𧨠Bioterrorism: Six organisms are classified as highest-priority ("Category A" by CDC/WHO).
They are highly lethal, easily disseminated, cause public panic, and strain healthcare systems:
Anthrax, Smallpox, Plague, Tularemia, Botulism, and Viral Haemorrhagic Fevers.
In the UK, preparedness falls under the Civil Contingencies Act and NHS England emergency frameworks.
1οΈβ£ Anthrax (Bacillus anthracis, spore-forming)
- π Diagnosis: Inhalational form β widened mediastinum (CXR), haemorrhagic mediastinitis.
Cutaneous β black eschar π©Ή.
GI β severe sepsis after contaminated meat.
- π― Weaponization: Spores highly stable π±, aerosolisable, 45β85% mortality untreated inhalational cases.
- π Treatment: Ciprofloxacin 400 mg TDS (first-line). Add carbapenem (meropenem 2 g TDS / imipenem 1 g QDS) + protein synthesis inhibitor (linezolid, clindamycin, rifampicin, or chloramphenicol).
2οΈβ£ Smallpox (Variola virus)
- π Diagnosis: Synchronous vesicularβpustular rash π, fever & rigors precede rash. Centrifugal distribution (face & extremities first).
- π― Weaponization: Population is immunologically naΓ―ve (vaccination stopped 1970s). Virions stable in dried scabs π§«. Mortality ~30% historically.
- π Treatment: Supportive (isolation, fluids, antibiotics for secondary infection). Antivirals: cidofovir, tecovirimat (investigational in UK).
3οΈβ£ Plague (Yersinia pestis)
- π Diagnosis: Pneumonic form β cough, haemoptysis, rapid decline π. Bubonic β painful buboes. Septicaemic β DIC, purpura fulminans.
- π― Weaponization: Easily spread by droplets π·, associated with historic "Black Death". Mortality untreated >90% (pneumonic).
- π Treatment: Gentamicin 5 mg/kg OD OR ciprofloxacin 400 mg BD OR doxycycline 200 mg loading then 100 mg BD.
4οΈβ£ Tularemia (Francisella tularensis)
- π Diagnosis: Plague-like illness with ulceroglandular lesions π¦ . Pneumonic form is most lethal. Extremely infectious (10 organisms inhaled can cause disease).
- π― Weaponization: Very low infectious dose, stable in environment, incapacitating.
- π Treatment: Same as plague (gentamicin, ciprofloxacin, doxycycline).
5οΈβ£ Botulism (Clostridium botulinum toxin)
- π Diagnosis: Descending symmetrical flaccid paralysis π§βπ¦½. Diplopia, dysarthria, dysphagia, respiratory muscle weakness. Sensation normal, no fever.
- π― Weaponization: Most potent toxin β οΈ. Potential contamination of food/water. Massive ICU/ventilation demand.
- π Treatment: Ventilatory support critical. Botulinum antitoxin halts progression but does not reverse paralysis.
6οΈβ£ Viral Haemorrhagic Fevers (Ebola, Lassa, Marburg, CCHF)
- π Diagnosis: Fever & myalgia β shock, haemorrhage, multi-organ failure π©Έ. Petechiae & mucosal bleeding common. Case fatality 25β90%.
- π― Weaponization: High fear factor, person-to-person spread possible, limited countermeasures.
- π Treatment: Supportive (fluids, organ support, strict isolation π§βπ¬). Ribavirin helps in Lassa, some arenaviruses & CCHF (loading 30 mg/kg β 16 mg/kg QDS Γ4d β 8 mg/kg TDS Γ6d, experimental).
π‘ Clinical Pearls
- π¬ Anthrax & tularemia β not contagious (mass exposure concern).
- π§ Smallpox & plague β contagious β isolation & ring vaccination vital.
- π€ Botulism = pure toxin, no fever or inflammation.
- π§ͺ VHFs need BSL-4 labs; UK has designated HCID (High Consequence Infectious Disease) centres.