With Lyme Disease on the Rise, New CDC Study Under Way

Despite the recent snow, tick season has begun.

"Oh yeah, the ticks are coming in," said Dr. Kirby Stafford, chief scientist of the Department of Entomology at the Connecticut Agricultural Experiment Station in New Haven. "They are out. Once temperatures hit even 40, the adult ticks will start moving."

Though the winter was harsh this year Stafford expects it did not deplete tick populations.

"It's hard to judge but I expect all that nice snow cover, since it acts as an insulating blanket, didn't hurt them at all," Stafford explained.

Though he's only tested a few ticks for 2011, Stafford expects about half that are sent into the lab will test positive for Lyme disease.

For 2010, numbers have not yet been released. But in 2009, more than 4,000 ticks feeding on humans were submitted to the lab for identification. Of those, 1,802 were tested and about 37 percent were found to be carrying the disease.

"It's going up," Stafford said. "Part of the increase has to do with increased reporting and surveillance but trends are evident that it's been going up."

Lyme disease was first identified in Connecticut in 1975 and continues to be a public health concern. Surveillance maintained by the state Department of Public Health has shown that Connecticut has the highest number of cases relative to the population of any state.

The rising incidence of the disease is due to a variety of factors, according to the DPH, including: 

• Increased tick abundance
• Overabundant deer population
• Increased recognition of the disease
• Establishment of more residences in wooded areas
• Increased potential for contact with ticks

This year, the DPH is participating in a new study to determine if tickborne diseases can be prevented with a single, targeted pesticide application to yards.

The study is in partnership with Yale Public Health and the U.S. Centers for Disease Control and Prevention. It is being conducted in Connecticut, Maryland and New York. Local health departments are looking for volunteers to test the pesticide.

"There are areas in the three states where there's a high incidence of Lyme," said Monica Wheeler of the Westport Weston Health District. "So, the whole idea is to try and see if one application of a pesticide actually affects the Lyme disease incidents."

Typically, multiple applications of pesticides are used on area lawns to control ticks but the study is going to determine if just one application will suffice, Wheeler said.

Given the widespread use of pesticides to control ticks, the CDC says "it is important to know to what degree pesticide use actually prevents human illness, and if so, how to minimize the amount used," according to CDC study coordinator Alison Hinckley.

The CDC is funding the study and has selected seven Fairfield County towns to test the pesticide application: Bethel, New Fairfield, Newtown, Ridgefield, Weston, Westport and Wilton. Those towns were selected due to having high incidence of Lyme disease, and available personnel at local health departments.

Pesticide use is already a recommendation for prevention of Lyme disease, says the CDC.  "The results of this study, however, could argue for more targeted use of these products," Hinckley said.

Aside from pesticides, Dr. Stafford is researching natural products that are also effective in controlling ticks. Though the results of his research will not be available for at least a year, garlic and rosemary oil are showing promise as are oils used in fragrances and cosmetics.

In the meantime, the traditional approaches of pesticide use and insect repellent will work, he said. Ticks found on humans or dogs can be sent in to the local health departments for testing, Stafford added.

Anyone interested in participating in the CDC study can contact 888-668-1856, email betickfree@yale.edu or visit betickfree.com for more information.