Makindo Medical Notes

⚠️ Early diagnosis of Anthrax and the prompt initiation of combination antimicrobial therapy are critical for survival. 💨 Inhalational anthrax, in particular, carries a high mortality if untreated and requires immediate critical care involvement.

📖 About

• 🐏 Anthrax (from Greek “coal”) refers to the black eschar in cutaneous disease.
• Caused by Bacillus anthracis, a spore-forming zoonotic bacterium that infects herbivores.
• Transmission occurs via contaminated hides, wool, or meat; also relevant in bioterrorism.

🔬 Characteristics

• Gram-positive, aerobic, spore-forming bacillus.
• 🌱 Spores can persist in soil/environment for decades.
• 🛡️ Polypeptide capsule (D-glutamic acid) is antiphagocytic.
• Infection routes: skin, inhalation, ingestion → systemic disease possible.

Eschars

🌍 Source

• Contaminated soil, carcasses, and animal products (hides, wool, meat).
• Endemic in:
  • 🌎 Central & South America
  • 🌍 Sub-Saharan Africa
  • 🌏 Asia & Eastern Europe
  • 🌴 The Caribbean
• 🔺 Bioterrorism example: US anthrax letters (2001).

🧪 Virulence

• 🛡️ Protective antigen (PA): enables toxin entry into host cells.
• ☠️ Lethal factor (LF): cleaves MAP kinase → apoptosis.
• 💧 Oedema factor (EF): ↑cAMP → fluid leak & immune dysregulation.
• Combined → necrosis, oedema, haemorrhage, immune evasion.

🧠 Pathophysiology

🤒 Clinical Forms

• 🖐️ Cutaneous Anthrax (~95% cases):
  • Entry via skin abrasions → painless ulcer + black eschar.
  • Can progress to lymphadenitis & systemic infection.
• 💨 Inhalational Anthrax (“wool sorters’ disease”):
  • Flu-like prodrome → rapid respiratory distress, cyanosis, shock.
  • Classic sign: widened mediastinum ± pleural effusion.
  • Mortality >50% untreated.
• 🍖 Gastrointestinal Anthrax:
  • From undercooked infected meat.
  • Nausea, bloody diarrhoea, perforation, high mortality.
• 🩸 Systemic Anthrax:
  • Shock, renal failure, DIC, meningitis (often haemorrhagic & fatal).

🔍 Investigations

• 🔬 Microscopy: Gram stain, special staining (e.g., Ziehl-Neelsen variant).
• 🧪 McFadyen’s reaction: polychrome methylene blue → capsule seen.
• 🧬 PCR & Culture: confirmatory, though culture may be slow.
• 📷 CXR: widened mediastinum, pleural effusions in inhalational form.
• 🧪 Bloods & serology: capsular antigen detection.

💊 Management (Infectious Diseases input essential)

• 🛡️ Prevention: vaccination in military/veterinary at-risk groups.
• 🚑 Supportive: ABC resuscitation, oxygen, IV fluids, ITU if severe.
• 💊 Antibiotics:
  • First-line: Ciprofloxacin, Levofloxacin, or Doxycycline.
  • Combination therapy (e.g., add aminoglycoside/rifampin).
  • If susceptible: Benzyl Penicillin may be used (esp. cutaneous).
  • ❌ Avoid cephalosporins (resistance).
• 🧴 Antitoxins: Raxibacumab (monoclonal antibody) or anthrax immunoglobulin for systemic disease.
• 💉 Prophylaxis: 60 days of ciprofloxacin or doxycycline after spore exposure.
• ➕ Corticosteroids (e.g., dexamethasone) for meningitis or airway oedema.

💊 Anthrax – Typical Antimicrobial Dosing (verify with BNF/datasheet)

📚 References

• CDC Anthrax Guidelines
• WHO: Anthrax Overview
• MedlinePlus: Anthrax