The number of measles cases in 2019 has already surpassed annual totals for 2016 and 2017, according to a recent Center for Disease Control and Prevention report.

At least 127 cases have been recorded this year as of last Thursday, which is an increase of 48 more cases since February 4. The annual totals for 2016 and 2017 were 86 and 120, respectively.

CDC officials linked the spread of measles cases to unvaccinated travelers who have brought the virus back from countries experiencing large measles outbreaks, like Ukraine and Israel.

Individual measles cases have occurred in California, Colorado, Connecticut, Georgia, Illinois, Kentucky, New York, Oregon, Texas and Washington. Five outbreaks, defined as three or more cases recorded in an area, have occurred in New York, Texas and Washington.

Among all of the recorded cases, Washington has been hit the hardest by the spread of measles. Almost half of all measles cases—64 in total as of Thursday—have occurred in Washington state’s Clark County, according to a recent report by Center for Infectious Disease Research and Policy (CIDRAP).

Washington Gov. Jay Inslee declared a state of emergency in late January, directing state agencies and departments to divert as many resources as possible to assist affected areas.

While 2019 has seen a sharp increase in measles cases, 2014 holds the record of the most cases in the past decade, according to CDC data. A total of 667 cases were recorded in 2014, more than half of which occurred in one outbreak among an unvaccinated Amish community in Ohio.