Measles is back. Again. An outbreak is percolating that was first documented in California and has spread to four other Western states and Mexico. An unknown person incubating a measles infection exposed an undetermined number of individuals at Disneyland in Anaheim, California, resulting in 53 cases identified to date. The outbreak has caused students to be removed from school for weeks, closed a clinic visited by infected individuals, and resulted in orders of quarantine for many exposed to the virus.
A Southern California pediatrician with ties to the anti-vaccine movement, Bob Sears, has suggested that measles in the United States is nothing to fear, minimizing the potential complications the virus can cause. He does acknowledge in a post that the outbreak is a “public health nightmare,” which Sears himself knows well. A 2008 outbreak of measles beginning with an unvaccinated child returning from Switzerland was a patient of Sears’. That outbreak resulted in 11 cases, led to the quarantine of dozens more, and cost California more than $100,000 to contain.
While the incidence of measles has dropped about 99 percent since the introduction of the vaccine for measles, mumps, and rubella, that doesn’t mean we’re out of the woods. The past year has shown a resurgence in measles infections in the United States. Last year was the worst year for measles in two decades. While we’ve seen fewer than 100 cases of measles in most years since the turn of the century, that number spiked to 644 cases in 2014, from 23 separate outbreaks in 27 states.
Before the vaccine, the United States saw approximately 4 million cases of measles each year and 400 to 500 deaths. These are the stats that vaccine-deniers tend to emphasize—a relatively low number of deaths compared with the number of infections. However, those statistics alone leave out a big part of measles infections. Prevaccine, almost 48,000 people were also hospitalized each year because of measles and measles complications. One in 20 of those infected developed pneumonia. More rarely but more seriously, each year 1,000 became chronically disabled due to measles encephalitis.
Measles is not a benign disease.
But let’s back up for a moment. These data were from the mid-20th century. We’ve made strides in sanitation and nutrition since then, right? Sears and others point out the importance of having a “well nourished” population and living in a developed country. That supposedly makes all the difference.
What many forget is that we had a massive outbreak of measles in the United States from 1989–1991. While our 644 cases in 2014 seems high compared with recent years, 25 years ago measles incidence spiked to 18,000 cases per year, with a total of more than 55,000 infections before the outbreak began to dwindle. It was the largest measles outbreak in this country since the 1970s.
It’s hard to argue that in 1989 we had problems with modern sanitation. Arguably, we were healthier 25 years ago than we are now, if one uses the U.S. obesity rates as one marker of health and good nutrition. We had antibiotics for secondary infections, such as pneumonia, that settle in to measles-infected lungs—and fewer antibiotic-resistant bacterial pathogens than we do in 2015. Measles-associated pneumonia isn’t easy to treat if it’s caused by a “superbug,” and we’ve not had to deal with a huge measles outbreak in the age of methicillin-resistant Staphylococcus aureus, or MRSA, and other drug-resistant bacteria.
Despite our advances and our modernity and our status as a developed country, we still saw 123 measles deaths during this epidemic—here, in the United States, where we get plenty of Vitamin A. There were also 11,000 hospitalizations—fully one-fifth of people infected with measles became sick enough to be hospitalized.
In modern-day America.
Bart Barrett, a physician who saw patients at the height of the epidemic, recalls one of those 123 deaths: a 1-year-old who developed complications. The family called paramedics, but by the time they arrived, it was too late. He was unvaccinated, which was common among young children during the 1989–91 outbreak.
Just as the outbreaks in the 1970s spurred the adoption of nationwide immunization requirements for school admission and attendance, the 1989–91 outbreak led to a modification in the vaccination schedule. While children had previously received a single dose of MMR, recommendations were updated to include two doses in the schedule, and a push was made to get young children vaccinated with their first dose at 12-15 months of age. Prior to the outbreak, it was estimated that only 60-70 percent of preschoolers had received MMR vaccines, leaving a large population susceptible to measles infection. The change in recommendations, along with a number of other policy changes aimed at making vaccines more accessible, collectively led to one of the great public health triumphs of the century: the elimination of endemic measles infection in the United States by 2000.
But as with any infectious disease, the gains we make can be ephemeral. Overall, our vaccination rate with MMR in the United States remains high: at or close to 90 percent by age 3 and about 95 percent by kindergarten. However, national statistics obscure local trends. Those 5 percent who are unvaccinated aren’t randomly distributed throughout the country. Instead, they tend to cluster in location, with many unvaccinated children living in close proximity to others, creating anti-vaccine communities with high susceptibility to measles and other vaccine-preventable diseases. This is where we see explosive outbreaks, such as the 2014 measles outbreak in Ohio’s Amish community.
Nutrition and sanitation are no panacea for measles and no substitute for measles vaccination. Living in the United States does not magically protect you from dying from measles or other infectious diseases. Being generally healthy alone is not a guarantee that you won’t end up hospitalized from a measles infection. Your best defense against measles is an up-to-date MMR vaccine for yourself and your family, checking to see that you live in a neighborhood and school system where others are likewise vaccinated, and spreading the word that vaccines are safe and life-saving. The best way to respect measles is to acknowledge its potential to cause serious illness.