507 Bacterial Pathogenesis Botulism 507 Bacterial Pathogenesis

History Disease – botulism Agent – botulinum toxin Source of toxin - Clostridium botulinum Discovered in 1895 WuDunn S, Miller J, Broad WJ. How Japan germ terror alerted world. New York Times. May 26, 1998:A1, A10. Tucker JB, ed. Toxic Terror: Assessing the Terrorist Use of Chemical and Biological Weapons. Cambridge, Mass: MIT Press; 2000.

Epidemiology All ages and genders equally susceptible Mortality 25% prior to 1960 6% during 1990’s

Epidemiology Incubation period Depends on inoculated dose Inhalational 12-18 hours in primate studies 72 hours in 3 known inhalational cases True incubation period is unknown Foodborne 6 hours to 8 days Wound 7.5 days (range 4-18 days) after injury Schantz EJ, Johnson EA. Properties and use of botulinum toxin and other microbial neurotoxins in medicine. Microbiol Rev. 1992;56:80-99. Franz DR, Pitt LM, Clayton MA, Hanes MA, Rose KJ. Efficacy of prophylactic and therapeutic administration of antitoxin for inhalation botulism. In: DasGupta BR, ed. Botulinum and Tetanus Neurotoxins: Neurotransmission and Biomedical Aspects. New York, NY: Plenum Press; 1993:473-476. Herrero BA, Ecklung AE, Streett CS, Ford DF, King JK. Experimental botulism in monkeys: a clinical pathological study. Exp Mol Pathol. 1967;6:84-95. Scott AB, Suzuki D. Systemic toxicity of botulinum toxin by intramuscular injection in the monkey. Mov Disord. 1988;3:333-335.

Microbiology C. Botulinum Gram-positive obligate anaerobic bacillus Spore-forming Produces botulinum toxin Heat sensitive as bacillus Prefers low acid environment Inglesby, T. The Washington Post Wednesday, December 9, 1998; Page H01

Microbiology C. Botulinum spores Ubiquitous Soil Airborne dust Surfaces of raw fruits and vegetables Seafood WuDunn S, Miller J, Broad WJ. How Japan germ terror alerted world. New York Times. May 26, 1998:A1, A10. Tucker JB, ed. Toxic Terror: Assessing the Terrorist Use of Chemical and Biological Weapons. Cambridge, Mass: MIT Press; 2000.

Microbiology Botulinum toxins Consist of light and heavy chains Light chain – zinc endopeptidase The bioactive component Environmental survival Inactivated by heat > 85ºC for 5 min pH <4.5

Microbiology Toxin Classification All have same clinical effect Types A-G, antigenically distinct Type A- 54%, Type B- 15%, Type E- 27% Type A- Western U.S., Type B- Eastern Types C, D reported in animals only Type G in soil samples only Humans likely susceptible to all types

Pathogenesis Possible routes of exposure Inhalation of toxin (in a biological attack) Food or water toxin contamination Wound infected with C. Botulinum Ingestion of C. botulinum

Pathogenesis crystalline type A toxin 0.09-0.15 g given iv or im Estimated lethal human dose crystalline type A toxin 0.09-0.15 g given iv or im 0.70-0.90 g inhalationally 70 g given po Schantz EJ, Johnson EA. Properties and use of botulinum toxin and other microbial neurotoxins in medicine. Microbiol Rev. 1992;56:80-99. Franz DR, Pitt LM, Clayton MA, Hanes MA, Rose KJ. Efficacy of prophylactic and therapeutic administration of antitoxin for inhalation botulism. In: DasGupta BR, ed. Botulinum and Tetanus Neurotoxins: Neurotransmission and Biomedical Aspects. New York, NY: Plenum Press; 1993:473-476. Herrero BA, Ecklung AE, Streett CS, Ford DF, King JK. Experimental botulism in monkeys: a clinical pathological study. Exp Mol Pathol. 1967;6:84-95. Scott AB, Suzuki D. Systemic toxicity of botulinum toxin by intramuscular injection in the monkey. Mov Disord. 1988;3:333-335.

Pathogenesis Toxin must enter body Does not penetrate intact skin Direct toxin absorption from mucosal surface Gut – foodborne Lungs – inhalational Via toxin produced by infection with C.botulinum Skin breaks – wound botulism after trauma, IV drugs Gut – intestinal botulism Would not be seen in BT event, as toxin would be used Does not penetrate intact skin Schantz EJ, Johnson EA. Properties and use of botulinum toxin and other microbial neurotoxins in medicine. Microbiol Rev. 1992;56:80-99. Franz DR, Pitt LM, Clayton MA, Hanes MA, Rose KJ. Efficacy of prophylactic and therapeutic administration of antitoxin for inhalation botulism. In: DasGupta BR, ed. Botulinum and Tetanus Neurotoxins: Neurotransmission and Biomedical Aspects. New York, NY: Plenum Press; 1993:473-476. Herrero BA, Ecklung AE, Streett CS, Ford DF, King JK. Experimental botulism in monkeys: a clinical pathological study. Exp Mol Pathol. 1967;6:84-95. Scott AB, Suzuki D. Systemic toxicity of botulinum toxin by intramuscular injection in the monkey. Mov Disord. 1988;3:333-335.

Pathogenesis Wound Botulism from a heroin user. Jermann M, Hiersemenzel LP, Waespe W Drug-dependent patient with multiple cutaneous abscesses and wound botulism Schweiz Med Wochenschr 1999;129:1467

Pathogenesis All forms of disease lead to same process Toxin absorbed into bloodstream Irreversibly binds peripheral cholinergic synapses Cleaves fusion proteins used by neuronal vesicles to release acetylcholine into neuromuscular junction Blocks Acetylcholine release permanently Results in paralysis of that muscle Reinnervation via regeneration of axon twigs Takes weeks to months

Pathogenesis Synaptic vesicle: stores various neurotransmitters that are released at a synapse. SNARE proteins: Soluble N-ethylmaleimide-sensitive factor activating protein receptor (SNARE) proteins, establish tight membrane contact, formation of a scaffolding on which to build the machine, binding of lipid surfaces and many others. JAMA. 2001;285:1059-1070

Pathogenesis JAMA. 2001;285:1059-1070

Clinical Features Symptoms All forms same neuro symptoms Diplopia / blurred vision Ptosis (drooping or falling of the eyelid) Slurred speech Dysphagia / dry mouth Muscle weakness

Clinical Features Infant botulism specifically Appears lethargic Feeds poorly Constipated Weak cry Poor muscle tone

Clinical Features Classic Triad Bulbar palsies summarized as "4 Ds" Symmetric, descending flaccid paralysis with prominent bulbar palsies Afebrile (having no fever) Clear sensorium Bulbar palsies summarized as "4 Ds" Diplopia, dysarthria (speech disorder), dysphonia (impairment in ability to produce voice sound), dysphagia (dry mouth)

Clinical Features Symptom progression Descending paralysis Lose head control Lose gag – require intubation Lose diaphragm – mechanical ventilation Loss of deep tendon reflexes

Dilated or unreactive pupils Clinical Features Gastrointestinal/ Urinary Neurologic Muscular Nausea Dry Mouth Symmetrical skeletal Muscle weakness Vomiting Blurry vision Respiratory muscle paralysis Diarrhea Diplopia Fatigue Abdominal Pain Dilated or unreactive pupils Dyspnea Intestinal ileus Dysphagia Urinary retention Decreased gag reflex

Clinical Features 4 clinical forms of botulism Food-borne (first described in 1897) Wound (1943) Infant (1976) Indeterminate (1977)

Clinical Features Infant Occurs in children < one year old Ingests spores, grows in bowel & release toxin Intestinal colonization of organisms Normal intestinal flora not developed

Clinical Features Indeterminate No specific food or wound source identified Similar to infant but occurs only in adults Risk factor: surgical alterations of the GI tract and/or antibiotic therapy Leads to colonization

Diagnosis Clinical diagnosis Diagnostic tests help confirm Toxin neutralization mouse bioassay Serum, stool, or suspect foods Infant botulism C. botulinum organism or toxin in feces

Diagnosis What to do at first suspicion of a case Immediately notify public health department Acquire therapeutic antitoxin Send samples for diagnostic testing Serum, vomit, gastric aspirate, suspect food, stool Collect serum before antitoxin given If enema required, use sterile water Refrigerate samples and suspect foods Get medication list to rule out anticholinesterases

Diagnosis Confirmation Mouse Bioassay Culture Takes 1-4 days Available only at CDC and state public health labs Mouse Bioassay Type-specific antitoxin protects vs. toxin in sample The assay can detect at minimal 0.03ng of toxin. Culture Fecal and gastric specimens cultured anaerobically Results in 7 to 10 days

Diagnosis Differential diagnosis Unique features to help in diagnosis Guillain-Barre, myasthenia gravis Unique features to help in diagnosis Disproportionate cranial nerve palsies More hyptonia in facial muscles than below neck Lack of sensory changes

Table adopted from: Botulinum Toxin as a Biological Weapon (JAMA. 2001;285:1059-1070)

Treatment Supportive care Enteral tube feeding or parenteral nutrition (via veins) Mechanical ventilation Treatment of secondary infections Avoid aminoglycosides and clindamycin Worsens neuromuscular blockade

Treatment Passive immunization - equine antitoxin Antibodies to Types A, B and E toxins Binds and inactivates circulating toxin Stops further damage but doesn’t reverse Administer ASAP for best outcome Dose per package insert Heptavalent antitoxin Investigational Effective against all toxins

Treatment Antitoxin action Antitoxin adverse effects Food-borne botulism Neutralizing antibody levels exceed toxin levels Single dose adequate Large exposure (e.g. biological weapon) can confirm adequacy of neutralization recheck toxin levels after treatment Antitoxin adverse effects Serum sickness (2-9%), anaphylaxis (2%)

Treatment Recovery takes weeks Until motor axon twigs regenerate Special groups - same treatment strategy Children Pregnant women Immunocompromised

Prevention Natural disease Boil home-canned foods 10 minutes Follow USDA instructions on home-canning Restrict honey from < 1 year old Seek medical care for wounds Avoid injectable street drugs

Prevention Vaccine Botulinum pentavalent toxoid Not available to general public Limited supply provided by CDC In use for laboratory workers, military Protects vs. types A-E Long-lasting immunity Prohibits future therapeutic use of toxin Onset too slow to be effective PEP

Infection Control Standard precautions only No person-to-person transmission

Decontamination Heat all food 85ºC x 5 min Aerosolized toxin viability Inactivate by 2 days in optimal conditions Re-aerosolization a theoretical concern Mask over the face may be protective Exposed clothing and surfaces Wash with 1:10 hypochlorite solution