Vials of measles, mumps and rubella vaccine are displayed on a counter at a Walgreens Pharmacy in Mill Valley, California.

Some 228 measles cases were reported to the CDC in the U.S. between Jan. 1 and March 7, more than half of the 372 cases that were reported during all of 2018. Outbreaks, defined as three or more cases, have been reported in six areas: Washington, New York City, New York's Rockland County, Texas, Illinois and California.

Measles cases have cropped up across 12 states over the last ten weeks — nearly two decades since the highly contagious disease was said to be eradicated in the U.S., according to the Centers for Disease Control and Prevention.

There's been a resurgence in the disease in the U.S. and other developed countries amid increasing resistance from parents to vaccinate their children. Measles is highly contagious, infecting up to 90 percent of unvaccinated people who are exposed to an infected person, the CDC said.

Measles may be best known for the rash it produces.The virus spreads through coughing and sneezing and can live in the airspace where the infected person coughed and sneezed for up to two hours, according to the CDC. People can be infected for days before symptoms appear.

The CDC says the outbreaks in the U.S. are linked to people traveling internationally to countries like Israel and Ukraine that are experiencing large outbreaks. The New York City Health department has confirmed 133 cases of measles in Brooklyn and Queens since October, most of which have isolated to the Orthodox Jewish community and were traced back to recent visits to Israel.

The disease spreads quickly in places where people aren't vaccinated, prompting some lawmakers to pursue making the measles, mumps and rubella vaccine mandatory.

Numerous studies have debunked a now redacted study that incorrectly claimed vaccines cause autism. Most recently, a study of more than 650,000 children from 1999 to 2010 found no link between autism and the MMR vaccine.

Public health officials are trying to persuade so-called anti-vaxxers that modern vaccines are safe and effective and can save children from preventable and deadly diseases like polio.