Lyme Disease Case Reports Have Doubled in Past 15 Years

Most parents of past generations wouldn't think twice when their child was bitten by a tick — they'd likely just remove it and send their tot back out to play. But doctors today know that ticks can carry Lyme disease, the most common infection transmitted by ticks, fleas, or mosquitoes in the United States.

Now, the Centers for Disease Control and Prevention (CDC) say that more than twice as many cases of Lyme disease are reported today than 15 years ago.

In 1991, when doctors nationwide started reporting Lyme cases to the CDC, there were fewer than 10,000. Now, the CDC is informed of about 20,000 cases of the disease each year. And kids are commonly infected — 61% of the cases from 2003–2005 were among 5- to 14-year-olds.

Caused by the bacterium Borrelia burgdorferi, Lyme disease is transmitted to people by the black-legged (or deer) tick, mostly in June, July, and August. Though it's found throughout the country, nearly all (93%) of the cases reported in 2003–2005 were in 10 states:

• Connecticut
• Delaware
• Maryland
• Massachusetts
• Minnesota
• New Jersey
• New York
• Pennsylvania
• Rhode Island
• Wisconsin

So, why are there so many more cases now? Not only are more people likely contracting the disease, doctors are also identifying and reporting cases more often. At first, symptoms may include the telltale bull's-eye rash, called erythema migrans (though some never develop the rash at all), as well as flu-like symptoms such as:

• fatigue
• fever
• chills
• headache
• muscle aches
• swollen lymph nodes

When it goes undiagnosed and untreated, Lyme disease can gradually spread to multiple areas of the body, causing symptoms like joint pain and swelling, irregular heartbeat, tingling in the arms and legs, and memory and concentration problems.