July 26, 2017

Podcast: tick bite prevention

July 26, 2017

Podcast: tick bite prevention

Our Director of Research and Science, Dr. Mayla Hsu talks to us about tick bite prevention, and what you can do to protect yourself from tick-borne infections.



Transcript below:

Lindsy: Welcome everyone, I’m Lindsy Brophy, Digital Marketing & Social Media Manager at Global Lyme Alliance. I’m at Greenwich Public Library with Dr. Mayla Hsu, our Director of Research and Science, to talk about tick bite prevention, and what you can do to protect yourself from tick-borne infections. To start, I want to ask Mayla to tell us first why preventing tick bites is so important. We’ve all heard of Lyme disease, which is on the increase, and every year afflicts over 300,000 people in the US. But are there other diseases we should worry about also?

Mayla: Hi Lindsy, and thank you for hosting me today. You’re right, Lyme disease is a serious illness that is transmitted by bites of the blacklegged tick. Most people, if they get treated with antibiotics, get well. But at least 10-20% of them continue to have symptoms beyond six months, and even into years. Some of those symptoms, like debilitating fatigue, chronic pain, and neurological problems, can really derail normal life.

But aside from Lyme disease, ticks are responsible for spreading up to about 20 different illnesses worldwide. Here in the US, we are most worried about bacterial diseases like Lyme, anaplasmosis, and ehrlichiosis. Then there is Babesia infection, which causes babesiosis. It’s a parasite of red blood cells that’s in the same family as malaria. There is also Powassan virus, which causes a pretty serious neurological inflammatory disease that is fatal in 10-20% of people who get it. The first step to preventing all of these illnesses is, of course, avoiding tick bites. We can all take steps to do this.

Lindsy: I know that some tick bite prevention measures are pretty obvious: wear long pants and long-sleeved shirts that are light colored, so you can see ticks. Tuck pants into boots. Do tick checks when you come indoors. Take showers after being indoors.

Mayla: yes, that’s right. These are sort of low-tech steps that you can take. Research by Dr. Kirby Stafford, an entomologist at the Connecticut Agricultural Research Station tells us that most tick bites occur in our own yards. So it suggests that perhaps we relax our vigilance when we’re at home, not bothering to check for ticks or wear protective clothes when we are near home. That’s a mistake. But we are also home more often than we go for walks in the woods, so the probability of getting a tick on us is simply higher, close to home.

There are bug repellents that we can apply to our skin: anything with 25-30% DEET, which is sprayed onto the skin, picaridin at 20%, oil of lemon eucalyptus, and 20% IR3535. These are repellents which discourage ticks from getting on us.

But there are also products we can apply to our clothes that will actually kill the ticks. Remember, they are not insects, they are arachnids, closer to spiders and mites. So the products that kill them are called acaricides. Permethrin is a spray or wash that we put on our clothes, and it will kill any ticks that get on them. One word of caution is that permethrin, though very effective, is toxic for cats, and that’s a problem if you have a cat who rubs against your pant leg or sits on your lap.

Lindsy: If most tick bites actually occur in our back yards, then are there landscaping techniques we can use to reduce tick bites?

Mayla: Definitely the way we set up our homes and yards are important. We have to think about the tick life cycle when we think about this.

Lindsy: oh yes, why’s that?

Mayla: Ticks hatch from eggs as larvae. After one blood meal, they become nymphs. After a second blood meal, they become adults. When they’re larvae and nymphs, they tend to bite small mammals like mice, squirrels, chipmunks and also birds. But as adults, their behavior changes, and they ‘quest”, or seek hosts, higher up on taller grasses rather than low in leaf litter. That’s why adult ticks, not nymphs and larvae, are found on deer. And this is important, because the adult ticks mate while on deer, and then the fed females drop to the ground and lay between 2000-4000 eggs. If you have a fenced yard, you can’t prevent mice and small mammals from getting in. But you can keep the deer out, and all those eggs won’t be laid on your yard, hatching and producing larvae and nymphs. The mice might bring them in, but they won’t be hatching from your ground.

Lindsy: okay, but besides a fence, what else can you do to your yard?

Mayla: you can spray your yard, getting commercial pesticide companies to come apply acaricides. There are some natural products that can be used, but with any of these sprays, you have to remember that they may evaporate, they will wash away, and they will need re-applying.

Lindsy: and are there other ways to arrange your yard to reduce ticks?

Mayla: Ticks need humidity to live. It’s a big danger for them to dry out. So if you reduce bushes that create dark and humid microenvironments, then you can reduce the survival of ticks. The Japanese barberry is present in many New England areas, because it’s a pretty ornamental that many people like. However, it has been shown that removal of it really reduces the numbers of ticks on mice. In more southern states, the giant reed creates cooler and dark, humid spaces that promote mice and tick survival. Removing leaf litter, where larvae and nymphs are, helps. And also, installing 3-foot wide wood chip borders between leaf litter and lawns or walkways mean there is a physical barrier between where the people are and where the ticks are predominantly found. Swing sets or play sets should not, in fact, be in those shady edge areas of the yard, but instead, should be installed where it is hotter and drier. And try to keep the grass short. Ticks are often questing at the ends of those long strands.

Lindsy: I’ve heard of “tick tubes” that some people use in their yards. What are those?

Mayla: The major host of larvae and nymph ticks is the mouse, and mice build nests where they raise their pups. So it’s been tested whether mice will use permethrin-soaked cotton balls in their nests, and that will kill ticks in their nests and on them and their young.

Lindsy: And does it work?

Mayla: It does work in some settings, where the principal host is the mouse. But in some areas, there are not only mice, but there are squirrels, chipmunks and other small mammals who do not build nests like this, so there is no significant reduction in tick numbers. There have also been attempts to set up deer feeding stations so that as they feed, their heads rub against permethrin or other acaricides, and these have had some success. Deer reduction such as by hunting appears to be problematic in some towns, as there are always people – even those who have had Lyme disease – who oppose it. But it has been shown in a couple of islands, that when deer have been eliminated, the incidence of Lyme disease has gone way down.

Lindsy: So it sounds like there are many ways we can try to protect ourselves, ranging from taking care of our yards, managing ourselves, possible deer and mouse interventions, but are there any new experimental techniques in the works that might reduce tick bites or Lyme disease?

Mayla: Oh yes, there are a number of things being researched, such as vaccines for mice or deer, that might make them inhospitable to ticks or to the bacterium that causes Lyme disease. There are smaller studies of deer contraceptive vaccines that are supposed to control deer numbers, but I’m not sure if the data is in for those yet. For now and the forseeable future, what is called “Integrated Pest Management”, or a combined approach, that combines many of these techniques, is our best defense against getting Lyme disease and tick bites.

Lindsy: Are there any other points you might want to mention?

Mayla: Thinking about all of this really makes it obvious that we need more research. We need to figure out how to control this thing. We need a committed approach to tackling this problem. That means we need more government funding and a true investment to figuring this out, not only how to prevent tick bites, and how to manage land better, but how to diagnose and treat Lyme disease more effectively.

Lindsy: There’s certainly a lot to think about. Thank you for the informative discussion!

Mayla: Thank you.

Lindsy: So listeners, please let us know if you have any questions and we’ll be sure to address them in our next podcast. Thanks for listening to us today.

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