Vaping turns deadly: the mystery illness that’s causing alarm in America

US health officials are investigating what might be causing hundreds of serious breathing illnesses in people who use e-cigarettes and other vaping devices. They have identified about 450 possible cases in 33 US states, including six deaths.

A look at what we know so far about the outbreak as the investigation continues:

What are the symptoms?

Patients are coming into hospitals with cough, chest pain, shortness of breath, fatigue and vomiting.

How serious are these illnesses?

Many of the reports involve severe, life-threatening illnesses in previously healthy people. Many patients received oxygen. Some needed to be put on breathing machines before they recovered. Antibiotics didn’t work, and it’s not clear yet whether steroid drugs helped.

What vaping products are involved?

Is there a common thread?

Doctors believe this isn’t caused by a germ. Instead, they suspect chemical exposure. And vape juice contains many possible culprits.

After testing products, New York has focused its investigation on vitamin E acetate, which recently has been used as a thickener, particularly in black market vape cartridges. Suppliers say it dilutes vape oils without making them look watery. Vitamin E is safe as a vitamin pill or to use on the skin, but inhaling oily vitamin E droplets into the lungs can trigger pneumonia.

Immune cells containing oily droplets have been found in the lungs of some patients. These large cells, called macrophages, are the clean-up crew of the immune system. University of Utah doctors think this could be a marker for vaping injury. They wrote up their findings about six patients in the New England Journal of Medicine.

What else is in vape liquids?

Most e-cigarettes contain colourless, flavourless chemicals such as propylene glycol and vegetable glycerine, which create an inhalable vapour when heated. The chemicals are considered safe as food additives but their long-term effects when inhaled have not been studied.