Washington (AFP)

An adult who was vaping died of severe lung disease in the United States, US authorities said Friday, struggling to identify the cause of the diseases of nearly 200 other patients of e-cigarettes.

"Yesterday (Thursday), we were informed of the death of an adult who had been hospitalized for a serious unexplained respiratory illness, after vaping," said the medical director of the US state of Illinois.

Symptoms include coughing, shortness of breath, exhaustion and in some cases vomiting and diarrhea.

Since the end of June, federal health authorities have identified 193 potential cases of severe pulmonary disease in 22 of the 50 US states associated with vaping.

The cause of the diseases was not discovered, but all patients had recently used electronic cigarettes to inhale nicotine and often cannabis, according to the Centers for Disease Control and Prevention (CDC).

"The seriousness of the disease is alarming, and everyone needs to know that e-cigarettes and vaping can be dangerous," said Ngozi Ezike, director of the Illinois Department of Health.

The link with vaping is not yet proven, warned Ileana Arias, head of infectious diseases at the federal CDC.

Although the cases seem similar, "we do not know if they have the same cause, or if they correspond to different diseases that are presented in the same way," said the official.

The substances and brands potentially involved are unknown.

Vaping is the process of inhaling vapors created by high temperature heating of a liquid inside the electronic cigarette.

Fluids often contain nicotine, well studied for decades: it is addictive and affects the development of the brain before 25 years, insists the US government.

Electronic cigarettes do not include many carcinogens found in normal cigarettes, such as tar. But the vapor contains fine particles that penetrate the lungs, and the effect of which is not yet well known. Many are "potentially toxic," warned a report by the American Academies of Science in 2018.

US authorities are alarmed by the popularity of teenage smoking and have launched a policy of firmness against manufacturers to enforce the ban on sales to under 18 or 21 years, depending on the state.

It is possible, says Brian King of the CDC office on cigarette smoking, that lung disease has occurred before but has only been identified by the health authorities' investigation.

© 2019 AFP