Haemophilus Influenzae

Question 1

type

Answer 1

Coccobacillus
Pleomorphic
Gram negative
Catalase positive
Coagulase
negative
Facultative
anaerobe

Question 2

Transmission
& season

Answer 2

Normal URT
floras

Question 3

Clinical Features

Answer 3

Thumb sign -Enlarged epiglottis
Fever, sore throat,
Dys/odynophagia,
restlessness, drooling,
hoarseness, muffled voice
- “Hot potato voice”
- Tripod position:
trunk leaning forward,
neck hyperextended,
chin thrust forward
- Aryepiglottic folds
thickening
- Stridor : obstruction
to large airways

Question 4

Presentation

Answer 4

Epiglottitis
Meninigitis
Otitis Media
Pneumonia
“HaEMOPhilus influenzae”
** DOES NOT CAUSE
INFLUENZA(that’s
orthomyxovirus)

Question 5

Pathogenesis

Answer 5

1. Pili
2. Non pilus adhesins
   E.g. P-2 outer membrane
   protein; attaches to sialic acid
   containing mucin
   oligosaccharides
3. Antiphagocytic
   capsule composed of
   Polyribitol
   Phosphate(PRP)
4. LPS: impairs ciliary
   function, endotoxin
5. IgA protease >30

Question 6

Diagnostic

Answer 6

• Serotyped
  according to
  capsule(A→ F)
  -Type B
  Invasive
  disease
• Non typable are
  unencapsulated
  Culture:
  Chocolate agar
  with X and V
  growth factors →
  heat. ONLY
  haemophilus sp
  that requires both
  X=hemin
  V factor:
  nicotinamide
  adenine
  dinucleotide(NA
  D)

Question 7

Prognosis &
Prevention

Answer 7

Vaccine
against Hib
only!!