Upper Respiratory Tract Infections Flashcards
What is the upper respiratory tract?
Everything above the trachea e.g. the nose, paranasal sinuses, middle ear, nasopharynx, oropharynx, laryngopharynx, tonsils and adenoids
Is the upper respiratory tract sterile?
No, it’s colonised by a variety of normal flora
What causes the vast majority of upper respiratory tract infections?
Viral infections
What causes a ‘cold’?
Caused by many strains of rhinovirus and sometimes coronaviruses
What is the main virus implicated in causing a cold?
Rhinovirus
What may follow as a result of a cold?
Transient opportunistic bacterial infection such as otitis media in children and sinusitis in adults
How is a ‘sore throat’ referred to medically?
Pharyngitis
What may cause a sore throat?
Pharyngitis may be caused by group A streptococci infection
What are the four main viruses that are implicated in the cause of upper respiratory tract infection
Rhinovirus, respiratory syncytial virus, parainfluenza virus and adenovirus
What are two important bacterial causes of upper respiratory tract infection?
Group A streptococci (pyogenes) infection and haemophilia influenza type B
What is quinsy?
Peritonsillar abscess
What types of antibiotic are given to fight group A streptococci infection?
Penicillin (all Streptococci are sensitive to this) or erythromycin
What are the potential complications of untreated pharyngitis?
Rheumatic fever and/or glomerulonephritis
What is otitis media?
A middle ear infection that most often effects children
What is the cause of otitis media?
This commonly occurs due to viral infection causing dysfunction of the Eustachian tube which allows for opportunistic bacterial infection
What is sinusitis?
Inflammation of the air sinuses in the head due to viral or bacterial infection due to the overgrowth of the normal sinus flora
What may cause sinusitis?
Overgrowth of the normal sinus flora such as treptococcus pneumoniae, haemophilus influenza and moraxalla catarrhalis that leads to infection
What is epiglottitis?
Inflammation of the epiglottis which has a role in closing off the trachea to allow swallowing of food
What is the most common cause of epiglottis?
It is almost always caused by a bacterial infection
Why is epiglottitis a medical emergency?
It can lead to asphyxiation if it becomes so inflamed that it prevents the opening to the trachea from being available
How is epiglottitis treated?
Airway opening (either via intubation or tracheostomy), antibiotics (cefotaxime or ceftriaxone), prophylaxis for unimmunised household contacts and immunisation of index cases
What is whooping cough?
A highly contagious bacterial disease that appears similarly to a cold
What is the cause of whooping cough?
Bordatella pertussis bacterial infection
What are the symptoms of whooping cough?
To begin there is just a cough, but after 2 weeks there will be severe coughing with a typical whoop on vigorous inspiration
Describe the treatment of whooping cough
Erythromycin is given in the first week (catarrhal phase) to decrease transmission
How can whooping cough be prevented?
Acellular vaccines – these contain an inactive form of the pertussis toxin alongside filaments of haemaglutinin, agglutinogens and an outer membrane protein
What is diphtheria?
Diphtheria is a potentially fatal contagious bacterial infection that mainly affects the nose and throat, and sometimes the skin.
What causes diphtheria?
Corynebacterium diphtheriae
Outline the pathophysiology of diphtheria
Normally EF-Tu is a molecule that is required to transfer tRNA to the growing polypeptide in gene translation, diphtheria toxin binds to EF-Tu and inactivates it, inhibiting protein synthesis
How is diphtheria treated?
Use of antitoxin
What is glandular fever?
Infectious mononucleosis (mono) which is a viral infection that effects the upper respiratory tract
What is the cause of glandular fever?
Epstein-Barr virus
What are the symptoms of glandular fever?
Tonsilar exudates, gross pharyngeal swelling, hepatosplenomegaly
How is adenovirus transmitted?
Via droplets, fomites and ingestion
What is the action of adenovirus?
It effects he mucous membranes of the • eye, respiratory and GI tract and local lymph nodes become enlarged and tender
What can adenovirus infection lead to?
o Epidemic kerato-conjunctivitis – a mild trauma to the eye may facilitate damage and lead to infection of the cornea e.g. if towels are shared
o Pneumonia – adenovirus infection may follow measles and may cause a severe destructive pneumonia
o Acute respiratory disease (ARD)
What is main pathogen involved in respiratory infections in childhood?
Respiratory syncytial virus
Describe the structure of paramyxoviruses
Apears similarly to influenza virus , it is roughly spherical with an inner helical nucleocapsid which contains protein and the envelope of the virus is covered with haemaglutinin and neuroaminidase
How may infection with influenza virus be treated?
With neuraminidase inhibitors e.g. zanamavir or oseltamivir
