Infectious Diseases A–Z: Measles cases in 30 states

Measles infections are now confirmed in 30 states, according to the Centers for Disease Control and Prevention (CDC). "We have more measles cases than we have had in the last 30 years," says Dr. Gregory Poland, director of the Mayo Clinic Vaccine Research Group. 

"This is an explosive outbreak."

"This is a reflection of people not being vaccinated and not understanding the severity of measles," says Dr. Poland. "If you get measles, you have about a 1 in 1,000 chance of having encephalitis. That is an infection of the brain, and it will change your life forever if you survive it."

Worldwide, more than 100,000 people a year, mostly children under 5, die from measles. 

Watch: Dr. Gregory Poland talks about measles

Journalists: Broadcast-quality sound bites with Dr. Gregory Poland are in the downloads at the end of the post. Please "Courtesy: Mayo Clinic News Network."

Measles is a highly contagious viral infection that spreads when an infected person coughs or sneezes. The virus can live up to two hours in an airspace where an infected person coughed or sneezed. Up to 90% of the people close to the infected person who are not immune or vaccinated also will become infected.

"This is, again, preventable, and this all emanates from the false notion that in some odd manner measles vaccine could cause autism. That is not true," says Dr. Poland. "It is a falsehood, and it has infected a lot of people's thinking. And as a result, they hesitate to get measles, mumps and rubella vaccine. They reject the vaccine, and it is causing one tragedy after another across this nation and across Europe."

The CDC recommends all children get two doses of measles, mumps rubella (MMR) vaccine, starting with the first dose at 12–15 months and the second dose at ages 4–6.  Teens and adults who are not sure if they are immune should contact their health care provider.