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The Dose Transcript for March 6, 2025

Host: Dr. Brian Goldman

[Music: Theme]

BRIAN GOLDMAN: Hi, I'm Doctor Brian Goldman. Welcome to the Dose. Measles is spreading in Canada and the U.S. A disease that was once close to eradication is causing outbreaks in several provinces in Canada. I had measles, and I saw it decades ago as a resident at SickKids in Toronto. But for most of my colleagues, measles isn't something we've had to think about thanks to the vaccine. Until now, we know you have questions. So, this week, we are asking, what do I need to know right now about measles? Hi, Sumon, welcome back to The Dose.

SUMON CHAKRABARTI: Great to be here. Thanks for having me.

BRIAN GOLDMAN: When was the last time you saw a patient with measles?

SUMON CHAKRABARTI: Well, actually, last year, we had a bunch of cases in the Peel region that originated in travel from India. But then, there were a couple of secondary cases as well. So, I saw it then. Thankfully, so far, I haven't seen a lot in my career, but it is something that's getting to be a bit more and more of an issue as time goes on.

BRIAN GOLDMAN: And prior to seeing those cases last year, when was the last time you saw it before then?

SUMON CHAKRABARTI: I've been here for about 15 years in Mississauga, and I see the occasional one, maybe one every couple of years. I saw a child as an ID Fellow in around 2009. But, you know, we see these. They come from time to time, often presenting in emergency. And like you mentioned, we don't see it as much anymore because of this amazing vaccine. You know, it's not initially recognized. This is something, though, I think, that needs to be on our radar because it's, it's been a global, not just Canada. It's been something that's been exploding globally, particularly post-pandemic.

BRIAN GOLDMAN: And this is why we've invited you to talk about it. But before we begin, can you give us a "Hi, my name is," tell us what you do and where you do it.

SUMON CHAKRABARTI: Hi, my name is Doctor Sumon Chakrabarti. I'm an infectious diseases physician at Trillium Health Partners in Mississauga, Ontario.

BRIAN GOLDMAN: Sumon, what do we know about the measles situation in Canada right now?

SUMON CHAKRABARTI: One thing is for sure is that when you look around this time of year, we tend to get these clusters of cases usually with travel. Somebody will go to a place where measles is still circulating quite rampantly, and then you can bring it back. And the thing is usually, that's not a big issue. You have a case or two, people are vaccinated. It's stopped in its tracks. But unfortunately, even a bit before the pandemic and now post-pandemic, for various reasons, we've seen that the vaccine coverage for measles has dropped, so you can now get more limited outbreaks that are actually going a bit farther than previous. We had this outbreak that we're currently seeing; it was one that actually started in New Brunswick, and it was able to kind of move into Ontario based, you know, travel, people being in contact with each other. And right now, we're sitting at around 180 cases or so since October. Whereas, when you look at last year, we only had 64 cases the entire year. So, this is something that we definitely have our radars on and hopefully we can get this under control.

BRIAN GOLDMAN: Who are the people contracting measles in Canada? And, you know, North America in general? Because there's a pretty major outbreak in Texas as we speak.

SUMON CHAKRABARTI: What we often see is we see these introduction events. And I work in Mississauga. There's a very, very large South Asian population here. So, it's a of particular interest to people that I see, because India and Pakistan still do have a significant amount of measles transmission. So, if somebody brings that in, then, you know, somebody in the community can become infected. And the thing that we see is that it will spread to a greater extent in communities when there's a higher level of people who are unvaccinated. Brian, I got to tell you, I really, really love the measles vaccine. It's one of the best vaccines we have, and it actually prevents transmission and infection itself. So, it is the best tool that we have for this. And when you see communities, particularly pockets of people like not just scattered, you know, pockets of people where people are unvaccinated, you can then see it can spread more easily. And, you know, we'll talk about this, I'm sure. But measles is essentially the most contagious virus that's known to humans. And, you know, it's something that we need to respect. Thankfully, I'm gonna say this again. We have a great tool to prevent this.

BRIAN GOLDMAN: We have long had small pockets, small communities that generally have larger percentages of unvaccinated people. And it wasn't a major problem. You know, a case or two of measles would arrive from other countries. And unless it got to that population, we didn't see a local outbreak occurring. What is happening?

SUMON CHAKRABARTI: One of the biggest things about infectious diseases is that infectious disease, it's so entwined in our lives. And when you see, for example, political turmoil, mass migration of people due to these issues that are happening all around the world, you can see sometimes the movement of infectious diseases. Now, I'm being very careful about this. I don't mean to say I'm blaming anybody, just this is just the pattern that infectious diseases go from person to person, and that's what measles does. So, one thing that we see is that there is measles moving from endemic areas into non-endemic areas that were not being seen previously due to these events. Now, couple that with what happened during COVID. It was political and social upheaval. Many people, through no fault of their own, missed vaccination doses there, for example, given during routine doctor's visits. So now, you're seeing a higher proportion of people that are unvaccinated due to that. Unfortunately, there is also some increasing mistrust in the medical system. You put that together with the increased numbers of introductions into the country, and now you're starting to see a bigger problem. Now, my hope is that we still have a very good amount of vaccine coverage to stop this in its tracks. But the trend that we're seeing is that it is increasing with time. So, we really need to lean into our tool that we have.

BRIAN GOLDMAN: Give us all the ways that measles can spread.

SUMON CHAKRABARTI: Measles is a very, very effective spreader among the population. And the way that you look at it is, first of all, it's person-to-person transmission. And that can happen from respiratory droplets, from sneezing, coughing, talking, there is a small amount that can happen from, say, a surface that has or we call "fomites," infectious particles that you touch, right? These are kind of like the things that you see. But the big thing about measles is something, the term may seem very familiar. It's called airborne transmission. So, let's say if I have a raging measles and I'm in a room, the droplets and particles coming out when I breathe, talk, and cough, they can become suspended in the air and they can be there for up to two hours. So, I can leave the room. And if a susceptible person comes into the room, they can get infected. So, you can see, we talked about this a bit in COVID, but measles is the one that can spread so efficiently. And this is part of the reason why. On one hand, you look at the situation, "Well man, we have this virus that spreads so easily the, a susceptible person is infected. It's a 90 per cent chance that they're going to show symptoms. That's how infectious it is.

BRIAN GOLDMAN: One point I want to tease out here: We often think of communicable viruses infecting one person at a time. Measles can infect many people at a time. You know, we called that in COVID a super spreader. But in fact, everybody who has the measles is potentially a super spreader. And I'm, I'm mentioning that because unlike a lot of other viruses, with measles, I've noticed that on social media, you get warnings, saying that if you were at a restaurant on a certain day, during the hours of such and such and such and such, or another public place like an airport or a shopping mall, and there was a person there who had the measles and you could have gotten infected. In practical terms, how does that speak to how transmissible this virus is?

SUMON CHAKRABARTI: This cannot be stressed enough. It just shows, this is like I said, it is the most infectious virus known to man in terms of its ability of secondary and tertiary transmission. It is extremely transmissible. And you know, when you look at these situations, I've seen these alerts myself. They're out right now, is that if there is one or more infectious people in a room, those particles can hang out for two hours. So, that person doesn't even need to be in the room if somebody walks in for somebody to get infected. So, on one hand, it's not to scare people. It's kind of do, first of all, to give them the tools. And also, if somebody knows that they're susceptible, if somebody knows that they are a potential person that can become infected with measles, they can look out for symptoms. And you know, if they get the rash, they start getting the fever and the redness of the eyes, that type of thing, at least they can have that knowledge to stay out of public to prevent further chains of transmission.

BRIAN GOLDMAN: I remember having measles as a child, as I said. I also remember seeing it as a young physician. Take us through the typical stages of measles, from initial symptoms to the typical rash.

SUMON CHAKRABARTI: Measles, the interesting thing about it: The majority of cases follow a certain pattern. Obviously not all of them, which is part of the reason why you need to have experience, and know what to look for. But in general, what happens is somebody will be exposed to measles, and roughly, roughly about a week to 10 days afterwards, they will start to show symptoms. So, the initial symptoms are similar to a regular cold: Fever, a bit of sore throat, maybe a cough. And people will often start to get like watery red eyes. In medical terms, that's called conjunctivitis. And we call this the prodromal phase. So, at this point you don't have a rash yet, but sometimes you're four days before the rash, but you're already starting to be contagious. So, we've seen people who have things like pink eye, runny nose, sore throat. You don't think about measles right away, but already at that point, that person will start to get infectious. Then, the rash comes. And that's the thing that kind of helps us identify. One thing I'll say before the rash, there is one small clue prior to the rash coming that if you look into the person's mouth and kind of the soft areas of the tissue, we call it the soft palate, the cheek tissue, the inside of the cheek, you can see these kind of, you know, salt grain spots. It's called Koplik Spots. And that can sometimes be a clue before the actual rash starts the rash. When it starts, you will see it stops, you know, roughly 5 to 7 days after the fever starts and you start to get people that get a thing that starts from the face and then, spreads to the rest of the body downwards. It's almost like the mnemonic that I used to use is that somebody pours a can of paint on you. It starts in the face first, and then it goes to the rest of the body. And that rash, it's like this kind of patchy red rash. You know, I really encourage people to look online to get pictures of it because a picture is worth a thousand words. But that's how we start to see that. And when you get that rash, people are miserable, particularly the children who are inflicted with it. And, you know, in most cases, it goes away. But unfortunately, in some cases, we can see severe complications.

BRIAN GOLDMAN: You're talking about complications here, and we've heard that an unvaccinated child in Texas died of measles. It's the first death in the United States in something like 10 years. Death is only one of the dreaded complications of the measles. How severe an illness can measles cause?

SUMON CHAKRABARTI: My condolences go out to the families of the children who died. This one died in Canada as well. The reason why I think it's so important is that you look at this. This is completely preventable in 2025. And that's why even one death for me is too much. When you look at the complications, yeah, death of course, is rare. But you can see other things that, you know, up to 10 per cent, 20 per cent of kids in certain outbreaks can be hospitalized. Some of that is to kind of prevent further transmission. But the things that we see, for example, the measles virus can go to other parts of the body and cause inflammation. You get a severe pneumonia that hospitalizes, especially children. They require oxygen, occasionally a ventilator. You can get inflammation of the heart, with the heart actually starts pumping in a irregular rhythm, which can cause cardiac arrest, or what we call heart failure. Another important complication is meningitis and encephalitis. So, you have the brain like a basketball in a grocery bag, which is the meninges. You can have inflammation of the grocery bag, or you can have inflammation of the brain itself. And that can have very, very bad long term consequences ranging from deafness permanently, difficulty with vision, and cognitive deficits which are permanent. So, these things are quite serious complications. And the last one that I'll say, I've seen a couple of cases of this, particularly because we have some children that were afflicted by this in India and then, came over to Canada, where they're now living. It's something called SSPE, or subacute sclerosing pan encephalitis. This is happening in a child who gets measles as a, as a child, almost always in somebody who is unvaccinated, they recover. And then 10 to 12 years later, they start to develop learning issues, and then, they start to have a cognitive decline until they're in a vegetative state. They lived a decade after the measles infection and then developed these really, really bad degenerative neurological conditions. These are very, very serious complications that can be completely prevented by vaccination.

BRIAN GOLDMAN: We're going to get into that in just a moment. But what age groups are the most vulnerable to some of the, the most serious effects of the measles?

SUMON CHAKRABARTI: The age groups would be, particularly children that are less than a year old, who are not old enough to get vaccinated, and those who have lost the protection of the antibodies from mom, which mom will produce those antibodies to the placenta. But they wane pretty quickly within the first couple of months. So, that's kind of the target group. But look, in terms of infection, anybody that's under the age of around 18 to 25 who is unvaccinated, that's the key here. Unvaccinated are at risk for first of all, getting measles and their risk for complications. But for the most serious ones, it's those children that are under a year of age that haven't been vaccinated. And for kids that have had the opportunity to get vaccinated and haven't, any child under the age of five is at risk of these complications.

BRIAN GOLDMAN: There's no antiviral treatment for measles. You've talked about the vaccine being incredibly effective. How effective is it?

SUMON CHAKRABARTI: This vaccine is incredible. And I always say this because this is the most effective vaccine that we have in practice. And you go from a 90 per cent attack rate if you're unvaccinated, if you're exposed to measles, to something upwards of 95 to 97, sometimes you see certain studies, you see 99 per cent, but you're seeing something in excess of 95 per cent protection when you're fully vaccinated, which means two doses.

BRIAN GOLDMAN: The dosages that you receive depend on the schedule. How long does it take to get fully immunized?

SUMON CHAKRABARTI: If everything is going by schedule, you get your first dose anywhere around 12 to 15 months, depending on circumstances. But usually, a year is a good rule of thumb. And then, the second dose goes in just around school age, which is anywhere from, you know, 3 to 5 years old. I want to put in one plug. I was born in 1979, and an interesting thing is at that time, only one dose of vaccine was recommended, and it wasn't until around 1985 that the children were getting that second dose, that booster, okay? I got my booster, but I got my booster when I was in medical school. The reason I bring that up is because an interesting thing that we saw is that outbreaks in Ontario were following my cohort. So, you saw it happening initially in elementary schools, in high schools, and then in the bars in downtown Toronto, because I was the one were partially protected with the one dose vaccine, but you could still get the disease, especially if you're having a high amount of the exposure. There was a time where I was really advocating for people in my age group to get that second dose of vaccine, and now that's recommended for pretty much all.

BRIAN GOLDMAN: So, people who are unvaccinated or infants who up until that point are too young to have received even one dose... They should get vaccinations, they should catch up. And if they've had one dose, you know, if they're adults who have had one dose, they should get a second dose. If you get that dose, how long does it take for it to ramp up your immunity?

SUMON CHAKRABARTI: Roughly about two weeks. So, it is true that, you know, after you get the vaccine, it takes some time for your immune system to adjust to it. But that said, you know, within a month, you do have excellent protection. The thing that is amazing about this vaccine that after getting vaccinated, every vaccine, it takes a little bit of time as the body adjusts to it. So roughly about two weeks at that point, you have excellent protection. And one very, very important thing is that, yes, immunity does have a little bit of waning with time. But with this vaccine, if you have two doses even decades later, you have an excellent response to protect you against infection from measles. And again, I'll call it that number. We're talking excess of 95 to 97 per cent.

BRIAN GOLDMAN: And just to make a point, the vaccine causes the usual side effects, like a little bit of soreness and redness at the site where you're injected, maybe a tiny fever, maybe you feel a bit punkish for a day or two. It does not cause autism.

SUMON CHAKRABARTI: That's a very, very good point. So, with any vaccine, when you get that immune reaction, that immune reaction is what results in those symptoms of, you know, arm pain, fevers, muscle aches. But this connection that people keep talking about with autism. It has been thoroughly debunked over years and years of experience and data. So, that is not there. So, there is no link between the MMR vaccine and autism. And while there are some side effects, they are very mild. But I think that's the kind of thing when you look at the benefits versus the risk, it's well, well worth it.

BRIAN GOLDMAN: A lot of people are hearing about these outbreaks, and they may be traveling for spring break or for other purposes, and they're concerned about contracting measles. Let's talk about which people should be concerned if they are traveling to an area where there are outbreaks of measles in which people have no reason to fear at all.

SUMON CHAKRABARTI: So, first of all, I'm going to start with the most vulnerable group, and that is children under the age of 12 months, under the age of a year. So, while we do give the vaccine at one year via the schedule, the NACI schedule, you can actually get an early dose. So, for example, children who are in families traveling to South Asia, to tropic countries like Philippines, Indonesia, Thailand, these areas of the world where we still see significant amounts of measles transmission. We would recommend that the parents give an early dose of measles vaccine MMR to the child. Now, what happens is that child will then go when they come back, will still get their regular scheduled dose at 12 months or 12 to 15 months, and school age. But this extra dose offers some protection upfront. For adults, if you're traveling to one of these areas, if you've gotten two doses, look, you're protected. That's great. We should celebrate that protection. But if you're unvaccinated or you've only gotten one dose, it does have a benefit for going and getting whichever doses you are missing. The one issue is, is individuals who are immune compromised. So, for example, people who have things like HIV, if they're advanced HIV, or they have an advanced chemotherapy that's affecting their immune system, they unfortunately can't get vaccinated because the vaccine can make them sick. So, we always try to catch them prior to the immune system being affected by the treatment. For example, pre-transplant or in an individual with HIV, we wait until their immune system has recovered and then, we judiciously give them a vaccine. So, it's a case-by-case basis depending on the risk profile. We really want to target especially those high-risk populations. For example, less than 12 months.

BRIAN GOLDMAN: Doctor Sumon Chakrabarti, thank you so much for explaining things so well and helping us understand what's going on with measles, and what to do about it getting the vaccine. Thank you so much for speaking with us on The Dose.

SUMON CHAKRABARTI: It was a pleasure to be here. Thanks so much for having me.

[Music: Theme]

Speaker 3 Doctor Sumon Chakrabarti is an infectious diseases specialist at Trillium Health Partners in Mississauga, Ontario. Here's your Dose of smart advice. Measles is a highly infectious disease caused by the Measles Rubeola virus. Canada had a recent outbreak in New Brunswick, with more recent outbreaks in Ontario and Québec and sporadic cases in other provinces. In the U.S., Texas is dealing with a significant outbreak in which one child has died. Measles is one of the most highly communicable infectious diseases. It spreads through the air when an infected person breathes, coughs, sneezes or talks. You can also get it by touching tabletops and utensils contaminated with secretions from infected people. The virus can persist in the air or on surfaces for up to two hours after an infected person has left the space. The initial symptoms include fever, malaise, cough, runny nose, and conjunctivitis, or pinkeye. 2 or 3 days after that, patients typically get white spots on the inside of the mouth. Next comes the somewhat painful rash that looks like red bumps that start on the head, often behind the ears, and extend to the rest of the body. People with confirmed measles are infectious from four days before the rash to four days after the rash appears. People who recover from measles have lifelong immunity to the disease. There is no cure for measles, but the MMR vaccine, which protects against measles, mumps and rubella, is highly effective. One dose gets you on average 90 per cent protected, and two doses gets you over 97 per cent protected. The MMR vaccine does not cause autism. Public health officials say you are protected from measles if you were born before 1957, and if you received two doses of the vaccine, or if you have testing that shows you're immune. You don't need a booster if you've had two doses of the vaccine or if you've had measles. People born after 1957 who've had only one dose of vaccine are generally encouraged to get a second dose of the vaccine, especially if they plan on traveling to a high-risk area or are working in a job in which they have a high risk of encountering people infected with measles. It generally takes two weeks for the vaccine to provide immunity. See your health care provider if you think you or a family member has measles. Since the virus is so infectious, it's a good idea to warn your health care provider that you're coming so they can take precautions. One final note: The complications from measles are serious and include heart problems, meningitis and encephalitis, as well as death. Some complications may take years to develop. The only sure way to protect yourself and the ones you love is to get the vaccine. If you have topics you'd like discussed or questions answered, our e-mail address is: thedose@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 Sameer Chhabra and Stephanie Dubois. 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 Doctor Brian Goldman. Until your next Dose.

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What do I need to know right now about measles? - Transcript

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