NEW YORK — Hundreds more Americans have been reported to have a vaping-related breathing illness. And the death toll has risen to 12, health officials said on Thursday.

Number of cases reported

The Centers for Disease Control and Prevention said in total 805 confirmed and probable breathing illness cases have been reported. This is up 52% from the 530 number of cases reported a week ago. At this point, illnesses have occurred in almost every state.

The confirmed deaths include two in California, two in Kansas, and one each in Florida, Georgia, Illinois, Indiana, Minnesota, Mississippi, Missouri and Oregon. The Mississippi death was announced by officials in that state Thursday.

Vaping the common factor

Over the summer, health officials in a few states began noticing reports of people developing severe breathing illnesses, with the lungs apparently reacting to a caustic substance. The only common factor in the illnesses was that the patients had all recently vaped.

As a national investigation started and broadened, reports have increased dramatically.

It’s not clear how many of the 275 added cases occurred in the last week, and how many are being logged long after they happened. The CDC has not released details on when symptoms began in each case.

The agency’s count includes only illnesses that have met certain criteria. Other illnesses are also being investigated.

Vaping products having THC

Most patients have said they vaped products containing THC, the ingredient that produces a high in marijuana. The investigation has been increasingly focused on products containing THC, with some attention on ingredients added to marijuana oil.

But some patients have said they vaped only nicotine. Currently, health officials are advising people not to use any vaping product until the cause is better understood.

Mike Stobbe, The Associated Press

Featured Image: AP Photo/Steven Senne