Tick research study nets mixed results

MILLBROOK — Felicia Keesing of Bard College and Rick Ostfeld, a researcher at the Cary institute of Ecosystem Studies in Millbrook, held a webinar Wednesday, May 4, to talk about findings of a six-year study on the correlation of tick-borne illness and tick population.

Ostfeld said tick-borne illnesses have been on the rise. Lyme, anaplasmosis and babesiosis are the three main tick-borne illnesses, and it is estimated only 10% of cases are actually reported to the federal Centers for Disease Control out of an approximated 400,000 to 500,000 yearly. The geographical location of ticks has also been expanding throughout New England and the Great Lakes area.

There are three main tools for dealing with tick-borne illness: prevention, diagnosis and treatment. According to Ostfeld, diagnosis and treatment still use decades-old technology, and while there was a vaccine in place for Lyme disease in the early 2000s, it has not been in use since. The goal of the tick project was to discover if decreasing the tick population would decrease the spread of tick-borne diseases within neighborhoods.

Biologist Keesing is a co-director of the tick project, a study led by the Cary Institute. The project selected 24 neighborhoods in Dutchess County, and split them into four groups. The tick project got about 25-45% group participation in each neighborhood from their residents.

The project utilized two tick-intervention tools: a commercialized spray of the microscopic fungus Metarhizium Brunneum named Met52, and an item known as the TCS Bait Box, in which small animals like chipmunks climb inside for food and are coated with a chemical that kills any ticks they encounter. Both products are available for commercial use.

Each neighborhood was then given a different combination of the two tick intervention techniques. One was given both, one was given neither and the final two were given one.

Neither the residents nor researchers collecting data in these areas were told which neighborhood had which.

In the neighborhoods where the bait boxes were used, tick populations decreased by about 50%.

There was a decrease with Met52 as well, but it was negligible in comparison. This was both in forested areas, and on residential lawns. It was concluded that the bait boxes were most effective.

What about the effect on tick-borne illnesses? Despite the decrease in tick population, residents of the neighborhoods with tick deterrents reported the same amount of tick borne illnesses as well as tick encounters.

However, pets and local forest animals had a decrease in illnesses.

Ostfeld reminded the audience that remedies such as tick repellents on skin and clothing have proven to be effective in preventing tick bites.

For more information, go to www.tickproject.org.