+ sense RNA viruses

Question 1

List all the families of + strand RNA viruses (5)

Answer 1

Picornavirus
Calicivirus and Hep E
Flavivirus
Togavirus
Coronavirus

Question 2

Picornavirus family list (3)

Answer 2

Rhinovirus
Hep A virus
Enterovirus

Question 3

List the Calicivirus and Hep E

Answer 3

Noroviruses

Hep E virus

Question 4

List the Flavivirus family

Answer 4

Flavivirus genus (5)
Hepacivirus
Pegivirus
Pestiviruses

Question 5

List the Togavirus family

Answer 5

Rubella virus
Arbovirusese including;
alphaviruses

Question 6

All the + sense RNA viruses are enveloped except these two

Answer 6

Picornaviruses and Calicivirus/hep E

Question 7

All the + sense RNA viruses are icosahedral except

Answer 7

Coronavirus is helical

Question 8

What are the differences between togavirus and flavivirus

Answer 8

Togavirus is slightly larger and there are some replication differences

Question 9

All of the following is true for Picornavirus cell cycle EXCEPT
A. the cell ribosomes bind to 5’ IRES in order for mRNA to be translated
B. genome is translated into multiple proteins
C. RDPD transcribes the neg strand and then copies it to pos strand
D. the capsid is assembled in the cytoplasm
E. Early mRNA encode structural proteins (including capsid) and late mRNA encode nonstructural proteins (including RDRP)

Answer 9

B is false: genome is translated into a single polyprotein which is cleaved by viral protease

Question 10

List the infections of piconaviruses

Answer 10

Rhinovirus- common cold
Hepatitis A- liver
Poliovirus- enteroviral

Question 11

What is true about the pathogenesis of picornaviruses?

A. Rhinovirus (140 strains) causes the common cold and elicits a strong immune response, covering a variety of strains
B. Hepatitis A is highly stable, infectious cause of chronic fever, NVD and jaundice, especially in the young
C. Poliovirus is an enterovirus that cuses viremia and flaccid paralysis; a good example of “tip of the iceberg”
D. All Picornaviruses cuase persistent infections in normal health host.

Answer 11

C is true
A- False: weak immune response and immunity against 1 does not protect against others.
B- False: Hep A inf is not chronic and severe disease is more common in adults.
D. False. the opposite is true

Question 12

There is no treatment available for picornavirus but ___ can be prevented with 2 types of vaccines: ____ is a killed vaccine and ____ is an attenuated vaccine

Answer 12

Polio
Salk
Sabin

Question 13

True or false: the Sabin vaccine for Polio protects against GI infection

Answer 13

False: it is attenuated

Question 14

The major diseases caused by Caliciviruses and Hep E:

Answer 14

Gastroenteritis (Norovirus)

Hepatitis

Question 15

Which of the following is FALSE
A. Norovirus is the #1 cause of adult non-bacterial diarrhea
B. Hepatits E is rarely fatal in the general population, but is 50% fatal in pregnant women
C. Caliciviruses and Hep E are transmitted through fecal-oral and person-to-person routes
D. Norovirus is easy to contain and replicate due to its instability
E. Hepatitis E can cause chronic infections in the immune compromised and kidney disease in transplant recipients.

Answer 15

D. is false: Norovirus is very stable and thus difficult to contain or replicate in culture. Sanitation is the hallmark for prevention.

Question 16

Which of the following is true about the Flavivirus family?
A. They amplify in arhtropods and spread through humans
B. Encephalitis is caused by JEV, TBEV, WNV and Dengue fever
C. Hepacivirus is an acute infection of the liver that never progresses.
D. Pegivirus cuases serious disease and leads to hodgkins lymphoma
E. Yellow fever virus can cause flu-like illness, encephalitis, hemorrhagic fever, and hepatitis

Answer 16

E. true

A: false. they amplify in insects/mammals and spread through arthropods

B: false: Encephalitis is caused by JEV, TBEV, WNV, and YFV, not dengue. Dengue virus causes dengue fever or dengue hem fever/shock syndrome- needs 2nd inf of a diff serotype.

C. False: Hep C causes chronic inf (20% dev cirrhosis in 20 yrs) that can lead to hepatocellular carcinoma in 26 yrs. It slowly progresses or doesn’t progress

D. false: Pegivirus causes no disease and increases risk of non-hodgkins lymphoma

Question 17

True or false: There are no tx available for flavivirus family

Answer 17

False: Hep C can be tx: very expensive but effective. No tx for other flaviviruses

Question 18

The flavivirus cell cycle is very similar to the picorna virus cycle except the enveloped virus buds into the ___ and uses complex entry with multiple receptors

Answer 18

Internal membrane of ER, not PM

Question 19

Rubella, a togavirus is transmitted through the ____ system and causes ____ and ___ while congenital rubella’s route is _____ and causes (4) ____, ____, _____, and ____

Answer 19

Rubella: respiratory; mild systemic viremia and jaundice

Congenital: intrauterine; deafness, blindness, Mental retardation, and heart disease

Prevent with MMR (attenuated)

Question 20

Coronaviruses have more than ___ strains, ___ of them cause the common cold. They can also cause more severe diseases like ____ and ___

Answer 20

5:3
SARS: MERS