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-