Here's What You Need To Know About Measles, As The Outbreak Continues To Grow

As a measles outbreak continues to grow in Los Angeles County - as of April 24, the most recent date for which we have data, six people had contracted the disease locally - it's a good time to back to basics: How does measles spread, what are the symptoms and what can we do as individuals to protect ourselves?

We took a look at some of these questions in 2015, when measles was making a comeback after being considered eradicated in the U.S. as of 2000.

Let's revisit, shall we?

HOW DOES MEASLES SPREAD?

One of measles' most frightening features is how contagious it is. People who are exposed to the disease and are not immune have a 90% chance of contracting it. The virus lives for up to two hours on a surface or in the air where an infected person has coughed or sneezed.

SYMPTOMS

People who contract the disease will likely first experience a fever, runny nose, cough, red eyes and a sore throat. After about two or three days, they may develop tiny white spots in the mouth.

From there, a rash of flat red spots - measles' signature symptom - will typically appear, beginning at the hairline then spreading down across the body. Those spots might additionally develop small raised bumps. At the same time as the rash, the patient's fever can spike to over 104 degrees.

More serious symptoms of measles can include pneumonia, ear infections or diarrhea, which occur in about three out of every 10 infected people. About one child out of every 1,000 who gets measles will develop encephalitis (swelling of the brain), which can lead to convulsions and leave the child deaf or mentally disabled.

For every 1,000 children who get measles, one or two will die from it.

THE VACCINE

There's some confusion around who is vaccinated and who isn't, thanks in part to changes made to the vaccination in the 1960s and changes made to the protocol around the vaccination in the 1980s.

The first measles vaccine was introduced in 1963. There were two types of vaccines at the time - one that was inactivated, or "killed," and another that was activated, or "live." The inactivated vaccine was taken off the market in 1967 when it was found to be ineffective, meaning that adults who were born in the 1960s and either don't have immunization records or know that they received the inactivated vaccine aren't considered immune.

In 1989, health officials began recommending two doses of the vaccine. That means that adults born before then may have only received one shot.

DO I NEED TO GET A SECOND SHOT?

Fortunately, one shot still renders you 95% immune. But two shots - the initial shot and the booster - renders you 99% immune.

For that reason, most experts agree that it's a good idea to get a second shot if you know you only received one as a child. In 2015, The California Department of Public Health told KPCC that it "recommends anyone who hasn't already received two doses of the MMR vaccine to do so."

That said, it's not cause for panic if you are unable to do so.

Greg Wallace of the CDC told us in 2015 that the organization's greatest concern is getting unvaccinated people vaccinated, because that's the primary way a disease like measles is going to spread.

For those who do want to get the vaccine or the booster, L.A. County's public health clinics are offering them for free to the uninsured or underinsured.

Editor's note: A version of this story was originally published on KPCC.org

Correction: A previous version of this story stated that there were 38 cases of measles in L.A. County. That is the number for the state of California. In L.A. County, there have been six confirmed cases as of April 24. LAist regrets the error.