CDC Director: obviously in China they're in mitigation stages. They're really now beyond containment

Excerpt from the CDC briefing on Feb. 10, 2020

Relevant explanation from a subreddit user:

Containment = quarantining all known cases with the aim to get the spread to 0; i.e. rapid, drastic action aimed at a narrow range of people - infected, suspected infected, potential contacts.

Mitigation = taking actions to reduce the likelihood of spread (essentially, hygiene measures and reducing all contact between people through self-isolation and other means), so that on average each person infects more than 1 other person and eventually the disease burns out. i.e. widespread, long term action aimed at pretty much everyone.

containment