Micro: Viruses

Question 1

Naked dsRNA virus.

Answer 1

Rotavirus

Question 2

Transmission of rotavirus.

Answer 2

Fecal-oral

Question 3

Naked RNA virus, cruise ships.

Answer 3

Norwalk virus

Question 4

Naked DNA virus, swimming pools, conjunctivitis, diarrhea.

Answer 4

Adenovirus

Question 5

IC pts., organ transplants, ulcers, bloody diarrhea.

Answer 5

CMV

Question 6

What about rotavirus allows one child to be infected more than once?

Answer 6

Segmented RNA allows it to do Antigenic shift

Question 7

Main virulence factor of Rotavirus and what it does.

Answer 7

Viral Protein 7 (VP7)

-induces formation of neutralizing Abs

Question 8

How does Rotavirus cause diarrhea?

Answer 8

NSP4 protein acts like a toxin to cause calcium influx into cells. Results in chloride, sodium, and water efflux resulting in diarrhea

Question 9

Type of vaccine for Rotavirus

Answer 9

Oral live

Question 10

Yellow Fever vector

Answer 10

Aedes mosquito

Question 11

Viral characteristics of yellow fever

Answer 11

RNA, enveloped

Question 12

Symptoms of Yellow Fever infection.

Answer 12

Jaundice, dark urine, pale stools, black vomit

Question 13

Pathogenesis of Yellow fever.

Answer 13

• Virus invades hepatocytes
• Hepatocytes produce MHC I
• CD8 T cells recognize MHC I and kill hepatocytes
• results in jaundice
• jaundice causes all the other symptoms

Question 14

Type of vaccine for yellow fever.

Answer 14

Live Attenuated

Question 15

Pathogenesis of Hep A virus.

Answer 15

Cell Mediated Immunity (CMI) causes the hepatitis.

-children are at risk of chronic infection because they have an immature immune system which allows the virus to survive

Question 16

Type of vaccine for Hep A

Answer 16

Killed vaccine

Question 17

What are Dane particles?

Answer 17

Infectious form of Hep B virus containing surface Ag proteins surrounding viral DNA and RT enzyme

Question 18

Name the 3 antigens present in a Hep B infection and what they can tell us thru serology.

Answer 18

Surface antigen - patient currently infected
Core antigen - patient currently infected
Envelope antigen - patient infected and has active viral replication occuring

Question 19

What do the Surface antigen antibodies and core antibodies tell us about a patient with Hep B?

Answer 19

Anti-sAg: patient received vaccine or cleared a previous infection

Anti-cAg: patient cleared a precious infection

Question 20

What dictates if a Hep B infection will be acute or chronic?

Answer 20

Patients CMI. A strong immune response will show an acute attack with symptoms after just a couple weeks after infection. Then the body usually clears the virus.

A weak immune response leaves the liver intact initially but does not kill the virus, so the virus remains for longer than 6 months

Question 21

Type of vaccine for Hep B

Answer 21

Genetically engineered to only have the Surface Ag.

Question 22

2 treatments for Hep B.

Answer 22

1. RT inhibitor

2. INF-alpha (inhibits Elongation Factor 2 preventing protein synthesis)

Question 23

What are the 3 C’s of Hep C?

Answer 23

Chronic, cirrhosis, cancer

Question 24

How does Hep C get into hepatocytes?

Answer 24

Coats itself with LDL and VLDL which recognizes surface receptors on the hepatocytes

Question 25

Treatment for Hep C infection.

Answer 25

Recombinant INF-alpha

and ribavarin

Question 26

Why does Hep D need Hep B do infect the liver?

Answer 26

Hep D will use the surface antigens made by Hep B and sent out into the blood.

Question 27

What is the difference between a Hep B and Hep D coinfection vs. superinfection?

Answer 27

Co infection occurs when the two viruses infect the body at the same time. The Hep B surface antigen takes longer to be made and provide Hep D with a way to enter hepatocytes.

Superinfection occurs when Hep B infection is followed by Hep D and the surface antigens of B are already disseminated. The result is the same but occurs much faster in superinfection.

Question 28

Who is at the greatest risk for a Hep E infection in the U.S.?

Answer 28

Pregnant patients