The Maryland Department of Health reported this week that there are now 15 cases of vaping-related lung illness in the state, up from five initially reported at the end of August.
State health officials are tracking cases as they continue their investigation, along with federal officials, into the unexplained respiratory problems in people who have used e-cigarettes.
There are 380 confirmed cases nationally in 36 states and the U.S. Virgin Islands, according to the U.S. Center for Disease Control and Prevention. There have been six deaths — in California, Illinois, Indiana, Kansas, Minnesota and Oregon.
All the patients have reported a history of e-cigarette use, so authorities suspect the cause is a chemical exposure. CDC officials say most patients have reported using nicotine and THC, the main psychoactive component of marijuana.
No specific vaping product or substance has been identified in all cases.
Maryland medical cannabis officials also said this week that after they sent a warning letter to users in the state, seven people reported unexplained symptoms. They were told to seek medical attention. Medical providers and dispensaries also were asked to report any possible cases.
State and federal officials plan to update their confirmed cases weekly.