Lyme Disease Cases Continue to Rise as Tick Season Returns

As warmer weather approaches, health officials are reminding people to take precautions against tick bites as cases of Lyme disease continue to increase across the United States.

According to the Centers for Disease Control and Prevention (CDC), more than 89,000 cases of Lyme disease were reported in 2023, the most recent year with full data available. However, experts believe the real number is much higher. The CDC estimates that about 476,000 people are diagnosed and treated for Lyme disease each year in the U.S.

Lyme disease is caused by the bacterium Borrelia burgdorferi and spreads to humans through the bite of infected blacklegged ticks, often called deer ticks. While the illness has long been associated with certain regions, experts say it is spreading geographically, with cases now reported in more areas of the country.

The highest numbers of infections are still found in the Northeast, mid-Atlantic, and upper Midwest regions, where tick populations are well established.

One challenge with Lyme disease is that its symptoms can resemble those of other conditions. The illness can sometimes be mistaken for fibromyalgia, chronic fatigue syndrome, or other health problems, making it difficult to diagnose in some cases.

Many infections begin with a skin rash known as erythema migrans. The rash often appears as a red, expanding patch and may resemble a bull’s-eye, though not everyone develops this classic pattern.

If Lyme disease is not treated early, it can lead to more serious health issues. These may include arthritis, particularly in large joints such as the knees, as well as neurological problems like facial paralysis, meningitis, or nerve pain. In some cases, the infection can affect the heart, causing a condition known as Lyme carditis. Less commonly, complications can involve the eyes or other parts of the body.

Although infections can occur at any time of year, most cases happen between late spring and early fall, when ticks are most active, and people spend more time outdoors.

Currently, no Lyme disease vaccine is available for public use. A previous vaccine was discontinued years ago, though researchers continue to study potential new options.

Health experts stress that early antibiotic treatment is highly effective and usually prevents serious complications.

Because of that, prevention remains the most important defense. People spending time in wooded, grassy, or brushy areas should wear long sleeves and long pants, tuck pant legs into socks, and use EPA-registered insect repellents containing ingredients such as DEET, picaridin, or oil of lemon eucalyptus. Clothing and outdoor gear can also be treated with permethrin to repel ticks.

Officials also remind the public that Lyme disease is not contagious and cannot spread from person to person.

With tick season returning, experts say taking simple precautions outdoors can greatly reduce the risk of infection while still allowing people to enjoy the warmer months ahead.