haemophilus - freemicrobiology.free.fr/presentations/haemophilus.pdf · haemophilus influenzae type...

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 - - -