respiratory viruses and atypical respiratory pathogens

Question 1

types of infection

Answer 1

surface

systemic

Question 2

surface infections

Answer 2

local spread in the local area where the infection foci is

short incubation e.g. cold

Question 3

systemic infection

Answer 3

spread from musical site of entry to other site on the body
long incubation
returns to surface for final shedding stage e.g. measles

Question 4

professional invadesr

Answer 4

infect healthy respiratory tract

Question 5

secondary invaders

Answer 5

infect compromised tract

infection following on e.g. from covid

Question 6

infections of the nasoparynx

Answer 6

rhinitis, sinusitis
transmission by aerosol
not systemic in healthy peiople
in the URT

Question 7

infections of the nasopharynx steps

Answer 7

1) infection of cialted cells via adherence via receptor
2) enters the cell via adsorption, then replicates
3) infect cells, spread to neighbouring areas
4) overwhelm the cell its in, lyses cell releasing the virus more
5) inflammatory response results in classic cold symptoms
6) then regrowth occurs, returning to normal

Question 8

viral structure of common cold viruses

Answer 8

icosahedral symmetry
non envolped
capsid (protein coat)
inside with nucleic acid
attach via the adhesions on end of penton fibre

Question 9

pharyngitis and tonsilities

Answer 9

complications of common colds due to surrounding infections

viral usually

Question 10

mumps

Answer 10

paramyxovirus
air borne spread
complications - orchitis

Question 11

laryngitis and tracheitits often caused by

Answer 11

by parainfluenza viruses, adenoviruses and influenza

can lead to croup in childre

Question 12

bronchitis and bronchilotis

Answer 12

viral causes (rhinoviruses, coronaviruses, influenza)

Question 13

respiratory syncytial virus

Answer 13

can cause bronchiolotis
aerosol transmisstion
pathlogy creates large fused cells

Question 14

symptoms of infants of respiratory syncytial virus

Answer 14

cough
cyanosis
rapid respirator rate
penumonia

Question 15

treatment of respiratory syncytial virus

Answer 15

hydration

bronchodilators

Question 16

influenza virus

Answer 16

orthomyxoviridae
aesosol
Initial infection
- virus attaches to sialic acid receptors on epithelial cells via viral HAH protein
1-3 days
- liberated cytokines result in systemic chills, malaise, fever and muscle aches, runny nose and cough

Question 17

influenza virus structure

Answer 17

two surface glycoprotiens
1) HA - haemagglutinin binds to sugar
source of antigenic variation
2) NA neuamindase
involved in breatking out of cell/release of virus during budding

Question 18

types of influenza

Answer 18

A
yearly epidemics
important animal reservoirs in birds and pigs
B
yearly epidemics
C 
- minor repsiraotry illness

Question 19

viral uptake of HA (from influenza)

Answer 19

1) HA mediates binding to sialic acid containing receptors
2) internalised by endocytosis
3) endosome acidified – HA conformation alters M2 ion channel important here
4) HA mediated fusion of viral envelope and endosome membrane
5) viral RNA ad polymerases delivered into cell
6) replication

Question 20

antigenic drift influenza

Answer 20

• small point mutations in HA/NA that accumulate in population over time
• result in new variant viruses that can reinfect individuals
• source of yearly flu epidemics worldwide
• all types of influenza

Question 21

pneumonia

Answer 21

often secondary to preceding damge- cystic fibrosis or influenza

children - mainly viral
adults
- mainly bacteria

Question 22

what do symptoms of COVID relate with

Answer 22

ACE 2 expression

Question 23

structure of COVID virus

Answer 23

• trimeric spike protein binds to ACE2 (made up of 3 copies of the protein)
• Angiotensin converting enzyme 2
• present in airway cells, blood vessels, cardiac, CNS
  embeds in capsid envelope