Ticks on rise with warmer weather, warns state entomologist

Deer tick populations are growing due to a warm winter in Connecticut. Residents must be cautious to avoid Lyme disease, as well as the deadly Powassan virus. (Photo courtesy to http://insightpestsolutions.com/)

A warm winter means a surge in adult deer tick populations this spring and an increased risk for tick-borne diseases, said State Entomologist Kirby Stafford III.

“Our mild winter means we’ve seen an exponential high level of (tick) activity,” Kirby said. “People need to be aware that the deer tick is the vector (for several diseases).”

While Lyme disease is one of the most well known diseases carried by deer ticks, the steadily growing, possibly deadly Powassan virus is currently being researched by CAES, Stafford said. While the virus was originally discovered in Canada in 1958, a new strain called Lineage 2 has been discovered in deer ticks, Stafford said.

A very small percentage of all deer ticks carry this strain of Powassan, Stafford said. Between 2008 and 2012, several ticks carrying the virus were discovered in Branford and Bridgeport, according to a study conducted by CAES. However, there has been only one suspected case in Connecticut so far, Stafford said.

The disease, unlike Lyme, which needs the tick to remain on for at least 36 hours, requires the tick to feed for about 15 minutes in order for the virus to transmit, Stafford said, because the pathogen is located in the tick’s salivary glands instead of in its gut. The incubation period can last from a week to a month, and include symptoms such as weakness, paralysis and vomiting.

The virus attacks the nervous system and can cause meningitis and encephalitis (swelling of the brain and brain lining), Stafford said, and can cause permanent neurological damage. Ten percent of all cases are fatal, Stafford said. There is no current treatment or cure.

“It’s a serious virus, but we’re not seeing that many cases so far,” Stafford said. “The infection rates in the ticks aren’t very high.”

The amount of cases, though low, are currently increasing, especially in the Midwest and the New York state area, Stafford said, though less than 20 cases have been reported nationally since 2013.

“It has been showing a slow but steady increase,” Stafford said. “It is possible we’ll see more cases moving forward.”

Research is underway, though the total number of cases is still in debate, because some people do not display symptoms at all, Stafford said. Though the disease is serious, cases are rare, Stafford said.

However, 30 to 40 percent of all deer ticks in Connecticut carry Lyme disease, Stafford said, which means that precautions must be taken to avoid contact.

“Do tick checks,” Stafford said. “(They’re) critically important in preventing disease.”

Seventy-five percent of tick disease cases result from ticks picked up from activities around the home, Stafford said, including gardening and yardwork. Adult deer tick populations peak in the spring and fall, with nymphs (juveniles) peaking in the summer, Stafford said. Nymphs tend to have a higher infection rate for Lyme disease, Stafford said.

“If you find a tick on you, use fine-tipped forcep to remove it,” Stafford said. “(Nymphs) are much smaller, they’re easy to miss.”

Ticks can be repelled using sprays that include DEET, Stafford said, as well as repellents made to be applied to clothing. Spraying backyard areas and clearing away brush and areas where ticks and their vectors, wild mice, can reside, will also help reduce tick populations, Stafford said.

With an increase of tick populations, Stafford said that it’s critical for people to remain informed about the diseases deer ticks can carry.

“We’re dealing with multiple pathogens, and we need people to be aware,” Stafford said.


Marlese Lessing is a staff writer for The Daily Campus. She can be reached via email at marlese.lessing@uconn.edu. She tweets @marlese_lessing.