The U.S. Centers for Disease Control and Prevention on Oct. 17 said the number of lung injuries related to vaping rose to 1,479 as of Oct. 15.
The cases were reported across 49 states, the District of Columbia and one U.S. territory. Deaths related to e-cigarette use grew to 33 across 24 states.
Previously, the CDC reported 1,299 lung injury cases and 26 deaths as of Oct. 8.
The CDC and the U.S. Food and Drug Administration are investigating the cases.
About 80% of patients are under age 35, with 15% under 18. The median age of patients is 23 years, and ages range from 13 to 75 years.
The agency noted that products containing THC, particularly those obtained off the street or from other informal sources, are linked to most of the cases in the outbreak.
The CDC has urged people to stop using e-cigarette products until it completes the investigation. The FDA has warned consumers not to use vaping products containing THC.