Common viral infection affecting the respiratory tract. Flashcards
define profuse
very plentiful
Define purelent
consisting of, containg or discharging pus
clinical site fpr infection?
Rhinitis, otitis media, sinusitis, pharyngitis/tonsillitis, laryngo-tracheo- bronchitis (croup),
bronchitis, bronchiolitis, bronchopneumonia and pneumonia
Name common viruses
common viruses:
Rhino virus, Enteroviruses, Parainfluenza virus, Respiratory Syncytial Virus, Human
metapneumovirus, Adenoviruses
From Nose the alveoli the respiratory tract is ?
continuum
some micro-organisms are restricted from the surface epithelium.
Rhinoviruses
Influenza
Streptococci in throat
Chlamydia (conjunctivitis)
Diphtheria
Pertussis
Candida albicans (thrush)
others spread in the body before returning to the respiratory tract, larynx.
Measles, mumps, rubella
EBV, CMV
Chlamydophila psittaci a
Q fever
Cryptococcosis
Rhinitis
rhinitis is a common cold
takes about 1- 3 days
what are prodromal symptoms of rhinitis?
Headache, sore, fullness of nose
Pharyngitis/Tonsillitis
- 70% viral
- Including Adenoviruses
- Some viruses can cause vesicles (blisters) ulcers.
Infection of the middle ear and of sinuses (frontal, ethmoid, sphenoid, maxillary sinuses? what aare they called?
Otitis media and sinuses.
Laryngitis/laryngotracheitis
In children difficult to distinguish due to very close anatomy, so sometimes called laryngotracheobronchitis
* In adults maybe can separate laryngitis (hoarse voice) and tracheitis (sore throat and cough)
* In children can present as croup with stridor- a particular high pitched sound with inspiration and sometimes
even on expiration – due to narrowed airway
Chronic bronchitis
not infective
due to irritation from smoking,but also pollution,fumes inhaled dust.
what virus accounts about 30% of the community acquired pneumonia?
Viral Pneumonia.
mainly reach lungs via resp. tract
Site of infection of Rhinovirus?
Rhinoviruses tend to infect the nose because they prefer slightly cooler temperatures for replication
why does someone get
laryngitis, and the other family member only a mild rhinitis?
We all know family members who get much milder version of viral respiratory infection,
probably many viral infections are asymptomatic in older children or healthy adults
list common viruses
Respiratory Syncytial Virus, Human metapneumovirus, Parainfluenza
virus, Adenoviruses, Enteroviruses, Rhino virus,
define syncytia?
a multinucleate mass of
cytoplasm resulting from the fusion of cells.
which virus is highly infectious and most children in the first yr of life
syncytial virus
and the major cause of bronchiolitis in infants
how is long term consequences of syncytial virus infection on lung is being recognized?
Increased wheezing
which virus occurs mainly in spring as opposed to autumn for RSV?.
Human metapneumovirus
classic symptoms of Rhinovirus
nasal discharge, nasal obstruction, cough, and/or a sore or scratchy throat lasting 5- 7 days
children are usually sicker, often fever, and last longer 10 days or so
how is rhinovirus transmitted?
of infected droplets reaching nasal mucosa or conjunctiva
Laboratory diagnosis of viral infections
Culture of virus
* Detection of viral antigens in clinical sample by microscopy
demonstrating antibody responses to infection in serum.
detection of viral nucleic acids
viral culture:
Viruses only replicate in living cells (Don’t grow on laboratory media)
* Traditional diagnosis in cell culture systems- slow (days to weeks) labour intensive
Detection of viral antigens:
Electron microscopy (viruses not visible on light microscopy), useful for defining morphology in detail,
but not for routine diagnosis
* Immunofluorescence microscopy: using fluorescent labelled antibodies to visualise viral antigens, also
Treatment of viral respiratory infections
What is the difference between an enveloped and unenveloped virus?
Enveloped virus is surrounded by host derived biological membrane more
susceptible to physical alterations, e.g. drying, heat, acid, etc therefore easier to
control spread of enveloped virus by various hygiene measures. But also may
provoke lesser inflammatory response during course of infection in hos
What impact does it have on risk of transmission of infection?
infection
