URTI

Question 1

what are some examples of upper respiratory tract infections?

Answer 1

1) Epiglottitis
2) Laryngitis
3) Tonsilitis
4) Pharyngitis

Question 2

What is the mechanism for professional invaders?

Answer 2

1) adhesion to the mucosa
2) avoiding host defence
3) damaging local tissue by the production of toxins

Question 3

What is the mechanism for secondary invaders of URT?

Answer 3

1) they cause disease when host defences are impaired
2) compromised immune response due to: cancer chemo, AIDS
3) foreign body: they enter due to medical tubes/ medical ventilation

Question 4

What is the clinical manifestation for a common cold (coryza)

Answer 4

1) nasal discharge, sneezing and sore throat, temperature
2) may cause infection of larynx and trachea
3) incubation period = 2-4 days

Question 5

What are some causative organisms for the common cold (coryza) ?

Answer 5

Rhinovirus, RSV, Coronavirus

Question 6

What is the treatment for a common cold?

Answer 6

Supportive medicine: paracetamol

Question 7

What is the manifestation for oral candidiasis (thrush) ?

Answer 7

1) changes in flora can upset the balance allowing for overgrowth of fungi
2) raw inflamed mucous membranes + white fungal plaques

Question 8

What are some predisposing factors for oral thrush?

Answer 8

contraceptive pills, systemic steroids, chemotherapy, HIV

Question 9

What is the causative microorganism for oral thrush?

Answer 9

Candida albicans

Question 10

What is the clinical manifestation for Sinusitis and the causative organisms?

Answer 10

1) facial swelling and localised tenderness
2) usually viral, but may occur due to secondary invaders such as streptococcus pneumoniae

Question 11

What is the treatment for oral thrush?

Answer 11

1) Nystatin/ clotrimazole pastilles
2) for severe oral thrush: fluconazole (inhibits the growth of candida by disrupting the production of ergosterol which is a component of fungal cell membranes)

Question 12

What is the treatment for Sinusitis?

Answer 12

NO TREATMENT FOR VIRAL INFECTION

Bacterial: amoxicillin, Doxycycline, erythromycin

Question 13

What are the clinical manifestations and causative microorganisms for pharyngitis/ tonsillitis

Answer 13

1) fever, sore throat, cervical lymphadenopathy (swelling of lymph nodes in the neck), discharge
2) Viruses: adenovirus
Bateria: streptococcus pyogenes

Question 14

What is the treatment for viral tonsillitis?

Answer 14

Pain relief medication, ibuprofen, humidifier, salbutamol (inhaler)

Question 15

What is the clinical manifestation and causative virus for viral tonsillitis?

Answer 15

1) Scratchy sore throat, stuffy or runny nose, purulent discharge
2) rhinovirus, adenovirus, influenza virus

Question 16

What are the complications associated with streptococcal tonsillitis?

Answer 16

1) peritonsillar abscess
2) rheumatic fever
3) glomerulonephritis
4) scarlet fever

Question 17

What is the mechanism of streptococcal pathogenicity?

Answer 17

1) ability to colonise the host and invade tissues
2) ability to bypass host defences
3) ability to damage host through production of toxins

Question 18

What is the function of the F protein in adhesion?

Answer 18

1) binds to fibronectin which allows S.pyogenes to attach to epithelial cells in the throat/skin -> allows bacteria to anchor itself to host tissues
2) facilitates invasion and initiating infections

Question 19

What is the role for the M protein?

Answer 19

1) plays a role in immune evasion
2) binds to fibrinogen -> activates platelets and leukocytes = inflammation
3)interferes with phagocytosis by maintaining survival of bacteria
4) is a key virulence factor -> causes rheumatic fever
5) found in group A strep

Question 20

What is the purpose of the hyaluronic acid capsule?

Answer 20

1) it is identical to human substance and is used to avoid immune detection

Question 21

What are some virulence factors secreted by strep?

Answer 21

streptomycin O
DNAase
streptokinase
hyaluronidase

Question 22

Which toxins are responsible for scarlet fever?

Answer 22

streptococcal pyrogenic exotoxins AKA superantigens

Question 23

Which blood culture should be used for S. Pyrogens?

Answer 23

Blood agar enriched