Don't panic, but scientists have stumbled across a new substance that may be the deadliest known to man.
A new variant of botulinum toxin, "type H" is so dangerous that researchers have decided to withhold publishing information about it, over concern it could be used as a bioweapon.
New Scientist reported that inhaling just 13 billionths of a gram of the stuff, or an injection of just 2 billionths of a gram, could kill an adult. Yikes.
"This is not the usual process for publishing manuscripts," Dr. David Hooper, an editor at the Journal of Infectious Diseases, told NPR. "We thought in this case an exception was appropriate."
Clostridium botulinum, the bacterium that produces the toxic protein, is found in soil. Once ingested, the protein acts as a neurotoxin and can cause a life-threatening paralytic illness known as botulism.
C. botulinum has long been known to produce the highly dangerous toxins, giving scientists time to develop antitoxins with which to treat them. But H type, the first new botulinum protein discovered in more than 40 years, is untreatable.
Fortunately, the likelihood of an average person randomly encountering the new toxin "is exceedingly small," Hooper told The Huffington Post via email.
Dr. David A. Relman, a professor of medicine at Stanford, wrote in an editorial commentary accompanying the initial report, "Until [a type H] antitoxin can be created, shown to be effective, and deployed, both the strain itself and the [DNA] sequence of this toxin ... pose serious risks to public health because of the unusually severe, widespread harm that could result from misuse of either."
Seven other known strains of the bacterium, labeled after the first seven letters of the alphabet, A - G, are treatable, and only four of them -- A, B, E, and F -- are actually toxic to humans. Of course, C. botulinum also has useful applications, ranging from neuromuscular treatments to Botox for skin wrinkles.
This story has been updated with comment from Dr. David Hooper.