I've been posting regular updates on the Facebook page about the Disneyland measles outbreak for a couple of weeks now. The latest I've seen is that measles cases in the United States have passed 100 in the month of January, with the majority linked to the Disneyland outbreak. And as an aside for us Iowans, in the last two weeks there have been cases of measles (not all linked to Disney) in Nebraska, South Dakota, Michigan, Chicago, and most recently, Minneapolis. Yeah.
To put that in context, in all of 2014 there were 610 reported cases. And that was the largest year since the early nineties, when there were tens of thousands of cases and dozens of deaths.
As this outbreak has expanded, and as it has become apparent that it is predominantly vaccine refusers driving it, I've noticed websites that are, shall we say, "vaccine averse" quickly try to downplay the seriousness of measles. And sadly, there are even questionable celebrity pediatricians, like Dr. Bob Sears and Dr. Jay Gordon, doing the same. So let's take a look at the true risks of measles, and how dangerous it actually is. With evidence, of course.
What is measles?
Measles is a viral illness that is characterized by a fever, rash, and the "3 C's": cough, conjunctivitis, and coryza (inflamed, runny nose). That might sound like about any viral illness, but measles tends to be high fever (103°-105°), with a somewhat distinct flat, diffuse rash that looks like this, starts in the hairline, and works its way down the body. Another common feature is the presence of Koplik spots, blue spots that appear in the throat, though they don't appear every time.
Measles incubates for 7-18 days after you catch it, but before the rash appears. And here's the kicker: measles is contagious for about four days before the rash, and one day before the fever, meaning people can be contagious without being particularly symptomatic. Staying home when sick just isn't enough when it comes to measles. Measles is not just contagious, it's one of the most contagious diseases on the planet. It's airborne, meaning you don't have to get sneezed on (or touch any body fluid for that matter) to get it. It can hang around in the air for up to two hours.
How dangerous is measles?
Before the widespread use of measles vaccine starting in 1963, nearly everyone got measles. 90% of kids caught it by age 15. Now obviously, most people survived it. Chances are, my kids would as well. But what are the chances they wouldn't? Well, the actual death rate of measles in 2015 in the United States isn't easy to state with certainty, and I could do a whole post just on looking at measles death rates in the developed world. But a quick look at recent outbreaks gives us a ballpark.
You can take a look at the annual reported cases and deaths from most vaccine-preventable diseases here, including measles since 1950. Measles declined dramatically after the vaccine in 1963, until a huge resurgence in the early nineties, leading to the recommendation for the second MMR vaccine at age 4-5. That outbreak had 57,859 cases and 127 deaths in four years, from 1989 to 1992. That works out to a death rate of one in 456 at the time! Even attempting to compensate for underreporting for cases and deaths, the mortality rate during this epidemic settles out somewhere around one to two deaths per thousand cases.
That was 20 years ago, of course, though I would venture to say that there hasn't been a groundbreaking medical advancement that would dramatically cut the death rate of measles since then. Looking at the intervening years (through 2011), there have been 11 deaths and about 3400 cases, working out to a death rate of one in 310 cases. This probably includes a lot of deaths from SSPE, a delayed complication of measles that I will discuss more below, so it's difficult to use that time period as a measure of the death rate.
But, we can look at other recent outbreaks, most prominently in Europe in 2011, which had 26,000 cases and nine deaths, a rate of one death per 3,000 cases. France bore the brunt of it with a death rate of one per 2,300. However, because of differences in health care systems, outcomes in the United States don't always compare favorably with Europe.
Given all that, I tend to estimate a one in one thousand death rate when talking about the United States. I hope (desperately) that it's less, but it will take a very large outbreak to find out. And sadly, we may be on our way to that.
One death per thousand people is too risky for my comfort. What parent would consider a toy or activity "benign" if it caused death in one per one thousand children? Not a big deal? No, I'd get that toy out of my kid's hot little hands faster than you could say "consumer recall." And that's not to mention the other complications. Encephalitis (brain inflammation) occurs in one per one thousand measles cases. Pneumonia in six percent. One in five children are hospitalized. One in 200 have a seizure.
And then there's one of the creepiest, though (fortunately) rarest complications of measles: subacute sclerosing panencephalitis (SSPE). This is where, after the acute illness is over, the measles virus remains dormant in the brain, and six or more years later, causes a uniformly devastating and ultimately fatal illness. It happens only in about one in ten thousand cases of measles, but there is currently no way to detect which measles survivors may harbor the dormant virus. And sadly, SSPE is more common the younger you are when you contract measles. Which means the families with babies too young to be vaccinated (and there have been at least four this year) have years to fret about it, most likely because of someone else's refusal to vaccinate.
So, no, measles is not, overall, a benign disease. With a death rate of one in a thousand (or one in three thousand, whatever we choose), an encephalitis rate of one in a thousand, pneumonia in 6%, hospitalization of 20%, and the rare possibility of a fatal complication years later, in my mind this is an illness to go to great lengths to prevent. The great thing is, we don't have to go through great lengths, as the vaccine for measles is extremely effective and safe. One dose protects 95% of people. Two doses protects 99%. And the vaccine doesn't come close to having these risks. Encephalitis has been reported in one in 1-3 million doses - so rarely that studies can't even show that it is causally connected to the vaccine. Serious allergy is equally rare. If any side effect happens beyond pain and swelling at the site, it's usually fever, sometimes with a rash, that goes away. This happens in about 5% to 15% of people, about 10 days after getting the vaccine.
The problem is, not everyone can be protected with a vaccine. Kids with certain immune problems can't be vaccinated, and are at a higher risk of complications from measles. So are infants too young to be vaccinated - and some have already been infected in the current outbreaks. They rely on everyone else being vaccinated to keep the disease from spreading to them.
How can you help stop the outbreaks?
The good news is, if your children are vaccinated, and your family is vaccinated, the chance of anyone getting measles is extremely small. The vaccine is somewhere around 99% effective after two doses, and provides lifetime immunity for most. Overall vaccine coverage in the U.S. continues to be high.
But national averages don't tell the whole story. One of the main reasons measles is increasing is that vaccination rates are dropping in certain communities. Some wealthy areas of California have vaccination rates as low as South Sudan, and also happen to be the same areas that disease outbreaks are occurring. Unfortunately, some of those areas are also tourist attractions, meaning (as is the case with Disneyland), there is the potential for one outbreak to affect many areas of the country.
So how do you help keep your area from becoming vulnerable to an outbreak? I have three recommendations.
1. Make sure you and your family are up to date on measles vaccine. This goes without saying, but keep in mind that two doses are recommended (usually one at 12-15 months and one at 4-5 years). Many adults only got one dose because the recommendation for the second dose didn't happen until the nineties. Check with your doctor. If you were born before 1957, though, you're off the hook, and considered immune because you almost certainly had the wild disease.
2. Keep up to date about measles, and other vaccine preventable diseases. My two favorite online groups for parents are Voices for Vaccines (website, blog, Facebook, Twitter) and Vaccinate your Baby (website, blog, Facebook, Twitter). They are both very parent-friendly and are easy ways to keep up with the latest news and accurate information about vaccines and preventable diseases.
3. Be willing to speak up. Just a bit. One of the things we know is that when it comes to deciding to vaccinate, parents' social networks are one of the largest influences. Which means what you say helps set the tone in your network when it comes to perceptions of vaccines. You don't have to know everything about them, and you don't have to answer every question or change everyone's mind. Just politely spreading the message, on social media or in real life, that you vaccinate your children and you agree with the overwhelming consensus of scientific studies and experts that vaccines are safe and effective, makes a difference.
It's 2015. Measles is dangerous, but easily preventable. Let's stop the outbreaks.