Infectious Disease: Tetanus Rabies Occupational Exposure Standard Precautions

1. Infectious Disease:TetanusRabiesOccupational ExposureStandard Precautions Thomas Vu Resident Weekly Conference 09/25/2019

2. Tetanus • Intro • Pathophysiology • Symptoms • Treatment • Vaccination Post Exposure

3. Tetanus - Intro • 1 million cases per year worldwide, uncommon in US • Mortality 20-30% • **Reportable disease • US 2001-2008: 233 cases • Most = inadequate immunity to disease (young adults, elderly)

4. Tetanus - Pathophysiology • Clostridium tetani – anaerobic G+ rod • Produces 2 exotoxins that invade nervous system • Prevents release of inhibitory neurotransmitters, causes sympathetic overactivity • Spores found abundantly in soil, animal feces • Exposures include contaminated wounds, puncture wounds, lacerations, abrasions, IVDU

6. Quiz 1

7. Tetanus - Pathophysiology Acute Wounds • Puncture • Contaminated • Infected • De-vitalized tissues Other Wounds (less common) • Chronic • Ulcers • Diabetic • Dental Abscess Non Wounds (less common) • Surgical Procedures • Otitis Media • Abortions • Neonatal (umbilical stump)

8. Quiz 2

9. Tetanus - Symptoms • <24hr to >1mo after exposure • Diagnosis = clinical • Resembles Strychinepoisoining Acute onset of hypertonia and/or painful muscular contractions without other apparent medical causes • Lockjaw, neck • Muscle spasms – trismus, sardonic smile, dysphagia, arm flexion Autonomic changes (2nd week) • Tachycardia, labile hypertension, profuse sweating, hyperpyrexia, urinary excretion Complications: • Rhabdomyolysis, long bone fractures, laryngospasms, respiratory muscle contractions • Prolonged hospitalization (PE, asp pna, sepsis)

10. Quiz 3

11. Tetanus - Treatment • ABCs - mechanical ventilation, sedation, neuromuscular blockade (succinylcholine, vecuronium) • Patients with respiratory compromise • Immunoglobulin + Toxoid • Tetanus Ig 3000-6000 U IM – some around wound site; give before wound debridement; neutralizes circulating toxins; reduces mortality • Toxoid 0.5mL IM prevents further infection; give at presentation + 6wks + 6mos after presentation; give on opposite side of Ig

12. Tetanus - Treatment • Wound debridement • Metronidazole 500mg IV q6 (limited value) • Do NOT give penicillin • Muscle relaxation – Versed (preferred over Lorazepam, Diazepam) • For autonomic dysfunction – Mg, Labetalol, Morphine, Clonidine • Recovery can take weeks-months

13. Quiz 4

17. Tetanus – Vaccination Post Exposure Who gets Tetanus Ig? • Gross Contamination +Unknown vaccination series Who gets Td or Tdap? • Same + Last dose >5years • Clean Contamination + Unknown vaccine series + Last dose > 10 years

19. Quiz

20. Rabies

21. Rabies • Intro • Pathophysiology • Prophylaxis • Clinical Rabies • Diagnosis & Treatment

22. Rabies - Intro • 55,000 people die of rabies annually worldwide • Primarily animal disease • 6000 rabid animals in US reported 2010 • 40,000 postexposure prophylaxis given • 29 human cases in US 2010 (8 contracted in other countries)

23. Rabies - Pathophysiology • Rabies virus from genus Lyssavirus • Replicates in mammalian CNS, transmitted by direct contact, spreads peripherally to animal salivary gland • Encephalitis – gray matter of CNS; eiosinophilic intracellular lesions = highly specific

25. Quiz 5

26. Rabies – Prophylaxis & Post Exposure Care • Pre-Exposure Prophylaxis • activities at high risk of rabies exposure • Post Exposure • Definitely Give Immediately = Skunks, Racoons, Foxes, Bats • Give only if observing animal show signs of clinical rabies = Dogs, Cats, Ferrets • Never give = Squirrels, Hamsters, Guinea Pigs, Chipmunks, Mice, Rabbits

28. Quiz 6

30. Quiz 7

31. Rabies – Prophylaxis & Post Exposure Care • General wound care • Soap + water, irrigation with diluted povidine, iodine • Prophylaxis Regimen • HRIG 20 IU/kg ideal wt • Directly into wound • Rabies Vaccine 4 doses over 14 days • Day 0, 3, 7, 14 • Previously vaccinated = only 0, 3 Give them in separate arms (IG can disable vaccine) • Do NOT deviate – 13 cases rabies documented due to straying from CDC regimen • Side effect of Prophylaxis – Local Effects, (erythema, swelling), HA, N/V, Abd Pain, Myalgias, Dizziness, Serum Sickness-like reaction • Special Population • Pregnancy = safe • Children = same dose for vaccine, Ig is wt based • Travelers = obtain thorough history especially if from areas of rabies epidemic

35. Quiz 8

36. Rabies – Clinical Rabies • Incubation: 20-90 days (reports early as 4 days, late as 6 years) • Prodrome: 2-10d (of symptom onset) malaise, HA, F, N/V • Acute Neuro: 2-7d Anxiety, Agitation, Depression, Hyperventilation, Hydrophobia, Aerophobia, Pharyngeal Spasm, Confusion, Delirium • Coma: 0-14 Hypotension, Hypoventilation, Apnea, Pituitary Dysfunction, Cardiac Arrhythmia, Pneumothorax, Cardiac Arrest

38. Rabies – Diagnosis & Treatment Diagnosis • Consider in unexplained acute, rapidly progressive encephalitis, especially with autonomic instability, **hydrophobia, **aerophobia, dysphagia, neuro ssx • DDx: Tetanus, polio, GBS, botulism, Transverse myelitis, viral enceph • Ag and Ab testing of serum/CSF/other tissues, but only once sx are evident (not detectable in incubation period) Treatment • Do NOT give steroids • Traditionally no specific therapies have proven beneficial • Previously 100% mortality • Milwaukee Protocol – chemically induced coma: ketamine+midaz + ribavirin+ amantadine • Showed 5 survivors out of 36 • Controversial

39. Quiz

40. Occupational Exposure • Portals for Exposure • Hep B, Hep C, HIV • Other Common Exposures

41. Occupational Exposure – Portals of Exposure • Percutaneous • Mucous Membrane • Respiratory • Dermal

42. Quiz

43. Occupational Exposure – Hep B, Hep C, HIV

44. Occupational Exposure – Hep B, Hep C, HIV • Wound care • Irrigate, wash • Obtain relevant history • Circumstances, source, vaccination of exposed • Labs • Both exposed and source (using consent when required)

46. Do not use antiseptic

47. Quiz 9