Dr. Blair Bigham:
I'm Blair Bigham.
Dr. Mojola Omole:
I'm Mojola Omole. This is the CMAJ podcast. So today, Blair, we're going to be talking about something that I didn't think we were going to be talking about in 2024, in the year of our Lord.
Dr. Blair Bigham:
I thought we would never see this in our lives, Jola.
Dr. Mojola Omole:
I've never seen it in my life. So we're going to be talking about measles. We have two articles that's talking about measles vaccination, and then another one, just what we need to know about measles, given that there's a global rise. And now, there's a rise in Canada also of imported cases of measles.
Dr. Blair Bigham:
Yeah. And very sad news in Ontario this month, a child died of measles. So this is certainly something that I think is top of mind for anybody working in healthcare right now. How are we going to catch these cases? And if we catch them, what can we do about them?
Dr. Mojola Omole:
And also the travel aspect of it. Especially, I know, Blair, you love to travel.
Dr. Blair Bigham:
Every once in a while.
Dr. Mojola Omole:
Just once in a while. But if you're someone who's probably... For me, I'm going to be traveling to Nigeria in a month and a half with my mum who's 80. So after reading these articles, I'm like, oh, maybe we need to address this when we go to the travel clinic.
Dr. Blair Bigham:
And it's not just travel overseas or to faraway places, just going south of the border can create some risk. We're seeing rises of measles pretty dramatically in some states.
Dr. Mojola Omole:
For sure. So let's first get into the overview of measles, and then an overview of measles vaccination
Dr. Blair Bigham:
That's coming up on the CMAJ podcast. Dr. Sarah Wilson is the lead author of the practice article in CMAJ with a very straightforward title, Measles. Dr. Wilson is a public health physician at Public Health Ontario. Sarah, thank you so much for joining us.
Dr. Sarah Wilson:
Thank you.
Dr. Blair Bigham:
Sarah, describe what we're seeing right now in terms of measles cases in Canada.
Dr. Sarah Wilson:
Well, I think the one way of summarizing it is that we're seeing many more cases of measles in Canada in 2024. And I think in large part, that's a reflection of the fact that we're seeing much more measles activity worldwide. And we know that there is a lot of measles activity in almost all countries in the world right now, and I think there's several explanations for that. One is that we know that the COVID-19 pandemic disrupted immunization services across many different countries, and so that's no doubt a factor in terms of seeing increased global activity in 2024 coming out of the pandemic, but I think it's also fair to say that many countries were experiencing a decline in measles vaccine uptake before the pandemic. So I think it's a bit of an oversimplification to say this is only the consequence of the pandemic. I think a lot of factors in terms of vaccine confidence, declining vaccine acceptance, rates of vaccination, these are trends that occurred before the pandemic. And then with the overlay of the pandemic in terms of disruption to health services, disruptions to immunization services, I think all of this has come together to see what we're experiencing now, which is increased global measles activity. And when we see increased measles activity globally, we do tend to see measles in Canada, despite the fact that we've eliminated measles because people can return home with a measles infection through acquiring infection abroad.
Dr. Blair Bigham:
What would be at stake here if we de-eliminated measles? What if we did have community transmission that was going on and it wasn't imported? What would that mean?
Dr. Sarah Wilson:
So I think that would be very challenging for us as a health system, as a public health system to have the loss of elimination, to have ongoing transmission without being able to clearly link cases and to have widespread transmission and losing control of the ability to rein in measles. And I think one of the reasons why that would be such a horrible outcome if that were to occur is just the very important complications that measles has and the implications to our healthcare system. I think we saw how challenging COVID-19 was to our healthcare systems, and measles has, I think, very important morbidity associated with it. What we're seeing in Ontario is almost a quarter of our cases are requiring hospitalization. And I think that is very much consistent with the literature on measles that about 20 to 25% of cases with measles require hospitalization. This is why measles was targeted for a vaccine program. It's really important, morbidity and mortality, and thinking about vulnerable groups who are at increased risk of measles complications.
Dr. Blair Bigham:
Describe the consequences for those vulnerable groups.
Dr. Sarah Wilson:
So the groups that are at increased risk of measles complications are children under the age of five, pregnant individuals, and individuals who are immunocompromised. And the classic complications that are described after a measles infection are things like otitis media, bronchial pneumonia, diarrhea. I think those are very classically described, especially for young children under the age of five. Pregnancy, of course, is a very important risk group as well. And the pregnancy complications oftentimes in a lot of the measles, outward-facing, public-facing communications really emphasize the risk to the baby. So risk of pregnancy loss, risk of preterm labor and associated complications with that, but I think it's also important to reflect on the potential complications for the pregnant individual themselves in terms of the risks of pneumonia. And we know that when pregnant individuals have a respiratory infection, they are more vulnerable. I'll just also note that one of the very dreaded complications of measles is encephalitis. It's not a common complication of measles, but of course, is a very important one in terms of its long-term permanent sequelae associated with encephalitis.
Dr. Blair Bigham:
Let's go back to med school and get into the sort of measles 101, if we were doing an oral board or a written exam. Let's just go through some of a quick recap. How infectious is measles?
Dr. Sarah Wilson:
So measles is the most infectious virus that we know. If measles is introduced into an unvaccinated population, one case of measles is estimated to infect in the order of 12 to 18 people.
Dr. Blair Bigham:
Wow.
Dr. Sarah Wilson:
So it's incredibly infectious. And I think another challenge with measles is that it is infectious before the onset of the sort of characteristic classic rash. And so people can infect other individuals before perhaps they've even been diagnosed with measles, and I think that's another challenge. In addition to how incredibly infectious measles is.
Dr. Blair Bigham:
Refresh us on the symptoms. What does a rash typically look like, and what other things go along with it?
Dr. Sarah Wilson:
So the classic clinical presentation of measles is fever, and what's a prodromal illness that's often described as the three Cs, so cough, coryza, or otherwise known as runny nose, and conjunctivitis. So people will have these sort of prodromal symptoms for a few days, and then have the onset of rash. The rash is a non-itchy maculopapular rash. It starts on the face, and then it spreads down onto the body, the trunk, and then outwards to the arms and legs.
Dr. Blair Bigham:
How would a family doc or an ER doc confirm that someone has measles when they're looking at that type of symptomatology and viral rash?
Dr. Sarah Wilson:
So I think one of the most important things is to be thinking about measles, to have measles in the back of your mind as a clinician when you're evaluating people with fevers and rash illnesses, especially in people who are unimmunized or under-immunized or people who don't have their immunization, they don't know what their immunization status is. And so in terms of diagnosing measles, there's two sets of tests that are recommended. So one is diagnostic serology, so taking a blood specimen, looking for both IgM and IgG, measles serology, but that's not enough. We really need specimens collected for measles PCR testing. So we recommend an upper respiratory specimen, like a throat swab or a nasopharyngeal swab, as well as a urine. And that's really important because we know we can't just rely on serology to diagnose measles. These PCR specimens are really incredibly important for the diagnosis.
Dr. Blair Bigham:
And so we should be doing a urine PCR and a throat swab?
Dr. Sarah Wilson:
That's right. That's right. A throat or a nasopharyngeal swab, but we recommend NP or throat in addition to a urine.
Dr. Blair Bigham:
Once someone is diagnosed with measles, is there anything we can do about it?
Dr. Sarah Wilson:
So I think there's different ways of thinking about that question. I think for the individual who has measles, they obviously receive supportive care and they're recommended to isolate. So in terms of ensuring that if they're well enough to just be at home, that they're not leaving their house, that they're not exposing other individuals to measles while they're infectious. But from a public health response, there's quite a bit of activity that's undertaken after even an individual case of measles is diagnosed, and that involves determining where the person was during their, what we would call in public health, their period of communicability. So the four days before the onset of rash, when they can transmit measles to other people, where were they? Were they in a high-risk setting like a school or a daycare? Were they at a family gathering? Who were the people that were exposed?
And then determining the immunization status of those individuals. Are any of them susceptible to measles or any of them at high risk of measles complications? And if the answer to that is yes, then there are interventions that can be given to reduce the risk either of measles infection or reduce the risk of complications to individuals who are determined to be at risk and susceptible.
Dr. Blair Bigham:
So if you do have measles, how long do you have to isolate for? How long are you infectious?
Dr. Sarah Wilson:
So you're considered to be infectious for... So if you consider the day of rash onset to be day zero, four additional days is what we say. So four days after the onset of rash is what we normally use to say how long someone is infectious for after they've been diagnosed with measles.
Dr. Blair Bigham:
Okay, so it's not like you have to stay home for two weeks or anything like that.
Dr. Sarah Wilson:
That's right. That's right. The only caveat I'd offer to that sort of four days after the onset of rash is for people who have weakened immune systems, people who are immunocompromised, they're known to have the possibility to stay infectious for longer periods of time. So that would be one caveat to that sort of classic sort of four days after the onset of rash.
Dr. Mojola Omole:
If you are an infectious person and you're living with someone who's under six months old or unvaccinated pregnant person or someone who has never been immunized, what do you do then?
Dr. Sarah Wilson:
Yeah, that is a very high risk situation, of course. So anyone in the household setting who is not fully immunized is at increased risk. So some of the groups that you mentioned, for example, an infant who's under six months of age or a pregnant individual, these would be individuals that are not recommended to receive measles-containing vaccine. And they are also individuals who are at increased risk of complications.
So for those groups, as part of our public health response to measles, we'd recommend that those individuals receive what's called immune globulins, so a blood product that contains anti-measles, antibodies to give passive protection so the protection comes from the blood product itself. So for babies under the age of six months, that's recommended up to six days after a measles exposure, as well as for pregnant individuals. And there's some differences in terms of the exact product based on the weight, there's differences in terms of the root of administration. But absolutely for high-risk contacts who are susceptible to measles, they've not been immunized, that's an important product to provide to reduce the risk of infection, but also if infection were to occur, to reduce the risk of complications and severity.
Dr. Blair Bigham:
And I could just order that in the ER or is that a hassle to get?
Dr. Sarah Wilson:
So it is something that is administered in a hospital setting. That's something that wouldn't be given in an outpatient setting. The two products that are given, one is immune globulin through the intramuscular root. The other is immune globulin through the intravenous root. And the recommendation on which product is given depends on the weight of the individual. So if an individual weighs more than 30 kilos, the recommendation is for the product to be given through the intravenous route. And that's something that I'd say does certainly require a fair bit of coordination within the acute care system in terms of ensuring access to the product and oftentimes appropriate infection prevention and control practices where the client or where the patient is receiving it, especially if they're receiving it towards the end of their eligibility for the product on day five or six when potentially they could be incubating measles.
Dr. Blair Bigham:
With rising cases, is there anything else you think physicians need to have front of mind as we go into the summer?
Dr. Sarah Wilson:
I think there's a couple of things. One is when you're seeing patients and if they're presenting with fever and rash illness, one is to consider measles in the differential, order appropriate testing if they have a relevant exposure history in terms of travel or living in an area where there's measles activity. But I think the other, of course, fundamental message when we're talking about increased measles activity is the critical importance of vaccination. We have an incredibly effective vaccine to prevent measles infection, to prevent onward transmission if we have a case of measles introduced into a community. So I think that's critically important in terms of reviewing the immunization status of children, especially young children, to see whether they've received the recommended vaccines. And then the other piece is around vaccine recommendations before travel. And so if individuals and families are planning travel outside of Canada, there are some additional recommendations to ensure people have the optimal protection against measles before they leave Canada and potentially run the risk of exposure given what we've been discussing in terms of increased measles activity worldwide right now.
Dr. Blair Bigham:
Sarah, thank you so much. Dr. Wilson is a public health physician at Public Health Ontario. She joined us from Toronto.
Dr. Mojola Omole:
As Dr. Wilson just said, the primary tool for controlling measles is vaccination, and this is the focus and title of another practice article in the CMAJ. Dr. Samira Jeimy is the lead author. She's a returning guest, and she's the assistant professor and program director for the division of Clinical Immunology and Allergy at Western University. Thanks so much for joining us today.
Dr. Samira Jeimy:
Thank you very much for having me.
Dr. Mojola Omole:
So because measles is so contagious, what level of vaccination do we need to control it on a population level?
Dr. Samira Jeimy:
The more the better, so a hundred percent vaccination rate is the goal, but at least 70% of the population should be vaccinated to provide herd immunity.
Dr. Mojola Omole:
So how effective is the vaccine at preventing measles in individuals?
Dr. Samira Jeimy:
It's an excellent vaccine that's preventing infections, and part of the reason why is because it is the actual virus, but an attenuated or weakened version of the virus. So it's up to 97% effective with two doses.
Dr. Mojola Omole:
And is it possible even if you're vaccinated to get measles still?
Dr. Samira Jeimy:
So yes, almost no vaccine is 100% effective. So it is possible, but it would be very rare. The vulnerable people remain those who either cannot be vaccinated or who are not vaccinated.
Dr. Mojola Omole:
So who shouldn't be vaccinated?
Dr. Samira Jeimy:
So because it is a weakened form of the actual virus, there is some viral activity in the measles vaccine. So people with a compromised immune system, particularly those who are missing the T-cell compartment, so severe combined immunodeficiency, they should not be administered the vaccine as per the National Advisory Committee on Immunization. Pregnant individuals actually cannot get vaccinated as well because the viral particles can actually cross into the placenta. So pregnant individuals cannot be vaccinated. And the minimum age requirement to vaccinate an infant is six months of age. So before six months, their immune system is simply not mature enough.
Dr. Mojola Omole:
How safe is the measles vaccine?
Dr. Samira Jeimy:
The measles vaccine is actually very, very safe. As we know from it being available since the 1970s, we have tons of data on the safety. And rather unfortunately because of a lot of misinformation related to it, misinformation that was since redacted, unfortunately, some information made it into the zeitgeist so that more data has been accumulated on the safety on measles, mumps, rubella vaccine than really any other vaccine, maybe aside from COVID, and it shows that it is exceedingly safe. And there are side effects. There are morbilliform rashes that can happen typically about seven to 14 days after the vaccine, and these rashes tend to be mild. There's fixed generalized cutaneous eruptions that don't involve the mucous membranes, like actual measles infection would. There can be a fever and there can be febrile seizures. So there is that sort of fear around side effects, but they're far less egregious than the consequences of measles infection, which can range from mild to moderate to severe, including mortality, as we unfortunately saw in the news recently.
Dr. Blair Bigham:
Can someone who's just been vaccinated transmit the virus? Can they be infectious?
Dr. Samira Jeimy:
Great question. So in individuals who have significant immune compromise, we do ask the household contacts who are newly vaccinated to minimize their contact with the vulnerable person for about two weeks until the antibodies are generated.
Dr. Mojola Omole:
So can you remind me, because I have an almost four-year-old, what is the vaccine schedule for kids?
Dr. Samira Jeimy:
So the typical public health recommendations, they can vary between provinces, but the first vaccination is usually given at around 12 to 18 months, and the second one is typically given around school entry, but you can give it as early as six months.
Dr. Mojola Omole:
Oh, wow.
Dr. Samira Jeimy:
Although if you give it before 12 months, it doesn't count towards the recommended two doses. So if you give it after 12 months, then it counts towards the recommended two doses, and then some provinces give the second dose at 18 months or beyond, and other provinces give it at four to six years.
Dr. Mojola Omole:
Okay. So I should take him to the doctor's office.
Dr. Samira Jeimy:
If you were born between 1970 and 1990s, then you should take yourself to the doctor's office as well because most people who were born before the 1990s actually only received one dose.
Dr. Mojola Omole:
Oh, okay. That's good to know. What about people who were born before 1970?
Dr. Blair Bigham:
That's not you or I, Jola.
Dr. Samira Jeimy:
Yes.
Dr. Mojola Omole:
No, I was late 70s.
Dr. Samira Jeimy:
It's not us.
Dr. Blair Bigham:
But for the producer, Neil, what should he do?
Dr. Mojola Omole:
Yeah, and he's elderly. He's about 75, so what should we do for him?
Dr. Samira Jeimy:
So for millennials and beyond, essentially have to relook at their vaccination schedule. And if you are traveling to an area that has actual outbreaks or there's a risk of outbreaks, then I would definitely get a booster dose.
Dr. Mojola Omole:
Because that was the question I was going to ask you. I'm leaving to Nigeria for part of the summer, and my mom, who's Neil's age, almost 80, is going with us.
Dr. Blair Bigham:
I don't know if he's going to cut that out.
Dr. Mojola Omole:
And so I don't remember her vaccination schedule and she probably doesn't remember her vaccination schedule, what she had done.
Dr. Blair Bigham:
If you're not sure, can you just get another vaccine?
Dr. Mojola Omole:
Should I just get her another booster?
Dr. Samira Jeimy:
Yes. If you're not sure, just get a booster. The assays of protection for the measles through the blood test, the titers that we do, they're not perfect and they don't have perfect sensitivity and specificity. So rather than relying on a test to reveal if you have measles protection, which again, they're not perfect... And the determination of what is protective for measles, it can vary between individuals. So I would not rely on a blood test. I would just get vaccinated, with the caveat that there is no severe immunocompromise and if you're not pregnant. If you are contemplating pregnancy, you should sort time the vaccine about at least two weeks before. So basically, if you are contemplating getting pregnant, that's the best time to do it. If you are contemplating traveling, you should allow about 14 days to lapse between getting the vaccination and traveling to allow for adequate antibody generation.
Dr. Blair Bigham:
What about if you're pregnant, you can't get vaccinated afterwards, is there any concern about getting your vaccine while you're breastfeeding?
Dr. Samira Jeimy:
This is a question that comes up often. Case by case discussion, but very low risk. Infants have relative immunocompromised because they have immature immune systems, but in most cases safe enough for breastfeeding caregivers. I would have a conversation with the individual in this case,
Dr. Blair Bigham:
And then if you're an emerg doc or a family doc and you see a case and you're like, "Oh my God, I think this is measles," would you vaccinate that person? Is there any benefit to helping them get through that virus?
Dr. Samira Jeimy:
Vaccination within 72 hours of exposure actually does give an immune boost to help the patient mount an immune response.
Dr. Blair Bigham:
So if you saw someone, you're like, "Oh, I'm going to do the throat swab, I'm going to do the urine, I'm going to send it off," would you just offer them the vaccine, because I'm sure it's going to take maybe 48 hours, 72 hours to get those test results?
Dr. Samira Jeimy:
Absolutely.
Dr. Blair Bigham:
Interesting.
Dr. Blair Bigham:
There's certainly a lot of misinformation around the harms of MMR. And for some people, evidence or information can be helpful. But there's also quite a large number of people who are vaccine hesitant, where it's not so much about the misinformation, but more just, we live in a bit of a low trust environment. What have you seen done by frontline physicians that can help address the trust issue before addressing any knowledge gaps that there may be?
Dr. Samira Jeimy:
I do not claim to be an expert in this area, but I think coming from a place where we explicitly say that my interest is aligned with yours in that I want the best outcome for you and your child, it really goes a long way. I think there is a lot of misperception about conflicts of interests of physicians and pharmaceutical industries. I personally am quite transparent in that storing vaccines and giving vaccines is actually costing me, right? It is certainly not being done for financial advantages. So I'm actually quite transparent with what the Ministry of Health reimburses me for giving a vaccine and the cost of storing the vaccine, the cost of paperwork. So I think being very transparent, coming at it from a place without judgment goes a long way. And I think in my head, I always do have that impression. No one's really acting in bad faith when they're in my clinic and not wanting a vaccine. It's because their trust has been eroded. They have heard or read from sources that they rely on that something isn't or is good for them, and then we examine those sources.
Dr. Mojola Omole:
I do also think that part of it is that us as physicians are not necessarily the best communicators.
Dr. Samira Jeimy:
And I think there's data to say that we interrupt patients like five, six times in an encounter because the way that the healthcare model is, we are a volume-based system. I simply have to see 40 patients in a day, and I don't really have the time to spend an hour with each patient. So that does us a disservice. We are not incentivized in any way for spending time with our patients.
Dr. Mojola Omole:
For sure. And I just also think that sometimes in medicine, we rely on the old system of patriarchy that allows people to just believe in doctors. The doctor is always right. However, that's not true anymore, and there's actually a large void because we're not in those spaces that are being filled with the grifters and the people who are trying to, who sell misinformation-
Dr. Samira Jeimy:
Correct.
Dr. Mojola Omole:
... to profit.
Dr. Samira Jeimy:
And it's also important to think about some of the root causes of that distrust, right? There are populations, large swaths of the population who are subject to medical racism, who have not been diagnosed, who have not been treated adequately. I do not at all blame them for not having trust in us.
Dr. Blair Bigham:
Thank you so much.
Dr. Mojola Omole:
Thank you so much for joining us. Thank you for joining us again.
Dr. Samira Jeimy:
Yeah, no, thank you for having me again.
Dr. Mojola Omole:
Dr. Samira Jeimy is a program director in clinical immunology and allergy at Western University. Blair, you are super fascinated about measles and vaccinations. I want to hear your first thoughts.
Dr. Blair Bigham:
Well, I think I want to start by taking a step back and recognizing how deeply emotionally involved we get as doctors when we see people with preventable illnesses and how angry and ragey it makes us, and how easy it is for us to look at the parents or look at the system or look at whatever we feel led to that tragedy and place blame, and just step back from that and recognize that people who do not get vaccines do so because they have good intentions. They do so because they don't trust the vaccine, they don't trust the healthcare system, they don't trust the manufacturers, they don't trust us. It's not because they don't understand what the R0 is or what the fatality rate is.
Dr. Mojola Omole:
Sorry the r-not?
Dr. Blair Bigham:
Like the case fatality rate, the R0, the reproductive transmissibility.
Dr. Mojola Omole:
What is going on with you these days and using these extremely medical-
Dr. Blair Bigham:
Come on, you've watched Outbreak with Dustin Hoffman.
Dr. Mojola Omole:
I've never watched Outbreak.
Dr. Blair Bigham:
Oh my God, best movie ever. Anyways, my point is that it's not about communicating the epidemiology of measles. It's not about communicating the risks and side effects of vaccines or of the disease itself. It is about understanding how over the last decade, we have seen precipitous drops in trust, and now work in a low trust environment. It's not good enough to say, "Trust me, this is what's best for you." It takes more work than that. And as Samira said, we don't really have time often to build that trust, to put that effort into a conversation. And then our own frustrations come in when we hear that some kid died of measles in the city I trained in just this month. So I think it's so hard to balance that emotional reaction to people getting sick from preventable diseases with the compassion needed to understand why do we have a resurgence of a disease that we eradicated in the 90s?
Dr. Mojola Omole:
I completely agree with you. I do think that this, as you said, we work in a low trust environment and part of our role, part of our role, part of our CanMEDS roles is about advocacy and finding much better ways to communicate to our patients on an emotional level. I think we did an episode with a behavior psychologist when we were talking about the COVID vaccine.
Dr. Blair Bigham:
Yeah.
Dr. Mojola Omole:
And I do think that not just with vaccinations or measles, but with any preventable disease that requires that step, that we do need to have a much better approach and more training, frankly, as physicians on how to approach these topics, and probably falls on public health to help offload that work into our family physician's office. So when they come in, they've been primed and they understand why this is important to do.
Dr. Blair Bigham:
But it goes even deeper than vaccines, right? This is all part of the trend. And as people become more polarized, then it's not just vaccines. It could be anything that affects their health. It could be what they eat, where they go to exercise, where they go for healthcare. I think that you're right, Jola, it's something that needs an urgent addressing because we're not trained in how to communicate in hyperpolarized environments. We're not trained in how to build trust in low trust settings. So there's huge gaps in terms of how we've been raised as physicians to function in a world that is really no longer suited to that extinct model of do as I say.
Dr. Mojola Omole:
Yeah. And also not understanding, I think Sami ra brought that up, not understanding the effects of medical racism on many groups.
Dr. Blair Bigham:
Absolutely.
Dr. Mojola Omole:
And as we have an influx of newcomers into the country, that that also comes with them, and that it's part of our job to find a way to communicate effectively in the age of misinformation with our patients.
Dr. Blair Bigham:
That's it for this episode of the CMAJ Podcast. If you like what you heard, please give us a five star rating wherever you get your podcasts. Share it with your networks, leave a comment, and help us get the word out. The CMAJ Podcast is produced for CMAJ by PodCraft Productions. Thanks so much for listening. I'm Blair Bigham.
Dr. Mojola Omole:
I'm Mojola Omole. Until next time, be well.