A new study finds cases continue to occur among U.S. residents who return from trips to other countries, as well as among foreign visitors.
According to researchers, young children are at greatest risk of complications or death from measles. It highly contagious but can be prevented by vaccination.
The report by the CDC finds in the first two months of this year, there were 13 cases of "imported measles" among U.S. residents.
That two month total is said to be comparable to the average annual caseload seen each year between 2001 and 2010.