After a lot of talk that e-cigarettes are a much safer alternative to smoking, it turns out that they can also be very harmful, particularly increasing susceptibility to respiratory disease similar to the patterns. For those of you who may not know, e-cigarettes are simply a battery, atomizer, and a cartridge that produce a vapor that can be inhaled by a user, mimicking the effects of a cigarette.
After strong public health campaigns to reduce the number of people smoking due to the detrimental health effects, the number of people who smoke has gone down over the years, though it has been notoriously difficult to quit. Smoking in particular is addictive because of it nicotine content, which is actually equal to the nicotine content of e-cigarettes. Notably, e-cigarettes produce a much lower load of free radicals compared to cigarette smoke, but this amount may still pose a public health threat.
A group of researchers from the Johns Hopkins Bloomberg School of Public Health conducted a study with mice to look at these effects on the progression of respiratory disease. The mice were effectively "smoking" e-cigarettes by inhaling vapor from e-cigarettes in the experimental group or just normal air in the control group. These mice were exposed via nasal drops to bacteria causing pneumonia and sinusitis, a strain of the Influenza A virus, or nothing at all.
Bacterial and viral infections were shown to increase the harmful effects of e-cigarette vapor. The virus was shown to compromise the immune system further and led to increased weight loss and death. This study suggests that e-cigarettes may not be as "safe" as touted by its marketers, particularly when implicated with other infectious agents like viruses. It would be interesting to see the effects of other respiratory viruses on the outcomes of the study in conjunction with e-cigarettes.