27: Bioterrorism

Question 1

For anthrax:

1. Etiology
2. Toxins
3. Clinical
4. Diagnosis
5. Treatment

Answer 1

1. Bacillus anthracis; GPR, non-motile, non-hemolytic, rapid grower; non-contagious; spores viable for years
2. Edema factor, lethal factor, protective factor
3. Five types:
   
   • Cutaneous (5-20% fatality untreated)
     
     1. Direct inoculation of spores via abrasion
     2. Incubates 1-7 days
     3. Pruritic macule –> vesicle –> round ulcer –> black eschar (1-2 weeks)
     4. Surrounding edema/erythema but painless
     5. +/- painful regional lymphadenopathy
   • Inhalation
     
     1. Initial sx resemble flu
     2. Late sx include high fever, vomiting, respiratory distress, necrotizing hemorrhagic mediastinitis
     3. Fatal within 24-36 hours
     4. Meningeal involvement assumed
   • GI
   • Meningeal: in persons with SIRS
   • Injection: Europeans injecting drugs
4. Cutaneous: Vesicular fluid or border of skin lesion: gram stain, culture and sensitivity, PCR (best); skin biopsy: IHC; serology (ELISA IgG antibody); Inhalation: CXR: mediastinal adenopathy, pleural effusions; blood, pleural fluid or CSF: gram stain = large, GPRs, rough grayish colonies
5. 1 bactericidal (ciprofloxacin), meropenem, 1 protein synthesis inhibitor (linezolid) for 60 days; vaccine availale

Question 2

Why is smallpox a concern?

Answer 2

• Infectious via aerosol
• Rapid person-to-person transmission
• Worldwide immunity has waned
• Severe morbidity and mortality
• Clinical inexperience

Question 3

For smallpox:

1. Etiology
2. Epidemiology
3. Pathogenesis
4. Clinical
5. Diagnosis
6. Treatment

Answer 3

1. Variola major/minor; incubation 12-14d
2. Secondary spread to about 1-10 persons per case
3. Implant on oral/respiratory mucosa, migrate to regional lymph nodes, multiply in reticuloendothelial tissues
4. Abrupt onset of high fever, malaise, rigors, vomiting, backache, headache; 2-3d later, maculopapular rash (infective) on face, forearms or pharynx –> trunk and legs; lesions on palms/soles; macules –> vesicles –> pustules; deeply embedded in dermis
5. Swab vesicular/pustular fluid or remove scab for culture, EM, variola-specific PCR
6. No proven Rx; vaccine available

Question 4

Describe the differences between small pox and chicken pox:

1. Incubation period
2. Prodrome
3. Distribution
4. Depth of lesion

Answer 4

1. SP: 7-12d; CP: 14-21d
2. 2-4d; minimal
3. centrifugal, synchronous; centripetal, asynchronous
4. Dermal; subcutaneous

Question 5

What are contraindications for the Vaccinia (Dryvax) smallpox vaccine?

Answer 5

1. Immunodeficiency
2. Past/present eczema or atopic dermatitis diagnosis
3. Pregnancy or planned pregnancy
4. Other acute, chronic or exfoliative skin conditions while condition is active