Why quarantine for measles is critical...and quarantine for Ebola was not

Measles has come to the happiest place on Earth. As of this writing, a total of 32 cases of measles have been linked to Disneyland visits that took place between December 17th and 20th. About 75% of the cases identified to date were not vaccinated, either because they chose to forgo vaccines or because they were too young, and at least 6 have been hospitalized.

A measles outbreak is a public health disaster, which can cost into the millions of dollars in health resources. You can be sure that public health workers in California and beyond are working overtime trying to identify cases, educate those who were possibly exposed about how dangerous measles can be, and implement practices so that those who may have been exposed to measles don't further put others at risk. This includes avoiding public places, and practices such as calling ahead to a doctor's offices so possible cases can be ushered into private rooms rather than languishing in the waiting room. A clinic in La Mesa recently closed because of a potential measles exposure. An unvaccinated South Pasadena woman, Ylsa Tellez, received a quarantine order after her younger sister was diagnosed with measles. Tellez is fighting the order and “taking immune-boosting supplements” instead.

Why such extreme measures on the part of public health?

Measles is highly contagious. It's spread by air, and so contagious that if an infected person enters a room, leaves, and an unvaccinated person enters the room hours later, they still can contract measles. Remember a few months back, when that figure was circulating showing that Ebola wasn't particularly easy to spread? Well, measles very much is. The basic reproductive rate for Ebola is around 2, meaning on average each infected person will cause an additional 2 infections in susceptible individuals.

And what’s the reproductive number for measles?

Eighteen. Eight. Teen. I’m not exaggerating when I say that it is literally one of the most contagious diseases we know of.  On average, if you have 10 susceptible individuals exposed to a measles patient, 9 will end up getting sick.

How do we break the cycle of transmission? Vaccination is one way--if one has been vaccinated for measles, chances are very low (but not zero, because nothing is perfect) that they will contract measles. Beyond vaccination, the next-best intervention is to keep those who are infected away from everyone else. The way we do this is by quarantining them.

In public health terms, quarantine specifically refers to the separation of individuals who have been exposed to an infectious agent, *but are not yet ill themselves,* from the rest of society. That way, they’re unable to spread the infection to others. Quarantine makes the most sense when individuals can transmit the infection before they realize they’re sick, which is exactly the case with measles. Infected individuals can spread the virus fully 4 days before the characteristic rash starts to appear, and continue to spread it for another 4 or so days after the rash begins—potentially infecting a lot of people. The problem is, like Ylsa Tellez, they’ll feel fine while they’re out there in the general population. They don’t even have to be coughing or sneezing to spread it (symptoms which can appear prior to the rash)—they can just be breathing (something many of us like to do on a regular basis), and still contaminate their environment with the measles virus.

The difference in transmissibility also makes measles a very different situation from Ebola. Public health officials almost universally condemned quarantine for Ebola exposures, for two reasons: 1) Ebola wasn’t highly transmissible, and  isn’t airborne like measles is; and 2) because Ebola isn’t efficiently transmitted until late in the infection when the patient is very ill and likely bedridden. Quarantining Ebola patients was a political stunt, not a public health necessity.

This is why states have the legal authority to enforce quarantine for infectious diseases: it reduces the risk that asymptomatic, potential disease-spreaders will act as “Typhoid Marys” (another asymptomatic, deadly-disease-spreader), which is in the public interest. And while unvaccinated Tellez feels “attacked” and her mother thinks people are being “not nice” when they demand that Tellez submit to quarantine, their choice not to vaccinate has already put many others at risk of disease and, and is resulting in the quarantine of many other exposed individuals as well. In the 2011 Utah measles outbreak, 184 were quarantined and thousands of contacts traced, at an expense of approximately $300,000. The Disneyland outbreak has already spread into 4 states (California, Utah, Washington, and Colorado). Quarantine is one of our tools to stem the epidemic. In our recent outbreak among Ohio Amish, most willingly submitted to quarantine, and over 10,000 doses of the MMR vaccine were administered. Quarantine is undoubtedly a difficult prospect to face, but perhaps if Tellez and others had been vaccinated in the first place, they, and we, wouldn't be in this situation.

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I don't get it. This woman saw her sister sick with measles. She has to realize what a nasty disease it is. She may not understand precisely how contagious it is (much more than most cold viruses) but if she's a graduate student, she should be capable of looking that up.

And, why do California's colleges not have vaccine requirements?

By Young CC Prof (not verified) on 15 Jan 2015 #permalink

Excellent piece. Particularly liked your points on the reproductive number.
"Eighteen. Eight. Teen. I’m not exaggerating when I say that it is literally one of the most contagious diseases we know of." Perfect.

By Robert Herriman (not verified) on 15 Jan 2015 #permalink

The attention from this person refusing to be quarantined highlights just how much work goes into containing these outbreaks. It also highlights another risk of not being vaccinated - having to miss school or work every time someone around you has measles or another vaccine preventable disease.

Amazingly, there is another measles case in Orange County right now that is thought to be unrelated to the Disneyland outbreak. An unvaccinated teen at Huntington Beach High School. I wonder how many intentionally unvaccinated students and teachers will need to be quarantined at the school...

By Vincent Iannelli, MD (not verified) on 15 Jan 2015 #permalink

The bit about ebola not being transmissible til patient is very ill...then how did Writebol get infected? She was not around such patients...and Dr Khan is said to have gotten ebola from a nurse with whom he had just finished a shift with; he touched the man's skin...a man who was not at dead til days later.

By B R Wilde (not verified) on 15 Jan 2015 #permalink

These people should be sued to recover costs incurred related to their negligence.

Agreed, full civil liability for those who willfully refuse both immunization and quarantine. And eliminate "personal belief exemptions," otherwise I want an exemption from the law of gravity.

In order to make quarantine stick, we need two other things:

One, legislation to prevent people losing their jobs in the event they are subject to quarantine. All that's needed here is to insert a few more words into existing legislation that protects workers' jobs if they are called for jury duty.

Two, funding and requirement for county sheriffs' departments, that are presumably responsible for enforcing quarantine orders, to provide each quarantined person or household with regular grocery/provisions delivery at no cost to them. (A close friend / coworker and I self-quarantine when we have so much as a cold, but we're geeks who telecommute, we're in biz for ourselves, and we each have sufficient no-cook food on hand (routine "preps" for earthquake etc.). Those who don't shouldn't be made to go hungry in their own homes.)

With those two items in place, quarantine would be easily bearable. There would be exactly no excuse for people to refuse quarantine, and those who did could be dealt with strictly.

As for the issue of people feeling socially isolated, there are telephones and email, which are better than a locked hospital ward with neither.

Is Measles then considered a more deadly disease than Ebola because 'Measles is highly contagious' but Ebola isn't 'particularly easy to spread'?

Is Measles then considered more contagious than Ebola?

By Kirsten Dingle (not verified) on 06 Apr 2015 #permalink

A family member's friend contracted Rubella (German Measles) during her pregnancy, and since she was never vaccinated against any disease, she became severely ill. Unfortunately, as is well-known with this disease during pregnancy, her baby was born with deafness, a birth defect.

Not only do you put yourself at risk when the choice is made not to get vaccinated, but the effects it can have on others can be drastic. I think people should be fully aware and informed about the consequences of not being vaccinated and make their decision accordingly.

I can understand that some people believe that if their ancestors were well off without vaccinations, they will be as well. But one thing that should be kept in mind is that along with medicine, micro-bodies have progressed too, and what might have worked 50 years ago might not work today.


Measles are extremely dangerous, and most people are uneducated on the importance of preventing it. Another way that can have a positive impact on the community is to send teams to the schools all around the country to promote vaccinations of children at an early age, as well as information on why it is so important to do so.

By Mia (15127444) (not verified) on 17 Apr 2015 #permalink