Hi everyone, welcome to the live chat.
I'm joined by Dr. Neil Rau
Hello everyone. Hope you're finished shoveling snow and now ready to think of measles.
A little backgrounder: last year's outbreak in Fraser Valley was much worse (hundreds of cases) than the current situation and was entirely related to unvaccinated folks (graduates of the Jenny McCarthy School of Medicine).
We're talking four cases in TO - we don't know if they are the same strain yet - but we do know that three of four did not get the vaccine.
The main exposure was at Disneyland - not all of CA. In fact, the entire US outbreak right now is 92% related to the exposure at Disneyland (possibly a traveler who came to Magic Kingdom to create some new magic :)). Would not consider California or all of the US as being high risk for measles. Phillippines, Brazil and China are hot spots for measles by contrast.
As long as you are either: a) born before 1970 b) vaccinated with one but preferably two dose of measles vaccine, you're fine.
Some people born between 1970 and 1996 have partial immunity because they received only one dose. If they are going to a hotspot (see map for comprehensive list), either a blood test to confirm immunity, or another dose of vaccine would be wise.
Measles vaccine cant be given in pregnancy (it is a live vaccine, but it is incredibly effective).
If mom is immune (prior disease or vaccination), the baby is protected. Mom cannot get the vaccine less than three months before becoming pregnant.
Infants under one are too young to get the vaccine, and are at highest risk for poor outcomes. Also, malnourished children (as seen in Sub Saharan Africa) do poorly when they are affected. If everyone over one gets the vaccine, local transmission is halted. We continue to have the risk of importation of measles. If are not immune, the virus will come and find you...
E. multiforme is a skin reaction, typically to medications, but sometimes precipitated by infections (e.g. Mycoplasma pneumonia, Epstein Barr Virus). Measles also causes a rash, but it is quite distinctive. Here's good pic of a patient I saw six months ago with measles. In the mouth is the classical "Koplik spot" known as white grains of sand on a red base, opposite the third molar. Now go look in the mirror :)
If mom has the actual disease, congenital infection of the unborn (meaning infection of the fetus) could be serious and fatal as well. Seldom seen in this part of the world, except in communities that eschew vaccination. Sadly more common in developing countries. Worldwide deaths of children under one still exceeds 100,000 / year. The WHO keep trying to tackle this problem without success. See link.
The beauty is that it gives near immediate protection. If given within 72h of exposure to a case, it can protect against the development of infection too. This is used for close contacts who are found quickly. This probably what Toronto Public Health is trying to do right now ("contact tracing")
@Cate - The Canadian Public Health Agency of Canada says that adults born before 1970 can be presumed to have acquired natural immunity to measles, because the disease was circulating widely in those years. However, health care workers, military personnel and travellers to destinations outside of Canada should receive the MMR vaccine, regardless of year of birth to ensure they are protected.
"Outbreak" in Toronto is a smorgasbord of a few cases. Not enough to justify earlier vaccination. Moreover, the effectiveness of the vaccine is lessened if it is given too early, while this strategy is sometimes used in desperate circumstances (big outbreaks, emergency travel to a "hot spot")
To @cate, a comment regarding the subgroups going to "hot spots", another dose might be worthwhile for the reasons of waning immunity that I described before (the 1970 to 1996 crowd who received only one dose).
It's not more dangerous now. However, we are seeing a fringe movement of anti-vaxers who allow for the resurgence of a disease that has not been entirely eradicated. If we all exhibit good civic behavior and get the vaccine, this will prevent further transmission of cases that, with our global village, can't be "kept out" by screening etc. We're also a democracy when I last checked, so we cant force people to be vaccinated against their will. Competing values: freedom and doing the right thing.
To Sandie: measles is a terrible disease. You probably had it, but you were not working in a hospital where cases of fatal pneumonia, brain swelling (encephalitis) would be commonplace. Kids would die here in Canada before the vaccine was introduced in 1963.
@Charsk - Dr. Rau will respond to the 2nd half...but regarding wiping things down: You can catch measles just by being in a room where a person with measles has been -- even after that person has left a room. That's because the virus can hang in tiny water droplets in the air for hours. And almost everyone who has not had the vaccine will get measles if they are exposed to the virus.
We need to strike a balance. The drastic solution is to move to Nunavut and to live in an igloo. Or better yet a desert island. Keep in mind that the overall presence of measles is still very low despite the current advisory. If all of society follows good civic behavior, and if vaccination rates exceed 95% (as they still approach here in Canada), local transmission is very low.
Readers should be aware that France, UK, Switzerland have higher rates of measles than the US. Will that keep you from strolling on the Champs Elysees? I doubt think so...
Just get a second dose. This is what is offered to those who are in the 1970 -1996 crowd, more recently with regards to mumps which is included in the measles-mumps-rubella (MMR) vaccine. Recall the NHL outbreak of mumps a few months ago, and the need to revaccinate players. They should have invited me to help out :)
This would make sense, since the vaccine is a live attenuated (fancy way of saying a "burnt out version") virus. So, it does cause a "subclinical" infection, with virus spread throughout the body to the usual places where measles is found: throat, saliva and urine.
The vaccine virus strain does not cause disease, except perhaps to a bone marrow transplant recipient. WE don't see vaccine-related disease (unlike what happened with the live oral polio vaccine)
We're getting a few questions from people who are planning to travel to Florida, Disneyland and/or elsewhere in the U.S. Should they get their children (under 1 year) vaccinated?
For Florida I would not, but if they were going to the Phillippines or SubSaharan Africa (e.g. as aid workers), I would consider advancing the schedule. Keep in mind that the outbreak was in Disneyland Anaheim California, not Disneyworld Florida.
Once you are vaccinated, you are the end game for the virus to move one. There is no "carrier" state with this virus. Once you see the vaccine strain or the live disease, your body clears it.
Some readers are wondering: They might not know if they/their kids have received the 2nd dose. Is there any harm to getting the booster?
No harm to getting a booster MMR. However, I don't want to create a run on the health care system by having 2.5M Canadians run to the doctor to get a second dose just yet.
I do not think that the rate of measles in Canada or the US warrants a complete overhaul of our current approach to those who have already followed the vaccine schedules that were in place at the time when they were growing up. Just special attention to some of the circumstances that I mentioned earlier.
Of the four, three have not received it. At once this is bad news (why didn't they get the vaccine?!), but it is also reassuring news. It underscores that measles is highly contagious, but that that cases largely affect only those who have not received the vaccine, or who are too young (under age one) to receive the vaccine.
This is a real challenge. Try to emphasize the scientific evidence, but try to be civil in the process of course. (Now I feel like I am writing the Damage Control Eddy column). Mention that legislation will lead to exclusion of those kids from school if a case is identified. You can lead a horse to water, but... (you know the old saying - we're still a democracy - see below)
Matt the measles vaccine is NOT like the flu vaccine which needs to be changed yearly. Thus far, no reports of different genotypes being less covered by the current measles vaccine. Obviously, the vaccine generates a response to the "highly conserved" elements of the virus, that do not differ between strains. Vaccine failures are (inability to mount immunity) still uncommon, but do not relate to shifting strains.
Polio re-emergence is indeed a concern for "failed states" such as Afghanistan, Syria, and also Nigeria, and Pakistan. Luckily, we have really high immunity to Polio here, and Polio is not quite as contagious as measles. Of note, measles can spread in an airborne fashion (sharing the same airspace), whereas polio requires direct contact, or contact with oral or fecal secretions to transmit.
This concludes our live chat Q & A. Thank you so much for your time Dr. Rau.
Excellent questions and thanks for your interest in this topic.