(CNN) At least 465 cases of measles have been reported in the United States since January 1, according to the latest numbers shared by the US Centers for Disease Control and Prevention on Monday.

That's 78 more cases than the number reported last week and includes cases reported to the CDC by state health departments as of April 4; it therefore does not include cases reported since then.

Florida, Indiana, Massachusetts and Nevada reported their first cases of measles this year, bringing the total number of states reporting cases to 19. The other states that have reported measles cases this year are Arizona, California, Colorado, Connecticut, Georgia, Illinois, Kentucky, Michigan, Missouri, New Hampshire, New Jersey, New York, Oregon, Texas and Washington.

The total number of measles cases nationwide this year "is the second-greatest number of cases reported in the U.S. since measles was eliminated in 2000," the CDC says. That threshold was reached last week when the national total for the year surpassed last year's total of 372. The largest outbreak was in 2014, when there were 667 cases reported nationwide due to several large outbreaks.

Measles is a highly contagious, vaccine-preventable respiratory illness characterized by a rash of flat red spots. Symptoms may include fever, cough, runny nose and watery eyes.