This year’s crop of Rocky Mountain wood ticks will soon be looking to catch a ride and a free meal on anyone spending time enjoying the woods surrounding the Bitterroot Valley.
A new study released this week by researchers at Rocky Mountain Laboratories offers one more reason why anyone venturing into the outdoors should do what they can to keep the tiny, blood-sucking arachnoids at bay.
Over the course of a five-year period, RML’s lead researcher on the project, staff scientist Brandi Williamson, tested 921 ticks captured by herself, fellow researchers, forest workers or hikers on both sides of the Bitterroot Valley.
Using the lab’s RNA-sequencing technology, Williamson found that 6.6 percent of the ticks tested carried the virus that causes the debilitating Colorado tick fever virus. At one of the Bitterroot’s most popular trailheads on the west side, about 20 percent of the ticks researchers captured tested positive for the virus.
“We found that there were a few hotspots,” Williamson said. “Some happen to coincide with some of the more popular areas for recreation, including Larry Creek, Blodgett and Mill Creek.”
The highest rate of infection was found at Blodgett where one in five of the ticks sampled over the period carried the virus that causes Colorado tick fever.
“We did get a good sample of ticks from Blodgett,” Williamson said. “The main take away for people is they should do all they can to avoid being bitten by a tick.”
The same species of tick Williamson tested also carries the more virulent Rocky Mountain spotted fever, which can be deadly if not treated. In the Bitterroot Valley, about 1 percent of ticks are infected with that disease.
While Colorado tick fever won’t kill a person, it will certainly make them feel miserable.
“I’ve known several people who have had it and they’ve been pretty sick,” said retired RML researcher Tom Schwan, who participated in the study. “We think it’s probably underreported. This virus is widespread in the Bitterroot and beyond.”
Between 2008 and 2012, the Montana Health and Human Services Epidemiology section reported an average of one case of Colorado tick fever per year in Montana. Three of the reported cases were in Missoula County. Ravalli County had no reported cases in the same time period.
“We believe these numbers are a gross underrepresentation of the actual CTF cases within the state, most specifically the valley,” the study said. “Many cases of this disease are likely underreported or undiagnosed.”
Symptoms of Colorado tick fever often begin three to six days after a tick bite. It typically starts with a sudden fever that continues for about three days and then comes back for a few more days after a one- to three-day break. Other symptoms include general weakness, headache behind the eyes, muscle aches, as well as nausea and vomiting.
Unlike the more deadly Rocky Mountain spotted fever, there is no treatment for Colorado tick fever.
The virus isn’t new in the Bitterroot Valley.
In the 1960s, well-known RML scientists Willy Burgdorfer and Carl Eklund completed a study similar to Williamson’s that used animals to test for the virus. Results from that earlier study were similar to what Williamson found.
Once the weather finally warms, ticks will reappear on both sides of the valley.
The two researchers said there are several things people can do to lower the chances of an infectious tick bite.
Ticks have eight legs that are tipped with a tiny grappling-like hook they use to attach to any mammal that happens by.
It’s easier to spot a tick that’s hitchhiked a ride if you’re wearing light-colored clothing. While it might not be stylish, Williamson said it’s also a good idea to tuck your pant legs into your socks to keep ticks from crawling up your bare leg.
Over the last few years of collecting ticks, Williamson said they seem to like hanging out on vegetation that’s about hip high.
“Try to avoid brushing up against grasses and bushes if possible,” she said.
Over-the-counter insect repellents containing DEET can also help keep ticks at bay.
When you find a tick out the woods, Schwan said the best thing you can do is just knock it off your body. While still out in the woods, it’s a good idea to have someone take a look at your back on occasion to ensure that one isn’t making its way toward your hairline.
When you get home, either wash your clothes or throw them in a hot dryer and then take another look at your body to ensure you haven’t picked up an unwanted visitor.
If you do happen to spot a tick that’s had enough time to attach itself, the researchers said the best way to remove it is to take a pair of tweezers and pull the tick off slowly. The tweezers should be right on the skin and as close to the tick’s head as possible.
“You don’t want to squeeze it,” Schwan said. “You want to get as close to the mouth parts as you can and then go slow and steady and pull it up and away.”
A lot of the infectious agents carried by the tick are found in the salivary glands, which means those can be transferred rather quickly.
“It’s best to get a tick removed quickly,” Schwan said. “The sooner the better … If you end up with a fever and you’ve been bitten by a tick, it’s best to assume the worst and go see a doctor.”