... blood from patients with suspected HACEK endocarditis may require up to 30 days to become positive, and the microbiology laboratory should be alerted when a HACEK organism is being considered ... causes invasive bone and joint infections, and H parainfluenzae has been isolated from other infections such as meningitis; brain, dental, and liver abscess; pneumonia; and septicemia Actinobacillus ... series, up to 3% of cases of infective endocarditis are attributable to HACEK organisms, most often A actinomycetemcomitans, Haemophilus species, and C hominis The clinical course of HACEK endocarditis...