Botulinum toxin, produced by Clostridium botulinum bacteria, is the most potent biological toxin known to exist on Earth. The toxin causes botulism, a severe muscle-paralyzing, potentially fatal disease, characteristics that increase its likelihood as a potential bioweapon.
And while the U.S. government stockpiles antitoxins to treat the known toxin types, if a botulism terrorist attack were unleashed, the problem could get beyond our control rather quickly, experts told Homeland Preparedness News.
“There is a lot of controversy around botulism being used as a bioweapon and my major concern — and why this hasn’t happened is interesting and I’m not sure why, nor do I want it to happen — but I’m concerned that it could be used in the food supply,” said Dr. Eric A. Johnson, professor of bacteriology in the University of Wisconsin-Madison’s (UW-M) Department of Bacteriology.
To date, the United States hasn’t reported any such intentional incidents, “but the food supply is vulnerable if somebody knows what they’re doing. It’s not difficult,” said Johnson, who has been involved in federal programs for bioterrorism preparedness and currently sits on two review panels for the National Institutes of Health’s National Institute of Allergy and Infectious Diseases.
Johnson is considered one of the world’s foremost experts on botulism. As a researcher at UW-M’s Food Research Institute in the College of Agricultural and Life Sciences, Johnson’s lab has studied Clostridium botulinum and its neurotoxins for 25 years and earned Category A Select Agent approval, meaning the high-security lab is an elite, one-of-few U.S. labs with the expertise and ability to conduct comprehensive botulism studies. Johnson has been widely published and holds 27 patents from his research.
Botulinum spores are naturally abundant in soil across the globe and their toxins can be present in contaminated foods. Botulism is different from other agents, Johnson explained, because it’s “extraordinarily stable in the gastrointestinal tract.”
As a potentially fatal paralytic disease, patients exposed to botulinum toxin require immediate hospitalization. There is only a few hours to administer an antitoxin, and often people with botulism will need support through mechanical ventilation.
If a large outbreak occurred, Johnson said the only way to keep people alive would be via respirators “and most are occupied by the elderly. So for a small outbreak of say two to 20 people, we could handle the nursing care and incubation, but if a large outbreak occurred, it could be a disaster.”
“We’ve been lucky so far this has not happened on a large scale,” he said in an interview.
The toxin is classified by the Centers for Disease Control and Prevention (CDC) as a Category A bioterrorism agent for which governments prepare and stockpile treatments, said Laura Saward, senior vice president of Antibody Therapeutics at Emergent BioSolutions Inc.
The Gaithersburg, Maryland-based biotechnology company produces the only treatment for botulism that covers all seven serotypes and is approved by the U.S. Food and Drug Administration and Health Canada, she said.
“Emergent’s Botulinum Anti-Toxin or BAT is stockpiled by the U.S. government and has been purchased by other countries for use in the event of an emergency,” Saward said in an interview.
The large stockpiles of antitoxin make it “pretty evident there’s going to be an outbreak and we could administer BAT; it’s safe and effective,” Johnson said.
But the problem is that once the toxin gets in the bloodstream and in the nerves, there’s no antidote, he said, except to administer respiratory care to improve a person’s breathing. “So the answer is yes we have preparedness, but it could be better,” Johnson said.
Ukrainians recently have experienced such trauma.
“Based on reports, the majority of cases in Ukraine have been linked to dried fish — commercial and home prepared — and some cases have been linked to home-prepared stew,” Saward said.
“There has been a lack of antitoxin in the country since 2014 when the registration for the antitoxin that was being used in Ukraine expired,” she said.
Typically, these types of natural outbreaks could happen anywhere as the bacteria that make botulinum toxin are found naturally around the globe, explained Saward, who is also an adjunct professor of medical microbiology and infectious disease at the University of Manitoba.
“It is rare for these bacteria to make people sick, however when it does occur, botulism constitutes a medical emergency,” she said. “Over the last months, Ukraine has faced an outbreak of botulism — 76 cases recorded since the beginning of the year, eight of them fatal.”
Due to the potent nature of the botulinum toxin, treatment at the earliest possible time is important, she said.
“Patients with suspected exposure should seek medical assessment as soon as possible. The U.S. government has stockpiled botulinum antitoxin that is distributed through the CDC to provide this life-saving therapy to patients in need,” she said.
Saward added that Emergent BioSolutions is prepared to respond to public health emergencies such as the botulism outbreak in Ukraine.
“One of our strengths is working with non-governmental organizations, governments, and Ministries of Health and Defense to support their preparedness needs to protect the population from biological threats like botulism and anthrax, as well as chemical threats,” she said.
An outbreak on a mass scale “would be a difficult situation to handle,” added Johnson.