Maryland Emergency Rooms Hit Record Tick Bite Surge

Record-Breaking Emergency Visits

Across the country, emergency department visits for tick bites are up more than 25% from last year, according to federal data. Maryland and other northeastern states are looking like ground zero. Emergency room visits in Maryland from tick bites have reached an all-time high because of climate change and urbanization. The Northeast bore the highest number of emergency visits from tick bites of any other region in the U.S. in May, with 283 emergency visits per every 100,000 people — up more than 70 since the same month in 2024, according to the CDC.

That figure exceeded 3,000 in 2024, according to the Maryland Department of Health. Cases have almost tripled since 2020. The surge isn't just numbers on a dashboard — it represents families rushing to emergency rooms, worried parents examining children after outdoor activities, and healthcare workers dealing with an unprecedented influx of tiny but potentially dangerous bites.

Nicole Baumgarth, an immunologist at the Johns Hopkins Bloomberg School of Public Health and leads the Lyme and Tickborne Diseases Research and Education Institute , warns that "It seems that we're in for a very bad year. And of course, these numbers are only the tip of an iceberg."

Climate Change Fuels the Crisis

Public health experts blame the increase in ticks on milder winters due to climate change, which allows them to survive for longer. "Even when there are colder winters, so for example, on the East Coast last year, the increased snowfall that comes along with that can provide a more insulated cover which ticks can stay warm, sort of acting like an igloo," said infectious disease microbiologist Thomas Hart, who studies Lyme disease bacteria.

A warming climate extends the period of time that ticks reproduce during the warmer months, and expands the territory in which they are able to live. Ticks can now live in more northern areas than before, Baumgarth said. Pastula speculated that warmer temperatures in March across the country have driven the increase in tick bites. "If it warmed up earlier," he told Healio, "then the ticks came out earlier, and maybe that's what we're seeing. I can't say that's the 100% cause of this increase, but I'm suspicious of that." In fact, 192 U.S. cities found that average temperatures in March were 5.8°F above normal, according to Climate Central, an independent nonprofit that reports on the impacts of climate change.

Humans are also increasingly coming into contact with areas that were once wooded, according to Norris. "You look at a map of Columbia, and its humans everywhere with little strips of green space," Norris said. This urban sprawl creates perfect conditions for human-tick encounters in backyards, parks, and recreational areas.

Dangerous Diseases on the Rise

Hopkins Medicine reports up to half of deer ticks in the state carry Lyme bacteria, potentially explaining the higher risk in Maryland and its neighbors to the north. Lyme causes fatigue, fever, aches and sometimes — though not always — a bull's-eye rash. If the disease is left untreated, there can be complications affecting the heart, joints and nervous system.

But Lyme isn't the only concern. It's spread by lone star ticks, which are also common in Maryland, and can cause an allergic reaction to red meat, including hives, stomach issues and potentially life-threatening anaphylaxis. Health officials are also increasingly concerned about the spread of the aggressive lone star tick, which is linked to a mysterious meat allergy and whose larvae travel in what are colloquially called "tick bombs." The tick is identifiable by the white starlike splotch on the backs of adult females, and the larvae hunt in packs — hence, the tick bomb moniker. Scientists are unsure why some people bitten by the tick develop a potentially life-threatening allergy to the red meat protein alpha-gal and others don't, or if the allergies were triggered by something other than the tick bite.

Lyme disease is the only tick-borne illness that a tick does not transmit immediately upon biting. For "whatever evolutionary reason," Norris said, you have 36 to 40 hours before Lyme disease transmission occurs, which makes catching the tick early all the more important. When diagnosed early, antibiotics can resolve more than 90% of Lyme symptoms.

Protection Strategies That Work

Officials say ticks are commonly found in leaf piles, weeds, tall grass, shrubs and woods. If you'll be spending time in such areas, you should: • Use EPA-approved insect repellents, such as DEET, picaridin or IR3535 · • Wear long sleeves and pants tucked into socks or boots After outdoor activities, individuals should check clothing, skin, and pets for ticks and shower with hot water within two hours to reduce Lyme risk.