Pathology of Pneumonia: Part 2 - Causitive agents, infection routes and classification Flashcards
what are 2 examples of Gram +ve bacteria that cause pneumonia
Gram +ve bacteria:
- Streptococcus pneumoniae
- Staphylococcus aureus
what are 3 examples of Gram -ve bacteria that cause pneumonia?
- Haemophilus influenzae
- Klebsiella pneumoniae
- Legion pneumophila
what Gram +ve bacteria is the most common cause of community acquired pneumonia
streptococcus penumoniae
which Gram-type of bacteria is the most common cause of hospital acquired pneumonia?
Gram -ve
what are 4 examples of things other than bacteria that can cause pneumonia
- viruses
- mycoplasma (mycobacterium tuberculosis)
- fungi
- inorganic agents (dust/gases)
outline 3 routes that can cause pneumonia
- inhalation of pathogens/inorganic agents
- Dissemination
- Bacteraema phase
what is the main route of infection for pathogens/inorganic agents in pneumonia?
- inhalation of the pathogens/inorganic agents
how can pathogens/inorganic material be transmitted from person to person (Transmission)?
usually carried through water droplets that have either been coughed or sneezed out by an infected individual, and then breathed in by an uninfected individual
what is dissemination (in pneumonia but this is universal)?
- aspiration of oropharyngeal secretions and or gastric contents
can happen when someone vomits
what is bacteraema phase and when can it occur?
When severe bacterial infection somewhere else in the body or vice versa disseminates through systemic circulation to other places.
- can occur shortly after birth (from mother to child)
what 2 environmental factors can increase the chance of infection and disease and how?
Alcohol can reduce the cough reflex, leading to increased aspiration and increased chance of vomtting
cigarette smoke can lead to reduced mucociliary and macrophage action in respiratory tract, so inhalated pathogens can live longer.
classifiation of pneumonia
what are the 3 classifications of pneumonia and give brief description of each type
1. Anatomical classification
- how the infection is spread in the lungs
2. clinical setting in which the disease occurs
- what are the circumstances/factors surrounding the disease
3. microbiological
- identifying the causative agent (the pathogen)
what is the most clinically relevant classification of pneumonia?
- the clinical setting in which disease occurs
what are the 2 sub-classifications of anatomical classification of pneumonia
- lobar pneumonia
- bronchopneumonia
what is lobar pneumonia
- pathogen directly spreads from alveoli-alveoli via alveolar pores, usually throughout whole lung lobe.
what are 3 factors that can cause lobar pneumonia in adults?
- poor hygiene
- malnourishment
- alcoholics
what is bronchopneumonia?
when organisms colonise bronchi and then spread to the alveoli via bronchioles
what happens to affected areas in bronchopneumonia and what is it called when the whole lobe is affected.
- they initially consolidate locally rather than as a whole and eventually the whole lobe is affected.
- called confluent bronchopneumonia when whole lobe is affected.