On this April 11, 2018, file a photo of a high school student using a vaping device near a school campus.
AP Photo | Stephen Sen
The fervor over vaping reached a crescendo this week with two congressional hearings, hundreds of new cases of mysterious pulmonary disease, Juul e-cigarette maker cataclysm, and canceled merger plans between big tobacco companies Altria and Philip Morris.
The Centers for Disease Control and Prevention sent more than 1
The Federal Drug and Drug Administration has launched a criminal investigation into the disease, while Congress and other agencies are conducting their own research into the e-cigarette industry and market leader Yul.  Here's what you need to know:
The epidemic is spreading
The outbreak of foot-and-mouth disease has now spread to 46 countries and one territory with
The first diseases appeared in April and rapidly increased in early July. The first death was reported on August 23 in Illinois. The latest deaths were reported by health officials in North Carolina and Oregon on Thursday. The disease affects mostly men and all reported cases have a history of e-cigarette use or vaping. Of the CDC's demographic data, 61.9% of the victims were between the ages of 18 and 34, and 16.2% were under 18, the agency said Friday.
The specific chemical causing disease to humans is not yet known. Of the 514 cases where the CDC had data on which substance was vaping, 76.9% reported using THC and 56.8% reported using nicotine. More than one-third of patients, 36%, say they use exclusively THC, while 16% say they used only nicotine.
It is not clear what the role of electronic cigarettes is in diseases. Mitch Zeller, director of the Food and Drug Administration's Tobacco Center, said there was no "common theme" in hundreds of cases. Most patients say they vaped THC, a marijuana compound that produces high. But the CDC has not ruled out anything yet, noting that some people report using only nicotine.
Until more information is available, the CDC urges consumers not to buy e-cigarette products on the street or to add substances not provided by the manufacturer. Adults who have used electronic cigarettes containing nicotine to quit smoking do not have to return to smoking, the agency said.
Prohibition of Flavored E-Cigarettes
Ann Shuchat, Director of the Centers for Disease Control (CDC), testified at a hearing at the Energy and Commerce House in Washington, DC on Wednesday, September 25, 2019.
Alex Edelman | Bloomberg | Getty Images
E-cigarette ads featuring young models, vibrant colors and fruity scents have been criticized by health officials, lawmakers and parents for attracting young people to vaping. States, local and international health regulators are taking action.
Michigan was the first state to ban the sale of flavored e-cigarettes, and San Francisco became the first city in the United States to ban the sale of flavored e-cigarettes. Boulder, Colorado, has adopted a similar measure. Washington Gov. Jay Inli has ordered employees to ban the products on Friday.
The Israeli Ministry of Health imposes an immediate ban on the sale of flavored pods with flavored oil, according to the Times of Israel. Health and Human Services Secretary Alex Azar said earlier this month that President Donald Trump was preparing to ban flavored e-cigarettes when the deaths of vaping intensified.
USA. lawmakers are tackling the hearth to look at the e-cigarette industry. An expert panel investigating market leader Yul pressed a senior CDC official on Tuesday for answers to what makes people sick. The FDA has also come under fire from lawmakers and public health groups for dropping the ball when regulating the vaping industry.
An employee picks up a Juul Labs device kit for a customer at a store in San Francisco, CA, on Wednesday, June 26, 2019.
David Paul Morris | Bloomberg | Getty Images
The country's leading e-cigarette maker, Jul, has been under pressure in the past year for allegedly selling to underage children. But now he is fascinated by the public health crisis, even though federal officials say illegal or counterfeit products are to blame. According to doctors, there is still nothing to exclude.
Juul Replaces CEO Kevin Burns with Former Altria CEO K.C. Crosthwaite on Wednesday, a day after confirming it will downsize and hire slowly.
Federal prosecutors in California have also opened a criminal investigation against Jul. then the FDA, over two days of hearings this week, addressing the vaping crisis.
CDC Chief Deputy Ann Schuhat told Congress that the outbreak heightens the need to curb teen teasing. Preliminary data from a federal survey show that more than a quarter of high school students say they use electronic cigarettes.
She also said that doctors worry that the nicotine salts used by Juul make his electronic cigarettes especially dangerous for teenagers. Doctors believe they can cross the blood-brain barrier and cause learning, memory and attention problems, as well as recharge the body to become addicted to other substances, she said.
She added that the CDC is particularly concerned about flavored e-cigarettes, "and the role they play in connecting young people to the life of nicotine, and we really want to avoid another generation's addiction to nicotine, so that addressing directly to scents is a good idea. "
Frank Pallone Jr., DN.J., chairman of the House Energy and Commerce Committee, blamed the surge in e-cigarette use and the epidemic for teenagers on a 2017 decision Food and Drug Administration to delay review waiting for these products.
"I strongly believe that many aspects of the youth epidemic could have been addressed if the FDA had gone ahead with the review of all e-cigarettes on the market when it was first made possible two years ago," he said.
Philip Morris and Altria  Tobacco giants Philip Morris International and Altria have terminated merger talks that would create a $ 200 billion global behemoth.
According to the Wall Street Journal, Philip Morris's board is becoming increasingly uncomfortable from the transaction against the backdrop of the shifting US regulatory environment h
Companies that said in August that they would discuss a possible equity merger now say they will focus on co-launching IQOS, a warm tobacco product, in the United States.
—CNBC Jasmine Wu and Elijah Shama contributed to this report.