Health officials: 14 young people hospitalized after a vaping

And in Illinois, three young people were hospitalized for having severe breathing problems after being vaped, the Public Health Department said Friday. "The names and types of vaping products, as well as the place where they were obtained, are still the subject of an investigation," the department said.

"Some even need help to breathe"

Thomas Haupt, an epidemiologist of respiratory diseases at the Wisconsin Department of Health Services, said on Friday that the cases in his state concerned young people, "normally healthy, and that they had serious respiratory illnesses, and in some cases case, they had to go to intensive care and were placed on ventilators. "

The lung disease seemed to come from an infection, "but every test is completely negative," Haupt told CNN. Regarding the links between cases, "the only thing that comes up at this stage is the vaping, but we do not know what they were vaping, where they got their vaping liquids, all this must be determined at this stage".

Chuck Warzecha, a deputy administrator of the Wisconsin Health Department, said "all had been hospitalized for shortness of breath, fatigue and chest pain, and some even needed help to breathe." While patients "generally improve", it is difficult to know what effects they may experience in the long run, he said.

The majority of Wisconsin cases have occurred in the southeastern part of the state, Haupt said. In Illinois, the three hospitalized patients were from the northeastern part of the state, on the Wisconsin border. It is not yet known whether cases in both states are linked to a common source, such as a vaporizer or an e-liquid.

Ngozi Ezike, director of the Illinois Department of Public Health, told CNN that her team had "been talking to people from Wisconsin" and collecting data and testing. "We have a lot of unanswered questions right now," she said.

As in Wisconsin, Illinois cases included coughing, shortness of breath, fatigue, and sometimes chest pain that worsened over time, according to Ezike. The cases also occurred in people "without known lung problems or with previously diagnosed lung problems," she said.

"Potentially toxic substances" in the vee, says the committee

There were questions about vaping safety even before recent hospitalizations. The American Lung Association, for example, is saying "very troubled by the evolution of evidence about the impact of electronic cigarettes on the lungs".

The organization highlights research showing that the key ingredients of the vape can damage cells or contain "dangerous chemicals" that can "cause lung disease, as well as cardiovascular (heart) diseases."

An expert committee of national academies of science, engineering and medicine reported last year that there was "conclusive evidence that, in addition to nicotine, the most electronic cigarette products contain and emit many potentially toxic substances. "

Scientists do not know how these substances can contribute to lung disease, if at all. However, the committee stated that there is "moderate evidence of an increase in coughing and wheezing in adolescents who use electronic cigarettes" and that they badociate vaping with " an increase in exacerbations of asthma ".

"Who knows how many cases we are going to have"

Gregory Conley, president of the American Vaping Association, said that "unless the ministry conceals information, what we know today does not justify discouraging adult smokers." Use vaping products as an alternative to cigarettes ".

It is "absolutely shameful that health services generally accuse vapers when the facts show that THC cartridges bought in the street are probably the cause of these hospitalizations," he said.

According to his brother, he cited local reports that a hospitalized Wisconsin patient would have purchased THC oil on the street before his breathing problems began to be felt.

However, health officials have yet to identify a common cause for all incidents and Haupt, the Wisconsin epidemiologist, said "we have not yet reported the problem of THC" .

He said that THC, the key psychoactive ingredient in marijuana, "is part of our questionnaire that we examine to determine if there is actually a use of THC and what is the extent among these cases ".

The collection of information has however been difficult because "we deal with minors, so they are not always the most honest when they deal with these issues," Haupt said.

He added that the state was in contact with US Centers for Disease Control and Prevention and that "the FDA had also called". But this is the first time the state has seen a cluster of lung diseases badociated with steaming, Haupt said, and "who knows how many more cases we will have to get".

Susan Scutti from CNN contributed to this report.