10 Deadly Agents the CDC Works With

Clostridium Botulinum Toxin
A close-up of Clostridium botulinum © Visuals Unlimited/Corbis

Medical advances over the past half-century have dropped botulism's one-in-two kill rate down to 3-5 percent, but the nerve toxin produced by Clostridium botulinum bacteria (and sometimes strains of Clostridium butyricum and Clostridium baratii) is still one nasty customer.

Found naturally in soil and inside homes on floors, carpet and countertops, the bacteria usually makes news through a health emergency involving the foodborne variety. But there are four other types of botulism, including toxins arising from botulism-infected wounds, infant-swallowed bacteria, rare adult intestinal colonization or an overdose associated with therapeutic or cosmetic uses like Botox [source: LDHH]. In the U.S., around 145 botulism cases are reported annually, breaking down as 15 percent foodborne (sometimes linked to home canning), 65 percent infant and 20 percent wound (linked to injecting black-tar heroin). Because honey sometimes contains the bacteria, authorities recommend not feeding it to children under 12 months old [source: CDC].

Symptoms of foodborne botulism usually kick off around 18-36 hours after consumption, and present as blurred and/or double vision, drooping eyelids, slurred speech, dry mouth and difficulty swallowing. Infant botulism reveals itself through lethargy, weak crying, poor muscle tone, constipation and a tendency to not feed well. If untreated, both types result in muscle paralysis symptoms that spread to respiratory muscles, arms, legs and torso, ending in death from respiratory failure.

Botulism is hard to diagnose but treatable with an antitoxin. In foodborne cases, an enema or induced vomiting might also be in order, while wound bacteria might require a course of antibiotics. Even for survivors, though, respiratory failure can mean weeks or months spent on a respirator. Recovery can take weeks, and weakness can last for years afterward.