The outbreak of lung illnesses linked to vaping grew by more than 200 cases in a week, now totaling 1,299, the Centers for Disease Control and Prevention reported Thursday.
Twenty-nine people have died from vaping-related illnesses, health officials said.
The figures mean that 219 new cases and seven new deaths were reported. Cases have occurred in 49 states, the District of Columbia and the U.S. Virgin Islands.
A 17-year-old boy died in the Bronx, New York, last week, the youngest death so far linked to vaping. Utah and Massachusetts officials confirmed their states’ first vaping deaths this week. Indiana health officials announced late Thursday afternoon that two more people had died.
The ages of those who died range from 17 years to 75 years, with a median of 49.
The exact cause of the illness is still unknown. Many of those who became ill had vaped THC, some had used both THC and nicotine, and others report vaping only nicotine.
[Read more: If you vape, Utah experts and others warn that you should watch out for severe flu symptoms]
Federal and state health authorities are testing vaping materials and studying tissue samples from patients in an effort to find the cause of the outbreak. They are particularly concerned about the huge amount of illicit THC products in circulation, which contain unknown mixtures of solvents, diluting agents and flavorings that may be toxic to the lungs.
The U.S. Army said it was treating two soldiers for vaping-related illness. The Army did not say what products the two soldiers had been using, according to an earlier report in The Wall Street Journal. The military has banned e-cigarettes from the exchanges on bases.
Health officials are urging the public not to vape and emphasizing that those who choose to do so anyway should avoid THC, especially products sold on the street or the internet.