H.INFLUENZAE

H.INFLUENZAE

Q1: What is H.influenzae?

• H.influenzae is a gram-negative coccobacillus
• It is a commensal that can become pathogenic

Q2: Diseases caused by H.influenzae

• Meningitis
• Pneumonia
• Epiglottitis
• Otitis media
• Septicaemia
• Sepsis
• Bacteremia

Q3: Describe the laboratory diagnosis of H.influenzae

• Culture: Blood, CSF, or respiratory secretions
• Identification: colony characteristics, Gram stain
• Biochemical tests: catalase positive, oxidase positive
• Serological tests: Widal test, Weil Felix test
• Molecular tests: PCR, DNA hybridization

Q4: Pathogenesis of H.influenzae → Invades epithelial cells → Causes necrosis and inflammation → Produces toxins and virulence factors → Invades blood vessels → Causes sepsis and meningitis

Q5: Morphology of H.influenzae

• Gram-negative coccobacillus
• Size: 0.5-1.0 um x 0.5-2.0 um
• Shape: pleomorphic, coccobacillary

Q6: Clinical features of H.influenzae

• Fever
• Headache
• Stiff neck
• Cough
• Sputum production
• Chest pain
• Septicaemia

Q7: Complications of H.influenzae

• Meningitis
• Pneumonia
• Epiglottitis
• Otitis media
• Septicaemia
• Sepsis
• Bacteremia

Q8: Management of H.influenzae

• Antibiotics: ampicillin, cephalosporins
• Supportive care: hydration, oxygen therapy
• Surgery: drainage of abscesses
• Vaccination: Hib vaccine

Q9: Memory trick for pathogenesis

• "Ivy Invades, Causes Inflammation, Produces Toxins, Invades Blood, Causes Sepsis"

Q10: Word trick for remembering H.influenzae

• "H-influ (influence) enza (influenza) e (e) a (alpha) e"