Biological Agents and Terrorism

1. Biological Agents and Terrorism

2. Objectives • Learn how to perform an assessment of a biologic agent such as anthrax in a terrorism situation. • Discuss the history of anthrax as a biologic weapon • Recognize various disease presentations of anthrax.

3. Objectives • Discuss the pathogenesis of anthrax • Recognize naturally occurring anthrax presentations versus weaponized anthrax • Learn how to medically manage anthrax infections.

4. Biologic Agent Case • Winter in the Midwest • Typical Year • Many complaints of a runny nose • Many complaints of a cough • Many complaints of a tactile fever

5. Biologic Agent Case • A 40 y/o police officer presents with a fever and muscle aches. He is pale, has a temperature of 102°F. His physical exam and labs are unremarkable so he is discharged and given flu instructions. He says his partner is also ill.

6. Biologic Agent Case • Later, a 35 y/o female clerk also presents complaining of myalgias, shaking chills, and vomiting. She is pale, and has a temperature of 102.4°F. Her physical exam is non-focal, she improves with antipyretics and the patient is sent home with viral syndrome instructions.

7. Biologic Agent Case The next day several more patients present with fever, chills and myalgias.

8. Biologic Agent Case • The 40 yo policeman returns 3 days later because he is feeling much worse and is short of breath. • This is the chest x-ray that was obtained

9. Biologic Agent Case • A mother brings in her adolescent son for a strange black scab/rash that started out as a small papule but formed a black painless eschar over the past 5 days.

10. Biologic Agent Case • Another family brings in their adolescent daughter for evaluation of a “bad infection” • Surrounding facial edema is uncomfortable/painful • The developing eschar is relatively painless

11. Biologic Agent Case • The ED calls your office informing you of the admission of the 35 yo female for fever, mental status changes, meningismus, pneumonia, hypoxia, respiratory distress and shock. • After LP, the gram-stain was described as gram positive rods with spores.

12. What is the Agent?

13. Anthrax (Bacillus anthracis) • Where is it found naturally? • History as a biological weapon • How does it cause disease? • What types of disease does it cause (clinical effects)? • Treatment

14. Naturally Occurring Anthrax • Caused by a gram-positive spore forming rod • Spore if very hardy can survive for decades in the soil • Important veterinary disease as herbivores may be prone to the disease if they feed in ‘anthrax zones’

15. Naturally Occurring Anthrax • Endemic cases are usually present as cutaneous disease(95%; <1-20% mortality) • Contracted by contact of abraded skin with products of infected cattle, sheep and goats • Products include hides, hair, wool, bone and meat.

16. Naturally Occurring Anthrax • Inhalational anthrax (wool sorter’s disease) from inhalation of spores from textile and slaughterhouse workers (<5% cases; 45-89% mortality) • Gastrointestinal Anthrax is very rare and occurs from consuming infected meat (<5%; >50% mortality)

17. Weaponized Anthrax • WHO estimates that 50 Kg dispersed along a 2 Km line upwind of a city of 500,000 could cause 125,000 infections and 95,000 deaths However • May be difficult to weaponize into small enough particles • ID50 of 8,000 to 10,000 spores

18. Weaponized Anthrax History Sverdlovsk, Russia, 1979 • Accidental release from biological weapons facility due to a faulty filter • Plume swept over city by the wind • ≥77 cases, 66 deaths • Last person became ill 43 days after initial release

19. Weaponized Anthrax History • October 2001 letter associated Anthrax outbreak • 22 cases • 11 Inhalational (5 deaths) • 11 Cutaneous (No deaths) • Very different distribution compared to naturally occurring disease

20. Anthrax Disease Process • Anthrax has at least three proteins which play a role in virulence • A-B model of toxicity • Edema factor (EF), Lethal factor (LF) and Protective antigen (PA) • EF and LF need PA to get into the cell to cause damage

21. Anthrax Disease Process • EF + PA creates edema toxin • LF + PA creates lethal toxin • The toxins cause lymphatic necrosis which leads to the release of Bacillus anthracis

22. Anthrax Disease Process

23. Cutaneous Anthrax • Progression of painless lesions Papule/macule – pruritic Vesicle/bulla – clear or serosanguinous Ulcer – nonpitting, gelatinous edema Eschar – black, depressed, rarely scars, 24-48 hrs days

24. Cutaneous Anthrax

25. Cutaneous Anthrax

26. Inhalational Anthrax Clinical Features • Initially starts with a non-specific flu-like illness and then progresses to: • Respiratory Distress • Shock • May see a widened mediastinum on x-ray

27. Anthrax – Hemorrhagic Meningitis

28. Gastrointestinal Anthrax • Nausea, anorexia, vomiting, fever • Progresses to severe abdominal pain and bloody emesis and diarrhea • Ascites may develop on day 2 - 4 • Death 2 to 5 days after onset of symptoms • Very difficult to diagnose

29. Treatment Cutaneous Anthrax • without systemic signs, extensive edema or lesions located on head and neck. • Initial recommended treatment: • Doxycycline or Ciprofloxacin PO for 60 days

30. Treatment Cutaneous Anthrax • with systemic signs, extensive edema or lesions on the head and neck. • Initial recommended treatment: • Doxycycline or Ciprofloxacin IV • May switch to PO when clinically appropriate

31. Treatment Inhalational, GI, Sepsis • Initial recommended treatment: • Doxycycline or Ciprofloxacin IV • May switch to PO when clinically appropriate

32. Questions?

33. Question #1 The antibiotic of choice among the following for treating an anthrax infection is: • Cefuroxime • Doxycylcine • Penicillin • Pentamidine • Trimethoprim-sulfamethoxazole

34. Question #2 The most common naturally occurring form of anthrax is: • Cutaneous • Gastrointestinal • Inhalational • Ocular • Mediastinal

35. Question #3 Which of the following is an isolated protein necessary for the virulence of anthrax? • Edema toxin • Lethal toxin • Lymphatic factor • Necrosis factor • Protective antigen

36. Question #4 The order of development of the classic cutaneous anthrax lesion is: • Bullae, vesicle, ulcer, eschar • Papule, vesicle, ulcer, eschar • Vesicle, bullae, eschar, ulcer • Ulcer, vesicle, bullae, eschar

37. Question #5 After low-level germination at the site of entry to the body, anthrax may be taken up by: • Basophils • Eosinophils • Lymphocytes • Macrophages • Neutrophils

38. This completes the current presentation.