Cause of illnesses remains unknown as officials confirm over 1,600 cases
The death toll from mysterious lung illnesses linked to vaping has risen to 34, health officials confirmed Thursday.
The deaths span a wide swath of the U.S. including 24 states, according to data provided by the Centers for Disease Control and Prevention (CDC).
Officials are continuing to search for a cause for the outbreak as the agency verified more than 1,600 confirmed and probable cases in 49 of the U.S.'s 50 states. Alaska is the sole exception.
Additional cases have been reported in the Washington, D.C., and the U.S. Virgin Islands.
Those who have died have ranged in age from 17 - 75 years old, with the median age sitting at 49 years.
Most of the affected patients reported vaping THC, the psychoactive ingredient in cannabis, though investigators have yet to officially determine a cause for the illnesses that have included problems breathing, chest pain and vomiting.
The CDC has termed the cases EVALI, an acronym for e-cigarette, or vaping-associated lung injury.
The agency's latest findings indicate that THC-containing products procured off the street or from informal sources "play a major role" in the current outbreak.
The CDC notes, however, that "no one compound or ingredient has emerged as the cause of these illnesses to date."
"It may be that there is more than one cause of this outbreak. Many different substances and product sources are still under investigation," the CDC said on its website.