Haemophilus Influenzae

WHAT IS IT?

Haemophilus influenza is a gram negative cocobacillus bacterium.

Gram stain of HIB (source)
Gram stain of Haemophilus influenza (source)
CULTURE CHARACTERISTICS

Facultative anaerobic bacteria 

Requires factors V and X for culture.

MOLECULAR CHARACTERISTICS

Encapsulated organismcontains an antiphagocytic polysaccharid capsule (polyribosyl ribitol phosphate capsule). 

TRANSMISSION

Direct contact, respiratory droplets

CONDITIONS CAUSED

HEENT: meningitis, epiglottitis, purulent conjunctivitis, otitis externa

Respiratory: secondary pneumonia, pneumonia exacerbated COPD, bronchopneumonia

TREATMENT

Ampicillin, Amoxicillin and second generation cephalosporins (Cefaclor)

Rifampin can be used as prophylaxis for HIB

OTHER HY FACTS

Haemophilus influenza type B (HIB) is often the pathogen that is thought to cause pneumonia/meningitis

A vaccine for HIB exists that has dramatically reduced its incidence. Conjugate vaccine. 

Apslenic patients (such as those who have autosplenectomy in diseases such as sickle cell anemia) are predisposed to infection with encapsulated organisms such as HIB.

 

Page Updated: 06.18.2016