The number of confirmed or probable cases of vaping-related illness has risen to 805 across 46 states and one U.S. territory, the Centers for Disease Control and Prevention reported Thursday, as health authorities urge people to stop using electronic cigarettes and other vaping devices while it investigates a rash of illnesses and deaths linked to the products.

That number has jumped by 275 cases, or a 52% increase from 530 last week. Also on Thursday, a spokesperson for the Moses H. Cone Memorial Hospital confirmed the first...