(CN) — Despite the existence of an effective vaccine, the number of measles cases in the U.S. this year has already eclipsed last year’s total.
There have been 387 reported cases of measles in the first three months of 2019, the Centers for Disease Control and Prevention said Monday, already 15 more cases than those reported in all of 2018.
This year’s tally is the second highest since the contagious disease was declared eliminated in 2000, below only 2014’s total of 667 cases.
Outbreaks – defined as three or more cases – are ongoing in California, New York, New Jersey and Washington state, according to the CDC.
Arizona, Colorado, Connecticut, Georgia, Illinois, Kentucky, Michigan, Missouri, New Hampshire, Oregon and Texas have also had reported cases.
Although measles was deemed eliminated from the U.S. in 2000, the disease is still common in many parts of the world, including countries in Europe, Asia, the Pacific, and Africa.
Often spread through coughing and sneezing, the airborne disease is usually brought back into the country by those who have traveled to locations where it is more common. Last year saw 82 cases of measles imported to the U.S. – the largest number in almost two decades.
The CDC says the measles vaccine is 97% effective and that most people who get measles have not been vaccinated.
Measles can be prevented with the MMR vaccine, which protects against measles, mumps, and rubella. Adults can check with their physicians to make sure their MMR vaccinations are up to date.
CDC spokesperson Martha Sharan said in an email Monday that “one in 12 children in the U.S. is not receiving his first dose of MMR vaccine on time, underscoring considerable measles susceptibility across the country.”
She said outbreaks are more likely when measles gets into communities of unvaccinated people, who may have refused vaccines for religious, philosophical or personal reasons.
“These communities make it difficult to control the spread of the disease and make us vulnerable to having the virus reestablish itself in our country again,” Sharan said.
According to the CDC, clusters of cases in the past few years have occurred primarily among unvaccinated people in Orthodox Jewish communities, Amish communities, and a Somali-American community.
Measles symptoms are usually not life threatening. There have only been three measles-related deaths in the U.S. since 2000.
Infected people usually have a fever, runny nose, cough and full-body rash. A low percentage of cases will also see pneumonia and swelling of the brain. Pregnant women with measles may deliver prematurely.
Before the measles vaccination program began in 1963, about 500,000 cases were reported to the CDC each year. Of those, 400 to 500 people died annually and 48,000 were hospitalized.