lower respiratory infections

Question 1

the two most common viruses causing LRTI?

Answer 1

influenza virus and respiratory syncytial virus (RSV)

Question 2

influenza virus surface glycoproteins?

Answer 2

hemagluttin and neuraminidase

Question 3

influenza virus types and subtypes

Answer 3

3 types: A,B,C based on internal NP proteins

only type A has subtypes based on hemagluttin and neuraminidase.

Question 4

influenza virus symptoms?

Answer 4

needs a systematic symptom eg fever and a respiratory symptom eg cough, sore throat
-strips the respiratory tract of the 2 innate defences, cilia and goblet cells.

Question 5

complications of influenza virus?

Answer 5

primary viral pneumonia (appears fibrous) and secondary bacterial pneumonia (the secondary bacterial infection as result to treatment)

Question 6

why does the influenza virus cause epidemics every winter?

Answer 6

antigenic drift- only in influenza A+B types when there are random mutations for the hemagluttin and neuraminidase
antigenic shift- only in influenza A type
when there is genetic reassortment between the human and non-human virus leading to a new subtype.

Question 7

what does the respiratory syncytial virus (RSV) cause?

Answer 7

causes LRTI in infants such as bronchitis and pneumonia.