12. Lung infection Flashcards
Name 4 pathogens associated with community acquired pneumonia
Influenza A or B
RSV
Human rhinovirus
S pneumoniae
Name 4 pathogens associated with hospital acquired pneumonia
Staphylococcus aureus
Pseudomonas aeruginosa
Klebsiella species
E. Coli
5 types of risk factor for pneumonia
Lifestyle/ demographics: Age <2 or >65, smokers, alcoholics
Social factors: Poverty, contact with kids <15
Medications: Immunosuppressants, PPIs
Medical history: COPD, Heart/liver disease
Specific: Geographical location
Describe pneumonia
Disease of lung interstitium Pleuritic chest pain Usually febrile Often hypoxic, confused New X ray changes Productive cough: puss, dead neutrophils Rusty sputum seen in strep pneumoniae
Describe acute bronchitis
Disease of the airways
Cough
Tracheal pain, not pleuritic
No new X ray changes
What supportive therapy is required to treat pneumonia alongside antibiotics?
Oxygen (for hypoxia)
Fluids (for dehydration)
Analgesia (for pain)
How does pneumonia arise?
Viral infection damages epithelium
Damaged epithelium less able to clear pathogens
Promotes bacterial growth
If immune system is performing intense viral response, may not be able to simultaneously perform intense bacterial response
Viral infection can “distract” immune system
3 causes of severe flu
Highly pathogenic strains (zoonotic) Absence of prior immunity e.g. B cell deficiency Predisposing illness/conditions e.g. Elderly, COPD
Describe influenza
No re-infection by same strain
Constant evolution of genome
Imperfect vaccines: Annual vaccination required
Describe RSV
Recurrent re-infection with similar strains Genome is relatively stable No vaccine: Poor immunogenicity Vaccine-enhanced disease
What is the term given for congenital disease causing malfunctioning cilia? How does this disease affect the ultrastructure of the cilium?
Primary ciliary dyskinesia: caused by a dynein arm defect
Give 2 examples of acquired defects of the mucociliary system.
Smoking
Viral infections
Describe Bronchiectasis
Chronically dilated airways
Usually due to persistent infection
Harder to remove mucous, more infections occur, cycles continue
Describe Primary ciliary dyskinesia
Problem arises of itself
Affected dynein arms
Cant remove mucous
Bacteria stuck, multiply, cause infection
Name an innate host defence mechanism in the respiratory tract
IgA
