The Centers for Disease Control and Prevention said Friday that 77% of people who got sick vaped THC, the ingredient that produces a high in marijuana.
A new study published by CDC found two-thirds who got sick in Illinois and Wisconsin said they vaped prefilled THC cartridges that were mostly acquired from friends, family members, illicit dealers or off the street.
The investigation is ongoing. No single device, ingredient or additive has been identified.
The ailment has sickened at least 805 people, from 46 states and one U.S. territory. Thirteen deaths have been reported, from 10 states.
Watch: What You Need To Know About Vaping-Related Illnesses:
Earlier this month, New York became the first state to ban the sale of flavored e-cigarettes in an effort to crack down on the vaping crisis.
According to data from the state health department, nearly 40 percent of high school seniors and 27 percent of high school students overall in the state use e-cigarettes. Use among high-school students went from 10.5 percent in 2014 to 27.4 in 2018.
(© Copyright 2019 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)