diseases

• mucociliary escalator


   carries debris as far as the pharynx, where the fluid and mucus is then swallowed and the debris eliminated by the digestive system
• streptococcal pharyngitis


  (strep throat) (G. A. S.) local inflammation, fever, tonsillitis, enlarged lymph nodes, diagnosis by rapid antigen detection test
• streptococcus pyogenes 


  resistant to phagocytosis, streptokinases lyse clots, streptolysins are cytotoxic
• scarlet fever


  caused by G. A. S., erythrogenic toxin (exo), treated with penicillin & amoxicillin

  fine red rash, strawberry tongue, fever, red face, swollen glands on neck
• diphtheria


  caused by corynebacterium diphtheriae (g+ rod)

  forms tough white membrane in the throat, fibrin & dead tissue, blocks passage of air to the lungs
• cutaneous diphtheria


  forms skin ulcer

  exotoxin produced by lysogenized bacteria (circulates in the blood; damages heart & kidneys, difficulty breathing, paralysis, heart failure, & death)

  prevented by DTaP vaccine
• DTaP

  diphtheria, tetanus, & petussis
• epiglottitis


  can be caused by H. influenza type B, S. pyogenes, S. pneumonia, S. aureus

  epithelial & connective tissues on epiglottis, can be fatal if secretions make their way into the trachea
• otitis media


  infection of the middle ear

  caused by S. pneumoniae, nonencapsulated H. influenzae, M. catarrhalis, S. pyogenes, RSV

  treated with broad spectrum penicillin
• common cold

  rhinoviruses (30-50%), thrives at temps lower than body temp, coronaviruses (10-15%), enterovirus D68

  sneezing, nasal secretion, congestion, can lead to laryngitis & otitis media

  relief via cough surpressants & antihistamines: symptoms & lower risk of spread
• lower respiratory diseases

  bronchitis, bronchiolitis, pneumonia
• pertussis (whooping cough)


  caused by B. pertussis (g-), produces a capsule (allows attachment to ciliated cells in the trachea)

  destroys ciliated cells & shuts down ciliary escalator, tracheal cytotoxin of cell wall damages ciliated cells, pertussis toxin enters the bloodstream

  treated with erythromycin or other macrolides
• stages of pertussis


  stage 1: catarrhal stage (like the common cold)

  stage 2: paroxysmal stage (violent coughing, gasping for air)

  stage 3: convalescence stage (may last for months)
• tuberculosis


  caused by mycobacterium tuberculosis

  acids fast rod, obligate aerobe

  20-hr generation time

  lipids in cell wall make it resistant to drying & antimicrobials
• diagnosis of tuberculosis


  tuberculin skin test (inject & swell @ site)

  + = current or previous infection

  rapid blood test for IFN gamma & nucleic acid amplification test (NAAT)
• treatment of tuberculosis

  minimum of 6 mo. drug therapy due to slow growth & dormancy

  first-line drugs: isoniazid, rifampin, ethambutol, pyrazinamide

  second-line drugs: aminoglycosides, fluoroquinolones, streptomycin, para-aminoslicyclic acid (PAS)
• multi-drug resistant (MDR)


  resistant to first line drugs
• extensively drug resistant (XDR)


  resistant to second line drugs
• bacterial pneumonias


  typical & atypical

  lobar, bronchopneumonia, pleurisy
• lobar pneumonia


  infects lobes of lungs
• bronchopneumonia


  infects alveoli adjacent to the lungs
• pleural pneumonia


  pleural membranes inflamed
• pneumococcal pneumonia


  caused by S. pneumoniae (g+; 90 serotypes)

  infected alveoli, interferes with oxygen uptake

  diagnosis: optochin-inhibition test, bile solubility test, or presence of capsular antigen in urine

  treated with macrolides

  prevented with conjugated pneumococcal vaccine
• atypical pneumonia

  caused by H. influenzae (cephalosporins), Mycoplasma pneumoniae (tetracyclins), Chlamydophila pneumoniae (azothromycin)
• legionellosis


  caused by Legionellosis pneumophilia (aerobic, g-), transmitted by inhaling aerosols

  high fever & cough, treated with azithromycin & macrolides
• viral pneumonia


  complication of influenza, chicken pox, measles

  SARS-associated coronavirus: emerged in Asia 2003
• influenzavirus 


  contains 8 RNA and an outer lipid bilayer

  3,000-50,000 deaths in United States annually

  strands: avian, swine, mammalian

  swine serve as "mixing vessels" for new strains
• hemagglutinin (HA) spikes


  recognize & attach to host cells
• neuraminidase (NA) spikes


  helps virus separate from infected cell
• antigenic drift


  minor antigenic changes in HA & NA

  allow the virus to elude some host immunity
• antigenic shifts 


  changes great enough to evade most immunity

  lead to pandemics

  involve reassortment of RNA
• Pneumocystis pneumonia (PCP)


  protozoan or fungus

  asymptomatic on immunocompetent, pneumonia in immunocompromised

  indicator of AIDS

  lining of alveoli

  treated with trimethoprim-sulfamethoxazole
• Aspergillus fumigatus

  aspergillosis

  airborne conidia
• rhizomes & mucor


  mold spores
• coccidioides (valley fever)


  great immitator; dry soil
• blastomyces 


  blastomycosis

  wet soil
• bacterial meningitis


  normal microbiota in the throat moving into blood stream

  convulsions & coma

  death from shock & inflammation due to endotoxin & cell wall release

  viral meningitis is more mild
• haemophilus influenza meningitis


  gram - aerobic bacteria that lives in throat

  capsule antigen type B

  children 6 mo-4 yr old

  Hib vaccine
• Neisseria meningitides meningitis (meningococcal meningitis)


  aerobic, gram - diplococcus with capsule

  6 serotypes (vaccine protects A, C, Y, W, & B serogroups)

  40 % of people are healthy nasopharyngeal carriers

  mortality of 9-12% with antibiotic therapy; 80% without
• Streptococcus pneumoniae meningitis (pneumococcal meningitis)


  gram +, encapsulated diplococcus

  70% are healthy nasopharyngeal carriers

  children 1 mo-4 yr

  mortality 8% in children, 22% in elderly

  prevented by conjugated vaccine