease remains the most common tick-borne illness affecting Americans. The disease has seen dramatic regional increases, with Ohio experiencing a roughly 10-fold increase in cases over the past decade alone.
Understanding Transmission and Prevention
Dr. Saggar provided important information about how tick-borne diseases spread.
“The longer a tick is attached, the higher the risk of disease transmission — for Lyme disease, transmission generally requires at least 36 hours of attachment,” he explained.
This 36-hour window provides a critical opportunity for prevention. Prompt tick removal after outdoor activities can significantly reduce the risk of Lyme disease transmission.
Currently, no vaccines are available for tick-borne diseases in the United States. This makes personal prevention measures particularly important during peak tick season.
Important Prevention Recommendations
Health experts recommend several strategies to reduce tick bite risks. Tumble-drying clothing for 10 minutes can effectively kill ticks that may have attached to fabric during outdoor activities.
Thorough tick checks after spending time outdoors remain essential, particularly for children and older adults who face the highest rates of tick bite ER visits. Paying attention to areas where ticks commonly attach, including the scalp, behind ears, underarms, and groin area, can help identify ticks before disease transmission occurs.
Given that Lyme disease transmission generally requires at least 36 hours of tick attachment, daily tick checks provide an important window for prevention.
Regional Impact and Geographic Spread
The expansion of tick populations over the past three decades has transformed what was once primarily a Northeastern concern into a national public health issue. The Ohio River Valley region exemplifies this geographic shift.
Dr. Goldberg noted that the convergence of Northeastern and Upper Midwestern tick populations in the Ohio corridor has contributed to the dramatic increase in Lyme disease cases in that region.
The expansion continues as climate conditions create favorable environments for ticks in previously inhospitable areas. Scientists estimate that blacklegged tick habitat could expand over 200 percent by the end of the century, potentially exposing millions more Americans to tick-borne disease risks.
Frequently Asked Questions
How high are tick bite ER visits compared to normal levels?
In April 2026, tick bite-related ER visits reached approximately 71 per 100,000, compared to a historical seasonal average of roughly 30 per 100,000. This represents the highest seasonal level since 2017.
How long does a tick need to be attached to transmit Lyme disease?
According to Dr. Suraj Saggar, Lyme disease transmission generally requires at least 36 hours of tick attachment. Prompt tick removal after outdoor activities can significantly reduce transmission risk.
Which age groups are most affected by tick bites?
CDC data shows the highest rates of tick bite ER visits among children younger than 10 years old and adults aged 70-79.
Are there vaccines available for tick-borne diseases?
No vaccines are currently available for tick-borne diseases in the United States.
How can I kill ticks on my clothing?
Tumble-drying clothing for 10 minutes can effectively kill ticks that may have attached to fabric during outdoor activities.
What Happens Next
As tick season continues, health officials are urging Americans to remain vigilant about tick prevention and prompt removal. With approximately 476,000 Americans diagnosed and treated for Lyme disease annually, and cases increasing two- to threefold over the past 20 years, the public health impact of tick-borne diseases continues to grow.
The absence of available vaccines for tick-borne diseases in the United States means personal prevention remains the primary defense against infection. Medical experts recommend consistent tick checks, proper clothing treatment, and awareness of symptoms following potential tick exposure.
Americans spending time outdoors should be particularly aware of the expanded geographic range of disease-carrying ticks and the elevated risk levels indicated by the current surge in tick bite ER visits across most U.S. regions.
