48-Mechanisms of Viral Pathogenesis

Question 1

What is tropism?

Answer 1

• refers to the way in which different viruses/pathogens have evolved to preferentially target specific host species, or specific cell types within those species

Question 2

What is attenuation?

Answer 2

takes an infectious agent and alters it so that it becomes harmless or less virulent. This is helpful in making vaccines

Question 3

What are the 3 potential outcomes of a viral infection?

Answer 3

• Failed Infection (abortive infection)
• Cell Death (lytic infection)
• Replication Without Cell Death (persistent infection)

Question 4

What is syncytia?

Answer 4

the fusion of neighboring cells into multinucleated giant cells. Allows a virus to spread from cell to cell without antibody detection. Syncytia are fragile and susceptible to lysis

Question 5

What is a persistent infection?

Answer 5

occurs when affected cell is not killed by the virus. This can occur if the virus is gently released from the cell through budding or exocytosis.

Question 6

What is a latent infection?

Answer 6

no virus is synthesized in the cell because the machinery required for it to reproduce is not available. Can be activated if that cell machinery turns on because of variables like stress.

Question 7

What is a transformation?

Answer 7

the continued growth of a cell without senescence. Also called immortalization of the cell.

Question 8

What are the 3 ways an oncogenic virus can immortalize cells?

Answer 8

• Activating or providing growth stimulating genes
• Removing the braking mechanisms that limit DNA synthesis and cell growth
• Preventing apoptosis

Question 9

What is super cool about nonenveloped viruses?

Answer 9

can withstand drying, the effects of detergents and extremes of pH. It is typically spread by respiratory and fecal oral contamination.

Question 10

What is totally awesome about enveloped viruses?

Answer 10

much more fragile than nonenveloped viruses and require an intact envelope for infectivity. Must remain wet and are spread via respiratory droplets, blood, mucus, saliva, semen, injection or organ transplants. Acids and detergents typically destroy them, so they are typically not transmitted through the fecal oral route

Question 11

What is a vector?

Answer 11

things that can spread viral disease. Also, magnitude and direction.

Question 12

What do you get when you cross a mosquito with a mountain climber?

Answer 12

Nothing. You can’t cross a scalar with a vector.

Question 13

What is a reservoir?

Answer 13

things that maintain and amplify the virus in the environment

Question 14

What are zoonoses?

Answer 14

viral diseases that are shared by animals or insects and humans

Question 15

What are arboviruses?

Answer 15

viruses that are from arthropod vectors

Question 16

What is an epidemic?

Answer 16

occur over a large geographic area and generally result from the introduction of a new strain of virus into an immunologically naïve population

Question 17

What is a pandemic?

Answer 17

worldwide epidemics usually resulting from the introduction of a new virus. Like HIV.

Question 18

What is quarantine?

Answer 18

isolation of people or animals that have been exposed or infected by a contagious disease. It’s also a horrible movie.

Question 19

What is nosocomial spread?

Answer 19

infections that are a result of treatment in a hospital or a healthcare service unit. Infections are considered nosocomial if they appear 48 hours or more after hospital admission or within 30 days after discharge