Module 5: Zoonotic Influenzas

Question 1

Which influenza virus is most likely to be transmitted zoonotically?

Answer 1

Influenza A virus

Question 2

What is defined as a family of negative-sense RNA viruses?

Answer 2

Orthomyxoviridae

Question 3

What type of influenza virus is the following describing?
- Infect birds and other animals as well as humans
- Are a source of seasonal influenza epidemics and all pandemics

Answer 3

A virus

Question 4

What type of influenza virus is the following describing?
- Infect humans only (maybe) and do not cause pandemics (can cause epidemics, but generally less severe than “A”)

Answer 4

B viruses

Question 5

What type of influenza virus is the following describing?
- Infect humans and swine and DO NOT cause pandemics
- Usually cause only mild disease

Answer 5

C viruses

Question 6

What type of influenza virus is the following describing?
- Identified in swine and cattle. Other species??

Answer 6

D viruses

Question 7

This is describing:
- (-) Stranded RNA Virus (mutate, no proof reading mechanism)
- lipid Enveloped pleomorphic virus (susceptible to disinfectants)
- Segmented Genome
- Hemagglutinin (18) and neuraminidase (11) are the major surface proteins

Answer 7

Influenza A virus

Question 8

The endemic infections of the influenza A virus are mostly seen in:

Answer 8

• Humans
• Birds (wild and domestic)
• Pigs
• Horses
• Dogs

Question 9

The sporadic infections of the influenza A virus are mostly seen in:

Answer 9

• Whales
• Seals
• Mink
• Camels
• Ferrets
• CATS

Question 10

Influenza A Virus
Minor antigenic changes over time due to point mutations
- Negative sense RNA virus
- RNA-dependent RNA polymerase
- No proof-reading during replication

Answer 10

Antigenic Drift

Question 11

Influenza A Virus
Major antigenic changes due to genomic reassortment
- Segmented Genome
- When one cell is infected by multiple influenza A viruses, gene segments can be shuffled

Answer 11

Antigenic shift

Question 12

Which is the best way to describe the concept of antigenic drift as it applies to influenza viruses?

Answer 12

Antigenic drift is the result of accumulating point mutations in the RNA segments of the influenza virus coding for HA and NA

Question 13

Which of the following reservoir species of influenza A virus maintains the greatest variation in HA-NA combinations resulting in the greatest diversity of virus subtypes?
- Pigs (swine influenza)
- Horses (equine influenza)
- Dogs (canine influenza)
- Humans (seasonal influenza)
- Birds (avian influenza)

Answer 13

Birds (avian influenza)

Question 14

Pandemic influenza occurs when a new strain of influenza emerges where:

Answer 14

1. there is little or no immunity to the virus in the human population
2. the virus is able to spread efficiently from person to person
   (a pandemic virus may cause mild to severe disease)

Question 15

(T/F) Wild birds are considered to be the primary reservoir for influenza A viruses

Answer 15

True

Question 16

Aquatic birds generally do not show any clinical signs of infection, but where do viruses replicate and shed into the environment?

Answer 16

Intestinal tract

Question 17

Disease in domestic poultry
____________ pathogenic viruses cause severe disease in domestic poultry and can cause mortality rates of up to 100% in affected flocks

Answer 17

Highly

Question 18

Disease in domestic poultry
____________ pathogenic viruses generally cause decreased egg production or mild upper respiratory disease in domestic poultry and do not typically cause death

Answer 18

Low

Question 19

Influenza A viruses cause outbreaks of respiratory disease in __________ herds

Answer 19

swine

Question 20

(T/F) Although mortality is relatively low, equine influenza spreads rapidly, can result in extended recovery time for infected animals, and can significantly harm equine populations, especially in the racing industry.

Answer 20

True

Question 21

• Is a recently recognized and emerging respiratory disease in dogs
• It was initially recognized in racing greyhounds and is now endemic in certain areas of the United States.

Answer 21

Canine Influenza

Question 22

What is considered to be the primary natural reservoir of influenza A viruses, but various subtypes have become established in different species, including humans, swine, horses, and dogs?

Answer 22

Wild birds (especially wild waterfowl)

Question 23

(T/F) While most influenza viruses are species-specific, the transmission of viruses from one species to another can occur

Answer 23

True

Question 24

Interspecies transmission can result in the formation of novel _________ or ___________ viruses

Answer 24

pandemic, panzootic