Wednesday, June 1, 2016

Measles Doesn't Kill, Except When It Does

There are quite a number of things that people take for granted today, regarding their health, at least in developed nations, like the United States. The majority of the population doesn't think much about the possibility of starving or being malnourished. If we suffer an injury, we can find treatment at a nearby pharmacy or convenience store. For something more serious, medical care is generally not too far away along roads that are kept in good repair. The same thing if we get sick.

There are diseases that we may never see in our lives, anymore, thanks in large part to vaccines. While these diseases may ravage poorer countries that lack the resources and infrastructure to provide a high level of immunization, such as the Philippines, those who live in affluent countries seldom see diseases that were once a common occurrence, let alone deaths from those diseases. This leads to a measure of complacency. Those of us who suffered through vaccine-preventable diseases all too easily think that it was nothing. After all, we made it. We forget, however, those who weren't so lucky, those who are no longer here to tell their story. So it is that we think of diseases like measles as no big deal. We think that it's only dangerous for people "over there".

Unfortunately, measles does not care what we think. It doesn't recognize borders. It doesn't care if you're from the United States, Germany, the Philippines, Pakistan, Nigeria, Brazil. It will infect wherever it can. And it will kill without a care about who you are or what you believe.

It is not uncommon to hear someone on the internet claim that measles isn't dangerous. They will say that we haven't had any recent measles deaths in the U.S. They might argue that the last measles death was in 2003, even though a woman died in 2015 due to measles pneumonia. They may try to convince others that the lack of measles deaths is because the disease has become less serious on its own, and that vaccines have nothing to do with it. Often, they will trot out a graph that shows how measles mortality was decreasing before the vaccine was introduced. Sometimes they'll try to claim that mortality (dying from a disease) is just an extreme version of morbidity (getting sick with a disease), perhaps like a doctor who has lost his license recently said:
As a consequence of natural Herd Immunity, in the developed world measles mortality had fallen by 99.6% before measles vaccines were introduced. A fall in morbidity will have paralleled the fall in mortality (mortality is the extreme of morbidity).
What they do not note, however, is that the mortality rate never dropped below about 1-2 per 1,000 cases to 1 per 3,000 cases, nor do they note that the total number of cases (morbidity) didn't drop until the vaccine was introduced. They will also generally not mention that the "no deaths since 2003" figure represents only lab-confirmed measles deaths. That figure leaves out deaths due to measles that were diagnosed clinically, but did not meet the CDC criteria for lab confirmation. Nor does the figure include deaths due to subacute sclerosing panencephalitis (SSPE), a rare, universally fatal, complication of measles.

Before we get into all of those other deaths, let's take a look at just the lab-confirmed measles deaths. We have two in 2003 and one in 2015. From 2003-2015, there were 1,846 cases of measles in the U.S., giving us a mortality rate of about 1.6 deaths for every 1,000 cases. This doesn't differ much from the mortality rate around the time the vaccine was introduced. The picture changes, somewhat, when we include data from death certificates.

The National Vital Statistics System provides a wealth of additional information on births and deaths in this country. Accessed via the CDC's WONDER database, anyone can look up data on the underlying cause of death, with the caveat that the recorded cause of death reflects the physician's best clinical judgment. It can then be grouped by a variety of criteria, letting users slice and dice things to a great level of detail. We could see how many people died of a particular disease or disease complication, what year they died, what the age distribution was, and so forth.

Once we delve into these death records, we see that there have been more deaths than just the three noted above. For the same 2003-2015 period, NVSS shows 9 deaths from measles with or without complications (it only shows 1 for 2003; this may be because the other death was reported using a non-measles ICD code). There were also 20 deaths due to SSPE in the same period. In fact, if we look at the entire span covered by ICD-10 codes (1999-2014), we get a much grimmer view of this easily preventable disease:

Click to enlarge.
Source: CDC WONDER Database, Detailed Mortality
For the last seventeen years, there have been 51 deaths due to measles and its complications (49 reported to the NVSS plus 1 additional death each in 2003 and 2015 confirmed by CDC). Let's put that into perspective against the number of measles cases overall for those same years:

Note: The 2003 total only includes data from NVSS.
CDC confirms there were two deaths that year
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This should begin to illustrate the toll that measles takes on people, even those living in affluent countries. And remember, this is only looking at deaths from measles. The virus can also cause a number of non-fatal, but still serious complications, such as encephalitis (resulting in deafness or intellectual disability), ear infections (resulting in hearing loss), and pneumonia. Around 1 in 10 kids need to be hospitalized due to measles, though, again, certain doctors who value stories over facts may try to claim that those are "soft hospitalizations". Furthermore, measles can make its victims susceptible to other diseases (even ones they've had before) for up to 2-3 years.

The next time you see or hear someone saying that measles "isn't that bad", remind them that it still kills a fair number of those it infects, even in the United States. Show them these numbers. Remind them that it does more than kill. It also disables. It makes them more vulnerable to other diseases. Even those who are not permanently injured can still spend time in the hospital receiving supportive care. And if they advocate getting immunity "the natural way" (i.e., by suffering through an infection), possibly even recommending hosting a measles tea, do your best to steer them away from such orgies of death. They can achieve immunity without the disease, and without being medically negligent, thanks to vaccinations.
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2 comments:

  1. Not too dissimilar from the Swansea epidemic in the UK in 2012, where 1219 were infected, 88 hospitalized and one died.

    ReplyDelete
  2. This is not an advertisement for a movie, just a suggestion!

    Next month many parents will be taking their children to see a film based on Roald Dahl's book The BFG. Before seeing the movie parents should read the book to their child (or children), and then explain why it is dedicated to a little girl named Olivia.

    ReplyDelete

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