Number of U.S. Lyme disease cases much higher than expected

“A tremendous public health problem”

Today's News Approximately 300,000 are diagnosed with Lyme disease each year, according to a newly released estimate by the Centers for Disease Control and Prevention (CDC). The estimate is based on medical claim, a survey of clinical laboratories and a survey of the general public.

The new figure suggests that the total number of people diagnosed with Lyme disease is roughly 10 times higher than the yearly reported number, making it the most commonly reported tick-borne illness in the United States.

Cause and symptoms

Lyme disease is caused by the bacterium Borrelia burgdorferi and is transmitted to humans through the bite of infected blacklegged ticks. Typical symptoms include fever, headache, fatigue, and a characteristic skin rash called erythema migrans. If left untreated, infection can spread to joints, the heart, and the nervous system.

Paul Mead, M.D., M.P.H, chief of epidemiology and surveillance for the CDC’s Lyme disease program, says the estimate “confirms that Lyme disease is a tremendous public health problem in the United States, and clearly highlights the urgent need for prevention.”

Efforts are underway at the CDC and by other researchers to identify novel methods to kill ticks and prevent illness in people.

A community-wide approach needed

“We know people can prevent tick bites through steps like using repellents and tick checks. Although these measures are effective, they aren’t fail-proof and people don’t always use them,” said Lyle R. Petersen, M.D., M.P.H, director of CDC’s Division of Vector-Borne Diseases. “We need to move to a broader approach to tick reduction, involving entire communities, to combat this public health problem.”

This community approach would involve homeowners trying to kill ticks in their own yards, and communities addressing a variety of issues. These issues include rodents that carry the Lyme disease bacteria, deer that play a key role in the ticks’ lifecycle, suburban planning, and the interaction between deer, rodents, ticks, and humans. All must be addressed to effectively fight Lyme disease.

Are you in a danger zone?

Most Lyme disease cases reported to CDC through national surveillance are concentrated heavily in the Northeast and upper Midwest, with 96 percent of cases in 13 states.