upper respiratory tract infections Flashcards
how are infections transmitted in the respiratory tract
- respiratory secretions
- inhalation of drops or aerosols
what are the characteristics of a lower respiratory infection
- last longer
- can be more serious
- more difficult to treat
where do upper respiratory tract infections occur
- nose and throat
- middle ear
- auditory tubes
- ducts from the sinuses
- lacrimal canals
what pathogens infect the nares
Staphylococcus epidermidis
Corynebacteria
Staphylococcus aureus
what pathogens infect the nasopharynx
Streptococcus pneumoniae
Haemophilus influenzae
Neisseria meningitidis
what are the respiratory defence mechanisms
- filtration of air
- muco-cillary clearance system
- cough reflex
- reflex broncho- constriction
- alveolar macrophages
- antimicrobial peptide
- inflammatory cells
- adaptive immune response
what is the nasopharynx defence mechanisms
- nasal hair
- turbinates
- muccocillary apparatus
- IgA secretion
what is the oropharynx defence mechanism
- saliva
- sloughing of epithelium
- local complement production
- interference from resident flora
what are professional invaders
successfully infect the respiratory tract of healthy individuals
what are secondary invaders
only cause disease when host defence are already impaired
what respiratory tract infections are restricted to the surface of the epithelium
- pharyngitis
- common cold
- influenza
what respiratory tract infections spread to other parts of the body
- measles
- mumps
- rubella
how is pharyngitis caused
- encounter submucosal lymphoid tissue that form defensive ring around oropharynx
- sore throat due to muscosa infection or inflammatory and immune response
what causes pharyngitis
- common cold
- influenza
- Epstein barr virus - glandular fever
what are causes of a sore throat
- laryngitis
- tonsilitis
- strep throat
- glandular fever
- candida - thrush
what are complications of bacterial pharyngitis
- rheumatic fever
- poststreptococcsal glomerulonephritis
- peritonsillar abscess
how does the common cold cause infection
- transmission by aerosol
- surface molecule allow attachment to host cells or to cilia
- not washed away - initiates disease
what are the symptoms of rhinovirus
- viral respiratory illness
- wheezing
- increased risk of asthma
what are the symptoms of influenza
- sore throat
- chills
- headache
- fatigue
- muscle pains
how is influenza spread
airborne transmission
what are the complications of influenza
viral or bacterial pneumonia
how is measles spread
- highly infectious
- airborne transmission
what are the complications of measles
- ear infection
- diarrhoea
- pneumonia
- encephalitis - deafness
- respiratory and neurological complications
what causes mumps
paramyxovirus
