US Measles Cases Spike

Last year was the worst year for measles in the US in 15 years, say health officials. The 222 cases marks a big jump from the 60 or so seen in a typical year. Most of the cases were imported, either by foreign visitors or by US residents who picked up the virus overseas. So far this year, 27 US cases have been reported, and it's too early to tell whether 2012 will be as bad. But with large international events like the London Olympics coming up, health officials are urging everyone—particularly international travelers—to make sure they're vaccinated.

Generally, the Americans who got measles last year were not vaccinated. At least two-thirds of the US cases fell into that category, including 50 children whose parents got philosophical, religious, or medical exemptions to skip the school vaccinations required by most states, CDC officials said. (More measles stories.)