If you were going to write down the most frightening infectious diseases you could think of, measles probably wouldn’t be near the top of your list. Compared with the devastation of HIV/AIDS or the gruesome deaths caused by hemorrhagic fevers like Ebola, measles, with its four-day-long fevers and pervasive rashes, seems like nothing more than an annoyance.
But there is one thing that makes measles unique, and uniquely frightening to public health officials: It is the most infectious microbe in the world, with a transmission rate of around 90 percent. The fact that measles can live outside the human body for up to two hours makes a potential outbreak all the more menacing.
This explains the all-hands-on-deck response when officials with the Massachusetts Department of Public Health learned in late August that two unconnected patients — an infant who’d recently arrived in the United States and a foreign-born adult who’d recently traveled abroad — had visited area hospitals with active measles infections. Identifying the hundreds of people who’d potentially been exposed and then checking their vaccination status required, in the words of Dr. Larry Madoff, director of the state’s Division of Epidemiology and Immunization, a “huge effort” on the part of dozens of state, local, and hospital employees.
Fortunately, there were no secondary infections this time around, a fact that is due in no small part to the impressive vaccine uptake rate in this state. It would be a mistake to assume this will always be the case: Massachusetts is seeing a surge in the number of unvaccinated children. Last year, nearly 1,200 kids entered kindergarten with religious or philosophical vaccine exemptions, roughly double the total about a decade ago.
That mirrors what’s happening across the country. What’s so confounding is that many of the parents requesting exemptions for their children cite specious, disproven fears — such as that the vaccine could cause autism — many of which were based on a fraudulent, retracted study or fringe research published in non-peer-reviewed journals. And the rest of the country hasn’t been as successful as Massachusetts in containing measles infections. Earlier this year, an intentionally unvaccinated 17-year-old from Brooklyn, New York, was infected with measles while on a trip to the United Kingdom. Because he lived in a community with a large number of other deliberately unvaccinated children, the virus quickly spread. By the time the outbreak was contained, 58 people had been infected — making it the largest outbreak in the country in more than 15 years. Nationwide, the Centers for Disease Control and Prevention reported 159 total cases between January and August, which puts 2013 on track to record the most domestic measles infections since the disease was declared eliminated from the United States in 2000.
In a country of more than 313 million, a couple hundred infections doesn’t sound like a lot — and it’s not. But you need only take a look across the Atlantic to find out how quickly measles can spread out of control. In 2007, there were just 44 infections in France, a country where vaccination is recommended but not required. Over the next four years, more than 20,000 additional cases were recorded. Nearly 5,000 of these patients required hospitalization, and 10 of them died.
As the containment efforts illustrate, the fact that there haven’t been any recent deaths in the United States doesn’t mean measles isn’t having a real impact on the economy or on public health. One of the reasons Madoff oversaw an effort in Massachusetts to contact everyone who might have been exposed was to make sure they were OK. Another was to identify anyone who wasn’t vaccinated so they could “isolate themselves and be out of work and out of school.”
The state isn’t releasing estimates for the total cost of these two infections, but a 2010 study in Pediatrics quantified the expense of containing a 2008 outbreak in San Diego in which 11 children were infected — and another 839 people were exposed. That cost the public sector $124,517, an average of more than $10,000 per infection. These are costs borne by all of us: Every tax dollar spent containing measles is a dollar not spent on other public health initiatives.
Maybe you’re not particularly civic-minded. If so, consider this: Forty-eight children too young to be vaccinated in San Diego had to be quarantined at an average cost of $775 per family. Another infant had to be hospitalized after being infected — a harrowing ordeal for that child’s parents and one that rung up almost $15,000 in medical costs.
All of this is worth remembering the next time parents who don’t vaccinate their children tell you they’re making a purely personal choice. This is, of course, technically true, in the same sense that driving after having a few beers is a personal choice. As the mother of the 10-month-old hospitalized in San Diego said, if people want to make that choice, they should go live on an island with its own schools and doctors: “Their own little infectious disease island.”
A measles vaccine promises to contain a disease that infected as many as 4 million Americans each year and killed 400-500.
A panel of experts declares measles eliminated in this country.
With 159 measles infections reported between January and August, this year might see the most US cases in more than a decade.
Seth Mnookin is the associate director of MIT’s graduate program in science writing. His most recent book is The Panic Virus: The True Story Behind the Vaccine-Autism Controversy. Send comments to firstname.lastname@example.org.