In early 2024, clusters of measles outbreaks have appeared in at least six states. Here is a quick timeline of events:
1. On Jan. 4, Philadelphia officials named five hospitals, two healthcare facilities and one day care as the epicenters of a measles outbreak. The state reported eight confirmed cases, and between 20 and 30 people were possibly exposed. A sixth hospital was later named.
2. On Jan. 12, an active measles case was confirmed in Liberty, Mo. Exposure sites included Kansas City International Airport and multiple floors of North Kansas City (Mo.) Hospital.
3. On Jan. 17, Delaware officials reported another case connected to Philadelphia's outbreak.
4. On Jan. 25, the CDC said it has confirmed 23 measles cases nationwide since Dec. 1, with outbreaks confirmed in Philadelphia and Washington state. Seven cases are tied to international travel.
5. On Feb. 1 and Feb. 3, Maryland and Ohio officials each reported one measles case.
6. On Feb. 12, the Minnesota Department of Health said two siblings had confirmed measles cases, CBS News reported.