1 / 63

Biologic Disasters

Biologic Disasters. Bruce Friedberg, MD Department of Emergency Medicine, John Muir Medical Center- Concord Campus Disaster Preparedness Committee. Objectives. Review of most likely agents Clinical signs and symptoms Management review Treatments Infection control

erica-oneil
Télécharger la présentation

Biologic Disasters

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Biologic Disasters Bruce Friedberg, MD Department of Emergency Medicine, John Muir Medical Center- Concord Campus Disaster Preparedness Committee

  2. Objectives • Review of most likely agents • Clinical signs and symptoms • Management review • Treatments • Infection control • Post-exposure prophylaxis • Vaccinations available

  3. Four AM in the ED • 36 year old male presents with fevers and chills, non-productive cough and nausea • Physical exam reveals a well developed male in a Rolling Stones tee shirt • VSS except for a fever of 100.4°, physical exam is otherwise normal • CBC shows mild elevation in WBC, Electrolytes are normal • Patient is hydrated with one liter of NS and discharged with a DX of “Viral Syndrome”

  4. Four AM in the ED • While getting ready to discharge the patient, the nurse finds he is now SOB, with a fever of 104° • Upon returning from this CXR he now has hemoptosis • Rapid progression into shock and is declared dead at 7 am. • The nurse tells you that 25 new patients are in triage with viral symptoms

  5. Is this a Bioterrorism attack?

  6. Epidemiology • Clues suggesting a bioweapon release • Large numbers present at once (epidemic) • Previously healthy persons affected • High morbidity and mortality • Unusual syndrome or pathogen for region or season • Recent terrorist claims or activity • Unexplained epizootic of dead, sick animals

  7. Bioterrorism: Defined • The intentional or threatened use of bacteria, viruses, fungi or toxins to create panic, death or disease. • Purpose • Creating fear • Illness • Death • Disruption of social and economic infrastructure

  8. Our Role • High level of suspicion • Hoofbeats could be a zebra • Disease Surveillance • hospitals will likely be the 1st with the ability to recognize an attack- We are the first line of defense • Recognize typical BT disease syndromes • Know treatment/prophylaxis of BT agents • Know how to report suspected BT cases • Help protect your facility from contamination • Will often require a decontamination washing. • “Code Orange” used for multiple patients.

  9. Why Bioterrorism Agents? • Inexpensive $ • $2000 typical conventional weapon • $1 biologic agent (50% casualties/km2) • Many casualties with minimal planning • Invisible, mimic several common illnesses • Long incubation periods allow escape time for perpetrators • Easily procured

  10. CDC Threat Classification • Class A agents: most severe potential for widespread illness and death • Easily disseminated or transmitted from person to person • High mortality rates • Easily weaponized • Class B agents: less potential • Class C agents: future threats

  11. Terrorist Dissemination Methods • Aerosol likely route for most agents • Easiest to disperse • Highest number of people exposed • Most contagious route of infection • Food / Waterborne less likely • Only effective for some agents

  12. Category A Diseases • Anthrax (Bacillus anthracis) • Smallpox (variola virus) • Plague (Yersinia pestis) • Tularemia (Francisella tularensis) • Botulism (botulinum toxin) • Viral Hemorrhagic Fever

  13. Anthrax Bacillus anthracis

  14. Anthrax • 2001(fall)- anthrax mailings • NBC news, Sen. Tom Daschle • 22 total cases/ 11 inhalation/ 5 deaths

  15. Anthrax: info • Cutaneous • Gastrointestinal (rare) • Inhalation • Spores are Odorless/Invisible • Likely dissemination route: Aerosolization

  16. Cutaneous anthrax • 2000 cases annually (worldwide) • Transmitted from Herbivores • Skin is exposed to spores • Painless, pruritic papule develops • “Painless” black eschar follows • 1-14 day latent period • Mortality: 20%, if untreated • Readily responds to Ciprofloxacin

  17. Inhalation anthrax: clinical • 18 cases in US between 1900-1976 • Follows inhalation of spores • Possible sixty day delay in symptoms • Estimated 3 million deaths from 100 kg release (spores can travel airborne for 60 miles) • During fall 2001 “mailings” • 45% mortality • 4 day latent period

  18. Inhalation anthrax: clinical • Initial sxs (hours to days): • Malaise, drenching sweats • Low-grade fever • Non-productive cough • Nausea/ vomiting • Terminal sxs (usually hours) • abrupt dyspnea, stridor, cyanosis • Rapid progression to shock and death

  19. Inhalational anthrax: clinical • CXR (10/11 in 2001 mailings were abnormal): • Hemorrhagic mediastinitis with widened mediastinum on CXR • Peripheral Blood smear shows Gram-positive bacilli • Aerobic Blood culture shows growth of large, gram-positive bacilli

  20. Anthrax: treatment • Infection Control • Standard precautions • If cutaneous wear gloves • Not transmitted from person to person • Give Antibiotics Early • Ciprofloxacin • Doxycycline

  21. Anthrax: treatment • All post-exposure contacts should be treated for 60 days • Ciprofloxacin • Alternate: doxycycline • Vaccine (developed in 1970s) • Used by military

  22. Smallpox Orthopoxvirus (variola species)

  23. Smallpox: info • One of highest-threat bioterrorism agents • High case fatality rate • Lack of specific therapy • Routine US vaccines stopped in 1972 • Herd immunity no longer present • Likely dissemination route: Aerosolization or human carriers

  24. Small pox: info • 12- 14 day incubation period • Most infective during initial rash period • Less infective after crusting of lesions

  25. Smallpox vs Varicella 14-21 day incubation Minimal prodromal Rapid development of rash Centripetal: seldom on soles and plams Asynchronous lesions- successive crops • 12-14 day incubation • Prodromal symptoms • Slow development of rash • Centrifugal: greatest concentration of lesions on face and extremities • Synchronous lesions

  26. Smallpox vs Varicella

  27. Smallpox: treatment • Supportive only • Infection control • Pt isolation • Standard, Contact & Airborne precautions (N-95 mask recommended) • Immunized individuals should be protected • Antiviral agents not currently recommended

  28. Smallpox: Prophylaxis • Vaccine within 4 days of exposure can lessen severity of infection • Contraindicated in immunocompromised and pts with eczema • “there is enough smallpox vaccine to vaccinate every person in the United States in the event of a smallpox emergency” • Vaccinia immune globulin (VIG) • Within 2-3 days of exposure • Consider for those with contraindications to the vaccine

  29. Botulinum Toxin Clostridium botulinum

  30. Botulism toxin: info • Most poisonous substance known • Occurs naturally in soil (odorless, colorless, tasteless) • Most cases from contaminated undercooked meat (inactivated if >85 C for 5 minutes) • Toxin has neuroparalytic effects • Toxin irreversibly binds to acetylcholine receptors • Likely dissemination route: • Contamination of food or Aerosolization

  31. Botulism: info • Mortality: • Treated = < 5% • Untreated = up to 60% • Diagnosis is CLINICAL • Incubation of 2 hours to 8 days • Many casualties will require long term respiratory support • Confirmatory testing is slow (only at CDC and 20 other public health sites)

  32. Botulism: clinical • Afebrile • Descending flaccid paralysis • Bulbar deficits initially • Four “D’s” • Diplopia • Dysarthria • Dilated pupils • Dysphagia

  33. Botulism: treatment • Supportive care • Respiratory support could be for months • new motor axons must grow to paralyzed areas • Antitoxin (available only from CDC) • May prevent spread of paralysis, BUT does not reverse paralysis • Infection Control • Standard precautions

  34. Botulism: prevention • No effective post exposure prophylaxis • +/- Antitoxin • Vaccine • DOD pentavalent toxoid is available • Used for last 30 years in lab workers

  35. Plague Yersinia pestis

  36. Plague: info • The “Black Death” has caused more fear and terror than perhaps any other infectious disease in history • It has laid claim to at least 200 million lives • Most human cases are from bites from infected fleas who have had a blood feed from an infected rodent • Human to human transmission occurs only in pneumonic plague from direct inhalation • Likely dissemination route: Aerosolization

  37. Plague • Bubonic • Septicemic • Pneumonic

  38. Plague: clinical • Usually present 2-8 days after exposure • Sudden onset of fever, chills, weakness +/-acutely swollen painful lymph nodes • Swollen lymph nodes = “Buboes” • possibly suppurative

  39. Bubonic and septicemic plague: clinical Symptoms + Buboes present Bubonic plague Symptoms without Buboes Septicemic plague -gram-negative sepsis -DIC

  40. Pneumonic Plague: clinical • Approaches 100% fatality rate (untreated) • Highly contagious • Within 24 hours of exposure: • High fever • Vomiting and abdominal pain • Cough with bloody sputum • DIC

  41. Pneumonic Plague: clinical • DX with sputum secretions/ Gram stain & culture

  42. Plague: treatment • Infection Control • Standard and droplet precautions (if pneumonic plague suspected) • Antibiotics recommended (for 10 days) • Start treatment prior to ID (delay can decrease survival) • Streptomycin (reduces mortality to 5-14%) • Gentamicin, Ciprofloxacin,Doxycycline, Chloramphenicol

  43. Plague: prevention • Post exposure prophylaxis: • Treat with antibiotics for seven days • No vaccine is currently available (previously used in military)

  44. Tularemia Francisella tularensis

  45. Tularemia: info • Infection occurs naturally from bites by infected arthropods, handling infectious animal tissues, contact with or ingestion of contaminated food, water, or soil and inhalation of infective aerosols • No person to person transmission • Survives for weeks in water, moist soil, straw, and decaying animal carcasses • The signs and symptoms people develop depend on how they are exposed to tularemia

  46. Tularemia- clinical forms • Ulceroglandular • Pleuropneumonitis • Oropharyngeal • Oculoglandular • Septicemic

  47. Tularemia: clinical • 1-14 day incubation • If inhaled, symptoms can include abrupt onset of fever, chills, headache, muscle aches, joint pain, dry cough, and progressive weakness • One of the most infectious pathogenic bacteria known. • Inhalation of as few as 10 organisms can cause disease. • Likely dissemination route: Aerosolization

  48. Tularemia- treatment • Infection Control • Contact and Airborne Precautions • Use Antibiotics (14-21 days) • Streptomycin • Gentamicin • Ciprofloxacin

  49. Tularemia- prevention • Post-exposure prophylaxis • Doxycycline • Ciprofloxacin • Tetracycline • Vaccine available • Live attenuated vaccine (under FDA review)

More Related