ILLINOIS • A patient in Illinois is the first to die of a mysterious lung illness linked to vaping, public health officials have announced.
The death occurred as doctors and hospitals nationwide reported an increasing number of vaping-related respiratory illnesses this summer: 193 cases have been reported in 22 US states, including 22 cases in Illinois, officials said.
State investigators have been stumped in recent weeks by the cause. They have not found a common link - other than vaping, in general - among the patients turning up in emergency rooms.
Many patients, including some in Illinois, have acknowledged vaping tetrahydrocannabinol (THC), the high-inducing chemical in marijuana, according to statements from federal and state health agencies.
However, officials do not know whether the ailments have been caused by marijuana-type products, e-cigarettes or some type of street concoction that was vaped, or whether a contaminant or defective device may have been involved.
The Illinois patient's death was disclosed during a news conference held on Friday by officials at the Centres for Disease Control and Prevention (CDC), the Food and Drug Administration (FDA) and the state of Illinois.
They did not provide details about the patient's identity, saying only that the person was an adult who had vaped recently and then succumbed to a severe respiratory illness.
Health officials did not say what product the patient had used, whether it was an e-cigarette or other vaping device; nor did they specify what substance was vaped.
Amid the lack of information, investigators are scrambling to find shared links to the respiratory problems.
Officials said last week that many patients, most of whom were adolescents or young adults, had described difficulty breathing, chest pain, vomiting and fatigue.
The most seriously ill patients have had extensive lung damage that required treatment with oxygen and days on a ventilator.
Some are expected to have permanent lung damage.
"More information is needed to know what is causing these illnesses," Dr Ileana Arias, an official with the CDC, said on Friday.
The Illinois patients have ranged in age from 17 to 38, according to the state health department.
State health departments are handling most investigations into the respiratory illnesses.
"We're at a relatively early stage of understanding," Dr Mitchell Zeller, director for the Centre for Tobacco Products at the FDA, said last Friday.
The collective agencies were throwing "a lot of resources at this", he added, but part of the problem was that state investigations are not always complete, making it difficult to form a clear picture.
One theory, yet unproven, is that illnesses may result from substances that are thought or known to be toxic in vaping products, which use heat to vaporise nicotine and other inhalants.
Dr Brian King, deputy director of research translation at the CDC Office on Smoking and Health, said potential irritants include "ultrafine particulates, some heavy metals, such as lead" and, he said, there "are also concerns about some flavourings".
But he added: "We haven't specifically linked any of those ingredients to specific cases."
Dr Michael Lynch, medical director of the Pittsburgh Poison Centre at the University of Pittsburgh Medical Centre, said the lung injuries doctors there are seeing are consistent with chemical inhalation injuries.
The e-cigarette market has broadened to counterfeiters and a range of devices that can be packed with different substances, including marijuana, but also various flavours and concoctions that may be mixed inexpertly.
Public health officials, however, declined to say if they are seeing a pattern that would make clear whether the problematic products are made by mass-market companies or counterfeiters, or whether the inhalants involved are standard to many vaping products, or made or mixed by consumers themselves.