Anthrax gained notoriety a week after the terrorist attacks of Sept. 11, 2001, when a powdered form of the bacteria was mailed to two U.S. Senators and several media outlets, killing five and infecting 17 more.
But if you dig up a patch of ground in Oklahoma, you’ll almost certainly find anthrax spores. “It’s everywhere,” said Oklahoma Medical Research Foundation scientist Mark Coggeshall, Ph.D. “We’re walking on anthrax every day.”
So why don’t we all contract deadly respiratory infections?
The answer, said Coggeshall, is that “the anthrax in the ground is dormant.”
Dormant anthrax is not harmless, but because so much of it is needed to cause illness, people who dig ditches, frequently garden, or otherwise work in the ground aren’t in danger.
“The biggest risk for exposure is for people who work with animal skins and hair, because the animals eat the bacteria and it gets on their hides and fur. It was originally called ‘wool sorters disease,’” Coggeshall said. “These days, people working with animal hides are routinely vaccinated. And as long as they’re in a ventilated area, the risks are minimal.”
The 2001 letter attacks and fears of bioterrorism prompted renewed interest in studying anthrax. Since 2004, Coggeshall and a team of researchers from OMRF have received a research grant from the National Institute of Allergy and Infectious Diseases to study the natural immune response to anthrax.
Infection begins when humans come into contact with sufficient amounts of the bacteria through touch or when it’s ingested through contaminated meat. The most deadly anthrax infections come when humans breathe in the bacteria.
Inhalation anthrax kills because it’s “insidious,” Coggeshall said. “You don’t know you have it until it’s too late.”
Once inside the body, anthrax produces toxins that attack the immune system by destroying key defensive cells in the human immune system. The disease can prove fatal in just a few days.
“We still don’t completely understand why the disease is so deadly,” said Coggeshall. “We want to learn everything about anthrax bacteria: how they get from the lung to the blood, what happens when they’re in the blood, and how to produce and stop the bacteria with the right antibodies.”
Still, he said, outside of the bioterrorism realm, anthrax does not pose a threat to most of us. “There’s no need to worry, even if you plan on spending the weekend digging in the dirt,” said Coggeshall.