From Jan. 1 to March 6 of this year, the Centers for Disease Control and Prevention (CDC) reports 173 cases of measles in 17 states and the District of Columbia. Seventy-three percent of those cases are linked to the outbreak that started at Disneyland. That includes one case in Michigan.
Fifteen years after measles was declared eliminated in the U.S., the virus is still spreading. The Disneyland outbreak touched off a nationwide debate over the importance of vaccines, the rights of parents to not vaccinate and the effect that decision has on all of us.
There is no specific antiviral treatment for measles. Doctors can treat the symptoms, but the disease has to run its course. That's just one reason the return of measles is so concerning to the medical community.
It was in 1963 that the first measles vaccine was licensed in the U.S. In the decade before that, the CDC said three to four million people in the U.S. got measles each year. Of those, 400 to 500 died from the disease, and 4,000 suffered brain swelling.
"Some parents raise the question, 'Well, didn't our grandparents do okay with measles?' and the answer is most of them did, but what about the ones who didn't?" said Dr. Matthew Davis, a professor of pediatrics, internal medicine and public policy at the University of Michigan.
Local 4 asked Davis to help break down the measles risk by the numbers.
The Virus Itself
"Measles is one of the most contagious diseases that we know of," said Davis.
How contagious is it?
According to the CDC, an infected person who coughs or sneezes can infect nine out of ten people who are unprotected against the disease. But you don't have to be in the same room. The virus can survive up to two hours on surfaces or in the air. People are contagious up to four days before they develop the measles rash.
So what's the real risk of your child getting measles? That depends whether or not they're vaccinated, how many people around them are vaccinated and where they travel.
"The risk that your child will get measles is still low," said Davis. "But the risk is going up because we're doing less a good job of vaccinating today in the United States and in Michigan than we have been in the past. When we stop vaccinating as a society, the rates of measles will climb."
Research suggests about 92 to 94 percent of the population needs to be vaccinated against measles to have sufficient "herd immunity" to protect people who can't be vaccinated and babies too young to be vaccinated.
Studies find one dose of measles vaccine is about 93 percent effective at preventing measles. Two doses are about 97 percent effective. That means three out of 100 people who get vaccinated will still get the measles if they are exposed, likely because their immune system didn't fully respond to the vaccine.
Getting the measles
In spite of that high rate of protection, a small but significant number of parents are opting not to vaccinate their children against measles. Many are more concerned about the risks from the vaccine than the disease itself.
"We've done such a good job at vaccinating and protecting kids, who have then grown up to be healthy adults, that those adults themselves don't perceive the risks of the diseases that those vaccines are designed to prevent," said Davis.
"The fact of the matter is the majority of the people who get the measles do okay. But the challenge is, we don't know who's not going to. And a certain number of people who get measles will get life-threatening pneumonia, or meningitis or encephalitis."
According to the CDC, one out of every 10 children with measles will develop an ear infection which can cause permanent hearing loss.
One out of every 20 kids with measles gets pneumonia.
One out of every 1,000 will develop brain swelling -- which can cause permanent brain damage.
For every 1,000 children who get measles, one or two will die from it.
"Those aren't odds I want to take for a child in my family or in my practice," said Davis.
The Vaccine
Of course, the measles vaccine is not without risks. The most common is fever.
"The chance of a fever of 103 or above is about 5 percent of kids," said Davis. "That usually happens between the first 10 to 14 days after the vaccine."
One of 3,000 children will suffer a seizure caused by a fever. One out of 20 kids will develop a rash from the vaccine.
"It's possible that a child, just like an adult, can have a severe reaction to a vaccine," said Davis.
The CDC reports a serious allergic reaction occurs in less than one out of a million doses. Other very rare reported risks include deafness, coma, or brain damage. There are so few cases, it's hard to determine if the vaccine was truly to blame.
In the last 10 years, there have been 57 deaths reported to the Vaccine Adverse Event Reporting System (VAERS) involving the measles vaccine. That does not mean the vaccine caused the deaths. Only that they occurred sometime after the vaccine was given.
What about concerns of autism?
"Many of these stories are based on research from the 1990's from a study in Great Britain," said Davis. "That study was fabricated, it's false. The data was made up, and the person who made up the data was removed from medical practice by boards of practice in the United Kingdom."
Numerous studies since have failed to find a link between the measles vaccine and autism.
To Davis, the measles math is clear: "The benefits of the vaccine far outweigh the risks."
To learn more about measles and the MMR vaccine, click here.