Viral infections and pandemic influenza

Question 1

What are the three types of influenza virus?

Answer 1

A, B, C

Question 2

What are the key antigenic sites of influenza?

Answer 2

haemagglutinin
neuraminidase
M2 ion channel
ribonucleoprotein

Question 3

What is the purpose of haemagglutinin?

Answer 3

virus binding and entry into cells

Question 4

What is the purpose of neuraminidase?

Answer 4

cuts newly formed virus loose from infected cells - increases the amount of virus released from cells

Question 5

Which types of influenza are the mainn human pathogens?

Answer 5

A and B

Question 6

Why can gene re-assortment occur easily in infections with flu?

Answer 6

because the viral genome is segmented into 8 ssRNA segments

Question 7

What can happen when an animal/human is co-infected with avian and human flu virus?

Answer 7

gene-swapping between the human and avian strains

Question 8

Why is influenza prone to mutation?

Answer 8

no proof reading mechanism

Question 9

What is antigenic drift and what does it cause?

Answer 9

minor antigenic variation

seasonal epidemics

Question 10

What is antigenic shift and what can it cause?

Answer 10

gene reassortment and major antigenic variation

pandemics

Question 11

What organisms can Influenza A infect?

Answer 11

pigs, cats, horses, birds and sea mammals

Question 12

Which influenza virus causes severe extensive outbreaks and pandemics?

Answer 12

A

Question 13

Which influenza virus is most often seen in children?

Answer 13

B

Question 14

How is influenza transmitted?

Answer 14

aerosols
coughs and sneezes
hand to hand
fomites

Question 15

What is the reduction number?

Answer 15

The average number of secondary cases generated by a primary case

Question 16

What are the complications of influenza?

Answer 16

bacterial pneumonia

Question 17

what conditions can increase the mortality risk in flu?

Answer 17

chronic cardiac and pulmonary diseases
old age 
Chronic metabolic diseases
Chronic renal disease
Immunosuppressed

Question 18

Give examples of supportive care offered

Answer 18

oxygenation
hydration
nutrition
maintain homeostasis
prevent/treat secondary infections

Question 19

What can antiviral mediations do to help?

Answer 19

reduce the severity and duration of symptoms

reduce risk of transmission to others

Question 20

What is an outbreak?

Answer 20

two or more linked cases

Question 21

what is an epidemic

Answer 21

more cases in a region/country

Question 22

What is a pandemic

Answer 22

epidemics that span international boundaries

Question 23

When does influenza peak in the northern hemisphere?

Answer 23

between jan and march

Question 24

Name some previous flu pandemics

Answer 24

Spanish flu - H1N1 - avian source
Asian flu
Hong Kong flu

Question 25

What factors increase the risk of spread of pandemics?

Answer 25

more travel more people intensive farming - more animals in contact with people and factory farming

Question 26

What developments may prevent pandemics?

Answer 26

better nutrition better supportive care vaccination antivirals

Question 27

How can avian flu be controlled?

Answer 27

``` cull affected birds quarantine disinfect farms vaccinate workers antivirals for poultry workers PPE ```

Question 28

What strain was swine flu?

Answer 28

H1N1

Question 29

What was swine flu a reassortment of?

Answer 29

swine, avian and human flu virus

Question 30

What drugs is swine flu sensitive to?

Answer 30

Oseltamivir and Zanamivir

Question 31

What does the containment phase involve?

Answer 31

identification of cases treatment of cases contact tracing large scale prophylaxis

Question 32

what does the Treatment phase involve?

Answer 32

treat cases only

Question 33

What age group were mostly affected by swine flu?

Answer 33

5-24 ie the under 65s

Question 34

List some infection control methods for prevention of spread of disease

Answer 34

``` hand hygiene coughing into a tissue mask, apron, gloves segregation of pts reduce social contact environmental cleaning ```

Question 35

During what time period does tamiflu need to be given to have the desired effect?

Answer 35

within 24-48 hours of contact

Question 36

List some popln wide interventions to reduce the spread of flu

Answer 36

``` travel restrictions restrictions of mass public gathering schools closure voluntary home isolation voluntary quarantine of contacts of known cases screening of people entering UK ports ```