That is up from 380 cases reported a week ago as health officials link more illnesses and deaths to vaping. Three-fourths of the cases are male, and two-thirds are between the ages of 18 and 34.

The U.S. Food and Drug Administration is now investigating more than 150 products and substances and said it has activated its criminal investigations arm to explore the supply chain of vaping products and identify the cause of the outbreak. No individual vapers will be targeted, said Mitch Zeller, director of the FDA's Center for Tobacco Products.

Zeller said no single substance or compound, including tetrahydrocannabinol (THC), the high-inducing component of marijuana, or Vitamin E acetate, has been linked to all of the cases so far.

The Centers for Disease Control and Prevention (CDC) has confirmed seven people have died from a vaping-related illness. The confirmed deaths were reported in California (2), Illinois, Indiana, Kansas, Minnesota and Oregon.

"We do expect others," Dr. Anne Schuchat, principal deputy director of the CDC, told reporters, referring to the number of deaths.

A Missouri man in his 40s died of a lung illness associated with the use of e-cigarettes earlier this week, the eighth vaping death in the United States and the first death in Missouri, state health officials announced on Thursday afternoon.

REUTERS