Orthomyxoviruses

Question 1

Main Example

Answer 1

Influenza Virus

Question 2

General characteristics (2)

Answer 2

Enveloped

Linear ssRNA genome

Question 3

Genome

Answer 3

Consists of 8 segments (allows combinations/rearrangements)

Question 4

Surface Glycoproteins

Answer 4

HA and NA

Responsible for pathogenicity

Question 5

How many subtypes?

Answer 5

In birds, animals, human: 15 HA and 9NA

In humans only: 4HA and 2NA

Question 6

How many types?

Answer 6

3

A, B, C

Question 7

Cold Vs Flu

Answer 7

Cold = Rhinoviruses, Coronaviruses, Adenoviruses
Flu = Influenza virus

Cold - Rare fever, vomitting, nausea, diarrhea

Question 8

Uncomplicated Influenza

Answer 8

Caused by A or B

Influenza C causes common cold illness, Coryza

Question 9

Pneumonia

Answer 9

Only in babies, elderly, Immunocompromised

Enhances susceptibility of patients to bacterial superinfection (streptococcus pneumoniae)

Question 10

Reye’s syndrome

Answer 10

Acute encephalopathy of children and adolescents

Question 11

Antigenic Drift (4)

Answer 11

Influenza A and B

Epidemics

Can occur every year

Main reason why people can get flu more than one time

Question 12

Antigenic shift (4)

Answer 12

Major antigenic change of either HA or NA antigens or both

Occurs either between 2 A viruses or 2 B viruses, not a mixture of A and B

Pandemic with high mortality

Occurs every 8-10 years

Question 13

Spanish flu

Answer 13

H1N1

1918-1919

Question 14

Asian Flu

Answer 14

H2N2

1957-1958

Question 15

Hong Kong Flu

Answer 15

H3N2

1968-1969

Question 16

Swine Flu

Answer 16

H1N1

2009-present

Question 17

Types of Influenza vaccines (3)

Answer 17

Inactivated influenza vaccine

Live attenuated influenza vaccine

Recombinant influenza vaccine

Question 18

Trivalent vaccine

Answer 18

Protects against:
1- Influenza A (H1N1)

2- Influenza A (H3N2)

3- Influenza B

Question 19

Quadrivalent vaccine

Answer 19

Protects against:
1- Two influenza A

2- Two influenza B