Dr. Mary Jo Trepka is an infectious disease epidemiologist and chair of the Department of Epidemiology at the FIU Robert Stempel College of Public Health and Social Work.
Trepka answers questions about measles and what people can do to stay healthy.
We are seeing a slight uptick in measles cases across the country. What’s driving this?
Measles used to be endemic in the United States, meaning that it was here all the time, kind of like influenza. In 2000, it was declared eliminated and no longer normally present in the U.S. Since then, there have been sporadic clusters, and generally these occur when either a traveler coming into the U.S. or an American resident traveling to a country where measles is common brings the virus back into the U.S. and then exposes people around them.
Typically, it doesn't go very far, but if a case happens to pop up within a pocket of people that are not vaccinated, then it spreads like wildfire. A person with measles will infect up to 90% of unvaccinated people around him or her.
How is measles transmitted?
It’s spread by droplets and by air when an infected person coughs, sneezes or breathes. If someone with measles enters a room, hangs out there for a bit, and then leaves, the virus they leave behind will remain suspended in the air for up to two hours. That’s one reason why it tends to spread rapidly in any group of people who have not been vaccinated.
What are the symptoms to watch out for?
It usually starts out with a fever, cough, runny nose and conjunctivitis, also known as pink eye. Within a couple of days, people will develop a blotchy rash with small bumps that starts at the hairline, goes down the face and then starts to cover the entire body. By the time that happens, people know it's measles. It’s important to note that people are contagious during the four days before they get the rash until four days after the rash appears.
At its most severe, measles can cause people to develop pneumonia or encephalitis, which is an infection in the brain, that could lead to long-term brain damage. It can also lead to death.
What’s the most important thing for a person to do now to protect themselves from measles?
To control measles, we need over 95% of the population to be immune, so people should check that they've been vaccinated with two doses of the MMR (measles-mumps-rubella) vaccine, especially if they are planning a trip to another country. If you’ve had two doses of the vaccine, it is very unlikely you will get infected.
Anyone of college age would already have gotten the vaccine as it is one of the requirements for entering college.
If you were born before 1957, due to how widespread measles was at the time, it's very certain that you were exposed and got measles, so are now considered immune.
Some people cannot get the measles vaccine such as people who have a very weak immune system due to either disease or medical treatments or people who have had an allergic reaction to the vaccine. Such people should consult with their doctor. Someone who is pregnant will need to wait until delivery to get vaccinated.
How does the MMR vaccine work to protect us?
The MMR vaccine is what we call a live-attenuated vaccine, which means that it's a weakened version of the virus that does not make people with normal immune systems sick. It trains your immune system to fight the virus so that when you are exposed to the real thing, your body will be able to react swiftly and effectively.
What should someone do if they suspect they have measles?
They should call their doctor right away to describe their symptoms and to get instructions about what to do. They should not walk into a medical setting without first alerting the clinic because clinic staff will need to take steps to prevent other patients and medical staff from being exposed.
Resources:
Measles information by the Centers for Disease Control and Prevention