Map Aims to Help Health Officials Take a Bite out of Lyme Disease

After sizing up more than 5000 ticks, researchers have created a detailed map of the Eastern United States pinpointing where humans are at highest risk of contracting the disease. To develop the map, tick hunters dragged sheets of fabric through wooded, bushy areas over a four year period to snag infected blacklegged ticks – also known as deer ticks – that transmit the disease through their bite. About one in five collected were laden with Lyme.

The map shows people in the coastal Northeast, Mid-Atlantic and Upper Midwest regions are at the highest risk of contracting the disease. Those in the majority of the South are at low risk. “Transitional areas” where the disease is likely to spread, include the northern parts of Illinois, Indiana and Ohio, New England and the coastal areas of Virginia and North Carolina. The results were published in the February issue of the American Journal of Tropical Medicine and Hygiene (a Burness client).

Lead author Maria Diuk-Wasser said she hopes the map will be a useful tool for public health officials and doctors when assessing a Lyme disease diagnosis. "When a doctor sees a rash in the South, he shouldn't immediately be thinking it's Lyme disease," she told NPR. "And in areas where the ticks are expanding to, doctors should start thinking that Lyme disease is a possibility."

Lyme disease is one of the most rapidly emerging infectious diseases in North America, according to the U.S. Centers for Disease Control and Prevention. Its symptoms range from a simple rash and flu-like conditions all the way to arthritis and Bell’s palsy.

“The scientific research done to create this new risk map for Lyme disease is an example of what is needed in the U.S. today for a variety of diseases given its immense value in making clinical decisions and allocating scarce resources,” says James W. Kazura, MD, President of the American Society of Tropical Medicine and Hygiene, which publishes the journal, and director of the Center for Global Health and Diseases at Case Western Reserve University.

The CDC counted more than 30,000 confirmed or probable cases of Lyme disease in 2010, with more than 90 percent of those cases in 12 states.

For more information on the report, check out “New map pinpoints Lyme disease risk areas” from the AP, this blog on Scientific American and this video from WBUR’s CommonHealth.