Cases of Lyme disease continue to rise sharply, according to the Centers for Disease Control and Prevention (CDC).
Over 89,000 cases were reported in 2023 (the most recent fully detailed year available), but experts estimate that around 476,000 people are actually diagnosed in the U.S..
The illness, caused by the bacterium Borrelia burgdorferi and transmitted through bites from infected blacklegged ticks (also called deer ticks), is expanding geographically across the United States and in many parts of the world. The highest numbers of cases still occur in the Northeast, mid-Atlantic, and upper Midwest regions.
Lyme disease can mimic other conditions like fibromyalgia, chronic fatigue syndrome, or other illnesses, making it tricky to identify.
Infections can happen year-round, but the majority of cases occur from late spring through early fall, peaking in summer.
The disease often begins with a characteristic skin rash called erythema migrans (a red, expanding rash that may look like a bull's-eye, though not always). If untreated, it can spread to cause more serious issues, including arthritis (especially in large joints), neurological problems (such as facial palsy, meningitis, or nerve pain), heart involvement (like carditis), and, less commonly, eye or other complications.
No Lyme disease vaccine is currently available for public use. An earlier vaccine was discontinued. Early treatment is highly effective and usually prevents severe complications.
Prevention remains key. Wear long-sleeved shirts and long pants, tucking pants into socks and shirts into pants when in wooded, brushy, or grassy areas. Use EPA-registered insect repellents (such as those containing DEET, picaridin, or oil of lemon eucalyptus) on skin and clothing. Treat gear and clothing with permethrin.
Lyme disease is not contagious from person to person.
