Aug. 20, 2018 -- U.S. health officials are investigating measles cases now reported 21 states and the District of Columbia.
As of July 14, there had been 107 cases reported since the start of the year, according to the U.S. Centers for Disease Control and Prevention.
The cases have been in Arkansas, California, Connecticut, Florida, Illinois, Indiana, Kansas, Louisiana, Maryland, Michigan, Missouri, Nevada, New Jersey, New York, North Carolina, Oklahoma, Oregon, Pennsylvania, Tennessee, Texas and Washington, USA Today reported Thursday.
Most of the people who got measles weren't vaccinated.
This number of cases is on track to exceed last year's 118 reported cases in 15 states and the District of Columbia, according to the newspaper.
Meanwhile, Alaska health officials say a 16-year-old girl visiting the state on a cruise ship last week was contagious after contracting measles during a previous trip to Thailand, and they're concerned that passengers may spread the disease, the Juneau Empire reported.
"We notify health care providers in a situation like this, even though it's a low-risk measles is so highly contagious," said Dr. Joe McLaughlin, Alaska state epidemiologist. "It spreads through the air in respiratory secretions: coughs, sneezes."
Passengers on the cruise, which ended in Seward, may not develop the measles until as late as Aug. 27, USA Today reported.