Influenza

Question 1

what was a consequence of getting swine flu shots in the 1970’s?

Answer 1

Guillan Barre

-hundreds of cases

Question 2

why is it so easy for influenza to mutate?

Answer 2

segmented RNA genome

• can swap out genes really simply
• can have genes from different virus

Question 3

main type of influenza

Answer 3

type A (epidemics)
Type B (non-epidemic)

Question 4

what are the neutralizing targets for influenza?

Answer 4

hemagglutinin

neuraminidase

Question 5

since influenza is RNA viruses, what does that mean?

Answer 5

high mutation rate

Question 6

antigenic drift

Answer 6

• change their sequences of H1 and N1 proteins from year to year in process of antigen drift
• ensures host wont have neutralizing antibodies to future stains

Question 7

antigenic shift

Answer 7

causes pandemic

• each gene of influenza is encoded on a separate strand of RNA
• when virus enveloped is formed, gene segments from different viruses that have infected the same cell can be incorporated into virus
• acquires new hemagglutinin or neuraminidase genes

Question 8

transmission of influenza

Answer 8

need large droplets

• sneezing, coughing
• large droplets dont stay suspended in hair-> close contact

Question 9

clinical illness of influenza

Answer 9

fever
headache
myalgia
fatigure
cough
sore throat
nasal discharge
fatigue
weakness

Question 10

not typical symptoms of influenza

Answer 10

N&V, diarrhea

Question 11

Complications for Influenza

Answer 11

Viral pneumonia
Bacterial pneumonia-> strep p. and staph aureus
Myositis and rhabdomyolysis
Myocardial infarction
Encephalitis, encephalopathy
Reyes syndrome-> aspirin not used anymore really except to prevent heart attacks

Question 12

Unique things to Spanish flu

Answer 12

infected started out fine but then got worse

-bacterial pneumonia most common cause of death

Question 13

Unique to “Bird” flu

Answer 13

• affects primarily in children and young adults
• very high mortality
• respiratory illness
• diarrhea and neurological components
• little person to person transmission

Question 14

Avain influenza H7N9

Answer 14

-china
elderly
severe respiratory illness

Question 15

H3N2 variant influenza

Answer 15

Indiana state fairs

• close contacts with pigs
• mild disease
• no sustained transmission
• 2009 H1N1 and pig H3N2 strain

Question 16

Diagnosis of influenza

Answer 16

• rapid flu tests-> ELISA, look for antigen for strain

- only 60% sensitive

Question 17

Best test for diagnosis

Answer 17

RT-PCR, very sensitive (90%)

Expensive

Question 18

Gold standard of diagnosis

Answer 18

Viral culture-> takes too long though

Question 19

Treatment

Answer 19

• antiviral doesn’t work

- resistant to amantadine and rimantadine

Question 20

New drugs that influenza not resistant too

Answer 20

-inhibit neuraminidase-> stop spread throughout the body
oseltamivir
zanamivir

Question 21

when does medication need to be taken by?

Answer 21

Within 48 hours of symptoms onset

-at best reduces symptoms by 1-2 days

Question 22

Zanamivir

Answer 22

• oral inhalation

- IV form

Question 23

how does antigenic drift effect vaccines?

Answer 23

-have to make new vaccines every year

Question 24

How do they guess what new vaccines to make?

Answer 24

-educated guess

Trivalent vaccine, but three in there: usually 2 A strains and 1 B strain

Question 25

How are vaccines grown?

Answer 25

in eggs

Question 26

How are vaccines are inactivated?

Answer 26

-purified (to separate out viral components) and inactivated with formaldehyde

Question 27

What is a split vaccine?

Answer 27

-just has HA and N antigens in it

Question 28

Side effects from vaccine

Answer 28

• Guillain-Barre syndrome (mainly seen in 1976’s, rare now)
• pain at injection site
• muscle aches (causes low grade release interferon)
• maybe a low grade fever

Question 29

who should take the live-attenuated vaccine

Answer 29

-less than 50

Question 30

vaccine effectiveness

Answer 30

• most effect in children

- in those older than 65-> not very effective