Infective Endocarditis (IE)
HACEK Endocarditis

HACEK Endocarditis


  • Fastidious gram-negative bacilli, grow slowly in standard blood culture media and may require prolonged incubation (only a small fraction will demonstrate growth)
  • Haemophilus species, Aggregatibacter species, Cardiobacterium hominis, Eikenella corrodens, Kingella species
  • Bacteremia caused by HACEK organisms in absence of obvious focal infection is highly suggestive of IE, even without typical physical findings of IE
  • Without susceptibilities, consider them ampicillin and penicillin resistant

Recommended Treatment

Preferred, alternatively may use cefotaxime or another 3rd or 4th generation cephalosporin


For patients unable to tolerate cephalosporin therapy; levofloxacin or moxifloxacin may be substituted; fluoroquinolones generally are not recommended for patients <18 yrs old

Duration of Therapy

Native valve: 4 weeks

Prosthetic valve: 6 weeks