Anthrax

Question 1

• Organism Type: Aerobic, gram-positive, spore-forming, nonmotile, rod-shaped bacterium.
• Scientific name: Bacillus anthracis.

Answer 1

Anthrax

Question 2

Predisposing Factors for anthrax

Answer 2

• Working with any unvaccinated animal that is a
  common anthrax reservoir.
• More common in ranchers, leather workers, veterinarians, wildlife researchers.

Question 3

Transmission of anthrax

Answer 3

• Handling B. anthracis–infected animals, carcasses,
  meat, hides, or wool.
• Products derived from infected animals are also documented sources of human infection

Question 4

Incubation of anthrax

Answer 4

1–7 days; upwards of 12 days in rare cases.

Question 5

Zoonotic disease primarily affecting ruminant herbivores such as cattle, sheep, goats, antelope, and deer that become infected by ingesting contaminated vegetation, water, or soil

Answer 5

Anthrax

Question 6

How are anthrax spores introduced to skin

Answer 6

• Spores introduced through the skin can result in cutaneous anthrax; abrasion of the skin increases susceptibility.
• Anthrax in humans generally is not considered contagious; person-to-person transmission of cutaneous anthrax has been reported only rarely.

Question 7

Anthrax has 4 main clinical presentations

Answer 7

• Cutaneous
• Ingestion,
• injection
• Inhalation.

Question 8

Most common form of anthrax in humans

Answer 8

Cutaneous anthrax (95-99%)

Question 9

• B. anthracis spores introduced under skin start to multiply and spread.
• Organism makes exotoxin that causes marked edema and causes tissue necrosis.
• Eschar with extensive surrounding edema is hallmark.
• Can be transmitted from the discharge from skin lesions.

Answer 9

Cutaneous anthrax

Question 10

Presentation:
- Small, painless, pruritic papules emerge anywhere from 1 – 12 days after exposure.
- Papules enlarge rapidly to vesicles or bulla (blisters).
- Vesicle or bulla start to erode and leave painless black necrotic ulcer.

Answer 10

Cutaneous anthrax

Question 11

Dx of cutaneous anthrax

Answer 11

• Vesicular fluid and ulcers should be swabbed for gram stain and culture and PCR.
• Eschar edge should be lifted and swabbed.

Question 12

Treatment of Cutaneous Anthrax

Answer 12

• Suspected case of anthrax should be referred to an infectious disease specialist
• Ciprofloxacin 500mg PO BID x 7-10 days.
• Levofloxacin 750mg PO QD x 7-10 days.
• Doxycycline 100mg PO BID x 7-10 days.

Question 13

Prevention of Cutaneous Anthrax

Answer 13

• Vaccine should be administered to high-risk personnel, including military personnel who deploy to endemic areas.
• Precautions should be taken when handling animals or animal products, especially the hides.

Question 14

Disposition of Anthrax

Answer 14

• Any patient suspected of an anthrax infection requires an immediate referral and/or medevac to an appropriate treatment facility.
• If untreated, cutaneous anthrax may result in sepsis or meningitis.