Reports of the mysterious vaping-related illness are continuing to spring up across the US. But with the death toll still rising, health authorities remain remarkably uncertain about what’s causing the outbreak. 

According to the latest stats from the Centers for Disease Control and Prevention (CDC), there have been 1,888 reported cases of vaping disease from 49 states (all states bar Alaska) and 37 deaths confirmed across 24 states. Despite increasing awareness of the illness, the rate of cases being reported appears to be picking up pace, with 284 new cases being reported within the last week alone. 

However, a new study published this week – ominously titled "EVALI: The Tip of the Iceberg" – has warned that these numbers are likely to be much higher in reality, as doctors are still learning to recognize the symptoms of this emerging condition. 

Known as EVALI, symptoms typically start with a cough, wheezing, shortness of breath, chest pain, and nausea. Eventually, a fever, fatigue, and weight loss can develop too. Researchers studying the condition have noted that the lung damage seen in affected people closely resembles a chemical burn.

The cause of the disease has remained uncertain since the first reports in April 2019. However, the CDC has recently published a report confirming EVALI is linked to vaping products containing tetrahydrocannabinol (THC) bought on the black market, just as other scientific studies have suggested.

In particular, researchers noted that many patients have bought THC-containing products labeled as “Dank Vapes” online. It’s thought that Dank Vapes is not a single centralized company, but rather a brand name used by multiple unregulated operators. THC itself is not thought to be the problem. Some reports have found many of the used THC-infused vape liquids appear to have been cut with a thickening agent, vitamin E acetate, which could be causing the lung injuries. 

Up to 70 percent of patients with EVALI are male, a significant number of which are young men under the age of 25. Robert R Redfield, director of the CDC, recently suggested this link is being used by researchers as a lead to find an overall cause of EVALI.

Until the source of the outbreak is identified, the CDC and FDA have recommended all people avoid vaping altogether. On the other hand, some experts believe this guidance is overzealous, arguing that the issue should be treated in a similar fashion to a food contamination outbreak, rather than suggesting it's a fundamental problem with vaping itself. 

“Authorities who are reacting to these cases by advising no one to vape are by default sending the message to people who have quit smoking through vaping that they should return to tobacco. This is misleading and potentially irresponsible,” Linda Bauld, a professor of Public Health at the University of Edinburgh, said in a statement.