After three years on the increase, measles is on its way down again, but health experts say it's too early to tell if the disease might finally be on the decline for good.

The national Centers for Disease Control said Thursday that 3,652 cases of the once-common childhood disease were reported in 1987, down 42 percent from the previous year. It's the first drop in measles reporting since the record low of 1,497 cases in 1983.Measles has fallen 99 percent since the era before measles vaccine was licensed in 1963, and the disease was thought headed for eradication when the record low came in 1983. But the case count then surprised researchers by going back up in 1984, '85 and '86.