بسم الله الرحمن الرحيم

1. بسم الله الرحمن الرحيم BIODEFENSE Epidemiology of Botulism Shahid Beheshti University of medical sciences, April 2005 By: Vahdani P. MD. MPH, Hatami H. MD. MPH

2. Definition • Disease – botulism • Agent – botulinum toxin • Source of toxin - Clostridium botulinum بوتوليسم نوعي بيماري عفوني همراه با فلج شل پايين رونده است كه در اثر توكسين بوتولينــوم (Botulinum) توليد شده بوسيله گونه هـــاي كلوستريديوم بوتولينوم، ايجاد مي شود

3. History • Therapeutic use of botulinum toxin • FDA approved for neuromuscular disorders • Blepharospasm • Strabismus • Torticollis • Many other unapproved uses • Packaged in dilute preparations • Not feasible to use licensed toxin for weapon

4. Therapeutic Uses of Botulism Toxin • Focal dystonias - involuntary, sustained, or spasmodic patterned muscle activity • Spasticity - velocity-dependent increase in muscle tone • Nondystonic disorders of involuntary muscle activity • Strabismus (disorder of conjugate eye movement) and nystagmus • Disorders of localized muscle spasms and pain • Smooth muscle hyperactive disorders • Cosmetic use • Sweating disorders

5. Bioweapon Potential • Known unsuccessful uses as weapon • 1990 -1995 aerosol releases by Aum Shinrikyo • Downtown Tokyo, Japan • 3 times at US Military bases in Japan • Weapons Programs • 1930s Japanese fed C.botulinum to prisoners • U.S. produced botulinum toxin during WWII • Soviet Union spliced genome into other bacteria • 1991 Iraq weaponized 19,000L during Persian Gulf War

6. Bioweapon Potential • Botulinum toxin a major threat because: • Extreme potency and lethality • Ease of production • Ease of transport • Need for prolonged intensive care • Top 6 potential biological warfare agents • Listed as Category A agent: High priority

7. Critical Biological Agents Category A • Variola major • Bacillus anthracis • Yersinia pestis • Clostridium botulinum • Francisella tularensis • Ebola hemorrhagic fever • Marburg hemorrhagic fever • Lassa & Junin

8. Bioweapon Potential • Factors suggesting intentional release • Large # cases • Acute flaccid paralysis with bulbar palsies • Unusual botulinum toxin type • Type C, D, F, or G • Type E not acquired from aquatic food • Common geographic factor among cases • No common dietary exposure - Suggests aerosol • Multiple simultaneous outbreaks without common source

9. Bioweapon Potential • Estimated Effect • Most toxic substance known • 1 gram crystalline toxin can kill > 1 million people if dispersed and inhaled evenly • Point source aerosol release • Incapacitate/kill 10% of people downwind within 500 meters

10. Bioweapon Potential • Naturally occurring botulism • Foodborne (preserved or non-preserved) • Wound • Intestinal • Bioterrorism routes of intoxication • Aerosol (inhaled into lungs) • Foodborne • Waterborne ???

11. Bioweapon Potential • Inhalational exposure • One documented accidental outbreak • Germany 1962 • 3 laboratory workers • Exposed to re-aerosolized toxin type A • Confirms that aerosol route is effective means of intoxication

12. Bioweapon Potential • Food-borne botulism • Foods that are higher pH • corn, pepper, carrots, beans, • Contaminated condiments • Commercial foods • Difficult to distinguish intentional

13. Bioweapon Potential • Water-borne botulism • No instances of water-borne botulism have ever been reported • Contamination of water supply is possible • Toxin would be rapidly inactivated by the chlorine used to purify drinking water • Harrison 2005 pp. 1286

14. Bioweapon Potential • Municipal water plants unlikely source • Botulinum toxin inactivated by standard potable water treatments (chlorination, aeration) • Slow turnover time of large-capacity reservoirs • However, in untreated water or beverages the toxin may be stable for several days

15. Epidemiology • U.S. incidence • < 200 annual cases of all forms • Approx 9 annual outbreaks of food-borne • median of 24 cases • Recent trend toward restaurant rather than home-preserved foods • All ages and genders equally susceptible • Mortality • 25% prior to 1960 • 6% during 1990’s

16. Epidemiology وضعيت بيماري در ايران و مطالعات انجام شده مطالعات ده ساله در انستيتو پاستور؟ سروتايپ‌هاي مختلف در ايران؟ آلودگي مواد غذائي مختلف در ايران؟ مطالعات انجام شده در بيمارستان لقمان حكيم تهران؟ مسموميت در قزوين؟ مسموميت در چابهار؟

17. كتاب بوتوليسم و مسموميت غذائي، دكتر پرويز وحداني

18. كتاب بوتوليسم و مسموميت غذائي، دكتر پرويز وحداني

19. 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

20. Microbiology • C. Botulinum • Gram-positive obligate anaerobic bacillus • Spore-forming • Produces botulinum toxin • Heat sensitive as bacillus • Prefers low acid environment

21. Microbiology • C. Botulinum spores • Ubiquitous • Soil • Airborne dust • Surfaces of raw fruits and vegetables • Seafood • Heat resistant, hardy

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

23. 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

24. 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

25. Botulism Toxin Mechanism

26. Pathogenesis • 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

27. Pathogenesis • Toxin must enter body • 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

28. 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

29. Clinical Features Symptoms • All forms same neuro symptoms • Diplopia / blurred vision • Ptosis • Slurred speech • Dysphagia / dry mouth • Muscle weakness

30. Infant Botulism • Most common form in U.S. • Spore ingestion • Germinate then toxin released and colonize large intestine • Infants < 1 year old • 94% < 6 months old • Spores from varied sources • Honey, food, dust, corn syrup

31. Infant Clinical Signs • Constipation • Lethargy • Poor feeding • Weak cry • Bulbar palsies • Failure to thrive

32. Clinical Features • Classic Triad • Symmetric, descending flaccid paralysis with prominent bulbar palsies • Afebrile • Clear sensorium • Bulbar palsies summarized as "4 Ds" • Diplopia, dysarthria, dysphonia, dysphagia

33. Clinical Features Patient at rest, bilateral mild ptosis, disconjugate gaze, symmetric facial muscles. Requested to perform max. smile. Ptosis, disconjugate gaze, mild asymmetric smile.

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

35. Clinical Features

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

37. 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

38. 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

39. 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

40. Diagnosis • What to do at first suspicion of a case • Immediately notify public health dept • 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

41. Diagnosis • Confirmation • 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

42. Diagnosis • Differential diagnosis • Guillain-Barre, myasthenia gravis • Unique features to help in diagnosis • Disproportionate cranial nerve palsies • More hypoxia in facial muscles than below neck • Lack of sensory changes The diagnosis is suspected on clinical grounds and confirmed by a mouse bioassay or toxin immunoassay. HA 2005

43. Botulism Differential Diagnoses • Guillain-Barré syndrome • Myasthenia gravis • Stroke • Tick paralysis • Lambert-Eaton syndrome • Psychiatric illness • Poliomyelitis • Diabetic Complications • Drug intoxication • CNS infection • Overexertion

45. كتاب بيوتروريسم، دكتر حسين حاتمي

46. Treatment • Supportive care • Enteral tube feeding or parenteral nutrition • Mechanical ventilation • Treatment of secondary infections • Avoid aminoglycosides and clindamycin • Worsens neuromuscular blockade

47. ترندلنبرگ معكوس Do not give aminoglycosides and clindamycin

48. Treatment • Passive immunization - equine antitoxin (5000-9000 IU) • 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

49. Treatment • Antitoxin action • 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%)

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