bacterial infections of childhood

Question 0

diphtheria

Answer 0

-corynebacterium diphtheria: aerobic, pleomorphic, gram + rod
SX: fever, malaise, gray membrane in tonsils and posterior oropharynx. if try to remove –> bleeds
-spread via resp, oral droplets, enters pharynx and multiply in tonsils –> THICK GRAY LEATHERY MEMBRANES

• diphtheria toxin (MOST POTENT TOXIN, encoded by lysogenic b-bacteriophage) is absorbed systemically and acts on may tissues (has A(binds) and B(stops protein syn) subunit).
• **most susceptible:
• heart (fat droplets and focal necrosis), kidneys, nerves (PERIPHERAL NERVE DEMYELINATION)

-may caouse cutaneous diphtheria (pustules/ulcers)

Question 1

4 bacterial infections of childhood

Answer 1

1. diptheria
2. pertussus
3. haemophilus influenzae
4. Neisseria meningitides aka meningococcus

Question 2

pertussis

Answer 2

-Bordetella pertussis: whooping cough (inspiratory, high-pitched, whoop).
-highly contagious via resp aerosols, primarily in kids inc pna risk –> death common. toxin: pronounced lymphocytosis thats assoc with whooping cough. causes extensive trachobronchitis
3stages:
1. catarrhal stage: resembles common viral upper resp illness: low grade fever, runnynose, conjunctivitis, cough
2. paroxysmal stage: 1 week into illness, paroxysmal cough (5-15coughs) followed by insp whoop. WBC >40,000, lasts 2-3wks
3. convalescent phase –> several weeks.

Question 3

haemophilus influenzae - OI

Answer 3

leading cause of BACTERIAL MENINGITIS in kids <2yr/ UNVACCINATED PTS WORLDWIDE, serious in infants/toddlers bc dec immunity

• spread by resp droplets.
• normal flora in 20-50% of adults
  1. meningitis: predominantly acute infm leptomeningeal infiltrate
  2. EPIGLOTTITIS: obst aw
  3. facial cellulitis: fever, profound malaise, raised hot, red blue discolored area of face (cheek, eye area)
  4. septic arthritis: 2ary to seeding in joints; fever, heat, erythema, pain, swelling

SX: young kids, may follow upper resp infection or otitis media: bronchopna, lobar pna, fever, cough, purulent sputum, SOB

Question 4

Neisseria meningitidis aka MENINGOCOCCUS

Answer 4

• normal flora of few ppl, spread by resp droplets, most in closedquarters. systemic effects are due to endotoxin of outer membrane lipopolysaccharide (inc TNF, complement, coagulation –> DIC, fibrinolysis, shock)
• colonize in upper resp tract, we make ab’s. if cannot get rid of it –> spread to blood cause MENINGOCOCCAL DZ (CNS) or disseminate in body

MENINGOCOCCAL SEPTICEMIA: diffuse damage to small bv endothelium –> petechiae, purpura in skin and viscera. some cases lead to VASCULITIS AND THROMBOSIS, hemorrhagic necrosis of ADRENALS (waterhouse friderichsen sd - shock, DIC, adrenals)

-SX: rapid fever, stiff neck, headache. in meningococcol sepsis: fever, shock, mucocutaneous hemorrhages appear abruptly:
TX: Ab and pressors
if survive: vasculitis –> gangrene, polyarthritis, pericarditis