HAEMOPHILUS
THE BLOOD-LOVING BACILLI
HAEMOPHILUS
• Tiny gram negative, pleomorphic rods
• Nonmotile
• Fastidious
• Sensitive to drying, temperature extremes and disinfectants
• Some species are normal colonists of URT or vagina
• Factor X, hemin
• Factor V ( NAD or NADP)
• Chocolate agar
Satellitism
• Aerobic gram-negative bacteria
• Polysaccharide capsule
• Six different serotypes (a-f) of
polysaccharide capsule
• 95% of invasive disease caused by
type b (Hib)
Haemophilus Influenzae
Haemophilus influenza
• 1892 Pfeiffer, it was isolated from patients with “flu”
• Real agent ‘influenza virus’( 40 years later)• Acute bacterial meningitis• Sporadic outbreaks in daycare and family
settings.• Transmission by close contact and nose and
throat discharges.
Haemophilus Influenzae Type bSevere Bacterial Infection, primarily in infants
Before introduction of vaccines:• Leading cause of bacterial meningitis and other
invasive bacterial disease - children <5 years.• Two-thirds of cases were among children <18
months.• Approximately one in 200 children developed
invasive Hib disease before the age of 5 years.• Since 1988 when Hib conjugate vaccines were
introduced, the incidence of invasive Hib disease in infants and young children has declined by 99%.
Clinical Presentation
Meningitis:Fever, headache, nausea, vomiting, stiff neck, sensitivity to light (photophobia), coma; and in infants, poor feeding and a bulging fontanelle.
Epiglottis:Sudden onset of sore throat, fever, and shortness of breath, progressing rapidly to difficulty swallowing and pooling and drooling of saliva due to the obstructed airway.
Cellulitis
6%
Arthritis
8% Bacteremia
2%
M eningitis
50%
Epiglottitis
17%
Pneumonia
15%
Osteomyelitis
2%
Haemophilus influenzae type bClinical Manifestations*
*prevaccination era
Case Definition
Clinical case definition
Invasive disease caused by H. influenzae can produce any of several clinical syndromes, including meningitis, bacteremia, epiglottitis, or pneumonia.
Laboratory criteria for diagnosis
Isolation of H. influenzae from a normally sterile site (e.g., blood or cerebrospinal fluid [CSF] or, less commonly, joint, pleural, or pericardial fluid).
• Treatment:
- Combination of chloramphenicol and ampicillin
- Prophylaxis:
rifampin
Hib vaccine, beginning at age 2 months with three follow-up boosters.
available in combination with DTaP as TriHiBit
H.aegyptius
• Acute communicable conjunctivitis (pinkeye)
• Subconjunctivalhemorrhage
• Primarily in children• Spread with fingers• Gnats and flies• Antibiotic eydrops
H.ducreyi
• Chancroid( soft chancre) • STDs prevalent in tropics subtropics • Afflicted mostly males• Transmitted by direct contact with infected
lesions,• Incubation of 2-14 days• Lesions develop in genital or perianal area• Inflammatory macule that evolve into a painful
necrotic ulcer similar to LGV and Syphilis
H.Parainfluenza & H.aphrophilus
• Normal flora of oral and nasopharyngeal
• Involved in infective endocarditis
routine dental procedures
periodontal disease
some other oral injury
:یکتعداد خصوصیات تفریقی بین ھیموفیلوس ھا Species نیازمند Hemolysis
XVH. influenza ( H. aegypticus) + + -H. parainfluenza - + -H. ducreyi + - -H. hemolyticus + + +H. para hemolyticus - + +H. aphrophilus - - -