ANTHRAXANTHRAX
D. Goldberg, MD
Ped ID Service
WRAMC
AnthraxAnthrax
• Etiology-Bacillus anthracis toxin producing gram positive encapsulated spore forming non motile rod
AnthraxAnthrax
AnthraxAnthrax
• zoonotic disease-spores found on skin/hides carcasses of goats, cattle, horses, buffalo, sheep. Spread thru contaminated meat, feed, soil
• agricultural disease-spores found in soil and remain viable for up to 40 years
• incubation period is 1-7 (2-5) days
Anthrax-Anthrax-
• Inhalation-18 cases/US 1900-1978
• Cutaneous-2000 cases/yr
244 cases/US 1944-1994
• Gastrointestinal-occasional outbreaks
AnthraxAnthrax
• Sverdlovsk (1979)-79 cases /68 deaths due to accidental aerosolized release
• WHO (1970)-50 kg aersolized over rban population would lead to 100,000 deaths
• US Congress (1993)-100 kg lead to 130,000-3 million deaths
AnthraxAnthrax
• Cinical- Three forms:
Cutaneous
Gastrointestinal-
oropharyngeal/abdominal
Inhalational
Anthrax-CutaneousAnthrax-Cutaneous
• 95% of all American cases
• Requires a break in the skin
• Initial manifestation is itching--> papule--> vesicle--> depressed painless black eschar
Anthrax-CutaneousAnthrax-Cutaneous
• Eschar surrounded by secondary vesicles (1-3mm) and erythema
• Untreated case fatality 5-20% due to spread into lymph/bloodstream
• No data to suggest prolonged latency (>14 days)
Anthrax-CutaneousAnthrax-Cutaneous
Anthrax-GastrointestinalAnthrax-Gastrointestinal
• Due to ingestion of infected undercooked meat
• Presents with nausea, fever, bloody diarrhea,
• Often proceeds to toxemia, shock and death (fatality rate -50%)
Inhalation Anthrax-PathogenesisInhalation Anthrax-Pathogenesis
• Spore particles- 1-5 m
• Spores transported to mediastinal lymph nodes (germination may be delayed up to 60 days)
• Spores release toxins-
hemorrhage, edema, necrosis
Anthrax-InhalationAnthrax-Inhalation
• Inhalation of 8000-50,000 spores
• Initial sx are of mild URI, malaise, fatigue
• Initial sx followed by short period of improvement (hrs-2 days)
Anthrax-InhalationAnthrax-Inhalation
• Day 3-5 beginning of increasing resp distress of fever, tachypnea, rales, cyanosis
• CXR-mediastinal widening +/- effussions are seen in late stage in 55% cases
• Pneumonia generally does not occur
Anthrax-InhalationAnthrax-Inhalation
Anthrax-InhalationAnthrax-Inhalation
• Associated with hemmorhagic menningitis in 50% cases
• Case fatality rate is 100% untreated. Treatment begun “late” is ineffective
Anthrax-DiagnosisAnthrax-Diagnosis
• Gram stain of nasal swab/ discharge/lesion
• Culture
• ELISA for toxin
• Fluorescent Ab
• PCR
Inhalation Anthrax-TherapyInhalation Anthrax-Therapy
• Treatment-
Ciprofloxacin (400mg IV q12) switch to Pen or Doxy if sensitive for 60 days
• Prophylaxis-
Ciprofloxacin (500mg po q12) switch to Pen or Doxy if sensitive for 28-60days
Inhalation Anthrax-TherapyInhalation Anthrax-Therapy
Pediatric Guidelines
• Initial therapy-Cipro 10-15 mg/kg/dose q12 then switch pending sensitivity
• Prophylaxis-same
Inhalation Anthrax-Inhalation Anthrax-Alternative TherapiesAlternative Therapies
• Doxycycline 2.5 mg/kg (max=100) q 12 Doxycycline 2.5 mg/kg (max=100) q 12 when Cipro is unavailable/advisablewhen Cipro is unavailable/advisable
• Amoxicillin Amoxicillin 12-15 mg/kg q8 <20 kg 12-15 mg/kg q8 <20 kg
500 mg q8 >20 kg500 mg q8 >20 kg
after sensitivities are knownafter sensitivities are known
References:References:
• Anthrax as a Biological Weapon:
Inglesby, Henderson, et al; JAMA 281,18 1735-46 (May 1999)
• Chemical-Biological Terrorism and It's Impact on Children: Pediatrics 105,3 662-70 (March 2000)
• Bluebook-USAMRIID web site-