An army of ticks is sending more Marylanders to the ER

It may not feel quite like summer yet, but one seasonal pest is already out for blood.

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.

Local doctors and public health officials are preparing for more cases of Lyme disease and other tick-borne illnesses, including one that can cause a potentially life-threatening allergic reaction to red meat.

It’s shaping up to be “a big year for ticks and tick-borne diseases,” said Thomas Hart, an infectious disease microbiologist at the Johns Hopkins University’s Lyme and Tickborne Diseases Research and Education Institute.

Hart said the trend has been upward for the past two decades.

Climate change and rising temperatures have expanded the tick habitat and population. And even in especially cold and snowy winters like the one we just had, ticks can use the snow as something of a protective igloo.

Lyme disease the top threat

The most common disease associated with ticks is Lyme disease, and there were more than 89,000 cases reported to the U.S. Centers for Disease Control and Prevention in 2023, the latest year available.

Hopkins experts said in a news conference Tuesday that the number is likely far higher, as cases are often underreported and misdiagnosed due to vague symptoms.

Maryland had 2,463 reported Lyme disease cases in 2023. The illness is transmitted by deer ticks, also known as black-legged ticks, which are common in the state. That figure exceeded 3,000 in 2024, according to the Maryland Department of Health. Cases have almost tripled since 2020.

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.

It’s important to remove a tick and call a doctor if it has been attached for more than 36 hours — the time it takes to transmit disease — or if you have been in a wooded area and develop symptoms.

Doctors in Maryland are likely familiar with tick-borne illnesses and can treat them without an emergency room visit, said Dr. Ibukunolupo Oni, an infectious disease specialist at Greater Baltimore Medical Center in Towson.

Treatment usually involves a course of antibiotics to wipe out the bacteria. Some people need an extended course for persistent symptoms.

Oni said some people can have more lasting issues, such as joint inflammation and fatigue, commonly referred to as post-treatment Lyme syndrome. It’s still not fully understood and can be persistent, though it often resolves in time.

“We can’t tell people not to go outdoors; try your best to prevent infection,” she said. “We’d rather you not have an infection if you can help it.”

Don’t forget about other diseases

Oni and others said ticks can spread other diseases, such as babesiosis and Rocky Mountain spotted fever, though Maryland reports far fewer cases compared to Lyme.

Many of the diseases begin with similar flu-like symptoms and can be hard to differentiate from other conditions, said Dr. Nicole Baumgarth, a Hopkins professor of immunology and infectious diseases and the director of the Lyme and Tickborne Diseases Research and Education Institute.

She said better diagnostic tools are needed, and doctors must be aware of emerging conditions.

In more areas of the country, that includes a condition that can resemble an allergy: alpha-gal syndrome.

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.

“We’re seeing it more and more when we go out and collect ticks,” Baumgarth said.

She said there are no vaccines against any of these tick-borne diseases, though one for Lyme has shown promise in advanced studies. It could be available in a year, though the Hopkins experts said it likely wouldn’t have wide uptake because it could necessitate multiple shots.

Ways to stay safe

The experts agree that prevention is the best strategy at the moment.

The state health department has already begun its annual effort to raise awareness about tick-borne diseases, encouraging Marylanders to take precautions. People should enjoy the warmer weather and explore the outdoors, according to Dr. Meena Seshamani, Maryland’s health secretary.

But she said in a statement that her department wants Marylanders “to safeguard their health by knowing about ticks and the ways to protect people and pets against the diseases ticks carry.”

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

• Wear light-colored clothing that makes it easier to spot ticks

• Treat your clothes with permethrin or purchase permethrin-treated clothing and gear

• Shower as soon as possible after returning indoors

• Dry your clothes on high heat for 10 minutes at home to kill any ticks

• Perform a tick check on yourself, children and pets after being outside