Bj

1. HAEMOPHILUS
Saroj Kumar Thakur
B.Sc.MLT, M.Sc. Medical Microbiology
(Medical Microbiologist)
Madesh Institute of Health Sciences
(Provincial Hospital)

2. MORPHOLOGY
 Gram negative bacilli
 Slender & short coccobacilli
 1-2um*0.3-0.5um in size
 Non-sporing, capsulated
 Nonmotile
 Pleomorphic
 Filamentous form are seen in
CSF

3. CULTURAL CHARACTERISTICS
 Growth is better in aerobic condition
 Need 5-10%CO2
 fastidious
 Optimum temperature 20-42°c
 Requires factor X & V-bacterial vitamins present in blood
for growth

4. Culture media
 Sheep blood agar: pin point colonies
 Chocolate agar: X & V factor released from RBCs lysis,
good for isolation
 Leventhal’s Agar: Transparent medium containing extract
of blood
 Filde’s agar: composed of Nutrient agar & digest of blood

5. PATHOGENESIS
H. Influlenzae is an exclusively human pathogen
 Invasive
 Meningitis
 Common in children b/w two month & three years of age
 Fatality rate is up to 90%
 Bacilli reach meninges from nasopharynx through blood
stream

6.  Laryngoepiglottis or croup
 Second common disease
 Acute inflammation of epiglottis with obstructive
laryngitis, which may need tracheostomy
 Untreated cases may be fetal in hours
 Usually associated with bacteraemia

7.  Pneumonia
 Common in infant
 In adult & children, it causes lobar pneumnia
 Bronchopneumonia may occur as secondary infection
with non capsulated strains

8.  Suppurative infection
 Arthiritis, endocarditis, pericarditis may develop due to
haematogenous dissemination
 Buccal periorbital cellulitis

9.  Noninvasive
 Otitis media
 Sinusitis
 Acute exacerbation of chronic bronchitis

10. LABORATORY DIAGNOSIS
 Specimens: CSF, Blood, Sputum
 Processing of Specimen
 Microscopic:
 Gram stain
 Wet preparation- csf shows of plenty of pus cells &
bacteria
 Immunofluorescence test- direct detection of bacilli in
smear by treating with antibody conjugated with
fluorescence tag
 Quellung reaction- direct demonstration of capsule after
mixing with antisera

11.  Culture
 AST
 Serotyping: with specific antisera
 Treatment
sulphonamides, chloramphenicol, trimethoprim,
tetracucline, ciprofloxacin, amoxyclav

12. PROPHYLAXIS
 A purified type b capsular polysaccharide vaccine is used
in children of 18-24 months. Vaccine is administered in
two doses at an interval of two months.
 Hib PRP (Haemophilus influenzae type B-polyribosyl
ribitol phosphate) vaccine in which type b capsular
polysaccharide is covantely coupled to proteins such as
diptheria toxoid, tetanus toxoid & N. meningitidis. such
Hib PRP are available for use in young children.

13.  Rifampicin is given for four days to prevent infection in
contact & also to eradicate carrier state