Prions could be source for new bioweapons

Prions, the cause of neurodegenerative disorders like mad cow disease, may be in their most lethal form when sprayed into the air, raising fears that they may be used as bioweapons.

According to a new study, inhaled prions can be up to 100 percent lethal in mice. The discovery does not signify the finding of a new public health threat, but it is a surprise to scientists who study prion-based diseases. It also calls safety rules for laboratories and slaughterhouses into effect, according to Wired.

“Common knowledge is that prions aren’t airborne and can’t cause infection that way,” neuropathologist Adriano Aguzzi said, according to Wired. “We were totally surprised and also a bit frightened at how efficient [airborne infections] were.”

Aguzzi works with the University Hospital of Zurich and is the co-author of the study, which appears in PLoS pathogens.

Most infections are caused by bacteria or viruses, which use genes to replicate. Prions are another form of disease that was discovered in 1982. They are made of misfolded proteins and resemble normal proteins found in the brain and other nervous tissue. There abnormal shape causes healthy proteins to change into long fibrils that kill cells.

“Prions are like an enemy within, the alien in some B-movie that transforms people to an evil version,” protein biologist Edward Hoover of Colorado State University said, according to Wired. “The immune system doesn’t see them coming.”

There are only five known human prion-based diseases including Creutzfeldt-Jakob disease, and six non-human diseases, including mad cow disease, which can jump into humans through contaminated meat.

Until now, there was only inconclusive evidence that pointed to the airborne transmission of prions. Because prion disease is so limited in humans, it is unlikely that naturally occurring airborne prions pose a significant threat to most people.