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The Dose Transcript for May 17, 2023

Host: Dr. Brian Goldman

STORIES FROM THIS EPISODE

BRIAN GOLDMAN: Hi, I'm Dr. Brian Goldman. Welcome to The Dose. Tick populations are expanding across Canada and not just in rural areas or green spaces. There are ticks in your backyard, even if you live in the city. Some of those ticks spread diseases like Lyme. So this week we're asking, what do I need to know about ticks? Hi, Isaac. Welcome back to The Dose.

ISAAC BOGOCH: Hey, Brian, great to chat. Thanks to having me back.

BRIAN GOLDMAN: Have you ever been bitten by a tick before?

ISAAC BOGOCH: Oh, yeah. Lots.

BRIAN GOLDMAN: Lots. So what do you do that gets you bitten by ticks?

ISAAC BOGOCH: Well, I spend as much of my summer outdoors and a lot of my summer outdoors, as, you know, hiking, canoeing, hanging out in areas where there's ticks. And a lot of that was spent in northern Ontario, could do trips and whatnot growing up. But, you know, tick bites are a part of being outdoors. And in all fairness, you know, I know we're going to talk about Lyme and we're going to talk about ticks and we're going to talk about tick transmitted illnesses. But I think the take home point is we are blessed with by living in one of the best countries on the planet and blessed with incredible, endless nature. And I hope Canadians go and enjoy that. And, you know, ticks are certainly a tiny component of this that we can easily manage to get around. So, yeah, we've got to be aware of them. We've got to know how to manage them, but we should all be outside enjoying the beauty that Canada is, especially in the summer.

BRIAN GOLDMAN: Well put, Isaac, before we begin, can you give us a Hi, my name is and tell us what you do and where you do it. Just ad lib.

ISAAC BOGOCH: Absolutely. I'm Isaac Bogoch I'm an Infectious Diseases Physician and Scientist. I'm based out of the Toronto General Hospital.

BRIAN GOLDMAN: Okay, here we go. We'll get to Lyme disease specifically in a moment. But I'm just curious. You're the expert. What other diseases do ticks transmit or.

ISAAC BOGOCH: Well, ticks transmit a myriad of illnesses specifically in Canada, there's, you know, certain types of ticks and certain types of ticks transmit certain types of infections. But in general, ticks transmit bacterial infections such as Lyme. And then less common bacterial infections that we see include something called Anaplasmosis, something called Rocky Mountain spotted fever, another bacteria called tularemia. Ticks can transmit parasitic infections, and the classic parasitic infection, at least in North America, is as one called babesiosis. And then lastly, ticks can transmit viruses as well. And there's a rare virus that's a tick transmitted called powassan virus.

BRIAN GOLDMAN: But the one we hear about most often is Lyme. Is it because the incidence of Lyme disease is greater than all the other pathogens that you just mentioned?

ISAAC BOGOCH: Yeah, 100%. Lyme, especially in Canada, is by far the most important tick transmitted illness because it is by far the most common tick transmitted illness. Listen, we are going to see more of those other ones as we have more and more ticks. And as ticks survive the winter and as climate change influences the spread of pathogens globally, we will see more infections that many people might not have heard of, like Babesiosis and Anaplasmosis. We will see more of those in Canada, but if we timestamp to summer 2023, we're going to see more lives than any of those other ones combined by far.

BRIAN GOLDMAN: Are there places across the country with more ticks that carry Lyme than other places?

ISAAC BOGOCH: There absolutely are. There are certainly are hot spots in Canada for Lyme and for ticks. Southern Ontario is certainly a hot spot. Many, many parts of Nova Scotia, especially where it abuts New Brunswick, are hot spots. There's parts of southern Manitoba as well as and where southern Manitoba borders northern Ontario. There's Lyme pockets there for sure. And of course, in British Columbia as well, the southern part of British Columbia, those are hot spots. Now, of course, there's Lyme and ticks outside of those zones. But with the ticks surveillance and the Lyme surveillance that we have in Canada, it appears that those areas, which of course are heavily populated areas, have a greater incidence of of Lyme disease.

BRIAN GOLDMAN: So a higher population. Are there climate change issues that could be playing a role in the increased incidence?

ISAAC BOGOCH: Oh, I think that's absolutely correct. And, you know, if you look at surveillance for Lyme in Canada over years, you know, this is something that happens in the background over years and years and years. You're seeing the northern migration of of ticks at Lyme as well, and of course, other tick transmitted illnesses. And as ticks can survive the winters in greater frequency and as ticks and spread to other other more northern climates because they can survive in those northern climates, you're going to see more tick transmitted illnesses. So even if you look at human cases of Lyme in Canada year over year, there's certainly an upward trend. When you go back and monitor this over the past ten or 20 years, we're seeing more and more Lyme year after year in Canada. There's an upward trend for sure.

BRIAN GOLDMAN: You mentioned that you go hiking, you go canoeing in the summer. And, you know, clearly if you're going into wooded areas, you're at risk of getting bitten by ticks. But I've heard recently that golfers are also finding that they're bitten by ticks as well. Is that a new trend?

ISAAC BOGOCH: I was going to make a terrible joke and it depends on how good a golfer you are because ticks really like a particular environment. So, like, if you're staying on the fairway, you know, ticks are not going to be hanging out in short grass all that often. Ticks really love wooded areas and tall grass. So if your ball is in the rough and you're spending a lot of time in the woods hacking away, yeah, I'm sure you're probably in in tick territory. But, you know, obviously not to make light of a situation, but, you know, there are certain geographic areas where we see more light. But if you want to get more picky there, there are particular environments and it really is wooded areas and grassy areas, particularly taller grass. Those are tick habitats. And when we come into contact with those tick habitats, we can obviously get exposed to ticks and get tick bites in those areas.

BRIAN GOLDMAN: But I've also heard that you can get bitten by by ticks when you're gardening.

ISAAC BOGOCH: Sure. I mean, again, it's you know, the ticks don't read the textbooks. So certainly they could be they could be anywhere. But, you know, the probability of a tick encounters really in wooded areas and grassy areas, and particularly the taller, grassy areas, that's that's where they tend to hang out. But of course, they could be another environments as well.

BRIAN GOLDMAN: So let's drill down a little deeper into Lyme disease. What are some of the most common symptoms and signs of Lyme disease?

ISAAC BOGOCH: Yeah, well, I mean, after a tick bite, if the the tick is infected with Lyme, people can start to experience symptoms anywhere from about 7 to 14 days later. The classic early symptom is something is a classic rash, a characteristic rash called erythema migrants. It looks like a target sign. That's a bull's eye. It's usually greater than five centimeters. It's usually not itchy, and sometimes it's associated with fatigue, with headaches. Sometimes people have fevers, but not not nearly as common. They just might feel a little unwell. But that classic rash is is one of the hallmark features. Now, of course, nothing in medicine, just like nothing in life, is is perfect. And, you know, you might only see that reaction about 80% of people. Sometimes the rash isn't a perfect target sign. But in general, you know, many people that practice medicine have seen this rash and it's sort of a dead giveaway.

BRIAN GOLDMAN: So when should people seek medical care?

ISAAC BOGOCH: I think it's important to seek medical care if you think you have that rash or if you come into contact with the tick and had a tick bite and you're feeling and you're feeling crummy or you're feeling unwell, it's not you know, it's not that hard to make a diagnosis and to to treat. And certainly if people are feeling unwell or concerned, it's always time to go see to seek care.

BRIAN GOLDMAN: Would you say that doctors are becoming better informed about the risks of Lyme disease? Let's include nurse practitioners as well.

ISAAC BOGOCH: Yes. Yes. I think there's lots of room for improvement. But in general in Canada, I think more and more clinicians are aware of why, as a risk, are aware of how to evaluate patients, are aware of what diagnostic tests to send and how to interpret those diagnostic tests, are aware of treatment plans and are aware of where to go for help if they're stuck with the clinical question. Now, like I said, there's room for improvement. But I mean, there's been a big push over the last few years to inform clinicians that life is an issue in Canada. There is a growing burden of Lyme in Canada and it's all there. On the for example, of the Public health Agency of Canada's web page, they talk about Lyme surveillance and Lyme risk. I'm pretty sure every single provincial public health page, they talk about how to send tests for line to the public health labs, and there's guidance for clinicians. So I think we are seeing significant improvement in awareness among Canadian clinicians related to Lyme disease.

BRIAN GOLDMAN: As you know, I'm an emergency physician and I've lost count of the number of patients who come to the ER saying they've been bitten by a tick. So say at that point they have no symptoms of Lyme disease. What treatment, if any, should patients be receiving at that point?

ISAAC BOGOCH: Oh, great question and very timely. So, you know, if someone's been bitten by a tick, you know, the question is, what do you do? Well, for starters, remove the tick and remove the tick as soon as possible. If the tick is indeed a black legged tick and the tick is removed in less than 24 hours, meaning the tick has not been attached for more than 24 hours. You're okay. It takes some time for Lyme to actually transmit. Once the tick is attached. So in general, not always, but in general, people will be just fine if that tick is removed quickly and within a 24 hour period of time. If the ticks been attached for longer than 24 hours, obviously you still have to remove the tick, but you can actually give people what's called post-exposure prophylaxis or Lyme post-exposure prophylaxis to reduce the risk of Lyme disease. And if the tick was attached for less than 24 hours and it's still within a 72 hour window of an individual seeking care, you can give a person a dose of doxycycline to help protect against a life infection. We do it a lot in the summer. I don't think enough people know about this. You know, if the tick was attached for greater than 24 hours and it's been more than 72 hours for a person seeking care, it's unlikely that that post-exposure prophylaxis with a dose of doxycycline is going to do anything. But if people do seek care in under 72 hours, you certainly can give people doxycycline. Now, there's a couple of small caveats that kind of annoy me. One is, you know, it's got to be a black legged tick. Okay, that's fine. They're pretty easy to identify. Anyone can go on the Internet and look at the tick and see if it's truly a black like a tick. But those are a predominant tick species, and likely much of the time it is a black like a tick. But sometimes when you're removing the tick, you squish it and it's hard to identify. The second thing is, you know, for this post-exposure prophylaxis, sometimes people say, Well, you have to be in an area where there's a lot of blood. And the answer to that is, come on. I mean, our surveillance is far from perfect. How do you know if that's an area of with a lot of Lyme or not? So I'm pretty liberal in giving up the post-exposure prophylaxis. One really interesting thing and I'm talking from Ontario, so I can't comment for the entire country, but at least in Ontario, pharmacists and pharmacies now have the ability to give Lyme post-exposure prophylaxis. They can give a few other drugs without the need of a physician, but Lyme post-exposure prophylaxis is one of them. So we know the challenges of health care in Canada right now. We know how hard it is to seek care with a primary care provider and the wait times. We know, of course, you're an emergency room physician. Sometimes the wait times are are challenging as well. Well, there's plenty of pharmacies and pharmacists in the country, and at least in Ontario, you can go to a participating pharmacy and get post exposure prophylaxis for life, which I think will be a great help to many people, especially those who live in a Lyme endemic area.

BRIAN GOLDMAN: So, Isaac, the point that I want to underscore here that you've said when you when you talk about being liberal with giving an antibiotic to prevent in the case of a tick bite, if somebody's been bitten by a blacklegged tick, you're saying don't spend a lot of time thinking, what's the prevalence of Lyme in this area? Do I need to really worry about Lyme? Just treat it.

ISAAC BOGOCH: That's. Well, post-exposure prophylaxis. Yes. Yes. I'm not treating Lyme. We're prophylaxing Lyme. But yes, I completely agree. Yeah.

BRIAN GOLDMAN: Exactly.

ISAAC BOGOCH: Yeah, exactly. It's a one time dose of doxycycline, 200 milligrams. It's like, what are we going to mess around for and start figuring out is there a high prevalence or a median prevalence of Lyme? Like, is it a blacklegged tick? Has it been on you for less than before, for greater than 24 hours? And you know, did you seek care in that 72 hour window? Sure. Here's your 200 milligrams of doxycycline. I think the other key point here is if you give the wine post-exposure prophylaxis or not, you still have to counsel the patient and say, listen, nothing's perfect. Monitor your symptoms over the next month. If you develop that classic rash, that target rash, the erythema migrans rash or other symptoms like headaches or fevers or malaise. Hey, come on back, get care. Let's get a Lyme test and see you don't. But in general, the post-exposure prophylaxis is pretty effective.

BRIAN GOLDMAN: So how do most people get diagnosed with Lyme disease?

ISAAC BOGOCH: Usually it's it's through their primary care provider. You know, someone comes into clinical care, they say, you know what, I had a tick bite. I have a rash. A clinician says, oh, tick bite, rash, make the connection, do the test, test positive, treat it. And they're usually good to go. But, you know, there's there's lots of different ways for people to come to medical care. Sometimes there's no history of a tick bite. Sometimes there's a tick bite. But, you know, less typical symptoms. But Lyme is still on the differential diagnosis and considered in some and the clinician sends off the test. So there's there's a lot of different ways for people to come to medical care.

ISAAC BOGOCH: I think it's extremely important. Early in the course of illness, the test can be negative, and that's also important to know. So, for example, if someone just has a rash of erythema migrants and it's really early in the course of illness, the test can still be negative. And that's important for clinicians to know because, you know, if you have someone who is in the right place with the right exposures, who has the right type of, you know, a rash, consistent or a syndrome consistent with Lyme and you have a negative test, we know that that can still be alive and we still treat that. But for other cases, you know, it's it's still important to you know, if there's any any concern, it's important you have a negative test. You can always repeat that test 2 to 4 weeks later. And and, you know, that test should be positive 2 to 4 weeks later if there's any ambiguity, because, you know, there's certainly a lot of syndromes out there, a lot of illnesses out there that can mimic Lyme, that aren't why And you don't want to fall into what we call an anchoring bias and say, oh, you know what, it's got to be Lyme and don't consider other diagnoses. So it really is important to confirm this infection with the test. And, you know, Ontario has a pretty reasonable testing algorithm here. The public health labs are some people might argue with me, but I think the public health lab does a very good job with with their Lyme testing.

BRIAN GOLDMAN: You've already mentioned doxycycline to prevent post-exposure prophylaxis. What are the treatment options for somebody with Lyme disease?

ISAAC BOGOCH: Well, there's there's lots of different antibiotics that we can use to to treat Lyme. Doxycycline is one of the drugs that we use very regularly. There's other medications that are widely available. For example, amoxicillin can be used, another drug that's also widely available through Roxanne. Some people might have allergies to amoxicillin or intolerance to doxycycline. You can use a zithromax and or clarithromycin. There's no shortage of of antibiotic choices for for Lyme. And you know, there's various situations someone might be pregnant you don't want to use doxycycline during pregnancy so you use one of the other options like we have a lot of different choices depending on the clinical scenario.

BRIAN GOLDMAN: Just taking a step back, Isaac, to what extent are cases of Lyme disease being under-diagnosed and undercounted in Canada?

ISAAC BOGOCH: My guess is it's pretty significant. I think there's probably a lot more Lyme than we're actually collecting and documenting here. And if you look at the the data from the Public Health Agency of Canada, you know, there's anywhere from 2 to 3000 cases per year that were that are are reported. But, you know, we know that there's a growing population living in areas that are endemic for Lyme. We know Canadians are out and about in the summer months. We also know, you know, we still have room for improvement in terms of informing clinicians and of course, the general population of, why risk? So there most certainly are cases that are going under-diagnosed.

BRIAN GOLDMAN: The surest way to prevent Lyme disease is to avoid tick bites. So what are some of the more effective ways to do that?

ISAAC BOGOCH: A couple of easy tricks. One is just be aware that you're the area that you are in. For example, wooded areas or areas with tall grass are are areas where Lyme and ticks are present. Insect repellents are extremely helpful. Long pants are helpful as well. But, of course, you know, sometimes it's really hot. I think it's impractical to tell everyone to wear pants, you know, on a, you know, 35 degree Celsius day. So, you know, but that certainly won't pass. Can can help protect against tick bites. I think the real key here here is when you come back from a wonderful day outside, it's just important to do a tick check. And that's not something you do by yourself. It's a team sport. It's really helpful to have someone look at maybe the back of the legs or the lower back areas where you might not be able to visualize yourself as well and really have a have a good look up and down to see if there's any ticks. And remember, these can be really small. The nymphs are tiny, they can be two millimeters. So it's not just looking. You can also if you're by yourself, you just rub your hands down the back of your legs, for example, to see if you feel a little bump there. And again, they're pretty easy to remove, but it's important to actually look for them when you come back in.

BRIAN GOLDMAN: How do you remove a tick?

ISAAC BOGOCH: Get some tweezers. You really want to grasp the tick as close to the head as possible and you pull up in a perpendicular to to the skin in a vertical way. You want to be sure that you get everything out. So including the mouth pieces of the tick. So you're going to be sort of it sounds funny, but gentle but term when you're removing them, it's not that hard to do. I think people can do this on their own pretty easily. There's wonderful videos available on the Internet, on YouTube and whatnot to show people how to remove ticks, but it's really as simple as grab it with tweezers, grab it as close to the head as possible, pull it out slowly and all is well. BRIAN GOLDMAN: Those are most of the questions I want to ask. What's the most important thing you want to leave people with?

ISAAC BOGOCH: Enjoy the outside. We are so lucky to live in Canada. We have beautiful wilderness and it's just important to recognize that yes, there were ticks out there. Yes, some takes can transmit Lyme and other infections, but that's no reason to avoid the outdoors. Simple things like insect repellent and tick checks afterwards are very, very easy to do and can reduce the risk of tick bites. If someone gets a tick bite, it's not the end of the world. Pull the tick out. If the ticks been on for greater than 24 hours, you can get an antibiotic to at least reduce the risk of getting mine. But I really hope people enjoy the Canadian outdoors. It's gorgeous and we should all be up there as much as possible.

BRIAN GOLDMAN: Those are great words of advice. Isaac Bogoch, thank you so much for coming back on to The Dose to talk about Lyme disease and about tick bites.

ISAAC BOGOCH: My pleasure, Brian. Always happy to chat.

BRIAN GOLDMAN: Dr. Isaac Bogoch is an infectious diseases physician at University Health Network in Toronto. Here's your dose of smart advice. Climate change and the resulting warmer weather mean that tick populations are growing. Across Canada, ticks carry several diseases, but Lyme disease is the most common. Ticks are most commonly found in wooded areas. Leisure activities in which you risk being bitten include hiking, mountain biking and golfing. High risk occupations include landscaping, forestry, brush cleaning, land, surveying and farming. Ticks are usually more active in the months of April through October and peak in the summer months of June through August. The best way to prevent Lyme disease is to avoid tick bites by wearing protective clothing and by using insect repellent. Perform a tick check as soon as you leave a wooded area. Ask a partner to check for ticks on the backs of your legs and your lower back. If you get bitten by a tick, remove it immediately using a pair of tweezers as close to the ticks head as possible. Pull vertically on the tick to remove it. Ticks removed within 24 hours of the bite require no further treatment for tick bites that are more than 24 but less than 72 hours old. A single dose of antibiotic can prevent Lyme disease. Symptoms of Lyme disease tend to occur 10 to 14 days following a tick bite, but can occur earlier. Typical symptoms include a target or bullseye rash as well as fever, fatigue, malaise, as well as joint and muscle aches. Lyme disease is usually treated successfully with a course of a wide selection of antibiotics. Keep in mind that some people with Lyme disease do not recall getting a tick bite. All cases of Lyme disease need to be treated. If you have topics you'd like discussed or questions answered, our email address is The Dose at cbc.ca. If you like this episode, please give us a rating and review wherever you listen. This edition of The Dose was produced by Isabelle Gallant. Our senior producer is Colleen Ross. The Dose wants you to be better informed about your health. If you're looking for medical advice, see your health care provider. I'm Dr. Brian Goldman. Until your next dose.

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What do I need to know about ticks?- Transcript

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