View source for Haemophilus influenzae

==Background==
===Microbiology===
* Species of [[Stain::Gram-negative]] [[Shape::bacillus]] within the genus [[Genus::Haemophilus]]
* Deficient heme biosynthetic pathway leading to X-factor-dependent growth on media
* Fastidious growth with standard media
* May be encapsulated; non-encapsulated strains are referred to as "nontypeable"
* The group includes ''Haemophilus influenzae'', [[Haemophilus aegyptius]], and [[Haemophilus haemolyticus]]

{{DISPLAYTITLE:''Haemophilus influenzae''}}
{| class="wikitable"
! rowspan="2" |Test
! colspan="8" |Biotype
|-
!I
!II
!III
!IV
!V
!VI
!VII
!VIII
|-
|Indole
| +
| +
|–
|–
| +
|–
| +
| +
|-
|Urease
| +
| +
| +
| +
|–
|–
|–
|–
|-
|ODC
| +
|–
|–
| +
| +
| +
|–
|–
|}

== Clinical Manifestations ==

* [[Community-acquired pneumonia]], particularly in children, [[meningitis]], [[bacteremia]], mainly type b strains
* [[Community-acquired pneumonia]], [[acute otitis media]], [[acute sinusitis]], [[acute exacerbation of COPD]], mainly untypeable strains

== Management ==

* For beta-lactamase-negative strains, [[ampicillin]] is recommended
* For beta-lactamase-positive strains, [[ceftriaxone]] or [[cefepime]]
* Alternatives include [[chloramphenicol]], [[ertapenem]], [[meropenem]]
* Possibly also a [[Fluoroquinolones|fluoroquinolone]], [[azithromycin]], [[clarithromycin]], [[doxycycline]], [[amoxicillin-clavulanic acid]]
* Duration depends on syndrome being treated:
** Uncomplicated [[Bacterial meningitis|meningitis]]: 10 days
** [[Community-acquired pneumonia|Pneumonia]]: at least 5 days, with clinical improvement
** [[Septic arthritis]]: 10 to 14 days
** [[Pericarditis]]: 3 to 6 weeks
** [[Empyema]]: 3 to 6 weeks
** [[Osteomyelitis]]: 3 to 6 weeks

== Further Reading ==

* Antimicrobial Resistance in ''Haemophilus influenzae''. ''Clin Microbiol Rev''. 2007. doi: [https://doi.org/10.1128/CMR.00040-06 10.1128/CMR.00040-06]

[[Category:Gram-negative bacilli]]