The number of black-legged ticks, also known as deer ticks, that carry Lyme diseaseincreased to 31 percent statewide in 2015, a six percentage-point increase from previous years, according to the Connecticut Agricultural Experiment Station.
In addition, there are two additional diseases carried by deer ticks, though at lower rates: babesiosis, which is a malaria-like disease, and anaplasmosis, which can be treated with the same antibiotics that are used to treat Lyme disease.
“People should be very careful when they are having outdoor activities,” said Dr. Goudarz Molaei, director of the ag station’s tick-testing program. “We would encourage people to be extremely cautious.”
Molaei said the warmer winter weather is contributing to the increase in ticks. “Even today, we had tick submission to our lab,” Molaei said Tuesday.
Among other factors are that “the tick’s ecosystems have changed,” Molaei said. “We have caused substantial disruptions in the environment.” This has caused an increase in the population of deer, “which provide ample opportunity for ticks to get engorged … more than we can see in our recent history.”
In New Haven County, 34 percent of ticks collected by the ag station tested positive for Borrelia burgdorferi, the Lyme disease bacteria; 11.4 percent for babesia microti; and 5 percent for Anaplasma phagocytophilum.
In Litchfield County, the rates were 39 percent, 9.9 percent and 6.6 percent, respectively, while in Middlesex County, the rates were 31.5 percent, 8.9 percent and 1.3 percent for the three pathogens.
Each year, the Connecticut Agricultural Experiment Station tests 3,000 ticks collected from across the state. It has tested for Lyme disease since 1990, and added the other two diseases last year. However, there has been a research project in Redding sponsored by the Centers for Disease Control and Prevention, and Molaei said that “particularly the babeosis increase is quite obvious.”
Molaei said babeosis is treated with quinine-based drugs, derivatives of chloroquine, that are used to treat malaria. He said a single tick can transmit more than one disease, making treatment more difficult.
Molaei recommended wearing long pants and long sleeves and light-colored clothing in order to detect ticks more easily. He recommended a spray including DEET on exposed skin to ward off the ticks, and to avoid outdoor activities during hot weather.
He said insecticides based on pyrethoids can be sprayed on clothing and may remain effective for up to three washings. However, washing clothes will not kill ticks, Molaei said, adding that clothing that might carry ticks needs to be run through a clothes dryer for at least a half hour to kill the insects.
There are an estimated 300,000 cases of Lyme disease nationwide each year, according to the CDC. Between 2010 and 2014, 13,983 cases of Lyme disease, 659 cases of babesiosis, and 286 cases of anaplasmosis were reported in Connecticut, according to the agricultural experiment station.