18. Viral diseases

Question 1

name 2 points of entry for viruses

Answer 1

bloodborne

respiratory

Question 2

give an example of a blood borne virus

Answer 2

hepatitis B

Question 3

where does hepatitis B replicate

Answer 3

in the liver, it circulates the blood stream until it reaches the liver

Question 4

name a respiratory virus that spreads to the rest of the body

Answer 4

measles

Question 5

why doesn’t bird flu spread in humans

Answer 5

bird flu binds to cells that present carbohydrates on their surface - these are found deep in the respiratory tract

Question 6

why do seasonal flu viruses Infect better than bird flu

Answer 6

bind to cells in the upper respiratory tract - means they can infect you directly through the nose

Question 7

how can diseases be transmitted

Answer 7

direct contact
aerosol
vector borne
sharing needles
sexually

Question 8

what are fomites

Answer 8

surfaces on which pathogens can be found

Question 9

what occurs in the prodromal infectious period

Answer 9

the patient has no symptoms yet are infective

Question 10

describe the stages of HIV infection

Answer 10

1. flu like symptoms
2. CD4 t-cells decline and immune system declines, anti-HIV antibodies rise
3. anti-HIV can no longer be produced, virus become prevalent and can survive outside t-cells
4. virus reproduces uncontrollable = fatal

Question 11

how does influenza enter the body

Answer 11

via the respiratory tract

Question 12

which 2 influenzas are included in the seasonal vaccinen

Answer 12

influenza A and B

Question 13

why is influenza C & D not included in the seasonal vaccine

Answer 13

causes milder infections

Question 14

what is the molecular sequence for:
spanish flu
hong kong flu

Answer 14

H1N1

H3N2

Question 15

what launches new pandemics of infleunza

Answer 15

antigenic shift

Question 16

how can new strains be rpduced

Answer 16

once a animal virus is in a human host it can reassort with human viruses

these produce hybrid strains that are responsible for new pandemics

Question 17

what is it assumed Spanish flu was a product of

Answer 17

a bird flu reassorting with a human virus

Question 18

what is the incubation period

Answer 18

the number of days between when your infected and when symptoms may appear

Question 19

what is the serial interval

Answer 19

the time between symptoms occurring in an initial patient and the onset of symptoms in a secondary infected individual

Question 20

name 2 diseases spread by the faecal oral route

Answer 20

hepatitis A

foot and mouth disease

Question 21

what is the vector for foot and mouth disease

Answer 21

humans transmitting the pathogens from farms

Question 22

when are viral titres at their highest in hepatitis A

Answer 22

following infection before the onset of clinical illness

Question 23

what is the vector for yellow fever virus

Answer 23

aedes aegypti

- insect vector

Question 24

why is the issue of climate change important in disease spread

Answer 24

disease such as yellow fever virus are transmitted via insects suited to warmer climates

as temps climb in the north, the insect vector can survive and transmit the disease to these new regions

Question 25

what is the most common cause of meningitis in europe

Answer 25

sandfly fever virus

Question 26

how is HIV transmitted

Answer 26

sexually and bloodborne

Question 27

what is the hypothesised origin of HIV

Answer 27

simian immunodeficiency virus

- the chimp meat trade allowed SIV into a human host where it reassorted to produce HIV

Question 28

where are the following HIV genotypes most commonly found?

• genotype A
• genotype B
• genotype C

Answer 28

A = russia and africa
B = europe & america
C = india

Question 29

which virus is responsible for the common cold

Answer 29

rhinovirus

Question 30

how is rhinovirus transmitted

Answer 30

fomites
direct contact
aerosol

Question 31

where does rhinovirus colonise

Answer 31

the upper respiratory tract

Question 32

where dos hepatitis colonise

Answer 32

the liver

Question 33

how is hepatitis transmitted

Answer 33

in the blood or bodily fluids of an infectious person