The measles outbreak hopscotching across seven states may have started near Dumbo the Flying Elephant. Or maybe it began during a Finding Nemo Submarine Voyage. Then again, a hapless individual may have breathed in aerosolized measles virus last December during a shared Indiana Jones Adventure ride.



No one knows exactly what triggered this Disney-linked measles outbreak, but officials at the U.S. Centers for Disease Control and Prevention say it was most likely thanks to an overseas traveler visiting Disneyland Park in California late last year while infectious. The genetic fingerprints from nine patients in the growing outbreak are all identical to the measles B3 virus that fueled the massive 2014 measles outbreak in the Philippines. But still CDC cannot pinpoint where the virus stems from because that strain of measles is present in other countries as well.



More than a month after the first wave of Disney-related measles cases sprang up, however, it is clear that the cost of the measles response is considerable. There are now 112 such measles cases with 99 of them in California, according to the latest official count. And in contrast to diseases like Ebola, measles is contagious a few days prior to the emergence of symptoms, so a person may feel well enough to go about his daily life which complicates efforts to tamp down measles spread. The highly contagious respiratory disease typically spreads through the air via coughs and sneezes, but it can survive for several hours after a carrier has left a room.



The state of California, where the case toll is greatest, does not keep total figures on how much the outbreak is costing or how many patients are being tracked, because that work is done at the local level. But clues come from California’s Orange County, the area with the largest caseload. There, every three days a public health nurse calls all persons considered to be at high risk of developing measles due to their known exposure to individuals with confirmed cases of the disease to check if measles symptoms are developing. Such monitoring persists for 21 days after exposure to the virus. The county has not yet calculated a total cost for its measles response, but currently its health department is assessing more than 90 people, with hundreds more being followed by the health care facilities at which they were exposed, according to the Orange County Health Care Agency. The county has tasked eight nurses, five epidemiologists, its medical director and deputy medical director to work on the outbreak alongside support staff. And because public health departments in affected states must divert resources to track and respond to people who have been potentially exposed to measles, the effort affects other public health priorities.



History, too, suggests that affected communities will pay dearly for the epidemic. The CDC has not done an economic analysis on the current ongoing outbreak, but an earlier CDC analysis of outbreaks in 2011 underscores how expensive measles response can get. That year, the U.S. experienced 16 outbreaks with 107 total confirmed cases. According to estimates published in the journal Vaccine by CDC health economist Ismael Ortega-Sanchez and colleagues, a large outbreak (equivalent to the current Disney outbreak), could cost involved health departments a median between $4,091 and $10,228 per day. The figures are estimated tallies for 2011 and assume an outbreak lasts a median of 17.5 days—shorter than the current measles event. (The current outbreak has included seven states since the end of December 2014). Yet at even a fraction of that daily rate, this outbreak will have a hefty price tag. And such economic analysis does not include the weighty costs of parents missing work to take care of sick kids or themselves nor the expenses to the health care system of the “worried well” showing up at their doctors’ offices for unneeded treatment.



A time without measles

Fifteen years ago the U.S. ushered in a new measles-free era. In 2000 it declared that the highly infectious disease had been eliminated in the country, thanks to widespread vaccine use. Americans still got the disease, often from traveling exposures, but it was relatively rare. In the early aughts a median of 60 reported cases occurred each year. But last year the U.S. experienced the highest number of measles cases it had seen in two decades—644. What happened?



Many of the people who got the disease in 2014 were linked to travelers who had encountered the virus in the Philippines, where more than 50,000 cases occurred that year alone. In the U.S. most parents do vaccinate their kids; those who refuse to inoculate their children against preventable diseases, however, elevate the risk for such outbreaks in the U.S. Making matters worse, many of the vaccine-refusers live in clusters, which boosts risks of infection for kids living in such areas.



What’s shocking about this outbreak is that it was so preventable. Even one shot of the two-vaccine series has been proved to be more than 95 percent effective in staving off disease. Without it, measles is so contagious that if one person has it, 90 percent of the people close to that individual who aren’t immune will also be infected. “This is not a problem with the measles vaccine not working. This is a problem of the measles vaccine not being used,” Anne Schuchat, the U.S. assistant surgeon general, told reporters last week during a press call. Most of the measles patients in the current Disney-related outbreak were not vaccinated against the disease or do not know their vaccine status. Yet under the Affordable Care Act health insurance plans must cover the cost of immunizations, including measles. The measles vaccine is also offered for free in many areas to needy families.



A matter for the courts

New Jersey Gov. Chris Christie (R), who vaccinated his kids against measles, said on February 2 that parents “need to have some measure of choice” about vaccinating their children, further inflaming the debate about parental control versus public health good. Sen. Rand Paul (R–Ky.) also chimed in with similar comments during press appearances. Currently, one of the lone obstacles for parents refusing to vaccinate their children can be difficulties enrolling their children in child care or in school. But in many states, including California, parents can fill out an exemption form based on personal beliefs as long as they also get a statement signed and dated by a medical professional that indicates they have received information about the benefits of immunizations and risks around vaccine-preventable diseases.



Sometimes parental choice has been limited. In at least one instance the courts have ultimately intervened to force children to get vaccinated. Public health officials in Philadelphia were granted a court order in 1991 after multiple children died from measles. The city forcibly vaccinated six children even though their families had refused the shots for religious reasons. And as the current epidemic sweeps through the U.S., wreaking havoc on local and state health care system resources, it raises the question if such action may one day need to be taken again. “I would like to view court ordered vaccinations as a ‘break glass in case of emergency’ step when all other measures have failed,” says Robert Ross, who was the commissioner of Public Health for the City of Philadelphia during that measles outbreak. For him, the calculus changes when children are dying, he says.



Parents who refuse to vaccinate their children are disproportionately of higher socioeconomic status than those who adhere to pediatrician-recommended vaccination schedules. As a result, “what ends up happening is poor, lower-income families are carrying the burden of herd immunity for the rest of the population,” Ross observes. Yet he does not blame parents. “We in the public health community just haven’t done a very good job of describing the risks and benefits, and I think the days of expecting parents to get their kids vaccinated because we think they should are over. We have to have a more aggressive strategy of education and outreach,” he says. “I think court-ordered vaccinations should be preserved as an option—but the last option.”

