Naegleria fowleri

Background

Microbiology

• One of the free-living amoebae

Epidemiology

• Found in warm fresh-water, including southern US

Clinical Manifestations

• Causes acute, aggressive primary amebic meningoencephalitis (PAM)
• Infection (PAM) is rapidly-progressing and almost uniformly fatal (141/145 cases in the US)

Management

• Unclear optimal management
• CDC recommendations are:
  • Amphotericin B 0.75 mg/kg IV q12h for three days followed by 1 mg/kg IV daily for 11 days, concurrent with
  • Amphotericin B 1.5 mg intrathecal once daily for 2 days followed by 1 mg intrathecal q2d for 8 days, concurrent with
  • Azithromycin 10 mg/kg (max 500 mg) PO/IV daily, plus fluconazole 10 mg/kg (max 600 mg) PO/IV daily, plus rifampin 10 mg/kg (max 600 mg) PO/IV daily, plus miltefosine 50 mg PO bid or tid for 28 days, concurrent with
  • dexamethasone 0.15 mg/kg IV q6h during the initial 4 days

• Note that the recommendation is specifically for conventional rather than liposomal amphotericin B
• Miltefosine dosing is bid if weight <45 kg and tid if weight ≥45 kg