Tick-Killing Tip: Dry Then Wash, Brief Dryer Spin Could Do It

Tip #1 on www.tickencounter.org/ticksmart/tips (Courtesy of TickEncounter Resource Center)

Tip #1 on www.tickencounter.org/ticksmart/tips (Courtesy of TickEncounter Resource Center. Note the tiny black tick in center foreground.)

It sounds so odd, like being told, “Put on your shoes, and then your socks.” But indeed, one useful tip for killing the ticks that carry Lyme disease is to put the clothes you were wearing outside into the dryer for a few minutes before you wash them — the better to kill the ticks, you see.

How long exactly to dry them? Well, today’s Boston Globe features a delightful story about a Braintree teenager, Jacqueline Flynn, who set out to find out, and whose preliminary research suggests that ticks can be killed in just five minutes of drying at low heat.

That discovery by the 16-year-old Braintree High School student has won top local science prizes and has caught the attention of scientists at the Centers for Disease Control and Prevention, the nation’s massive health watchdog.

As part of its tick prevention recommendations, CDC literature urges tumbling tick-infected clothing in a dryer on high heat for at least an hour as one way to eliminate the bloodsucking arachnids. But the agency had not studied the method further…

“This could have significant implications for Lyme disease prevention,’’ said Christina Nelson, an epidemiologist at the CDC’s office in Fort Collins, Colo., who became intrigued by the teenager’s finding. “If it is true that five minutes in a dryer kills ticks vs. a full hour, that is a lot easier for people, and that could also spark further investigations.”

With tick season, and thus Lyme disease season, soon upon us, however, we wouldn’t want to draw half-cooked conclusions and under-dessicate any of the little buggers. So I checked in with tick expert Tom Mather of the University of Rhode Island and its TickEncounter Resource Center.

He confirmed that a fairly quick spin in the dryer can kill nymphal deer ticks that carry Lyme disease, as the TickEncounter Resource Center has been recommending:

Most ticks are VERY sensitive to dryness. The very first action to take after working in the yard is to strip clothing off and throw it in the dryer. Deer ticks are most susceptible, while American dog ticks, Lone Star ticks and other Amblyomma species are more robust. To be sure that each species achieves fatal crispiness, leave clothes in the dryer on high for 15 minutes.

In our study, gas dryers got hotter than electric dryers, so you might want to add 5 minutes if you own an electric dryer. Believe it or not, ticks were not killed by washing, even in hot water. Clothing just left in the hamper or on the floor may put the next person to touch it at risk. Dry first – then wash.

And Prof. Mather added more research details in an email:

We showed that nymphal blacklegged ticks [a.k.a. deer ticks] were the most sensitive to dessication (easiest to kill in dryer) of all tested, followed by adult deer ticks, nymphal Lone Star ticks, and then adult Lone Star ticks and Am. dog ticks. We found that gas dryers ran a little hotter and that as little as 5 minutes was sufficient to kill the deer ticks but that to kill all of the Lone Stars and dog ticks, 10 minutes was required. For good measure, 10 minutes in the electric dryer for all was recommended (but probably overkill). We had temperature records as well. Ours were field-collected ticks. We applaud Jacqueline’s innovation; her observation is consistent with our findings…

It’s never too early to start thinking about measures to prevent Lyme disease, which is now endemic across Massachusetts. Check out other helpful TickSmart tips here.

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  • jaie

    I put my jeans in the dryer for 20 mins. I took them out and found a live deer tick walking on them. So much for a “quick drier spin”

  • Annie

    I’ve heard this may also work on bedbugs. Any time I buy clothing at ANY thrift shop or consignment store, I empty the contents from the tightly knotted bag (that rides home in my trunk) directly into the empty dryer, turn it on HOT for a half hour and THEN wash the clothes. Oh ya, and the bag immediately goes outside to be recycled later that day as a dog-poop-pick-up receptacle. Let ‘em try to survive in THERE!!

  • Alex Davis

    Avoiding being bitten by the deer tick is important because it not only carries Lyme disease, which can cause crippling arthritis and brain damage, but it also carries four other known diseases including babesiosis and anaplasmosis, both of which can be fatal. The Lyme epidemic was caused by the deer epidemic. In 1930 there were 300,000 deer in the US. Today there are 30 million. The deer are the main source of the deer tick eggs, and it’s estimated that ticks from just one deer can produce up to a million tick eggs per season. These are spread around our yards and neighborhoods, and they develop into the immature poppy seed-sized ticks which cause most human infections. The adult egg-laying deer tick requires a sizeable mammal to feed on, and 95% feed on deer. They cannot feed on a mouse, for instance, although the immature non-egg-laying forms can. Without tick eggs, there are no ticks, and without ticks, there is no tick-borne illness. Since deer are thus key to the reproductive cycle of the tick, one can see why Lyme epidemics in places like Monhegan Island ME and Mumford Cove CT were ended by removing the deer.

    • Carol

      Hi Alex
      Yes these diseases can be fatal and there’s 2 more. One already here (B. myamotoi), and another on the way-Powassan virus. That being said, it is NOT the deer, it’s the white-footed mouse. Fertile ticks that drop from deer and other large mammals are DISEASE FREE! The tick gets the infections they carry from the mouse. The largest amount of disease has more to do with the diversity of animal species and poor open space. The larger the land mass, the more diverse the species present there. Disease presence is much less. Conversely, small wood lots with few animal species living there, as in suberbia, the more infected the ticks are. The chipmunk and a few voles are also carriers of these diseases. However, the mouse is the preferred carrier(reservoir). Even when deer are culled from a site (experiments have been done) there are,just has many ticks the next season (it’s,a two year cycle. Always advocate for open space and conservation. These places give us less disease. -Carol, Medical Lab Scientist

      • Alex Davis

        I’m afraid you missed the point. Ticks come from tick eggs. Without tick eggs there are no ticks. Without ticks there is no tick-borne disease. The main source of tick eggs is the deer, not the mouse. In fact not one tick egg comes from a mouse because the adult egg-laying deer tick cannot feed on a mouse. It requires a sizeable mammal and 95% feed on deer. This is why it has been shown that reducing the deer will reduce the tick population and the incidence of Lyme disease. There has been already demonstrated in Great Island MA, Mumford Cove CT and Monhegan Island ME. The deer population must be reduced and maintained at a low level which is harder to do in the vast mainland but obviously not impossible when people are motivated. Conversely, the massive rise in deer population here has resulted in a huge rise in ticks and Lyme disease. (As I noted before, there are four other diseases carried by the deer tick including the two you mentioned.) Your advocacy of open space is not a reasonable solution because as long as there are deer, there will be tick eggs, and as long as there are tick eggs there will be ticks and tick-borne-illness. Ticks coming from deer may be initially disease-free but they soon acquire the disease from mice and other animals. Deer readily migrate from open spaces to our yards, bringing all the tick eggs with them. We would have ended this epidemic long ago if it were not for the pro-deer lobby and the misinformation they propagate.