Orthomyxoviridae

Question 1

Orthomyxoviridae
Pleomorphic, ENVELOPED/NONENVELOPED virus
_______ sense RNA/DNA genome w/ __ segments
Has to convert ___ to ___ sense, then sits on ribosomes and makes proteins (carries own ________)
_______ replication with budding from surface

Answer 1

Orthomyxoviridae
Pleomorphic, ENVELOPED virus
NEGATIVE sense RNA genome w/ 8 segments
Has to convert NEG to POS sense, then sits on ribosomes and makes proteins (carries own TRANSCRIPTASE)
NUCLEAR replication with budding from surface

Question 2

Minor changes over longer period of time in response to immune pressure, slow evolution, point mutations, changes in more than 2 epitopes.

Answer 2

Antigenic drift

Question 3

Major change; all 5 epitopes altered and there is no pre-existing immunity in population. Often originates in China because more intensive agriculture & high density population.

Answer 3

Antigenic shift

Question 4

What is necessary for HA to function? What enzyme is responsible?

Answer 4

Cleavage into HA1 and HA2

Host cell protease

Question 5

Equine Influenza
Two Diseases: 
Transmission:
Shedding: Incubation period=
Clinical Relevance:

Answer 5

Equine Influenza
Two Diseases: H7N7 (Equine 1) H3N8 (Equine 2)
Transmission: RESPIRATORY, AEROSOL INFECTION
Shedding: Incubation period= 1-3 DAYS
Clinical Relevance: UPPER RESP. TRACT SYMPTOMS, FEVER, 2º BACTERIAL INFECTION

Question 6

______ Influenza
Diseases: H5, H7 (virulent subtypes) ______ (Hong Kong bird flu)
Clinical Relevance: Respiratory signs, edema, diarrhea, pantropic spread, high mortality

Answer 6

AVIAN Influenza
Diseases: H5, H7 (virulent subtypes) H5N1 (Hong Kong bird flu)
Clinical Relevance: Respiratory signs, edema, diarrhea, pantropic spread, high mortality

Question 7

Canine Influenza

• Equine _____ virus jumped into dogs
• Clinical relevance:

Answer 7

Canine Influenza

• Equine H3N8 virus jumped into dogs
• Clinical relevance: RESPIRATORY SIGNS, MOSTLY MILD